Source code

Revision control

Copy as Markdown

Other Tools

/* -*- 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/IonCacheIRCompiler.h"
#include "mozilla/Maybe.h"
#include <algorithm>
#include "jit/CacheIRCompiler.h"
#include "jit/CacheIRWriter.h"
#include "jit/IonIC.h"
#include "jit/JitcodeMap.h"
#include "jit/JitFrames.h"
#include "jit/JitRuntime.h"
#include "jit/JitZone.h"
#include "jit/JSJitFrameIter.h"
#include "jit/Linker.h"
#include "jit/SharedICHelpers.h"
#include "jit/VMFunctions.h"
#include "proxy/DeadObjectProxy.h"
#include "proxy/Proxy.h"
#include "util/Memory.h"
#include "vm/StaticStrings.h"
#include "jit/JSJitFrameIter-inl.h"
#include "jit/MacroAssembler-inl.h"
#include "jit/VMFunctionList-inl.h"
using namespace js;
using namespace js::jit;
using mozilla::Maybe;
namespace JS {
struct ExpandoAndGeneration;
}
using JS::ExpandoAndGeneration;
namespace js {
namespace jit {
// IonCacheIRCompiler compiles CacheIR to IonIC native code.
IonCacheIRCompiler::IonCacheIRCompiler(JSContext* cx, TempAllocator& alloc,
const CacheIRWriter& writer, IonIC* ic,
IonScript* ionScript,
uint32_t stubDataOffset)
: CacheIRCompiler(cx, alloc, writer, stubDataOffset, Mode::Ion,
StubFieldPolicy::Constant),
writer_(writer),
ic_(ic),
ionScript_(ionScript),
savedLiveRegs_(false),
localTracingSlots_(0),
perfSpewer_(ic->pc()) {
MOZ_ASSERT(ic_);
MOZ_ASSERT(ionScript_);
}
template <typename T>
T IonCacheIRCompiler::rawPointerStubField(uint32_t offset) {
static_assert(sizeof(T) == sizeof(uintptr_t), "T must have pointer size");
return (T)readStubWord(offset, StubField::Type::RawPointer);
}
template <typename T>
T IonCacheIRCompiler::rawInt64StubField(uint32_t offset) {
static_assert(sizeof(T) == sizeof(int64_t), "T musthave int64 size");
return (T)readStubInt64(offset, StubField::Type::RawInt64);
}
template <typename Fn, Fn fn>
void IonCacheIRCompiler::callVM(MacroAssembler& masm) {
VMFunctionId id = VMFunctionToId<Fn, fn>::id;
callVMInternal(masm, id);
}
void IonCacheIRCompiler::pushStubCodePointer() {
stubJitCodeOffset_.emplace(masm.PushWithPatch(ImmPtr((void*)-1)));
}
// AutoSaveLiveRegisters must be used when we make a call that can GC. The
// constructor ensures all live registers are stored on the stack (where the GC
// expects them) and the destructor restores these registers.
AutoSaveLiveRegisters::AutoSaveLiveRegisters(IonCacheIRCompiler& compiler)
: compiler_(compiler) {
MOZ_ASSERT(compiler_.liveRegs_.isSome());
MOZ_ASSERT(compiler_.ic_);
compiler_.allocator.saveIonLiveRegisters(
compiler_.masm, compiler_.liveRegs_.ref(),
compiler_.ic_->scratchRegisterForEntryJump(), compiler_.ionScript_);
compiler_.savedLiveRegs_ = true;
}
AutoSaveLiveRegisters::~AutoSaveLiveRegisters() {
MOZ_ASSERT(compiler_.stubJitCodeOffset_.isSome(),
"Must have pushed JitCode* pointer");
compiler_.allocator.restoreIonLiveRegisters(compiler_.masm,
compiler_.liveRegs_.ref());
MOZ_ASSERT(compiler_.masm.framePushed() == compiler_.ionScript_->frameSize());
}
} // namespace jit
} // namespace js
void CacheRegisterAllocator::saveIonLiveRegisters(MacroAssembler& masm,
LiveRegisterSet liveRegs,
Register scratch,
IonScript* ionScript) {
// We have to push all registers in liveRegs on the stack. It's possible we
// stored other values in our live registers and stored operands on the
// stack (where our live registers should go), so this requires some careful
// work. Try to keep it simple by taking one small step at a time.
// Step 1. Discard any dead operands so we can reuse their registers.
freeDeadOperandLocations(masm);
// Step 2. Figure out the size of our live regs. This is consistent with
// the fact that we're using storeRegsInMask to generate the save code and
// PopRegsInMask to generate the restore code.
size_t sizeOfLiveRegsInBytes =
MacroAssembler::PushRegsInMaskSizeInBytes(liveRegs);
MOZ_ASSERT(sizeOfLiveRegsInBytes > 0);
// Step 3. Ensure all non-input operands are on the stack.
size_t numInputs = writer_.numInputOperands();
for (size_t i = numInputs; i < operandLocations_.length(); i++) {
OperandLocation& loc = operandLocations_[i];
if (loc.isInRegister()) {
spillOperandToStack(masm, &loc);
}
}
// Step 4. Restore the register state, but don't discard the stack as
// non-input operands are stored there.
restoreInputState(masm, /* shouldDiscardStack = */ false);
// We just restored the input state, so no input operands should be stored
// on the stack.
#ifdef DEBUG
for (size_t i = 0; i < numInputs; i++) {
const OperandLocation& loc = operandLocations_[i];
MOZ_ASSERT(!loc.isOnStack());
}
#endif
// Step 5. At this point our register state is correct. Stack values,
// however, may cover the space where we have to store the live registers.
// Move them out of the way.
bool hasOperandOnStack = false;
for (size_t i = numInputs; i < operandLocations_.length(); i++) {
OperandLocation& loc = operandLocations_[i];
if (!loc.isOnStack()) {
continue;
}
hasOperandOnStack = true;
size_t operandSize = loc.stackSizeInBytes();
size_t operandStackPushed = loc.stackPushed();
MOZ_ASSERT(operandSize > 0);
MOZ_ASSERT(stackPushed_ >= operandStackPushed);
MOZ_ASSERT(operandStackPushed >= operandSize);
// If this operand doesn't cover the live register space, there's
// nothing to do.
if (operandStackPushed - operandSize >= sizeOfLiveRegsInBytes) {
MOZ_ASSERT(stackPushed_ > sizeOfLiveRegsInBytes);
continue;
}
// Reserve stack space for the live registers if needed.
