//===--- 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()) 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()->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 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 &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 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 &UpdateOp, bool IsVolatile); /// \brief Emit atomic update as LLVM instructions. void EmitAtomicUpdateOp(llvm::AtomicOrdering AO, const llvm::function_ref &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(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(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()) 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(Order)) { int ord = cast(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(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(Value->getType())) return CGF.EmitToMemory(Value, ValueTy); else { llvm::IntegerType *InputIntTy = llvm::IntegerType::get( CGF.getLLVMContext(), LVal.isSimple() ? getValueSizeInBits() : getAtomicSizeInBits()); if (isa(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 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 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 &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 &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 &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 &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 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 &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"); }