re PR libfortran/78379 (Processor-specific versions for matmul)

2016-12-03  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/78379
        * config/i386/cpuinfo.c:  Move denums for processor vendors,
        processor type, processor subtypes and declaration of
        struct __processor_model into
        * config/i386/cpuinfo.h:  New header file.
        * Makefile.am:  Add dependence of m4/matmul_internal_m4 to
        mamtul files..
        * Makefile.in:  Regenerated.
        * acinclude.m4:  Check for AVX, AVX2 and AVX512F.
        * config.h.in:  Add HAVE_AVX, HAVE_AVX2 and HAVE_AVX512F.
        * configure:  Regenerated.
        * configure.ac:  Use checks for AVX, AVX2 and AVX_512F.
        * m4/matmul_internal.m4:  New file. working part of matmul.m4.
        * m4/matmul.m4:  Implement architecture-specific switching
        for AVX, AVX2 and AVX512F by including matmul_internal.m4
        multiple times.
        * generated/matmul_c10.c: Regenerated.
        * generated/matmul_c16.c: Regenerated.
        * generated/matmul_c4.c: Regenerated.
        * generated/matmul_c8.c: Regenerated.
        * generated/matmul_i1.c: Regenerated.
        * generated/matmul_i16.c: Regenerated.
        * generated/matmul_i2.c: Regenerated.
        * generated/matmul_i4.c: Regenerated.
        * generated/matmul_i8.c: Regenerated.
        * generated/matmul_r10.c: Regenerated.
        * generated/matmul_r16.c: Regenerated.
        * generated/matmul_r4.c: Regenerated.
        * generated/matmul_r8.c: Regenerated.

From-SVN: r243219

22 files changed, 29850 insertions, 516 deletions

diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index d3966f5d54c..03ff0633d18 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,31 @@
+2016-12-03  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/78379
+	* Makefile.am:  Add dependence of m4/matmul_internal_m4 to
+	mamtul files..
+	* Makefile.in:  Regenerated.
+	* acinclude.m4:  Check for AVX, AVX2 and AVX512F.
+	* config.h.in:  Add HAVE_AVX, HAVE_AVX2 and HAVE_AVX512F.
+	* configure:  Regenerated.
+	* configure.ac:  Use checks for AVX, AVX2 and AVX_512F.
+	* m4/matmul_internal.m4:  New file. working part of matmul.m4.
+	* m4/matmul.m4:  Implement architecture-specific switching
+	for AVX, AVX2 and AVX512F by including matmul_internal.m4
+	multiple times.
+	* generated/matmul_c10.c: Regenerated.
+        * generated/matmul_c16.c: Regenerated.
+        * generated/matmul_c4.c: Regenerated.
+        * generated/matmul_c8.c: Regenerated.
+        * generated/matmul_i1.c: Regenerated.
+        * generated/matmul_i16.c: Regenerated.
+        * generated/matmul_i2.c: Regenerated.
+        * generated/matmul_i4.c: Regenerated.
+        * generated/matmul_i8.c: Regenerated.
+        * generated/matmul_r10.c: Regenerated.
+        * generated/matmul_r16.c: Regenerated.
+        * generated/matmul_r4.c: Regenerated.
+        * generated/matmul_r8.c: Regenerated.
+
 2016-11-30  Andre Vehreschild  <vehre@gcc.gnu.org>
 
 	* caf/single.c (_gfortran_caf_get_by_ref): Prevent compile time
diff --git a/libgfortran/Makefile.am b/libgfortran/Makefile.am
index 3db52b85b86..6137d88c997 100644
--- a/libgfortran/Makefile.am
+++ b/libgfortran/Makefile.am
@@ -987,7 +987,7 @@ $(i_product_c): m4/product.m4 $(I_M4_DEPS1)
 $(i_sum_c): m4/sum.m4 $(I_M4_DEPS1)
 	$(M4) -Dfile=$@ -I$(srcdir)/m4 sum.m4 > $@
 
-$(i_matmul_c): m4/matmul.m4 $(I_M4_DEPS)
+$(i_matmul_c): m4/matmul.m4 m4/matmul_internal.m4 $(I_M4_DEPS)
 	$(M4) -Dfile=$@ -I$(srcdir)/m4 matmul.m4 > $@
 
 $(i_matmull_c): m4/matmull.m4 $(I_M4_DEPS)
diff --git a/libgfortran/Makefile.in b/libgfortran/Makefile.in
index f7b34b943c8..4d95723ae59 100644
--- a/libgfortran/Makefile.in
+++ b/libgfortran/Makefile.in
@@ -6053,7 +6053,7 @@ fpu-target.inc: fpu-target.h $(srcdir)/libgfortran.h
 @MAINTAINER_MODE_TRUE@$(i_sum_c): m4/sum.m4 $(I_M4_DEPS1)
 @MAINTAINER_MODE_TRUE@	$(M4) -Dfile=$@ -I$(srcdir)/m4 sum.m4 > $@
 
-@MAINTAINER_MODE_TRUE@$(i_matmul_c): m4/matmul.m4 $(I_M4_DEPS)
+@MAINTAINER_MODE_TRUE@$(i_matmul_c): m4/matmul.m4 m4/matmul_internal.m4 $(I_M4_DEPS)
 @MAINTAINER_MODE_TRUE@	$(M4) -Dfile=$@ -I$(srcdir)/m4 matmul.m4 > $@
 
 @MAINTAINER_MODE_TRUE@$(i_matmull_c): m4/matmull.m4 $(I_M4_DEPS)
diff --git a/libgfortran/acinclude.m4 b/libgfortran/acinclude.m4
index 7280bc37a0b..9a7f461af3c 100644
--- a/libgfortran/acinclude.m4
+++ b/libgfortran/acinclude.m4
@@ -393,3 +393,54 @@ AC_DEFUN([LIBGFOR_CHECK_STRERROR_R], [
 		  [Define if strerror_r takes two arguments and is available in <string.h>.]),)
   CFLAGS="$ac_save_CFLAGS"
 ])
+
+dnl Check for AVX
+
+AC_DEFUN([LIBGFOR_CHECK_AVX], [
+  ac_save_CFLAGS="$CFLAGS"
+  CFLAGS="-O2 -mavx"
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+  void _mm256_zeroall (void)
+        {
+           __builtin_ia32_vzeroall ();
+        }]], [[]])],
+	AC_DEFINE(HAVE_AVX, 1,
+	[Define if AVX instructions can be compiled.]),
+	[])
+  CFLAGS="$ac_save_CFLAGS"
+])
+
+dnl Check for AVX2
+
+AC_DEFUN([LIBGFOR_CHECK_AVX2], [
+  ac_save_CFLAGS="$CFLAGS"
+  CFLAGS="-O2 -mavx2"
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+  typedef long long __v4di __attribute__ ((__vector_size__ (32)));
+	__v4di
+	mm256_is32_andnotsi256  (__v4di __X, __v4di __Y)
+        {
+	   return __builtin_ia32_andnotsi256 (__X, __Y);
+        }]], [[]])],
+	AC_DEFINE(HAVE_AVX2, 1,
+	[Define if AVX2 instructions can be compiled.]),
+	[])
+  CFLAGS="$ac_save_CFLAGS"
+])
+
+dnl Check for AVX512f
+
+AC_DEFUN([LIBGFOR_CHECK_AVX512F], [
+  ac_save_CFLAGS="$CFLAGS"
+  CFLAGS="-O2 -mavx512f"
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+	typedef double __m512d __attribute__ ((__vector_size__ (64)));
+	__m512d _mm512_add (__m512d a)
+	{
+	  return __builtin_ia32_addpd512_mask (a, a, a, 1, 4);
+        }]], [[]])],
+	AC_DEFINE(HAVE_AVX512F, 1,
+	[Define if AVX512f instructions can be compiled.]),
+	[])
+  CFLAGS="$ac_save_CFLAGS"
+])
diff --git a/libgfortran/config.h.in b/libgfortran/config.h.in
index 22449e6892b..b762d0990b6 100644
--- a/libgfortran/config.h.in
+++ b/libgfortran/config.h.in
@@ -78,6 +78,15 @@
 /* Define to 1 if the target supports __attribute__((visibility(...))). */
 #undef HAVE_ATTRIBUTE_VISIBILITY
 
+/* Define if AVX instructions can be compiled. */
+#undef HAVE_AVX
+
+/* Define if AVX2 instructions can be compiled. */
+#undef HAVE_AVX2
+
+/* Define if AVX512f instructions can be compiled. */
+#undef HAVE_AVX512F
+
 /* Define to 1 if you have the `cabs' function. */
 #undef HAVE_CABS
 
diff --git a/libgfortran/configure b/libgfortran/configure
index c0520274a14..45ef93550f2 100755
--- a/libgfortran/configure
+++ b/libgfortran/configure
@@ -26174,6 +26174,93 @@ $as_echo "#define HAVE_CRLF 1" >>confdefs.h
 
 fi
 
+# Check whether we support AVX extensions
+
+  ac_save_CFLAGS="$CFLAGS"
+  CFLAGS="-O2 -mavx"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+  void _mm256_zeroall (void)
+        {
+           __builtin_ia32_vzeroall ();
+        }
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+$as_echo "#define HAVE_AVX 1" >>confdefs.h
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS="$ac_save_CFLAGS"
+
+
+# Check wether we support AVX2 extensions
+
+  ac_save_CFLAGS="$CFLAGS"
+  CFLAGS="-O2 -mavx2"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+  typedef long long __v4di __attribute__ ((__vector_size__ (32)));
+	__v4di
+	mm256_is32_andnotsi256  (__v4di __X, __v4di __Y)
+        {
+	   return __builtin_ia32_andnotsi256 (__X, __Y);
+        }
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+$as_echo "#define HAVE_AVX2 1" >>confdefs.h
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS="$ac_save_CFLAGS"
+
+
+# Check wether we support AVX512f extensions
+
+  ac_save_CFLAGS="$CFLAGS"
+  CFLAGS="-O2 -mavx512f"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+	typedef double __m512d __attribute__ ((__vector_size__ (64)));
+	__m512d _mm512_add (__m512d a)
+	{
+	  return __builtin_ia32_addpd512_mask (a, a, a, 1, 4);
+        }
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+$as_echo "#define HAVE_AVX512F 1" >>confdefs.h
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS="$ac_save_CFLAGS"
+
+
 cat >confcache <<\_ACEOF
 # This file is a shell script that caches the results of configure
 # tests run on this system so they can be shared between configure
diff --git a/libgfortran/configure.ac b/libgfortran/configure.ac
index 3de737dc04f..bb84bafefb7 100644
--- a/libgfortran/configure.ac
+++ b/libgfortran/configure.ac
@@ -609,6 +609,15 @@ LIBGFOR_CHECK_UNLINK_OPEN_FILE
 # Check whether line terminator is LF or CRLF
 LIBGFOR_CHECK_CRLF
 
