From d57525294a6f9318db6aeda46bf77d004b836b43 Mon Sep 17 00:00:00 2001 From: Tyler Nowicki Date: Thu, 19 Sep 2024 14:06:43 -0400 Subject: [PATCH] [Coroutines] Refactor CoroShape::buildFrom for future use by ABI objects (#108623) * Refactor buildFrom to separate the analysis, abi related operations, cleaning and invalidating. * In a follow-up PR the code in initABI will be moved to an ABI object init method. * In a follow-up PR the OptimizeFrame flag will also be removed from the Shape and instead will be passed directly to buildCoroutineFrame (although it would be nice to find another way to trigger this optimization). This is the only thing that Shape cannot determine from the Function/Coroutine, but it is only needed within buildCoroutineFrame. See RFC for more info: https://discourse.llvm.org/t/rfc-abi-objects-for-coroutines/81057 --- llvm/lib/Transforms/Coroutines/CoroShape.h | 54 +++++- llvm/lib/Transforms/Coroutines/Coroutines.cpp | 154 ++++++++++-------- 2 files changed, 132 insertions(+), 76 deletions(-) diff --git a/llvm/lib/Transforms/Coroutines/CoroShape.h b/llvm/lib/Transforms/Coroutines/CoroShape.h index f5798b63bf7325..dcfe94ca076bd8 100644 --- a/llvm/lib/Transforms/Coroutines/CoroShape.h +++ b/llvm/lib/Transforms/Coroutines/CoroShape.h @@ -50,15 +50,45 @@ enum class ABI { // Holds structural Coroutine Intrinsics for a particular function and other // values used during CoroSplit pass. struct LLVM_LIBRARY_VISIBILITY Shape { - CoroBeginInst *CoroBegin; + CoroBeginInst *CoroBegin = nullptr; SmallVector CoroEnds; SmallVector CoroSizes; SmallVector CoroAligns; SmallVector CoroSuspends; - SmallVector SwiftErrorOps; SmallVector CoroAwaitSuspends; SmallVector SymmetricTransfers; + // Values invalidated by replaceSwiftErrorOps() + SmallVector SwiftErrorOps; + + void clear() { + CoroBegin = nullptr; + CoroEnds.clear(); + CoroSizes.clear(); + CoroAligns.clear(); + CoroSuspends.clear(); + CoroAwaitSuspends.clear(); + SymmetricTransfers.clear(); + + SwiftErrorOps.clear(); + + FrameTy = nullptr; + FramePtr = nullptr; + AllocaSpillBlock = nullptr; + } + + // Scan the function and collect the above intrinsics for later processing + void analyze(Function &F, SmallVectorImpl &CoroFrames, + SmallVectorImpl &UnusedCoroSaves); + // If for some reason, we were not able to find coro.begin, bailout. + void invalidateCoroutine(Function &F, + SmallVectorImpl &CoroFrames); + // Perform ABI related initial transformation + void initABI(); + // Remove orphaned and unnecessary intrinsics + void cleanCoroutine(SmallVectorImpl &CoroFrames, + SmallVectorImpl &UnusedCoroSaves); + // Field indexes for special fields in the switch lowering. struct SwitchFieldIndex { enum { @@ -76,11 +106,11 @@ struct LLVM_LIBRARY_VISIBILITY Shape { coro::ABI ABI; - StructType *FrameTy; + StructType *FrameTy = nullptr; Align FrameAlign; - uint64_t FrameSize; - Value *FramePtr; - BasicBlock *AllocaSpillBlock; + uint64_t FrameSize = 0; + Value *FramePtr = nullptr; + BasicBlock *AllocaSpillBlock = nullptr; /// This would only be true if optimization are enabled. bool OptimizeFrame; @@ -237,9 +267,17 @@ struct LLVM_LIBRARY_VISIBILITY