re PR lto/47924 (Missed optimization with LTO)

2011-03-01  Richard Guenther  <rguenther@suse.de>

	PR lto/47924
	* lto-streamer.c (lto_record_common_node): Also register
	the canonical type.

	* gcc.dg/lto/pr47924_0.c: New testcase.

From-SVN: r170589

gcc/ChangeLog

 2011-03-01  Richard Guenther  <rguenther@suse.de>
 
+	PR lto/47924
+	* lto-streamer.c (lto_record_common_node): Also register
+	the canonical type.
+
+2011-03-01  Richard Guenther  <rguenther@suse.de>
+
 	PR lto/46911
 	* lto-streamer-in.c (lto_input_ts_decl_common_tree_pointers):
 	Do not stream DECL_ABSTRACT_ORIGIN.

gcc/lto-streamer.c

@@ -527,7 +527,9 @@ lto_record_common_node (tree *nodep, VEC(tree, heap) **common_nodes,
 	 are set by the middle-end.  */
       if (in_lto_p)
 	TYPE_CANONICAL (node) = NULL_TREE;
-      *nodep = node = gimple_register_type (node);
+      node = gimple_register_type (node);
+      TYPE_CANONICAL (node) = gimple_register_canonical_type (node);
+      *nodep = node;
     }
 
   /* Return if node is already seen.  */

gcc/testsuite/ChangeLog

 2011-03-01  Richard Guenther  <rguenther@suse.de>
 
+	PR lto/47924
+	* gcc.dg/lto/pr47924_0.c: New testcase.
+
+2011-03-01  Richard Guenther  <rguenther@suse.de>
+
 	PR lto/46911
 	* gfortran.dg/lto/pr46911_0.f: New testcase.
 

gcc/testsuite/gcc.dg/lto/pr47924_0.c

+/* { dg-lto-do link } */
+/* { dg-lto-options {{-O2 -flto}} } */
+
+extern void link_error (void);
+short *p __attribute__((used));
+int i __attribute__((used));
+
+int main()
+{
+  if (i == 0)
+    return;
+
+  *p = 0;
+
+  if (i == 0)
+    link_error ();
+
+  return 0;
+}