Index: llvm/lib/CodeGen/AtomicExpandPass.cpp
===================================================================
--- llvm/lib/CodeGen/AtomicExpandPass.cpp
+++ llvm/lib/CodeGen/AtomicExpandPass.cpp
@@ -1447,8 +1447,10 @@
   default:
     llvm_unreachable("Unhandled case in tryExpandAtomicCmpXchg");
   case TargetLoweringBase::AtomicExpansionKind::None:
-    if (ValueSize < MinCASSize)
+    if (ValueSize < MinCASSize) {
       expandPartwordCmpXchg(CI);
+      return true;
+    }
     return false;
   case TargetLoweringBase::AtomicExpansionKind::LLSC: {
     return expandAtomicCmpXchg(CI);