[Pipelines] Remove Legacy Passes in Coroutines

[ChuanqiXu]

Summary

I found there are some patches which removed legacy passes. So I am wondering if we could remove the legacy passes in coroutines now. So that we could simplify the codes further.

[nikic]

llvm/tools/opt/opt.cpp

374

You can also drop the option now. It is only meaningful with legacy PM, as coroutines are always enabled with new PM.

[ChuanqiXu]

Address comments and fix tests.

[ChuanqiXu]

llvm/test/Transforms/Coroutines/coro-async-addr-lifetime-start-bug.ll

1–2 ↗

(On Diff #423346)

I am wondering if the 2 tests are redundant?

[nikic]

llvm/test/Transforms/Coroutines/coro-async-addr-lifetime-start-bug.ll

1–2 ↗

(On Diff #423346)

Yes, these are redundant, you can drop one of them.

[ChuanqiXu]

Address comments.

[MaskRay]

I found there are some patches which removed legacy passes.

Yes. I have sent some after I saw nikic did for some.

An important user of us swiftshader uses createCoroCleanupLegacyPass. Would you mind giving us few days so that they can migrate away?

[ChuanqiXu]

In D123918#3457108, @MaskRay wrote:

I found there are some patches which removed legacy passes.

Yes. I have sent some after I saw nikic did for some.

An important user of us swiftshader uses createCoroCleanupLegacyPass. Would you mind giving us few days so that they can migrate away?

Of course!

[aeubanks]

In D123918#3457923, @ChuanqiXu wrote:

In D123918#3457108, @MaskRay wrote:

I found there are some patches which removed legacy passes.

Yes. I have sent some after I saw nikic did for some.

An important user of us swiftshader uses createCoroCleanupLegacyPass. Would you mind giving us few days so that they can migrate away?

Of course!

We've fixed up the user, feel free to commit this patch.

llvm/bindings/go/llvm/transforms_pmbuilder.go

 
 func (pmb PassManagerBuilder) SetDisableSimplifyLibCalls(val bool) {
   C.LLVMPassManagerBuilderSetDisableSimplifyLibCalls(pmb.C, boolToLLVMBool(val))
 }
 
 func (pmb PassManagerBuilder) UseInlinerWithThreshold(threshold uint) {
   C.LLVMPassManagerBuilderUseInlinerWithThreshold(pmb.C, C.uint(threshold))
 }
-
-func (pmb PassManagerBuilder) AddCoroutinePassesToExtensionPoints() {
-  C.LLVMPassManagerBuilderAddCoroutinePassesToExtensionPoints(pmb.C);
-}

llvm/include/llvm-c/Transforms/Coroutines.h

-/*===-- Coroutines.h - Coroutines Library C Interface -----------*- C++ -*-===*\
-|*                                                                            *|
-|* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
-|* Exceptions.                                                                *|
-|* See https://llvm.org/LICENSE.txt for license information.                  *|
-|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
-|*                                                                            *|
-|*===----------------------------------------------------------------------===*|
-|*                                                                            *|
-|* This header declares the C interface to libLLVMCoroutines.a, which         *|
-|* implements various scalar transformations of the LLVM IR.                  *|
-|*                                                                            *|
-|* Many exotic languages can interoperate with C code but have a harder time  *|
-|* with C++ due to name mangling. So in addition to C, this interface enables *|
-|* tools written in such languages.                                           *|
-|*                                                                            *|
-\*===----------------------------------------------------------------------===*/
-
-#ifndef LLVM_C_TRANSFORMS_COROUTINES_H
-#define LLVM_C_TRANSFORMS_COROUTINES_H
-
-#include "llvm-c/ExternC.h"
-#include "llvm-c/Types.h"
-#include "llvm-c/Transforms/PassManagerBuilder.h"
-
-LLVM_C_EXTERN_C_BEGIN
-
-/**
- * @defgroup LLVMCTransformsCoroutines Coroutine transformations
- * @ingroup LLVMCTransforms
- *
- * @{
- */
-
-/** See llvm::createCoroEarlyLegacyPass function. */
-void LLVMAddCoroEarlyPass(LLVMPassManagerRef PM);
-
-/** See llvm::createCoroSplitLegacyPass function. */
-void LLVMAddCoroSplitPass(LLVMPassManagerRef PM);
-
-/** See llvm::createCoroElideLegacyPass function. */
-void LLVMAddCoroElidePass(LLVMPassManagerRef PM);
-
-/** See llvm::createCoroCleanupLegacyPass function. */
-void LLVMAddCoroCleanupPass(LLVMPassManagerRef PM);
-
-/** See llvm::addCoroutinePassesToExtensionPoints. */
-void LLVMPassManagerBuilderAddCoroutinePassesToExtensionPoints(LLVMPassManagerBuilderRef PMB);
-
-/**
- * @}
- */
-
-LLVM_C_EXTERN_C_END
-
-#endif

llvm/include/llvm/InitializePasses.h

 void initializeIPO(PassRegistry&);
 
 /// Initialize all passes linked into the Instrumentation library.
 void initializeInstrumentation(PassRegistry&);
 
 /// Initialize all passes linked into the Analysis library.
 void initializeAnalysis(PassRegistry&);
 
