diff options
Diffstat (limited to 'js/src/jit/LIR.cpp')
-rw-r--r-- | js/src/jit/LIR.cpp | 732 |
1 files changed, 732 insertions, 0 deletions
diff --git a/js/src/jit/LIR.cpp b/js/src/jit/LIR.cpp new file mode 100644 index 0000000000..a083f347ef --- /dev/null +++ b/js/src/jit/LIR.cpp @@ -0,0 +1,732 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * 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/. */ + +#include "jit/LIR.h" + +#include "mozilla/ScopeExit.h" + +#include <type_traits> + +#include "jit/JitSpewer.h" +#include "jit/MIR.h" +#include "jit/MIRGenerator.h" +#include "js/Printf.h" +#include "util/Unicode.h" + +using namespace js; +using namespace js::jit; + +const char* const js::jit::LIROpNames[] = { +#define OPNAME(op, ...) #op, + LIR_OPCODE_LIST(OPNAME) +#undef OPNAME +}; + +LIRGraph::LIRGraph(MIRGraph* mir) + : blocks_(), + constantPool_(mir->alloc()), + constantPoolMap_(mir->alloc()), + safepoints_(mir->alloc()), + nonCallSafepoints_(mir->alloc()), + numVirtualRegisters_(0), + numInstructions_(1), // First id is 1. + localSlotsSize_(0), + argumentSlotCount_(0), + mir_(*mir) {} + +bool LIRGraph::addConstantToPool(const Value& v, uint32_t* index) { + ConstantPoolMap::AddPtr p = constantPoolMap_.lookupForAdd(v); + if (p) { + *index = p->value(); + return true; + } + *index = constantPool_.length(); + return constantPool_.append(v) && constantPoolMap_.add(p, v, *index); +} + +bool LIRGraph::noteNeedsSafepoint(LInstruction* ins) { + // Instructions with safepoints must be in linear order. + MOZ_ASSERT_IF(!safepoints_.empty(), safepoints_.back()->id() < ins->id()); + if (!ins->isCall() && !nonCallSafepoints_.append(ins)) { + return false; + } + return safepoints_.append(ins); +} + +#ifdef JS_JITSPEW +void LIRGraph::dump(GenericPrinter& out) { + for (size_t i = 0; i < numBlocks(); i++) { + getBlock(i)->dump(out); + out.printf("\n"); + } +} + +void LIRGraph::dump() { + Fprinter out(stderr); + dump(out); + out.finish(); +} +#endif + +LBlock::LBlock(MBasicBlock* from) + : block_(from), phis_(), entryMoveGroup_(nullptr), exitMoveGroup_(nullptr) { + from->assignLir(this); +} + +bool LBlock::init(TempAllocator& alloc) { + // Count the number of LPhis we'll need. + size_t numLPhis = 0; + for (MPhiIterator i(block_->phisBegin()), e(block_->phisEnd()); i != e; ++i) { + MPhi* phi = *i; + switch (phi->type()) { + case MIRType::Value: + numLPhis += BOX_PIECES; + break; + case MIRType::Int64: + numLPhis += INT64_PIECES; + break; + default: + numLPhis += 1; + break; + } + } + + // Allocate space for the LPhis. + if (!phis_.init(alloc, numLPhis)) { + return false; + } + + // For each MIR phi, set up LIR phis as appropriate. We'll fill in their + // operands on each incoming edge, and set their definitions at the start of + // their defining block. + size_t phiIndex = 0; + size_t numPreds = block_->numPredecessors(); + for (MPhiIterator i(block_->phisBegin()), e(block_->phisEnd()); i != e; ++i) { + MPhi* phi = *i; + MOZ_ASSERT(phi->numOperands() == numPreds); + + int numPhis; + switch (phi->type()) { + case MIRType::Value: + numPhis = BOX_PIECES; + break; + case MIRType::Int64: + numPhis = INT64_PIECES; + break; + default: + numPhis = 1; + break; + } + for (int i = 0; i < numPhis; i++) { + LAllocation* inputs = alloc.allocateArray<LAllocation>(numPreds); + if (!inputs) { + return false; + } + + void* addr = &phis_[phiIndex++]; + LPhi* lphi = new (addr) LPhi(phi, inputs); + lphi->setBlock(this); + } + } + return true; +} + +const LInstruction* LBlock::firstInstructionWithId() const { + for (LInstructionIterator i(instructions_.begin()); i != instructions_.end(); + ++i) { + if (i->id()) { + return *i; + } + } + return 0; +} + +LMoveGroup* LBlock::getEntryMoveGroup(TempAllocator& alloc) { + if (entryMoveGroup_) { + return entryMoveGroup_; + } + entryMoveGroup_ = LMoveGroup::New(alloc); + insertBefore(*begin(), entryMoveGroup_); + return entryMoveGroup_; +} + +LMoveGroup* LBlock::getExitMoveGroup(TempAllocator& alloc) { + if (exitMoveGroup_) { + return exitMoveGroup_; + } + exitMoveGroup_ = LMoveGroup::New(alloc); + insertBefore(*rbegin(), exitMoveGroup_); + return exitMoveGroup_; +} + +#ifdef JS_JITSPEW +void LBlock::dump(GenericPrinter& out) { + out.printf("block%u:\n", mir()->id()); + for (size_t i = 0; i < numPhis(); ++i) { + getPhi(i)->dump(out); + out.printf("\n"); + } + for (LInstructionIterator iter = begin(); iter != end(); iter++) { + iter->dump(out); + if (iter->safepoint()) { + out.printf(" SAFEPOINT(0x%p) ", iter->safepoint()); + } + out.printf("\n"); + } +} + +void LBlock::dump() { + Fprinter out(stderr); + dump(out); + out.finish(); +} +#endif + +static size_t TotalOperandCount(LRecoverInfo* recoverInfo) { + size_t accum = 0; + for (LRecoverInfo::OperandIter it(recoverInfo); !it; ++it) { + if (!it->isRecoveredOnBailout()) { + accum++; + } + } + return accum; +} + +LRecoverInfo::LRecoverInfo(TempAllocator& alloc) + : instructions_(alloc), recoverOffset_(INVALID_RECOVER_OFFSET) {} + +LRecoverInfo* LRecoverInfo::New(MIRGenerator* gen, MResumePoint* mir) { + LRecoverInfo* recoverInfo = new (gen->alloc()) LRecoverInfo(gen->alloc()); + if (!recoverInfo || !recoverInfo->init(mir)) { + return nullptr; + } + + JitSpew(JitSpew_IonSnapshots, "Generating LIR recover info %p from MIR (%p)", + (void*)recoverInfo, (void*)mir); + + return recoverInfo; +} + +// de-virtualise MResumePoint::getOperand calls. +template <typename Node> +bool LRecoverInfo::appendOperands(Node* ins) { + for (size_t i = 0, end = ins->numOperands(); i < end; i++) { + MDefinition* def = ins->getOperand(i); + + // As there is no cycle in the data-flow (without MPhi), checking for + // isInWorkList implies that the definition is already in the + // instruction vector, and not processed by a caller of the current + // function. + if (def->isRecoveredOnBailout() && !def->isInWorklist()) { + if (!appendDefinition(def)) { + return false; + } + } + } + + return true; +} + +bool LRecoverInfo::appendDefinition(MDefinition* def) { + MOZ_ASSERT(def->isRecoveredOnBailout()); + def->setInWorklist(); + auto clearWorklistFlagOnFailure = + mozilla::MakeScopeExit([&] { def->setNotInWorklist(); }); + + if (!appendOperands(def)) { + return false; + } + + if (!instructions_.append(def)) { + return false; + } + + clearWorklistFlagOnFailure.release(); + return true; +} + +bool LRecoverInfo::appendResumePoint(MResumePoint* rp) { + // Stores should be recovered first. + for (auto iter(rp->storesBegin()), end(rp->storesEnd()); iter != end; + ++iter) { + if (!appendDefinition(iter->operand)) { + return false; + } + } + + if (rp->caller() && !appendResumePoint(rp->caller())) { + return false; + } + + if (!appendOperands(rp)) { + return false; + } + + return instructions_.append(rp); +} + +bool LRecoverInfo::init(MResumePoint* rp) { + // Before exiting this function, remove temporary flags from all definitions + // added in the vector. + auto clearWorklistFlags = mozilla::MakeScopeExit([&] { + for (MNode** it = begin(); it != end(); it++) { + if (!