if (sizeOfLiveRegsInBytes > stackPushed_) {
size_t extraBytes = sizeOfLiveRegsInBytes - stackPushed_;
MOZ_ASSERT((extraBytes % sizeof(uintptr_t)) == 0);
masm.subFromStackPtr(Imm32(extraBytes));
stackPushed_ += extraBytes;
}
// Push the operand below the live register space.
if (loc.kind() == OperandLocation::PayloadStack) {
masm.push(
Address(masm.getStackPointer(), stackPushed_ - operandStackPushed));
stackPushed_ += operandSize;
loc.setPayloadStack(stackPushed_, loc.payloadType());
continue;
}
MOZ_ASSERT(loc.kind() == OperandLocation::ValueStack);
masm.pushValue(
Address(masm.getStackPointer(), stackPushed_ - operandStackPushed));
stackPushed_ += operandSize;
loc.setValueStack(stackPushed_);
}
// Step 6. If we have any operands on the stack, adjust their stackPushed
// values to not include sizeOfLiveRegsInBytes (this simplifies code down
// the line). Then push/store the live registers.
if (hasOperandOnStack) {
MOZ_ASSERT(stackPushed_ > sizeOfLiveRegsInBytes);
stackPushed_ -= sizeOfLiveRegsInBytes;
for (size_t i = numInputs; i < operandLocations_.length(); i++) {
OperandLocation& loc = operandLocations_[i];
if (loc.isOnStack()) {
loc.adjustStackPushed(-int32_t(sizeOfLiveRegsInBytes));
}
}
size_t stackBottom = stackPushed_ + sizeOfLiveRegsInBytes;
masm.storeRegsInMask(liveRegs, Address(masm.getStackPointer(), stackBottom),
scratch);
masm.setFramePushed(masm.framePushed() + sizeOfLiveRegsInBytes);
} else {
// If no operands are on the stack, discard the unused stack space.
if (stackPushed_ > 0) {
masm.addToStackPtr(Imm32(stackPushed_));
stackPushed_ = 0;
}
masm.PushRegsInMask(liveRegs);
}
freePayloadSlots_.clear();
freeValueSlots_.clear();
MOZ_ASSERT(masm.framePushed() ==
ionScript->frameSize() + sizeOfLiveRegsInBytes);
// Step 7. All live registers and non-input operands are stored on the stack
// now, so at this point all registers except for the input registers are
// available.
availableRegs_.set() = GeneralRegisterSet::Not(inputRegisterSet());
availableRegsAfterSpill_.set() = GeneralRegisterSet();
// Step 8. We restored our input state, so we have to fix up aliased input
// registers again.
fixupAliasedInputs(masm);
}
void CacheRegisterAllocator::restoreIonLiveRegisters(MacroAssembler& masm,
LiveRegisterSet liveRegs) {
masm.PopRegsInMask(liveRegs);
availableRegs_.set() = GeneralRegisterSet();
availableRegsAfterSpill_.set() = GeneralRegisterSet::All();
}
static void* GetReturnAddressToIonCode(JSContext* cx) {
JSJitFrameIter frame(cx->activation()->asJit());
MOZ_ASSERT(frame.type() == FrameType::Exit,
"An exit frame is expected as update functions are called with a "
"VMFunction.");
void* returnAddr = frame.returnAddress();
#ifdef DEBUG
++frame;
MOZ_ASSERT(frame.isIonJS());
#endif
return returnAddr;
}
// The AutoSaveLiveRegisters parameter is used to ensure registers were saved
void IonCacheIRCompiler::enterStubFrame(MacroAssembler& masm,
const AutoSaveLiveRegisters&) {
MOZ_ASSERT(!enteredStubFrame_);
pushStubCodePointer();
masm.PushFrameDescriptor(FrameType::IonJS);
masm.Push(ImmPtr(GetReturnAddressToIonCode(cx_)));
masm.Push(FramePointer);
masm.moveStackPtrTo(FramePointer);
enteredStubFrame_ = true;
}
void IonCacheIRCompiler::storeTracedValue(MacroAssembler& masm,
ValueOperand value) {
MOZ_ASSERT(localTracingSlots_ < 255);
masm.Push(value);
localTracingSlots_++;
}
void IonCacheIRCompiler::loadTracedValue(MacroAssembler& masm,
uint8_t slotIndex,
ValueOperand value) {
MOZ_ASSERT(slotIndex <= localTracingSlots_);
int32_t offset = IonICCallFrameLayout::LocallyTracedValueOffset +
slotIndex * sizeof(Value);
masm.loadValue(Address(FramePointer, -offset), value);
}
bool IonCacheIRCompiler::init() {
if (!allocator.init()) {
return false;
}
size_t numInputs = writer_.numInputOperands();
MOZ_ASSERT(numInputs == NumInputsForCacheKind(ic_->kind()));
AllocatableGeneralRegisterSet available;
switch (ic_->kind()) {
case CacheKind::GetProp:
case CacheKind::GetElem: {
IonGetPropertyIC* ic = ic_->asGetPropertyIC();
ValueOperand output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(output);
MOZ_ASSERT(numInputs == 1 || numInputs == 2);
allocator.initInputLocation(0, ic->value());
if (numInputs > 1) {
allocator.initInputLocation(1, ic->id());
}
break;
}
case CacheKind::GetPropSuper:
case CacheKind::GetElemSuper: {
IonGetPropSuperIC* ic = ic_->asGetPropSuperIC();
ValueOperand output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(output);
MOZ_ASSERT(numInputs == 2 || numInputs == 3);
allocator.initInputLocation(0, ic->object(), JSVAL_TYPE_OBJECT);
if (ic->kind() == CacheKind::GetPropSuper) {
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(1, ic->receiver());
} else {
MOZ_ASSERT(numInputs == 3);
allocator.initInputLocation(1, ic->id());
allocator.initInputLocation(2, ic->receiver());
}
break;
}
case CacheKind::SetProp:
case CacheKind::SetElem: {
IonSetPropertyIC* ic = ic_->asSetPropertyIC();
available.add(ic->temp());
liveRegs_.emplace(ic->liveRegs());
allocator.initInputLocation(0, ic->object(), JSVAL_TYPE_OBJECT);
if (ic->kind() == CacheKind::SetProp) {
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(1, ic->rhs());
} else {
MOZ_ASSERT(numInputs == 3);
allocator.initInputLocation(1, ic->id());
allocator.initInputLocation(2, ic->rhs());
}
break;
}
case CacheKind::GetName: {
IonGetNameIC* ic = ic_->asGetNameIC();
ValueOperand output = ic->output();
available.add(output);
available.add(ic->temp());
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(output);
MOZ_ASSERT(numInputs == 1);
allocator.initInputLocation(0, ic->environment(), JSVAL_TYPE_OBJECT);
break;
}
case CacheKind::BindName: {
IonBindNameIC* ic = ic_->asBindNameIC();
Register output = ic->output();
available.add(output);
available.add(ic->temp());
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Object, AnyRegister(output)));
MOZ_ASSERT(numInputs == 1);
allocator.initInputLocation(0, ic->environment(), JSVAL_TYPE_OBJECT);
break;
}
case CacheKind::GetIterator: {
IonGetIteratorIC* ic = ic_->asGetIteratorIC();
Register output = ic->output();
available.add(output);
available.add(ic->temp1());
available.add(ic->temp2());
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Object, AnyRegister(output)));