-/// Initialize all passes linked into the Coroutines library.
-void initializeCoroutines(PassRegistry&);
-
 /// Initialize all passes linked into the CodeGen library.
 void initializeCodeGen(PassRegistry&);
 
 /// Initialize all passes linked into the GlobalISel library.
 void initializeGlobalISel(PassRegistry&);
 
 /// Initialize all passes linked into the CodeGen library.
 void initializeTarget(PassRegistry&);

llvm/include/llvm/Transforms/Coroutines.h

-//===-- Coroutines.h - Coroutine Transformations ----------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-// Declare accessor functions for coroutine lowering passes.
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_TRANSFORMS_COROUTINES_H
-#define LLVM_TRANSFORMS_COROUTINES_H
-
-namespace llvm {
-
-class Pass;
-class PassManagerBuilder;
-
-/// Add all coroutine passes to appropriate extension points.
-void addCoroutinePassesToExtensionPoints(PassManagerBuilder &Builder);
-
-/// Lower coroutine intrinsics that are not needed by later passes.
-Pass *createCoroEarlyLegacyPass();
-
-/// Split up coroutines into multiple functions driving their state machines.
-Pass *createCoroSplitLegacyPass(bool IsOptimizing = false);
-
-/// Analyze coroutines use sites, devirtualize resume/destroy calls and elide
-/// heap allocation for coroutine frame where possible.
-Pass *createCoroElideLegacyPass();
-
-/// Lower all remaining coroutine intrinsics.
-Pass *createCoroCleanupLegacyPass();
-
-}
-
-#endif

llvm/lib/Transforms/Coroutines/CoroCleanup.cpp

PreservedAnalyses CoroCleanupPass::run(Function &F,
                                        FunctionAnalysisManager &AM) {
   auto &M = *F.getParent();
   if (!declaresCoroCleanupIntrinsics(M) ||
       !Lowerer(M).lowerRemainingCoroIntrinsics(F))
     return PreservedAnalyses::all();
 
   return PreservedAnalyses::none();
 }
-
-namespace {
-
-struct CoroCleanupLegacy : FunctionPass {
-  static char ID; // Pass identification, replacement for typeid
-
-  CoroCleanupLegacy() : FunctionPass(ID) {
-    initializeCoroCleanupLegacyPass(*PassRegistry::getPassRegistry());
-  }
-
-  std::unique_ptr<Lowerer> L;
-
-  // This pass has work to do only if we find intrinsics we are going to lower
-  // in the module.
-  bool doInitialization(Module &M) override {
-    if (declaresCoroCleanupIntrinsics(M))
-      L = std::make_unique<Lowerer>(M);
-    return false;
-  }
-
-  bool runOnFunction(Function &F) override {
-    if (L)
-      return L->lowerRemainingCoroIntrinsics(F);
-    return false;
-  }
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    if (!L)
-      AU.setPreservesAll();
-  }
-  StringRef getPassName() const override { return "Coroutine Cleanup"; }
-};
-}
-
-char CoroCleanupLegacy::ID = 0;
-INITIALIZE_PASS(CoroCleanupLegacy, "coro-cleanup",
-                "Lower all coroutine related intrinsics", false, false)
-
-Pass *llvm::createCoroCleanupLegacyPass() { return new CoroCleanupLegacy(); }

llvm/lib/Transforms/Coroutines/CoroEarly.cpp

PreservedAnalyses CoroEarlyPass::run(Function &F, FunctionAnalysisManager &) {
   Module &M = *F.getParent();
   if (!declaresCoroEarlyIntrinsics(M) || !Lowerer(M).lowerEarlyIntrinsics(F))
     return PreservedAnalyses::all();
 
   PreservedAnalyses PA;
   PA.preserveSet<CFGAnalyses>();
   return PA;
 }
-
-namespace {
-
-struct CoroEarlyLegacy : public FunctionPass {
-  static char ID; // Pass identification, replacement for typeid.
-  CoroEarlyLegacy() : FunctionPass(ID) {
-    initializeCoroEarlyLegacyPass(*PassRegistry::getPassRegistry());
-  }
-
-  std::unique_ptr<Lowerer> L;
-
-  // This pass has work to do only if we find intrinsics we are going to lower
-  // in the module.
-  bool doInitialization(Module &M) override {
-    if (declaresCoroEarlyIntrinsics(M))
-      L = std::make_unique<Lowerer>(M);
-    return false;
-  }
-
-  bool runOnFunction(Function &F) override {
-    if (!L)
-      return false;
-
-    return L->lowerEarlyIntrinsics(F);
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesCFG();
-  }
-  StringRef getPassName() const override {
-    return "Lower early coroutine intrinsics";
-  }
-};
-}
-
-char CoroEarlyLegacy::ID = 0;
-INITIALIZE_PASS(CoroEarlyLegacy, "coro-early",
-                "Lower early coroutine intrinsics", false, false)
-
-Pass *llvm::createCoroEarlyLegacyPass() { return new CoroEarlyLegacy(); }

llvm/lib/Transforms/Coroutines/CoroElide.cpp

#ifndef NDEBUG
             << CoroId->getFunction()->getName() << "\n";
 #endif
     }
   }
 
