re PR fortran/36313 ([F03] {MIN,MAX}{LOC,VAL} should accept character arguments)

2017-12-03  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/36313
	* check.c (gfc_check_minval_maxval): Use
	int_orLreal_or_char_check_f2003 for array argument.
	* iresolve.c (gfc_resolve_maxval): Insert number in
	function name for character arguments.
	(gfc_resolve_minval): Likewise.
	* trans-intrinsic.c (gfc_conv_intrinsic_minmaxloc):
	Fix comment.
	(gfc_conv_intrinsic_minmaxval): Resort arguments and call library
	function if dealing with a character function.

2017-12-03  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/36313
	* Makefile.am: Add new files for character-valued
	maxval and minval.
	* Makefile.in: Regenerated.
	* gfortran.map: Add new functions.
	* m4/iforeach-s2.m4: New file.
	* m4/ifunction-s2.m4: New file.
	* m4/iparm.m4: Add intitval for minval and maxval.
	* m4/maxval0s.m4: New file.
	* m4/maxval1s.m4: New file.
	* m4/minval0s.m4: New file.
	* m4/minval1s.m4: New file.
        * generated/maxval0_s1.c: New file.
        * generated/maxval0_s4.c: New file.
        * generated/maxval1_s1.c: New file.
        * generated/maxval1_s4.c: New file.
        * generated/minval0_s1.c: New file.
        * generated/minval0_s4.c: New file.
        * generated/minval1_s1.c: New file.
        * generated/minval1_s4.c: New file.

2017-12-03  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/36313
	* gfortran.dg/maxval_char_1.f90: New test.
	* gfortran.dg/maxval_char_2.f90: New test.
	* gfortran.dg/maxval_char_3.f90: New test.
	* gfortran.dg/maxval_char_4.f90: New test.
	* gfortran.dg/minval_char_1.f90: New test.
	* gfortran.dg/minval_char_2.f90: New test.
	* gfortran.dg/minval_char_3.f90: New test.
	* gfortran.dg/minval_char_4.f90: New test.

From-SVN: r255367

7 files changed, 1003 insertions, 0 deletions

diff --git a/libgfortran/m4/iforeach-s2.m4 b/libgfortran/m4/iforeach-s2.m4
new file mode 100644
index 00000000000..19d016f7c65
--- /dev/null
+++ b/libgfortran/m4/iforeach-s2.m4
@@ -0,0 +1,222 @@
+dnl Support macro file for intrinsic functions.
+dnl Contains the generic sections of the array functions.
+dnl This file is part of the GNU Fortran Runtime Library (libgfortran)
+dnl Distributed under the GNU GPL with exception.  See COPYING for details.
+define(START_FOREACH_FUNCTION,
+`static inline int
+compare_fcn (const atype_name *a, const atype_name *b, gfc_charlen_type n)
+{
+  if (sizeof ('atype_name`) == 1)
+    return memcmp (a, b, n);
+  else
+    return memcmp_char4 (a, b, n);
+
+}
+
+#define INITVAL 'initval`
+
+extern void 'name`'rtype_qual`_'atype_code (atype_name * restrict,
+        gfc_charlen_type,
+	atype * const restrict array, gfc_charlen_type);
+export_proto(name`'rtype_qual`_'atype_code);
+
+void
+name`'rtype_qual`_'atype_code` ('atype_name` * restrict ret,
+        gfc_charlen_type xlen,
+	'atype` * const restrict array, gfc_charlen_type len)
+{
+  index_type count[GFC_MAX_DIMENSIONS];
+  index_type extent[GFC_MAX_DIMENSIONS];
+  index_type sstride[GFC_MAX_DIMENSIONS];
+  const 'atype_name` *base;
+  index_type rank;
+  index_type n;
+
+  rank = GFC_DESCRIPTOR_RANK (array);
+  if (rank <= 0)
+    runtime_error ("Rank of array needs to be > 0");
+
+  assert (xlen == len);
+
+  /* Initialize return value.  */
+  memset (ret, INITVAL, sizeof(*ret) * len);
+
+  for (n = 0; n < rank; n++)
+    {
+      sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n) * len;
+      extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
+      count[n] = 0;
+      if (extent[n] <= 0)
+        return;
+    }
+
+  base = array->base_addr;
+
+  {
+')dnl
+define(START_FOREACH_BLOCK,
+`  while (base)
+    {
+      do
+	{
+	  /* Implementation start.  */
+')dnl
+define(FINISH_FOREACH_FUNCTION,
+`	  /* Implementation end.  */
+	  /* Advance to the next element.  */
+	  base += sstride[0];
+	}
+      while (++count[0] != extent[0]);
+      n = 0;
+      do
+	{
+	  /* When we get to the end of a dimension, reset it and increment
+	     the next dimension.  */
+	  count[n] = 0;
+	  /* We could precalculate these products, but this is a less