MOZ_ASSERT(numInputs == 1);
allocator.initInputLocation(0, ic->value());
break;
}
case CacheKind::OptimizeSpreadCall: {
auto* ic = ic_->asOptimizeSpreadCallIC();
ValueOperand output = ic->output();
available.add(output);
available.add(ic->temp());
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(output);
MOZ_ASSERT(numInputs == 1);
allocator.initInputLocation(0, ic->value());
break;
}
case CacheKind::In: {
IonInIC* ic = ic_->asInIC();
Register output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Boolean, AnyRegister(output)));
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(0, ic->key());
allocator.initInputLocation(
1, TypedOrValueRegister(MIRType::Object, AnyRegister(ic->object())));
break;
}
case CacheKind::HasOwn: {
IonHasOwnIC* ic = ic_->asHasOwnIC();
Register output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Boolean, AnyRegister(output)));
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(0, ic->id());
allocator.initInputLocation(1, ic->value());
break;
}
case CacheKind::CheckPrivateField: {
IonCheckPrivateFieldIC* ic = ic_->asCheckPrivateFieldIC();
Register output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Boolean, AnyRegister(output)));
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(0, ic->value());
allocator.initInputLocation(1, ic->id());
break;
}
case CacheKind::InstanceOf: {
IonInstanceOfIC* ic = ic_->asInstanceOfIC();
Register output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Boolean, AnyRegister(output)));
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(0, ic->lhs());
allocator.initInputLocation(
1, TypedOrValueRegister(MIRType::Object, AnyRegister(ic->rhs())));
break;
}
case CacheKind::ToPropertyKey: {
IonToPropertyKeyIC* ic = ic_->asToPropertyKeyIC();
ValueOperand output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(TypedOrValueRegister(output));
MOZ_ASSERT(numInputs == 1);
allocator.initInputLocation(0, ic->input());
break;
}
case CacheKind::UnaryArith: {
IonUnaryArithIC* ic = ic_->asUnaryArithIC();
ValueOperand output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(TypedOrValueRegister(output));
MOZ_ASSERT(numInputs == 1);
allocator.initInputLocation(0, ic->input());
break;
}
case CacheKind::BinaryArith: {
IonBinaryArithIC* ic = ic_->asBinaryArithIC();
ValueOperand output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(TypedOrValueRegister(output));
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(0, ic->lhs());
allocator.initInputLocation(1, ic->rhs());
break;
}
case CacheKind::Compare: {
IonCompareIC* ic = ic_->asCompareIC();
Register output = ic->output();
available.add(output);
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Boolean, AnyRegister(output)));
MOZ_ASSERT(numInputs == 2);
allocator.initInputLocation(0, ic->lhs());
allocator.initInputLocation(1, ic->rhs());
break;
}
case CacheKind::CloseIter: {
IonCloseIterIC* ic = ic_->asCloseIterIC();
available.add(ic->temp());
liveRegs_.emplace(ic->liveRegs());
allocator.initInputLocation(0, ic->iter(), JSVAL_TYPE_OBJECT);
break;
}
case CacheKind::OptimizeGetIterator: {
auto* ic = ic_->asOptimizeGetIteratorIC();
Register output = ic->output();
available.add(output);
available.add(ic->temp());
liveRegs_.emplace(ic->liveRegs());
outputUnchecked_.emplace(
TypedOrValueRegister(MIRType::Boolean, AnyRegister(output)));
MOZ_ASSERT(numInputs == 1);
allocator.initInputLocation(0, ic->value());
break;
}
case CacheKind::Call:
case CacheKind::TypeOf:
case CacheKind::TypeOfEq:
case CacheKind::ToBool:
case CacheKind::GetIntrinsic:
case CacheKind::NewArray:
case CacheKind::NewObject:
MOZ_CRASH("Unsupported IC");
}
liveFloatRegs_ = LiveFloatRegisterSet(liveRegs_->fpus());
allocator.initAvailableRegs(available);
allocator.initAvailableRegsAfterSpill();
return true;
}
JitCode* IonCacheIRCompiler::compile(IonICStub* stub) {
AutoCreatedBy acb(masm, "IonCacheIRCompiler::compile");
masm.setFramePushed(ionScript_->frameSize());
if (cx_->runtime()->geckoProfiler().enabled()) {
masm.enableProfilingInstrumentation();
}
allocator.fixupAliasedInputs(masm);
CacheIRReader reader(writer_);
do {
CacheOp op = reader.readOp();
perfSpewer_.recordInstruction(masm, op);
switch (op) {
#define DEFINE_OP(op, ...) \
case CacheOp::op: \
if (!emit##op(reader)) return nullptr; \
break;
CACHE_IR_OPS(DEFINE_OP)
#undef DEFINE_OP
default:
MOZ_CRASH("Invalid op");
}
allocator.nextOp();
} while (reader.more());
masm.assumeUnreachable("Should have returned from IC");
// Done emitting the main IC code. Now emit the failure paths.
for (size_t i = 0; i < failurePaths.length(); i++) {
if (!emitFailurePath(i)) {
return nullptr;
}
Register scratch = ic_->scratchRegisterForEntryJump();
CodeOffset offset = masm.movWithPatch(ImmWord(-1), scratch);
masm.jump(Address(scratch, 0));
if (!nextCodeOffsets_.append(offset)) {
return nullptr;
}
}
Linker linker(masm);
Rooted<JitCode*> newStubCode(cx_, linker.newCode(cx_, CodeKind::Ion));
if (!newStubCode) {
cx_->recoverFromOutOfMemory();
return nullptr;
}
newStubCode->setLocalTracingSlots(localTracingSlots_);
for (CodeOffset offset : nextCodeOffsets_) {
Assembler::PatchDataWithValueCheck(CodeLocationLabel(newStubCode, offset),
ImmPtr(stub->nextCodeRawPtr()),
ImmPtr((void*)-1));
}
if (stubJitCodeOffset_) {
Assembler::PatchDataWithValueCheck(
CodeLocationLabel(newStubCode, *stubJitCodeOffset_),
ImmPtr(newStubCode.get()), ImmPtr((void*)-1));
}
return newStubCode;
}
#ifdef DEBUG
void IonCacheIRCompiler::assertFloatRegisterAvailable(FloatRegister reg) {
switch (ic_->kind()) {
case CacheKind::GetProp:
case CacheKind::GetElem:
case CacheKind::GetPropSuper:
case CacheKind::GetElemSuper:
case CacheKind::GetName:
case CacheKind::BindName:
case CacheKind::GetIterator:
case CacheKind::In:
case CacheKind::HasOwn:
case CacheKind::CheckPrivateField:
case CacheKind::InstanceOf:
case CacheKind::UnaryArith:
case CacheKind::ToPropertyKey:
case CacheKind::OptimizeSpreadCall:
case CacheKind::CloseIter:
case CacheKind::OptimizeGetIterator:
MOZ_CRASH("No float registers available");
case CacheKind::SetProp:
case CacheKind::SetElem:
// FloatReg0 is available per LIRGenerator::visitSetPropertyCache.
