/*

* Copyright (C) 2009-2021 Apple Inc. All rights reserved.

* Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

*

* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR

* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#include "config.h"

#if ENABLE(JIT)

#include "JIT.h"

#include "BasicBlockLocation.h"

#include "BytecodeGenerator.h"

#include "Exception.h"

#include "JITInlines.h"

#include "JITThunks.h"

#include "JSCast.h"

#include "JSFunction.h"

#include "JSPropertyNameEnumerator.h"

#include "LinkBuffer.h"

#include "SuperSampler.h"

#include "ThunkGenerators.h"

#include "TypeLocation.h"

#include "TypeProfilerLog.h"

#include "VirtualRegister.h"

namespace JSC {

#if USE(JSVALUE64)

void JIT::emit_op_mov(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpMov>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister src = bytecode.m_src;

if (src.isConstant()) {

JSValue value = m_codeBlock->getConstant(src);

if (!value.isNumber())

store64(TrustedImm64(JSValue::encode(value)), addressFor(dst));

else

store64(Imm64(JSValue::encode(value)), addressFor(dst));

return;

}

load64(addressFor(src), regT0);

store64(regT0, addressFor(dst));

}

void JIT::emit_op_end(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpEnd>();

RELEASE_ASSERT(returnValueGPR != callFrameRegister);

emitGetVirtualRegister(bytecode.m_value, returnValueGPR);

emitRestoreCalleeSaves();

emitFunctionEpilogue();

ret();

}

void JIT::emit_op_jmp(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJmp>();

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

addJump(jump(), target);

}

void JIT::emit_op_new_object(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpNewObject>();

auto& metadata = bytecode.metadata(m_codeBlock);

Structure* structure = metadata.m_objectAllocationProfile.structure();

size_t allocationSize = JSFinalObject::allocationSize(structure->inlineCapacity());

Allocator allocator = allocatorForNonVirtualConcurrently<JSFinalObject>(*m_vm, allocationSize, AllocatorForMode::AllocatorIfExists);

RegisterID resultReg = regT0;

RegisterID allocatorReg = regT1;

RegisterID scratchReg = regT2;

if (!allocator)

addSlowCase(jump());

else {

JumpList slowCases;

auto butterfly = TrustedImmPtr(nullptr);

emitAllocateJSObject(resultReg, JITAllocator::constant(allocator), allocatorReg, TrustedImmPtr(structure), butterfly, scratchReg, slowCases);

emitInitializeInlineStorage(resultReg, structure->inlineCapacity());

mutatorFence(*m_vm);

addSlowCase(slowCases);

emitPutVirtualRegister(bytecode.m_dst);

}

}

void JIT::emitSlow_op_new_object(const Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

linkAllSlowCases(iter);

auto bytecode = currentInstruction->as<OpNewObject>();

auto& metadata = bytecode.metadata(m_codeBlock);

VirtualRegister dst = bytecode.m_dst;

Structure* structure = metadata.m_objectAllocationProfile.structure();

callOperationNoExceptionCheck(operationNewObject, &vm(), structure);

emitStoreCell(dst, returnValueGPR);

}

void JIT::emit_op_overrides_has_instance(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpOverridesHasInstance>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister constructor = bytecode.m_constructor;

VirtualRegister hasInstanceValue = bytecode.m_hasInstanceValue;

emitGetVirtualRegister(hasInstanceValue, regT0);

// We don't jump if we know what Symbol.hasInstance would do.

Jump customhasInstanceValue = branchPtr(NotEqual, regT0, TrustedImmPtr(m_codeBlock->globalObject()->functionProtoHasInstanceSymbolFunction()));

emitGetVirtualRegister(constructor, regT0);

// Check that constructor 'ImplementsDefaultHasInstance' i.e. the object is not a C-API user nor a bound function.

test8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(ImplementsDefaultHasInstance), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

Jump done = jump();

customhasInstanceValue.link(this);

move(TrustedImm32(JSValue::ValueTrue), regT0);

done.link(this);

emitPutVirtualRegister(dst);

}

void JIT::emit_op_instanceof(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpInstanceof>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_value;

VirtualRegister proto = bytecode.m_prototype;

// Load the operands (baseVal, proto, and value respectively) into registers.

