Index: lib/Transforms/Scalar/NewGVN.cpp
===================================================================
--- lib/Transforms/Scalar/NewGVN.cpp
+++ lib/Transforms/Scalar/NewGVN.cpp
@@ -1079,10 +1079,10 @@
   assert(
       !isa<Instruction>(NewClass->RepLeader) || !NewClass->RepLeader ||
       I == NewClass->RepLeader ||
-      !DT->properlyDominates(
+      (!DT->properlyDominates(
           I->getParent(),
           cast<Instruction>(NewClass->RepLeader)->getParent()) &&
-          "New class for instruction should not be dominated by instruction");
+          "New class for instruction should not be dominated by instruction"));
 
   if (NewClass->RepLeader != I) {
     auto DFSNum = InstrDFS.lookup(I);