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Diffstat (limited to 'js/src/jit/shared/Lowering-shared.h')
| -rw-r--r-- | js/src/jit/shared/Lowering-shared.h | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/js/src/jit/shared/Lowering-shared.h b/js/src/jit/shared/Lowering-shared.h new file mode 100644 index 000000000..e73df780e --- /dev/null +++ b/js/src/jit/shared/Lowering-shared.h @@ -0,0 +1,296 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- + * vim: set ts=8 sts=4 et sw=4 tw=99: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef jit_shared_Lowering_shared_h +#define jit_shared_Lowering_shared_h + +// This file declares the structures that are used for attaching LIR to a +// MIRGraph. + +#include "jit/LIR.h" +#include "jit/MIRGenerator.h" + +namespace js { +namespace jit { + +class MIRGenerator; +class MIRGraph; +class MDefinition; +class MInstruction; +class LOsiPoint; + +class LIRGeneratorShared : public MDefinitionVisitor +{ + protected: + MIRGenerator* gen; + MIRGraph& graph; + LIRGraph& lirGraph_; + LBlock* current; + MResumePoint* lastResumePoint_; + LRecoverInfo* cachedRecoverInfo_; + LOsiPoint* osiPoint_; + + public: + LIRGeneratorShared(MIRGenerator* gen, MIRGraph& graph, LIRGraph& lirGraph) + : gen(gen), + graph(graph), + lirGraph_(lirGraph), + lastResumePoint_(nullptr), + cachedRecoverInfo_(nullptr), + osiPoint_(nullptr) + { } + + MIRGenerator* mir() { + return gen; + } + + protected: + + static void ReorderCommutative(MDefinition** lhsp, MDefinition** rhsp, MInstruction* ins); + static bool ShouldReorderCommutative(MDefinition* lhs, MDefinition* rhs, MInstruction* ins); + + // A backend can decide that an instruction should be emitted at its uses, + // rather than at its definition. To communicate this, set the + // instruction's virtual register set to 0. When using the instruction, + // its virtual register is temporarily reassigned. To know to clear it + // after constructing the use information, the worklist bit is temporarily + // unset. + // + // The backend can use the worklist bit to determine whether or not a + // definition should be created. + inline void emitAtUses(MInstruction* mir); + + // The lowest-level calls to use, those that do not wrap another call to + // use(), must prefix grabbing virtual register IDs by these calls. + inline void ensureDefined(MDefinition* mir); + + // These all create a use of a virtual register, with an optional + // allocation policy. + // + // Some of these use functions have atStart variants. + // - non-atStart variants will tell the register allocator that the input + // allocation must be different from any Temp or Definition also needed for + // this LInstruction. + // - atStart variants relax that restriction and allow the input to be in + // the same register as any Temp or output Definition used by the + // LInstruction. Note that it doesn't *imply* this will actually happen, + // but gives a hint to the register allocator that it can do it. + // + // TL;DR: Use non-atStart variants only if you need the input value after + // writing to any temp or definitions, during code generation of this + // LInstruction. Otherwise, use atStart variants, which will lower register + // pressure. + inline LUse use(MDefinition* mir, LUse policy); + inline LUse use(MDefinition* mir); + inline LUse useAtStart(MDefinition* mir); + inline LUse useRegister(MDefinition* mir); + inline LUse useRegisterAtStart(MDefinition* mir); + inline LUse useFixed(MDefinition* mir, Register reg); + inline LUse useFixed(MDefinition* mir, FloatRegister reg); + inline LUse useFixed(MDefinition* mir, AnyRegister reg); + inline LUse useFixedAtStart(MDefinition* mir, Register reg); + inline LUse useFixedAtStart(MDefinition* mir, AnyRegister reg); + inline LAllocation useOrConstant(MDefinition* mir); + inline LAllocation useOrConstantAtStart(MDefinition* mir); + // "Any" is architecture dependent, and will include registers and stack + // slots on X86, and only registers on ARM. + inline LAllocation useAny(MDefinition* mir); + inline LAllocation useAnyOrConstant(MDefinition* mir); + // "Storable" is architecture dependend, and will include registers and + // constants on X86 and only registers on ARM. This is a generic "things + // we can