Shape { Shape() = default; explicit Shape(Function &F, bool OptimizeFrame = false) : OptimizeFrame(OptimizeFrame) { - buildFrom(F); + SmallVector CoroFrames; + SmallVector UnusedCoroSaves; + + analyze(F, CoroFrames, UnusedCoroSaves); + if (!CoroBegin) { + invalidateCoroutine(F, CoroFrames); + return; + } + initABI(); + cleanCoroutine(CoroFrames, UnusedCoroSaves); } - void buildFrom(Function &F); }; } // end namespace coro diff --git a/llvm/lib/Transforms/Coroutines/Coroutines.cpp b/llvm/lib/Transforms/Coroutines/Coroutines.cpp index 5cc13a584aef32..ef0abd2d823bbd 100644 --- a/llvm/lib/Transforms/Coroutines/Coroutines.cpp +++ b/llvm/lib/Transforms/Coroutines/Coroutines.cpp @@ -177,17 +177,6 @@ void coro::suppressCoroAllocs(LLVMContext &Context, } } -static void clear(coro::Shape &Shape) { - Shape.CoroBegin = nullptr; - Shape.CoroEnds.clear(); - Shape.CoroSizes.clear(); - Shape.CoroSuspends.clear(); - - Shape.FrameTy = nullptr; - Shape.FramePtr = nullptr; - Shape.AllocaSpillBlock = nullptr; -} - static CoroSaveInst *createCoroSave(CoroBeginInst *CoroBegin, CoroSuspendInst *SuspendInst) { Module *M = SuspendInst->getModule(); @@ -200,13 +189,14 @@ static CoroSaveInst *createCoroSave(CoroBeginInst *CoroBegin, } // Collect "interesting" coroutine intrinsics. -void coro::Shape::buildFrom(Function &F) { +void coro::Shape::analyze(Function &F, + SmallVectorImpl &CoroFrames, + SmallVectorImpl &UnusedCoroSaves) { + clear(); + bool HasFinalSuspend = false; bool HasUnwindCoroEnd = false; size_t FinalSuspendIndex = 0; - clear(*this); - SmallVector CoroFrames; - SmallVector UnusedCoroSaves; for (Instruction &I : instructions(F)) { // FIXME: coro_await_suspend_* are not proper `IntrinisicInst`s @@ -298,8 +288,65 @@ void coro::Shape::buildFrom(Function &F) { } } - // If for some reason, we were not able to find coro.begin, bailout. - if (!CoroBegin) { + // If there is no CoroBegin then this is not a coroutine. + if (!CoroBegin) + return; + + // Determination of ABI and initializing lowering info + auto Id = CoroBegin->getId(); + switch (auto IntrID = Id->getIntrinsicID()) { + case Intrinsic::coro_id: { + ABI = coro::ABI::Switch; + SwitchLowering.HasFinalSuspend = HasFinalSuspend; + SwitchLowering.HasUnwindCoroEnd = HasUnwindCoroEnd; + + auto SwitchId = getSwitchCoroId(); + SwitchLowering.ResumeSwitch = nullptr; + SwitchLowering.PromiseAlloca = SwitchId->getPromise(); + SwitchLowering.ResumeEntryBlock = nullptr; + + // Move final suspend to the last element in the CoroSuspends vector. + if (SwitchLowering.HasFinalSuspend && + FinalSuspendIndex != CoroSuspends.size() - 1) + std::swap(CoroSuspends[FinalSuspendIndex], CoroSuspends.back()); + break; + } + case Intrinsic::coro_id_async: { + ABI = coro::ABI::Async; + auto *AsyncId = getAsyncCoroId(); + AsyncId->checkWellFormed(); + AsyncLowering.Context = AsyncId->getStorage(); + AsyncLowering.ContextArgNo = AsyncId->getStorageArgumentIndex(); + AsyncLowering.ContextHeaderSize = AsyncId->getStorageSize(); + AsyncLowering.ContextAlignment = AsyncId->getStorageAlignment().value(); + AsyncLowering.AsyncFuncPointer = AsyncId->getAsyncFunctionPointer(); + AsyncLowering.AsyncCC = F.getCallingConv(); + break; + } + case Intrinsic::coro_id_retcon: + case Intrinsic::coro_id_retcon_once: { + ABI = IntrID == Intrinsic::coro_id_retcon ? coro::ABI::Retcon + : coro::ABI::RetconOnce; + auto ContinuationId = getRetconCoroId(); + ContinuationId->checkWellFormed(); + auto Prototype = ContinuationId->getPrototype(); + RetconLowering.ResumePrototype = Prototype; + RetconLowering.Alloc = ContinuationId->getAllocFunction(); + RetconLowering.Dealloc = ContinuationId->getDeallocFunction(); + RetconLowering.ReturnBlock = nullptr; + RetconLowering.IsFrameInlineInStorage = false; + break; + } + default: + llvm_unreachable("coro.begin is not dependent on a coro.id call"); + } +} + +// If for some reason, we were not able to find coro.begin, bailout. +void coro::Shape::invalidateCoroutine( + Function &F, SmallVectorImpl &CoroFrames) { + assert(!CoroBegin); + { // Replace coro.frame which are supposed to be lowered to the result of // coro.begin with undef. auto *Undef = UndefValue::get(PointerType::get(F.getContext(), 0)); @@ -307,6 +354,7 @@ void coro::Shape::buildFrom(Function &F) { CF->replaceAllUsesWith(Undef); CF->eraseFromParent(); } + CoroFrames.clear(); // Replace all coro.suspend with undef and remove related coro.saves if // present. @@ -316,25 +364,18 @@ void coro::Shape::buildFrom(Function &F) { if (auto *CoroSave = CS->getCoroSave()) CoroSave->eraseFromParent(); } + CoroSuspends.clear(); // Replace all coro.ends with unreachable instruction. for (AnyCoroEndInst *CE : CoroEnds) changeToUnreachable(CE); - - return; } +} - auto Id = CoroBegin->getId(); - switch (auto IdIntrinsic = Id->getIntrinsicID()) { - case Intrinsic::coro_id: { - auto SwitchId = cast(Id); - this->ABI = coro::ABI::Switch; - this->SwitchLowering.HasFinalSuspend = HasFinalSuspend; - this->SwitchLowering.HasUnwindCoroEnd = HasUnwindCoroEnd; - this->SwitchLowering.ResumeSwitch = nullptr; - this->SwitchLowering.PromiseAlloca = SwitchId->getPromise(); - this->SwitchLowering.ResumeEntryBlock = nullptr; - +// Perform semantic checking and initialization of the ABI +void coro::Shape::initABI() { + switch (ABI) { + case coro::ABI::Switch: { for (auto *AnySuspend : CoroSuspends) { auto Suspend = dyn_cast(AnySuspend); if (!Suspend) { @@ -349,33 +390,11 @@ void coro::Shape::buildFrom(Function &F) { } break; } - case Intrinsic::coro_id_async: { - auto *AsyncId = cast(Id); - AsyncId->checkWellFormed(); - this->ABI = coro::ABI::Async; - this->AsyncLowering.Context = AsyncId->getStorage(); - this->AsyncLowering.ContextArgNo = AsyncId->getStorageArgumentIndex(); - this->AsyncLowering.ContextHeaderSize = AsyncId->getStorageSize(); - this->AsyncLowering.ContextAlignment = - AsyncId->getStorageAlignment().value(); - this->AsyncLowering.AsyncFuncPointer = AsyncId->getAsyncFunctionPointer(); - this->AsyncLowering.AsyncCC = F.getCallingConv(); + case coro::ABI::Async: { break; }; - case Intrinsic::coro_id_retcon: - case Intrinsic::coro_id_retcon_once: { - auto ContinuationId = cast(Id); - ContinuationId->checkWellFormed(); - this->ABI = (IdIntrinsic == Intrinsic::coro_id_retcon - ? coro::ABI::Retcon - : coro::ABI::RetconOnce); - auto