+# Check whether we support AVX extensions
+LIBGFOR_CHECK_AVX
+
+# Check wether we support AVX2 extensions
+LIBGFOR_CHECK_AVX2
+
+# Check wether we support AVX512f extensions
+LIBGFOR_CHECK_AVX512F
+
 AC_CACHE_SAVE
 
 if test ${multilib} = yes; then
diff --git a/libgfortran/generated/matmul_c10.c b/libgfortran/generated/matmul_c10.c
index c784a2630cd..bf40e375b82 100644
--- a/libgfortran/generated/matmul_c10.c
+++ b/libgfortran/generated/matmul_c10.c
@@ -75,6 +75,2233 @@ extern void matmul_c10 (gfc_array_c10 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_c10);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_c10_avx (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_c10_avx (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_10 * restrict abase;
+  const GFC_COMPLEX_10 * restrict bbase;
+  GFC_COMPLEX_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_10 *a, *b;
+      GFC_COMPLEX_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_10 *restrict abase_x;
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 *restrict dest_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_10 *restrict abase_x;
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 *restrict dest_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_c10_avx2 (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_c10_avx2 (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_10 * restrict abase;
+  const GFC_COMPLEX_10 * restrict bbase;
+  GFC_COMPLEX_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_10 *a, *b;
+      GFC_COMPLEX_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_10 *restrict abase_x;
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 *restrict dest_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_10 *restrict abase_x;
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 *restrict dest_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_c10_avx512f (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_c10_avx512f (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_10 * restrict abase;
+  const GFC_COMPLEX_10 * restrict bbase;
+  GFC_COMPLEX_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_10 *a, *b;
+      GFC_COMPLEX_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_10 *restrict abase_x;
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 *restrict dest_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_10 *restrict abase_x;
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 *restrict dest_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_c10_vanilla (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_10 * restrict abase;
+  const GFC_COMPLEX_10 * restrict bbase;
+  GFC_COMPLEX_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_10 *a, *b;
+      GFC_COMPLEX_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_10 *restrict abase_x;
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 *restrict dest_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_10 *restrict bbase_y;
+	  GFC_COMPLEX_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_10 *restrict abase_x;
+      const GFC_COMPLEX_10 *restrict bbase_y;
+      GFC_COMPLEX_10 *restrict dest_y;
+      GFC_COMPLEX_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_c10 (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_c10 * const restrict retarray, 
+	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_c10_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_c10_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_c10_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_c10_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_c10 (gfc_array_c10 * const restrict retarray, 
 	gfc_array_c10 * const restrict a, gfc_array_c10 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_c10 (gfc_array_c10 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_c16.c b/libgfortran/generated/matmul_c16.c
index 47e1bea729b..6e4545da8f6 100644
--- a/libgfortran/generated/matmul_c16.c
+++ b/libgfortran/generated/matmul_c16.c
@@ -75,6 +75,2233 @@ extern void matmul_c16 (gfc_array_c16 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_c16);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_c16_avx (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_c16_avx (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_16 * restrict abase;
+  const GFC_COMPLEX_16 * restrict bbase;
+  GFC_COMPLEX_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_16 *a, *b;
+      GFC_COMPLEX_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_16 *restrict abase_x;
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 *restrict dest_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_16 *restrict abase_x;
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 *restrict dest_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_c16_avx2 (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_c16_avx2 (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_16 * restrict abase;
+  const GFC_COMPLEX_16 * restrict bbase;
+  GFC_COMPLEX_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_16 *a, *b;
+      GFC_COMPLEX_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_16 *restrict abase_x;
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 *restrict dest_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_16 *restrict abase_x;
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 *restrict dest_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_c16_avx512f (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_c16_avx512f (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_16 * restrict abase;
+  const GFC_COMPLEX_16 * restrict bbase;
+  GFC_COMPLEX_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_16 *a, *b;
+      GFC_COMPLEX_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_16 *restrict abase_x;
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 *restrict dest_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_16 *restrict abase_x;
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 *restrict dest_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_c16_vanilla (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_16 * restrict abase;
+  const GFC_COMPLEX_16 * restrict bbase;
+  GFC_COMPLEX_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_16 *a, *b;
+      GFC_COMPLEX_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_16 *restrict abase_x;
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 *restrict dest_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_16 *restrict bbase_y;
+	  GFC_COMPLEX_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_16 *restrict abase_x;
+      const GFC_COMPLEX_16 *restrict bbase_y;
+      GFC_COMPLEX_16 *restrict dest_y;
+      GFC_COMPLEX_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_c16 (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_c16 * const restrict retarray, 
+	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_c16_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_c16_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_c16_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_c16_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_c16 (gfc_array_c16 * const restrict retarray, 
 	gfc_array_c16 * const restrict a, gfc_array_c16 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_c16 (gfc_array_c16 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_c4.c b/libgfortran/generated/matmul_c4.c
index 4eb18965d91..6f7d5c2115e 100644
--- a/libgfortran/generated/matmul_c4.c
+++ b/libgfortran/generated/matmul_c4.c
@@ -75,6 +75,2233 @@ extern void matmul_c4 (gfc_array_c4 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_c4);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_c4_avx (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_c4_avx (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_4 * restrict abase;
+  const GFC_COMPLEX_4 * restrict bbase;
+  GFC_COMPLEX_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_4 *a, *b;
+      GFC_COMPLEX_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_4 *restrict abase_x;
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 *restrict dest_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_4 *restrict abase_x;
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 *restrict dest_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_c4_avx2 (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_c4_avx2 (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_4 * restrict abase;
+  const GFC_COMPLEX_4 * restrict bbase;
+  GFC_COMPLEX_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_4 *a, *b;
+      GFC_COMPLEX_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_4 *restrict abase_x;
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 *restrict dest_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_4 *restrict abase_x;
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 *restrict dest_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_c4_avx512f (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_c4_avx512f (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_4 * restrict abase;
+  const GFC_COMPLEX_4 * restrict bbase;
+  GFC_COMPLEX_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_4 *a, *b;
+      GFC_COMPLEX_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_4 *restrict abase_x;
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 *restrict dest_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_4 *restrict abase_x;
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 *restrict dest_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_c4_vanilla (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_4 * restrict abase;
+  const GFC_COMPLEX_4 * restrict bbase;
+  GFC_COMPLEX_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_4 *a, *b;
+      GFC_COMPLEX_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_4 *restrict abase_x;
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 *restrict dest_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_4 *restrict bbase_y;
+	  GFC_COMPLEX_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_4 *restrict abase_x;
+      const GFC_COMPLEX_4 *restrict bbase_y;
+      GFC_COMPLEX_4 *restrict dest_y;
+      GFC_COMPLEX_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_c4 (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_c4 * const restrict retarray, 
+	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_c4_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_c4_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_c4_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_c4_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_c4 (gfc_array_c4 * const restrict retarray, 
 	gfc_array_c4 * const restrict a, gfc_array_c4 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_c4 (gfc_array_c4 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_c8.c b/libgfortran/generated/matmul_c8.c
index 2321b9effbd..06916c334e1 100644
--- a/libgfortran/generated/matmul_c8.c
+++ b/libgfortran/generated/matmul_c8.c
@@ -75,6 +75,2233 @@ extern void matmul_c8 (gfc_array_c8 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_c8);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_c8_avx (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_c8_avx (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_8 * restrict abase;
+  const GFC_COMPLEX_8 * restrict bbase;
+  GFC_COMPLEX_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_8 *a, *b;
+      GFC_COMPLEX_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_8 *restrict abase_x;
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 *restrict dest_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_8 *restrict abase_x;
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 *restrict dest_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_c8_avx2 (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_c8_avx2 (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_8 * restrict abase;
+  const GFC_COMPLEX_8 * restrict bbase;
+  GFC_COMPLEX_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_8 *a, *b;
+      GFC_COMPLEX_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_8 *restrict abase_x;
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 *restrict dest_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_8 *restrict abase_x;
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 *restrict dest_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_c8_avx512f (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_c8_avx512f (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_8 * restrict abase;
+  const GFC_COMPLEX_8 * restrict bbase;
+  GFC_COMPLEX_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_8 *a, *b;
+      GFC_COMPLEX_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_8 *restrict abase_x;
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 *restrict dest_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_8 *restrict abase_x;
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 *restrict dest_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_c8_vanilla (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_COMPLEX_8 * restrict abase;
+  const GFC_COMPLEX_8 * restrict bbase;
+  GFC_COMPLEX_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_COMPLEX_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_COMPLEX_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_COMPLEX_8 *a, *b;
+      GFC_COMPLEX_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_COMPLEX_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_COMPLEX_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_COMPLEX_8 *restrict abase_x;
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 *restrict dest_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_COMPLEX_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_COMPLEX_8 *restrict bbase_y;
+	  GFC_COMPLEX_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_COMPLEX_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_COMPLEX_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_COMPLEX_8 *restrict abase_x;
+      const GFC_COMPLEX_8 *restrict bbase_y;
+      GFC_COMPLEX_8 *restrict dest_y;
+      GFC_COMPLEX_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_COMPLEX_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_c8 (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_c8 * const restrict retarray, 
+	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_c8_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_c8_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_c8_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_c8_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_c8 (gfc_array_c8 * const restrict retarray, 
 	gfc_array_c8 * const restrict a, gfc_array_c8 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_c8 (gfc_array_c8 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_i1.c b/libgfortran/generated/matmul_i1.c
index 81c067b2ce1..2cce9d13b9f 100644
--- a/libgfortran/generated/matmul_i1.c
+++ b/libgfortran/generated/matmul_i1.c
@@ -75,6 +75,2233 @@ extern void matmul_i1 (gfc_array_i1 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_i1);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_i1_avx (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_i1_avx (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_1 * restrict abase;
+  const GFC_INTEGER_1 * restrict bbase;
+  GFC_INTEGER_1 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_1));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_1 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_1 *a, *b;
+      GFC_INTEGER_1 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_1 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_1)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_1 *restrict abase_x;
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 *restrict dest_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_1) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_1)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_1) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_1 *restrict abase_x;