// We use regT0 for baseVal since we will be done with this first, and we can then use it for the result.

emitGetVirtualRegister(value, regT2);

emitGetVirtualRegister(proto, regT1);

// Check that proto are cells. baseVal must be a cell - this is checked by the get_by_id for Symbol.hasInstance.

emitJumpSlowCaseIfNotJSCell(regT2, value);

emitJumpSlowCaseIfNotJSCell(regT1, proto);

JITInstanceOfGenerator gen(

m_codeBlock, JITType::BaselineJIT, CodeOrigin(m_bytecodeIndex), CallSiteIndex(m_bytecodeIndex),

RegisterSet::stubUnavailableRegisters(),

regT0, // result

regT2, // value

regT1, // proto

regT5,

regT3, regT4); // scratch

gen.generateFastPath(*this);

if (!JITCode::useDataIC(JITType::BaselineJIT))

addSlowCase(gen.slowPathJump());

else

addSlowCase();

m_instanceOfs.append(gen);

emitPutVirtualRegister(dst);

}

void JIT::emitSlow_op_instanceof(const Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

linkAllSlowCases(iter);

auto bytecode = currentInstruction->as<OpInstanceof>();

VirtualRegister resultVReg = bytecode.m_dst;

JITInstanceOfGenerator& gen = m_instanceOfs[m_instanceOfIndex++];

Label coldPathBegin = label();

Call call;

if (JITCode::useDataIC(JITType::BaselineJIT)) {

gen.stubInfo()->m_slowOperation = operationInstanceOfOptimize;

move(TrustedImmPtr(gen.stubInfo()), GPRInfo::nonArgGPR0);

callOperation<decltype(operationInstanceOfOptimize)>(Address(GPRInfo::nonArgGPR0, StructureStubInfo::offsetOfSlowOperation()), resultVReg, TrustedImmPtr(m_codeBlock->globalObject()), GPRInfo::nonArgGPR0, regT2, regT1);

} else

call = callOperation(operationInstanceOfOptimize, resultVReg, TrustedImmPtr(m_codeBlock->globalObject()), gen.stubInfo(), regT2, regT1);

gen.reportSlowPathCall(coldPathBegin, call);

}

void JIT::emit_op_instanceof_custom(const Instruction*)

{

// This always goes to slow path since we expect it to be rare.

addSlowCase(jump());

}

void JIT::emit_op_is_empty(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpIsEmpty>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

emitGetVirtualRegister(value, regT0);

compare64(Equal, regT0, TrustedImm32(JSValue::encode(JSValue())), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(dst);

}

void JIT::emit_op_typeof_is_undefined(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpTypeofIsUndefined>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

emitGetVirtualRegister(value, regT0);

Jump isCell = branchIfCell(regT0);

compare64(Equal, regT0, TrustedImm32(JSValue::ValueUndefined), regT0);

Jump done = jump();

isCell.link(this);

Jump isMasqueradesAsUndefined = branchTest8(NonZero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));

move(TrustedImm32(0), regT0);

Jump notMasqueradesAsUndefined = jump();

isMasqueradesAsUndefined.link(this);

emitLoadStructure(vm(), regT0, regT1, regT2);

move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);

loadPtr(Address(regT1, Structure::globalObjectOffset()), regT1);

comparePtr(Equal, regT0, regT1, regT0);

notMasqueradesAsUndefined.link(this);

done.link(this);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(dst);

}

void JIT::emit_op_is_undefined_or_null(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpIsUndefinedOrNull>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

emitGetVirtualRegister(value, regT0);

and64(TrustedImm32(~JSValue::UndefinedTag), regT0);

compare64(Equal, regT0, TrustedImm32(JSValue::ValueNull), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(dst);

}

void JIT::emit_op_is_boolean(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpIsBoolean>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

emitGetVirtualRegister(value, regT0);

xor64(TrustedImm32(JSValue::ValueFalse), regT0);

test64(Zero, regT0, TrustedImm32(static_cast<int32_t>(~1)), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(dst);

}

void JIT::emit_op_is_number(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpIsNumber>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

emitGetVirtualRegister(value, regT0);

test64(NonZero, regT0, numberTagRegister, regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(dst);

}

#if USE(BIGINT32)

void JIT::emit_op_is_big_int(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpIsBigInt>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

emitGetVirtualRegister(value, regT0);

Jump isCell = branchIfCell(regT0);

move(TrustedImm64(JSValue::BigInt32Mask), regT1);

and64(regT1, regT0);

compare64(Equal, regT0, TrustedImm32(JSValue::BigInt32Tag), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

Jump done = jump();

isCell.link(this);

compare8(Equal, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(HeapBigIntType), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

done.link(this);

emitPutVirtualRegister(dst);

}

#else // if !USE(BIGINT32)

NO_RETURN void JIT::emit_op_is_big_int(const Instruction*)

{

// If we only have HeapBigInts, then we emit isCellWithType instead of isBigInt.

