[Bug tree-optimization/46398] early FRE miscompiles simple testcase

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46398

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-11-09 
16:49:48 UTC ---
-O1 on any platform with the following patch applied (or not-yet-found
carefully
crafted disabling of passes before the existing FRE pass):

Index: gcc/passes.c
===================================================================
--- gcc/passes.c        (revision 166472)
+++ gcc/passes.c        (working copy)
@@ -776,6 +776,7 @@ init_optimization_passes (void)
             locals into SSA form if possible.  */
          NEXT_PASS (pass_build_ealias);
          NEXT_PASS (pass_sra_early);
+      NEXT_PASS (pass_fre);
          NEXT_PASS (pass_copy_prop);
          NEXT_PASS (pass_merge_phi);
          NEXT_PASS (pass_cd_dce);