+	     frequently used path so probably not worth it.  */
+	  base -= sstride[n] * extent[n];
+	  n++;
+	  if (n >= rank)
+	    {
+	      /* Break out of the loop.  */
+	      base = NULL;
+	      break;
+	    }
+	  else
+	    {
+	      count[n]++;
+	      base += sstride[n];
+	    }
+	}
+      while (count[n] == extent[n]);
+    }
+   memcpy (ret, retval, len * sizeof (*ret));
+  }
+}')dnl
+define(START_MASKED_FOREACH_FUNCTION,
+`
+extern void `m'name`'rtype_qual`_'atype_code (atype_name * restrict,
+       gfc_charlen_type, atype * const restrict array,
+       gfc_array_l1 * const restrict mask, gfc_charlen_type len);
+export_proto(`m'name`'rtype_qual`_'atype_code);
+
+void
+`m'name`'rtype_qual`_'atype_code (atype_name * const restrict ret,
+	gfc_charlen_type xlen, atype * const restrict array,
+	gfc_array_l1 * const restrict mask, gfc_charlen_type len)
+{
+  index_type count[GFC_MAX_DIMENSIONS];
+  index_type extent[GFC_MAX_DIMENSIONS];
+  index_type sstride[GFC_MAX_DIMENSIONS];
+  index_type mstride[GFC_MAX_DIMENSIONS];
+  const atype_name *base;
+  GFC_LOGICAL_1 *mbase;
+  int rank;
+  index_type n;
+  int mask_kind;
+
+  rank = GFC_DESCRIPTOR_RANK (array);
+  if (rank <= 0)
+    runtime_error ("Rank of array needs to be > 0");
+
+  assert (xlen == len);
+
+/* Initialize return value.  */
+  memset (ret, INITVAL, sizeof(*ret) * len);
+
+  mask_kind = GFC_DESCRIPTOR_SIZE (mask);
+
+  mbase = mask->base_addr;
+
+  if (mask_kind == 1 || mask_kind == 2 || mask_kind == 4 || mask_kind == 8
+#ifdef HAVE_GFC_LOGICAL_16
+      || mask_kind == 16
+#endif
+      )
+    mbase = GFOR_POINTER_TO_L1 (mbase, mask_kind);
+  else
+    runtime_error ("Funny sized logical array");
+
+  for (n = 0; n < rank; n++)
+    {
+      sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n) * len;
+      mstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(mask,n);
+      extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
+      count[n] = 0;
+      if (extent[n] <= 0)
+	return;
+    }
+
+  base = array->base_addr;
+  {
+')dnl
+define(START_MASKED_FOREACH_BLOCK, `START_FOREACH_BLOCK')dnl
+define(FINISH_MASKED_FOREACH_FUNCTION,
+`	  /* Implementation end.  */
+	  /* Advance to the next element.  */
+	  base += sstride[0];
+	  mbase += mstride[0];
+	}
+      while (++count[0] != extent[0]);
+      n = 0;
+      do
+	{
+	  /* When we get to the end of a dimension, reset it and increment
+	     the next dimension.  */
+	  count[n] = 0;
+	  /* We could precalculate these products, but this is a less
+	     frequently used path so probably not worth it.  */
+	  base -= sstride[n] * extent[n];
+	  mbase -= mstride[n] * extent[n];
+	  n++;
+	  if (n >= rank)
+	    {
+	      /* Break out of the loop.  */
+	      base = NULL;
+	      break;
+	    }
+	  else
+	    {
+	      count[n]++;
+	      base += sstride[n];
+	      mbase += mstride[n];
+	    }
+	}
+      while (count[n] == extent[n]);
+    }
+    memcpy (ret, retval, len * sizeof (*ret));
+  }
+}')dnl
+define(FOREACH_FUNCTION,
+`START_FOREACH_FUNCTION
+$1
+START_FOREACH_BLOCK
+$2
+FINISH_FOREACH_FUNCTION')dnl
+define(MASKED_FOREACH_FUNCTION,
+`START_MASKED_FOREACH_FUNCTION
+$1
+START_MASKED_FOREACH_BLOCK
+$2
+FINISH_MASKED_FOREACH_FUNCTION')dnl
+define(SCALAR_FOREACH_FUNCTION,
+`
+extern void `s'name`'rtype_qual`_'atype_code (atype_name * restrict,
+        gfc_charlen_type,
+	atype * const restrict array, GFC_LOGICAL_4 *, gfc_charlen_type);
+export_proto(`s'name`'rtype_qual`_'atype_code);
+
+void
+`s'name`'rtype_qual`_'atype_code (atype_name * restrict ret,
+        gfc_charlen_type xlen, atype * const restrict array,
+	GFC_LOGICAL_4 *mask, gfc_charlen_type len)
+	
+{
+  if (*mask)
+    {
+      name`'rtype_qual`_'atype_code (ret, xlen, array, len);
+      return;
+    }
+  memset (ret, INITVAL, sizeof (*ret) * len);
+}')dnl
diff --git a/libgfortran/m4/ifunction-s2.m4 b/libgfortran/m4/ifunction-s2.m4
new file mode 100644
index 00000000000..4eb09084dde
--- /dev/null
+++ b/libgfortran/m4/ifunction-s2.m4
@@ -0,0 +1,542 @@
+dnl Support macro file for intrinsic functions.
