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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGAtomic.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGAtomic.cpp | 1787 |
1 files changed, 1787 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGAtomic.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGAtomic.cpp new file mode 100644 index 0000000..da82249 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGAtomic.cpp @@ -0,0 +1,1787 @@ +//===--- CGAtomic.cpp - Emit LLVM IR for atomic operations ----------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file contains the code for emitting atomic operations. +// +//===----------------------------------------------------------------------===// + +#include "CodeGenFunction.h" +#include "CGCall.h" +#include "CGRecordLayout.h" +#include "CodeGenModule.h" +#include "clang/AST/ASTContext.h" +#include "clang/CodeGen/CGFunctionInfo.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/Operator.h" + +using namespace clang; +using namespace CodeGen; + +namespace { + class AtomicInfo { + CodeGenFunction &CGF; + QualType AtomicTy; + QualType ValueTy; + uint64_t AtomicSizeInBits; + uint64_t ValueSizeInBits; + CharUnits AtomicAlign; + CharUnits ValueAlign; + CharUnits LValueAlign; + TypeEvaluationKind EvaluationKind; + bool UseLibcall; + LValue LVal; + CGBitFieldInfo BFI; + public: + AtomicInfo(CodeGenFunction &CGF, LValue &lvalue) + : CGF(CGF), AtomicSizeInBits(0), ValueSizeInBits(0), + EvaluationKind(TEK_Scalar), UseLibcall(true) { + assert(!lvalue.isGlobalReg()); + ASTContext &C = CGF.getContext(); + if (lvalue.isSimple()) { + AtomicTy = lvalue.getType(); + if (auto *ATy = AtomicTy->getAs<AtomicType>()) + ValueTy = ATy->getValueType(); + else + ValueTy = AtomicTy; + EvaluationKind = CGF.getEvaluationKind(ValueTy); + + uint64_t ValueAlignInBits; + uint64_t AtomicAlignInBits; + TypeInfo ValueTI = C.getTypeInfo(ValueTy); + ValueSizeInBits = ValueTI.Width; + ValueAlignInBits = ValueTI.Align; + + TypeInfo AtomicTI = C.getTypeInfo(AtomicTy); + AtomicSizeInBits = AtomicTI.Width; + AtomicAlignInBits = AtomicTI.Align; + + assert(ValueSizeInBits <= AtomicSizeInBits); + assert(ValueAlignInBits <= AtomicAlignInBits); + + AtomicAlign = C.toCharUnitsFromBits(AtomicAlignInBits); + ValueAlign = C.toCharUnitsFromBits(ValueAlignInBits); + if (lvalue.getAlignment().isZero()) + lvalue.setAlignment(AtomicAlign); + + LVal = lvalue; + } else if (lvalue.isBitField()) { + ValueTy = lvalue.getType(); + ValueSizeInBits = C.getTypeSize(ValueTy); + auto &OrigBFI = lvalue.getBitFieldInfo(); + auto Offset = OrigBFI.Offset % C.toBits(lvalue.getAlignment()); + AtomicSizeInBits = C.toBits( + C.toCharUnitsFromBits(Offset + OrigBFI.Size + C.getCharWidth() - 1) + .RoundUpToAlignment(lvalue.getAlignment())); + auto VoidPtrAddr = CGF.EmitCastToVoidPtr(lvalue.getBitFieldAddr()); + auto OffsetInChars = + (C.toCharUnitsFromBits(OrigBFI.Offset) / lvalue.getAlignment()) * + lvalue.getAlignment(); + VoidPtrAddr = CGF.Builder.CreateConstGEP1_64( + VoidPtrAddr, OffsetInChars.getQuantity()); + auto Addr = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast( + VoidPtrAddr, + CGF.Builder.getIntNTy(AtomicSizeInBits)->getPointerTo(), + "atomic_bitfield_base"); + BFI = OrigBFI; + BFI.Offset = Offset; + BFI.StorageSize = AtomicSizeInBits; + LVal = LValue::MakeBitfield(Addr, BFI, lvalue.getType(), + lvalue.getAlignment()); + LVal.setTBAAInfo(lvalue.getTBAAInfo()); + AtomicTy = C.getIntTypeForBitwidth(AtomicSizeInBits, OrigBFI.IsSigned); + if (AtomicTy.isNull()) { + llvm::APInt Size( + /*numBits=*/32, + C.toCharUnitsFromBits(AtomicSizeInBits).getQuantity()); + AtomicTy = C.getConstantArrayType(C.CharTy, Size, ArrayType::Normal, + /*IndexTypeQuals=*/0); + } + AtomicAlign = ValueAlign = lvalue.getAlignment(); + } else if (lvalue.isVectorElt()) { + ValueTy = lvalue.getType()->getAs<VectorType>()->getElementType(); + ValueSizeInBits = C.getTypeSize(ValueTy); + AtomicTy = lvalue.getType(); + AtomicSizeInBits = C.getTypeSize(AtomicTy); + AtomicAlign = ValueAlign = lvalue.getAlignment(); + LVal = lvalue; + } else { + assert(lvalue.isExtVectorElt()); + ValueTy = lvalue.getType(); + ValueSizeInBits = C.getTypeSize(ValueTy); + AtomicTy = ValueTy = CGF.getContext().getExtVectorType( + lvalue.getType(), lvalue.getExtVectorAddr() + ->getType() + ->getPointerElementType() + ->getVectorNumElements()); + AtomicSizeInBits = C.getTypeSize(AtomicTy); + AtomicAlign = ValueAlign = lvalue.getAlignment(); + LVal = lvalue; + } + UseLibcall = !C.getTargetInfo().hasBuiltinAtomic( + AtomicSizeInBits, C.toBits(lvalue.getAlignment())); + } + + QualType getAtomicType() const { return AtomicTy; } + QualType getValueType() const { return ValueTy; } + CharUnits getAtomicAlignment() const { return AtomicAlign; } + CharUnits getValueAlignment() const { return ValueAlign; } + uint64_t getAtomicSizeInBits() const { return AtomicSizeInBits; } + uint64_t getValueSizeInBits() const { return ValueSizeInBits; } + TypeEvaluationKind getEvaluationKind() const { return EvaluationKind; } + bool shouldUseLibcall() const { return UseLibcall; } + const LValue &getAtomicLValue() const { return LVal; } + llvm::Value *getAtomicAddress() const { + if (LVal.isSimple()) + return LVal.getAddress(); + else if (LVal.isBitField()) + return LVal.getBitFieldAddr(); + else if (LVal.isVectorElt()) + return LVal.getVectorAddr(); + assert(LVal.isExtVectorElt()); + return LVal.getExtVectorAddr(); + } + + /// Is the atomic size larger than the underlying value type? + /// + /// Note that the absence of padding does not mean that atomic + /// objects are completely interchangeable with non-atomic + /// objects: we might have promoted the alignment of a type + /// without making it bigger. + bool hasPadding() const { + return (ValueSizeInBits != AtomicSizeInBits); + } + + bool emitMemSetZeroIfNecessary() const; + + llvm::Value *getAtomicSizeValue() const { + CharUnits size = CGF.getContext().toCharUnitsFromBits(AtomicSizeInBits); + return CGF.CGM.getSize(size); + } + + /// Cast the given pointer to an integer pointer suitable for + /// atomic operations. + llvm::Value *emitCastToAtomicIntPointer(llvm::Value *addr) const; + + /// Turn an atomic-layout object into an r-value. + RValue convertTempToRValue(llvm::Value *addr, AggValueSlot resultSlot, + SourceLocation loc, bool AsValue) const; + + /// \brief Converts a rvalue to integer value. + llvm::Value *convertRValueToInt(RValue RVal) const; + + RValue ConvertIntToValueOrAtomic(llvm::Value *IntVal, + AggValueSlot ResultSlot, + SourceLocation Loc, bool AsValue) const; + + /// Copy an atomic r-value into atomic-layout memory. + void emitCopyIntoMemory(RValue rvalue) const; + + /// Project an l-value down to the value field. + LValue projectValue() const { + assert(LVal.isSimple()); + llvm::Value *addr = getAtomicAddress(); + if (hasPadding()) + addr = CGF.Builder.CreateStructGEP(nullptr, addr, 0); + + return LValue::MakeAddr(addr, getValueType(), LVal.getAlignment(), + CGF.getContext(), LVal.getTBAAInfo()); + } + + /// \brief Emits atomic load. + /// \returns Loaded value. + RValue EmitAtomicLoad(AggValueSlot ResultSlot, SourceLocation Loc, + bool AsValue, llvm::AtomicOrdering AO, + bool IsVolatile); + + /// \brief Emits atomic compare-and-exchange sequence. + /// \param Expected Expected value. + /// \param Desired Desired value. + /// \param Success Atomic ordering for success operation. + /// \param Failure Atomic ordering for failed operation. + /// \param IsWeak true if atomic operation is weak, false otherwise. + /// \returns Pair of values: previous value from storage (value type) and + /// boolean flag (i1 type) with true if success and false otherwise. + std::pair<RValue, llvm::Value *> EmitAtomicCompareExchange( + RValue Expected, RValue Desired, + llvm::AtomicOrdering Success = llvm::SequentiallyConsistent, + llvm::AtomicOrdering Failure = llvm::SequentiallyConsistent, + bool IsWeak = false); + + /// \brief Emits atomic update. + /// \param AO Atomic ordering. + /// \param UpdateOp Update operation for the current lvalue. + void EmitAtomicUpdate(llvm::AtomicOrdering AO, + const llvm::function_ref<RValue(RValue)> &UpdateOp, + bool IsVolatile); + /// \brief Emits atomic update. + /// \param AO Atomic ordering. + void