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 *restrict dest_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_i1_avx2 (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_i1_avx2 (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_1 * restrict abase;
+  const GFC_INTEGER_1 * restrict bbase;
+  GFC_INTEGER_1 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_1));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_1 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_1 *a, *b;
+      GFC_INTEGER_1 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_1 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_1)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_1 *restrict abase_x;
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 *restrict dest_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_1) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_1)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_1) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_1 *restrict abase_x;
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 *restrict dest_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_i1_avx512f (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_i1_avx512f (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_1 * restrict abase;
+  const GFC_INTEGER_1 * restrict bbase;
+  GFC_INTEGER_1 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_1));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_1 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_1 *a, *b;
+      GFC_INTEGER_1 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_1 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_1)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_1 *restrict abase_x;
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 *restrict dest_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_1) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_1)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_1) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_1 *restrict abase_x;
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 *restrict dest_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_i1_vanilla (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_1 * restrict abase;
+  const GFC_INTEGER_1 * restrict bbase;
+  GFC_INTEGER_1 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_1));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_1 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_1 *a, *b;
+      GFC_INTEGER_1 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_1 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_1)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_1 *restrict abase_x;
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 *restrict dest_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_1) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_1 *restrict bbase_y;
+	  GFC_INTEGER_1 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_1)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_1) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_1 *restrict abase_x;
+      const GFC_INTEGER_1 *restrict bbase_y;
+      GFC_INTEGER_1 *restrict dest_y;
+      GFC_INTEGER_1 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_1) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_i1 (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_i1 * const restrict retarray, 
+	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_i1_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_i1_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_i1_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_i1_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_i1 (gfc_array_i1 * const restrict retarray, 
 	gfc_array_i1 * const restrict a, gfc_array_i1 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_i1 (gfc_array_i1 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_i16.c b/libgfortran/generated/matmul_i16.c
index d1b1761014a..76a605fb759 100644
--- a/libgfortran/generated/matmul_i16.c
+++ b/libgfortran/generated/matmul_i16.c
@@ -75,6 +75,2233 @@ extern void matmul_i16 (gfc_array_i16 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_i16);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_i16_avx (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_i16_avx (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_16 * restrict abase;
+  const GFC_INTEGER_16 * restrict bbase;
+  GFC_INTEGER_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_16 *a, *b;
+      GFC_INTEGER_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_16 *restrict abase_x;
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 *restrict dest_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_16 *restrict abase_x;
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 *restrict dest_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_i16_avx2 (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_i16_avx2 (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_16 * restrict abase;
+  const GFC_INTEGER_16 * restrict bbase;
+  GFC_INTEGER_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_16 *a, *b;
+      GFC_INTEGER_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_16 *restrict abase_x;
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 *restrict dest_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_16 *restrict abase_x;
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 *restrict dest_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_i16_avx512f (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_i16_avx512f (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_16 * restrict abase;
+  const GFC_INTEGER_16 * restrict bbase;
+  GFC_INTEGER_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_16 *a, *b;
+      GFC_INTEGER_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_16 *restrict abase_x;
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 *restrict dest_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_16 *restrict abase_x;
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 *restrict dest_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_i16_vanilla (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_16 * restrict abase;
+  const GFC_INTEGER_16 * restrict bbase;
+  GFC_INTEGER_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_16 *a, *b;
+      GFC_INTEGER_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_16 *restrict abase_x;
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 *restrict dest_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_16 *restrict bbase_y;
+	  GFC_INTEGER_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_16 *restrict abase_x;
+      const GFC_INTEGER_16 *restrict bbase_y;
+      GFC_INTEGER_16 *restrict dest_y;
+      GFC_INTEGER_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_i16 (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_i16 * const restrict retarray, 
+	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_i16_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_i16_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_i16_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_i16_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_i16 (gfc_array_i16 * const restrict retarray, 
 	gfc_array_i16 * const restrict a, gfc_array_i16 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_i16 (gfc_array_i16 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_i2.c b/libgfortran/generated/matmul_i2.c
index 5a06fcc6a2c..324197a013d 100644
--- a/libgfortran/generated/matmul_i2.c
+++ b/libgfortran/generated/matmul_i2.c
@@ -75,6 +75,2233 @@ extern void matmul_i2 (gfc_array_i2 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_i2);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_i2_avx (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_i2_avx (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_2 * restrict abase;
+  const GFC_INTEGER_2 * restrict bbase;
+  GFC_INTEGER_2 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_2));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_2 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_2 *a, *b;
+      GFC_INTEGER_2 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_2 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_2)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_2 *restrict abase_x;
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 *restrict dest_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_2) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_2)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_2) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_2 *restrict abase_x;
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 *restrict dest_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_i2_avx2 (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_i2_avx2 (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_2 * restrict abase;
+  const GFC_INTEGER_2 * restrict bbase;
+  GFC_INTEGER_2 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_2));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_2 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_2 *a, *b;
+      GFC_INTEGER_2 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_2 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_2)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_2 *restrict abase_x;
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 *restrict dest_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_2) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_2)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_2) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_2 *restrict abase_x;
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 *restrict dest_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_i2_avx512f (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_i2_avx512f (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_2 * restrict abase;
+  const GFC_INTEGER_2 * restrict bbase;
+  GFC_INTEGER_2 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_2));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_2 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_2 *a, *b;
+      GFC_INTEGER_2 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_2 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_2)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_2 *restrict abase_x;
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 *restrict dest_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_2) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_2)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_2) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_2 *restrict abase_x;
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 *restrict dest_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_i2_vanilla (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_2 * restrict abase;
+  const GFC_INTEGER_2 * restrict bbase;
+  GFC_INTEGER_2 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_2));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_2 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_2 *a, *b;
+      GFC_INTEGER_2 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_2 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_2)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_2 *restrict abase_x;
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 *restrict dest_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_2) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_2 *restrict bbase_y;
+	  GFC_INTEGER_2 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_2)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_2) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_2 *restrict abase_x;
+      const GFC_INTEGER_2 *restrict bbase_y;
+      GFC_INTEGER_2 *restrict dest_y;
+      GFC_INTEGER_2 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_2) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_i2 (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_i2 * const restrict retarray, 
+	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_i2_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_i2_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_i2_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_i2_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_i2 (gfc_array_i2 * const restrict retarray, 
 	gfc_array_i2 * const restrict a, gfc_array_i2 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_i2 (gfc_array_i2 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_i4.c b/libgfortran/generated/matmul_i4.c
index aee8e4d55d5..bd31c7cebe5 100644
--- a/libgfortran/generated/matmul_i4.c
+++ b/libgfortran/generated/matmul_i4.c
@@ -75,6 +75,2233 @@ extern void matmul_i4 (gfc_array_i4 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_i4);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_i4_avx (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_i4_avx (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_4 * restrict abase;
+  const GFC_INTEGER_4 * restrict bbase;
+  GFC_INTEGER_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_4 *a, *b;
+      GFC_INTEGER_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_4 *restrict abase_x;
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 *restrict dest_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_4 *restrict abase_x;
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 *restrict dest_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_i4_avx2 (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_i4_avx2 (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_4 * restrict abase;
+  const GFC_INTEGER_4 * restrict bbase;
+  GFC_INTEGER_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_4 *a, *b;
+      GFC_INTEGER_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_4 *restrict abase_x;
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 *restrict dest_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_4 *restrict abase_x;
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 *restrict dest_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_i4_avx512f (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_i4_avx512f (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_4 * restrict abase;
+  const GFC_INTEGER_4 * restrict bbase;
+  GFC_INTEGER_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_4 *a, *b;
+      GFC_INTEGER_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_4 *restrict abase_x;
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 *restrict dest_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_4 *restrict abase_x;
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 *restrict dest_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_i4_vanilla (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_4 * restrict abase;
+  const GFC_INTEGER_4 * restrict bbase;
+  GFC_INTEGER_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_4 *a, *b;
+      GFC_INTEGER_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_4 *restrict abase_x;
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 *restrict dest_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_4 *restrict bbase_y;
+	  GFC_INTEGER_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_4 *restrict abase_x;
+      const GFC_INTEGER_4 *restrict bbase_y;
+      GFC_INTEGER_4 *restrict dest_y;
+      GFC_INTEGER_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_i4 (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_i4 * const restrict retarray, 
+	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_i4_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_i4_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_i4_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_i4_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_i4 (gfc_array_i4 * const restrict retarray, 
 	gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_i4 (gfc_array_i4 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_i8.c b/libgfortran/generated/matmul_i8.c
index 902b2840751..c4d0327b7aa 100644
--- a/libgfortran/generated/matmul_i8.c
+++ b/libgfortran/generated/matmul_i8.c
@@ -75,6 +75,2233 @@ extern void matmul_i8 (gfc_array_i8 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_i8);
 