+dnl Contains the generic sections of the array functions.
+dnl This file is part of the GNU Fortran Runtime Library (libgfortran)
+dnl Distributed under the GNU GPL with exception.  See COPYING for details.
+dnl
+dnl Pass the implementation for a single section as the parameter to
+dnl {MASK_}ARRAY_FUNCTION.
+dnl The variables base, delta, and len describe the input section.
+dnl For masked section the mask is described by mbase and mdelta.
+dnl These should not be modified. The result should be stored in *dest.
+dnl The names count, extent, sstride, dstride, base, dest, rank, dim
+dnl retarray, array, pdim and mstride should not be used.
+dnl The variable n is declared as index_type and may be used.
+dnl Other variable declarations may be placed at the start of the code,
+dnl The types of the array parameter and the return value are
+dnl atype_name and rtype_name respectively.
+dnl Execution should be allowed to continue to the end of the block.
+dnl You should not return or break from the inner loop of the implementation.
+dnl Care should also be taken to avoid using the names defined in iparm.m4
+define(START_ARRAY_FUNCTION,
+`#include <string.h>
+#include <assert.h>
+
+static inline int
+compare_fcn (const atype_name *a, const atype_name *b, gfc_charlen_type n)
+{
+  if (sizeof ('atype_name`) == 1)
+    return memcmp (a, b, n);
+  else
+    return memcmp_char4 (a, b, n);
+}
+
+extern void name`'rtype_qual`_'atype_code (rtype * const restrict,
+        gfc_charlen_type, atype * const restrict,
+	const index_type * const restrict, gfc_charlen_type);
+export_proto(name`'rtype_qual`_'atype_code);
+
+void
+name`'rtype_qual`_'atype_code (rtype * const restrict retarray, 
+	gfc_charlen_type xlen, atype * const restrict array, 
+	const index_type * const restrict pdim, gfc_charlen_type string_len)
+{
+  index_type count[GFC_MAX_DIMENSIONS];
+  index_type extent[GFC_MAX_DIMENSIONS];
+  index_type sstride[GFC_MAX_DIMENSIONS];
+  index_type dstride[GFC_MAX_DIMENSIONS];
+  const atype_name * restrict base;
+  rtype_name * restrict dest;
+  index_type rank;
+  index_type n;
+  index_type len;
+  index_type delta;
+  index_type dim;
+  int continue_loop;
+
+  assert (xlen == string_len);
+  /* Make dim zero based to avoid confusion.  */
+  rank = GFC_DESCRIPTOR_RANK (array) - 1;
+  dim = (*pdim) - 1;
+
+  if (unlikely (dim < 0 || dim > rank))
+    {
+      runtime_error ("Dim argument incorrect in u_name intrinsic: "
+ 		     "is %ld, should be between 1 and %ld",
+		     (long int) dim + 1, (long int) rank + 1);
+    }
+
+  len = GFC_DESCRIPTOR_EXTENT(array,dim);
+  if (len < 0)
+    len = 0;
+
+  delta = GFC_DESCRIPTOR_STRIDE(array,dim) * string_len;
+
+  for (n = 0; n < dim; n++)
+    {
+      sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n) * string_len;
+      extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
+
+      if (extent[n] < 0)
+	extent[n] = 0;
+    }
+  for (n = dim; n < rank; n++)
+    {
+      sstride[n] = GFC_DESCRIPTOR_STRIDE(array, n + 1) * string_len;
+      extent[n] = GFC_DESCRIPTOR_EXTENT(array, n + 1);
+
+      if (extent[n] < 0)
+	extent[n] = 0;
+    }
+
+  if (retarray->base_addr == NULL)
+    {
+      size_t alloc_size, str;
+
+      for (n = 0; n < rank; n++)
+	{
+	  if (n == 0)
+	    str = 1;
+	  else
+	    str = GFC_DESCRIPTOR_STRIDE(retarray,n-1) * extent[n-1];
