C++ emitNakedCall函数代码示例

void JIT::compileCallEvalSlowCase(Instruction* instruction, Vector<SlowCaseEntry>::iterator& iter)
{
    CallLinkInfo* info = m_codeBlock->addCallLinkInfo();
    info->setUpCall(CallLinkInfo::Call, CodeOrigin(m_bytecodeOffset), regT0);

    linkSlowCase(iter);

    int registerOffset = -instruction[4].u.operand;

    addPtr(TrustedImm32(registerOffset * sizeof(Register) + sizeof(CallerFrameAndPC)), callFrameRegister, stackPointerRegister);

    loadPtr(Address(stackPointerRegister, sizeof(Register) * JSStack::Callee - sizeof(CallerFrameAndPC)), regT0);
    loadPtr(Address(stackPointerRegister, sizeof(Register) * JSStack::Callee - sizeof(CallerFrameAndPC)), regT1);
    move(TrustedImmPtr(info), regT2);

    emitLoad(JSStack::Callee, regT1, regT0);
    MacroAssemblerCodeRef virtualThunk = virtualThunkFor(m_vm, *info);
    info->setSlowStub(createJITStubRoutine(virtualThunk, *m_vm, nullptr, true));
    emitNakedCall(virtualThunk.code());
    addPtr(TrustedImm32(stackPointerOffsetFor(m_codeBlock) * sizeof(Register)), callFrameRegister, stackPointerRegister);
    checkStackPointerAlignment();

    sampleCodeBlock(m_codeBlock);
    
    emitPutCallResult(instruction);
}

void JIT::compileOpCall(OpcodeID opcodeID, Instruction* instruction, unsigned callLinkInfoIndex)
{
    int callee = instruction[1].u.operand;

    /* Caller always:
        - Updates callFrameRegister to callee callFrame.
        - Initializes ArgumentCount; CallerFrame; Callee.

       For a JS call:
        - Caller initializes ScopeChain.
        - Callee initializes ReturnPC; CodeBlock.
        - Callee restores callFrameRegister before return.

       For a non-JS call:
        - Caller initializes ScopeChain; ReturnPC; CodeBlock.
        - Caller restores callFrameRegister after return.
    */
    
    if (opcodeID == op_call_varargs)
        compileLoadVarargs(instruction);
    else {
        int argCount = instruction[2].u.operand;
        int registerOffset = instruction[3].u.operand;

        addPtr(TrustedImm32(registerOffset * sizeof(Register)), callFrameRegister, regT3);

        store32(TrustedImm32(argCount), payloadFor(RegisterFile::ArgumentCount, regT3));
    } // regT3 holds newCallFrame with ArgumentCount initialized.
    emitLoad(callee, regT1, regT0); // regT1, regT0 holds callee.

    storePtr(callFrameRegister, Address(regT3, RegisterFile::CallerFrame * static_cast<int>(sizeof(Register))));
    emitStore(RegisterFile::Callee, regT1, regT0, regT3);
    move(regT3, callFrameRegister);

    if (opcodeID == op_call_eval) {
        compileCallEval();
        return;
    }

    DataLabelPtr addressOfLinkedFunctionCheck;
    BEGIN_UNINTERRUPTED_SEQUENCE(sequenceOpCall);
    Jump slowCase = branchPtrWithPatch(NotEqual, regT0, addressOfLinkedFunctionCheck, TrustedImmPtr(0));
    END_UNINTERRUPTED_SEQUENCE(sequenceOpCall);

    addSlowCase(slowCase);
    addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)));

    ASSERT_JIT_OFFSET(differenceBetween(addressOfLinkedFunctionCheck, slowCase), patchOffsetOpCallCompareToJump);
    ASSERT(m_callStructureStubCompilationInfo.size() == callLinkInfoIndex);
    m_callStructureStubCompilationInfo.append(StructureStubCompilationInfo());
    m_callStructureStubCompilationInfo[callLinkInfoIndex].hotPathBegin = addressOfLinkedFunctionCheck;
    m_callStructureStubCompilationInfo[callLinkInfoIndex].callType = CallLinkInfo::callTypeFor(opcodeID);
    m_callStructureStubCompilationInfo[callLinkInfoIndex].bytecodeIndex = m_bytecodeOffset;

    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_scopeChain)), regT1);
    emitPutCellToCallFrameHeader(regT1, RegisterFile::ScopeChain);
    m_callStructureStubCompilationInfo[callLinkInfoIndex].hotPathOther = emitNakedCall();