+
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_i8_avx (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_i8_avx (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_8 * restrict abase;
+  const GFC_INTEGER_8 * restrict bbase;
+  GFC_INTEGER_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_8 *a, *b;
+      GFC_INTEGER_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_8 *restrict abase_x;
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 *restrict dest_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_8 *restrict abase_x;
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 *restrict dest_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_i8_avx2 (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_i8_avx2 (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_8 * restrict abase;
+  const GFC_INTEGER_8 * restrict bbase;
+  GFC_INTEGER_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_8 *a, *b;
+      GFC_INTEGER_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_8 *restrict abase_x;
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 *restrict dest_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_8 *restrict abase_x;
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 *restrict dest_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_i8_avx512f (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_i8_avx512f (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_8 * restrict abase;
+  const GFC_INTEGER_8 * restrict bbase;
+  GFC_INTEGER_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_8 *a, *b;
+      GFC_INTEGER_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_8 *restrict abase_x;
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 *restrict dest_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_8 *restrict abase_x;
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 *restrict dest_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_i8_vanilla (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_INTEGER_8 * restrict abase;
+  const GFC_INTEGER_8 * restrict bbase;
+  GFC_INTEGER_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_INTEGER_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_INTEGER_8 *a, *b;
+      GFC_INTEGER_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_INTEGER_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_INTEGER_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_INTEGER_8 *restrict abase_x;
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 *restrict dest_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_INTEGER_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_INTEGER_8 *restrict bbase_y;
+	  GFC_INTEGER_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_INTEGER_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_INTEGER_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_INTEGER_8 *restrict abase_x;
+      const GFC_INTEGER_8 *restrict bbase_y;
+      GFC_INTEGER_8 *restrict dest_y;
+      GFC_INTEGER_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_INTEGER_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_i8 (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_i8 * const restrict retarray, 
+	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_i8_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_i8_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_i8_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_i8_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_i8 (gfc_array_i8 * const restrict retarray, 
 	gfc_array_i8 * const restrict a, gfc_array_i8 * const restrict b, int try_blas,
@@ -607,4 +2834,10 @@ matmul_i8 (gfc_array_i8 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_r10.c b/libgfortran/generated/matmul_r10.c
index 8bb1e6297bb..b9fb10b0f67 100644
--- a/libgfortran/generated/matmul_r10.c
+++ b/libgfortran/generated/matmul_r10.c
@@ -75,6 +75,2237 @@ extern void matmul_r10 (gfc_array_r10 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_r10);
 
+#if defined(HAVE_AVX) && defined(HAVE_AVX2)
+/* REAL types generate identical code for AVX and AVX2.  Only generate
+   an AVX2 function if we are dealing with integer.  */
+#undef HAVE_AVX2
+#endif
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_r10_avx (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_r10_avx (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_10 * restrict abase;
+  const GFC_REAL_10 * restrict bbase;
+  GFC_REAL_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_10 *a, *b;
+      GFC_REAL_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_10 *restrict abase_x;
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 *restrict dest_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_10 *restrict abase_x;
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 *restrict dest_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_r10_avx2 (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_r10_avx2 (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_10 * restrict abase;
+  const GFC_REAL_10 * restrict bbase;
+  GFC_REAL_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_10 *a, *b;
+      GFC_REAL_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_10 *restrict abase_x;
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 *restrict dest_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_10 *restrict abase_x;
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 *restrict dest_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_r10_avx512f (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_r10_avx512f (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_10 * restrict abase;
+  const GFC_REAL_10 * restrict bbase;
+  GFC_REAL_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_10 *a, *b;
+      GFC_REAL_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_10 *restrict abase_x;
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 *restrict dest_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_10 *restrict abase_x;
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 *restrict dest_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_r10_vanilla (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_10 * restrict abase;
+  const GFC_REAL_10 * restrict bbase;
+  GFC_REAL_10 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_10));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_10 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_10 *a, *b;
+      GFC_REAL_10 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_10 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_10)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_10 *restrict abase_x;
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 *restrict dest_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_10) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_10 *restrict bbase_y;
+	  GFC_REAL_10 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_10)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_10) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_10 *restrict abase_x;
+      const GFC_REAL_10 *restrict bbase_y;
+      GFC_REAL_10 *restrict dest_y;
+      GFC_REAL_10 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_10) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_r10 (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_r10 * const restrict retarray, 
+	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_r10_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_r10_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_r10_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_r10_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_r10 (gfc_array_r10 * const restrict retarray, 
 	gfc_array_r10 * const restrict a, gfc_array_r10 * const restrict b, int try_blas,
@@ -607,4 +2838,10 @@ matmul_r10 (gfc_array_r10 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_r16.c b/libgfortran/generated/matmul_r16.c
index 4ebd104594b..65ac801b234 100644
--- a/libgfortran/generated/matmul_r16.c
+++ b/libgfortran/generated/matmul_r16.c
@@ -75,6 +75,2237 @@ extern void matmul_r16 (gfc_array_r16 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_r16);
 
+#if defined(HAVE_AVX) && defined(HAVE_AVX2)
+/* REAL types generate identical code for AVX and AVX2.  Only generate
+   an AVX2 function if we are dealing with integer.  */
+#undef HAVE_AVX2
+#endif
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_r16_avx (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_r16_avx (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_16 * restrict abase;
+  const GFC_REAL_16 * restrict bbase;
+  GFC_REAL_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_16 *a, *b;
+      GFC_REAL_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_16 *restrict abase_x;
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 *restrict dest_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_16 *restrict abase_x;
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 *restrict dest_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_r16_avx2 (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_r16_avx2 (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_16 * restrict abase;
+  const GFC_REAL_16 * restrict bbase;
+  GFC_REAL_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_16 *a, *b;
+      GFC_REAL_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_16 *restrict abase_x;
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 *restrict dest_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_16 *restrict abase_x;
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 *restrict dest_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_r16_avx512f (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_r16_avx512f (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_16 * restrict abase;
+  const GFC_REAL_16 * restrict bbase;
+  GFC_REAL_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_16 *a, *b;
+      GFC_REAL_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_16 *restrict abase_x;
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 *restrict dest_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_16 *restrict abase_x;
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 *restrict dest_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_r16_vanilla (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_16 * restrict abase;
+  const GFC_REAL_16 * restrict bbase;
+  GFC_REAL_16 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_16));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_16 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_16 *a, *b;
+      GFC_REAL_16 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_16 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_16)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_16 *restrict abase_x;
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 *restrict dest_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_16) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_16 *restrict bbase_y;
+	  GFC_REAL_16 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_16)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_16) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_16 *restrict abase_x;
+      const GFC_REAL_16 *restrict bbase_y;
+      GFC_REAL_16 *restrict dest_y;
+      GFC_REAL_16 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_16) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_r16 (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_r16 * const restrict retarray, 
+	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_r16_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_r16_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_r16_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_r16_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_r16 (gfc_array_r16 * const restrict retarray, 
 	gfc_array_r16 * const restrict a, gfc_array_r16 * const restrict b, int try_blas,
@@ -607,4 +2838,10 @@ matmul_r16 (gfc_array_r16 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_r4.c b/libgfortran/generated/matmul_r4.c
index cf3ffa35232..2a85d6b3bcc 100644
--- a/libgfortran/generated/matmul_r4.c
+++ b/libgfortran/generated/matmul_r4.c
@@ -75,6 +75,2237 @@ extern void matmul_r4 (gfc_array_r4 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_r4);
 
+#if defined(HAVE_AVX) && defined(HAVE_AVX2)
+/* REAL types generate identical code for AVX and AVX2.  Only generate
+   an AVX2 function if we are dealing with integer.  */
+#undef HAVE_AVX2
+#endif
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_r4_avx (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_r4_avx (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_4 * restrict abase;
+  const GFC_REAL_4 * restrict bbase;
+  GFC_REAL_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_4 *a, *b;
+      GFC_REAL_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_4 *restrict abase_x;
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 *restrict dest_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_4 *restrict abase_x;
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 *restrict dest_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_r4_avx2 (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_r4_avx2 (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_4 * restrict abase;
+  const GFC_REAL_4 * restrict bbase;
+  GFC_REAL_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_4 *a, *b;
+      GFC_REAL_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_4 *restrict abase_x;
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 *restrict dest_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_4 *restrict abase_x;
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 *restrict dest_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_r4_avx512f (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_r4_avx512f (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_4 * restrict abase;
+  const GFC_REAL_4 * restrict bbase;
+  GFC_REAL_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_4 *a, *b;
+      GFC_REAL_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_4 *restrict abase_x;
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 *restrict dest_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_4 *restrict abase_x;
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 *restrict dest_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_r4_vanilla (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_4 * restrict abase;
+  const GFC_REAL_4 * restrict bbase;
+  GFC_REAL_4 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_4));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_4 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_4 *a, *b;
+      GFC_REAL_4 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_4 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_4)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_4 *restrict abase_x;
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 *restrict dest_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_4) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_4 *restrict bbase_y;
+	  GFC_REAL_4 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_4)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_4) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_4 *restrict abase_x;
+      const GFC_REAL_4 *restrict bbase_y;
+      GFC_REAL_4 *restrict dest_y;
+      GFC_REAL_4 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_4) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_r4 (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_r4 * const restrict retarray, 
+	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_r4_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_r4_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_r4_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_r4_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_r4 (gfc_array_r4 * const restrict retarray, 
 	gfc_array_r4 * const restrict a, gfc_array_r4 * const restrict b, int try_blas,
@@ -607,4 +2838,10 @@ matmul_r4 (gfc_array_r4 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/generated/matmul_r8.c b/libgfortran/generated/matmul_r8.c
index 9a70a23df0b..78bf52ef6fe 100644
--- a/libgfortran/generated/matmul_r8.c
+++ b/libgfortran/generated/matmul_r8.c
@@ -75,6 +75,2237 @@ extern void matmul_r8 (gfc_array_r8 * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_r8);
 