EmitAtomicUpdate(llvm::AtomicOrdering AO, RValue UpdateRVal, + bool IsVolatile); + + /// Materialize an atomic r-value in atomic-layout memory. + llvm::Value *materializeRValue(RValue rvalue) const; + + /// \brief Translates LLVM atomic ordering to GNU atomic ordering for + /// libcalls. + static AtomicExpr::AtomicOrderingKind + translateAtomicOrdering(const llvm::AtomicOrdering AO); + + private: + bool requiresMemSetZero(llvm::Type *type) const; + + /// \brief Creates temp alloca for intermediate operations on atomic value. + llvm::Value *CreateTempAlloca() const; + + /// \brief Emits atomic load as a libcall. + void EmitAtomicLoadLibcall(llvm::Value *AddForLoaded, + llvm::AtomicOrdering AO, bool IsVolatile); + /// \brief Emits atomic load as LLVM instruction. + llvm::Value *EmitAtomicLoadOp(llvm::AtomicOrdering AO, bool IsVolatile); + /// \brief Emits atomic compare-and-exchange op as a libcall. + llvm::Value *EmitAtomicCompareExchangeLibcall( + llvm::Value *ExpectedAddr, llvm::Value *DesiredAddr, + llvm::AtomicOrdering Success = llvm::SequentiallyConsistent, + llvm::AtomicOrdering Failure = llvm::SequentiallyConsistent); + /// \brief Emits atomic compare-and-exchange op as LLVM instruction. + std::pair<llvm::Value *, llvm::Value *> EmitAtomicCompareExchangeOp( + llvm::Value *ExpectedVal, llvm::Value *DesiredVal, + llvm::AtomicOrdering Success = llvm::SequentiallyConsistent, + llvm::AtomicOrdering Failure = llvm::SequentiallyConsistent, + bool IsWeak = false); + /// \brief Emit atomic update as libcalls. + void + EmitAtomicUpdateLibcall(llvm::AtomicOrdering AO, + const llvm::function_ref<RValue(RValue)> &UpdateOp, + bool IsVolatile); + /// \brief Emit atomic update as LLVM instructions. + void EmitAtomicUpdateOp(llvm::AtomicOrdering AO, + const llvm::function_ref<RValue(RValue)> &UpdateOp, + bool IsVolatile); + /// \brief Emit atomic update as libcalls. + void EmitAtomicUpdateLibcall(llvm::AtomicOrdering AO, RValue UpdateRVal, + bool IsVolatile); + /// \brief Emit atomic update as LLVM instructions. + void EmitAtomicUpdateOp(llvm::AtomicOrdering AO, RValue UpdateRal, + bool IsVolatile); + }; +} + +AtomicExpr::AtomicOrderingKind +AtomicInfo::translateAtomicOrdering(const llvm::AtomicOrdering AO) { + switch (AO) { + case llvm::Unordered: + case llvm::NotAtomic: + case llvm::Monotonic: + return AtomicExpr::AO_ABI_memory_order_relaxed; + case llvm::Acquire: + return AtomicExpr::AO_ABI_memory_order_acquire; + case llvm::Release: + return AtomicExpr::AO_ABI_memory_order_release; + case llvm::AcquireRelease: + return AtomicExpr::AO_ABI_memory_order_acq_rel; + case llvm::SequentiallyConsistent: + return AtomicExpr::AO_ABI_memory_order_seq_cst; + } + llvm_unreachable("Unhandled AtomicOrdering"); +} + +llvm::Value *AtomicInfo::CreateTempAlloca() const { + auto *TempAlloca = CGF.CreateMemTemp( + (LVal.isBitField() && ValueSizeInBits > AtomicSizeInBits) ? ValueTy + : AtomicTy, + "atomic-temp"); + TempAlloca->setAlignment(getAtomicAlignment().getQuantity()); + // Cast to pointer to value type for bitfields. + if (LVal.isBitField()) + return CGF.Builder.CreatePointerBitCastOrAddrSpaceCast( + TempAlloca, getAtomicAddress()->getType()); + return TempAlloca; +} + +static RValue emitAtomicLibcall(CodeGenFunction &CGF, + StringRef fnName, + QualType resultType, + CallArgList &args) { + const CGFunctionInfo &fnInfo = + CGF.CGM.getTypes().arrangeFreeFunctionCall(resultType, args, + FunctionType::ExtInfo(), RequiredArgs::All); + llvm::FunctionType *fnTy = CGF.CGM.getTypes().GetFunctionType(fnInfo); + llvm::Constant *fn = CGF.CGM.CreateRuntimeFunction(fnTy, fnName); + return CGF.EmitCall(fnInfo, fn, ReturnValueSlot(), args); +} + +/// Does a store of the given IR type modify the full expected width? +static bool isFullSizeType(CodeGenModule &CGM, llvm::Type *type, + uint64_t expectedSize) { + return (CGM.getDataLayout().getTypeStoreSize(type) * 8 == expectedSize); +} + +/// Does the atomic type require memsetting to zero before initialization? +/// +/// The IR type is provided as a way of making certain queries faster. +bool AtomicInfo::requiresMemSetZero(llvm::Type *type) const { + // If the atomic type has size padding, we definitely need a memset. + if (hasPadding()) return true; + + // Otherwise, do some simple heuristics to try to avoid it: + switch (getEvaluationKind()) { + // For scalars and complexes, check whether the store size of the + // type uses the full size. + case TEK_Scalar: + return !isFullSizeType(CGF.CGM, type, AtomicSizeInBits); + case TEK_Complex: + return !isFullSizeType(CGF.CGM, type->getStructElementType(0), + AtomicSizeInBits / 2); + + // Padding in structs has an undefined bit pattern. User beware. + case TEK_Aggregate: + return false; + } + llvm_unreachable("bad evaluation kind"); +} + +bool AtomicInfo::emitMemSetZeroIfNecessary() const { + assert(LVal.isSimple()); + llvm::Value *addr = LVal.getAddress(); + if (!requiresMemSetZero(addr->getType()->getPointerElementType())) + return false; + + CGF.Builder.CreateMemSet( + addr, llvm::ConstantInt::get(CGF.Int8Ty, 0), + CGF.getContext().toCharUnitsFromBits(AtomicSizeInBits).getQuantity(), + LVal.getAlignment().getQuantity()); + return true; +} + +static void emitAtomicCmpXchg(CodeGenFunction &CGF, AtomicExpr *E, bool IsWeak, + llvm::Value *Dest, llvm::Value *Ptr, + llvm::Value *Val1, llvm::Value *Val2, + uint64_t Size, unsigned Align, + llvm::AtomicOrdering SuccessOrder, + llvm::AtomicOrdering FailureOrder) { + // Note that cmpxchg doesn't support weak cmpxchg, at least at the moment. + llvm::LoadInst *Expected = CGF.Builder.CreateLoad(Val1); + Expected->setAlignment(Align); + llvm::LoadInst *Desired = CGF.Builder.CreateLoad(Val2); + Desired->setAlignment(Align); + + llvm::AtomicCmpXchgInst *Pair = CGF.Builder.CreateAtomicCmpXchg( + Ptr, Expected, Desired, SuccessOrder, FailureOrder); + Pair->setVolatile(E->isVolatile()); + Pair->setWeak(IsWeak); + + // Cmp holds the result of the compare-exchange operation: true on success, + // false on failure. + llvm::Value *Old = CGF.Builder.CreateExtractValue(Pair, 0); + llvm::Value *Cmp = CGF.Builder.CreateExtractValue(Pair, 1); + + // This basic block is used to hold the store instruction if the operation + // failed. + llvm::BasicBlock *StoreExpectedBB = + CGF.createBasicBlock("cmpxchg.store_expected", CGF.CurFn); + + // This basic block is the exit point of the operation, we should end up + // here regardless of whether or not the operation succeeded. + llvm::BasicBlock *ContinueBB = + CGF.createBasicBlock("cmpxchg.continue", CGF.CurFn); + + // Update Expected if Expected isn't equal to Old, otherwise branch to the + // exit point. + CGF.Builder.CreateCondBr(Cmp, ContinueBB, StoreExpectedBB); + + CGF.Builder.SetInsertPoint(StoreExpectedBB); + // Update the memory at Expected with Old's value. + llvm::StoreInst *StoreExpected = CGF.Builder.CreateStore(Old, Val1); + StoreExpected->setAlignment(Align); + // Finally, branch to the exit point. + CGF.Builder.CreateBr(ContinueBB); + + CGF.Builder.SetInsertPoint(ContinueBB); + // Update the memory at Dest with Cmp's value. + CGF.EmitStoreOfScalar(Cmp, CGF.MakeAddrLValue(Dest, E->getType())); + return; +} + +/// Given an ordering required on success, emit all possible cmpxchg +/// instructions to cope with the provided (but possibly only dynamically known) +/// FailureOrder. +static void emitAtomicCmpXchgFailureSet(CodeGenFunction &CGF, AtomicExpr *E, + bool IsWeak, llvm::Value *Dest, + llvm::Value *Ptr, llvm::Value *Val1, + llvm::Value *Val2, + llvm::Value *FailureOrderVal, + uint64_t Size, unsigned Align, + llvm::AtomicOrdering SuccessOrder) { + llvm::AtomicOrdering FailureOrder; + if (llvm::ConstantInt *FO = dyn_cast<llvm::ConstantInt>(FailureOrderVal)) { + switch (FO->getSExtValue()) { + default: + FailureOrder = llvm::Monotonic; + break; + case AtomicExpr::AO_ABI_memory_order_consume: + case AtomicExpr::AO_ABI_memory_order_acquire: + FailureOrder = llvm::Acquire; + break; + case AtomicExpr::AO_ABI_memory_order_seq_cst: + FailureOrder = llvm::SequentiallyConsistent; + break; + } + if (FailureOrder >= SuccessOrder) { + // Don't assert on undefined behaviour. + FailureOrder = + llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(SuccessOrder); + } + emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, Size, Align, + SuccessOrder, FailureOrder); + return; + } + + // Create