expect to write into memory in 1 instruction". + inline LAllocation useStorable(MDefinition* mir); + inline LAllocation useStorableAtStart(MDefinition* mir); + inline LAllocation useKeepalive(MDefinition* mir); + inline LAllocation useKeepaliveOrConstant(MDefinition* mir); + inline LAllocation useRegisterOrConstant(MDefinition* mir); + inline LAllocation useRegisterOrConstantAtStart(MDefinition* mir); + inline LAllocation useRegisterOrZeroAtStart(MDefinition* mir); + inline LAllocation useRegisterOrNonDoubleConstant(MDefinition* mir); + + inline LUse useRegisterForTypedLoad(MDefinition* mir, MIRType type); + +#ifdef JS_NUNBOX32 + inline LUse useType(MDefinition* mir, LUse::Policy policy); + inline LUse usePayload(MDefinition* mir, LUse::Policy policy); + inline LUse usePayloadAtStart(MDefinition* mir, LUse::Policy policy); + inline LUse usePayloadInRegisterAtStart(MDefinition* mir); + + // Adds a box input to an instruction, setting operand |n| to the type and + // |n+1| to the payload. Does not modify the operands, instead expecting a + // policy to already be set. + inline void fillBoxUses(LInstruction* lir, size_t n, MDefinition* mir); +#endif + + // These create temporary register requests. + inline LDefinition temp(LDefinition::Type type = LDefinition::GENERAL, + LDefinition::Policy policy = LDefinition::REGISTER); + inline LInt64Definition tempInt64(LDefinition::Policy policy = LDefinition::REGISTER); + inline LDefinition tempFloat32(); + inline LDefinition tempDouble(); + inline LDefinition tempCopy(MDefinition* input, uint32_t reusedInput); + + // Note that the fixed register has a GENERAL type. + inline LDefinition tempFixed(Register reg); + + template <size_t Ops, size_t Temps> + inline void defineFixed(LInstructionHelper<1, Ops, Temps>* lir, MDefinition* mir, + const LAllocation& output); + + template <size_t Ops, size_t Temps> + inline void defineBox(LInstructionHelper<BOX_PIECES, Ops, Temps>* lir, MDefinition* mir, + LDefinition::Policy policy = LDefinition::REGISTER); + + template <size_t Ops, size_t Temps> + inline void defineInt64(LInstructionHelper<INT64_PIECES, Ops, Temps>* lir, MDefinition* mir, + LDefinition::Policy policy = LDefinition::REGISTER); + + template <size_t Ops, size_t Temps> + inline void defineInt64Fixed(LInstructionHelper<INT64_PIECES, Ops, Temps>* lir, MDefinition* mir, + const LInt64Allocation& output); + + template <size_t Ops, size_t Temps> + inline void defineSinCos(LInstructionHelper<2, Ops, Temps> *lir, MDefinition *mir, + LDefinition::Policy policy = LDefinition::REGISTER); + + inline void defineSharedStubReturn(LInstruction* lir, MDefinition* mir); + inline void defineReturn(LInstruction* lir, MDefinition* mir); + + template <size_t X> + inline void define(details::LInstructionFixedDefsTempsHelper<1, X>* lir, MDefinition* mir, + LDefinition::Policy policy = LDefinition::REGISTER); + template <size_t X> + inline void define(details::LInstructionFixedDefsTempsHelper<1, X>* lir, MDefinition* mir, + const LDefinition& def); + + template <size_t Ops, size_t Temps> + inline void defineReuseInput(LInstructionHelper<1, Ops, Temps>* lir, MDefinition* mir, + uint32_t operand); + + template <size_t Ops, size_t Temps> + inline void defineInt64ReuseInput(LInstructionHelper<INT64_PIECES, Ops, Temps>* lir, + MDefinition* mir, uint32_t operand); + + // Returns a box allocation for a Value-typed instruction. + inline LBoxAllocation useBox(MDefinition* mir, LUse::Policy policy = LUse::REGISTER, + bool useAtStart = false); + + // Returns a box allocation. The use is either typed, a Value, or + // a constant (if useConstant is true). + inline LBoxAllocation useBoxOrTypedOrConstant(MDefinition* mir, bool useConstant); + + // Returns an int64 allocation for an Int64-typed instruction. + inline LInt64Allocation useInt64(MDefinition* mir, LUse::Policy policy, bool useAtStart); + inline LInt64Allocation useInt64(MDefinition* mir, bool useAtStart = false); + inline LInt64Allocation useInt64AtStart(MDefinition* mir); + inline LInt64Allocation useInt64OrConstant(MDefinition* mir, bool useAtStart = false); + inline LInt64Allocation useInt64Register(MDefinition* mir, bool useAtStart = false); + inline LInt64Allocation useInt64RegisterOrConstant(MDefinition* mir, bool