re PR tree-optimization/79245 (Inefficient loop distribution to memcpy)

2017-01-27  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/79245
	* tree-loop-distribution.c (distribute_loop): Apply cost
	modeling also to detected patterns.

	* gcc.dg/tree-ssa/ldist-23.c: XFAIL.
	* gcc.dg/tree-ssa/ldist-25.c: New testcase.

From-SVN: r244976

gcc/ChangeLog

 2017-01-27  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/79245
+	* tree-loop-distribution.c (distribute_loop): Apply cost
+	modeling also to detected patterns.
+
+2017-01-27  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/71433
 	* tree-vrp.c (register_new_assert_for): Revert earlier changes.
 	(compare_assert_loc): New function.

gcc/testsuite/ChangeLog

+2017-01-27  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/79245
+	* gcc.dg/tree-ssa/ldist-23.c: XFAIL.
+	* gcc.dg/tree-ssa/ldist-25.c: New testcase.
+
 2017-01-27  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/79199

gcc/testsuite/gcc.dg/tree-ssa/ldist-23.c

@@ -29,5 +29,6 @@ int main()
   return 0;
 }
 
-/* { dg-final { scan-tree-dump "split to 1 loops and 1 library call" "ldist" } } */
-/* { dg-final { scan-tree-dump "generated memcpy" "ldist" } } */
+/* XFAILed due to the fix for PR79245.  */
+/* { dg-final { scan-tree-dump "split to 1 loops and 1 library call" "ldist" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump "generated memcpy" "ldist" { xfail *-*-* }  } } */

gcc/testsuite/gcc.dg/tree-ssa/ldist-25.c

+/* { dg-do compile } */
+/* { dg-options "-O3 -ftree-loop-distribute-patterns -fdump-tree-ldist-details" } */
+
+#define k 1335
+double a[k][k];
+double b[k][k];
+double c[k][k];
+
+int x;
+int y;
+
+void
+foo (void)
+{
+  for (int j = 0; j < x; j++)
+    {
+      for (int i = 0; i < y; i++)
+	{
+	  c[j][i] = b[j][i] - a[j][i];
+	  a[j][i] = b[j][i];
+	}
+    }
+}
+
+/* { dg-final { scan-tree-dump "Loop . is the same" "ldist" } } */

gcc/tree-loop-distribution.c

@@ -1548,8 +1548,7 @@ distribute_loop (struct loop *loop, vec<gimple *> stmts,
       for (int j = i + 1;
 	   partitions.iterate (j, &partition); ++j)
 	{
-	  if (!partition_builtin_p (partition)
-	      && similar_memory_accesses (rdg, into, partition))
+	  if (similar_memory_accesses (rdg, into, partition))
 	    {
 	      if (dump_file && (dump_flags & TDF_DETAILS))
 		{