+#if defined(HAVE_AVX) && defined(HAVE_AVX2)
+/* REAL types generate identical code for AVX and AVX2.  Only generate
+   an AVX2 function if we are dealing with integer.  */
+#undef HAVE_AVX2
+#endif
+
+
+/* Put exhaustive list of possible architectures here here, ORed together.  */
+
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
+
+#ifdef HAVE_AVX
+static void
+matmul_r8_avx (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static void
+matmul_r8_avx (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_8 * restrict abase;
+  const GFC_REAL_8 * restrict bbase;
+  GFC_REAL_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_8 *a, *b;
+      GFC_REAL_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_8 *restrict abase_x;
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 *restrict dest_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_8 *restrict abase_x;
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 *restrict dest_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+static void
+matmul_r8_avx2 (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static void
+matmul_r8_avx2 (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_8 * restrict abase;
+  const GFC_REAL_8 * restrict bbase;
+  GFC_REAL_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_8 *a, *b;
+      GFC_REAL_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_8 *restrict abase_x;
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 *restrict dest_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_8 *restrict abase_x;
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 *restrict dest_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+static void
+matmul_r8_avx512f (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static void
+matmul_r8_avx512f (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_8 * restrict abase;
+  const GFC_REAL_8 * restrict bbase;
+  GFC_REAL_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_8 *a, *b;
+      GFC_REAL_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_8 *restrict abase_x;
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 *restrict dest_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_8 *restrict abase_x;
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 *restrict dest_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+#endif  /* HAVE_AVX512F */
+
+/* Function to fall back to if there is no special processor-specific version.  */
+static void
+matmul_r8_vanilla (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const GFC_REAL_8 * restrict abase;
+  const GFC_REAL_8 * restrict bbase;
+  GFC_REAL_8 * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_REAL_8));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const GFC_REAL_8 one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const GFC_REAL_8 *a, *b;
+      GFC_REAL_8 *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      GFC_REAL_8 t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = (GFC_REAL_8)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const GFC_REAL_8 *restrict abase_x;
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 *restrict dest_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = (GFC_REAL_8) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const GFC_REAL_8 *restrict bbase_y;
+	  GFC_REAL_8 s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = (GFC_REAL_8)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = (GFC_REAL_8) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const GFC_REAL_8 *restrict abase_x;
+      const GFC_REAL_8 *restrict bbase_y;
+      GFC_REAL_8 *restrict dest_y;
+      GFC_REAL_8 s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = (GFC_REAL_8) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+
+
+/* Compiling main function, with selection code for the processor.  */
+
+/* Currently, this is i386 only.  Adjust for other architectures.  */
+
+#include <config/i386/cpuinfo.h>
+void matmul_r8 (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) (gfc_array_r8 * const restrict retarray, 
+	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
+
+  if (matmul_p == NULL)
+    {
+      matmul_p = matmul_r8_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
+	{
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
+	    {
+	      matmul_p = matmul_r8_avx512f;
+	      goto tailcall;
+	    }
+
+#endif  /* HAVE_AVX512F */
+
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
+	    {
+	      matmul_p = matmul_r8_avx2;
+	      goto tailcall;
+	    }
+
+#endif
+
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_r8_avx;
+	      goto tailcall;
+	    }
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
 void
 matmul_r8 (gfc_array_r8 * const restrict retarray, 
 	gfc_array_r8 * const restrict a, gfc_array_r8 * const restrict b, int try_blas,
@@ -607,4 +2838,10 @@ matmul_r8 (gfc_array_r8 * const restrict retarray,
 	}
     }
 }
+#undef POW3
+#undef min
+#undef max
+
 #endif
+#endif
+
diff --git a/libgfortran/m4/matmul.m4 b/libgfortran/m4/matmul.m4
index 77ed4408425..4e5bf606209 100644
--- a/libgfortran/m4/matmul.m4
+++ b/libgfortran/m4/matmul.m4
@@ -76,537 +76,105 @@ extern void matmul_'rtype_code` ('rtype` * const restrict retarray,
 	int blas_limit, blas_call gemm);
 export_proto(matmul_'rtype_code`);
 
-void
-matmul_'rtype_code` ('rtype` * const restrict retarray, 
-	'rtype` * const restrict a, 'rtype` * const restrict b, int try_blas,
-	int blas_limit, blas_call gemm)
-{
-  const 'rtype_name` * restrict abase;
-  const 'rtype_name` * restrict bbase;
-  'rtype_name` * restrict dest;
-
-  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
-  index_type x, y, n, count, xcount, ycount;
-
-  assert (GFC_DESCRIPTOR_RANK (a) == 2
-          || GFC_DESCRIPTOR_RANK (b) == 2);
-
-/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
-
-   Either A or B (but not both) can be rank 1:
-
-   o One-dimensional argument A is implicitly treated as a row matrix
-     dimensioned [1,count], so xcount=1.
-
-   o One-dimensional argument B is implicitly treated as a column matrix
-     dimensioned [count, 1], so ycount=1.
-*/
+'ifelse(rtype_letter,`r',dnl
+`#if defined(HAVE_AVX) && defined(HAVE_AVX2)
+/* REAL types generate identical code for AVX and AVX2.  Only generate
+   an AVX2 function if we are dealing with integer.  */
+#undef HAVE_AVX2
+#endif')
+`
 
-  if (retarray->base_addr == NULL)
-    {
-      if (GFC_DESCRIPTOR_RANK (a) == 1)
-        {
-	  GFC_DIMENSION_SET(retarray->dim[0], 0,
-	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
-        }
-      else if (GFC_DESCRIPTOR_RANK (b) == 1)
-        {
-	  GFC_DIMENSION_SET(retarray->dim[0], 0,
-	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
-        }
-      else
-        {
-	  GFC_DIMENSION_SET(retarray->dim[0], 0,
-	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
-
-          GFC_DIMENSION_SET(retarray->dim[1], 0,
-	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
-			    GFC_DESCRIPTOR_EXTENT(retarray,0));
-        }
+/* Put exhaustive list of possible architectures here here, ORed together.  */
 
-      retarray->base_addr
-	= xmallocarray (size0 ((array_t *) retarray), sizeof ('rtype_name`));
-      retarray->offset = 0;
-    }
-  else if (unlikely (compile_options.bounds_check))
-    {
-      index_type ret_extent, arg_extent;
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)
 
-      if (GFC_DESCRIPTOR_RANK (a) == 1)
-	{
-	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
-	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
-	  if (arg_extent != ret_extent)
-	    runtime_error ("Incorrect extent in return array in"
-			   " MATMUL intrinsic: is %ld, should be %ld",
-			   (long int) ret_extent, (long int) arg_extent);
-	}
-      else if (GFC_DESCRIPTOR_RANK (b) == 1)
-	{
-	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
-	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
-	  if (arg_extent != ret_extent)
-	    runtime_error ("Incorrect extent in return array in"
-			   " MATMUL intrinsic: is %ld, should be %ld",
-			   (long int) ret_extent, (long int) arg_extent);
-	}
-      else
-	{
-	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
-	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
-	  if (arg_extent != ret_extent)
-	    runtime_error ("Incorrect extent in return array in"
-			   " MATMUL intrinsic for dimension 1:"
-			   " is %ld, should be %ld",
-			   (long int) ret_extent, (long int) arg_extent);
-
-	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
-	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
-	  if (arg_extent != ret_extent)
-	    runtime_error ("Incorrect extent in return array in"
-			   " MATMUL intrinsic for dimension 2:"
-			   " is %ld, should be %ld",
-			   (long int) ret_extent, (long int) arg_extent);
-	}
-    }
-'
-sinclude(`matmul_asm_'rtype_code`.m4')dnl
-`
-  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
-    {
-      /* One-dimensional result may be addressed in the code below
-	 either as a row or a column matrix. We want both cases to
-	 work. */
-      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
-    }
-  else
-    {
-      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
-      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
-    }
+#ifdef HAVE_AVX
+'define(`matmul_name',`matmul_'rtype_code`_avx')dnl
+`static void
+'matmul_name` ('rtype` * const restrict retarray, 
+	'rtype` * const restrict a, 'rtype` * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
+static' include(matmul_internal.m4)dnl
+`#endif /* HAVE_AVX */
+
+#ifdef HAVE_AVX2
+'define(`matmul_name',`matmul_'rtype_code`_avx2')dnl
+`static void
+'matmul_name` ('rtype` * const restrict retarray, 
+	'rtype` * const restrict a, 'rtype` * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx2")));
+static' include(matmul_internal.m4)dnl
+`#endif /* HAVE_AVX2 */
+
+#ifdef HAVE_AVX512F
+'define(`matmul_name',`matmul_'rtype_code`_avx512f')dnl
+`static void
+'matmul_name` ('rtype` * const restrict retarray, 
+	'rtype` * const restrict a, 'rtype` * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
+static' include(matmul_internal.m4)dnl
+`#endif  /* HAVE_AVX512F */
 
+/* Function to fall back to if there is no special processor-specific version.  */
+'define(`matmul_name',`matmul_'rtype_code`_vanilla')dnl
+`static' include(matmul_internal.m4)dnl
 
-  if (GFC_DESCRIPTOR_RANK (a) == 1)
-    {
-      /* Treat it as a a row matrix A[1,count]. */
-      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
-      aystride = 1;
-
-      xcount = 1;
-      count = GFC_DESCRIPTOR_EXTENT(a,0);
-    }
-  else
-    {
-      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
-      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+`/* Compiling main function, with selection code for the processor.  */
 
-      count = GFC_DESCRIPTOR_EXTENT(a,1);
-      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
-    }
+/* Currently, this is i386 only.  Adjust for other architectures.  */
 
-  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
-    {
-      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
-	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
-    }
-
-  if (GFC_DESCRIPTOR_RANK (b) == 1)
-    {
-      /* Treat it as a column matrix B[count,1] */
-      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
-
-      /* bystride should never be used for 1-dimensional b.
-	 in case it is we want it to cause a segfault, rather than
-	 an incorrect result. */
-      bystride = 0xDEADBEEF;
-      ycount = 1;
-    }
-  else
-    {
-      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
-      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
-      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
-    }
-
-  abase = a->base_addr;
-  bbase = b->base_addr;
-  dest = retarray->base_addr;
-
-  /* Now that everything is set up, we perform the multiplication
-     itself.  */
-
-#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
-#define min(a,b) ((a) <= (b) ? (a) : (b))
-#define max(a,b) ((a) >= (b) ? (a) : (b))
-
-  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
-      && (bxstride == 1 || bystride == 1)
-      && (((float) xcount) * ((float) ycount) * ((float) count)
-          > POW3(blas_limit)))
-    {
-      const int m = xcount, n = ycount, k = count, ldc = rystride;
-      const 'rtype_name` one = 1, zero = 0;
-      const int lda = (axstride == 1) ? aystride : axstride,
-		ldb = (bxstride == 1) ? bystride : bxstride;
+#include <config/i386/cpuinfo.h>
+void matmul_'rtype_code` ('rtype` * const restrict retarray, 
+	'rtype` * const restrict a, 'rtype` * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  static void (*matmul_p) ('rtype` * const restrict retarray, 
+	'rtype` * const restrict a, 'rtype` * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm) = NULL;
 