RELEASE_ASSERT_NOT_REACHED();

}

#endif

void JIT::emit_op_is_cell_with_type(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpIsCellWithType>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

int type = bytecode.m_type;

emitGetVirtualRegister(value, regT0);

Jump isNotCell = branchIfNotCell(regT0);

compare8(Equal, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(type), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

Jump done = jump();

isNotCell.link(this);

move(TrustedImm32(JSValue::ValueFalse), regT0);

done.link(this);

emitPutVirtualRegister(dst);

}

void JIT::emit_op_is_object(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpIsObject>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister value = bytecode.m_operand;

emitGetVirtualRegister(value, regT0);

Jump isNotCell = branchIfNotCell(regT0);

compare8(AboveOrEqual, Address(regT0, JSCell::typeInfoTypeOffset()), TrustedImm32(ObjectType), regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

Jump done = jump();

isNotCell.link(this);

move(TrustedImm32(JSValue::ValueFalse), regT0);

done.link(this);

emitPutVirtualRegister(dst);

}

void JIT::emit_op_ret(const Instruction* currentInstruction)

{

ASSERT(callFrameRegister != regT1);

ASSERT(regT1 != returnValueGPR);

ASSERT(returnValueGPR != callFrameRegister);

// Return the result in %eax.

auto bytecode = currentInstruction->as<OpRet>();

emitGetVirtualRegister(bytecode.m_value, returnValueGPR);

#if !ENABLE(EXTRA_CTI_THUNKS)

checkStackPointerAlignment();

emitRestoreCalleeSaves();

emitFunctionEpilogue();

ret();

#else

emitNakedNearJump(vm().getCTIStub(op_ret_handlerGenerator).code());

#endif

}

#if ENABLE(EXTRA_CTI_THUNKS)

MacroAssemblerCodeRef<JITThunkPtrTag> JIT::op_ret_handlerGenerator(VM& vm)

{

JIT jit(vm);

jit.checkStackPointerAlignment();

jit.emitRestoreCalleeSavesFor(&RegisterAtOffsetList::llintBaselineCalleeSaveRegisters());

jit.emitFunctionEpilogue();

jit.ret();

LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID, LinkBuffer::Profile::ExtraCTIThunk);

return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "Baseline: op_ret_handler");

}

#endif // ENABLE(EXTRA_CTI_THUNKS)

void JIT::emit_op_to_primitive(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpToPrimitive>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister src = bytecode.m_src;

emitGetVirtualRegister(src, regT0);

Jump isImm = branchIfNotCell(regT0);

addSlowCase(branchIfObject(regT0));

isImm.link(this);

if (dst != src)

emitPutVirtualRegister(dst);

}

void JIT::emit_op_to_property_key(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpToPropertyKey>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister src = bytecode.m_src;

emitGetVirtualRegister(src, regT0);

addSlowCase(branchIfNotCell(regT0));

Jump done = branchIfSymbol(regT0);

addSlowCase(branchIfNotString(regT0));

done.link(this);

if (src != dst)

emitPutVirtualRegister(dst);

}

void JIT::emit_op_set_function_name(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpSetFunctionName>();

emitGetVirtualRegister(bytecode.m_function, regT0);

emitGetVirtualRegister(bytecode.m_name, regT1);

callOperation(operationSetFunctionName, TrustedImmPtr(m_codeBlock->globalObject()), regT0, regT1);

}

void JIT::emit_op_not(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpNot>();

emitGetVirtualRegister(bytecode.m_operand, regT0);

// Invert against JSValue(false); if the value was tagged as a boolean, then all bits will be

// clear other than the low bit (which will be 0 or 1 for false or true inputs respectively).