MOZ_ASSERT(reg == FloatReg0);
break;
case CacheKind::BinaryArith:
case CacheKind::Compare:
// FloatReg0 and FloatReg1 are available per
// LIRGenerator::visitBinaryCache.
MOZ_ASSERT(reg == FloatReg0 || reg == FloatReg1);
break;
case CacheKind::Call:
case CacheKind::TypeOf:
case CacheKind::TypeOfEq:
case CacheKind::ToBool:
case CacheKind::GetIntrinsic:
case CacheKind::NewArray:
case CacheKind::NewObject:
MOZ_CRASH("Unsupported IC");
}
}
#endif
bool IonCacheIRCompiler::emitGuardShape(ObjOperandId objId,
uint32_t shapeOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
Shape* shape = weakShapeStubField(shapeOffset);
bool needSpectreMitigations = objectGuardNeedsSpectreMitigations(objId);
Maybe<AutoScratchRegister> maybeScratch;
if (needSpectreMitigations) {
maybeScratch.emplace(allocator, masm);
}
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
if (needSpectreMitigations) {
masm.branchTestObjShape(Assembler::NotEqual, obj, shape, *maybeScratch, obj,
failure->label());
} else {
masm.branchTestObjShapeNoSpectreMitigations(Assembler::NotEqual, obj, shape,
failure->label());
}
return true;
}
bool IonCacheIRCompiler::emitGuardProto(ObjOperandId objId,
uint32_t protoOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
JSObject* proto = weakObjectStubField(protoOffset);
AutoScratchRegister scratch(allocator, masm);
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
masm.loadObjProto(obj, scratch);
masm.branchPtr(Assembler::NotEqual, scratch, ImmGCPtr(proto),
failure->label());
return true;
}
bool IonCacheIRCompiler::emitGuardCompartment(ObjOperandId objId,
uint32_t globalOffset,
uint32_t compartmentOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
JSObject* globalWrapper = objectStubField(globalOffset);
JS::Compartment* compartment = compartmentStubField(compartmentOffset);
AutoScratchRegister scratch(allocator, masm);
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
// Verify that the global wrapper is still valid, as
// it is pre-requisite for doing the compartment check.
masm.movePtr(ImmGCPtr(globalWrapper), scratch);
Address handlerAddr(scratch, ProxyObject::offsetOfHandler());
masm.branchPtr(Assembler::Equal, handlerAddr,
ImmPtr(&DeadObjectProxy::singleton), failure->label());
masm.branchTestObjCompartment(Assembler::NotEqual, obj, compartment, scratch,
failure->label());
return true;
}
bool IonCacheIRCompiler::emitGuardAnyClass(ObjOperandId objId,
uint32_t claspOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
AutoScratchRegister scratch(allocator, masm);
const JSClass* clasp = classStubField(claspOffset);
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
if (objectGuardNeedsSpectreMitigations(objId)) {
masm.branchTestObjClass(Assembler::NotEqual, obj, clasp, scratch, obj,
failure->label());
} else {
masm.branchTestObjClassNoSpectreMitigations(Assembler::NotEqual, obj, clasp,
scratch, failure->label());
}
return true;
}
bool IonCacheIRCompiler::emitGuardHasProxyHandler(ObjOperandId objId,
uint32_t handlerOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
const void* handler = proxyHandlerStubField(handlerOffset);
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
Address handlerAddr(obj, ProxyObject::offsetOfHandler());
masm.branchPtr(Assembler::NotEqual, handlerAddr, ImmPtr(handler),
failure->label());
return true;
}
bool IonCacheIRCompiler::emitGuardSpecificObject(ObjOperandId objId,
uint32_t expectedOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
JSObject* expected = weakObjectStubField(expectedOffset);
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
masm.branchPtr(Assembler::NotEqual, obj, ImmGCPtr(expected),
failure->label());
return true;
}
bool IonCacheIRCompiler::emitGuardSpecificFunction(
ObjOperandId objId, uint32_t expectedOffset, uint32_t nargsAndFlagsOffset) {
return emitGuardSpecificObject(objId, expectedOffset);
}
bool IonCacheIRCompiler::emitGuardSpecificAtom(StringOperandId strId,
uint32_t expectedOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register str = allocator.useRegister(masm, strId);
AutoScratchRegister scratch(allocator, masm);
JSAtom* atom = &stringStubField(expectedOffset)->asAtom();
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
LiveRegisterSet volatileRegs = liveVolatileRegs();
volatileRegs.takeUnchecked(scratch);
masm.guardSpecificAtom(str, atom, scratch, volatileRegs, failure->label());
return true;
}
bool IonCacheIRCompiler::emitGuardSpecificSymbol(SymbolOperandId symId,
uint32_t expectedOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register sym = allocator.useRegister(masm, symId);
JS::Symbol* expected = symbolStubField(expectedOffset);
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
masm.branchPtr(Assembler::NotEqual, sym, ImmGCPtr(expected),
failure->label());
return true;
}
bool IonCacheIRCompiler::emitLoadValueResult(uint32_t valOffset) {
MOZ_CRASH("Baseline-specific op");
}
bool IonCacheIRCompiler::emitLoadFixedSlotResult(ObjOperandId objId,
uint32_t offsetOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoOutputRegister output(*this);
Register obj = allocator.useRegister(masm, objId);
int32_t offset = int32StubField(offsetOffset);
masm.loadTypedOrValue(Address(obj, offset), output);
return true;
}
bool IonCacheIRCompiler::emitLoadFixedSlotTypedResult(ObjOperandId objId,
uint32_t offsetOffset,
ValueType) {
MOZ_CRASH("Call ICs not used in ion");
}
bool IonCacheIRCompiler::emitLoadDynamicSlotResult(ObjOperandId objId,
uint32_t offsetOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoOutputRegister output(*this);
Register obj = allocator.useRegister(masm, objId);
int32_t offset = int32StubField(offsetOffset);
AutoScratchRegisterMaybeOutput scratch(allocator, masm, output);
masm.loadPtr(Address(obj, NativeObject::offsetOfSlots()), scratch);
masm.loadTypedOrValue(Address(scratch, offset), output);
return true;
}
bool IonCacheIRCompiler::emitCallScriptedGetterResult(
ValOperandId receiverId, uint32_t getterOffset, bool sameRealm,
uint32_t nargsAndFlagsOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
AutoOutputRegister output(*this);
ValueOperand receiver = allocator.useValueRegister(masm, receiverId);
JSFunction* target = &objectStubField(getterOffset)->as<JSFunction>();
AutoScratchRegister scratch(allocator, masm);
MOZ_ASSERT(sameRealm == (cx_->realm() == target->realm()));
allocator.discardStack(masm);
uint32_t framePushedBefore = masm.framePushed();
enterStubFrame(masm, save);
// The JitFrameLayout pushed below will be aligned to JitStackAlignment,
// so we just have to make sure the stack is aligned after we push the
// |this| + argument Values.