   return true;
 }
 
-// See if there are any coro.subfn.addr instructions referring to coro.devirt
-// trigger, if so, replace them with a direct call to devirt trigger function.
-static bool replaceDevirtTrigger(Function &F) {
-  SmallVector<CoroSubFnInst *, 1> DevirtAddr;
-  for (auto &I : instructions(F))
-    if (auto *SubFn = dyn_cast<CoroSubFnInst>(&I))
-      if (SubFn->getIndex() == CoroSubFnInst::RestartTrigger)
-        DevirtAddr.push_back(SubFn);
-
-  if (DevirtAddr.empty())
-    return false;
-
-  Module &M = *F.getParent();
-  Function *DevirtFn = M.getFunction(CORO_DEVIRT_TRIGGER_FN);
-  assert(DevirtFn && "coro.devirt.fn not found");
-  replaceWithConstant(DevirtFn, DevirtAddr);
-
-  return true;
-}
-
 static bool declaresCoroElideIntrinsics(Module &M) {
   return coro::declaresIntrinsics(M, {"llvm.coro.id", "llvm.coro.id.async"});
 }
 
 PreservedAnalyses CoroElidePass::run(Function &F, FunctionAnalysisManager &AM) {
   auto &M = *F.getParent();
   if (!declaresCoroElideIntrinsics(M))
     return PreservedAnalyses::all();
PreservedAnalyses CoroElidePass::run(Function &F, FunctionAnalysisManager &AM) {
   DominatorTree &DT = AM.getResult<DominatorTreeAnalysis>(F);
 
   bool Changed = false;
   for (auto *CII : L.CoroIds)
     Changed |= L.processCoroId(CII, AA, DT);
 
   return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
 }
-
-namespace {
-struct CoroElideLegacy : FunctionPass {
-  static char ID;
-  CoroElideLegacy() : FunctionPass(ID) {
-    initializeCoroElideLegacyPass(*PassRegistry::getPassRegistry());
-  }
-
-  std::unique_ptr<Lowerer> L;
-
-  bool doInitialization(Module &M) override {
-    if (declaresCoroElideIntrinsics(M))
-      L = std::make_unique<Lowerer>(M);
-    return false;
-  }
-
-  bool runOnFunction(Function &F) override {
-    if (!L)
-      return false;
-
-    bool Changed = false;
-
-    if (F.hasFnAttribute(CORO_PRESPLIT_ATTR))
-      Changed = replaceDevirtTrigger(F);
-
-    L->CoroIds.clear();
-    L->collectPostSplitCoroIds(&F);
-    // If we did not find any coro.id, there is nothing to do.
-    if (L->CoroIds.empty())
-      return Changed;
-
-    AAResults &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
-    DominatorTree &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-
-    for (auto *CII : L->CoroIds)
-      Changed |= L->processCoroId(CII, AA, DT);
-
-    return Changed;
-  }
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<AAResultsWrapperPass>();
-    AU.addRequired<DominatorTreeWrapperPass>();
-  }
-  StringRef getPassName() const override { return "Coroutine Elision"; }
-};
-}
-
-char CoroElideLegacy::ID = 0;
-INITIALIZE_PASS_BEGIN(
-    CoroElideLegacy, "coro-elide",
-    "Coroutine frame allocation elision and indirect calls replacement", false,
-    false)
-INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
-INITIALIZE_PASS_END(
-    CoroElideLegacy, "coro-elide",
-    "Coroutine frame allocation elision and indirect calls replacement", false,
-    false)
-
-Pass *llvm::createCoroElideLegacyPass() { return new CoroElideLegacy(); }

llvm/lib/Transforms/Coroutines/CoroInternal.h

 #include "llvm/Transforms/Coroutines.h"
 
 namespace llvm {
 
 class CallGraph;
 class CallGraphSCC;
 class PassRegistry;
 
-void initializeCoroEarlyLegacyPass(PassRegistry &);
-void initializeCoroSplitLegacyPass(PassRegistry &);
-void initializeCoroElideLegacyPass(PassRegistry &);
-void initializeCoroCleanupLegacyPass(PassRegistry &);
-
 // CoroEarly pass marks every function that has coro.begin with a string
 // attribute "coroutine.presplit"="0". CoroSplit pass processes the coroutine
 // twice. First, it lets it go through complete IPO optimization pipeline as a
 // single function. It forces restart of the pipeline by inserting an indirect
 // call to an empty function "coro.devirt.trigger" which is devirtualized by
 // CoroElide pass that triggers a restart of the pipeline by CGPassManager.
 // When CoroSplit pass sees the same coroutine the second time, it splits it up,
 // adds coroutine subfunctions to the SCC to be processed by IPO pipeline.