// Then invert against JSValue(true), which will add the tag back in, and flip the low bit.

xor64(TrustedImm32(JSValue::ValueFalse), regT0);

addSlowCase(branchTestPtr(NonZero, regT0, TrustedImm32(static_cast<int32_t>(~1))));

xor64(TrustedImm32(JSValue::ValueTrue), regT0);

emitPutVirtualRegister(bytecode.m_dst);

}

void JIT::emit_op_jfalse(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJfalse>();

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

constexpr GPRReg value = regT0;

emitGetVirtualRegister(bytecode.m_condition, value);

#if !ENABLE(EXTRA_CTI_THUNKS)

constexpr GPRReg scratch1 = regT1;

constexpr GPRReg scratch2 = regT2;

constexpr bool shouldCheckMasqueradesAsUndefined = true;

addJump(branchIfFalsey(vm(), JSValueRegs(value), scratch1, scratch2, fpRegT0, fpRegT1, shouldCheckMasqueradesAsUndefined, m_codeBlock->globalObject()), target);

#else

emitNakedNearCall(vm().getCTIStub(valueIsFalseyGenerator).retaggedCode<NoPtrTag>());

addJump(branchTest32(NonZero, regT0), target);

#endif

}

#if ENABLE(EXTRA_CTI_THUNKS)

MacroAssemblerCodeRef<JITThunkPtrTag> JIT::valueIsFalseyGenerator(VM& vm)

{

// The thunk generated by this function can only work with the LLInt / Baseline JIT because

// it makes assumptions about the right globalObject being available from CallFrame::codeBlock().

// DFG/FTL may inline functions belonging to other globalObjects, which may not match

// CallFrame::codeBlock().

JIT jit(vm);

constexpr GPRReg value = regT0;

constexpr GPRReg scratch1 = regT1;

constexpr GPRReg scratch2 = regT2;

constexpr bool shouldCheckMasqueradesAsUndefined = true;

jit.tagReturnAddress();

constexpr GPRReg globalObjectGPR = regT3;

jit.loadPtr(addressFor(CallFrameSlot::codeBlock), globalObjectGPR);

jit.loadPtr(Address(globalObjectGPR, CodeBlock::offsetOfGlobalObject()), globalObjectGPR);

auto isFalsey = jit.branchIfFalsey(vm, JSValueRegs(value), scratch1, scratch2, fpRegT0, fpRegT1, shouldCheckMasqueradesAsUndefined, globalObjectGPR);

jit.move(TrustedImm32(0), regT0);

Jump done = jit.jump();

isFalsey.link(&jit);

jit.move(TrustedImm32(1), regT0);

done.link(&jit);

jit.ret();

LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID, LinkBuffer::Profile::Thunk);

return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "Baseline: valueIsfalsey");

}

#endif // ENABLE(EXTRA_CTI_THUNKS)

void JIT::emit_op_jeq_null(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJeqNull>();

VirtualRegister src = bytecode.m_value;

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

emitGetVirtualRegister(src, regT0);

Jump isImmediate = branchIfNotCell(regT0);

// First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.

Jump isNotMasqueradesAsUndefined = branchTest8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined));

emitLoadStructure(vm(), regT0, regT2, regT1);

move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);

addJump(branchPtr(Equal, Address(regT2, Structure::globalObjectOffset()), regT0), target);

Jump masqueradesGlobalObjectIsForeign = jump();

// Now handle the immediate cases - undefined & null

isImmediate.link(this);

and64(TrustedImm32(~JSValue::UndefinedTag), regT0);

addJump(branch64(Equal, regT0, TrustedImm64(JSValue::encode(jsNull()))), target);

isNotMasqueradesAsUndefined.link(this);

masqueradesGlobalObjectIsForeign.link(this);

};

void JIT::emit_op_jneq_null(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJneqNull>();

VirtualRegister src = bytecode.m_value;

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

emitGetVirtualRegister(src, regT0);

Jump isImmediate = branchIfNotCell(regT0);

// First, handle JSCell cases - check MasqueradesAsUndefined bit on the structure.

addJump(branchTest8(Zero, Address(regT0, JSCell::typeInfoFlagsOffset()), TrustedImm32(MasqueradesAsUndefined)), target);

emitLoadStructure(vm(), regT0, regT2, regT1);

move(TrustedImmPtr(m_codeBlock->globalObject()), regT0);

addJump(branchPtr(NotEqual, Address(regT2, Structure::globalObjectOffset()), regT0), target);

Jump wasNotImmediate = jump();

// Now handle the immediate cases - undefined & null

isImmediate.link(this);

and64(TrustedImm32(~JSValue::UndefinedTag), regT0);

addJump(branch64(NotEqual, regT0, TrustedImm64(JSValue::encode(jsNull()))), target);

wasNotImmediate.link(this);

