diff --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -758,6 +758,15 @@
   // Because multiple allocas may own the same field slot,
   // we add allocas to field here.
   B.addFieldForAllocas(F, FrameData, Shape);
+  // Add PromiseAlloca to Allocas list so that
+  // 1. updateLayoutIndex could update its index after
+  // `performOptimizedStructLayout`
+  // 2. it is processed in insertSpills.
+  if (Shape.ABI == coro::ABI::Switch && PromiseAlloca)
+    // We assume that the promise alloca won't be modified before
+    // CoroBegin and no alias will be create before CoroBegin.
+    FrameData.Allocas.emplace_back(
+        PromiseAlloca, DenseMap<Instruction *, llvm::Optional<APInt>>{}, false);
   // Create an entry for every spilled value.
   for (auto &S : FrameData.Spills) {
     FieldIDType Id = B.addField(S.first->getType(), None);
@@ -2271,13 +2280,6 @@
       Shape.ABI == coro::ABI::Async)
     sinkSpillUsesAfterCoroBegin(F, FrameData, Shape.CoroBegin);
   Shape.FrameTy = buildFrameType(F, Shape, FrameData);
-  // Add PromiseAlloca to Allocas list so that it is processed in insertSpills.
-  if (Shape.ABI == coro::ABI::Switch && Shape.SwitchLowering.PromiseAlloca)
-    // We assume that the promise alloca won't be modified before
-    // CoroBegin and no alias will be create before CoroBegin.
-    FrameData.Allocas.emplace_back(
-        Shape.SwitchLowering.PromiseAlloca,
-        DenseMap<Instruction *, llvm::Optional<APInt>>{}, false);
   Shape.FramePtr = insertSpills(FrameData, Shape);
   lowerLocalAllocas(LocalAllocas, DeadInstructions);