Index: lib/IR/ConstantFold.cpp
===================================================================
--- lib/IR/ConstantFold.cpp
+++ lib/IR/ConstantFold.cpp
@@ -349,19 +349,29 @@
       if (NumElems == 0)
         return ConstantExpr::getNullValue(DestTy);
       // Check for a struct with all members having the same size.
-      Constant *MemberSize =
+      Constant *FirstMemberSize =
         getFoldedSizeOf(STy->getElementType(0), DestTy, true);
+      Constant *StructSize = FirstMemberSize;
+
       bool AllSame = true;
-      for (unsigned i = 1; i != NumElems; ++i)
-        if (MemberSize !=
-            getFoldedSizeOf(STy->getElementType(i), DestTy, true)) {
+      for (unsigned i = 1; i != NumElems; ++i){
+        Constant *MemberSize = getFoldedSizeOf(STy->getElementType(i), DestTy, true);
+        StructSize = ConstantExpr::getNUWAdd(StructSize, MemberSize);
+
+        if (FirstMemberSize != MemberSize){
+          if (!Folded)
+            return nullptr;
+
           AllSame = false;
-          break;
         }
+      }
+
       if (AllSame) {
         Constant *N = ConstantInt::get(DestTy, NumElems);
-        return ConstantExpr::getNUWMul(MemberSize, N);
+        return ConstantExpr::getNUWMul(FirstMemberSize, N);
       }
+
+      return ConstantExpr::getCast(CastInst::getCastOpcode(StructSize, false, DestTy, false), StructSize, DestTy);
     }
 
   // Pointer size doesn't depend on the pointee type, so canonicalize them