useAtStart = false); + inline LInt64Allocation useInt64Fixed(MDefinition* mir, Register64 regs, bool useAtStart = false); + + LInt64Allocation useInt64RegisterAtStart(MDefinition* mir) { + return useInt64Register(mir, /* useAtStart = */ true); + } + LInt64Allocation useInt64RegisterOrConstantAtStart(MDefinition* mir) { + return useInt64RegisterOrConstant(mir, /* useAtStart = */ true); + } + LInt64Allocation useInt64OrConstantAtStart(MDefinition* mir) { + return useInt64OrConstant(mir, /* useAtStart = */ true); + } + + // Rather than defining a new virtual register, sets |ins| to have the same + // virtual register as |as|. + inline void redefine(MDefinition* ins, MDefinition* as); + + // Redefine a sin/cos call to sincos. + inline void redefine(MDefinition* def, MDefinition* as, MMathFunction::Function func); + + TempAllocator& alloc() const { + return graph.alloc(); + } + + uint32_t getVirtualRegister() { + uint32_t vreg = lirGraph_.getVirtualRegister(); + + // If we run out of virtual registers, mark code generation as having + // failed and return a dummy vreg. Include a + 1 here for NUNBOX32 + // platforms that expect Value vregs to be adjacent. + if (vreg + 1 >= MAX_VIRTUAL_REGISTERS) { + gen->abort("max virtual registers"); + return 1; + } + return vreg; + } + + template <typename T> void annotate(T* ins); + template <typename T> void add(T* ins, MInstruction* mir = nullptr); + + void lowerTypedPhiInput(MPhi* phi, uint32_t inputPosition, LBlock* block, size_t lirIndex); + void defineTypedPhi(MPhi* phi, size_t lirIndex); + + LOsiPoint* popOsiPoint() { + LOsiPoint* tmp = osiPoint_; + osiPoint_ = nullptr; + return tmp; + } + + LRecoverInfo* getRecoverInfo(MResumePoint* rp); + LSnapshot* buildSnapshot(LInstruction* ins, MResumePoint* rp, BailoutKind kind); + bool assignPostSnapshot(MInstruction* mir, LInstruction* ins); + + // Marks this instruction as fallible, meaning that before it performs + // effects (if any), it may check pre-conditions and bailout if they do not + // hold. This function informs the register allocator that it will need to + // capture appropriate state. + void assignSnapshot(LInstruction* ins, BailoutKind kind); + + // Marks this instruction as needing to call into either the VM or GC. This + // function may build a snapshot that captures the result of its own + // instruction, and as such, should generally be called after define*(). + void assignSafepoint(LInstruction* ins, MInstruction* mir, + BailoutKind kind = Bailout_DuringVMCall); + + public: + void lowerConstantDouble(double d, MInstruction* mir) { + define(new(alloc()) LDouble(wasm::RawF64(d)), mir); + } + void lowerConstantFloat32(float f, MInstruction* mir) { + define(new(alloc()) LFloat32(wasm::RawF32(f)), mir); + } + + void visitConstant(MConstant* ins) override; + + // Whether to generate typed reads for element accesses with hole checks. + static bool allowTypedElementHoleCheck() { + return false; + } + + // Whether to generate typed array accesses on statically known objects. + static bool allowStaticTypedArrayAccesses() { + return false; + } + + // Provide NYI default implementations of the SIMD visitor functions. + // Many targets don't implement SIMD at all, and we don't want to duplicate + // these stubs in the specific sub-classes. + // Some SIMD visitors are implemented in LIRGenerator in Lowering.cpp. These + // shared implementations are not included here. + void visitSimdInsertElement(MSimdInsertElement*) override { MOZ_CRASH("NYI"); } + void visitSimdExtractElement(MSimdExtractElement*) override { MOZ_CRASH("NYI"); } + void visitSimdBinaryArith(MSimdBinaryArith*) override { MOZ_CRASH("NYI"); } + void visitSimdSelect(MSimdSelect*) override { MOZ_CRASH("NYI"); } + void visitSimdSplat(MSimdSplat*) override { MOZ_CRASH("NYI"); } + void visitSimdValueX4(MSimdValueX4*) override { MOZ_CRASH("NYI"); } + void visitSimdBinarySaturating(MSimdBinarySaturating*) override { MOZ_CRASH("NYI"); } + void visitSimdSwizzle(MSimdSwizzle*) override { MOZ_CRASH("NYI"); } + void visitSimdShuffle(MSimdShuffle*) override { MOZ_CRASH("NYI"); } + void visitSimdGeneralShuffle(MSimdGeneralShuffle*) override { MOZ_CRASH("NYI"); } +}; + +} // namespace jit +} // namespace js + +#endif /* jit_shared_Lowering_shared_h */ |