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileOpCallSlowCase(OpcodeID opcodeID, Instruction* instruction, Vector<SlowCaseEntry>::iterator& iter, unsigned callLinkInfoIndex)
{
    if (opcodeID == op_call_eval) {
        compileCallEvalSlowCase(instruction, iter);
        return;
    }

    linkSlowCase(iter);

    if (opcodeID == op_tail_call || opcodeID == op_tail_call_varargs || opcodeID == op_tail_call_forward_arguments)
        emitRestoreCalleeSaves();

    move(TrustedImmPtr(m_callCompilationInfo[callLinkInfoIndex].callLinkInfo), regT2);

    m_callCompilationInfo[callLinkInfoIndex].callReturnLocation = emitNakedCall(m_vm->getCTIStub(linkCallThunkGenerator).code());

    if (opcodeID == op_tail_call || opcodeID == op_tail_call_varargs) {
        abortWithReason(JITDidReturnFromTailCall);
        return;
    }

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

    sampleCodeBlock(m_codeBlock);
    
    emitPutCallResult(instruction);
}

void JIT::compileOpCall(OpcodeID opcodeID, Instruction* instruction, unsigned)
{
    int callee = instruction[1].u.operand;
    int argCount = instruction[2].u.operand;
    int registerOffset = instruction[3].u.operand;

    // Handle eval
    Jump wasEval;
    if (opcodeID == op_call_eval) {
        JITStubCall stubCall(this, cti_op_call_eval);
        stubCall.addArgument(callee, regT0);
        stubCall.addArgument(JIT::Imm32(registerOffset));
        stubCall.addArgument(JIT::Imm32(argCount));
        stubCall.call();
        wasEval = branchPtr(NotEqual, regT0, TrustedImmPtr(JSValue::encode(JSValue())));
    }

    emitGetVirtualRegister(callee, regT0);

    // Check for JSFunctions.
    emitJumpSlowCaseIfNotJSCell(regT0);
    addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsFunctionVPtr)));

    // Speculatively roll the callframe, assuming argCount will match the arity.
    storePtr(callFrameRegister, Address(callFrameRegister, (RegisterFile::CallerFrame + registerOffset) * static_cast<int>(sizeof(Register))));
    addPtr(Imm32(registerOffset * static_cast<int>(sizeof(Register))), callFrameRegister);
    move(Imm32(argCount), regT1);

    emitNakedCall(opcodeID == op_construct ? m_globalData->jitStubs->ctiVirtualConstruct() : m_globalData->jitStubs->ctiVirtualCall());

    if (opcodeID == op_call_eval)
        wasEval.link(this);

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileOpCallVarargs(Instruction* instruction)
{
    int callee = instruction[1].u.operand;
    int argCountRegister = instruction[2].u.operand;
    int registerOffset = instruction[3].u.operand;

    emitGetVirtualRegister(argCountRegister, regT1);
    emitFastArithImmToInt(regT1);
    emitGetVirtualRegister(callee, regT0);
    addPtr(Imm32(registerOffset), regT1, regT2);

    // Check for JSFunctions.
    emitJumpSlowCaseIfNotJSCell(regT0);
    addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsFunctionVPtr)));

    // Speculatively roll the callframe, assuming argCount will match the arity.
    mul32(TrustedImm32(sizeof(Register)), regT2, regT2);
    intptr_t offset = (intptr_t)sizeof(Register) * (intptr_t)RegisterFile::CallerFrame;
    addPtr(Imm32((int32_t)offset), regT2, regT3);
    addPtr(callFrameRegister, regT3);
    storePtr(callFrameRegister, regT3);
    addPtr(regT2, callFrameRegister);
    emitNakedCall(m_globalData->jitStubs->ctiVirtualCall());

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileOpCallSlowCase(Instruction* instruction, Vector<SlowCaseEntry>::iterator& iter, unsigned callLinkInfoIndex, OpcodeID opcodeID)
{
    int argCount = instruction[2].u.operand;
    int registerOffset = instruction[3].u.operand;

    linkSlowCase(iter);

    // Fast check for JS function.
    Jump callLinkFailNotObject = emitJumpIfNotJSCell(regT0);
    Jump callLinkFailNotJSFunction = branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsFunctionVPtr));

    // Speculatively roll the callframe, assuming argCount will match the arity.
    storePtr(callFrameRegister, Address(callFrameRegister, (RegisterFile::CallerFrame + registerOffset) * static_cast<int>(sizeof(Register))));
    addPtr(Imm32(registerOffset * static_cast<int>(sizeof(Register))), callFrameRegister);
    move(Imm32(argCount), regT1);

    m_callStructureStubCompilationInfo[callLinkInfoIndex].callReturnLocation = emitNakedCall(opcodeID == op_construct ? m_globalData->jitStubs->ctiVirtualConstructLink() : m_globalData->jitStubs->ctiVirtualCallLink());

    // Done! - return back to the hot path.
    ASSERT(OPCODE_LENGTH(op_call) == OPCODE_LENGTH(op_call_eval));
    ASSERT(OPCODE_LENGTH(op_call) == OPCODE_LENGTH(op_construct));
    emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_call));

