Index: lib/Transforms/Scalar/GVN.cpp
===================================================================
--- lib/Transforms/Scalar/GVN.cpp
+++ lib/Transforms/Scalar/GVN.cpp
@@ -2529,7 +2529,7 @@
     if (isa<Argument>(Op) || isa<Constant>(Op) || isa<GlobalValue>(Op))
       continue;
 
-    if (Value *V = findLeader(Pred, VN.lookup(Op))) {
+    if (Value *V = findLeader(Pred, VN.lookup_or_add(Op))) {
       Instr->setOperand(i, V);
     } else {
       success = false;