[clang] [llvm] Revert "[CoroSplit] Erase trivially dead allocas after spilling" (PR #189311)

[Weibo He via llvm-commits]

https://github.com/NewSigma created https://github.com/llvm/llvm-project/pull/189311

I think I forgot to update the FrameData after erasing. I'll check it locally.

Reverts llvm/llvm-project#189295

>From 448f2c60dcff8df6a39b06fd95e92f6cc86e185e Mon Sep 17 00:00:00 2001
From: Weibo He <NewSigma at 163.com>
Date: Mon, 30 Mar 2026 12:11:31 +0800
Subject: [PATCH] Revert "[CoroSplit] Erase trivially dead allocas after
 spilling (#189295)"

This reverts commit 14e7dbd99a70258a0deb283785996f2e11be7e2b.
---
 clang/test/CodeGenCoroutines/coro-suspend-cleanups.cpp         | 2 ++
 llvm/lib/Transforms/Coroutines/CoroFrame.cpp                   | 3 ---
 .../Transforms/Coroutines/coro-await-suspend-lower-invoke.ll   | 1 +
 llvm/test/Transforms/Coroutines/coro-await-suspend-lower.ll    | 1 +
 llvm/test/Transforms/Coroutines/coro-split-sink-lifetime-01.ll | 1 +
 5 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/clang/test/CodeGenCoroutines/coro-suspend-cleanups.cpp b/clang/test/CodeGenCoroutines/coro-suspend-cleanups.cpp
index 5872a75b26de5..77abc53ce2e71 100644
--- a/clang/test/CodeGenCoroutines/coro-suspend-cleanups.cpp
+++ b/clang/test/CodeGenCoroutines/coro-suspend-cleanups.cpp
@@ -39,6 +39,8 @@ coroutine ArrayInitCoro() {
   //  - We activate the cleanup after the first element and deactivate it in await.ready (see cleanup.isactive).
 
   // CHECK-LABEL: define dso_local void @_Z13ArrayInitCorov
+  // CHECK: %arrayinit.endOfInit = alloca ptr, align 8
+  // CHECK: %cleanup.isactive = alloca i1, align 1
   Printy arr[2] = {
     Printy("a"),
     // CHECK:       store i1 true, ptr %cleanup.isactive.reload.addr, align 1
diff --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
index 96dad79374160..83b40ee927b51 100644
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -1212,9 +1212,6 @@ static void insertSpills(const FrameDataInfo &FrameData, coro::Shape &Shape) {
 
     for (Instruction *I : UsersToUpdate)
       I->replaceUsesOfWith(Alloca, G);
-
-    if (Alloca->user_empty())
-      Alloca->eraseFromParent();
   }
   Builder.SetInsertPoint(&*Shape.getInsertPtAfterFramePtr());
   for (const auto &A : FrameData.Allocas) {
diff --git a/llvm/test/Transforms/Coroutines/coro-await-suspend-lower-invoke.ll b/llvm/test/Transforms/Coroutines/coro-await-suspend-lower-invoke.ll
index 87309042f18bf..78540d9363cc6 100644
--- a/llvm/test/Transforms/Coroutines/coro-await-suspend-lower-invoke.ll
+++ b/llvm/test/Transforms/Coroutines/coro-await-suspend-lower-invoke.ll
@@ -105,6 +105,7 @@ declare noalias ptr @malloc(i32)
 declare void @free(ptr)
 ; CHECK-LABEL: define void @f() personality i32 0 {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[AWAITER:%.*]] = alloca [[AWAITER:%.*]], align 8
 ; CHECK-NEXT:    [[ID:%.*]] = call token @llvm.coro.id(i32 0, ptr null, ptr @f, ptr @f.resumers)
 ; CHECK-NEXT:    [[ALLOC:%.*]] = call ptr @malloc(i32 24)
 ; CHECK-NEXT:    [[HDL:%.*]] = call noalias nonnull ptr @llvm.coro.begin(token [[ID]], ptr [[ALLOC]])
diff --git a/llvm/test/Transforms/Coroutines/coro-await-suspend-lower.ll b/llvm/test/Transforms/Coroutines/coro-await-suspend-lower.ll
index bb3fa099de763..d6c93cad08a90 100644
--- a/llvm/test/Transforms/Coroutines/coro-await-suspend-lower.ll
+++ b/llvm/test/Transforms/Coroutines/coro-await-suspend-lower.ll
@@ -82,6 +82,7 @@ declare noalias ptr @malloc(i32)
 declare void @free(ptr)
 ; CHECK-LABEL: define void @f() {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[AWAITER:%.*]] = alloca [[AWAITER:%.*]], align 8
 ; CHECK-NEXT:    [[ID:%.*]] = call token @llvm.coro.id(i32 0, ptr null, ptr @f, ptr @f.resumers)
 ; CHECK-NEXT:    [[ALLOC:%.*]] = call ptr @malloc(i32 24)
 ; CHECK-NEXT:    [[HDL:%.*]] = call noalias nonnull ptr @llvm.coro.begin(token [[ID]], ptr [[ALLOC]])
diff --git a/llvm/test/Transforms/Coroutines/coro-split-sink-lifetime-01.ll b/llvm/test/Transforms/Coroutines/coro-split-sink-lifetime-01.ll
index 4cacbcf402adf..2ebd52328de52 100644
--- a/llvm/test/Transforms/Coroutines/coro-split-sink-lifetime-01.ll
+++ b/llvm/test/Transforms/Coroutines/coro-split-sink-lifetime-01.ll
@@ -105,6 +105,7 @@ declare void @llvm.lifetime.end.p0(ptr nocapture) #4
 ; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
 ; CHECK-NEXT:    [[REF_TMP7:%.*]] = alloca %"struct.lean_future<int>::Awaiter", align 8
+; CHECK-NEXT:    [[TESTVAL:%.*]] = alloca i32, align 4
 ; CHECK-NEXT:    [[ID:%.*]] = call token @llvm.coro.id(i32 0, ptr null, ptr null, ptr @a_optnone.resumers)
 ; CHECK-NEXT:    [[ALLOC:%.*]] = call ptr @malloc(i64 16)
 ; CHECK-NEXT:    [[VFRAME:%.*]] = call noalias nonnull ptr @llvm.coro.begin(token [[ID]], ptr [[ALLOC]])