all the relevant BB's + llvm::BasicBlock *MonotonicBB = nullptr, *AcquireBB = nullptr, + *SeqCstBB = nullptr; + MonotonicBB = CGF.createBasicBlock("monotonic_fail", CGF.CurFn); + if (SuccessOrder != llvm::Monotonic && SuccessOrder != llvm::Release) + AcquireBB = CGF.createBasicBlock("acquire_fail", CGF.CurFn); + if (SuccessOrder == llvm::SequentiallyConsistent) + SeqCstBB = CGF.createBasicBlock("seqcst_fail", CGF.CurFn); + + llvm::BasicBlock *ContBB = CGF.createBasicBlock("atomic.continue", CGF.CurFn); + + llvm::SwitchInst *SI = CGF.Builder.CreateSwitch(FailureOrderVal, MonotonicBB); + + // Emit all the different atomics + + // MonotonicBB is arbitrarily chosen as the default case; in practice, this + // doesn't matter unless someone is crazy enough to use something that + // doesn't fold to a constant for the ordering. + CGF.Builder.SetInsertPoint(MonotonicBB); + emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, + Size, Align, SuccessOrder, llvm::Monotonic); + CGF.Builder.CreateBr(ContBB); + + if (AcquireBB) { + CGF.Builder.SetInsertPoint(AcquireBB); + emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, + Size, Align, SuccessOrder, llvm::Acquire); + CGF.Builder.CreateBr(ContBB); + SI->addCase(CGF.Builder.getInt32(AtomicExpr::AO_ABI_memory_order_consume), + AcquireBB); + SI->addCase(CGF.Builder.getInt32(AtomicExpr::AO_ABI_memory_order_acquire), + AcquireBB); + } + if (SeqCstBB) { + CGF.Builder.SetInsertPoint(SeqCstBB); + emitAtomicCmpXchg(CGF, E, IsWeak, Dest, Ptr, Val1, Val2, + Size, Align, SuccessOrder, llvm::SequentiallyConsistent); + CGF.Builder.CreateBr(ContBB); + SI->addCase(CGF.Builder.getInt32(AtomicExpr::AO_ABI_memory_order_seq_cst), + SeqCstBB); + } + + CGF.Builder.SetInsertPoint(ContBB); +} + +static void EmitAtomicOp(CodeGenFunction &CGF, AtomicExpr *E, llvm::Value *Dest, + llvm::Value *Ptr, llvm::Value *Val1, llvm::Value *Val2, + llvm::Value *IsWeak, llvm::Value *FailureOrder, + uint64_t Size, unsigned Align, + llvm::AtomicOrdering Order) { + llvm::AtomicRMWInst::BinOp Op = llvm::AtomicRMWInst::Add; + llvm::Instruction::BinaryOps PostOp = (llvm::Instruction::BinaryOps)0; + + switch (E->getOp()) { + case AtomicExpr::AO__c11_atomic_init: + llvm_unreachable("Already handled!"); + + case AtomicExpr::AO__c11_atomic_compare_exchange_strong: + emitAtomicCmpXchgFailureSet(CGF, E, false, Dest, Ptr, Val1, Val2, + FailureOrder, Size, Align, Order); + return; + case AtomicExpr::AO__c11_atomic_compare_exchange_weak: + emitAtomicCmpXchgFailureSet(CGF, E, true, Dest, Ptr, Val1, Val2, + FailureOrder, Size, Align, Order); + return; + case AtomicExpr::AO__atomic_compare_exchange: + case AtomicExpr::AO__atomic_compare_exchange_n: { + if (llvm::ConstantInt *IsWeakC = dyn_cast<llvm::ConstantInt>(IsWeak)) { + emitAtomicCmpXchgFailureSet(CGF, E, IsWeakC->getZExtValue(), Dest, Ptr, + Val1, Val2, FailureOrder, Size, Align, Order); + } else { + // Create all the relevant BB's + llvm::BasicBlock *StrongBB = + CGF.createBasicBlock("cmpxchg.strong", CGF.CurFn); + llvm::BasicBlock *WeakBB = CGF.createBasicBlock("cmxchg.weak", CGF.CurFn); + llvm::BasicBlock *ContBB = + CGF.createBasicBlock("cmpxchg.continue", CGF.CurFn); + + llvm::SwitchInst *SI = CGF.Builder.CreateSwitch(IsWeak, WeakBB); + SI->addCase(CGF.Builder.getInt1(false), StrongBB); + + CGF.Builder.SetInsertPoint(StrongBB); + emitAtomicCmpXchgFailureSet(CGF, E, false, Dest, Ptr, Val1, Val2, + FailureOrder, Size, Align, Order); + CGF.Builder.CreateBr(ContBB); + + CGF.Builder.SetInsertPoint(WeakBB); + emitAtomicCmpXchgFailureSet(CGF, E, true, Dest, Ptr, Val1, Val2, + FailureOrder, Size, Align, Order); + CGF.Builder.CreateBr(ContBB); + + CGF.Builder.SetInsertPoint(ContBB); + } + return; + } + case AtomicExpr::AO__c11_atomic_load: + case AtomicExpr::AO__atomic_load_n: + case AtomicExpr::AO__atomic_load: { + llvm::LoadInst *Load = CGF.Builder.CreateLoad(Ptr); + Load->setAtomic(Order); + Load->setAlignment(Size); + Load->setVolatile(E->isVolatile()); + llvm::StoreInst *StoreDest = CGF.Builder.CreateStore(Load, Dest); + StoreDest->setAlignment(Align); + return; + } + + case AtomicExpr::AO__c11_atomic_store: + case AtomicExpr::AO__atomic_store: + case AtomicExpr::AO__atomic_store_n: { + assert(!Dest && "Store does not return a value"); + llvm::LoadInst *LoadVal1 = CGF.Builder.CreateLoad(Val1); + LoadVal1->setAlignment(Align); + llvm::StoreInst *Store = CGF.Builder.CreateStore(LoadVal1, Ptr); + Store->setAtomic(Order); + Store->setAlignment(Size); + Store->setVolatile(E->isVolatile()); + return; + } + + case AtomicExpr::AO__c11_atomic_exchange: + case AtomicExpr::AO__atomic_exchange_n: + case AtomicExpr::AO__atomic_exchange: + Op = llvm::AtomicRMWInst::Xchg; + break; + + case AtomicExpr::AO__atomic_add_fetch: + PostOp = llvm::Instruction::Add; + // Fall through. + case AtomicExpr::AO__c11_atomic_fetch_add: + case AtomicExpr::AO__atomic_fetch_add: + Op = llvm::AtomicRMWInst::Add; + break; + + case AtomicExpr::AO__atomic_sub_fetch: + PostOp = llvm::Instruction::Sub; + // Fall through. + case AtomicExpr::AO__c11_atomic_fetch_sub: + case AtomicExpr::AO__atomic_fetch_sub: + Op = llvm::AtomicRMWInst::Sub; + break; + + case AtomicExpr::AO__atomic_and_fetch: + PostOp = llvm::Instruction::And; + // Fall through. + case AtomicExpr::AO__c11_atomic_fetch_and: + case AtomicExpr::AO__atomic_fetch_and: + Op = llvm::AtomicRMWInst::And; + break; + + case AtomicExpr::AO__atomic_or_fetch: + PostOp = llvm::Instruction::Or; + // Fall through. + case AtomicExpr::AO__c11_atomic_fetch_or: + case AtomicExpr::AO__atomic_fetch_or: + Op = llvm::AtomicRMWInst::Or; + break; + + case AtomicExpr::AO__atomic_xor_fetch: + PostOp = llvm::Instruction::Xor; + // Fall through. + case AtomicExpr::AO__c11_atomic_fetch_xor: + case AtomicExpr::AO__atomic_fetch_xor: + Op = llvm::AtomicRMWInst::Xor; + break; + + case AtomicExpr::AO__atomic_nand_fetch: + PostOp = llvm::Instruction::And; + // Fall through. + case AtomicExpr::AO__atomic_fetch_nand: + Op = llvm::AtomicRMWInst::Nand; + break; + } + + llvm::LoadInst *LoadVal1 = CGF.Builder.CreateLoad(Val1); + LoadVal1->setAlignment(Align); + llvm::AtomicRMWInst *RMWI = + CGF.Builder.CreateAtomicRMW(Op, Ptr, LoadVal1, Order); + RMWI->setVolatile(E->isVolatile()); + + // For __atomic_*_fetch operations, perform the operation again to + // determine the value which was written. + llvm::Value *Result = RMWI; + if (PostOp) + Result = CGF.Builder.CreateBinOp(PostOp, RMWI, LoadVal1); + if (E->getOp() == AtomicExpr::AO__atomic_nand_fetch) + Result = CGF.Builder.CreateNot(Result); + llvm::StoreInst *StoreDest = CGF.Builder.CreateStore(Result, Dest); + StoreDest->setAlignment(Align); +} + +// This function emits any expression (scalar, complex, or aggregate) +// into a temporary alloca. +static llvm::Value * +EmitValToTemp(CodeGenFunction &CGF, Expr *E) { + llvm::Value *DeclPtr = CGF.CreateMemTemp(E->getType(), ".atomictmp"); + CGF.EmitAnyExprToMem(E, DeclPtr, E->getType().getQualifiers(), + /*Init*/ true); + return DeclPtr; +} + +static void +AddDirectArgument(CodeGenFunction &CGF, CallArgList &Args, + bool UseOptimizedLibcall, llvm::Value *Val, QualType ValTy, + SourceLocation Loc, CharUnits SizeInChars) { + if (UseOptimizedLibcall) { + // Load value and pass it to the function directly. + unsigned Align = CGF.getContext().getTypeAlignInChars(ValTy).getQuantity(); + int64_t SizeInBits = CGF.getContext().toBits(SizeInChars); + ValTy = + CGF.getContext().getIntTypeForBitwidth(SizeInBits, /*Signed=*/false); + llvm::Type *IPtrTy = llvm::IntegerType::get(CGF.getLLVMContext(), + SizeInBits)->getPointerTo(); + Val = CGF.EmitLoadOfScalar(CGF.Builder.CreateBitCast(Val, IPtrTy), false, + Align, CGF.getContext().getPointerType(ValTy), + Loc); + // Coerce the value into an appropriately sized integer type. + Args.add(RValue::get(Val), ValTy); + } else { + // Non-optimized functions always take a reference. + Args.add(RValue::get(CGF.EmitCastToVoidPtr(Val)), + CGF.getContext().VoidPtrTy); + } +} + +RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E, llvm::Value *Dest) { + QualType AtomicTy = E->getPtr()->getType()->getPointeeType(); + QualType MemTy = AtomicTy; + if (const AtomicType *AT = AtomicTy->getAs<AtomicType>()) + MemTy = AT->getValueType(); + CharUnits sizeChars = getContext().getTypeSizeInChars(AtomicTy); + uint64_t Size = sizeChars.getQuantity(); + CharUnits alignChars = getContext().getTypeAlignInChars(AtomicTy); + unsigned Align = alignChars.getQuantity(); + unsigned MaxInlineWidthInBits = + getTarget().getMaxAtomicInlineWidth(); + bool UseLibcall = (Size != Align || + getContext().toBits(sizeChars) > MaxInlineWidthInBits); + + llvm::Value *IsWeak = nullptr, *OrderFail = nullptr, *Val1 = nullptr, + *Val2 = nullptr; + llvm::Value *Ptr = EmitScalarExpr(E->getPtr()); + + if (E->getOp() == AtomicExpr::AO__c11_atomic_init) { + assert(!Dest && "Init does not return a value"); + LValue lvalue = LValue::MakeAddr(Ptr, AtomicTy, alignChars, getContext()); + EmitAtomicInit(E->getVal1(), lvalue); + return RValue::get(nullptr); + } + + llvm::Value *Order = EmitScalarExpr(E->getOrder()); + + switch (E->getOp()) { + case AtomicExpr::AO__c11_atomic_init: + llvm_unreachable("Already handled!"); + + case AtomicExpr::AO__c11_atomic_load: + case AtomicExpr::AO__atomic_load_n: + break; + + case AtomicExpr::AO__atomic_load: + Dest = EmitScalarExpr(E->getVal1()); + break; + + case AtomicExpr::AO__atomic_store: + Val1 = EmitScalarExpr(E->getVal1()); + break; + + case AtomicExpr::AO__atomic_exchange: + Val1 = EmitScalarExpr(E->getVal1()); + Dest = EmitScalarExpr(E->getVal2()); + break; + + case AtomicExpr::AO__c11_atomic_compare_exchange_strong: + case AtomicExpr::AO__c11_atomic_compare_exchange_weak: + case AtomicExpr::AO__atomic_compare_exchange_n: + case AtomicExpr::AO__atomic_compare_exchange: + Val1 = EmitScalarExpr(E->getVal1()); + if (E->getOp() == AtomicExpr::AO__atomic_compare_exchange) + Val2 = EmitScalarExpr(E->getVal2()); + else + Val2 = EmitValToTemp(*this, E->getVal2()); + OrderFail = EmitScalarExpr(E->getOrderFail()); + if (E->getNumSubExprs() == 6) + IsWeak = EmitScalarExpr(E->getWeak()); + break; + + case AtomicExpr::AO__c11_atomic_fetch_add: + case AtomicExpr::AO__c11_atomic_fetch_sub: + if (MemTy->isPointerType()) { + // For pointer arithmetic, we're required to do a bit of math: + // adding 1 to an int* is not the same as adding 1 to a uintptr_t. + // ... but only for the C11 builtins. The GNU builtins expect the + // user to multiply by sizeof(T). + QualType Val1Ty = E->getVal1()->getType(); + llvm::Value *Val1Scalar = EmitScalarExpr(E->getVal1()); + CharUnits PointeeIncAmt = + getContext().getTypeSizeInChars(MemTy->getPointeeType()); + Val1Scalar = Builder.CreateMul(Val1Scalar, CGM.getSize(PointeeIncAmt)); + Val1 = CreateMemTemp(Val1Ty, ".atomictmp"); + EmitStoreOfScalar(Val1Scalar, MakeAddrLValue(Val1, Val1Ty)); + break; + } + // Fall through. + case AtomicExpr::AO__atomic_fetch_add: + case AtomicExpr::AO__atomic_fetch_sub: + case AtomicExpr::AO__atomic_add_fetch: + case AtomicExpr::AO__atomic_sub_fetch: + case AtomicExpr::AO__c11_atomic_store: + case AtomicExpr::AO__c11_atomic_exchange: + case AtomicExpr::AO__atomic_store_n: + case AtomicExpr::AO__atomic_exchange_n: + case AtomicExpr::AO__c11_atomic_fetch_and: + case AtomicExpr::AO__c11_atomic_fetch_or: + case AtomicExpr::AO__c11_atomic_fetch_xor: + case AtomicExpr::AO__atomic_fetch_and: + case AtomicExpr::AO__atomic_fetch_or: + case AtomicExpr::AO__atomic_fetch_xor: + case AtomicExpr::AO__atomic_fetch_nand: + case AtomicExpr::AO__atomic_and_fetch: + case AtomicExpr::AO__atomic_or_fetch: + case AtomicExpr::AO__atomic_xor_fetch: + case AtomicExpr::AO__atomic_nand_fetch: + Val1 = EmitValToTemp(*this, E->getVal1()); + break; + } + + QualType RValTy = E->getType().getUnqualifiedType(); + + auto GetDest = [&] { + if (!RValTy->isVoidType() && !Dest) { + Dest = CreateMemTemp(RValTy, ".atomicdst"); + } + return Dest; + }; + + // Use a library call. See: http://gcc.gnu.org/wiki/Atomic/GCCMM/LIbrary . + if (UseLibcall) { + bool UseOptimizedLibcall = false; + switch (E->getOp()) { + case AtomicExpr::AO__c11_atomic_fetch_add: + case AtomicExpr::AO__atomic_fetch_add: + case AtomicExpr::AO__c11_atomic_fetch_and: + case AtomicExpr::AO__atomic_fetch_and: + case AtomicExpr::AO__c11_atomic_fetch_or: + case AtomicExpr::AO__atomic_fetch_or: + case AtomicExpr::AO__c11_atomic_fetch_sub: + case AtomicExpr::AO__atomic_fetch_sub: + case AtomicExpr::AO__c11_atomic_fetch_xor: + case AtomicExpr::AO__atomic_fetch_xor: + // For these, only library calls for certain sizes exist. + UseOptimizedLibcall = true; + break; + default: + // Only use optimized library calls for sizes for which they exist. + if (Size == 1 || Size == 2 || Size == 4 || Size == 8) + UseOptimizedLibcall = true; + break; + } + + CallArgList Args; + if (!UseOptimizedLibcall) { + // For non-optimized library calls, the size is the first parameter + Args.add(RValue::get(llvm::ConstantInt::get(SizeTy, Size)), + getContext().getSizeType()); + } + // Atomic address is the first or second parameter + Args.add(RValue::get(EmitCastToVoidPtr(Ptr)), getContext().VoidPtrTy); + + std::string LibCallName; + QualType LoweredMemTy = + MemTy->isPointerType() ? getContext().getIntPtrType() : MemTy; + QualType RetTy; + bool HaveRetTy = false; + switch (E->getOp()) { + // There is only one libcall for compare an exchange, because there is no + // optimisation benefit possible from a libcall version of a weak compare + // and exchange. + // bool __atomic_compare_exchange(size_t size, void *mem, void *expected, + // void *desired, int success, int failure) + // bool __atomic_compare_exchange_N(T *mem, T *expected, T desired, + // int success, int failure) + case AtomicExpr::AO__c11_atomic_compare_exchange_weak: + case AtomicExpr::AO__c11_atomic_compare_exchange_strong: + case AtomicExpr::AO__atomic_compare_exchange: + case AtomicExpr::AO__atomic_compare_exchange_n: + LibCallName = "__atomic_compare_exchange"; + RetTy = getContext().BoolTy; + HaveRetTy = true; + Args.add(RValue::get(EmitCastToVoidPtr(Val1)), getContext().VoidPtrTy); + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val2, MemTy, + E->getExprLoc(), sizeChars); + Args.add(RValue::get(Order), getContext().IntTy); + Order = OrderFail; + break; + // void __atomic_exchange(size_t size, void *mem, void *val, void *return, + // int order) + // T __atomic_exchange_N(T *mem, T val, int order) + case AtomicExpr::AO__c11_atomic_exchange: + case AtomicExpr::AO__atomic_exchange_n: + case AtomicExpr::AO__atomic_exchange: + LibCallName = "__atomic_exchange"; + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy, + E->getExprLoc(), sizeChars); + break; + // void __atomic_store(size_t size, void *mem, void *val, int order) + // void __atomic_store_N(T *mem, T val, int order) + case AtomicExpr::AO__c11_atomic_store: + case AtomicExpr::AO__atomic_store: + case AtomicExpr::AO__atomic_store_n: + LibCallName = "__atomic_store"; + RetTy = getContext().VoidTy; + HaveRetTy = true; + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy, + E->getExprLoc(), sizeChars); + break; + // void __atomic_load(size_t size, void *mem, void *return, int order) + // T __atomic_load_N(T *mem, int order) + case AtomicExpr::AO__c11_atomic_load: + case AtomicExpr::AO__atomic_load: + case AtomicExpr::AO__atomic_load_n: + LibCallName = "__atomic_load"; + break; + // T __atomic_fetch_add_N(T *mem, T val, int order) + case AtomicExpr::AO__c11_atomic_fetch_add: + case AtomicExpr::AO__atomic_fetch_add: + LibCallName = "__atomic_fetch_add"; + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, LoweredMemTy, + E->getExprLoc(), sizeChars); + break; + // T __atomic_fetch_and_N(T *mem, T val, int order) + case AtomicExpr::AO__c11_atomic_fetch_and: + case AtomicExpr::AO__atomic_fetch_and: + LibCallName = "__atomic_fetch_and"; + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy, + E->getExprLoc(), sizeChars); + break; + // T __atomic_fetch_or_N(T *mem, T val, int order) + case AtomicExpr::AO__c11_atomic_fetch_or: + case AtomicExpr::AO__atomic_fetch_or: + LibCallName = "__atomic_fetch_or"; + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy, + E->getExprLoc(), sizeChars); + break; + // T __atomic_fetch_sub_N(T *mem, T val, int order) + case AtomicExpr::AO__c11_atomic_fetch_sub: + case AtomicExpr::AO__atomic_fetch_sub: + LibCallName = "__atomic_fetch_sub"; + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, LoweredMemTy, + E->getExprLoc(), sizeChars); + break; + // T __atomic_fetch_xor_N(T *mem, T val, int order) + case AtomicExpr::AO__c11_atomic_fetch_xor: + case AtomicExpr::AO__atomic_fetch_xor: + LibCallName = "__atomic_fetch_xor"; + AddDirectArgument(*this, Args, UseOptimizedLibcall, Val1, MemTy, + E->getExprLoc(), sizeChars); + break; + default: return EmitUnsupportedRValue(E, "atomic library call"); + } + + // Optimized functions have the size in their name. + if (UseOptimizedLibcall) + LibCallName += "_" + llvm::utostr(Size); + // By default, assume we return a value of the atomic type. + if (!HaveRetTy) { + if (UseOptimizedLibcall) { + // Value is returned directly. + // The function returns an appropriately sized integer type. + RetTy = getContext().getIntTypeForBitwidth( + getContext().toBits(sizeChars), /*Signed=*/false); + } else { + // Value is returned through parameter before the order. + RetTy = getContext().VoidTy; + Args.add(RValue::get(EmitCastToVoidPtr(Dest)), getContext().VoidPtrTy); + } + } + // order is always the last parameter + Args.add(RValue::get(Order), + getContext().IntTy); + + RValue Res = emitAtomicLibcall(*this, LibCallName, RetTy, Args); + // The value is returned directly from the libcall. + if (HaveRetTy && !RetTy->isVoidType()) + return Res; + // The value is returned via an explicit out param. + if (RetTy->isVoidType()) + return RValue::get(nullptr); + // The value is returned directly for optimized libcalls but the caller is + // expected an out-param. + if (UseOptimizedLibcall) { + llvm::Value *ResVal = Res.getScalarVal(); + llvm::StoreInst *StoreDest = Builder.CreateStore( + ResVal, + Builder.CreateBitCast(GetDest(), ResVal->getType()->getPointerTo())); + StoreDest->setAlignment(Align); + } + return convertTempToRValue(Dest, RValTy, E->getExprLoc()); + } + + bool IsStore = E->getOp() == AtomicExpr::AO__c11_atomic_store || + E->getOp() == AtomicExpr::AO__atomic_store || + E->getOp() == AtomicExpr::AO__atomic_store_n; + bool IsLoad = E->getOp() == AtomicExpr::AO__c11_atomic_load || + E->getOp() == AtomicExpr::AO__atomic_load || + E->getOp() == AtomicExpr::AO__atomic_load_n; + + llvm::Type *ITy = + llvm::IntegerType::get(getLLVMContext(), Size * 8); + llvm::Value *OrigDest = GetDest(); + Ptr = Builder.CreateBitCast( + Ptr, ITy->getPointerTo(Ptr->getType()->getPointerAddressSpace())); + if (Val1) Val1 = Builder.CreateBitCast(Val1, ITy->getPointerTo()); + if (Val2) Val2 = Builder.CreateBitCast(Val2, ITy->getPointerTo()); + if (Dest && !E->isCmpXChg()) + Dest = Builder.CreateBitCast(Dest, ITy->getPointerTo()); + + if (isa<llvm::ConstantInt>(Order)) { + int ord = cast<llvm::ConstantInt>(Order)->getZExtValue(); + switch (ord) { + case AtomicExpr::AO_ABI_memory_order_relaxed: + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::Monotonic); + break; + case AtomicExpr::AO_ABI_memory_order_consume: + case AtomicExpr::AO_ABI_memory_order_acquire: + if (IsStore) + break; // Avoid crashing on code with undefined behavior + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::Acquire); + break; + case AtomicExpr::AO_ABI_memory_order_release: + if (IsLoad) + break; // Avoid crashing on code with undefined behavior + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::Release); + break; + case AtomicExpr::AO_ABI_memory_order_acq_rel: + if (IsLoad || IsStore) + break; // Avoid crashing on code with undefined behavior + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::AcquireRelease); + break; + case AtomicExpr::AO_ABI_memory_order_seq_cst: + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::SequentiallyConsistent); + break; + default: // invalid order + // We should not ever get here normally, but it's hard to + // enforce that in general. + break; + } + if (RValTy->isVoidType()) + return RValue::get(nullptr); + return convertTempToRValue(OrigDest, RValTy, E->getExprLoc()); + } + + // Long case, when Order isn't obviously constant. + + // Create all the relevant BB's + llvm::BasicBlock *MonotonicBB = nullptr, *AcquireBB = nullptr, + *ReleaseBB = nullptr, *AcqRelBB = nullptr, + *SeqCstBB = nullptr; + MonotonicBB = createBasicBlock("monotonic", CurFn); + if (!IsStore) + AcquireBB = createBasicBlock("acquire", CurFn); + if (!IsLoad) + ReleaseBB = createBasicBlock("release", CurFn); + if (!IsLoad && !IsStore) + AcqRelBB = createBasicBlock("acqrel", CurFn); + SeqCstBB = createBasicBlock("seqcst", CurFn); + llvm::BasicBlock *ContBB = createBasicBlock("atomic.continue", CurFn); + + // Create the switch for the split + // MonotonicBB is arbitrarily chosen as the default case; in practice, this + // doesn't matter unless someone is crazy enough to use something that + // doesn't fold to a constant for the ordering. + Order = Builder.CreateIntCast(Order, Builder.getInt32Ty(), false); + llvm::SwitchInst *SI = Builder.CreateSwitch(Order, MonotonicBB); + + // Emit all the different atomics + Builder.SetInsertPoint(MonotonicBB); + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::Monotonic); + Builder.CreateBr(ContBB); + if (!IsStore) { + Builder.SetInsertPoint(AcquireBB); + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::Acquire); + Builder.CreateBr(ContBB); + SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_consume), + AcquireBB); + SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_acquire), + AcquireBB); + } + if (!IsLoad) { + Builder.SetInsertPoint(ReleaseBB); + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::Release); + Builder.CreateBr(ContBB); + SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_release), + ReleaseBB); + } + if (!IsLoad && !IsStore) { + Builder.SetInsertPoint(AcqRelBB); + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::AcquireRelease); + Builder.CreateBr(ContBB); + SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_acq_rel), + AcqRelBB); + } + Builder.SetInsertPoint(SeqCstBB); + EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, IsWeak, OrderFail, + Size, Align, llvm::SequentiallyConsistent); + Builder.CreateBr(ContBB); + SI->addCase(Builder.getInt32(AtomicExpr::AO_ABI_memory_order_seq_cst), + SeqCstBB); + + // Cleanup and return + Builder.SetInsertPoint(ContBB); + if (RValTy->isVoidType()) + return RValue::get(nullptr); + return convertTempToRValue(OrigDest, RValTy, E->getExprLoc()); +} + +llvm::Value *AtomicInfo::emitCastToAtomicIntPointer(llvm::Value *addr) const { + unsigned addrspace = + cast<llvm::PointerType>(addr->getType())->getAddressSpace(); + llvm::IntegerType *ty = + llvm::IntegerType::get(CGF.getLLVMContext(), AtomicSizeInBits); + return CGF.Builder.CreateBitCast(addr, ty->getPointerTo(addrspace)); +} + +RValue AtomicInfo::convertTempToRValue(llvm::Value *addr, + AggValueSlot resultSlot, + SourceLocation loc, bool AsValue) const { + if (LVal.isSimple()) { + if (EvaluationKind == TEK_Aggregate) + return resultSlot.asRValue(); + + // Drill into the padding structure if we have one. + if (hasPadding()) + addr = CGF.Builder.CreateStructGEP(nullptr, addr, 0); + + // Otherwise, just convert the temporary to an r-value using the + // normal conversion routine. + return CGF.convertTempToRValue(addr, getValueType(), loc); + } + if (!AsValue) + // Get RValue from temp memory as atomic for non-simple lvalues + return RValue::get( + CGF.Builder.CreateAlignedLoad(addr, AtomicAlign.getQuantity())); + if (LVal.isBitField()) + return CGF.EmitLoadOfBitfieldLValue(LValue::MakeBitfield( + addr, LVal.getBitFieldInfo(), LVal.getType(), LVal.getAlignment())); + if (LVal.isVectorElt()) + return CGF.EmitLoadOfLValue(LValue::MakeVectorElt(addr, LVal.getVectorIdx(), + LVal.getType(), + LVal.getAlignment()), + loc); + assert(LVal.isExtVectorElt()); + return CGF.EmitLoadOfExtVectorElementLValue(LValue::MakeExtVectorElt( + addr, LVal.getExtVectorElts(), LVal.getType(), LVal.getAlignment())); +} + +RValue AtomicInfo::ConvertIntToValueOrAtomic(llvm::Value *IntVal, + AggValueSlot ResultSlot, + SourceLocation Loc, + bool AsValue) const { + // Try not to in some easy cases. + assert(IntVal->getType()->isIntegerTy() && "Expected integer value"); + if (getEvaluationKind() == TEK_Scalar && + (((!LVal.isBitField() || + LVal.getBitFieldInfo().Size == ValueSizeInBits) && + !hasPadding()) || + !AsValue)) { + auto *ValTy = AsValue + ? CGF.ConvertTypeForMem(ValueTy) + : getAtomicAddress()->getType()->getPointerElementType(); + if (ValTy->isIntegerTy()) { + assert(IntVal->getType() == ValTy && "Different integer types."); + return RValue::get(CGF.EmitFromMemory(IntVal, ValueTy)); + } else if (ValTy->isPointerTy()) + return RValue::get(CGF.Builder.CreateIntToPtr(IntVal, ValTy)); + else if (llvm::CastInst::isBitCastable(IntVal->getType(), ValTy)) + return RValue::get(CGF.Builder.CreateBitCast(IntVal, ValTy)); + } + + // Create a temporary. This needs to be big enough to hold the + // atomic integer. + llvm::Value *Temp; + bool TempIsVolatile = false; + CharUnits TempAlignment; + if (AsValue && getEvaluationKind() == TEK_Aggregate) { + assert(!ResultSlot.isIgnored()); + Temp = ResultSlot.getAddr(); + TempAlignment = getValueAlignment(); + TempIsVolatile = ResultSlot.isVolatile(); + } else { + Temp = CreateTempAlloca(); + TempAlignment = getAtomicAlignment(); + } + + // Slam the integer into the temporary. + llvm::Value *CastTemp = emitCastToAtomicIntPointer(Temp); + CGF.Builder.CreateAlignedStore(IntVal, CastTemp, TempAlignment.getQuantity()) + ->setVolatile(TempIsVolatile); + + return convertTempToRValue(Temp, ResultSlot, Loc, AsValue); +} + +void AtomicInfo::EmitAtomicLoadLibcall(llvm::Value *AddForLoaded, + llvm::AtomicOrdering AO, bool) { + // void __atomic_load(size_t size, void *mem, void *return, int order); + CallArgList Args; + Args.add(RValue::get(getAtomicSizeValue()), CGF.getContext().getSizeType()); + Args.add(RValue::get(CGF.EmitCastToVoidPtr(getAtomicAddress())), + CGF.getContext().VoidPtrTy); + Args.add(RValue::get(CGF.EmitCastToVoidPtr(AddForLoaded)), + CGF.getContext().VoidPtrTy); + Args.add(RValue::get( + llvm::ConstantInt::get(CGF.IntTy, translateAtomicOrdering(AO))), + CGF.getContext().IntTy); + emitAtomicLibcall(CGF, "__atomic_load", CGF.getContext().VoidTy, Args); +} + +llvm::Value *AtomicInfo::EmitAtomicLoadOp(llvm::AtomicOrdering AO, + bool IsVolatile) { + // Okay, we're doing this natively. + llvm::Value *Addr = emitCastToAtomicIntPointer(getAtomicAddress()); + llvm::LoadInst *Load = CGF.Builder.CreateLoad(Addr, "atomic-load"); + Load->setAtomic(AO); + + // Other decoration. + Load->setAlignment(getAtomicAlignment().getQuantity()); + if (IsVolatile) + Load->setVolatile(true); + if (LVal.getTBAAInfo()) + CGF.CGM.DecorateInstruction(Load, LVal.getTBAAInfo()); + return Load; +} + +/// An LValue is a candidate for having its loads and stores be made atomic if +/// we are operating under /volatile:ms *and* the LValue itself is volatile and +/// performing such an operation can be performed without a libcall. +bool CodeGenFunction::LValueIsSuitableForInlineAtomic(LValue LV) { + AtomicInfo AI(*this, LV); + bool IsVolatile = LV.isVolatile() || hasVolatileMember(LV.getType()); + // An atomic is inline if we don't need to use a libcall. + bool AtomicIsInline = !AI.shouldUseLibcall(); + return CGM.getCodeGenOpts().MSVolatile && IsVolatile && AtomicIsInline; +} + +/// An type is a candidate for having its loads and stores be made atomic if +/// we are operating under /volatile:ms *and* we know the access is volatile and +/// performing such an operation can be performed without a libcall. +bool CodeGenFunction::typeIsSuitableForInlineAtomic(QualType Ty, + bool IsVolatile) const { + // An atomic is inline if we don't need to use a libcall (e.g. it is builtin). + bool AtomicIsInline = getContext().getTargetInfo().hasBuiltinAtomic( + getContext().getTypeSize(Ty), getContext().getTypeAlign(Ty)); + return CGM.getCodeGenOpts().MSVolatile && IsVolatile && AtomicIsInline; +} + +RValue CodeGenFunction::EmitAtomicLoad(LValue LV, SourceLocation SL, + AggValueSlot Slot) { + llvm::AtomicOrdering AO; + bool IsVolatile = LV.isVolatileQualified(); + if (LV.getType()->isAtomicType()) { + AO = llvm::SequentiallyConsistent; + } else { + AO = llvm::Acquire; + IsVolatile = true; + } + return EmitAtomicLoad(LV, SL, AO, IsVolatile, Slot); +} + +RValue AtomicInfo::EmitAtomicLoad(AggValueSlot ResultSlot, SourceLocation Loc, + bool AsValue, llvm::AtomicOrdering AO, + bool IsVolatile) { + // Check whether we should use a library call. + if (shouldUseLibcall()) { + llvm::Value *TempAddr; + if (LVal.isSimple() && !ResultSlot.isIgnored()) { + assert(getEvaluationKind() == TEK_Aggregate); + TempAddr = ResultSlot.getAddr(); + } else + TempAddr = CreateTempAlloca(); + + EmitAtomicLoadLibcall(TempAddr, AO, IsVolatile); + + // Okay, turn that back into the original value or whole atomic (for + // non-simple lvalues) type. + return convertTempToRValue(TempAddr, ResultSlot, Loc, AsValue); + } + + // Okay, we're doing this natively. + auto *Load = EmitAtomicLoadOp(AO, IsVolatile); + + // If we're ignoring an aggregate return, don't do anything. + if (getEvaluationKind() == TEK_Aggregate && ResultSlot.isIgnored()) + return RValue::getAggregate(nullptr, false); + + // Okay, turn that back into the original value or atomic (for non-simple + // lvalues) type. + return ConvertIntToValueOrAtomic(Load, ResultSlot, Loc, AsValue); +} + +/// Emit a load from an l-value of atomic type. Note that the r-value +/// we produce is an r-value of the atomic *value* type. +RValue CodeGenFunction::EmitAtomicLoad(LValue src, SourceLocation loc, + llvm::AtomicOrdering AO, bool IsVolatile, + AggValueSlot resultSlot) { + AtomicInfo Atomics(*this, src); + return Atomics.EmitAtomicLoad(resultSlot, loc, /*AsValue=*/true, AO, + IsVolatile); +} + +/// Copy an r-value into memory as part of storing to an atomic type. +/// This needs to create a bit-pattern suitable for atomic operations. +void AtomicInfo::emitCopyIntoMemory(RValue rvalue) const { + assert(LVal.isSimple()); + // If we have an r-value, the rvalue should be of the atomic type, + // which means that the caller is responsible for having zeroed + // any padding. Just do an aggregate copy of that type. + if (rvalue.isAggregate()) { + CGF.EmitAggregateCopy(getAtomicAddress(), + rvalue.getAggregateAddr(), + getAtomicType(), + (rvalue.isVolatileQualified() + || LVal.isVolatileQualified()), + LVal.getAlignment()); + return; + } + + // Okay, otherwise we're copying stuff. + + // Zero out the buffer if necessary. + emitMemSetZeroIfNecessary(); + + // Drill past the padding if present. + LValue TempLVal = projectValue(); + + // Okay, store the rvalue in. + if (rvalue.isScalar()) { + CGF.EmitStoreOfScalar(rvalue.getScalarVal(), TempLVal, /*init*/ true); + } else { + CGF.EmitStoreOfComplex(rvalue.getComplexVal(), TempLVal, /*init*/ true); + } +} + + +/// Materialize an r-value into memory for the purposes of storing it +/// to an atomic type. +llvm::Value *AtomicInfo::materializeRValue(RValue rvalue) const { + // Aggregate r-values are already in memory, and EmitAtomicStore + // requires them to be values of the atomic type. + if (rvalue.isAggregate()) + return rvalue.getAggregateAddr(); + + // Otherwise, make a temporary and materialize into it. + LValue TempLV = CGF.MakeAddrLValue(CreateTempAlloca(), getAtomicType(), + getAtomicAlignment()); + AtomicInfo Atomics(CGF, TempLV); + Atomics.emitCopyIntoMemory(rvalue); + return TempLV.getAddress(); +} + +llvm::Value *AtomicInfo::convertRValueToInt(RValue RVal) const { + // If we've got a scalar value of the right size, try to avoid going + // through memory. + if (RVal.isScalar() && (!hasPadding() || !LVal.isSimple())) { + llvm::Value *Value = RVal.getScalarVal(); + if (isa<llvm::IntegerType>(Value->getType())) + return CGF.EmitToMemory(Value, ValueTy); + else { + llvm::IntegerType *InputIntTy = llvm::IntegerType::get( + CGF.getLLVMContext(), + LVal.isSimple() ? getValueSizeInBits() : getAtomicSizeInBits()); + if (isa<llvm::PointerType>(Value->getType())) + return CGF.Builder.CreatePtrToInt(Value, InputIntTy); + else if (llvm::BitCastInst::isBitCastable(Value->getType(), InputIntTy)) + return CGF.Builder.CreateBitCast(Value, InputIntTy); + } + } + // Otherwise, we need to go through memory. + // Put the r-value in memory. + llvm::Value *Addr = materializeRValue(RVal); + + // Cast the temporary to the atomic int type and pull a value out. + Addr = emitCastToAtomicIntPointer(Addr); + return CGF.Builder.CreateAlignedLoad(Addr, + getAtomicAlignment().getQuantity()); +} + +std::pair<llvm::Value *, llvm::Value *> AtomicInfo::EmitAtomicCompareExchangeOp( + llvm::Value *ExpectedVal, llvm::Value *DesiredVal, + llvm::AtomicOrdering