 #define CORO_DEVIRT_TRIGGER_FN "coro.devirt.trigger"
 
 namespace coro {
 
 bool declaresAnyIntrinsic(const Module &M);
 bool declaresIntrinsics(const Module &M,
                         const std::initializer_list<StringRef>);
 void replaceCoroFree(CoroIdInst *CoroId, bool Elide);
-void updateCallGraph(Function &Caller, ArrayRef<Function *> Funcs,
-                     CallGraph &CG, CallGraphSCC &SCC);
+
 /// Recover a dbg.declare prepared by the frontend and emit an alloca
 /// holding a pointer to the coroutine frame.
 void salvageDebugInfo(
     SmallDenseMap<llvm::Value *, llvm::AllocaInst *, 4> &DbgPtrAllocaCache,
     DbgVariableIntrinsic *DVI, bool OptimizeFrame);
 
 // Keeps data and helper functions for lowering coroutine intrinsics.
 struct LowererBase {

llvm/lib/Transforms/Coroutines/CoroSplit.cpp

 // resume or cleanup pass for every suspend point.
 static Function *createClone(Function &F, const Twine &Suffix,
                              coro::Shape &Shape, CoroCloner::Kind FKind) {
   CoroCloner Cloner(F, Suffix, Shape, FKind);
   Cloner.create();
   return Cloner.getFunction();
 }
 
-/// Remove calls to llvm.coro.end in the original function.
-static void removeCoroEnds(const coro::Shape &Shape, CallGraph *CG) {
-  for (auto End : Shape.CoroEnds) {
-    replaceCoroEnd(End, Shape, Shape.FramePtr, /*in resume*/ false, CG);
-  }
-}
-
 static void updateAsyncFuncPointerContextSize(coro::Shape &Shape) {
   assert(Shape.ABI == coro::ABI::Async);
 
   auto *FuncPtrStruct = cast<ConstantStruct>(
       Shape.AsyncLowering.AsyncFuncPointer->getInitializer());
   auto *OrigRelativeFunOffset = FuncPtrStruct->getOperand(0);
   auto *OrigContextSize = FuncPtrStruct->getOperand(1);
   auto *NewContextSize = ConstantInt::get(OrigContextSize->getType(),
for (auto &BB : F) {
     }
   }
   for (auto *DDI : Worklist)
     coro::salvageDebugInfo(DbgPtrAllocaCache, DDI, Shape.OptimizeFrame);
 
   return Shape;
 }
 
-static void
-updateCallGraphAfterCoroutineSplit(Function &F, const coro::Shape &Shape,
-                                   const SmallVectorImpl<Function *> &Clones,
-                                   CallGraph &CG, CallGraphSCC &SCC) {
-  if (!Shape.CoroBegin)
-    return;
-
-  removeCoroEnds(Shape, &CG);
-  postSplitCleanup(F);
-
-  // Update call graph and add the functions we created to the SCC.
-  coro::updateCallGraph(F, Clones, CG, SCC);
-}
-
 static void updateCallGraphAfterCoroutineSplit(
     LazyCallGraph::Node &N, const coro::Shape &Shape,
     const SmallVectorImpl<Function *> &Clones, LazyCallGraph::SCC &C,
     LazyCallGraph &CG, CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR,
     FunctionAnalysisManager &FAM) {
   if (!Shape.CoroBegin)
     return;
 
static void updateCallGraphAfterCoroutineSplit(
   }
 
   // Do some cleanup and let the CGSCC infra see if we've cleaned up any edges
   // to the split functions.
   postSplitCleanup(N.getFunction());
   updateCGAndAnalysisManagerForFunctionPass(CG, C, N, AM, UR, FAM);
 }
 
-// When we see the coroutine the first time, we insert an indirect call to a
-// devirt trigger function and mark the coroutine that it is now ready for
-// split.
-// Async lowering uses this after it has split the function to restart the
-// pipeline.
-static void prepareForSplit(Function &F, CallGraph &CG,
-                            bool MarkForAsyncRestart = false) {
-  Module &M = *F.getParent();
-  LLVMContext &Context = F.getContext();
-#ifndef NDEBUG
-  Function *DevirtFn = M.getFunction(CORO_DEVIRT_TRIGGER_FN);
-  assert(DevirtFn && "coro.devirt.trigger function not found");
-#endif
-
-  F.addFnAttr(CORO_PRESPLIT_ATTR, MarkForAsyncRestart
-                                      ? ASYNC_RESTART_AFTER_SPLIT
-                                      : PREPARED_FOR_SPLIT);
-
-  // Insert an indirect call sequence that will be devirtualized by CoroElide
-  // pass:
-  //    %0 = call i8* @llvm.coro.subfn.addr(i8* null, i8 -1)
-  //    %1 = bitcast i8* %0 to void(i8*)*
-  //    call void %1(i8* null)
-  coro::LowererBase Lowerer(M);
-  Instruction *InsertPt =
-      MarkForAsyncRestart ? F.getEntryBlock().getFirstNonPHIOrDbgOrLifetime()
-                          : F.getEntryBlock().getTerminator();
-  auto *Null = ConstantPointerNull::get(Type::getInt8PtrTy(Context));
-  auto *DevirtFnAddr =
-      Lowerer.makeSubFnCall(Null, CoroSubFnInst::RestartTrigger, InsertPt);
-  FunctionType *FnTy = FunctionType::get(Type::getVoidTy(Context),
-                                         {Type::getInt8PtrTy(Context)}, false);
-  auto *IndirectCall = CallInst::Create(FnTy, DevirtFnAddr, Null, "", InsertPt);
-
-  // Update CG graph with an indirect call we just added.
-  CG[&F]->addCalledFunction(IndirectCall, CG.getCallsExternalNode());
-}
-
-// Make sure that there is a devirtualization trigger function that the
-// coro-split pass uses to force a restart of the CGSCC pipeline. If the devirt
-// trigger function is not found, we will create one and add it to the current
-// SCC.
-static void createDevirtTriggerFunc(CallGraph &CG, CallGraphSCC &SCC) {
-  Module &M = CG.getModule();
-  if (M.getFunction(CORO_DEVIRT_TRIGGER_FN))
-    return;
-
-  LLVMContext &C = M.getContext();
-  auto *FnTy = FunctionType::get(Type::getVoidTy(C), Type::getInt8PtrTy(C),
-                                 /*isVarArg=*/false);
-  Function *DevirtFn =
-      Function::Create(FnTy, GlobalValue::LinkageTypes::PrivateLinkage,
-                       CORO_DEVIRT_TRIGGER_FN, &M);
-  DevirtFn->addFnAttr(Attribute::AlwaysInline);
-  auto *Entry = BasicBlock::Create(C, "entry", DevirtFn);
-  ReturnInst::Create(C, Entry);
-
-  auto *Node = CG.getOrInsertFunction(DevirtFn);
-
-  SmallVector<CallGraphNode *, 8> Nodes(SCC.begin(), SCC.end());
-  Nodes.push_back(Node);
-  SCC.initialize(Nodes);
-}
-
 /// Replace a call to llvm.coro.prepare.retcon.
 static void replacePrepare(CallInst *Prepare, LazyCallGraph &CG,
                            LazyCallGraph::SCC &C) {
   auto CastFn = Prepare->getArgOperand(0); // as an i8*
   auto Fn = CastFn->stripPointerCasts();   // as its original type
 
