* tree-ssa-loop-ivopts.c (expr_invariant_in_loop_p): Bail out at NULL tree refs.

From-SVN: r186693

gcc/ChangeLog

 2012-04-22  Jan Hubicka  <jh@suse.cz>
 
+	* tree-ssa-loop-ivopts.c (expr_invariant_in_loop_p): Bail out at NULL tree refs.
+
+2012-04-22  Jan Hubicka  <jh@suse.cz>
+
 	* lto-symtab.c (lto_varpool_replace_node): Do not merge needed flags.
 	* cgraphbuild.c (record_reference, record_type_list, mark_address,
 	mark_load, mark_store): Do not mark varpool nodes as needed.

gcc/tree-ssa-loop-ivopts.c

@@ -1411,7 +1411,8 @@ expr_invariant_in_loop_p (struct loop *loop, tree expr)
 
   len = TREE_OPERAND_LENGTH (expr);
   for (i = 0; i < len; i++)
-    if (!expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i)))
+    if (TREE_OPERAND (expr, i)
+	&& !expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i)))
       return false;
 
   return true;