-      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
-	{
-	  assert (gemm != NULL);
-	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
-		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
-		&ldc, 1, 1);
-	  return;
-	}
-    }
-
-  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+  if (matmul_p == NULL)
     {
-      /* This block of code implements a tuned matmul, derived from
-         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
-
-               Bo Kagstrom and Per Ling
-               Department of Computing Science
-               Umea University
-               S-901 87 Umea, Sweden
-
-	 from netlib.org, translated to C, and modified for matmul.m4.  */
-
-      const 'rtype_name` *a, *b;
-      'rtype_name` *c;
-      const index_type m = xcount, n = ycount, k = count;
-
-      /* System generated locals */
-      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
-		 i1, i2, i3, i4, i5, i6;
-
-      /* Local variables */
-      'rtype_name` t1[65536], /* was [256][256] */
-		 f11, f12, f21, f22, f31, f32, f41, f42,
-		 f13, f14, f23, f24, f33, f34, f43, f44;
-      index_type i, j, l, ii, jj, ll;
-      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
-
-      a = abase;
-      b = bbase;
-      c = retarray->base_addr;
-
-      /* Parameter adjustments */
-      c_dim1 = rystride;
-      c_offset = 1 + c_dim1;
-      c -= c_offset;
-      a_dim1 = aystride;
-      a_offset = 1 + a_dim1;
-      a -= a_offset;
-      b_dim1 = bystride;
-      b_offset = 1 + b_dim1;
-      b -= b_offset;
-
-      /* Early exit if possible */
-      if (m == 0 || n == 0 || k == 0)
-	return;
-
-      /* Empty c first.  */
-      for (j=1; j<=n; j++)
-	for (i=1; i<=m; i++)
-	  c[i + j * c_dim1] = ('rtype_name`)0;
-
-      /* Start turning the crank. */
-      i1 = n;
-      for (jj = 1; jj <= i1; jj += 512)
+      matmul_p = matmul_'rtype_code`_vanilla;
+      if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
 	{
-	  /* Computing MIN */
-	  i2 = 512;
-	  i3 = n - jj + 1;
-	  jsec = min(i2,i3);
-	  ujsec = jsec - jsec % 4;
-	  i2 = k;
-	  for (ll = 1; ll <= i2; ll += 256)
+          /* Run down the available processors in order of preference.  */
+#ifdef HAVE_AVX512F
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
 	    {
-	      /* Computing MIN */
-	      i3 = 256;
-	      i4 = k - ll + 1;
-	      lsec = min(i3,i4);
-	      ulsec = lsec - lsec % 2;
-
-	      i3 = m;
-	      for (ii = 1; ii <= i3; ii += 256)
-		{
-		  /* Computing MIN */
-		  i4 = 256;
-		  i5 = m - ii + 1;
-		  isec = min(i4,i5);
-		  uisec = isec - isec % 2;
-		  i4 = ll + ulsec - 1;
-		  for (l = ll; l <= i4; l += 2)
-		    {
-		      i5 = ii + uisec - 1;
-		      for (i = ii; i <= i5; i += 2)
-			{
-			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
-					a[i + l * a_dim1];
-			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
-					a[i + (l + 1) * a_dim1];
-			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
-					a[i + 1 + l * a_dim1];
-			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
-					a[i + 1 + (l + 1) * a_dim1];
-			}
-		      if (uisec < isec)
-			{
-			  t1[l - ll + 1 + (isec << 8) - 257] =
-				    a[ii + isec - 1 + l * a_dim1];
-			  t1[l - ll + 2 + (isec << 8) - 257] =
-				    a[ii + isec - 1 + (l + 1) * a_dim1];
-			}
-		    }
-		  if (ulsec < lsec)
-		    {
-		      i4 = ii + isec - 1;
-		      for (i = ii; i<= i4; ++i)
-			{
-			  t1[lsec + ((i - ii + 1) << 8) - 257] =
-				    a[i + (ll + lsec - 1) * a_dim1];
-			}
-		    }
-
-		  uisec = isec - isec % 4;
-		  i4 = jj + ujsec - 1;
-		  for (j = jj; j <= i4; j += 4)
-		    {
-		      i5 = ii + uisec - 1;
-		      for (i = ii; i <= i5; i += 4)
-			{
-			  f11 = c[i + j * c_dim1];
-			  f21 = c[i + 1 + j * c_dim1];
-			  f12 = c[i + (j + 1) * c_dim1];
-			  f22 = c[i + 1 + (j + 1) * c_dim1];
-			  f13 = c[i + (j + 2) * c_dim1];
-			  f23 = c[i + 1 + (j + 2) * c_dim1];
-			  f14 = c[i + (j + 3) * c_dim1];
-			  f24 = c[i + 1 + (j + 3) * c_dim1];
-			  f31 = c[i + 2 + j * c_dim1];
-			  f41 = c[i + 3 + j * c_dim1];
-			  f32 = c[i + 2 + (j + 1) * c_dim1];
-			  f42 = c[i + 3 + (j + 1) * c_dim1];
-			  f33 = c[i + 2 + (j + 2) * c_dim1];
-			  f43 = c[i + 3 + (j + 2) * c_dim1];
-			  f34 = c[i + 2 + (j + 3) * c_dim1];
-			  f44 = c[i + 3 + (j + 3) * c_dim1];
-			  i6 = ll + lsec - 1;
-			  for (l = ll; l <= i6; ++l)
-			    {
-			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
-				      * b[l + j * b_dim1];
-			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
-				      * b[l + j * b_dim1];
-			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
-				      * b[l + (j + 1) * b_dim1];
-			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
-				      * b[l + (j + 1) * b_dim1];
-			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
-				      * b[l + (j + 2) * b_dim1];
-			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
-				      * b[l + (j + 2) * b_dim1];
-			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
-				      * b[l + (j + 3) * b_dim1];
-			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
-				      * b[l + (j + 3) * b_dim1];
-			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
-				      * b[l + j * b_dim1];
-			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
-				      * b[l + j * b_dim1];
-			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
-				      * b[l + (j + 1) * b_dim1];
-			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
-				      * b[l + (j + 1) * b_dim1];
-			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
-				      * b[l + (j + 2) * b_dim1];
-			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
-				      * b[l + (j + 2) * b_dim1];
-			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
-				      * b[l + (j + 3) * b_dim1];
-			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
-				      * b[l + (j + 3) * b_dim1];
-			    }
-			  c[i + j * c_dim1] = f11;
-			  c[i + 1 + j * c_dim1] = f21;
-			  c[i + (j + 1) * c_dim1] = f12;
-			  c[i + 1 + (j + 1) * c_dim1] = f22;
-			  c[i + (j + 2) * c_dim1] = f13;
-			  c[i + 1 + (j + 2) * c_dim1] = f23;
-			  c[i + (j + 3) * c_dim1] = f14;
-			  c[i + 1 + (j + 3) * c_dim1] = f24;
-			  c[i + 2 + j * c_dim1] = f31;
-			  c[i + 3 + j * c_dim1] = f41;
-			  c[i + 2 + (j + 1) * c_dim1] = f32;
-			  c[i + 3 + (j + 1) * c_dim1] = f42;
-			  c[i + 2 + (j + 2) * c_dim1] = f33;
-			  c[i + 3 + (j + 2) * c_dim1] = f43;
-			  c[i + 2 + (j + 3) * c_dim1] = f34;
-			  c[i + 3 + (j + 3) * c_dim1] = f44;
-			}
-		      if (uisec < isec)
-			{
-			  i5 = ii + isec - 1;
-			  for (i = ii + uisec; i <= i5; ++i)
-			    {
-			      f11 = c[i + j * c_dim1];
-			      f12 = c[i + (j + 1) * c_dim1];
-			      f13 = c[i + (j + 2) * c_dim1];
-			      f14 = c[i + (j + 3) * c_dim1];
-			      i6 = ll + lsec - 1;
-			      for (l = ll; l <= i6; ++l)
-				{
-				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
-					  257] * b[l + j * b_dim1];
-				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
-					  257] * b[l + (j + 1) * b_dim1];
-				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
-					  257] * b[l + (j + 2) * b_dim1];
-				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
-					  257] * b[l + (j + 3) * b_dim1];
-				}
-			      c[i + j * c_dim1] = f11;
-			      c[i + (j + 1) * c_dim1] = f12;
-			      c[i + (j + 2) * c_dim1] = f13;
-			      c[i + (j + 3) * c_dim1] = f14;
-			    }
-			}
-		    }
-		  if (ujsec < jsec)
-		    {
-		      i4 = jj + jsec - 1;
-		      for (j = jj + ujsec; j <= i4; ++j)
-			{
-			  i5 = ii + uisec - 1;
-			  for (i = ii; i <= i5; i += 4)
-			    {
-			      f11 = c[i + j * c_dim1];
-			      f21 = c[i + 1 + j * c_dim1];
-			      f31 = c[i + 2 + j * c_dim1];
-			      f41 = c[i + 3 + j * c_dim1];
-			      i6 = ll + lsec - 1;
-			      for (l = ll; l <= i6; ++l)
-				{
-				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
-					  257] * b[l + j * b_dim1];
-				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
-					  257] * b[l + j * b_dim1];
-				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
-					  257] * b[l + j * b_dim1];
-				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
-					  257] * b[l + j * b_dim1];
-				}
-			      c[i + j * c_dim1] = f11;
-			      c[i + 1 + j * c_dim1] = f21;
-			      c[i + 2 + j * c_dim1] = f31;
-			      c[i + 3 + j * c_dim1] = f41;
-			    }
-			  i5 = ii + isec - 1;
-			  for (i = ii + uisec; i <= i5; ++i)
-			    {
-			      f11 = c[i + j * c_dim1];
-			      i6 = ll + lsec - 1;
-			      for (l = ll; l <= i6; ++l)
-				{
-				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
-					  257] * b[l + j * b_dim1];
-				}
-			      c[i + j * c_dim1] = f11;
-			    }
-			}
-		    }
-		}
+	      matmul_p = matmul_'rtype_code`_avx512f;
+	      goto tailcall;
 	    }
-	}
-      return;
-    }
-  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
-    {
-      if (GFC_DESCRIPTOR_RANK (a) != 1)
-	{
-	  const 'rtype_name` *restrict abase_x;
-	  const 'rtype_name` *restrict bbase_y;
-	  'rtype_name` *restrict dest_y;
-	  'rtype_name` s;
 
