re PR tree-optimization/32921 (Revision 126326 causes 12% slowdown)

2008-04-30  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/32921
	* tree-ssa-loop-im.c (mem_refs_may_alias_p): Disambiguate with TBAA.

From-SVN: r134838

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2822569..ffd78f4 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2008-04-30  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/32921
+       * tree-ssa-loop-im.c (mem_refs_may_alias_p): Disambiguate with TBAA.
+
 2008-04-30  Richard Sandiford  <rsandifo@nildram.co.uk>
 
        * config/arm/arm.c (arm_unwind_emit): Use

diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c
index 6402a8e..c896abb 100644 (file)
--- a/gcc/tree-ssa-loop-im.c
+++ b/gcc/tree-ssa-loop-im.c
@@ -1640,6 +1640,8 @@ mem_refs_may_alias_p (tree mem1, tree mem2, struct pointer_map_t **ttae_cache)
          && SSA_VAR_P (mem1)
          && !AGGREGATE_TYPE_P (TREE_TYPE (mem1)))
        return false;
+      if (!alias_sets_conflict_p (get_alias_set (mem1), get_alias_set (mem2)))
+       return false;
     }
 
   /* The expansion of addresses may be a bit expensive, thus we only do