   // Attempt to peephole this pattern:
   //    %0 = bitcast [[TYPE]] @some_function to i8*
static void replacePrepare(CallInst *Prepare, LazyCallGraph &CG,
   // Kill dead bitcasts.
   while (auto *Cast = dyn_cast<BitCastInst>(CastFn)) {
     if (!Cast->use_empty())
       break;
     CastFn = Cast->getOperand(0);
     Cast->eraseFromParent();
   }
 }
-/// Replace a call to llvm.coro.prepare.retcon.
-static void replacePrepare(CallInst *Prepare, CallGraph &CG) {
-  auto CastFn = Prepare->getArgOperand(0); // as an i8*
-  auto Fn = CastFn->stripPointerCasts(); // as its original type
-
-  // Find call graph nodes for the preparation.
-  CallGraphNode *PrepareUserNode = nullptr, *FnNode = nullptr;
-  if (auto ConcreteFn = dyn_cast<Function>(Fn)) {
-    PrepareUserNode = CG[Prepare->getFunction()];
-    FnNode = CG[ConcreteFn];
-  }
-
-  // Attempt to peephole this pattern:
-  //    %0 = bitcast [[TYPE]] @some_function to i8*
-  //    %1 = call @llvm.coro.prepare.retcon(i8* %0)
-  //    %2 = bitcast %1 to [[TYPE]]
-  // ==>
-  //    %2 = @some_function
-  for (Use &U : llvm::make_early_inc_range(Prepare->uses())) {
-    // Look for bitcasts back to the original function type.
-    auto *Cast = dyn_cast<BitCastInst>(U.getUser());
-    if (!Cast || Cast->getType() != Fn->getType()) continue;
-
-    // Check whether the replacement will introduce new direct calls.
-    // If so, we'll need to update the call graph.
-    if (PrepareUserNode) {
-      for (auto &Use : Cast->uses()) {
-        if (auto *CB = dyn_cast<CallBase>(Use.getUser())) {
-          if (!CB->isCallee(&Use))
-            continue;
-          PrepareUserNode->removeCallEdgeFor(*CB);
-          PrepareUserNode->addCalledFunction(CB, FnNode);
-        }
-      }
-    }
-
-    // Replace and remove the cast.
-    Cast->replaceAllUsesWith(Fn);
-    Cast->eraseFromParent();
-  }
-
-  // Replace any remaining uses with the function as an i8*.
-  // This can never directly be a callee, so we don't need to update CG.
-  Prepare->replaceAllUsesWith(CastFn);
-  Prepare->eraseFromParent();
-
-  // Kill dead bitcasts.
-  while (auto *Cast = dyn_cast<BitCastInst>(CastFn)) {
-    if (!Cast->use_empty()) break;
-    CastFn = Cast->getOperand(0);
-    Cast->eraseFromParent();
-  }
-}
 
 static bool replaceAllPrepares(Function *PrepareFn, LazyCallGraph &CG,
                                LazyCallGraph::SCC &C) {
   bool Changed = false;
   for (Use &P : llvm::make_early_inc_range(PrepareFn->uses())) {
     // Intrinsics can only be used in calls.
     auto *Prepare = cast<CallInst>(P.getUser());
     replacePrepare(Prepare, CG, C);
     Changed = true;
   }
 