+
+	  GFC_DIMENSION_SET(retarray->dim[n], 0, extent[n] - 1, str);
+
+	}
+
+      retarray->offset = 0;
+      retarray->dtype = (array->dtype & ~GFC_DTYPE_RANK_MASK) | rank;
+
+      alloc_size = GFC_DESCRIPTOR_STRIDE(retarray,rank-1) * extent[rank-1]
+      		 * string_len;
+
+      retarray->base_addr = xmallocarray (alloc_size, sizeof (rtype_name));
+      if (alloc_size == 0)
+	{
+	  /* Make sure we have a zero-sized array.  */
+	  GFC_DIMENSION_SET(retarray->dim[0], 0, -1, 1);
+	  return;
+
+	}
+    }
+  else
+    {
+      if (rank != GFC_DESCRIPTOR_RANK (retarray))
+	runtime_error ("rank of return array incorrect in"
+		       " u_name intrinsic: is %ld, should be %ld",
+		       (long int) (GFC_DESCRIPTOR_RANK (retarray)),
+		       (long int) rank);
+
+      if (unlikely (compile_options.bounds_check))
+	bounds_ifunction_return ((array_t *) retarray, extent,
+				 "return value", "u_name");
+    }
+
+  for (n = 0; n < rank; n++)
+    {
+      count[n] = 0;
+      dstride[n] = GFC_DESCRIPTOR_STRIDE(retarray,n) * string_len;
+      if (extent[n] <= 0)
+	return;
+    }
+
+  base = array->base_addr;
+  dest = retarray->base_addr;
+
+  continue_loop = 1;
+  while (continue_loop)
+    {
+      const atype_name * restrict src;
+      src = base;
+      {
+')dnl
+define(START_ARRAY_BLOCK,
+`	if (len <= 0)
+	  memset (dest, '$1`, sizeof (*dest) * string_len);
+	else
+	  {
+	    for (n = 0; n < len; n++, src += delta)
+	      {
+')dnl
+define(FINISH_ARRAY_FUNCTION,
+`	      }
+	    '$1`
+	    memcpy (dest, retval, sizeof (*dest) * string_len);
+	  }
+      }
+      /* Advance to the next element.  */
+      count[0]++;
+      base += sstride[0];
+      dest += dstride[0];
+      n = 0;
+      while (count[n] == extent[n])
+	{
+	  /* When we get to the end of a dimension, reset it and increment
+	     the next dimension.  */
+	  count[n] = 0;
+	  /* We could precalculate these products, but this is a less
+	     frequently used path so probably not worth it.  */
+	  base -= sstride[n] * extent[n];
+	  dest -= dstride[n] * extent[n];
+	  n++;
+	  if (n >= rank)
+	    {
+	      /* Break out of the loop.  */
+	      continue_loop = 0;
+	      break;
+	    }
+	  else
+	    {
+	      count[n]++;
+	      base += sstride[n];
+	      dest += dstride[n];
+	    }
+	}
+    }
+}')dnl
+define(START_MASKED_ARRAY_FUNCTION,
+`
+extern void `m'name`'rtype_qual`_'atype_code (rtype * const restrict,
+        gfc_charlen_type, atype * const restrict,
+	const index_type * const restrict,
+	gfc_array_l1 * const restrict, gfc_charlen_type);
+export_proto(`m'name`'rtype_qual`_'atype_code);
+
+void
+`m'name`'rtype_qual`_'atype_code (rtype * const restrict retarray, 
+	gfc_charlen_type xlen, atype * const restrict array, 
+	const index_type * const restrict pdim,
+	gfc_array_l1 * const restrict mask,
+	gfc_charlen_type string_len)
+
+{
+  index_type count[GFC_MAX_DIMENSIONS];
+  index_type extent[GFC_MAX_DIMENSIONS];
+  index_type sstride[GFC_MAX_DIMENSIONS];
+  index_type dstride[GFC_MAX_DIMENSIONS];
+  index_type mstride[GFC_MAX_DIMENSIONS];
+  rtype_name * restrict dest;
+  const atype_name * restrict base;
+  const GFC_LOGICAL_1 * restrict mbase;
+  index_type rank;
+  index_type dim;
+  index_type n;
+  index_type len;
+  index_type delta;
+  index_type mdelta;
+  int mask_kind;
