diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index c03f66a7ad6..ba1f775c055 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2012-09-25  Zhenqiang Chen <zhenqiang.chen@linaro.org>
+
+	PR c++/50970
+	* typeck.c (cp_build_binary_op): Check side effects before generating
+	pfn and delta related expressions.
+
 2012-09-24  Lawrence Crowl  <crowl@google.com>
 
 	* init.c (build_new_1): Change to new double_int API.
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index ad4b0903d67..884f7d0573b 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -4159,18 +4159,23 @@ cp_build_binary_op (location_t location,
 	  if (TARGET_PTRMEMFUNC_VBIT_LOCATION
 	      == ptrmemfunc_vbit_in_delta)
 	    {
-	      tree pfn0 = pfn_from_ptrmemfunc (op0);
-	      tree delta0 = delta_from_ptrmemfunc (op0);
-	      tree e1 = cp_build_binary_op (location,
-					    EQ_EXPR,
-	  			            pfn0,	
-				      	    build_zero_cst (TREE_TYPE (pfn0)),
-					    complain);
-	      tree e2 = cp_build_binary_op (location,
-					    BIT_AND_EXPR, 
-					    delta0,
-				            integer_one_node,
-					    complain);
+	      tree pfn0, delta0, e1, e2;
+
+	      if (TREE_SIDE_EFFECTS (op0))
+		op0 = save_expr (op0);
+
+	      pfn0 = pfn_from_ptrmemfunc (op0);
+	      delta0 = delta_from_ptrmemfunc (op0);
+	      e1 = cp_build_binary_op (location,
+				       EQ_EXPR,
+	  			       pfn0,
+				       build_zero_cst (TREE_TYPE (pfn0)),
+				       complain);
+	      e2 = cp_build_binary_op (location,
+				       BIT_AND_EXPR,
+				       delta0,
+				       integer_one_node,
+				       complain);
 	      
 	      if ((complain & tf_warning)
 		  && c_inhibit_evaluation_warnings == 0