   return Changed;
 }
 
-/// Remove calls to llvm.coro.prepare.retcon, a barrier meant to prevent
-/// IPO from operating on calls to a retcon coroutine before it's been
-/// split.  This is only safe to do after we've split all retcon
-/// coroutines in the module.  We can do that this in this pass because
-/// this pass does promise to split all retcon coroutines (as opposed to
-/// switch coroutines, which are lowered in multiple stages).
-static bool replaceAllPrepares(Function *PrepareFn, CallGraph &CG) {
-  bool Changed = false;
-  for (Use &P : llvm::make_early_inc_range(PrepareFn->uses())) {
-    // Intrinsics can only be used in calls.
-    auto *Prepare = cast<CallInst>(P.getUser());
-    replacePrepare(Prepare, CG);
-    Changed = true;
-  }
-
-  return Changed;
-}
-
-static bool declaresCoroSplitIntrinsics(const Module &M) {
-  return coro::declaresIntrinsics(M, {"llvm.coro.begin",
-                                      "llvm.coro.prepare.retcon",
-                                      "llvm.coro.prepare.async"});
-}
-
 static void addPrepareFunction(const Module &M,
                                SmallVectorImpl<Function *> &Fns,
                                StringRef Name) {
   auto *PrepareFn = M.getFunction(Name);
   if (PrepareFn && !PrepareFn->use_empty())
     Fns.push_back(PrepareFn);
 }
 
PreservedAnalyses CoroSplitPass::run(LazyCallGraph::SCC &C,
   if (!PrepareFns.empty()) {
     for (auto *PrepareFn : PrepareFns) {
       replaceAllPrepares(PrepareFn, CG, C);
     }
   }
 
   return PreservedAnalyses::none();
 }
-
-namespace {
-
-// We present a coroutine to LLVM as an ordinary function with suspension
-// points marked up with intrinsics. We let the optimizer party on the coroutine
-// as a single function for as long as possible. Shortly before the coroutine is
-// eligible to be inlined into its callers, we split up the coroutine into parts
-// corresponding to initial, resume and destroy invocations of the coroutine,
-// add them to the current SCC and restart the IPO pipeline to optimize the
-// coroutine subfunctions we extracted before proceeding to the caller of the
-// coroutine.
-struct CoroSplitLegacy : public CallGraphSCCPass {
-  static char ID; // Pass identification, replacement for typeid
-
-  CoroSplitLegacy(bool OptimizeFrame = false)
-      : CallGraphSCCPass(ID), OptimizeFrame(OptimizeFrame) {
-    initializeCoroSplitLegacyPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool Run = false;
-  bool OptimizeFrame;
-
-  // A coroutine is identified by the presence of coro.begin intrinsic, if
-  // we don't have any, this pass has nothing to do.
-  bool doInitialization(CallGraph &CG) override {
-    Run = declaresCoroSplitIntrinsics(CG.getModule());
-    return CallGraphSCCPass::doInitialization(CG);
-  }
-
-  bool runOnSCC(CallGraphSCC &SCC) override {
-    if (!Run)
-      return false;
-
-    // Check for uses of llvm.coro.prepare.retcon.
-    SmallVector<Function *, 2> PrepareFns;
-    auto &M = SCC.getCallGraph().getModule();
-    addPrepareFunction(M, PrepareFns, "llvm.coro.prepare.retcon");
-    addPrepareFunction(M, PrepareFns, "llvm.coro.prepare.async");
-
-    // Find coroutines for processing.
-    SmallVector<Function *, 4> Coroutines;
-    for (CallGraphNode *CGN : SCC)
-      if (auto *F = CGN->getFunction())
-        if (F->hasFnAttribute(CORO_PRESPLIT_ATTR))
-          Coroutines.push_back(F);
-
-    if (Coroutines.empty() && PrepareFns.empty())
-      return false;
-
-    CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
-
-    if (Coroutines.empty()) {
-      bool Changed = false;
-      for (auto *PrepareFn : PrepareFns)
-        Changed |= replaceAllPrepares(PrepareFn, CG);
-      return Changed;
-    }
-
-    createDevirtTriggerFunc(CG, SCC);
-
-    // Split all the coroutines.
-    for (Function *F : Coroutines) {
-      Attribute Attr = F->getFnAttribute(CORO_PRESPLIT_ATTR);
-      StringRef Value = Attr.getValueAsString();
-      LLVM_DEBUG(dbgs() << "CoroSplit: Processing coroutine '" << F->getName()
-                        << "' state: " << Value << "\n");
-      // Async lowering marks coroutines to trigger a restart of the pipeline
-      // after it has split them.
-      if (Value == ASYNC_RESTART_AFTER_SPLIT) {
-        F->removeFnAttr(CORO_PRESPLIT_ATTR);
-        continue;
-      }
-      if (Value == UNPREPARED_FOR_SPLIT) {
-        prepareForSplit(*F, CG);
-        continue;
-      }
-      F->removeFnAttr(CORO_PRESPLIT_ATTR);
-
-      SmallVector<Function *, 4> Clones;
-      const coro::Shape Shape = splitCoroutine(*F, Clones, OptimizeFrame);
-      updateCallGraphAfterCoroutineSplit(*F, Shape, Clones, CG, SCC);
-      if (Shape.ABI == coro::ABI::Async) {
-        // Restart SCC passes.
-        // Mark function for CoroElide pass. It will devirtualize causing a
-        // restart of the SCC pipeline.
-        prepareForSplit(*F, CG, true /*MarkForAsyncRestart*/);
-      }
-    }
-
-    for (auto *PrepareFn : PrepareFns)
-      replaceAllPrepares(PrepareFn, CG);
-
-    return true;
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    CallGraphSCCPass::getAnalysisUsage(AU);
-  }
-
-  StringRef getPassName() const override { return "Coroutine Splitting"; }
-};
-
-} // end anonymous namespace
-
-char CoroSplitLegacy::ID = 0;
-
-INITIALIZE_PASS_BEGIN(
-    CoroSplitLegacy, "coro-split",
-    "Split coroutine into a set of functions driving its state machine", false,
-    false)
-INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
-INITIALIZE_PASS_END(
-    CoroSplitLegacy, "coro-split",
-    "Split coroutine into a set of functions driving its state machine", false,
-    false)
-
-Pass *llvm::createCoroSplitLegacyPass(bool OptimizeFrame) {
-  return new CoroSplitLegacy(OptimizeFrame);
-}