(*it)->isDefinition()) { + continue; + } + (*it)->toDefinition()->setNotInWorklist(); + } + }); + + // Sort operations in the order in which we need to restore the stack. This + // implies that outer frames, as well as operations needed to recover the + // current frame, are located before the current frame. The inner-most + // resume point should be the last element in the list. + if (!appendResumePoint(rp)) { + return false; + } + + MOZ_ASSERT(mir() == rp); + return true; +} + +LSnapshot::LSnapshot(LRecoverInfo* recoverInfo, BailoutKind kind) + : slots_(nullptr), + recoverInfo_(recoverInfo), + snapshotOffset_(INVALID_SNAPSHOT_OFFSET), + numSlots_(TotalOperandCount(recoverInfo) * BOX_PIECES), + bailoutKind_(kind) {} + +bool LSnapshot::init(MIRGenerator* gen) { + slots_ = gen->allocate<LAllocation>(numSlots_); + return !!slots_; +} + +LSnapshot* LSnapshot::New(MIRGenerator* gen, LRecoverInfo* recover, + BailoutKind kind) { + LSnapshot* snapshot = new (gen->alloc()) LSnapshot(recover, kind); + if (!snapshot || !snapshot->init(gen)) { + return nullptr; + } + + JitSpew(JitSpew_IonSnapshots, "Generating LIR snapshot %p from recover (%p)", + (void*)snapshot, (void*)recover); + + return snapshot; +} + +void LSnapshot::rewriteRecoveredInput(LUse input) { + // Mark any operands to this snapshot with the same value as input as being + // equal to the instruction's result. + for (size_t i = 0; i < numEntries(); i++) { + if (getEntry(i)->isUse() && + getEntry(i)->toUse()->virtualRegister() == input.virtualRegister()) { + setEntry(i, LUse(input.virtualRegister(), LUse::RECOVERED_INPUT)); + } + } +} + +#ifdef JS_JITSPEW +void LNode::printName(GenericPrinter& out, Opcode op) { + static const char* const names[] = { +# define LIROP(x) #x, + LIR_OPCODE_LIST(LIROP) +# undef LIROP + }; + const char* name = names[uint32_t(op)]; + size_t len = strlen(name); + for (size_t i = 0; i < len; i++) { + out.printf("%c", unicode::ToLowerCase(name[i])); + } +} + +void LNode::printName(GenericPrinter& out) { printName(out, op()); } +#endif + +bool LAllocation::aliases(const LAllocation& other) const { + if (isFloatReg() && other.isFloatReg()) { + return toFloatReg()->reg().aliases(other.toFloatReg()->reg()); + } + return *this == other; +} + +#ifdef JS_JITSPEW +static const char* DefTypeName(LDefinition::Type type) { + switch (type) { + case LDefinition::GENERAL: + return "g"; + case LDefinition::INT32: + return "i"; + case LDefinition::OBJECT: + return "o"; + case LDefinition::SLOTS: + return "s"; + case LDefinition::FLOAT32: + return "f"; + case LDefinition::DOUBLE: + return "d"; + case LDefinition::SIMD128: + return "simd128"; + case LDefinition::STACKRESULTS: + return "stackresults"; +# ifdef JS_NUNBOX32 + case LDefinition::TYPE: + return "t"; + case LDefinition::PAYLOAD: + return "p"; +# else + case LDefinition::BOX: + return "x"; +# endif + } + MOZ_CRASH("Invalid type"); +} + +UniqueChars LDefinition::toString() const { + AutoEnterOOMUnsafeRegion oomUnsafe; + + UniqueChars buf; + if (isBogusTemp()) { + buf = JS_smprintf("bogus"); + } else { + buf = JS_smprintf("v%u<%s>", virtualRegister(), DefTypeName(type())); + if (buf) { + if (policy() == LDefinition::FIXED) { + buf = JS_sprintf_append(std::move(buf), ":%s", + output()->toString().get()); + } else if (policy() == LDefinition::MUST_REUSE_INPUT) { + buf = JS_sprintf_append(std::move(buf), ":tied(%u)", getReusedInput()); + } + } + } + + if (!buf) { + oomUnsafe.crash("LDefinition::toString()"); + } + + return buf; +} + +static UniqueChars PrintUse(const LUse* use) { + switch (use->policy()) { + case LUse::REGISTER: + return JS_smprintf("v%u:R", use->virtualRegister()); + case LUse::FIXED: + return JS_smprintf("v%u:F:%s", use->virtualRegister(), + AnyRegister::FromCode(use->registerCode()).name()); + case LUse::ANY: + return JS_smprintf("v%u:A", use->virtualRegister()); + case LUse::KEEPALIVE: + return JS_smprintf("v%u:KA", use->virtualRegister()); + case LUse::STACK: + return JS_smprintf("v%u:S", use->virtualRegister()); + case LUse::RECOVERED_INPUT: + return JS_smprintf("v%u:RI", use->virtualRegister()); + default: + MOZ_CRASH("invalid use policy"); + } +} + +UniqueChars LAllocation::toString() const { + AutoEnterOOMUnsafeRegion