uint32_t argSize = (target->nargs() + 1) * sizeof(Value);
uint32_t padding =
ComputeByteAlignment(masm.framePushed() + argSize, JitStackAlignment);
MOZ_ASSERT(padding % sizeof(uintptr_t) == 0);
MOZ_ASSERT(padding < JitStackAlignment);
masm.reserveStack(padding);
for (size_t i = 0; i < target->nargs(); i++) {
masm.Push(UndefinedValue());
}
masm.Push(receiver);
if (!sameRealm) {
masm.switchToRealm(target->realm(), scratch);
}
masm.movePtr(ImmGCPtr(target), scratch);
masm.Push(scratch);
masm.PushFrameDescriptorForJitCall(FrameType::IonICCall, /* argc = */ 0);
// Check stack alignment. Add 2 * sizeof(uintptr_t) for the return address and
// frame pointer pushed by the call/callee.
MOZ_ASSERT(
((masm.framePushed() + 2 * sizeof(uintptr_t)) % JitStackAlignment) == 0);
MOZ_ASSERT(target->hasJitEntry());
masm.loadJitCodeRaw(scratch, scratch);
masm.callJit(scratch);
if (!sameRealm) {
static_assert(!JSReturnOperand.aliases(ReturnReg),
"ReturnReg available as scratch after scripted calls");
masm.switchToRealm(cx_->realm(), ReturnReg);
}
masm.storeCallResultValue(output);
// Restore the frame pointer and stack pointer.
masm.loadPtr(Address(FramePointer, 0), FramePointer);
masm.freeStack(masm.framePushed() - framePushedBefore);
return true;
}
#ifdef JS_PUNBOX64
template <typename IdType>
bool IonCacheIRCompiler::emitCallScriptedProxyGetShared(
ValOperandId targetId, ObjOperandId receiverId, ObjOperandId handlerId,
ObjOperandId trapId, IdType id, uint32_t nargsAndFlags) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
AutoOutputRegister output(*this);
ValueOperand target = allocator.useValueRegister(masm, targetId);
Register receiver = allocator.useRegister(masm, receiverId);
Register handler = allocator.useRegister(masm, handlerId);
Register callee = allocator.useRegister(masm, trapId);
ValueOperand idVal;
if constexpr (std::is_same_v<IdType, ValOperandId>) {
idVal = allocator.useValueRegister(masm, id);
}
size_t nargs = nargsAndFlags >> JSFunction::ArgCountShift;
AutoScratchRegister scratch(allocator, masm);
AutoScratchRegister scratch2(allocator, masm);
ValueOperand scratchVal(scratch);
ValueOperand scratchVal2(scratch2);
allocator.discardStack(masm);
uint32_t framePushedBefore = masm.framePushed();
enterStubFrame(masm, save);
// We need to keep the target around to potentially validate the proxy result
storeTracedValue(masm, target);
if constexpr (std::is_same_v<IdType, ValOperandId>) {
// Same for the id, assuming it's not baked in
storeTracedValue(masm, idVal);
}
uint32_t framePushedBeforeArgs = masm.framePushed();
// The JitFrameLayout pushed below will be aligned to JitStackAlignment,
// so we just have to make sure the stack is aligned after we push the
// |this| + argument Values.
uint32_t argSize = (std::max(nargs, (size_t)3) + 1) * sizeof(Value);
uint32_t padding =
ComputeByteAlignment(masm.framePushed() + argSize, JitStackAlignment);
MOZ_ASSERT(padding % sizeof(uintptr_t) == 0);
MOZ_ASSERT(padding < JitStackAlignment);
masm.reserveStack(padding);
for (size_t i = 3; i < nargs; i++) {
masm.Push(UndefinedValue());
}
masm.tagValue(JSVAL_TYPE_OBJECT, receiver, scratchVal);
masm.Push(scratchVal);
if constexpr (std::is_same_v<IdType, ValOperandId>) {
masm.Push(idVal);
} else {
masm.movePropertyKey(idStubField(id), scratch);
masm.tagValue(JSVAL_TYPE_STRING, scratch, scratchVal);
masm.Push(scratchVal);
}
masm.Push(target);
masm.tagValue(JSVAL_TYPE_OBJECT, handler, scratchVal);
masm.Push(scratchVal);
masm.Push(callee);
masm.PushFrameDescriptorForJitCall(FrameType::IonICCall, /* argc = */ 3);
// Check stack alignment. Add 2 * sizeof(uintptr_t) for the return address and
// frame pointer pushed by the call/callee.