Prototype = ContinuationId->getPrototype(); - this->RetconLowering.ResumePrototype = Prototype; - this->RetconLowering.Alloc = ContinuationId->getAllocFunction(); - this->RetconLowering.Dealloc = ContinuationId->getDeallocFunction(); - this->RetconLowering.ReturnBlock = nullptr; - this->RetconLowering.IsFrameInlineInStorage = false; - + case coro::ABI::Retcon: + case coro::ABI::RetconOnce: { // Determine the result value types, and make sure they match up with // the values passed to the suspends. auto ResultTys = getRetconResultTypes(); @@ -408,7 +427,7 @@ void coro::Shape::buildFrom(Function &F) { #ifndef NDEBUG Suspend->dump(); - Prototype->getFunctionType()->dump(); + RetconLowering.ResumePrototype->getFunctionType()->dump(); #endif report_fatal_error("argument to coro.suspend.retcon does not " "match corresponding prototype function result"); @@ -417,14 +436,14 @@ void coro::Shape::buildFrom(Function &F) { if (SI != SE || RI != RE) { #ifndef NDEBUG Suspend->dump(); - Prototype->getFunctionType()->dump(); + RetconLowering.ResumePrototype->getFunctionType()->dump(); #endif report_fatal_error("wrong number of arguments to coro.suspend.retcon"); } // Check that the result type of the suspend matches the resume types. Type *SResultTy = Suspend->getType(); - ArrayRef SuspendResultTys; + ArrayRef SuspendResultTys; if (SResultTy->isVoidTy()) { // leave as empty array } else if (auto SResultStructTy = dyn_cast(SResultTy)) { @@ -436,7 +455,7 @@ void coro::Shape::buildFrom(Function &F) { if (SuspendResultTys.size() != ResumeTys.size()) { #ifndef NDEBUG Suspend->dump(); - Prototype->getFunctionType()->dump(); + RetconLowering.ResumePrototype->getFunctionType()->dump(); #endif report_fatal_error("wrong number of results from coro.suspend.retcon"); } @@ -444,7 +463,7 @@ void coro::Shape::buildFrom(Function &F) { if (SuspendResultTys[I] != ResumeTys[I]) { #ifndef NDEBUG Suspend->dump(); - Prototype->getFunctionType()->dump(); + RetconLowering.ResumePrototype->getFunctionType()->dump(); #endif report_fatal_error("result from coro.suspend.retcon does not " "match corresponding prototype function param"); @@ -453,26 +472,25 @@ void coro::Shape::buildFrom(Function &F) { } break; } - default: llvm_unreachable("coro.begin is not dependent on a coro.id call"); } +} - // The coro.free intrinsic is always lowered to the result of coro.begin. +void coro::Shape::cleanCoroutine( + SmallVectorImpl &CoroFrames, + SmallVectorImpl &UnusedCoroSaves) { + // The coro.frame intrinsic is always lowered to the result of coro.begin. for (CoroFrameInst *CF : CoroFrames) { CF->replaceAllUsesWith(CoroBegin); CF->eraseFromParent(); } - - // Move final suspend to be the last element in the CoroSuspends vector. - if (ABI == coro::ABI::Switch && - SwitchLowering.HasFinalSuspend && - FinalSuspendIndex != CoroSuspends.size() - 1) - std::swap(CoroSuspends[FinalSuspendIndex], CoroSuspends.back()); + CoroFrames.clear(); // Remove orphaned coro.saves. for (CoroSaveInst *CoroSave : UnusedCoroSaves) CoroSave->eraseFromParent(); + UnusedCoroSaves.clear(); } static void propagateCallAttrsFromCallee(CallInst *Call, Function *Callee) {