}

void JIT::emit_op_jundefined_or_null(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJundefinedOrNull>();

VirtualRegister value = bytecode.m_value;

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

emitGetVirtualRegister(value, regT0);

and64(TrustedImm32(~JSValue::UndefinedTag), regT0);

addJump(branch64(Equal, regT0, TrustedImm64(JSValue::encode(jsNull()))), target);

}

void JIT::emit_op_jnundefined_or_null(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJnundefinedOrNull>();

VirtualRegister value = bytecode.m_value;

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

emitGetVirtualRegister(value, regT0);

and64(TrustedImm32(~JSValue::UndefinedTag), regT0);

addJump(branch64(NotEqual, regT0, TrustedImm64(JSValue::encode(jsNull()))), target);

}

void JIT::emit_op_jneq_ptr(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJneqPtr>();

auto& metadata = bytecode.metadata(m_codeBlock);

VirtualRegister src = bytecode.m_value;

JSValue specialPointer = getConstantOperand(bytecode.m_specialPointer);

ASSERT(specialPointer.isCell());

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

emitGetVirtualRegister(src, regT0);

CCallHelpers::Jump equal = branchPtr(Equal, regT0, TrustedImmPtr(specialPointer.asCell()));

store8(TrustedImm32(1), &metadata.m_hasJumped);

addJump(jump(), target);

equal.link(this);

}

void JIT::emit_op_eq(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpEq>();

emitGetVirtualRegisters(bytecode.m_lhs, regT0, bytecode.m_rhs, regT1);

emitJumpSlowCaseIfNotInt(regT0, regT1, regT2);

compare32(Equal, regT1, regT0, regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(bytecode.m_dst);

}

void JIT::emit_op_jeq(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJeq>();

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

emitGetVirtualRegisters(bytecode.m_lhs, regT0, bytecode.m_rhs, regT1);

emitJumpSlowCaseIfNotInt(regT0, regT1, regT2);

addJump(branch32(Equal, regT0, regT1), target);

}

void JIT::emit_op_jtrue(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJtrue>();

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

constexpr GPRReg value = regT0;

emitGetVirtualRegister(bytecode.m_condition, value);

#if !ENABLE(EXTRA_CTI_THUNKS)

constexpr GPRReg scratch1 = regT1;

constexpr GPRReg scratch2 = regT2;

constexpr bool shouldCheckMasqueradesAsUndefined = true;

addJump(branchIfTruthy(vm(), JSValueRegs(value), scratch1, scratch2, fpRegT0, fpRegT1, shouldCheckMasqueradesAsUndefined, m_codeBlock->globalObject()), target);

#else

emitNakedNearCall(vm().getCTIStub(valueIsTruthyGenerator).retaggedCode<NoPtrTag>());

addJump(branchTest32(NonZero, regT0), target);

#endif

}

#if ENABLE(EXTRA_CTI_THUNKS)

MacroAssemblerCodeRef<JITThunkPtrTag> JIT::valueIsTruthyGenerator(VM& vm)

{

// The thunk generated by this function can only work with the LLInt / Baseline JIT because

// it makes assumptions about the right globalObject being available from CallFrame::codeBlock().

// DFG/FTL may inline functions belonging to other globalObjects, which may not match

// CallFrame::codeBlock().

JIT jit(vm);

constexpr GPRReg value = regT0;

constexpr GPRReg scratch1 = regT1;

constexpr GPRReg scratch2 = regT2;

constexpr bool shouldCheckMasqueradesAsUndefined = true;

jit.tagReturnAddress();

constexpr GPRReg globalObjectGPR = regT3;

jit.loadPtr(addressFor(CallFrameSlot::codeBlock), globalObjectGPR);

jit.loadPtr(Address(globalObjectGPR, CodeBlock::offsetOfGlobalObject()), globalObjectGPR);

auto isTruthy = jit.branchIfTruthy(vm, JSValueRegs(value), scratch1, scratch2, fpRegT0, fpRegT1, shouldCheckMasqueradesAsUndefined, globalObjectGPR);

jit.move(TrustedImm32(0), regT0);

Jump done = jit.jump();

isTruthy.link(&jit);

jit.move(TrustedImm32(1), regT0);

done.link(&jit);

jit.ret();

LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID, LinkBuffer::Profile::Thunk);

return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "Baseline: valueIsfalsey");

}

#endif // ENABLE(EXTRA_CTI_THUNKS)

void JIT::emit_op_neq(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpNeq>();

emitGetVirtualRegisters(bytecode.m_lhs, regT0, bytecode.m_rhs, regT1);

emitJumpSlowCaseIfNotInt(regT0, regT1, regT2);

compare32(NotEqual, regT1, regT0, regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(bytecode.m_dst);

}

void JIT::emit_op_jneq(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpJneq>();

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

emitGetVirtualRegisters(bytecode.m_lhs, regT0, bytecode.m_rhs, regT1);

emitJumpSlowCaseIfNotInt(regT0, regT1, regT2);

addJump(branch32(NotEqual, regT0, regT1), target);

}

void JIT::emit_op_throw(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpThrow>();

ASSERT(regT0 == returnValueGPR);

#if !ENABLE(EXTRA_CTI_THUNKS)

copyCalleeSavesToEntryFrameCalleeSavesBuffer(vm().topEntryFrame);

emitGetVirtualRegister(bytecode.m_value, regT0);

callOperationNoExceptionCheck(operationThrow, TrustedImmPtr(m_codeBlock->globalObject()), regT0);

jumpToExceptionHandler(vm());

#else

constexpr GPRReg bytecodeOffsetGPR = argumentGPR2;

constexpr GPRReg thrownValueGPR = argumentGPR1;

uint32_t bytecodeOffset = m_bytecodeIndex.offset();

move(TrustedImm32(bytecodeOffset), bytecodeOffsetGPR);

emitGetVirtualRegister(bytecode.m_value, thrownValueGPR);

emitNakedNearJump(vm().getCTIStub(op_throw_handlerGenerator).code());

#endif // ENABLE(EXTRA_CTI_THUNKS)

}

#if ENABLE(EXTRA_CTI_THUNKS)

MacroAssemblerCodeRef<JITThunkPtrTag> JIT::op_throw_handlerGenerator(VM& vm)

{

JIT jit(vm);

constexpr GPRReg bytecodeOffsetGPR = argumentGPR2;

constexpr GPRReg thrownValueGPR = argumentGPR1;

jit.store32(bytecodeOffsetGPR, tagFor(CallFrameSlot::argumentCountIncludingThis));

#if NUMBER_OF_CALLEE_SAVES_REGISTERS > 0

jit.loadPtr(&vm.topEntryFrame, argumentGPR0);

jit.copyCalleeSavesToEntryFrameCalleeSavesBufferImpl(argumentGPR0);

#endif

constexpr GPRReg globalObjectGPR = argumentGPR0;

jit.loadPtr(addressFor(CallFrameSlot::codeBlock), globalObjectGPR);

jit.loadPtr(Address(globalObjectGPR, CodeBlock::offsetOfGlobalObject()), globalObjectGPR);

jit.setupArguments<decltype(operationThrow)>(globalObjectGPR, thrownValueGPR);

jit.prepareCallOperation(vm);

Call operation = jit.call(OperationPtrTag);

jit.jumpToExceptionHandler(vm);

LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID, LinkBuffer::Profile::ExtraCTIThunk);

patchBuffer.link(operation, FunctionPtr<OperationPtrTag>(operationThrow));

return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "Baseline: op_throw_handler");

}

#endif // ENABLE(EXTRA_CTI_THUNKS)

template<typename Op>

void JIT::compileOpStrictEq(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<Op>();

VirtualRegister dst = bytecode.m_dst;

VirtualRegister src1 = bytecode.m_lhs;

VirtualRegister src2 = bytecode.m_rhs;

emitGetVirtualRegisters(src1, regT0, src2, regT1);

#if USE(BIGINT32)

/* At a high level we do (assuming 'type' to be StrictEq):

If (left is Double || right is Double)

goto slowPath;

result = (left == right);

if (result)

goto done;

if (left is Cell || right is Cell)

goto slowPath;

done:

return result;

*/

// This fragment implements (left is Double || right is Double), with a single branch instead of the 4 that would be naively required if we used branchIfInt32/branchIfNumber

// The trick is that if a JSValue is an Int32, then adding 1<<49 to it will make it overflow, leaving all high bits at 0

// If it is not a number at all, then 1<<49 will be its only high bit set

// Leaving only doubles above or equal 1<<50.

