tree-loop-distribution.c (can_generate_builtin): Reject volatile stmts.

2012-05-21  Richard Guenther  <rguenther@suse.de>

	* tree-loop-distribution.c (can_generate_builtin): Reject
	volatile stmts.

	* gcc.dg/torture/ldist-1.c: New testcase.

From-SVN: r187707

gcc/ChangeLog

+2012-05-21  Richard Guenther  <rguenther@suse.de>
+
+	* tree-loop-distribution.c (can_generate_builtin): Reject
+	volatile stmts.
+
 2012-05-21  Chung-Lin Tang  <cltang@codesourcery.com>
 
 	* Makefile.in (options.c): Add options.h to included header

gcc/testsuite/ChangeLog

+2012-05-21  Richard Guenther  <rguenther@suse.de>
+
+	* gcc.dg/torture/ldist-1.c: New testcase.
+
 2012-05-20  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/lto13.adb: New test.

gcc/testsuite/gcc.dg/torture/ldist-1.c

+/* { dg-do compile } */
+/* { dg-options "-ftree-loop-distribute-patterns" } */
+
+void foo (volatile int *p, int n)
+{
+  int i;
+  for (i = 0; i < n; ++i)
+    p[i] = 0;
+}
+
+/* { dg-final { scan-assembler-not "memset" } } */
+/* { dg-final { cleanup-tree-dump "ldist" } } */

gcc/tree-loop-distribution.c

@@ -822,8 +822,10 @@ can_generate_builtin (struct graph *rdg, bitmap partition)
       nb_reads++;
     else if (RDG_MEM_WRITE_STMT (rdg, i))
       {
+	gimple stmt = RDG_STMT (rdg, i);
 	nb_writes++;
-	if (stmt_with_adjacent_zero_store_dr_p (RDG_STMT (rdg, i)))
+	if (!gimple_has_volatile_ops (stmt)
+	    && stmt_with_adjacent_zero_store_dr_p (stmt))
 	  stores_zero++;
       }