+
+  assert (xlen == string_len);
+
+  dim = (*pdim) - 1;
+  rank = GFC_DESCRIPTOR_RANK (array) - 1;
+
+  if (unlikely (dim < 0 || dim > rank))
+    {
+      runtime_error ("Dim argument incorrect in u_name intrinsic: "
+ 		     "is %ld, should be between 1 and %ld",
+		     (long int) dim + 1, (long int) rank + 1);
+    }
+
+  len = GFC_DESCRIPTOR_EXTENT(array,dim);
+  if (len <= 0)
+    return;
+
+  mbase = mask->base_addr;
+
+  mask_kind = GFC_DESCRIPTOR_SIZE (mask);
+
+  if (mask_kind == 1 || mask_kind == 2 || mask_kind == 4 || mask_kind == 8
+#ifdef HAVE_GFC_LOGICAL_16
+      || mask_kind == 16
+#endif
+      )
+    mbase = GFOR_POINTER_TO_L1 (mbase, mask_kind);
+  else
+    runtime_error ("Funny sized logical array");
+
+  delta = GFC_DESCRIPTOR_STRIDE(array,dim) * string_len;
+  mdelta = GFC_DESCRIPTOR_STRIDE_BYTES(mask,dim);
+
+  for (n = 0; n < dim; n++)
+    {
+      sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n) * string_len;
+      mstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(mask,n);
+      extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
+
+      if (extent[n] < 0)
+	extent[n] = 0;
+
+    }
+  for (n = dim; n < rank; n++)
+    {
+      sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n + 1) * string_len;
+      mstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(mask, n + 1);
+      extent[n] = GFC_DESCRIPTOR_EXTENT(array, n + 1);
+
+      if (extent[n] < 0)
+	extent[n] = 0;
+    }
+
+  if (retarray->base_addr == NULL)
+    {
+      size_t alloc_size, str;
+
+      for (n = 0; n < rank; n++)
+	{
+	  if (n == 0)
+	    str = 1;
+	  else
+	    str= GFC_DESCRIPTOR_STRIDE(retarray,n-1) * extent[n-1];
+
+	  GFC_DIMENSION_SET(retarray->dim[n], 0, extent[n] - 1, str);
+
+	}
+
+      alloc_size = GFC_DESCRIPTOR_STRIDE(retarray,rank-1) * extent[rank-1]
+      		 * string_len;
+
+      retarray->offset = 0;
+      retarray->dtype = (array->dtype & ~GFC_DTYPE_RANK_MASK) | rank;
+
+      if (alloc_size == 0)
+	{
+	  /* Make sure we have a zero-sized array.  */
+	  GFC_DIMENSION_SET(retarray->dim[0], 0, -1, 1);
+	  return;
+	}
+      else
+	retarray->base_addr = xmallocarray (alloc_size, sizeof (rtype_name));
+
+    }
+  else
+    {
+      if (rank != GFC_DESCRIPTOR_RANK (retarray))
+	runtime_error ("rank of return array incorrect in u_name intrinsic");
+
+      if (unlikely (compile_options.bounds_check))
+	{
+	  bounds_ifunction_return ((array_t *) retarray, extent,
+				   "return value", "u_name");
+	  bounds_equal_extents ((array_t *) mask, (array_t *) array,
+	  			"MASK argument", "u_name");
+	}
+    }
+
+  for (n = 0; n < rank; n++)
+    {
+      count[n] = 0;
+      dstride[n] = GFC_DESCRIPTOR_STRIDE(retarray,n) * string_len;
+      if (extent[n] <= 0)
+	return;
+    }
+
+  dest = retarray->base_addr;
+  base = array->base_addr;
+
+  while (base)
+    {
+      const atype_name * restrict src;
+      const GFC_LOGICAL_1 * restrict msrc;
+
+      src = base;
+      msrc = mbase;
+      {
+')dnl
+define(START_MASKED_ARRAY_BLOCK,
+`	for (n = 0; n < len; n++, src += delta, msrc += mdelta)
+	  {
+')dnl
+define(FINISH_MASKED_ARRAY_FUNCTION,
+`	  }
+	memcpy (dest, retval, sizeof (*dest) * string_len);
+      }
+      /* Advance to the next element.  */
+      count[0]++;
+      base += sstride[0];
+      mbase += mstride[0];
