gcc/

	Backport from trunk r243333.
	2016-12-07  Naveen H.S  <Naveen.Hurugalawadi@cavium.com>

	* config/aarch64/aarch64.c
	(aarch64_builtin_support_vector_misalignment): New.
	(TARGET_VECTORIZE_SUPPORT_VECTOR_MISALIGNMENT): Define.

	gcc/testsuite/
	Backport from trunk r243333.
	2016-12-07  Naveen H.S  <Naveen.Hurugalawadi@cavium.com>

	* gcc.target/aarch64/pr71727.c : New Testcase.

Change-Id: Ia6b91005d9fd26b4389c237b58b3f13033070c42

2 files changed, 72 insertions, 0 deletions

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index f222dba7f57..9f9d39fdae8 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -141,6 +141,10 @@ static bool aarch64_vector_mode_supported_p (machine_mode);
 static bool aarch64_vectorize_vec_perm_const_ok (machine_mode vmode,
 						 const unsigned char *sel);
 static int aarch64_address_cost (rtx, machine_mode, addr_space_t, bool);
+static bool aarch64_builtin_support_vector_misalignment (machine_mode mode,
+							 const_tree type,
+							 int misalignment,
+							 bool is_packed);
 
 /* Major revision number of the ARM Architecture implemented by the target.  */
 unsigned aarch64_architecture_version;
@@ -11104,6 +11108,37 @@ aarch64_simd_vector_alignment_reachable (const_tree type, bool is_packed)
   return true;
 }
 
+/* Return true if the vector misalignment factor is supported by the
+   target.  */
+static bool
+aarch64_builtin_support_vector_misalignment (machine_mode mode,
+					     const_tree type, int misalignment,
+					     bool is_packed)
+{
+  if (TARGET_SIMD && STRICT_ALIGNMENT)
+    {
+      /* Return if movmisalign pattern is not supported for this mode.  */
+      if (optab_handler (movmisalign_optab, mode) == CODE_FOR_nothing)
+        return false;
+
+      if (misalignment == -1)
+	{
+	  /* Misalignment factor is unknown at compile time but we know
+	     it's word aligned.  */
+	  if (aarch64_simd_vector_alignment_reachable (type, is_packed))
+            {
+              int element_size = TREE_INT_CST_LOW (TYPE_SIZE (type));
+
+              if (element_size != 64)
+                return true;
+            }
+	  return false;
+	}
+    }
+  return default_builtin_support_vector_misalignment (mode, type, misalignment,
+						      is_packed);
+}
+
 /* If VALS is a vector constant that can be loaded into a register
    using DUP, generate instructions to do so and return an RTX to
    assign to the register.  Otherwise return NULL_RTX.  */
@@ -14381,6 +14416,10 @@ aarch64_optab_supported_p (int op, machine_mode mode1, machine_mode,
 #undef TARGET_VECTOR_MODE_SUPPORTED_P
 #define TARGET_VECTOR_MODE_SUPPORTED_P aarch64_vector_mode_supported_p
 
+#undef TARGET_VECTORIZE_SUPPORT_VECTOR_MISALIGNMENT
+#define TARGET_VECTORIZE_SUPPORT_VECTOR_MISALIGNMENT \
+  aarch64_builtin_support_vector_misalignment
+
 #undef TARGET_ARRAY_MODE_SUPPORTED_P
 #define TARGET_ARRAY_MODE_SUPPORTED_P aarch64_array_mode_supported_p
 
diff --git a/gcc/testsuite/gcc.target/aarch64/pr71727.c b/gcc/testsuite/gcc.target/aarch64/pr71727.c
new file mode 100644
index 00000000000..05eef3e9191
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr71727.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-mstrict-align -O3" } */
+
+struct test_struct_s
+{
+  long a;
+  long b;
+  long c;
+  long d;
+  unsigned long e;
+};
+
+
+char _a;
+struct test_struct_s xarray[128];
+
+void
+_start (void)
+{
+  struct test_struct_s *new_entry;
+
+  new_entry = &xarray[0];
+  new_entry->a = 1;
+  new_entry->b = 2;
+  new_entry->c = 3;
+  new_entry->d = 4;
+  new_entry->e = 5;
+
+  return;
+}
+
+/* { dg-final { scan-assembler-times "mov\tx" 5 {target lp64} } } */
+/* { dg-final { scan-assembler-not "add\tx0, x0, :" {target lp64} } } */