oomUnsafe; + + UniqueChars buf; + if (isBogus()) { + buf = JS_smprintf("bogus"); + } else { + switch (kind()) { + case LAllocation::CONSTANT_VALUE: + case LAllocation::CONSTANT_INDEX: + buf = JS_smprintf("c"); + break; + case LAllocation::GPR: + buf = JS_smprintf("%s", toGeneralReg()->reg().name()); + break; + case LAllocation::FPU: + buf = JS_smprintf("%s", toFloatReg()->reg().name()); + break; + case LAllocation::STACK_SLOT: + buf = JS_smprintf("stack:%u", toStackSlot()->slot()); + break; + case LAllocation::ARGUMENT_SLOT: + buf = JS_smprintf("arg:%u", toArgument()->index()); + break; + case LAllocation::STACK_AREA: + buf = JS_smprintf("stackarea:%u+%u", toStackArea()->base(), + toStackArea()->size()); + break; + case LAllocation::USE: + buf = PrintUse(toUse()); + break; + default: + MOZ_CRASH("what?"); + } + } + + if (!buf) { + oomUnsafe.crash("LAllocation::toString()"); + } + + return buf; +} + +void LAllocation::dump() const { fprintf(stderr, "%s\n", toString().get()); } + +void LDefinition::dump() const { fprintf(stderr, "%s\n", toString().get()); } + +template <typename T> +static void PrintOperands(GenericPrinter& out, T* node) { + size_t numOperands = node->numOperands(); + + for (size_t i = 0; i < numOperands; i++) { + out.printf(" (%s)", node->getOperand(i)->toString().get()); + if (i != numOperands - 1) { + out.printf(","); + } + } +} + +void LNode::printOperands(GenericPrinter& out) { + if (isMoveGroup()) { + toMoveGroup()->printOperands(out); + return; + } + + if (isPhi()) { + PrintOperands(out, toPhi()); + } else { + PrintOperands(out, toInstruction()); + } +} +#endif + +void LInstruction::assignSnapshot(LSnapshot* snapshot) { + MOZ_ASSERT(!snapshot_); + snapshot_ = snapshot; + +#ifdef JS_JITSPEW + if (JitSpewEnabled(JitSpew_IonSnapshots)) { + JitSpewHeader(JitSpew_IonSnapshots); + Fprinter& out = JitSpewPrinter(); + out.printf("Assigning snapshot %p to instruction %p (", (void*)snapshot, + (void*)this); + printName(out); + out.printf(")\n"); + } +#endif +} + +#ifdef JS_JITSPEW +static size_t NumSuccessorsHelper(const LNode* ins) { return 0; } + +template <size_t Succs, size_t Operands, size_t Temps> +static size_t NumSuccessorsHelper( + const LControlInstructionHelper<Succs, Operands, Temps>* ins) { + return Succs; +} + +static size_t NumSuccessors(const LInstruction* ins) { + switch (ins->op()) { + default: + MOZ_CRASH("Unexpected LIR op"); +# define LIROP(x) \ + case LNode::Opcode::x: \ + return NumSuccessorsHelper(ins->to##x()); + LIR_OPCODE_LIST(LIROP) +# undef LIROP + } +} + +static MBasicBlock* GetSuccessorHelper(const LNode* ins, size_t i) { + MOZ_CRASH("Unexpected instruction with successors"); +} + +template <size_t Succs, size_t Operands, size_t Temps> +static MBasicBlock* GetSuccessorHelper( + const LControlInstructionHelper<Succs, Operands, Temps>* ins, size_t i) { + return ins->getSuccessor(i); +} + +static MBasicBlock* GetSuccessor(const LInstruction* ins, size_t i) { + MOZ_ASSERT(i < NumSuccessors(ins)); + + switch (ins->op()) { + default: + MOZ_CRASH("Unexpected LIR op"); +# define LIROP(x) \ + case LNode::Opcode::x: \ + return GetSuccessorHelper(ins->to##x(), i); + LIR_OPCODE_LIST(LIROP) +# undef LIROP + } +} +#endif + +#ifdef JS_JITSPEW +void LNode::dump(GenericPrinter& out) { + if (numDefs() != 0) { + out.printf("{"); + for (size_t i = 0; i < numDefs(); i++) { + const LDefinition* def = + isPhi() ? toPhi()->getDef(i) : toInstruction()->getDef(i); + out.printf("%s", def->toString().get()); + if (i != numDefs() - 1) { + out.printf(", "); + } + } + out.printf("} <- "); + } + + printName(out); + printOperands(out); + + if (isInstruction()) { + LInstruction* ins = toInstruction(); + size_t numTemps = ins->numTemps(); + if (numTemps > 0) { + out.printf(" t=("); + for (size_t i = 0; i < numTemps; i++) { + out.printf("%s", ins->getTemp(i)->toString().get()); + if (i != numTemps - 1) { + out.printf(", "); + } + } + out.printf(")"); + } + + size_t numSuccessors = NumSuccessors(ins); + if (numSuccessors > 0) { + out.printf(" s=("); + for (size_t i = 0; i < numSuccessors; i++) { + MBasicBlock* succ = GetSuccessor(ins, i); + out.printf("block%u", succ->id()); + if (i != numSuccessors - 1) { + out.printf(", "); + } + } + out.printf(")"); + } + } +} + +void LNode::dump() { + Fprinter out(stderr); + dump(out); + out.printf("\n"); + out.finish(); +} + +const char* LNode::getExtraName() const { + switch (op()) { + default: + MOZ_CRASH("Unexpected LIR op"); +# define LIROP(x) \ + case LNode::Opcode::x: \ + return to##x()->extraName(); + LIR_OPCODE_LIST(LIROP) +# undef LIROP + } +} +#endif + +void LInstruction::initSafepoint(TempAllocator& alloc) { + MOZ_ASSERT(!safepoint_); + safepoint_ = new (alloc) LSafepoint(alloc); + MOZ_ASSERT(safepoint_); +} + +bool LMoveGroup::add(LAllocation from, LAllocation to, LDefinition::Type type) { +#ifdef DEBUG + MOZ_ASSERT(from != to); + for (size_t i = 0; i < moves_.length(); i++) { + MOZ_ASSERT(to != moves_[i].to()); + } + + // Check that SIMD moves are aligned according to ABI requirements. + // clang-format off +# ifdef ENABLE_WASM_SIMD + // Alignment is not currently required for SIMD on x86/x64/arm64. See also + // CodeGeneratorShared::CodeGeneratorShared and in general everywhere + // SimdMemoryAignment is used. Likely, alignment requirements will return. +# if defined(JS_CODEGEN_X86) || defined(JS_CODEGEN_X64) || \ + defined(JS_CODEGEN_ARM64) + // No need for any check on x86/x64/arm64. +# else +# error "Need to consider SIMD alignment on this target." + // The following code may be of use if we need alignment checks on + // some future target. + //if (LDefinition(type).type() == LDefinition::SIMD128) { + // MOZ_ASSERT(from.isMemory() || from.isFloatReg()); + // if (from.isMemory()) { + // if (from.isArgument()) { + // MOZ_ASSERT(from.toArgument()->index() % SimdMemoryAlignment == 0); + // } else { + // MOZ_ASSERT(from.toStackSlot()->slot() % SimdMemoryAlignment == 0); + // } + // } + // MOZ_ASSERT(to.isMemory() || to.isFloatReg()); + // if (to.isMemory()) { + // if (to.isArgument()) { + // MOZ_ASSERT(to.toArgument()->index() % SimdMemoryAlignment == 0); + // } else { + // MOZ_ASSERT(to.toStackSlot()->slot() % SimdMemoryAlignment == 0); + // } + // } + //} +# endif +# endif + // clang-format on + +#endif + return moves_.append(LMove(from, to, type)); +} + +bool LMoveGroup::addAfter(LAllocation from, LAllocation to, + LDefinition::Type type) { + // Transform the operands to this move so that performing the result + // simultaneously with existing moves in the group will have the same + // effect as if the original move took place after the existing moves. + + for (size_t i = 0; i < moves_.length(); i++) { + if (moves_[i].to() == from) { + from = moves_[i].from(); + break; + } + } + + if (from == to) { + return true; + } + + for (size_t i = 0; i < moves_.length(); i++) { + if (to == moves_[i].to()) { + moves_[i] = LMove(from, to, type); + return true; + } + } + + return add(from, to, type); +} + +#ifdef JS_JITSPEW +void LMoveGroup::printOperands(GenericPrinter& out) { + for (size_t i = 0; i < numMoves(); i++) { + const LMove& move = getMove(i); + out.printf(" [%s -> %s", move.from().toString().get(), + move.to().toString().get()); + out.printf(", %s", DefTypeName(move.type())); + out.printf("]"); + if (i != numMoves() - 1) { + out.printf(","); + } + } +} +#endif + +#define LIROP(x) \ + static_assert(!std::is_polymorphic_v<L##x>, \ + "LIR instructions should not have virtual methods"); +LIR_OPCODE_LIST(LIROP) +#undef LIROP |