MOZ_ASSERT(
((masm.framePushed() + 2 * sizeof(uintptr_t)) % JitStackAlignment) == 0);
masm.loadJitCodeRaw(callee, scratch);
masm.callJit(scratch);
masm.storeCallResultValue(output);
Label success, end;
loadTracedValue(masm, 0, scratchVal);
masm.unboxObject(scratchVal, scratch);
masm.branchTestObjectNeedsProxyResultValidation(Assembler::Zero, scratch,
scratch2, &success);
if constexpr (std::is_same_v<IdType, ValOperandId>) {
loadTracedValue(masm, 1, scratchVal2);
} else {
masm.moveValue(StringValue(idStubField(id).toString()), scratchVal2);
}
uint32_t framePushedAfterCall = masm.framePushed();
masm.freeStack(masm.framePushed() - framePushedBeforeArgs);
masm.Push(output.valueReg());
masm.Push(scratchVal2);
masm.Push(scratch);
using Fn = bool (*)(JSContext*, HandleObject, HandleValue, HandleValue,
MutableHandleValue);
callVM<Fn, CheckProxyGetByValueResult>(masm);
masm.storeCallResultValue(output);
masm.jump(&end);
masm.bind(&success);
masm.setFramePushed(framePushedAfterCall);
// Restore the frame pointer and stack pointer.
masm.loadPtr(Address(FramePointer, 0), FramePointer);
masm.freeStack(masm.framePushed() - framePushedBefore);
masm.bind(&end);
return true;
}
bool IonCacheIRCompiler::emitCallScriptedProxyGetResult(
ValOperandId targetId, ObjOperandId receiverId, ObjOperandId handlerId,
ObjOperandId trapId, uint32_t id, uint32_t nargsAndFlags) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
return emitCallScriptedProxyGetShared(targetId, receiverId, handlerId, trapId,
id, nargsAndFlags);
}
bool IonCacheIRCompiler::emitCallScriptedProxyGetByValueResult(
ValOperandId targetId, ObjOperandId receiverId, ObjOperandId handlerId,
ValOperandId idId, ObjOperandId trapId, uint32_t nargsAndFlags) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
return emitCallScriptedProxyGetShared(targetId, receiverId, handlerId, trapId,
idId, nargsAndFlags);
}
#endif
bool IonCacheIRCompiler::emitCallInlinedGetterResult(
ValOperandId receiverId, uint32_t getterOffset, uint32_t icScriptOffset,
bool sameRealm, uint32_t nargsAndFlagsOffset) {
MOZ_CRASH("Trial inlining not supported in Ion");
}
bool IonCacheIRCompiler::emitCallNativeGetterResult(
ValOperandId receiverId, uint32_t getterOffset, bool sameRealm,
uint32_t nargsAndFlagsOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
AutoOutputRegister output(*this);
ValueOperand receiver = allocator.useValueRegister(masm, receiverId);
JSFunction* target = &objectStubField(getterOffset)->as<JSFunction>();
MOZ_ASSERT(target->isNativeFun());
AutoScratchRegisterMaybeOutput argJSContext(allocator, masm, output);
AutoScratchRegisterMaybeOutputType argUintN(allocator, masm, output);
AutoScratchRegister argVp(allocator, masm);
AutoScratchRegister scratch(allocator, masm);
allocator.discardStack(masm);
// Native functions have the signature:
// bool (*)(JSContext*, unsigned, Value* vp)
// Where vp[0] is space for an outparam, vp[1] is |this|, and vp[2] onward
// are the function arguments.
// Construct vp array:
// Push receiver value for |this|
masm.Push(receiver);
// Push callee/outparam.
masm.Push(ObjectValue(*target));
// Preload arguments into registers.
masm.loadJSContext(argJSContext);
masm.move32(Imm32(0), argUintN);
masm.moveStackPtrTo(argVp.get());
// Push marking data for later use.
masm.Push(argUintN);
pushStubCodePointer();
if (!masm.icBuildOOLFakeExitFrame(GetReturnAddressToIonCode(cx_), save)) {
return false;
}
masm.enterFakeExitFrame(argJSContext, scratch, ExitFrameType::IonOOLNative);
if (!sameRealm) {
masm.switchToRealm(target->realm(), scratch);
}
// Construct and execute call.
masm.setupUnalignedABICall(scratch);
masm.passABIArg(argJSContext);
masm.passABIArg(argUintN);
masm.passABIArg(argVp);
masm.callWithABI(DynamicFunction<JSNative>(target->native()),
ABIType::General,
CheckUnsafeCallWithABI::DontCheckHasExitFrame);
// Test for failure.
masm.branchIfFalseBool(ReturnReg, masm.exceptionLabel());
if (!sameRealm) {
masm.switchToRealm(cx_->realm(), ReturnReg);
}
// Load the outparam vp[0] into output register(s).
Address outparam(masm.getStackPointer(),
IonOOLNativeExitFrameLayout::offsetOfResult());
masm.loadValue(outparam, output.valueReg());
if (JitOptions.spectreJitToCxxCalls) {
masm.speculationBarrier();
}
masm.adjustStack(IonOOLNativeExitFrameLayout::Size(0));
return true;
}
bool IonCacheIRCompiler::emitCallDOMGetterResult(ObjOperandId objId,
uint32_t jitInfoOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
AutoOutputRegister output(*this);
Register obj = allocator.useRegister(masm, objId);
const JSJitInfo* info = rawPointerStubField<const JSJitInfo*>(jitInfoOffset);
allocator.discardStack(masm);
enterStubFrame(masm, save);
masm.Push(obj);
masm.Push(ImmPtr(info));
using Fn =
bool (*)(JSContext*, const JSJitInfo*, HandleObject, MutableHandleValue);
callVM<Fn, jit::CallDOMGetter>(masm);
masm.storeCallResultValue(output);
return true;
}
bool IonCacheIRCompiler::emitCallDOMSetter(ObjOperandId objId,
uint32_t jitInfoOffset,
ValOperandId rhsId) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
Register obj = allocator.useRegister(masm, objId);
ValueOperand val = allocator.useValueRegister(masm, rhsId);
const JSJitInfo* info = rawPointerStubField<const JSJitInfo*>(jitInfoOffset);
allocator.discardStack(masm);
enterStubFrame(masm, save);
masm.Push(val);
masm.Push(obj);
masm.Push(ImmPtr(info));
using Fn = bool (*)(JSContext*, const JSJitInfo*, HandleObject, HandleValue);
callVM<Fn, jit::CallDOMSetter>(masm);
return true;
}
bool IonCacheIRCompiler::emitProxyGetResult(ObjOperandId objId,
uint32_t idOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
AutoOutputRegister output(*this);
Register obj = allocator.useRegister(masm, objId);
jsid id = idStubField(idOffset);
// ProxyGetProperty(JSContext* cx, HandleObject proxy, HandleId id,
// MutableHandleValue vp)
AutoScratchRegisterMaybeOutput argJSContext(allocator, masm, output);
AutoScratchRegisterMaybeOutputType argProxy(allocator, masm, output);
AutoScratchRegister argId(allocator, masm);
AutoScratchRegister argVp(allocator, masm);
AutoScratchRegister scratch(allocator, masm);
allocator.discardStack(masm);
// Push stubCode for marking.
pushStubCodePointer();
// Push args on stack first so we can take pointers to make handles.
