Fix for tree-ssa-pre

	* tree-ssa-sccvn.c (vn_reference_lookup_call): default (NULL) value
	is set to preserve uninitialized value for vnresult.

From-SVN: r214873

gcc/ChangeLog

+2014-09-03  Martin Liska  <mliska@suse.cz>
+
+	* tree-ssa-sccvn.c (vn_reference_lookup_call): default (NULL) value
+	is set to set uninitialized value for vnresult.
+
 2014-09-03  Chung-Ju Wu  <jasonwucj@gmail.com>
 
 	* config/nds32/nds32.c (nds32_must_pass_in_stack): New implementation

gcc/tree-ssa-sccvn.c

@@ -2146,6 +2146,9 @@ void
 vn_reference_lookup_call (gimple call, vn_reference_t *vnresult,
 			  vn_reference_t vr)
 {
+  if (vnresult)
+    *vnresult = NULL;
+
   tree vuse = gimple_vuse (call);
 
   vr->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;