+      dest += dstride[0];
+      n = 0;
+      while (count[n] == extent[n])
+	{
+	  /* When we get to the end of a dimension, reset it and increment
+	     the next dimension.  */
+	  count[n] = 0;
+	  /* We could precalculate these products, but this is a less
+	     frequently used path so probably not worth it.  */
+	  base -= sstride[n] * extent[n];
+	  mbase -= mstride[n] * extent[n];
+	  dest -= dstride[n] * extent[n];
+	  n++;
+	  if (n >= rank)
+	    {
+	      /* Break out of the loop.  */
+	      base = NULL;
+	      break;
+	    }
+	  else
+	    {
+	      count[n]++;
+	      base += sstride[n];
+	      mbase += mstride[n];
+	      dest += dstride[n];
+	    }
+	}
+    }
+}')dnl
+define(SCALAR_ARRAY_FUNCTION,
+`
+void `s'name`'rtype_qual`_'atype_code (rtype * const restrict,
+        gfc_charlen_type, atype * const restrict,
+	const index_type * const restrict,
+	GFC_LOGICAL_4 *, gfc_charlen_type);
+
+export_proto(`s'name`'rtype_qual`_'atype_code);
+
+void
+`s'name`'rtype_qual`_'atype_code (rtype * const restrict retarray, 
+	gfc_charlen_type xlen, atype * const restrict array, 
+	const index_type * const restrict pdim,
+	GFC_LOGICAL_4 *mask, gfc_charlen_type string_len)
+
+{
+  index_type count[GFC_MAX_DIMENSIONS];
+  index_type extent[GFC_MAX_DIMENSIONS];
+  index_type dstride[GFC_MAX_DIMENSIONS];
+  rtype_name * restrict dest;
+  index_type rank;
+  index_type n;
+  index_type dim;
+
+
+  if (*mask)
+    {
+      name`'rtype_qual`_'atype_code (retarray, xlen, array, pdim, string_len);
+      return;
+    }
+  /* Make dim zero based to avoid confusion.  */
+  dim = (*pdim) - 1;
+  rank = GFC_DESCRIPTOR_RANK (array) - 1;
+
+  if (unlikely (dim < 0 || dim > rank))
+    {
+      runtime_error ("Dim argument incorrect in u_name intrinsic: "
+ 		     "is %ld, should be between 1 and %ld",
+		     (long int) dim + 1, (long int) rank + 1);
+    }
+
+  for (n = 0; n < dim; n++)
+    {
+      extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
+
+      if (extent[n] <= 0)
+	extent[n] = 0;
+    }
+
+  for (n = dim; n < rank; n++)
+    {
+      extent[n] =
+	GFC_DESCRIPTOR_EXTENT(array,n + 1);
+
+      if (extent[n] <= 0)
+	extent[n] = 0;
+    }
+
+  if (retarray->base_addr == NULL)
+    {
+      size_t alloc_size, str;
+
+      for (n = 0; n < rank; n++)
+	{
+	  if (n == 0)
+	    str = 1;
+	  else
+	    str = GFC_DESCRIPTOR_STRIDE(retarray,n-1) * extent[n-1];
+
+	  GFC_DIMENSION_SET(retarray->dim[n], 0, extent[n] - 1, str);
+
+	}
+
+      retarray->offset = 0;
+      retarray->dtype = (array->dtype & ~GFC_DTYPE_RANK_MASK) | rank;
+
+      alloc_size = GFC_DESCRIPTOR_STRIDE(retarray,rank-1) * extent[rank-1]
+      		 * string_len;
+
+      if (alloc_size == 0)
+	{
+	  /* Make sure we have a zero-sized array.  */
+	  GFC_DIMENSION_SET(retarray->dim[0], 0, -1, 1);
+	  return;
+	}
+      else
+	retarray->base_addr = xmallocarray (alloc_size, sizeof (rtype_name));
+    }
+  else
+    {
+      if (rank != GFC_DESCRIPTOR_RANK (retarray))
+	runtime_error ("rank of return array incorrect in"
+		       " u_name intrinsic: is %ld, should be %ld",
+		       (long int) (GFC_DESCRIPTOR_RANK (retarray)),
+		       (long int) rank);
+
+      if (unlikely (compile_options.bounds_check))
+	{
+	  for (n=0; n < rank; n++)
+	    {
+	      index_type ret_extent;
+
