diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -2302,8 +2302,7 @@
 static bool isKnownNonNullFromDominatingCondition(const Value *V,
                                                   const Instruction *CtxI,
                                                   const DominatorTree *DT) {
-  if (isa<Constant>(V))
-    return false;
+  assert(!isa<Constant>(V) && "Called for constant?");
 
   if (!CtxI || !DT)
     return false;