masm.Push(UndefinedValue());
masm.moveStackPtrTo(argVp.get());
masm.Push(id, scratch);
masm.moveStackPtrTo(argId.get());
// Push the proxy. Also used as receiver.
masm.Push(obj);
masm.moveStackPtrTo(argProxy.get());
masm.loadJSContext(argJSContext);
if (!masm.icBuildOOLFakeExitFrame(GetReturnAddressToIonCode(cx_), save)) {
return false;
}
masm.enterFakeExitFrame(argJSContext, scratch, ExitFrameType::IonOOLProxy);
// Make the call.
using Fn = bool (*)(JSContext* cx, HandleObject proxy, HandleId id,
MutableHandleValue vp);
masm.setupUnalignedABICall(scratch);
masm.passABIArg(argJSContext);
masm.passABIArg(argProxy);
masm.passABIArg(argId);
masm.passABIArg(argVp);
masm.callWithABI<Fn, ProxyGetProperty>(
ABIType::General, CheckUnsafeCallWithABI::DontCheckHasExitFrame);
// Test for failure.
masm.branchIfFalseBool(ReturnReg, masm.exceptionLabel());
// Load the outparam vp[0] into output register(s).
Address outparam(masm.getStackPointer(),
IonOOLProxyExitFrameLayout::offsetOfResult());
masm.loadValue(outparam, output.valueReg());
// Spectre mitigation in case of speculative execution within C++ code.
if (JitOptions.spectreJitToCxxCalls) {
masm.speculationBarrier();
}
// masm.leaveExitFrame & pop locals
masm.adjustStack(IonOOLProxyExitFrameLayout::Size());
return true;
}
bool IonCacheIRCompiler::emitFrameIsConstructingResult() {
MOZ_CRASH("Baseline-specific op");
}
bool IonCacheIRCompiler::emitLoadConstantStringResult(uint32_t strOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
MOZ_CRASH("not used in ion");
}
bool IonCacheIRCompiler::emitCompareStringResult(JSOp op, StringOperandId lhsId,
StringOperandId rhsId) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
AutoOutputRegister output(*this);
Register left = allocator.useRegister(masm, lhsId);
Register right = allocator.useRegister(masm, rhsId);
allocator.discardStack(masm);
Label slow, done;
MOZ_ASSERT(!output.hasValue());
masm.compareStrings(op, left, right, output.typedReg().gpr(), &slow);
masm.jump(&done);
masm.bind(&slow);
enterStubFrame(masm, save);
// Push the operands in reverse order for JSOp::Le and JSOp::Gt:
// - |left <= right| is implemented as |right >= left|.
// - |left > right| is implemented as |right < left|.
if (op == JSOp::Le || op == JSOp::Gt) {
masm.Push(left);
masm.Push(right);
} else {
masm.Push(right);
masm.Push(left);
}
using Fn = bool (*)(JSContext*, HandleString, HandleString, bool*);
if (op == JSOp::Eq || op == JSOp::StrictEq) {
callVM<Fn, jit::StringsEqual<EqualityKind::Equal>>(masm);
} else if (op == JSOp::Ne || op == JSOp::StrictNe) {
callVM<Fn, jit::StringsEqual<EqualityKind::NotEqual>>(masm);
} else if (op == JSOp::Lt || op == JSOp::Gt) {
callVM<Fn, jit::StringsCompare<ComparisonKind::LessThan>>(masm);
} else {
MOZ_ASSERT(op == JSOp::Le || op == JSOp::Ge);
callVM<Fn, jit::StringsCompare<ComparisonKind::GreaterThanOrEqual>>(masm);
}
masm.storeCallBoolResult(output.typedReg().gpr());
masm.bind(&done);
return true;
}
bool IonCacheIRCompiler::emitStoreFixedSlot(ObjOperandId objId,
uint32_t offsetOffset,
ValOperandId rhsId) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
int32_t offset = int32StubField(offsetOffset);
ConstantOrRegister val = allocator.useConstantOrRegister(masm, rhsId);
AutoScratchRegister scratch(allocator, masm);
Address slot(obj, offset);
EmitPreBarrier(masm, slot, MIRType::Value);
masm.storeConstantOrRegister(val, slot);
emitPostBarrierSlot(obj, val, scratch);
return true;
}
bool IonCacheIRCompiler::emitStoreDynamicSlot(ObjOperandId objId,
uint32_t offsetOffset,
ValOperandId rhsId) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
int32_t offset = int32StubField(offsetOffset);
ConstantOrRegister val = allocator.useConstantOrRegister(masm, rhsId);
AutoScratchRegister scratch(allocator, masm);
masm.loadPtr(Address(obj, NativeObject::offsetOfSlots()), scratch);
Address slot(scratch, offset);
EmitPreBarrier(masm, slot, MIRType::Value);
masm.storeConstantOrRegister(val, slot);
emitPostBarrierSlot(obj, val, scratch);
return true;
}
bool IonCacheIRCompiler::emitAddAndStoreSlotShared(
CacheOp op, ObjOperandId objId, uint32_t offsetOffset, ValOperandId rhsId,
uint32_t newShapeOffset, Maybe<uint32_t> numNewSlotsOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Register obj = allocator.useRegister(masm, objId);
int32_t offset = int32StubField(offsetOffset);
ConstantOrRegister val = allocator.useConstantOrRegister(masm, rhsId);
AutoScratchRegister scratch1(allocator, masm);
Maybe<AutoScratchRegister> scratch2;
if (op == CacheOp::AllocateAndStoreDynamicSlot) {
scratch2.emplace(allocator, masm);
}
Shape* newShape = shapeStubField(newShapeOffset);
if (op == CacheOp::AllocateAndStoreDynamicSlot) {
// We have to (re)allocate dynamic slots. Do this first, as it's the
// only fallible operation here. Note that growSlotsPure is
// fallible but does not GC.
