re PR middle-end/45013 (Failed to build 483.xalancbmk in SPEC CPU 2006)

2010-07-21  Richard Guenther  <rguenther@suse.de>

	PR middle-end/45013
	* tree-ssa.c (useless_type_conversion_p): Dispatch to
	gimple_types_compatible_p only when in lto.
	* gimple.c (gimple_types_compatible_p): Use canonical types
	to speed up comparison.

From-SVN: r162371

gcc/ChangeLog

 2010-07-21  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/45013
+	* tree-ssa.c (useless_type_conversion_p): Dispatch to
+	gimple_types_compatible_p only when in lto.
+	* gimple.c (gimple_types_compatible_p): Use canonical types
+	to speed up comparison.
+
+2010-07-21  Richard Guenther  <rguenther@suse.de>
+
 	* tree-flow.h (referenced_var): Move define ...
 	* tree-flow-inline.h (referenced_var): ... here as an inline
 	function.  Assert here ...

gcc/gimple.c

@@ -3360,6 +3360,12 @@ gimple_types_compatible_p (tree t1, tree t2, bool for_merging_p)
   if (t1 == NULL_TREE || t2 == NULL_TREE)
     return 0;
 
+  /* If the types have been previously registered and found equal
+     they still are.  */
+  if (TYPE_CANONICAL (t1)
+      && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
+    return 1;
+
   /* Can't be the same type if the types don't have the same code.  */
   if (TREE_CODE (t1) != TREE_CODE (t2))
     return 0;

gcc/tree-ssa.c

@@ -1426,7 +1426,8 @@ useless_type_conversion_p (tree outer_type, tree inner_type)
      compared types.  */
   else if (AGGREGATE_TYPE_P (inner_type)
 	   && TREE_CODE (inner_type) == TREE_CODE (outer_type))
-    return gimple_types_compatible_p (outer_type, inner_type, false);
+    return (in_lto_p
+	    && gimple_types_compatible_p (outer_type, inner_type, false));
 
   return false;
 }