+	      ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,n);
+	      if (extent[n] != ret_extent)
+		runtime_error ("Incorrect extent in return value of"
+			       " u_name intrinsic in dimension %ld:"
+			       " is %ld, should be %ld", (long int) n + 1,
+			       (long int) ret_extent, (long int) extent[n]);
+	    }
+	}
+    }
+
+  for (n = 0; n < rank; n++)
+    {
+      count[n] = 0;
+      dstride[n] = GFC_DESCRIPTOR_STRIDE(retarray,n) * string_len;
+    }
+
+  dest = retarray->base_addr;
+
+  while(1)
+    {
+      memset (dest, '$1`, sizeof (*dest) * string_len);
+      count[0]++;
+      dest += dstride[0];
+      n = 0;
+      while (count[n] == extent[n])
+	{
+	  /* When we get to the end of a dimension, reset it and increment
+	     the next dimension.  */
+	  count[n] = 0;
+	  /* We could precalculate these products, but this is a less
+	     frequently used path so probably not worth it.  */
+	  dest -= dstride[n] * extent[n];
+	  n++;
+	  if (n >= rank)
+	    return;
+	  else
+	    {
+	      count[n]++;
+	      dest += dstride[n];
+	    }
+      	}
+    }
+}')dnl
+define(ARRAY_FUNCTION,
+`START_ARRAY_FUNCTION($1)
+$2
+START_ARRAY_BLOCK($1)
+$3
+FINISH_ARRAY_FUNCTION($4)')dnl
+define(MASKED_ARRAY_FUNCTION,
+`START_MASKED_ARRAY_FUNCTION
+$2
+START_MASKED_ARRAY_BLOCK
+$3
+FINISH_MASKED_ARRAY_FUNCTION')dnl
diff --git a/libgfortran/m4/iparm.m4 b/libgfortran/m4/iparm.m4
index 4bf2a3010cf..a5596c98a16 100644
--- a/libgfortran/m4/iparm.m4
+++ b/libgfortran/m4/iparm.m4
@@ -35,3 +35,4 @@ define(name, regexp(regexp(file, `[^/]*$', `\&'), `^\([^_]*\)_', `\1'))dnl
 define(`upcase', `translit(`$*', `a-z', `A-Z')')dnl
 define(`u_name',`regexp(upcase(name),`\([A-Z]*\)',`\1')')dnl
 define(rtype_ccode,ifelse(rtype_letter,`i',rtype_kind,rtype_code))dnl
+define(initval,ifelse(index(name,`maxval'),0,0,index(name,`minval'),0,255))dnl
diff --git a/libgfortran/m4/maxval0s.m4 b/libgfortran/m4/maxval0s.m4
new file mode 100644
index 00000000000..eeb4d7b27e2
--- /dev/null
+++ b/libgfortran/m4/maxval0s.m4
@@ -0,0 +1,58 @@
+`/* Implementation of the MAXLOC intrinsic
+   Copyright 2017 Free Software Foundation, Inc.
+   Contributed by Thomas Koenig
+
+This file is part of the GNU Fortran runtime library (libgfortran).
+
+Libgfortran is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public
+License as published by the Free Software Foundation; either
+version 3 of the License, or (at your option) any later version.
+
+Libgfortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "libgfortran.h"
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <limits.h>'
+
+include(iparm.m4)dnl
+include(iforeach-s2.m4)dnl
+
+`#if defined (HAVE_'atype_name`) && defined (HAVE_'rtype_name`)'
+
+FOREACH_FUNCTION(
+`  const atype_name *retval;
+   retval = ret;'
+,
+`  if (compare_fcn (base, retval, len) > 0)
+    {
+      retval = base;
+    }')
+
+MASKED_FOREACH_FUNCTION(
+`  const atype_name *retval;
+
+  retval = ret;'
+,
+`  if (*mbase && compare_fcn (base, retval, len) > 0)
+    {
+      retval = base;
+    }')
+
+SCALAR_FOREACH_FUNCTION
+
+#endif
diff --git a/libgfortran/m4/maxval1s.m4 b/libgfortran/m4/maxval1s.m4
new file mode 100644
index 00000000000..edf0ef1ba04
--- /dev/null
+++ b/libgfortran/m4/maxval1s.m4
@@ -0,0 +1,61 @@
+`/* Implementation of the MAXVAL intrinsic
+   Copyright 2017 Free Software Foundation, Inc.
