diff --git a/llvm/lib/Transforms/Coroutines/CoroSplit.cpp b/llvm/lib/Transforms/Coroutines/CoroSplit.cpp
--- a/llvm/lib/Transforms/Coroutines/CoroSplit.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroSplit.cpp
@@ -913,6 +913,21 @@
                          Shape.FrameSize, Shape.FrameAlign);
     break;
   case coro::ABI::Async: {
+    auto *ActiveAsyncSuspend = cast<CoroSuspendAsyncInst>(ActiveSuspend);
+    if (OrigF.hasParamAttribute(Shape.AsyncLowering.ContextArgNo,
+                                Attribute::SwiftAsync)) {
+      uint32_t ArgAttributeIndices =
+          ActiveAsyncSuspend->getStorageArgumentIndex();
+      auto ContextArgIndex = ArgAttributeIndices & 0xff;
+      addAsyncContextAttrs(NewAttrs, Context, ContextArgIndex);
+
+      // `swiftasync` must preceed `swiftself` so 0 is not a valid index for
+      // `swiftself`.
+      auto SwiftSelfIndex = ArgAttributeIndices >> 8;
+      if (SwiftSelfIndex)
+        addSwiftSelfAttrs(NewAttrs, Context, SwiftSelfIndex);
+    }
+
     // Transfer the original function's attributes.
     auto FnAttrs = OrigF.getAttributes().getFnAttributes();
     NewAttrs =
@@ -952,24 +967,9 @@
   // followed by a return.
   // Don't change returns to unreachable because that will trip up the verifier.
   // These returns should be unreachable from the clone.
-  case coro::ABI::Async: {
-    auto *ActiveAsyncSuspend = cast<CoroSuspendAsyncInst>(ActiveSuspend);
-    if (OrigF.hasParamAttribute(Shape.AsyncLowering.ContextArgNo,
-                                Attribute::SwiftAsync)) {
-      uint32_t ArgAttributeIndices =
-          ActiveAsyncSuspend->getStorageArgumentIndex();
-      auto ContextArgIndex = ArgAttributeIndices & 0xff;
-      addAsyncContextAttrs(NewAttrs, Context, ContextArgIndex);
-
-      // `swiftasync` must preceed `swiftself` so 0 is not a valid index for
-      // `swiftself`.
-      auto SwiftSelfIndex = ArgAttributeIndices >> 8;
-      if (SwiftSelfIndex)
-        addSwiftSelfAttrs(NewAttrs, Context, SwiftSelfIndex);
-    }
+  case coro::ABI::Async:
     break;
   }
-  }
 
   NewF->setAttributes(NewAttrs);
   NewF->setCallingConv(Shape.getResumeFunctionCC());