-	  for (y = 0; y < ycount; y++)
-	    {
-	      bbase_y = &bbase[y*bystride];
-	      dest_y = &dest[y*rystride];
-	      for (x = 0; x < xcount; x++)
-		{
-		  abase_x = &abase[x*axstride];
-		  s = ('rtype_name`) 0;
-		  for (n = 0; n < count; n++)
-		    s += abase_x[n] * bbase_y[n];
-		  dest_y[x] = s;
-		}
-	    }
-	}
-      else
-	{
-	  const 'rtype_name` *restrict bbase_y;
-	  'rtype_name` s;
+#endif  /* HAVE_AVX512F */
 
-	  for (y = 0; y < ycount; y++)
+#ifdef HAVE_AVX2
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
 	    {
-	      bbase_y = &bbase[y*bystride];
-	      s = ('rtype_name`) 0;
-	      for (n = 0; n < count; n++)
-		s += abase[n*axstride] * bbase_y[n];
-	      dest[y*rystride] = s;
+	      matmul_p = matmul_'rtype_code`_avx2;
+	      goto tailcall;
 	    }
-	}
-    }
-  else if (axstride < aystride)
-    {
-      for (y = 0; y < ycount; y++)
-	for (x = 0; x < xcount; x++)
-	  dest[x*rxstride + y*rystride] = ('rtype_name`)0;
-
-      for (y = 0; y < ycount; y++)
-	for (n = 0; n < count; n++)
-	  for (x = 0; x < xcount; x++)
-	    /* dest[x,y] += a[x,n] * b[n,y] */
-	    dest[x*rxstride + y*rystride] +=
-					abase[x*axstride + n*aystride] *
-					bbase[n*bxstride + y*bystride];
-    }
-  else if (GFC_DESCRIPTOR_RANK (a) == 1)
-    {
-      const 'rtype_name` *restrict bbase_y;
-      'rtype_name` s;
 
-      for (y = 0; y < ycount; y++)
-	{
-	  bbase_y = &bbase[y*bystride];
-	  s = ('rtype_name`) 0;
-	  for (n = 0; n < count; n++)
-	    s += abase[n*axstride] * bbase_y[n*bxstride];
-	  dest[y*rxstride] = s;
-	}
-    }
-  else
-    {
-      const 'rtype_name` *restrict abase_x;
-      const 'rtype_name` *restrict bbase_y;
-      'rtype_name` *restrict dest_y;
-      'rtype_name` s;
+#endif
 