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
int32_t numNewSlots = int32StubField(*numNewSlotsOffset);
MOZ_ASSERT(numNewSlots > 0);
LiveRegisterSet save = liveVolatileRegs();
masm.PushRegsInMask(save);
using Fn = bool (*)(JSContext* cx, NativeObject* obj, uint32_t newCount);
masm.setupUnalignedABICall(scratch1);
masm.loadJSContext(scratch1);
masm.passABIArg(scratch1);
masm.passABIArg(obj);
masm.move32(Imm32(numNewSlots), scratch2.ref());
masm.passABIArg(scratch2.ref());
masm.callWithABI<Fn, NativeObject::growSlotsPure>();
masm.storeCallPointerResult(scratch1);
LiveRegisterSet ignore;
ignore.add(scratch1);
masm.PopRegsInMaskIgnore(save, ignore);
masm.branchIfFalseBool(scratch1, failure->label());
}
// Update the object's shape.
masm.storeObjShape(newShape, obj,
[](MacroAssembler& masm, const Address& addr) {
EmitPreBarrier(masm, addr, MIRType::Shape);
});
// Perform the store. No pre-barrier required since this is a new
// initialization.
if (op == CacheOp::AddAndStoreFixedSlot) {
Address slot(obj, offset);
masm.storeConstantOrRegister(val, slot);
} else {
MOZ_ASSERT(op == CacheOp::AddAndStoreDynamicSlot ||
op == CacheOp::AllocateAndStoreDynamicSlot);
masm.loadPtr(Address(obj, NativeObject::offsetOfSlots()), scratch1);
Address slot(scratch1, offset);
masm.storeConstantOrRegister(val, slot);
}
emitPostBarrierSlot(obj, val, scratch1);
return true;
}
bool IonCacheIRCompiler::emitAddAndStoreFixedSlot(ObjOperandId objId,
uint32_t offsetOffset,
ValOperandId rhsId,
uint32_t newShapeOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Maybe<uint32_t> numNewSlotsOffset = mozilla::Nothing();
return emitAddAndStoreSlotShared(CacheOp::AddAndStoreFixedSlot, objId,
offsetOffset, rhsId, newShapeOffset,
numNewSlotsOffset);
}
bool IonCacheIRCompiler::emitAddAndStoreDynamicSlot(ObjOperandId objId,
uint32_t offsetOffset,
ValOperandId rhsId,
uint32_t newShapeOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
Maybe<uint32_t> numNewSlotsOffset = mozilla::Nothing();
return emitAddAndStoreSlotShared(CacheOp::AddAndStoreDynamicSlot, objId,
offsetOffset, rhsId, newShapeOffset,
numNewSlotsOffset);
}
bool IonCacheIRCompiler::emitAllocateAndStoreDynamicSlot(
ObjOperandId objId, uint32_t offsetOffset, ValOperandId rhsId,
uint32_t newShapeOffset, uint32_t numNewSlotsOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
return emitAddAndStoreSlotShared(CacheOp::AllocateAndStoreDynamicSlot, objId,
offsetOffset, rhsId, newShapeOffset,
mozilla::Some(numNewSlotsOffset));
}
bool IonCacheIRCompiler::emitLoadStringCharResult(StringOperandId strId,
Int32OperandId indexId,
bool handleOOB) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoOutputRegister output(*this);
Register str = allocator.useRegister(masm, strId);
Register index = allocator.useRegister(masm, indexId);
AutoScratchRegisterMaybeOutput scratch1(allocator, masm, output);
AutoScratchRegisterMaybeOutputType scratch2(allocator, masm, output);
AutoScratchRegister scratch3(allocator, masm);
FailurePath* failure;
if (!addFailurePath(&failure)) {
return false;
}
// Bounds check, load string char.
Label done;
Label loadFailed;
if (!handleOOB) {
masm.spectreBoundsCheck32(index, Address(str, JSString::offsetOfLength()),
scratch1, failure->label());
masm.loadStringChar(str, index, scratch1, scratch2, scratch3,
failure->label());
} else {
// Return the empty string for out-of-bounds access.
masm.movePtr(ImmGCPtr(cx_->runtime()->emptyString), scratch2);
// This CacheIR op is always preceded by |LinearizeForCharAccess|, so we're
// guaranteed to see no nested ropes.
masm.spectreBoundsCheck32(index, Address(str, JSString::offsetOfLength()),
scratch1, &done);
masm.loadStringChar(str, index, scratch1, scratch2, scratch3, &loadFailed);
}
// Load StaticString for this char. For larger code units perform a VM call.
Label vmCall;
masm.lookupStaticString(scratch1, scratch2, cx_->staticStrings(), &vmCall);
masm.jump(&done);
if (handleOOB) {
masm.bind(&loadFailed);
masm.assumeUnreachable("loadStringChar can't fail for linear strings");
}
{
masm.bind(&vmCall);
// FailurePath and AutoSaveLiveRegisters don't get along very well. Both are
// modifying the stack and expect that no other stack manipulations are
// made. Therefore we need to use an ABI call instead of a VM call here.
LiveRegisterSet volatileRegs = liveVolatileRegs();
volatileRegs.takeUnchecked(scratch1);
volatileRegs.takeUnchecked(scratch2);
volatileRegs.takeUnchecked(scratch3);
volatileRegs.takeUnchecked(output);
masm.PushRegsInMask(volatileRegs);
using Fn = JSLinearString* (*)(JSContext* cx, int32_t code);
masm.setupUnalignedABICall(scratch2);
masm.loadJSContext(scratch2);
masm.passABIArg(scratch2);
masm.passABIArg(scratch1);
masm.callWithABI<Fn, jit::StringFromCharCodeNoGC>();
masm.storeCallPointerResult(scratch2);
masm.PopRegsInMask(volatileRegs);
masm.branchPtr(Assembler::Equal, scratch2, ImmWord(0), failure->label());
}
masm.bind(&done);
masm.tagValue(JSVAL_TYPE_STRING, scratch2, output.valueReg());
return true;
}
bool IonCacheIRCompiler::emitCallNativeSetter(ObjOperandId receiverId,
uint32_t setterOffset,
ValOperandId rhsId,
bool sameRealm,
uint32_t nargsAndFlagsOffset) {
JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
AutoSaveLiveRegisters save(*this);
Register receiver = allocator.useRegister(masm, receiverId);
JSFunction* target = &objectStubField(setterOffset)->as<JSFunction>();
MOZ_ASSERT(target->isNativeFun());
ConstantOrRegister val = allocator.useConstantOrRegister(masm, rhsId);
AutoScratchRegister argJSContext(allocator, masm);
AutoScratchRegister argVp(allocator, masm);
AutoScratchRegister argUintN(allocator, masm);
#ifndef JS_CODEGEN_X86
AutoScratchRegister scratch(allocator, masm);
#else
// Not enough registers on x86.
Register scratch = argUintN;
#endif
allocator.discardStack(masm);
// Set up the call:
// bool (*)(JSContext*, unsigned, Value* vp)
// vp[0] is callee/outparam
// vp[1] is |this|
// vp[2] is the value
// Build vp and move the base into argVpReg.
masm.Push(val);
masm.Push(TypedOrValueRegister(MIRType::Object, AnyRegister(receiver)));
masm.Push(ObjectValue(*target));
masm.moveStackPtrTo(argVp.get());
// Preload other regs.
masm.loadJSContext(argJSContext);
masm.move32(Imm32(1), argUintN);
// Push marking data for later use.