| //===--- 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); |
| |
| /// 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. |
| std::pair<RValue, llvm::Value *> EmitAtomicCompareExchangeLibcall( |
| RValue Expected, RValue DesiredAddr, |
| llvm::AtomicOrdering Success = llvm::SequentiallyConsistent, |
| llvm::AtomicOrdering Failure = llvm::SequentiallyConsistent); |
| /// \brief Emits atomic compare-and-exchange op as LLVM instruction. |
| std::pair<RValue, llvm::Value *> EmitAtomicCompareExchangeOp( |
| RValue Expected, RValue Desired, |
| llvm::AtomicOrdering Success = llvm::SequentiallyConsistent, |
| llvm::AtomicOrdering Failure = llvm::SequentiallyConsistent, |
| bool IsWeak = false); |
| }; |
| } |
| |
| 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<RValue, llvm::Value *> AtomicInfo::EmitAtomicCompareExchangeOp( |
| RValue Expected, RValue Desired, llvm::AtomicOrdering Success, |
| llvm::AtomicOrdering Failure, bool IsWeak) { |
| // Do the atomic store. |
| auto *ExpectedVal = convertRValueToInt(Expected); |
| auto *DesiredVal = convertRValueToInt(Desired); |
| 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( |
| ConvertIntToValueOrAtomic(PreviousVal, AggValueSlot::ignored(), |
| SourceLocation(), /*AsValue=*/false), |
| SuccessFailureVal); |
| } |
| |
| std::pair<RValue, llvm::Value *> |
| AtomicInfo::EmitAtomicCompareExchangeLibcall(RValue Expected, RValue Desired, |
| llvm::AtomicOrdering Success, |
| llvm::AtomicOrdering Failure) { |
| // bool __atomic_compare_exchange(size_t size, void *obj, void *expected, |
| // void *desired, int success, int failure); |
| auto *ExpectedAddr = materializeRValue(Expected); |
| auto *DesiredAddr = materializeRValue(Desired); |
| 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 std::make_pair( |
| convertTempToRValue(ExpectedAddr, AggValueSlot::ignored(), |
| SourceLocation(), /*AsValue=*/false), |
| 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. |
| return EmitAtomicCompareExchangeLibcall(Expected, Desired, Success, |
| Failure); |
| } |
| |
| // If we've got a scalar value of the right size, try to avoid going |
| // through memory. |
| return EmitAtomicCompareExchangeOp(Expected, Desired, Success, Failure, |
| IsWeak); |
| } |
| |
| 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; |
| } |
| |
| // Atomic load of prev value. |
| RValue OldRVal = |
| atomics.EmitAtomicLoad(AggValueSlot::ignored(), SourceLocation(), |
| /*AsValue=*/false, AO, IsVolatile); |
| // For non-simple lvalues perform compare-and-swap procedure. |
| auto *ContBB = createBasicBlock("atomic_cont"); |
| auto *ExitBB = createBasicBlock("atomic_exit"); |
| auto *CurBB = Builder.GetInsertBlock(); |
| EmitBlock(ContBB); |
| llvm::PHINode *PHI = Builder.CreatePHI(OldRVal.getScalarVal()->getType(), |
| /*NumReservedValues=*/2); |
| PHI->addIncoming(OldRVal.getScalarVal(), CurBB); |
| RValue OriginalRValue = RValue::get(PHI); |
| // Build new lvalue for temp address |
| auto *Ptr = atomics.materializeRValue(OriginalRValue); |
| // Build new lvalue for temp address |
| LValue UpdateLVal; |
| if (LVal.isBitField()) |
| UpdateLVal = LValue::MakeBitfield(Ptr, LVal.getBitFieldInfo(), |
| LVal.getType(), LVal.getAlignment()); |
| else if (LVal.isVectorElt()) |
| UpdateLVal = LValue::MakeVectorElt(Ptr, LVal.getVectorIdx(), LVal.getType(), |
| LVal.getAlignment()); |
| else { |
| assert(LVal.isExtVectorElt()); |
| UpdateLVal = LValue::MakeExtVectorElt(Ptr, LVal.getExtVectorElts(), |