Success, llvm::AtomicOrdering Failure, bool IsWeak) { + // Do the atomic store. + auto *Addr = emitCastToAtomicIntPointer(getAtomicAddress()); + auto *Inst = CGF.Builder.CreateAtomicCmpXchg(Addr, ExpectedVal, DesiredVal, + Success, Failure); + // Other decoration. + Inst->setVolatile(LVal.isVolatileQualified()); + Inst->setWeak(IsWeak); + + // Okay, turn that back into the original value type. + auto *PreviousVal = CGF.Builder.CreateExtractValue(Inst, /*Idxs=*/0); + auto *SuccessFailureVal = CGF.Builder.CreateExtractValue(Inst, /*Idxs=*/1); + return std::make_pair(PreviousVal, SuccessFailureVal); +} + +llvm::Value * +AtomicInfo::EmitAtomicCompareExchangeLibcall(llvm::Value *ExpectedAddr, + llvm::Value *DesiredAddr, + llvm::AtomicOrdering Success, + llvm::AtomicOrdering Failure) { + // bool __atomic_compare_exchange(size_t size, void *obj, void *expected, + // void *desired, int success, int failure); + CallArgList Args; + Args.add(RValue::get(getAtomicSizeValue()), CGF.getContext().getSizeType()); + Args.add(RValue::get(CGF.EmitCastToVoidPtr(getAtomicAddress())), + CGF.getContext().VoidPtrTy); + Args.add(RValue::get(CGF.EmitCastToVoidPtr(ExpectedAddr)), + CGF.getContext().VoidPtrTy); + Args.add(RValue::get(CGF.EmitCastToVoidPtr(DesiredAddr)), + CGF.getContext().VoidPtrTy); + Args.add(RValue::get(llvm::ConstantInt::get( + CGF.IntTy, translateAtomicOrdering(Success))), + CGF.getContext().IntTy); + Args.add(RValue::get(llvm::ConstantInt::get( + CGF.IntTy, translateAtomicOrdering(Failure))), + CGF.getContext().IntTy); + auto SuccessFailureRVal = emitAtomicLibcall(CGF, "__atomic_compare_exchange", + CGF.getContext().BoolTy, Args); + + return SuccessFailureRVal.getScalarVal(); +} + +std::pair<RValue, llvm::Value *> AtomicInfo::EmitAtomicCompareExchange( + RValue Expected, RValue Desired, llvm::AtomicOrdering Success, + llvm::AtomicOrdering Failure, bool IsWeak) { + if (Failure >= Success) + // Don't assert on undefined behavior. + Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(Success); + + // Check whether we should use a library call. + if (shouldUseLibcall()) { + // Produce a source address. + auto *ExpectedAddr = materializeRValue(Expected); + auto *DesiredAddr = materializeRValue(Desired); + auto *Res = EmitAtomicCompareExchangeLibcall(ExpectedAddr, DesiredAddr, + Success, Failure); + return std::make_pair( + convertTempToRValue(ExpectedAddr, AggValueSlot::ignored(), + SourceLocation(), /*AsValue=*/false), + Res); + } + + // If we've got a scalar value of the right size, try to avoid going + // through memory. + auto *ExpectedVal = convertRValueToInt(Expected); + auto *DesiredVal = convertRValueToInt(Desired); + auto Res = EmitAtomicCompareExchangeOp(ExpectedVal, DesiredVal, Success, + Failure, IsWeak); + return std::make_pair( + ConvertIntToValueOrAtomic(Res.first, AggValueSlot::ignored(), + SourceLocation(), /*AsValue=*/false), + Res.second); +} + +static void +EmitAtomicUpdateValue(CodeGenFunction &CGF, AtomicInfo &Atomics, RValue OldRVal, + const llvm::function_ref<RValue(RValue)> &UpdateOp, + llvm::Value *DesiredAddr) { + llvm::Value *Ptr = nullptr; + LValue UpdateLVal; + RValue UpRVal; + LValue AtomicLVal = Atomics.getAtomicLValue(); + LValue DesiredLVal; + if (AtomicLVal.isSimple()) { + UpRVal = OldRVal; + DesiredLVal = + LValue::MakeAddr(DesiredAddr, AtomicLVal.getType(), + AtomicLVal.getAlignment(), CGF.CGM.getContext()); + } else { + // Build new lvalue for temp address + Ptr = Atomics.materializeRValue(OldRVal); + if (AtomicLVal.isBitField()) { + UpdateLVal = + LValue::MakeBitfield(Ptr, AtomicLVal.getBitFieldInfo(), + AtomicLVal.getType(), AtomicLVal.getAlignment()); + DesiredLVal = + LValue::MakeBitfield(DesiredAddr, AtomicLVal.getBitFieldInfo(), + AtomicLVal.getType(), AtomicLVal.getAlignment()); + } else if (AtomicLVal.isVectorElt()) { + UpdateLVal = LValue::MakeVectorElt(Ptr, AtomicLVal.getVectorIdx(), + AtomicLVal.getType(), + AtomicLVal.getAlignment()); + DesiredLVal = LValue::MakeVectorElt( + DesiredAddr, AtomicLVal.getVectorIdx(), AtomicLVal.getType(), + AtomicLVal.getAlignment()); + } else { + assert(AtomicLVal.isExtVectorElt()); + UpdateLVal = LValue::MakeExtVectorElt(Ptr, AtomicLVal.getExtVectorElts(), + AtomicLVal.getType(), + AtomicLVal.getAlignment()); + DesiredLVal = LValue::MakeExtVectorElt( + DesiredAddr, AtomicLVal.getExtVectorElts(), AtomicLVal.getType(), + AtomicLVal.getAlignment()); + } + UpdateLVal.setTBAAInfo(AtomicLVal.getTBAAInfo()); + DesiredLVal.setTBAAInfo(AtomicLVal.getTBAAInfo()); + UpRVal = CGF.EmitLoadOfLValue(UpdateLVal, SourceLocation()); + } + // Store new value in the corresponding memory area + RValue NewRVal = UpdateOp(UpRVal); + if (NewRVal.isScalar()) { + CGF.EmitStoreThroughLValue(NewRVal, DesiredLVal); + } else { + assert(NewRVal.isComplex()); + CGF.EmitStoreOfComplex(NewRVal.getComplexVal(), DesiredLVal, + /*isInit=*/false); + } +} + +void AtomicInfo::EmitAtomicUpdateLibcall( + llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, + bool IsVolatile) { + auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); + + llvm::Value *ExpectedAddr = CreateTempAlloca(); + + EmitAtomicLoadLibcall(ExpectedAddr, AO, IsVolatile); + auto *ContBB = CGF.createBasicBlock("atomic_cont"); + auto *ExitBB = CGF.createBasicBlock("atomic_exit"); + CGF.EmitBlock(ContBB); + auto *DesiredAddr = CreateTempAlloca(); + if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || + requiresMemSetZero( + getAtomicAddress()->getType()->getPointerElementType())) { + auto *OldVal = CGF.Builder.CreateAlignedLoad( + ExpectedAddr, getAtomicAlignment().getQuantity()); + CGF.Builder.CreateAlignedStore(OldVal, DesiredAddr, + getAtomicAlignment().getQuantity()); + } + auto OldRVal = convertTempToRValue(ExpectedAddr, AggValueSlot::ignored(), + SourceLocation(), /*AsValue=*/false); + EmitAtomicUpdateValue(CGF, *this, OldRVal, UpdateOp, DesiredAddr); + auto *Res = + EmitAtomicCompareExchangeLibcall(ExpectedAddr, DesiredAddr, AO, Failure); + CGF.Builder.CreateCondBr(Res, ExitBB, ContBB); + CGF.EmitBlock(ExitBB, /*IsFinished=*/true); +} + +void AtomicInfo::EmitAtomicUpdateOp( + llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, + bool IsVolatile) { + auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); + + // Do the atomic load. + auto *OldVal = EmitAtomicLoadOp(AO, IsVolatile); + // For non-simple lvalues perform compare-and-swap procedure. + auto *ContBB = CGF.createBasicBlock("atomic_cont"); + auto *ExitBB = CGF.createBasicBlock("atomic_exit"); + auto *CurBB = CGF.Builder.GetInsertBlock(); + CGF.EmitBlock(ContBB); + llvm::PHINode *PHI = CGF.Builder.CreatePHI(OldVal->getType(), + /*NumReservedValues=*/2); + PHI->addIncoming(OldVal, CurBB); + auto *NewAtomicAddr = CreateTempAlloca(); + auto *NewAtomicIntAddr = emitCastToAtomicIntPointer(NewAtomicAddr); + if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || + requiresMemSetZero( + getAtomicAddress()->getType()->getPointerElementType())) { + CGF.Builder.CreateAlignedStore(PHI, NewAtomicIntAddr, + getAtomicAlignment().getQuantity()); + } + auto OldRVal = ConvertIntToValueOrAtomic(PHI, AggValueSlot::ignored(), + SourceLocation(), /*AsValue=*/false); + EmitAtomicUpdateValue(CGF, *this, OldRVal, UpdateOp, NewAtomicAddr); + auto *DesiredVal = CGF.Builder.CreateAlignedLoad( + NewAtomicIntAddr, getAtomicAlignment().getQuantity()); + // Try to write new value using cmpxchg operation + auto Res = EmitAtomicCompareExchangeOp(PHI, DesiredVal, AO, Failure); + PHI->addIncoming(Res.first, CGF.Builder.GetInsertBlock()); + CGF.Builder.CreateCondBr(Res.second, ExitBB, ContBB); + CGF.EmitBlock(ExitBB, /*IsFinished=*/true); +} + +static void EmitAtomicUpdateValue(CodeGenFunction &CGF, AtomicInfo &Atomics, + RValue UpdateRVal, llvm::Value *DesiredAddr) { + LValue AtomicLVal = Atomics.getAtomicLValue(); + LValue DesiredLVal; + // Build new lvalue for temp address + if (AtomicLVal.isBitField()) { + DesiredLVal = + LValue::MakeBitfield(DesiredAddr, AtomicLVal.getBitFieldInfo(), + AtomicLVal.getType(), AtomicLVal.getAlignment()); + } else if (AtomicLVal.isVectorElt()) { + DesiredLVal = + LValue::MakeVectorElt(DesiredAddr, AtomicLVal.getVectorIdx(), + AtomicLVal.getType(), AtomicLVal.getAlignment()); + } else { + assert(AtomicLVal.isExtVectorElt()); + DesiredLVal = LValue::MakeExtVectorElt( + DesiredAddr, AtomicLVal.getExtVectorElts(), AtomicLVal.getType(), + AtomicLVal.getAlignment()); + } + DesiredLVal.setTBAAInfo(AtomicLVal.getTBAAInfo()); + // Store new value in the corresponding memory area + assert(UpdateRVal.isScalar()); + CGF.EmitStoreThroughLValue(UpdateRVal, DesiredLVal); +} + +void AtomicInfo::EmitAtomicUpdateLibcall(llvm::AtomicOrdering AO, + RValue UpdateRVal, bool IsVolatile) { + auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); + + llvm::Value *ExpectedAddr = CreateTempAlloca(); + + EmitAtomicLoadLibcall(ExpectedAddr, AO, IsVolatile); + auto *ContBB = CGF.createBasicBlock("atomic_cont"); + auto *ExitBB = CGF.createBasicBlock("atomic_exit"); + CGF.EmitBlock(ContBB); + auto *DesiredAddr = CreateTempAlloca(); + if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || + requiresMemSetZero( + getAtomicAddress()->getType()->getPointerElementType())) { + auto *OldVal = CGF.Builder.CreateAlignedLoad( + ExpectedAddr, getAtomicAlignment().getQuantity()); + CGF.Builder.CreateAlignedStore(OldVal, DesiredAddr, + getAtomicAlignment().getQuantity()); + } + EmitAtomicUpdateValue(CGF, *this, UpdateRVal, DesiredAddr); + auto *Res = + EmitAtomicCompareExchangeLibcall(ExpectedAddr, DesiredAddr, AO, Failure); + CGF.Builder.CreateCondBr(Res, ExitBB, ContBB); + CGF.EmitBlock(ExitBB, /*IsFinished=*/true); +} + +void AtomicInfo::EmitAtomicUpdateOp(llvm::AtomicOrdering AO, RValue UpdateRVal, + bool IsVolatile) { + auto Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO); + + // Do the atomic load. + auto *OldVal = EmitAtomicLoadOp(AO, IsVolatile); + // For non-simple lvalues perform compare-and-swap procedure. + auto *ContBB = CGF.createBasicBlock("atomic_cont"); + auto *ExitBB = CGF.createBasicBlock("atomic_exit"); + auto *CurBB = CGF.Builder.GetInsertBlock(); + CGF.EmitBlock(ContBB); + llvm::PHINode *PHI = CGF.Builder.CreatePHI(OldVal->getType(), + /*NumReservedValues=*/2); + PHI->addIncoming(OldVal, CurBB); + auto *NewAtomicAddr = CreateTempAlloca(); + auto *NewAtomicIntAddr = emitCastToAtomicIntPointer(NewAtomicAddr); + if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) || + requiresMemSetZero( + getAtomicAddress()->getType()->getPointerElementType())) { + CGF.Builder.CreateAlignedStore(PHI, NewAtomicIntAddr, + getAtomicAlignment().getQuantity()); + } + EmitAtomicUpdateValue(CGF, *this, UpdateRVal, NewAtomicAddr); + auto *DesiredVal = CGF.Builder.CreateAlignedLoad( + NewAtomicIntAddr, getAtomicAlignment().getQuantity()); + // Try to write new value using cmpxchg operation + auto Res = EmitAtomicCompareExchangeOp(PHI, DesiredVal, AO, Failure); + PHI->addIncoming(Res.first, CGF.Builder.GetInsertBlock()); + CGF.Builder.CreateCondBr(Res.second, ExitBB, ContBB); + CGF.EmitBlock(ExitBB, /*IsFinished=*/true); +} + +void AtomicInfo::EmitAtomicUpdate( + llvm::AtomicOrdering AO, const llvm::function_ref<RValue(RValue)> &UpdateOp, + bool IsVolatile) { + if (shouldUseLibcall()) { + EmitAtomicUpdateLibcall(AO, UpdateOp, IsVolatile); + } else { + EmitAtomicUpdateOp(AO, UpdateOp, IsVolatile); + } +} + +void AtomicInfo::EmitAtomicUpdate(llvm::AtomicOrdering AO, RValue UpdateRVal, + bool IsVolatile) { + if (shouldUseLibcall()) { + EmitAtomicUpdateLibcall(AO, UpdateRVal, IsVolatile); + } else { + EmitAtomicUpdateOp(AO, UpdateRVal, IsVolatile); + } +} + +void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue lvalue, + bool isInit) { + bool IsVolatile = lvalue.isVolatileQualified(); + llvm::AtomicOrdering AO; + if (lvalue.getType()->isAtomicType()) { + AO = llvm::SequentiallyConsistent; + } else { + AO = llvm::Release; + IsVolatile = true; + } + return EmitAtomicStore(rvalue, lvalue, AO, IsVolatile, isInit); +} + +/// Emit a store to an l-value of atomic type. +/// +/// Note that the r-value is expected to be an r-value *of the atomic +/// type*; this means that for aggregate r-values, it should include +/// storage for any padding that was necessary. +void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, + llvm::AtomicOrdering AO, bool IsVolatile, + bool isInit) { + // If this is an aggregate r-value, it should agree in type except + // maybe for address-space qualification. + assert(!rvalue.isAggregate() || + rvalue.getAggregateAddr()->getType()->getPointerElementType() + == dest.getAddress()->getType()->getPointerElementType()); + + AtomicInfo atomics(*this, dest); + LValue LVal = atomics.getAtomicLValue(); + + // If this is an initialization, just put the value there normally. + if (LVal.isSimple()) { + if (isInit) { + atomics.emitCopyIntoMemory(rvalue); + return; + } + + // Check whether we should use a library call. + if (atomics.shouldUseLibcall()) { + // Produce a source address. + llvm::Value *srcAddr = atomics.materializeRValue(rvalue); + + // void __atomic_store(size_t size, void *mem, void *val, int order) + CallArgList args; + args.add(RValue::get(atomics.getAtomicSizeValue()), + getContext().getSizeType()); + args.add(RValue::get(EmitCastToVoidPtr(atomics.getAtomicAddress())), + getContext().VoidPtrTy); + args.add(RValue::get(EmitCastToVoidPtr(srcAddr)), getContext().VoidPtrTy); + args.add(RValue::get(llvm::ConstantInt::get( + IntTy, AtomicInfo::translateAtomicOrdering(AO))), + getContext().IntTy); + emitAtomicLibcall(*this, "__atomic_store", getContext().VoidTy, args); + return; + } + + // Okay, we're doing this natively. + llvm::Value *intValue = atomics.convertRValueToInt(rvalue); + + // Do the atomic store. + llvm::Value *addr = + atomics.emitCastToAtomicIntPointer(atomics.getAtomicAddress()); + intValue = Builder.CreateIntCast( + intValue, addr->getType()->getPointerElementType(), /*isSigned=*/false); + llvm::StoreInst *store = Builder.CreateStore(intValue, addr); + + // Initializations don't need to be atomic. + if (!isInit) + store->setAtomic(AO); + + // Other decoration. + store->setAlignment(dest.getAlignment().getQuantity()); + if (IsVolatile) + store->setVolatile(true); + if (dest.getTBAAInfo()) + CGM.DecorateInstruction(store, dest.getTBAAInfo()); + return; + } + + // Emit simple atomic update operation. + atomics.EmitAtomicUpdate(AO, rvalue, IsVolatile); +} + +/// Emit a compare-and-exchange op for atomic type. +/// +std::pair<RValue, llvm::Value *> CodeGenFunction::EmitAtomicCompareExchange( + LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc, + llvm::AtomicOrdering Success, llvm::AtomicOrdering Failure, bool IsWeak, + AggValueSlot Slot) { + // If this is an aggregate r-value, it should agree in type except + // maybe for address-space qualification. + assert(!Expected.isAggregate() || + Expected.getAggregateAddr()->getType()->getPointerElementType() == + Obj.getAddress()->getType()->getPointerElementType()); + assert(!Desired.isAggregate() || + Desired.getAggregateAddr()->getType()->getPointerElementType() == + Obj.getAddress()->getType()->getPointerElementType()); + AtomicInfo Atomics(*this, Obj); + + return Atomics.EmitAtomicCompareExchange(Expected, Desired, Success, Failure, + IsWeak); +} + +void CodeGenFunction::EmitAtomicUpdate( + LValue LVal, llvm::AtomicOrdering AO, + const llvm::function_ref<RValue(RValue)> &UpdateOp, bool IsVolatile) { + AtomicInfo Atomics(*this, LVal); + Atomics.EmitAtomicUpdate(AO, UpdateOp, IsVolatile); +} + +void CodeGenFunction::EmitAtomicInit(Expr *init, LValue dest) { + AtomicInfo atomics(*this, dest); + + switch (atomics.getEvaluationKind()) { + case TEK_Scalar: { + llvm::Value *value = EmitScalarExpr(init); + atomics.emitCopyIntoMemory(RValue::get(value)); + return; + } + + case TEK_Complex: { + ComplexPairTy value = EmitComplexExpr(init); + atomics.emitCopyIntoMemory(RValue::getComplex(value)); + return; + } + + case TEK_Aggregate: { + // Fix up the destination if the initializer isn't an expression + // of atomic type. + bool Zeroed = false; + if (!init->getType()->isAtomicType()) { + Zeroed = atomics.emitMemSetZeroIfNecessary(); + dest = atomics.projectValue(); + } + + // Evaluate the expression directly into the destination. + AggValueSlot slot = AggValueSlot::forLValue(dest, + AggValueSlot::IsNotDestructed, + AggValueSlot::DoesNotNeedGCBarriers, + AggValueSlot::IsNotAliased, + Zeroed ? AggValueSlot::IsZeroed : + AggValueSlot::IsNotZeroed); + + EmitAggExpr(init, slot); + return; + } + } + llvm_unreachable("bad evaluation kind"); +} |