-      for (y = 0; y < ycount; y++)
-	{
-	  bbase_y = &bbase[y*bystride];
-	  dest_y = &dest[y*rystride];
-	  for (x = 0; x < xcount; x++)
-	    {
-	      abase_x = &abase[x*axstride];
-	      s = ('rtype_name`) 0;
-	      for (n = 0; n < count; n++)
-		s += abase_x[n*aystride] * bbase_y[n*bxstride];
-	      dest_y[x*rxstride] = s;
+#ifdef HAVE_AVX
+      	  if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
+ 	    {
+              matmul_p = matmul_'rtype_code`_avx;
+	      goto tailcall;
 	    }
-	}
-    }
-}'
+#endif  /* HAVE_AVX */
+        }
+   }
+
+tailcall:
+   (*matmul_p) (retarray, a, b, try_blas, blas_limit, gemm);
+}
+
+#else  /* Just the vanilla function.  */
+
+'define(`matmul_name',`matmul_'rtype_code)dnl
+define(`target_attribute',`')dnl
+include(matmul_internal.m4)dnl
+`#endif
 #endif
+'
diff --git a/libgfortran/m4/matmul_internal.m4 b/libgfortran/m4/matmul_internal.m4
new file mode 100644
index 00000000000..d35968b3be5
--- /dev/null
+++ b/libgfortran/m4/matmul_internal.m4
@@ -0,0 +1,537 @@
+`void
+'matmul_name` ('rtype` * const restrict retarray, 
+	'rtype` * const restrict a, 'rtype` * const restrict b, int try_blas,
+	int blas_limit, blas_call gemm)
+{
+  const 'rtype_name` * restrict abase;
+  const 'rtype_name` * restrict bbase;
+  'rtype_name` * restrict dest;
+
+  index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
+  index_type x, y, n, count, xcount, ycount;
+
+  assert (GFC_DESCRIPTOR_RANK (a) == 2
+          || GFC_DESCRIPTOR_RANK (b) == 2);
+
+/* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
+
+   Either A or B (but not both) can be rank 1:
+
+   o One-dimensional argument A is implicitly treated as a row matrix
+     dimensioned [1,count], so xcount=1.
+
+   o One-dimensional argument B is implicitly treated as a column matrix
+     dimensioned [count, 1], so ycount=1.
+*/
+
+  if (retarray->base_addr == NULL)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
+        }
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+        }
+      else
+        {
+	  GFC_DIMENSION_SET(retarray->dim[0], 0,
+	                    GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
+
+          GFC_DIMENSION_SET(retarray->dim[1], 0,
+	                    GFC_DESCRIPTOR_EXTENT(b,1) - 1,
+			    GFC_DESCRIPTOR_EXTENT(retarray,0));
+        }
+
+      retarray->base_addr
+	= xmallocarray (size0 ((array_t *) retarray), sizeof ('rtype_name`));
+      retarray->offset = 0;
+    }
+  else if (unlikely (compile_options.bounds_check))
+    {
+      index_type ret_extent, arg_extent;
+
+      if (GFC_DESCRIPTOR_RANK (a) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else if (GFC_DESCRIPTOR_RANK (b) == 1)
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic: is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+      else
+	{
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 1:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+
+	  arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
+	  ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
+	  if (arg_extent != ret_extent)
+	    runtime_error ("Incorrect extent in return array in"
+			   " MATMUL intrinsic for dimension 2:"
+			   " is %ld, should be %ld",
+			   (long int) ret_extent, (long int) arg_extent);
+	}
+    }
+'
+sinclude(`matmul_asm_'rtype_code`.m4')dnl
+`
+  if (GFC_DESCRIPTOR_RANK (retarray) == 1)
+    {
+      /* One-dimensional result may be addressed in the code below
+	 either as a row or a column matrix. We want both cases to
+	 work. */
+      rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+    }
+  else
+    {
+      rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
+      rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
+    }
+
+
+  if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      /* Treat it as a a row matrix A[1,count]. */
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = 1;
+
+      xcount = 1;
+      count = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+  else
+    {
+      axstride = GFC_DESCRIPTOR_STRIDE(a,0);
+      aystride = GFC_DESCRIPTOR_STRIDE(a,1);
+
+      count = GFC_DESCRIPTOR_EXTENT(a,1);
+      xcount = GFC_DESCRIPTOR_EXTENT(a,0);
+    }
+
+  if (count != GFC_DESCRIPTOR_EXTENT(b,0))
+    {
+      if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
+	runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
+    }
+
+  if (GFC_DESCRIPTOR_RANK (b) == 1)
+    {
+      /* Treat it as a column matrix B[count,1] */
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+
+      /* bystride should never be used for 1-dimensional b.
+	 in case it is we want it to cause a segfault, rather than
+	 an incorrect result. */
+      bystride = 0xDEADBEEF;
+      ycount = 1;
+    }
+  else
+    {
+      bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
+      bystride = GFC_DESCRIPTOR_STRIDE(b,1);
+      ycount = GFC_DESCRIPTOR_EXTENT(b,1);
+    }
+
+  abase = a->base_addr;
+  bbase = b->base_addr;
+  dest = retarray->base_addr;
+
+  /* Now that everything is set up, we perform the multiplication
+     itself.  */
+
+#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
+#define min(a,b) ((a) <= (b) ? (a) : (b))
+#define max(a,b) ((a) >= (b) ? (a) : (b))
+
+  if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
+      && (bxstride == 1 || bystride == 1)
+      && (((float) xcount) * ((float) ycount) * ((float) count)
+          > POW3(blas_limit)))
+    {
+      const int m = xcount, n = ycount, k = count, ldc = rystride;
+      const 'rtype_name` one = 1, zero = 0;
+      const int lda = (axstride == 1) ? aystride : axstride,
+		ldb = (bxstride == 1) ? bystride : bxstride;
+
+      if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
+	{
+	  assert (gemm != NULL);
+	  gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
+		&n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
+		&ldc, 1, 1);
+	  return;
+	}
+    }
+
+  if (rxstride == 1 && axstride == 1 && bxstride == 1)
+    {
+      /* This block of code implements a tuned matmul, derived from
+         Superscalar GEMM-based level 3 BLAS,  Beta version 0.1
+
+               Bo Kagstrom and Per Ling
+               Department of Computing Science
+               Umea University
+               S-901 87 Umea, Sweden
+
+	 from netlib.org, translated to C, and modified for matmul.m4.  */
+
+      const 'rtype_name` *a, *b;
+      'rtype_name` *c;
+      const index_type m = xcount, n = ycount, k = count;
+
+      /* System generated locals */
+      index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
+		 i1, i2, i3, i4, i5, i6;
+
+      /* Local variables */
+      'rtype_name` t1[65536], /* was [256][256] */
+		 f11, f12, f21, f22, f31, f32, f41, f42,
+		 f13, f14, f23, f24, f33, f34, f43, f44;
+      index_type i, j, l, ii, jj, ll;
+      index_type isec, jsec, lsec, uisec, ujsec, ulsec;
+
+      a = abase;
+      b = bbase;
+      c = retarray->base_addr;
+
+      /* Parameter adjustments */
+      c_dim1 = rystride;
+      c_offset = 1 + c_dim1;
+      c -= c_offset;
+      a_dim1 = aystride;
+      a_offset = 1 + a_dim1;
+      a -= a_offset;
+      b_dim1 = bystride;
+      b_offset = 1 + b_dim1;
+      b -= b_offset;
+
+      /* Early exit if possible */
+      if (m == 0 || n == 0 || k == 0)
+	return;
+
+      /* Empty c first.  */
+      for (j=1; j<=n; j++)
+	for (i=1; i<=m; i++)
+	  c[i + j * c_dim1] = ('rtype_name`)0;
+
+      /* Start turning the crank. */
+      i1 = n;
+      for (jj = 1; jj <= i1; jj += 512)
+	{
+	  /* Computing MIN */
+	  i2 = 512;
+	  i3 = n - jj + 1;
+	  jsec = min(i2,i3);
+	  ujsec = jsec - jsec % 4;
+	  i2 = k;
+	  for (ll = 1; ll <= i2; ll += 256)
+	    {
+	      /* Computing MIN */
+	      i3 = 256;
+	      i4 = k - ll + 1;
+	      lsec = min(i3,i4);
+	      ulsec = lsec - lsec % 2;
+
+	      i3 = m;
+	      for (ii = 1; ii <= i3; ii += 256)
+		{
+		  /* Computing MIN */
+		  i4 = 256;
+		  i5 = m - ii + 1;
+		  isec = min(i4,i5);
+		  uisec = isec - isec % 2;
+		  i4 = ll + ulsec - 1;
+		  for (l = ll; l <= i4; l += 2)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 2)
+			{
+			  t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
+					a[i + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
+					a[i + (l + 1) * a_dim1];
+			  t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + l * a_dim1];
+			  t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
+					a[i + 1 + (l + 1) * a_dim1];
+			}
+		      if (uisec < isec)
+			{
+			  t1[l - ll + 1 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + l * a_dim1];
+			  t1[l - ll + 2 + (isec << 8) - 257] =
+				    a[ii + isec - 1 + (l + 1) * a_dim1];
+			}
+		    }
+		  if (ulsec < lsec)
+		    {
+		      i4 = ii + isec - 1;
+		      for (i = ii; i<= i4; ++i)
+			{
+			  t1[lsec + ((i - ii + 1) << 8) - 257] =
+				    a[i + (ll + lsec - 1) * a_dim1];
+			}
+		    }
+
+		  uisec = isec - isec % 4;
+		  i4 = jj + ujsec - 1;
+		  for (j = jj; j <= i4; j += 4)
+		    {
+		      i5 = ii + uisec - 1;
+		      for (i = ii; i <= i5; i += 4)
+			{
+			  f11 = c[i + j * c_dim1];
+			  f21 = c[i + 1 + j * c_dim1];
+			  f12 = c[i + (j + 1) * c_dim1];
+			  f22 = c[i + 1 + (j + 1) * c_dim1];
+			  f13 = c[i + (j + 2) * c_dim1];
+			  f23 = c[i + 1 + (j + 2) * c_dim1];
+			  f14 = c[i + (j + 3) * c_dim1];
+			  f24 = c[i + 1 + (j + 3) * c_dim1];
+			  f31 = c[i + 2 + j * c_dim1];
+			  f41 = c[i + 3 + j * c_dim1];
+			  f32 = c[i + 2 + (j + 1) * c_dim1];
+			  f42 = c[i + 3 + (j + 1) * c_dim1];
+			  f33 = c[i + 2 + (j + 2) * c_dim1];
+			  f43 = c[i + 3 + (j + 2) * c_dim1];
+			  f34 = c[i + 2 + (j + 3) * c_dim1];
+			  f44 = c[i + 3 + (j + 3) * c_dim1];
+			  i6 = ll + lsec - 1;
+			  for (l = ll; l <= i6; ++l)
+			    {
+			      f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + j * b_dim1];
+			      f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 1) * b_dim1];
+			      f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 2) * b_dim1];
+			      f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			      f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
+				      * b[l + (j + 3) * b_dim1];
+			    }
+			  c[i + j * c_dim1] = f11;
+			  c[i + 1 + j * c_dim1] = f21;
+			  c[i + (j + 1) * c_dim1] = f12;
+			  c[i + 1 + (j + 1) * c_dim1] = f22;
+			  c[i + (j + 2) * c_dim1] = f13;
+			  c[i + 1 + (j + 2) * c_dim1] = f23;
+			  c[i + (j + 3) * c_dim1] = f14;
+			  c[i + 1 + (j + 3) * c_dim1] = f24;
+			  c[i + 2 + j * c_dim1] = f31;
+			  c[i + 3 + j * c_dim1] = f41;
+			  c[i + 2 + (j + 1) * c_dim1] = f32;
+			  c[i + 3 + (j + 1) * c_dim1] = f42;
+			  c[i + 2 + (j + 2) * c_dim1] = f33;
+			  c[i + 3 + (j + 2) * c_dim1] = f43;
+			  c[i + 2 + (j + 3) * c_dim1] = f34;
+			  c[i + 3 + (j + 3) * c_dim1] = f44;
+			}
+		      if (uisec < isec)
+			{
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f12 = c[i + (j + 1) * c_dim1];
+			      f13 = c[i + (j + 2) * c_dim1];
+			      f14 = c[i + (j + 3) * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 1) * b_dim1];
+				  f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 2) * b_dim1];
+				  f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + (j + 3) * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + (j + 1) * c_dim1] = f12;
+			      c[i + (j + 2) * c_dim1] = f13;
+			      c[i + (j + 3) * c_dim1] = f14;
+			    }
+			}
+		    }
+		  if (ujsec < jsec)
+		    {
+		      i4 = jj + jsec - 1;
+		      for (j = jj + ujsec; j <= i4; ++j)
+			{
+			  i5 = ii + uisec - 1;
+			  for (i = ii; i <= i5; i += 4)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      f21 = c[i + 1 + j * c_dim1];
+			      f31 = c[i + 2 + j * c_dim1];
+			      f41 = c[i + 3 + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
+					  257] * b[l + j * b_dim1];
+				  f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			      c[i + 1 + j * c_dim1] = f21;
+			      c[i + 2 + j * c_dim1] = f31;
+			      c[i + 3 + j * c_dim1] = f41;
+			    }
+			  i5 = ii + isec - 1;
+			  for (i = ii + uisec; i <= i5; ++i)
+			    {
+			      f11 = c[i + j * c_dim1];
+			      i6 = ll + lsec - 1;
+			      for (l = ll; l <= i6; ++l)
+				{
+				  f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
+					  257] * b[l + j * b_dim1];
+				}
+			      c[i + j * c_dim1] = f11;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+      return;
+    }
+  else if (rxstride == 1 && aystride == 1 && bxstride == 1)
+    {
+      if (GFC_DESCRIPTOR_RANK (a) != 1)
+	{
+	  const 'rtype_name` *restrict abase_x;
+	  const 'rtype_name` *restrict bbase_y;
+	  'rtype_name` *restrict dest_y;
+	  'rtype_name` s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      dest_y = &dest[y*rystride];
+	      for (x = 0; x < xcount; x++)
+		{
+		  abase_x = &abase[x*axstride];
+		  s = ('rtype_name`) 0;
+		  for (n = 0; n < count; n++)
+		    s += abase_x[n] * bbase_y[n];
+		  dest_y[x] = s;
+		}
+	    }
+	}
+      else
+	{
+	  const 'rtype_name` *restrict bbase_y;
+	  'rtype_name` s;
+
+	  for (y = 0; y < ycount; y++)
+	    {
+	      bbase_y = &bbase[y*bystride];
+	      s = ('rtype_name`) 0;
+	      for (n = 0; n < count; n++)
+		s += abase[n*axstride] * bbase_y[n];
+	      dest[y*rystride] = s;
+	    }
+	}
+    }
+  else if (axstride < aystride)
+    {
+      for (y = 0; y < ycount; y++)
+	for (x = 0; x < xcount; x++)
+	  dest[x*rxstride + y*rystride] = ('rtype_name`)0;
+
+      for (y = 0; y < ycount; y++)
+	for (n = 0; n < count; n++)
+	  for (x = 0; x < xcount; x++)
+	    /* dest[x,y] += a[x,n] * b[n,y] */
+	    dest[x*rxstride + y*rystride] +=
+					abase[x*axstride + n*aystride] *
+					bbase[n*bxstride + y*bystride];
+    }
+  else if (GFC_DESCRIPTOR_RANK (a) == 1)
+    {
+      const 'rtype_name` *restrict bbase_y;
+      'rtype_name` s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  s = ('rtype_name`) 0;
+	  for (n = 0; n < count; n++)
+	    s += abase[n*axstride] * bbase_y[n*bxstride];
+	  dest[y*rxstride] = s;
+	}
+    }
+  else
+    {
+      const 'rtype_name` *restrict abase_x;
+      const 'rtype_name` *restrict bbase_y;
+      'rtype_name` *restrict dest_y;
+      'rtype_name` s;
+
+      for (y = 0; y < ycount; y++)
+	{
+	  bbase_y = &bbase[y*bystride];
+	  dest_y = &dest[y*rystride];
+	  for (x = 0; x < xcount; x++)
+	    {
+	      abase_x = &abase[x*axstride];
+	      s = ('rtype_name`) 0;
+	      for (n = 0; n < count; n++)
+		s += abase_x[n*aystride] * bbase_y[n*bxstride];
+	      dest_y[x*rxstride] = s;
+	    }
+	}
+    }
+}
+#undef POW3
+#undef min
+#undef max
+'