    // This handles host functions
    callLinkFailNotObject.link(this);
    callLinkFailNotJSFunction.link(this);

    JITStubCall stubCall(this, opcodeID == op_construct ? cti_op_construct_NotJSConstruct : cti_op_call_NotJSFunction);
    stubCall.addArgument(regT0);
    stubCall.addArgument(JIT::Imm32(registerOffset));
    stubCall.addArgument(JIT::Imm32(argCount));
    stubCall.call();

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileOpCallVarargs(Instruction* instruction)
{
    int callee = instruction[1].u.operand;
    int argCountRegister = instruction[2].u.operand;
    int registerOffset = instruction[3].u.operand;

    emitLoad(callee, regT1, regT0);
    emitLoadPayload(argCountRegister, regT2); // argCount
    addPtr(Imm32(registerOffset), regT2, regT3); // registerOffset

    emitJumpSlowCaseIfNotJSCell(callee, regT1);
    addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsFunctionVPtr)));

    // Speculatively roll the callframe, assuming argCount will match the arity.
    mul32(TrustedImm32(sizeof(Register)), regT3, regT3);
    addPtr(callFrameRegister, regT3);
    store32(TrustedImm32(JSValue::CellTag), tagFor(RegisterFile::CallerFrame, regT3));
    storePtr(callFrameRegister, payloadFor(RegisterFile::CallerFrame, regT3));
    move(regT3, callFrameRegister);

    move(regT2, regT1); // argCount

    emitNakedCall(m_globalData->jitStubs->ctiVirtualCall());

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileOpCall(OpcodeID opcodeID, Instruction* instruction, unsigned callLinkInfoIndex)
{
    int callee = instruction[1].u.operand;
    int argCount = instruction[2].u.operand;
    int registerOffset = instruction[3].u.operand;

    Jump wasEval;
    if (opcodeID == op_call_eval) {
        JITStubCall stubCall(this, cti_op_call_eval);
        stubCall.addArgument(callee);
        stubCall.addArgument(JIT::Imm32(registerOffset));
        stubCall.addArgument(JIT::Imm32(argCount));
        stubCall.call();
        wasEval = branch32(NotEqual, regT1, TrustedImm32(JSValue::EmptyValueTag));
    }

    emitLoad(callee, regT1, regT0);

    DataLabelPtr addressOfLinkedFunctionCheck;

    BEGIN_UNINTERRUPTED_SEQUENCE(sequenceOpCall);

    Jump jumpToSlow = branchPtrWithPatch(NotEqual, regT0, addressOfLinkedFunctionCheck, TrustedImmPtr(0));

    END_UNINTERRUPTED_SEQUENCE(sequenceOpCall);

    addSlowCase(jumpToSlow);
    ASSERT_JIT_OFFSET(differenceBetween(addressOfLinkedFunctionCheck, jumpToSlow), patchOffsetOpCallCompareToJump);
    ASSERT(m_callStructureStubCompilationInfo.size() == callLinkInfoIndex);
    m_callStructureStubCompilationInfo.append(StructureStubCompilationInfo());
    m_callStructureStubCompilationInfo[callLinkInfoIndex].hotPathBegin = addressOfLinkedFunctionCheck;
    m_callStructureStubCompilationInfo[callLinkInfoIndex].isCall = opcodeID != op_construct;
    m_callStructureStubCompilationInfo[callLinkInfoIndex].bytecodeIndex = m_bytecodeOffset;

    addSlowCase(branch32(NotEqual, regT1, TrustedImm32(JSValue::CellTag)));

    // The following is the fast case, only used whan a callee can be linked.

    // Fast version of stack frame initialization, directly relative to edi.
    // Note that this omits to set up RegisterFile::CodeBlock, which is set in the callee
    loadPtr(Address(regT0, OBJECT_OFFSETOF(JSFunction, m_scopeChain)), regT2);

    store32(TrustedImm32(JSValue::Int32Tag), tagFor(registerOffset + RegisterFile::ArgumentCount));
    store32(Imm32(argCount), payloadFor(registerOffset + RegisterFile::ArgumentCount));
    storePtr(callFrameRegister, payloadFor(RegisterFile::CallerFrame + registerOffset, callFrameRegister));
    emitStore(registerOffset + RegisterFile::Callee, regT1, regT0);
    store32(TrustedImm32(JSValue::CellTag), tagFor(registerOffset + RegisterFile::ScopeChain));
    store32(regT2, payloadFor(registerOffset + RegisterFile::ScopeChain));
    addPtr(Imm32(registerOffset * sizeof(Register)), callFrameRegister);

    // Call to the callee
    m_callStructureStubCompilationInfo[callLinkInfoIndex].hotPathOther = emitNakedCall();
    
    if (opcodeID == op_call_eval)
        wasEval.link(this);

