diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -5599,8 +5599,8 @@
 
   Value *Result = CGF.EmitNeonCall(F, Ops, s);
   llvm::Type *ResultType = CGF.ConvertType(E->getType());
-  if (ResultType->getPrimitiveSizeInBits() <
-      Result->getType()->getPrimitiveSizeInBits())
+  if (TypeSize::isKnownLT(ResultType->getPrimitiveSizeInBits(),
+                          Result->getType()->getPrimitiveSizeInBits()))
     return CGF.Builder.CreateExtractElement(Result, C0);
 
   return CGF.Builder.CreateBitCast(Result, ResultType, s);