move(regT0, regT2);

move(regT1, regT3);

move(TrustedImm64(JSValue::LowestOfHighBits), regT5);

add64(regT5, regT2);

add64(regT5, regT3);

lshift64(TrustedImm32(1), regT5);

or64(regT2, regT3);

addSlowCase(branch64(AboveOrEqual, regT3, regT5));

compare64(Equal, regT0, regT1, regT5);

Jump done = branchTest64(NonZero, regT5);

move(regT0, regT2);

// Jump slow if at least one is a cell (to cover strings and BigInts).

and64(regT1, regT2);

// FIXME: we could do something more precise: unless there is a BigInt32, we only need to do the slow path if both are strings

addSlowCase(branchIfCell(regT2));

done.link(this);

if constexpr (std::is_same<Op, OpNstricteq>::value)

xor64(TrustedImm64(1), regT5);

boxBoolean(regT5, JSValueRegs { regT5 });

emitPutVirtualRegister(dst, regT5);

#else // if !USE(BIGINT32)

// Jump slow if both are cells (to cover strings).

move(regT0, regT2);

or64(regT1, regT2);

addSlowCase(branchIfCell(regT2));

// Jump slow if either is a double. First test if it's an integer, which is fine, and then test

// if it's a double.

Jump leftOK = branchIfInt32(regT0);

addSlowCase(branchIfNumber(regT0));

leftOK.link(this);

Jump rightOK = branchIfInt32(regT1);

addSlowCase(branchIfNumber(regT1));

rightOK.link(this);

if constexpr (std::is_same<Op, OpStricteq>::value)

compare64(Equal, regT1, regT0, regT0);

else

compare64(NotEqual, regT1, regT0, regT0);

boxBoolean(regT0, JSValueRegs { regT0 });

emitPutVirtualRegister(dst);

#endif

}

void JIT::emit_op_stricteq(const Instruction* currentInstruction)

{

compileOpStrictEq<OpStricteq>(currentInstruction);

}

void JIT::emit_op_nstricteq(const Instruction* currentInstruction)

{

compileOpStrictEq<OpNstricteq>(currentInstruction);

}

template<typename Op>

void JIT::compileOpStrictEqJump(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<Op>();

int target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

VirtualRegister src1 = bytecode.m_lhs;

VirtualRegister src2 = bytecode.m_rhs;

emitGetVirtualRegisters(src1, regT0, src2, regT1);

#if USE(BIGINT32)

/* At a high level we do (assuming 'type' to be StrictEq):

If (left is Double || right is Double)

goto slowPath;

if (left == right)

goto taken;

if (left is Cell || right is Cell)

goto slowPath;

goto notTaken;

*/

// This fragment implements (left is Double || right is Double), with a single branch instead of the 4 that would be naively required if we used branchIfInt32/branchIfNumber

// The trick is that if a JSValue is an Int32, then adding 1<<49 to it will make it overflow, leaving all high bits at 0

// If it is not a number at all, then 1<<49 will be its only high bit set

// Leaving only doubles above or equal 1<<50.

move(regT0, regT2);

move(regT1, regT3);

move(TrustedImm64(JSValue::LowestOfHighBits), regT5);

add64(regT5, regT2);

add64(regT5, regT3);

lshift64(TrustedImm32(1), regT5);

or64(regT2, regT3);

addSlowCase(branch64(AboveOrEqual, regT3, regT5));

Jump areEqual = branch64(Equal, regT0, regT1);

if constexpr (std::is_same<Op, OpJstricteq>::value)

addJump(areEqual, target);

move(regT0, regT2);

// Jump slow if at least one is a cell (to cover strings and BigInts).

and64(regT1, regT2);

// FIXME: we could do something more precise: unless there is a BigInt32, we only need to do the slow path if both are strings

addSlowCase(branchIfCell(regT2));

if constexpr (std::is_same<Op, OpJnstricteq>::value) {

addJump(jump(), target);

areEqual.link(this);

}

#else // if !USE(BIGINT32)

// Jump slow if both are cells (to cover strings).

move(regT0, regT2);

or64(regT1, regT2);

addSlowCase(branchIfCell(regT2));

// Jump slow if either is a double. First test if it's an integer, which is fine, and then test

// if it's a double.

