[clang] [llvm] [coroutine] Implement llvm.coro.await.suspend intrinsic (PR #79712)

[Chuanqi Xu via cfe-commits]

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@@ -167,6 +167,53 @@ class CoroCloner {
 
 } // end anonymous namespace
 
+// FIXME:
+// Lower the intrinisc in CoroEarly phase if coroutine frame doesn't escape
+// and it is known that other transformations, for example, sanitizers
+// won't lead to incorrect code.
+static void lowerAwaitSuspend(IRBuilder<> &Builder, CoroAwaitSuspendInst *CB) {
+  auto Wrapper = CB->getWrapperFunction();
+  auto Awaiter = CB->getAwaiter();
+  auto FramePtr = CB->getFrame();
+
+  Builder.SetInsertPoint(CB);
+
+  CallBase *NewCall = nullptr;
+  if (auto Invoke = dyn_cast<InvokeInst>(CB)) {
+    auto WrapperInvoke =
+        Builder.CreateInvoke(Wrapper, Invoke->getNormalDest(),
+                             Invoke->getUnwindDest(), {Awaiter, FramePtr});
+
+    WrapperInvoke->setCallingConv(Invoke->getCallingConv());
+    std::copy(Invoke->bundle_op_info_begin(), Invoke->bundle_op_info_end(),
+              WrapperInvoke->bundle_op_info_begin());
+    AttributeList NewAttributes =
+        Invoke->getAttributes().removeParamAttributes(Invoke->getContext(), 2);
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ChuanqiXu9 wrote:

What is the attribute to be removed? Let's add a comment here to make it clear.

https://github.com/llvm/llvm-project/pull/79712