diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp
--- a/llvm/lib/IR/ConstantFold.cpp
+++ b/llvm/lib/IR/ConstantFold.cpp
@@ -355,8 +355,9 @@
 static Constant *getFoldedSizeOf(Type *Ty, Type *DestTy, bool Folded,
                                  DenseMap<Type *, Constant *> &Cache) {
   // Check for previously generated folded size constant.
-  if (Cache.find(Ty) != Cache.end())
-    return Cache[Ty];
+  auto CacheIter = Cache.find(Ty);
+  if (CacheIter != Cache.end())
+    return CacheIter->second;
 
   if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
     Constant *N = ConstantInt::get(DestTy, ATy->getNumElements());