+   Contributed by Thomas Koenig
+
+This file is part of the GNU Fortran runtime library (libgfortran).
+
+Libgfortran is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public
+License as published by the Free Software Foundation; either
+version 3 of the License, or (at your option) any later version.
+
+Libgfortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "libgfortran.h"'
+
+include(iparm.m4)dnl
+include(ifunction-s2.m4)dnl
+
+`#if defined (HAVE_'atype_name`) && defined (HAVE_'rtype_name`)'
+
+ARRAY_FUNCTION(0,
+`	const atype_name *retval;
+	retval = base;',
+`		if (compare_fcn (src, retval, string_len) > 0)
+		  {
+		    retval = src;
+		  }', `')
+
+MASKED_ARRAY_FUNCTION(0,
+`	const atype_name *retval;
+	memset (dest, 0, sizeof (*dest) * string_len);
+	retval = dest;',
+`		if (*msrc)
+		      {
+			retval = src;
+			break;
+		      }
+	    }
+	    for (; n < len; n++, src += delta, msrc += mdelta)
+	      {
+		if (*msrc && compare_fcn (src, retval, string_len) > 0)
+		  {
+		    retval = src;
+		  }
+	      ')
+
+SCALAR_ARRAY_FUNCTION(0)
+
+#endif
diff --git a/libgfortran/m4/minval0s.m4 b/libgfortran/m4/minval0s.m4
new file mode 100644
index 00000000000..0bcf543503a
--- /dev/null
+++ b/libgfortran/m4/minval0s.m4
@@ -0,0 +1,58 @@
+`/* Implementation of the MAXLOC intrinsic
+   Copyright 2017 Free Software Foundation, Inc.
+   Contributed by Thomas Koenig
+
+This file is part of the GNU Fortran runtime library (libgfortran).
+
+Libgfortran is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public
+License as published by the Free Software Foundation; either
+version 3 of the License, or (at your option) any later version.
+
+Libgfortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "libgfortran.h"
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <limits.h>'
+
+include(iparm.m4)dnl
+include(iforeach-s2.m4)dnl
+
+`#if defined (HAVE_'atype_name`) && defined (HAVE_'rtype_name`)'
+
+FOREACH_FUNCTION(
+`  const atype_name *retval;
+   retval = ret;'
+,
+`  if (compare_fcn (base, retval, len) < 0)
+    {
+      retval = base;
+    }')
+
+MASKED_FOREACH_FUNCTION(
+`  const atype_name *retval;
+
+  retval = ret;'
+,
+`  if (*mbase && compare_fcn (base, retval, len) < 0)
+    {
+      retval = base;
+    }')
+
+SCALAR_FOREACH_FUNCTION
+
+#endif
diff --git a/libgfortran/m4/minval1s.m4 b/libgfortran/m4/minval1s.m4
new file mode 100644
index 00000000000..3f52bd9bdab
--- /dev/null
+++ b/libgfortran/m4/minval1s.m4
@@ -0,0 +1,61 @@
+`/* Implementation of the MAXVAL intrinsic
+   Copyright 2017 Free Software Foundation, Inc.
+   Contributed by Thomas Koenig
+
+This file is part of the GNU Fortran runtime library (libgfortran).
+
+Libgfortran is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public
+License as published by the Free Software Foundation; either
+version 3 of the License, or (at your option) any later version.
+
+Libgfortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "libgfortran.h"'
+
+include(iparm.m4)dnl
+include(ifunction-s2.m4)dnl
+
+`#if defined (HAVE_'atype_name`) && defined (HAVE_'rtype_name`)'
+
+ARRAY_FUNCTION(255,
+`	const atype_name *retval;
+	retval = base;',
+`		if (compare_fcn (src, retval, string_len) < 0)
+		  {
+		    retval = src;
+		  }', `')
+
+MASKED_ARRAY_FUNCTION(255,
+`	const atype_name *retval;
+	memset (dest, 255, sizeof (*dest) * string_len);
+	retval = dest;',
+`		if (*msrc)
+		      {
+			retval = src;
+			break;
+		      }
+	    }
+	    for (; n < len; n++, src += delta, msrc += mdelta)
+	      {
+		if (*msrc && compare_fcn (src, retval, string_len) < 0)
+		  {
+		    retval = src;
+		  }
+	      ')
+
+SCALAR_ARRAY_FUNCTION(255)
+
+#endif