llvm/lib/Transforms/Coroutines/Coroutines.cpp

 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include <cassert>
 #include <cstddef>
 #include <utility>
 
 using namespace llvm;
 
-void llvm::initializeCoroutines(PassRegistry &Registry) {
-  initializeCoroEarlyLegacyPass(Registry);
-  initializeCoroSplitLegacyPass(Registry);
-  initializeCoroElideLegacyPass(Registry);
-  initializeCoroCleanupLegacyPass(Registry);
-}
-
-static void addCoroutineOpt0Passes(const PassManagerBuilder &Builder,
-                                   legacy::PassManagerBase &PM) {
-  PM.add(createCoroSplitLegacyPass());
-  PM.add(createCoroElideLegacyPass());
-
-  PM.add(createBarrierNoopPass());
-  PM.add(createCoroCleanupLegacyPass());
-}
-
-static void addCoroutineEarlyPasses(const PassManagerBuilder &Builder,
-                                    legacy::PassManagerBase &PM) {
-  PM.add(createCoroEarlyLegacyPass());
-}
-
-static void addCoroutineScalarOptimizerPasses(const PassManagerBuilder &Builder,
-                                              legacy::PassManagerBase &PM) {
-  PM.add(createCoroElideLegacyPass());
-}
-
-static void addCoroutineSCCPasses(const PassManagerBuilder &Builder,
-                                  legacy::PassManagerBase &PM) {
-  PM.add(createCoroSplitLegacyPass(Builder.OptLevel != 0));
-}
-
-static void addCoroutineOptimizerLastPasses(const PassManagerBuilder &Builder,
-                                            legacy::PassManagerBase &PM) {
-  PM.add(createCoroCleanupLegacyPass());
-}
-
-void llvm::addCoroutinePassesToExtensionPoints(PassManagerBuilder &Builder) {
-  Builder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
-                       addCoroutineEarlyPasses);
-  Builder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
-                       addCoroutineOpt0Passes);
-  Builder.addExtension(PassManagerBuilder::EP_CGSCCOptimizerLate,
-                       addCoroutineSCCPasses);
-  Builder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
-                       addCoroutineScalarOptimizerPasses);
-  Builder.addExtension(PassManagerBuilder::EP_OptimizerLast,
-                       addCoroutineOptimizerLastPasses);
-}
-
 // Construct the lowerer base class and initialize its members.
 coro::LowererBase::LowererBase(Module &M)
     : TheModule(M), Context(M.getContext()),
       Int8Ptr(Type::getInt8PtrTy(Context)),
       ResumeFnType(FunctionType::get(Type::getVoidTy(Context), Int8Ptr,
                                      /*isVarArg=*/false)),
       NullPtr(ConstantPointerNull::get(Int8Ptr)) {}
 
Value *Replacement =
             : CoroFrees.front()->getFrame();
 
   for (CoroFreeInst *CF : CoroFrees) {
     CF->replaceAllUsesWith(Replacement);
     CF->eraseFromParent();
   }
 }
 
