re PR tree-optimization/70138 (wrong code at -O3 on x86_64-linux-gnu)

2016-03-09  Richard Biener  <rguenther@suse.de>
	Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/70138
	* tree-vect-loop-manip.c (vect_update_ivs_after_vectorizer):
	Also skip vect_double_reduction_def.

	* gcc.dg/vect/pr70138-1.c: New testcase.
	* gcc.dg/vect/pr70138-2.c: Likewise.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r234086

gcc/ChangeLog

+2016-03-09  Richard Biener  <rguenther@suse.de>
+	Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/70138
+	* tree-vect-loop-manip.c (vect_update_ivs_after_vectorizer):
+	Also skip vect_double_reduction_def.
+
 2016-03-09  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/70049

gcc/testsuite/ChangeLog

+2016-03-09  Richard Biener  <rguenther@suse.de>
+	Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/70138
+	* gcc.dg/vect/pr70138-1.c: New testcase.
+	* gcc.dg/vect/pr70138-2.c: Likewise.
+
 2016-03-09  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/70049

gcc/testsuite/gcc.dg/vect/pr70138-1.c

+/* { dg-do run } */
+
+#include "tree-vect.h"
+
+double u[33 * 33];
+
+__attribute__((noinline, noclone)) static void
+foo (int *x)
+{
+  double c = 0.0;
+  int a, b;
+  for (a = 0; a < 33; a++)
+    {
+      for (b = 0; b < 33; b++)
+	c = c + u[34 * a];
+      u[34 * a] *= 2.0;
+    }
+  *x = c;
+}
+
+int
+main ()
+{
+  int d, e;
+  check_vect ();
+  for (d = 0; d < 33 * 33; d++)
+    {
+      u[d] = 499.0;
+      __asm__ volatile ("" : : : "memory");
+    }
+  for (d = 0; d < 33; d++)
+    {
+      u[d * 34] = (d + 2);
+      __asm__ volatile ("" : : : "memory");
+    }
+  foo (&e);
+  if (e != 33 * (2 + 34) / 2 * 33)
+    __builtin_abort ();
+  return 0;
+}

gcc/testsuite/gcc.dg/vect/pr70138-2.c

+/* { dg-do run } */
+
+#include "tree-vect.h"
+
+double u[33];
+
+__attribute__((noinline, noclone)) static void
+foo (int *x)
+{
+  double c = 0.0;
+  int a, b;
+  for (a = 0; a < 33; a++)
+    {
+      for (b = 0; b < 33; b++)
+	c = c + u[a];
+      u[a] *= 2.0;
+    }
+  *x = c;
+}
+
+int
+main ()
+{
+  int d, e;
+  check_vect ();
+  for (d = 0; d < 33; d++)
+    {
+      u[d] = (d + 2);
+      __asm__ volatile ("" : : : "memory");
+    }
+  foo (&e);
+  if (e != 33 * (2 + 34) / 2 * 33)
+    __builtin_abort ();
+  return 0;
+}

gcc/tree-vect-loop-manip.c

@@ -1692,7 +1692,8 @@ vect_update_ivs_after_vectorizer (loop_vec_info loop_vinfo, tree niters,
 
       /* Skip reduction phis.  */
       stmt_info = vinfo_for_stmt (phi);
-      if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def)
+      if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def
+	  || STMT_VINFO_DEF_TYPE (stmt_info) == vect_double_reduction_def)
         {
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,