| LVal.getType(), LVal.getAlignment()); |
| } |
| UpdateLVal.setTBAAInfo(LVal.getTBAAInfo()); |
| // Store new value in the corresponding memory area |
| EmitStoreThroughLValue(rvalue, UpdateLVal); |
| // Load new value |
| RValue NewRValue = RValue::get(EmitLoadOfScalar( |
| Ptr, LVal.isVolatile(), atomics.getAtomicAlignment().getQuantity(), |
| atomics.getAtomicType(), SourceLocation())); |
| // Try to write new value using cmpxchg operation |
| auto Pair = atomics.EmitAtomicCompareExchange(OriginalRValue, NewRValue, AO); |
| PHI->addIncoming(Pair.first.getScalarVal(), ContBB); |
| Builder.CreateCondBr(Pair.second, ExitBB, ContBB); |
| EmitBlock(ExitBB, /*IsFinished=*/true); |
| } |
| |
| /// 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 std::function<RValue(RValue)> &UpdateOp, bool IsVolatile) { |
| AtomicInfo Atomics(*this, LVal); |
| LValue AtomicLVal = Atomics.getAtomicLValue(); |
| |
| // Atomic load of prev value. |
| RValue OldRVal = |
| Atomics.EmitAtomicLoad(AggValueSlot::ignored(), SourceLocation(), |
| /*AsValue=*/false, AO, IsVolatile); |
| bool IsScalar = OldRVal.isScalar(); |
| auto *OldVal = |
| IsScalar ? OldRVal.getScalarVal() : Atomics.convertRValueToInt(OldRVal); |
| // For non-simple lvalues perform compare-and-swap procedure. |
| auto *ContBB = createBasicBlock("atomic_cont"); |
| auto *ExitBB = createBasicBlock("atomic_exit"); |
| auto *CurBB = Builder.GetInsertBlock(); |
| EmitBlock(ContBB); |
| llvm::PHINode *PHI = Builder.CreatePHI(OldVal->getType(), |
| /*NumReservedValues=*/2); |
| PHI->addIncoming(OldVal, CurBB); |
| RValue OriginalRValue = |
| IsScalar ? RValue::get(PHI) : Atomics.ConvertIntToValueOrAtomic( |
| PHI, AggValueSlot::ignored(), |
| SourceLocation(), /*AsValue=*/false); |
| // Build new lvalue for temp address |
| LValue UpdateLVal; |
| llvm::Value *Ptr = nullptr; |
| RValue UpRVal; |
| if (AtomicLVal.isSimple()) { |
| UpRVal = OriginalRValue; |
| } else { |
| // Build new lvalue for temp address |
| Ptr = Atomics.materializeRValue(OriginalRValue); |
| if (AtomicLVal.isBitField()) |
| UpdateLVal = |
| LValue::MakeBitfield(Ptr, AtomicLVal.getBitFieldInfo(), |
| AtomicLVal.getType(), AtomicLVal.getAlignment()); |
| else if (AtomicLVal.isVectorElt()) |
| UpdateLVal = LValue::MakeVectorElt(Ptr, AtomicLVal.getVectorIdx(), |
| AtomicLVal.getType(), |
| AtomicLVal.getAlignment()); |
| else { |
| assert(AtomicLVal.isExtVectorElt()); |
| UpdateLVal = LValue::MakeExtVectorElt(Ptr, AtomicLVal.getExtVectorElts(), |
| AtomicLVal.getType(), |
| AtomicLVal.getAlignment()); |
| } |
| UpdateLVal.setTBAAInfo(LVal.getTBAAInfo()); |
| UpRVal = EmitLoadOfLValue(UpdateLVal, SourceLocation()); |
| } |
| // Store new value in the corresponding memory area |
| RValue NewRVal = UpdateOp(UpRVal); |
| if (!AtomicLVal.isSimple()) { |
| EmitStoreThroughLValue(NewRVal, UpdateLVal); |
| // Load new value |
| NewRVal = RValue::get( |
| EmitLoadOfScalar(Ptr, AtomicLVal.isVolatile(), |
| Atomics.getAtomicAlignment().getQuantity(), |
| Atomics.getAtomicType(), SourceLocation())); |
| } |
| // Try to write new value using cmpxchg operation |
| auto Pair = Atomics.EmitAtomicCompareExchange(OriginalRValue, NewRVal, AO); |
| OldVal = IsScalar ? Pair.first.getScalarVal() |
| : Atomics.convertRValueToInt(Pair.first); |
| PHI->addIncoming(OldVal, ContBB); |
| Builder.CreateCondBr(Pair.second, ExitBB, ContBB); |
| EmitBlock(ExitBB, /*IsFinished=*/true); |
| } |
| |
| 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"); |
| } |