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileCallEvalSlowCase(Vector<SlowCaseEntry>::iterator& iter)
{
    linkSlowCase(iter);

    emitLoad(RegisterFile::Callee, regT1, regT0);
    emitNakedCall(m_globalData->jitStubs->ctiVirtualCall());

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileCallEvalSlowCase(Vector<SlowCaseEntry>::iterator& iter)
{
    linkSlowCase(iter);

    emitGetFromCallFrameHeaderPtr(JSStack::Callee, regT0);
    emitNakedCall(m_globalData->jitStubs->ctiVirtualCall());

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileCallEvalSlowCase(Vector<SlowCaseEntry>::iterator& iter)
{
    linkSlowCase(iter);

    emitGetFromCallFrameHeader64(JSStack::Callee, regT0);
    emitNakedCall(m_globalData->getCTIStub(virtualCallGenerator).code());

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileCallEvalSlowCase(Vector<SlowCaseEntry>::iterator& iter)
{
    linkSlowCase(iter);

    emitLoad(JSStack::Callee, regT1, regT0);
    emitNakedCall(m_vm->getCTIStub(virtualCallGenerator).code());

    sampleCodeBlock(m_codeBlock);
}

void JIT::compileCallEvalSlowCase(Instruction* instruction, Vector<SlowCaseEntry>::iterator& iter)
{
    linkSlowCase(iter);

    emitGetFromCallFrameHeader64(JSStack::Callee, regT0);
    emitNakedCall(m_vm->getCTIStub(oldStyleVirtualCallGenerator).code());

    sampleCodeBlock(m_codeBlock);
    
    emitPutCallResult(instruction);
}

void JIT::compileOpCall(OpcodeID opcodeID, Instruction* instruction, unsigned i, unsigned)
{
    int dst = instruction[1].u.operand;
    int callee = instruction[2].u.operand;
    int argCount = instruction[3].u.operand;
    int registerOffset = instruction[4].u.operand;

    // Handle eval
    JmpSrc wasEval;
    if (opcodeID == op_call_eval) {
        emitGetVirtualRegister(callee, X86::ecx, i);
        compileOpCallEvalSetupArgs(instruction);

        emitCTICall(i, Interpreter::cti_op_call_eval);
        __ cmpl_i32r(asInteger(JSImmediate::impossibleValue()), X86::eax);
        wasEval = __ jne();
    }

    emitGetVirtualRegister(callee, X86::ecx, i);
    // The arguments have been set up on the hot path for op_call_eval
    if (opcodeID == op_call)
        compileOpCallSetupArgs(instruction);
    else if (opcodeID == op_construct)
        compileOpConstructSetupArgs(instruction);

    // Check for JSFunctions.
    emitJumpSlowCaseIfNotJSCell(X86::ecx, i);
    __ cmpl_i32m(reinterpret_cast<unsigned>(m_interpreter->m_jsFunctionVptr), X86::ecx);
    m_slowCases.append(SlowCaseEntry(__ jne(), i));

    // First, in the case of a construct, allocate the new object.
    if (opcodeID == op_construct) {
        emitCTICall(i, Interpreter::cti_op_construct_JSConstruct);
        emitPutVirtualRegister(registerOffset - RegisterFile::CallFrameHeaderSize - argCount);
        emitGetVirtualRegister(callee, X86::ecx, i);
    }

    // Speculatively roll the callframe, assuming argCount will match the arity.
    __ movl_rm(X86::edi, (RegisterFile::CallerFrame + registerOffset) * static_cast<int>(sizeof(Register)), X86::edi);
    __ addl_i32r(registerOffset * static_cast<int>(sizeof(Register)), X86::edi);
    __ movl_i32r(argCount, X86::edx);

    emitNakedCall(i, m_interpreter->m_ctiVirtualCall);

    if (opcodeID == op_call_eval)
        __ link(wasEval, __ label());

    // Put the return value in dst. In the interpreter, op_ret does this.
    emitPutVirtualRegister(dst);

#if ENABLE(CODEBLOCK_SAMPLING)
    __ movl_i32m(reinterpret_cast<unsigned>(m_codeBlock), m_interpreter->sampler()->codeBlockSlot());
#endif
}

void JIT::compileOpCallSlowCase(OpcodeID opcodeID, Instruction*, Vector<SlowCaseEntry>::iterator& iter, unsigned callLinkInfoIndex)
{
    if (opcodeID == op_call_eval) {
        compileCallEvalSlowCase(iter);
        return;
    }

    linkSlowCase(iter);
    
    m_callStructureStubCompilationInfo[callLinkInfoIndex].callReturnLocation = emitNakedCall(opcodeID == op_construct ? m_globalData->getCTIStub(linkConstructGenerator).code() : m_globalData->getCTIStub(linkCallGenerator).code());

    sampleCodeBlock(m_codeBlock);
}