Jump leftOK = branchIfInt32(regT0);

addSlowCase(branchIfNumber(regT0));

leftOK.link(this);

Jump rightOK = branchIfInt32(regT1);

addSlowCase(branchIfNumber(regT1));

rightOK.link(this);

if constexpr (std::is_same<Op, OpJstricteq>::value)

addJump(branch64(Equal, regT1, regT0), target);

else

addJump(branch64(NotEqual, regT1, regT0), target);

#endif

}

void JIT::emit_op_jstricteq(const Instruction* currentInstruction)

{

compileOpStrictEqJump<OpJstricteq>(currentInstruction);

}

void JIT::emit_op_jnstricteq(const Instruction* currentInstruction)

{

compileOpStrictEqJump<OpJnstricteq>(currentInstruction);

}

void JIT::emitSlow_op_jstricteq(const Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

linkAllSlowCases(iter);

auto bytecode = currentInstruction->as<OpJstricteq>();

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

callOperation(operationCompareStrictEq, TrustedImmPtr(m_codeBlock->globalObject()), regT0, regT1);

emitJumpSlowToHot(branchTest32(NonZero, returnValueGPR), target);

}

void JIT::emitSlow_op_jnstricteq(const Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)

{

linkAllSlowCases(iter);

auto bytecode = currentInstruction->as<OpJnstricteq>();

unsigned target = jumpTarget(currentInstruction, bytecode.m_targetLabel);

callOperation(operationCompareStrictEq, TrustedImmPtr(m_codeBlock->globalObject()), regT0, regT1);

emitJumpSlowToHot(branchTest32(Zero, returnValueGPR), target);

}

void JIT::emit_op_to_number(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpToNumber>();

VirtualRegister dstVReg = bytecode.m_dst;

VirtualRegister srcVReg = bytecode.m_operand;

emitGetVirtualRegister(srcVReg, regT0);

addSlowCase(branchIfNotNumber(regT0));

emitValueProfilingSite(bytecode.metadata(m_codeBlock), regT0);

if (srcVReg != dstVReg)

emitPutVirtualRegister(dstVReg);

}

void JIT::emit_op_to_numeric(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpToNumeric>();

VirtualRegister dstVReg = bytecode.m_dst;

VirtualRegister srcVReg = bytecode.m_operand;

emitGetVirtualRegister(srcVReg, regT0);

Jump isNotCell = branchIfNotCell(regT0);

addSlowCase(branchIfNotHeapBigInt(regT0));

Jump isBigInt = jump();

isNotCell.link(this);

addSlowCase(branchIfNotNumber(regT0));

isBigInt.link(this);

emitValueProfilingSite(bytecode.metadata(m_codeBlock), regT0);

if (srcVReg != dstVReg)

emitPutVirtualRegister(dstVReg);

}

void JIT::emit_op_to_string(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpToString>();

VirtualRegister srcVReg = bytecode.m_operand;

emitGetVirtualRegister(srcVReg, regT0);

addSlowCase(branchIfNotCell(regT0));

addSlowCase(branchIfNotString(regT0));

emitPutVirtualRegister(bytecode.m_dst);

}

void JIT::emit_op_to_object(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpToObject>();

VirtualRegister dstVReg = bytecode.m_dst;

VirtualRegister srcVReg = bytecode.m_operand;

emitGetVirtualRegister(srcVReg, regT0);

addSlowCase(branchIfNotCell(regT0));

addSlowCase(branchIfNotObject(regT0));

emitValueProfilingSite(bytecode.metadata(m_codeBlock), regT0);

if (srcVReg != dstVReg)

emitPutVirtualRegister(dstVReg);

}

void JIT::emit_op_catch(const Instruction* currentInstruction)

{

auto bytecode = currentInstruction->as<OpCatch>();

restoreCalleeSavesFromEntryFrameCalleeSavesBuffer(vm().topEntryFrame);

move(TrustedImmPtr(m_vm), regT3);

load64(Address(regT3, VM::callFrameForCatchOffset()), callFrameRegister);

storePtr(TrustedImmPtr(nullptr), Address(regT3, VM::callFrameForCatchOffset()));

addPtr(TrustedImm32(stackPointerOffsetFor(codeBlock()) * sizeof(Register)), callFrameRegister, stackPointerRegister);

callOperationNoExceptionCheck(operationRetrieveAndClearExceptionIfCatchable, &vm());

Jump isCatchableException = branchTest32(NonZero, returnValueGPR);

jumpToExceptionHandler(vm());