2013-04-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/57000
	* tree-ssa-reassoc.c (pass_reassoc): Add TODO_update_ssa_only_virtuals.

	* gcc.dg/tree-ssa/reassoc-27.c: New testcase.

--- gcc/tree-ssa-reassoc.c	(revision 198086)
+++ gcc/tree-ssa-reassoc.c	(revision 198087)
@@ -4293,6 +4293,7 @@ struct gimple_opt_pass pass_reassoc =
   0,					/* properties_destroyed */
   0,					/* todo_flags_start */
   TODO_verify_ssa
+    | TODO_update_ssa_only_virtuals
     | TODO_verify_flow
     | TODO_ggc_collect			/* todo_flags_finish */
  }
--- gcc/testsuite/gcc.dg/tree-ssa/reassoc-27.c	(revision 0)
+++ gcc/testsuite/gcc.dg/tree-ssa/reassoc-27.c	(revision 198087)
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O -ffast-math -frounding-math -fdump-tree-optimized" } */
+
+double baz (double foo, double bar)
+{
+  return foo * foo * foo * foo * bar * bar * bar * bar;
+}
+
+/* We should re-associate this as (foo * bar)**3.  */
+/* { dg-final { scan-tree-dump-times " \\\* " 3 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */