gimple.c (gimple_register_canonical_type): Use the main-variant leader for…

gimple.c (gimple_register_canonical_type): Use the main-variant leader for computing the canonical type.

2011-05-17  Richard Guenther  <rguenther@suse.de>

	* gimple.c (gimple_register_canonical_type): Use the main-variant
	leader for computing the canonical type.

From-SVN: r173826

gcc/ChangeLog

+2011-05-17  Richard Guenther  <rguenther@suse.de>
+
+	* gimple.c (gimple_register_canonical_type): Use the main-variant
+	leader for computing the canonical type.
+
 2011-05-17  Nick Clifton  <nickc@redhat.com>
 
 	* config/rx/rx.c (rx_memory_move_cost): Include cost of register

gcc/gimple.c

@@ -4856,19 +4856,14 @@ gimple_register_canonical_type (tree t)
   if (TYPE_CANONICAL (t))
     return TYPE_CANONICAL (t);
 
-  /* Always register the type itself first so that if it turns out
-     to be the canonical type it will be the one we merge to as well.  */
-  t = gimple_register_type (t);
+  /* Use the leader of our main variant for determining our canonical
+     type.  The main variant leader is a type that will always
+     prevail.  */
+  t = gimple_register_type (TYPE_MAIN_VARIANT (t));
 
   if (TYPE_CANONICAL (t))
     return TYPE_CANONICAL (t);
 
-  /* Always register the main variant first.  This is important so we
-     pick up the non-typedef variants as canonical, otherwise we'll end
-     up taking typedef ids for structure tags during comparison.  */
-  if (TYPE_MAIN_VARIANT (t) != t)
-    gimple_register_canonical_type (TYPE_MAIN_VARIANT (t));
-
   if (gimple_canonical_types == NULL)
     gimple_canonical_types = htab_create_ggc (16381, gimple_canonical_type_hash,
 					      gimple_canonical_type_eq, 0);