re PR other/47167 (Performance regression in numerical code)

2011-01-20  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/47167
	* tree-ssa-copyrename.c (copy_rename_partition_coalesce):
	Revert previous change, only avoid enumeral type changes.

From-SVN: r169050

gcc/ChangeLog

+2011-01-20  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/47167
+	* tree-ssa-copyrename.c (copy_rename_partition_coalesce):
+	Revert previous change, only avoid enumeral type changes.
+
 2011-01-19  Dodji Seketeli  <dodji@redhat.com>
 
 	PR c++/47291

gcc/tree-ssa-copyrename.c

@@ -226,11 +226,16 @@ copy_rename_partition_coalesce (var_map map, tree var1, tree var2, FILE *debug)
       ign2 = false;
     }
 
-  /* Don't coalesce if the two variables are not of the same type.  */
-  if (TREE_TYPE (root1) != TREE_TYPE (root2))
+  /* Don't coalesce if the two variables aren't type compatible .  */
+  if (!types_compatible_p (TREE_TYPE (root1), TREE_TYPE (root2))
+      /* There is a disconnect between the middle-end type-system and
+         VRP, avoid coalescing enum types with different bounds.  */
+      || ((TREE_CODE (TREE_TYPE (root1)) == ENUMERAL_TYPE
+	   || TREE_CODE (TREE_TYPE (root2)) == ENUMERAL_TYPE)
+	  && TREE_TYPE (root1) != TREE_TYPE (root2)))
     {
       if (debug)
-	fprintf (debug, " : Different types.  No coalesce.\n");
+	fprintf (debug, " : Incompatible types.  No coalesce.\n");
       return false;
     }