-// FIXME: This code is stolen from CallGraph::addToCallGraph(Function *F), which
-// happens to be private. It is better for this functionality exposed by the
-// CallGraph.
-static void buildCGN(CallGraph &CG, CallGraphNode *Node) {
-  Function *F = Node->getFunction();
-
-  // Look for calls by this function.
-  for (Instruction &I : instructions(F))
-    if (auto *Call = dyn_cast<CallBase>(&I)) {
-      const Function *Callee = Call->getCalledFunction();
-      if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
-        // Indirect calls of intrinsics are not allowed so no need to check.
-        // We can be more precise here by using TargetArg returned by
-        // Intrinsic::isLeaf.
-        Node->addCalledFunction(Call, CG.getCallsExternalNode());
-      else if (!Callee->isIntrinsic())
-        Node->addCalledFunction(Call, CG.getOrInsertFunction(Callee));
-    }
-}
-
-// Rebuild CGN after we extracted parts of the code from ParentFunc into
-// NewFuncs. Builds CGNs for the NewFuncs and adds them to the current SCC.
-void coro::updateCallGraph(Function &ParentFunc, ArrayRef<Function *> NewFuncs,
-                           CallGraph &CG, CallGraphSCC &SCC) {
-  // Rebuild CGN from scratch for the ParentFunc
-  auto *ParentNode = CG[&ParentFunc];
-  ParentNode->removeAllCalledFunctions();
-  buildCGN(CG, ParentNode);
-
-  SmallVector<CallGraphNode *, 8> Nodes(SCC.begin(), SCC.end());
-
-  for (Function *F : NewFuncs) {
-    CallGraphNode *Callee = CG.getOrInsertFunction(F);
-    Nodes.push_back(Callee);
-    buildCGN(CG, Callee);
-  }
-
-  SCC.initialize(Nodes);
-}
-
 static void clear(coro::Shape &Shape) {
   Shape.CoroBegin = nullptr;
   Shape.CoroEnds.clear();
   Shape.CoroSizes.clear();
   Shape.CoroSuspends.clear();
 
   Shape.FrameTy = nullptr;
   Shape.FramePtr = nullptr;
if (!MustTailCallFunc)
     return;
   auto *FnTy = MustTailCallFunc->getFunctionType();
   if (FnTy->getNumParams() != (arg_size() - 3))
     fail(this,
          "llvm.coro.end.async must tail call function argument type must "
          "match the tail arguments",
          MustTailCallFunc);
 }
-
-void LLVMAddCoroEarlyPass(LLVMPassManagerRef PM) {
-  unwrap(PM)->add(createCoroEarlyLegacyPass());
-}
-
-void LLVMAddCoroSplitPass(LLVMPassManagerRef PM) {
-  unwrap(PM)->add(createCoroSplitLegacyPass());
-}
-
-void LLVMAddCoroElidePass(LLVMPassManagerRef PM) {
-  unwrap(PM)->add(createCoroElideLegacyPass());
-}
-
-void LLVMAddCoroCleanupPass(LLVMPassManagerRef PM) {
-  unwrap(PM)->add(createCoroCleanupLegacyPass());
-}
-
-void
-LLVMPassManagerBuilderAddCoroutinePassesToExtensionPoints(LLVMPassManagerBuilderRef PMB) {
-  PassManagerBuilder *Builder = unwrap(PMB);
-  addCoroutinePassesToExtensionPoints(*Builder);
-}

llvm/test/Transforms/Coroutines/coro-cleanup-lowering.ll

 ; Make sure that all library helper coro intrinsics are lowered.
-; RUN: opt < %s -coro-cleanup -S | FileCheck %s
 ; RUN: opt < %s -passes=coro-cleanup -S | FileCheck %s
 
 ; CHECK-LABEL: @uses_library_support_coro_intrinsics(
 ; CHECK-NOT:     @llvm.coro
 ; CHECK:         ret void
 
 define void @uses_library_support_coro_intrinsics(i8* %hdl) {
 entry:

llvm/tools/llvm-opt-fuzzer/llvm-opt-fuzzer.cpp

extern "C" LLVM_ATTRIBUTE_USED int LLVMFuzzerInitialize(
   // Initialize llvm
   //
 
   InitializeAllTargets();
   InitializeAllTargetMCs();
 
   PassRegistry &Registry = *PassRegistry::getPassRegistry();
   initializeCore(Registry);
-  initializeCoroutines(Registry);
   initializeScalarOpts(Registry);
   initializeObjCARCOpts(Registry);
   initializeVectorization(Registry);
   initializeIPO(Registry);
   initializeAnalysis(Registry);
   initializeTransformUtils(Registry);
   initializeInstCombine(Registry);
   initializeAggressiveInstCombine(Registry);

llvm/tools/opt/opt.cpp

static void AddOptimizationPasses(legacy::PassManagerBase &MPM,
 
   Builder.LoopVectorize = OptLevel > 1 && SizeLevel < 2;
 
   Builder.SLPVectorize = OptLevel > 1 && SizeLevel < 2;
 
   if (TM)
     TM->adjustPassManager(Builder);
 
-  if (Coroutines)
-    addCoroutinePassesToExtensionPoints(Builder);
-
   switch (PGOKindFlag) {
   case InstrGen:
     Builder.EnablePGOInstrGen = true;
     Builder.PGOInstrGen = ProfileFile;
     break;
   case InstrUse:
     Builder.PGOInstrUse = ProfileFile;
     break;
int main(int argc, char **argv) {
   InitializeAllTargets();
   InitializeAllTargetMCs();
   InitializeAllAsmPrinters();
   InitializeAllAsmParsers();
 
   // Initialize passes
   PassRegistry &Registry = *PassRegistry::getPassRegistry();
   initializeCore(Registry);
-  initializeCoroutines(Registry);
   initializeScalarOpts(Registry);
   initializeObjCARCOpts(Registry);
   initializeVectorization(Registry);
   initializeIPO(Registry);
   initializeAnalysis(Registry);
   initializeTransformUtils(Registry);
   initializeInstCombine(Registry);
   initializeAggressiveInstCombine(Registry);