re PR tree-optimization/80631 (Compiling with -O3 -mavx2 gives wrong code)

	PR tree-optimization/80631
	* tree-vect-loop.c (get_initial_def_for_reduction): Fix comment typo.
	(vect_create_epilog_for_reduction): Add INDUC_VAL and INDUC_CODE
	arguments, for INTEGER_INDUC_COND_REDUCTION use INDUC_VAL instead of
	hardcoding zero as the value if COND_EXPR is never true.  For
	INTEGER_INDUC_COND_REDUCTION don't emit the final COND_EXPR if
	INDUC_VAL is equal to INITIAL_DEF, and use INDUC_CODE instead of
	hardcoding MAX_EXPR as the reduction operation.
	(is_nonwrapping_integer_induction): Allow negative step.
	(vectorizable_reduction): Compute INDUC_VAL and INDUC_CODE for
	vect_create_epilog_for_reduction, if no value is suitable, don't
	use INTEGER_INDUC_COND_REDUCTION for now.  Formatting fixes.

	* gcc.dg/vect/pr80631-1.c: New test.
	* gcc.dg/vect/pr80631-2.c: New test.
	* gcc.dg/vect/pr65947-13.c: Expect integer induc cond reduction
	vectorization.

From-SVN: r255574

gcc/ChangeLog

+2017-12-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/80631
+	* tree-vect-loop.c (get_initial_def_for_reduction): Fix comment typo.
+	(vect_create_epilog_for_reduction): Add INDUC_VAL and INDUC_CODE
+	arguments, for INTEGER_INDUC_COND_REDUCTION use INDUC_VAL instead of
+	hardcoding zero as the value if COND_EXPR is never true.  For
+	INTEGER_INDUC_COND_REDUCTION don't emit the final COND_EXPR if
+	INDUC_VAL is equal to INITIAL_DEF, and use INDUC_CODE instead of
+	hardcoding MAX_EXPR as the reduction operation.
+	(is_nonwrapping_integer_induction): Allow negative step.
+	(vectorizable_reduction): Compute INDUC_VAL and INDUC_CODE for
+	vect_create_epilog_for_reduction, if no value is suitable, don't
+	use INTEGER_INDUC_COND_REDUCTION for now.  Formatting fixes.
+
 2017-12-12  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/81889

gcc/testsuite/ChangeLog

+2017-12-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/80631
+	* gcc.dg/vect/pr80631-1.c: New test.
+	* gcc.dg/vect/pr80631-2.c: New test.
+	* gcc.dg/vect/pr65947-13.c: Expect integer induc cond reduction
+	vectorization.
+
 2017-12-12  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/81889

gcc/testsuite/gcc.dg/vect/pr65947-13.c

@@ -6,8 +6,7 @@ extern void abort (void) __attribute__ ((noreturn));
 
 #define N 32
 
-/* Simple condition reduction with a reversed loop.
-   Will fail to vectorize to a simple case.  */
+/* Simple condition reduction with a reversed loop.  */
 
 int
 condition_reduction (int *a, int min_v)
@@ -42,4 +41,4 @@ main (void)
 }
 
 /* { dg-final { scan-tree-dump-times "LOOP VECTORIZED" 2 "vect" } } */
-/* { dg-final { scan-tree-dump-not "condition expression based on integer induction." "vect" } } */
+/* { dg-final { scan-tree-dump-times "condition expression based on integer induction." 4 "vect" } } */

gcc/testsuite/gcc.dg/vect/pr80631-1.c

+/* PR tree-optimization/80631 */
+/* { dg-do run } */
+
+#include "tree-vect.h"
+
+int v[8] = { 77, 1, 79, 3, 4, 3, 6, 7 };
+
+__attribute__((noipa)) void
+f1 (void)
+{
+  int k, r = -1;
+  for (k = 0; k < 8; k++)
+    if (v[k] == 77)
+      r = k;
+  if (r != 0)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f2 (void)
+{
+  int k, r = 4;
+  for (k = 0; k < 8; k++)
+    if (v[k] == 79)
+      r = k;
+  if (r != 2)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f3 (void)
+{
+  int k, r = -17;
+  for (k = 0; k < 8; k++)
+    if (v[k] == 78)
+      r = k;
+  if (r != -17)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f4 (void)
+{
+  int k, r = 7;
+  for (k = 0; k < 8; k++)
+    if (v[k] == 78)
+      r = k;
+  if (r != 7)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f5 (void)
+{
+  int k, r = -1;
+  for (k = 0; k < 8; k++)
+    if (v[k] == 3)
+      r = k;
+  if (r != 5)
+    abort ();
+}
+
+int
+main ()
+{
+  check_vect ();
+  f1 ();
+  f2 ();
+  f3 ();
+  f4 ();
+  f5 ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "LOOP VECTORIZED" 5 "vect" { target vect_condition } } } */
+/* { dg-final { scan-tree-dump-times "condition expression based on integer induction." 10 "vect" { target vect_condition } } } */

gcc/testsuite/gcc.dg/vect/pr80631-2.c

+/* PR tree-optimization/80631 */
+/* { dg-do run } */
+
+#include "tree-vect.h"
+
+int v[8] = { 77, 1, 79, 3, 4, 3, 6, 7 };
+
+__attribute__((noipa)) void
+f1 (void)
+{
+  int k, r = -1;
+  for (k = 7; k >= 0; k--)
+    if (v[k] == 77)
+      r = k;
+  if (r != 0)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f2 (void)
+{
+  int k, r = 4;
+  for (k = 7; k >= 0; k--)
+    if (v[k] == 79)
+      r = k;
+  if (r != 2)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f3 (void)
+{
+  int k, r = -17;
+  for (k = 7; k >= 0; k--)
+    if (v[k] == 78)
+      r = k;
+  if (r != -17)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f4 (void)
+{
+  int k, r = 7;
+  for (k = 7; k >= 0; k--)
+    if (v[k] == 78)
+      r = k;
+  if (r != 7)
+    abort ();
+}
+
+__attribute__((noipa)) void
+f5 (void)
+{
+  int k, r = -1;
+  for (k = 7; k >= 0; k--)
+    if (v[k] == 3)
+      r = k;
+  if (r != 3)
+    abort ();
+}
+
+int
+main ()
+{
+  check_vect ();
+  f1 ();
+  f2 ();
+  f3 ();
+  f4 ();
+  f5 ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "LOOP VECTORIZED" 5 "vect" { target vect_condition } } } */
+/* { dg-final { scan-tree-dump-times "condition expression based on integer induction." 10 "vect" { target vect_condition } } } */