Пример #1
0
void JIT::compileLoadVarargs(Instruction* instruction)
{
    int thisValue = instruction[3].u.operand;
    int arguments = instruction[4].u.operand;
    int firstFreeRegister = instruction[5].u.operand;

    JumpList slowCase;
    JumpList end;
    bool canOptimize = m_codeBlock->usesArguments()
        && arguments == m_codeBlock->argumentsRegister().offset()
        && !m_codeBlock->symbolTable()->slowArguments();

    if (canOptimize) {
        emitGetVirtualRegister(arguments, regT0);
        slowCase.append(branch64(NotEqual, regT0, TrustedImm64(JSValue::encode(JSValue()))));

        emitGetFromCallFrameHeader32(JSStack::ArgumentCount, regT0);
        slowCase.append(branch32(Above, regT0, TrustedImm32(Arguments::MaxArguments + 1)));
        // regT0: argumentCountIncludingThis

        move(regT0, regT1);
        neg64(regT1);
        add64(TrustedImm32(firstFreeRegister - JSStack::CallFrameHeaderSize), regT1);
        lshift64(TrustedImm32(3), regT1);
        addPtr(callFrameRegister, regT1);
        // regT1: newCallFrame

        slowCase.append(branchPtr(Above, AbsoluteAddress(m_vm->addressOfJSStackLimit()), regT1));

        // Initialize ArgumentCount.
        store32(regT0, Address(regT1, JSStack::ArgumentCount * static_cast<int>(sizeof(Register)) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.payload)));

        // Initialize 'this'.
        emitGetVirtualRegister(thisValue, regT2);
        store64(regT2, Address(regT1, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));

        // Copy arguments.
        signExtend32ToPtr(regT0, regT0);
        end.append(branchSub64(Zero, TrustedImm32(1), regT0));
        // regT0: argumentCount

        Label copyLoop = label();
        load64(BaseIndex(callFrameRegister, regT0, TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))), regT2);
        store64(regT2, BaseIndex(regT1, regT0, TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));
        branchSub64(NonZero, TrustedImm32(1), regT0).linkTo(copyLoop, this);

        end.append(jump());
    }

    if (canOptimize)
        slowCase.link(this);

    emitGetVirtualRegister(thisValue, regT0);
    emitGetVirtualRegister(arguments, regT1);
    callOperation(operationLoadVarargs, regT0, regT1, firstFreeRegister);
    move(returnValueGPR, regT1);

    if (canOptimize)
        end.link(this);
}
Пример #2
0
void JIT::compileLoadVarargs(Instruction* instruction)
{
    int thisValue = instruction[2].u.operand;
    int arguments = instruction[3].u.operand;
    int firstFreeRegister = instruction[4].u.operand;

    killLastResultRegister();

    JumpList slowCase;
    JumpList end;
    if (m_codeBlock->usesArguments() && arguments == m_codeBlock->argumentsRegister()) {
        emitGetVirtualRegister(arguments, regT0);
        slowCase.append(branchPtr(NotEqual, regT0, TrustedImmPtr(JSValue::encode(JSValue()))));

        emitGetFromCallFrameHeader32(RegisterFile::ArgumentCount, regT0);
        slowCase.append(branch32(Above, regT0, TrustedImm32(Arguments::MaxArguments + 1)));
        // regT0: argumentCountIncludingThis

        move(regT0, regT1);
        add32(TrustedImm32(firstFreeRegister + RegisterFile::CallFrameHeaderSize), regT1);
        lshift32(TrustedImm32(3), regT1);
        addPtr(callFrameRegister, regT1);
        // regT1: newCallFrame

        slowCase.append(branchPtr(Below, AbsoluteAddress(m_globalData->interpreter->registerFile().addressOfEnd()), regT1));

        // Initialize ArgumentCount.
        emitFastArithReTagImmediate(regT0, regT2);
        storePtr(regT2, Address(regT1, RegisterFile::ArgumentCount * static_cast<int>(sizeof(Register))));

        // Initialize 'this'.
        emitGetVirtualRegister(thisValue, regT2);
        storePtr(regT2, Address(regT1, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));

        // Copy arguments.
        neg32(regT0);
        signExtend32ToPtr(regT0, regT0);
        end.append(branchAddPtr(Zero, Imm32(1), regT0));
        // regT0: -argumentCount

        Label copyLoop = label();
        loadPtr(BaseIndex(callFrameRegister, regT0, TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))), regT2);
        storePtr(regT2, BaseIndex(regT1, regT0, TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));
        branchAddPtr(NonZero, Imm32(1), regT0).linkTo(copyLoop, this);

        end.append(jump());
    }

    if (m_codeBlock->usesArguments() && arguments == m_codeBlock->argumentsRegister())
        slowCase.link(this);

    JITStubCall stubCall(this, cti_op_load_varargs);
    stubCall.addArgument(thisValue, regT0);
    stubCall.addArgument(arguments, regT0);
    stubCall.addArgument(Imm32(firstFreeRegister));
    stubCall.call(regT1);

    if (m_codeBlock->usesArguments() && arguments == m_codeBlock->argumentsRegister())
        end.link(this);
}
Пример #3
0
void JIT::compileLoadVarargs(Instruction* instruction)
{
    int thisValue = instruction[3].u.operand;
    int arguments = instruction[4].u.operand;
    int firstFreeRegister = instruction[5].u.operand;
    int firstVarArgOffset = instruction[6].u.operand;

    JumpList slowCase;
    JumpList end;
    bool canOptimize = m_codeBlock->usesArguments()
        && arguments == m_codeBlock->argumentsRegister().offset()
        && !m_codeBlock->symbolTable()->slowArguments();

    if (canOptimize) {
        emitGetVirtualRegister(arguments, regT0);
        slowCase.append(branch64(NotEqual, regT0, TrustedImm64(JSValue::encode(JSValue()))));

        emitGetFromCallFrameHeader32(JSStack::ArgumentCount, regT0);
        if (firstVarArgOffset) {
            Jump sufficientArguments = branch32(GreaterThan, regT0, TrustedImm32(firstVarArgOffset + 1));
            move(TrustedImm32(1), regT0);
            Jump endVarArgs = jump();
            sufficientArguments.link(this);
            sub32(TrustedImm32(firstVarArgOffset), regT0);
            endVarArgs.link(this);
        }
        slowCase.append(branch32(Above, regT0, TrustedImm32(Arguments::MaxArguments + 1)));
        // regT0: argumentCountIncludingThis
        move(regT0, regT1);
        add64(TrustedImm32(-firstFreeRegister + JSStack::CallFrameHeaderSize), regT1);
        // regT1 now has the required frame size in Register units
        // Round regT1 to next multiple of stackAlignmentRegisters()
        add64(TrustedImm32(stackAlignmentRegisters() - 1), regT1);
        and64(TrustedImm32(~(stackAlignmentRegisters() - 1)), regT1);

        neg64(regT1);
        lshift64(TrustedImm32(3), regT1);
        addPtr(callFrameRegister, regT1);
        // regT1: newCallFrame

        slowCase.append(branchPtr(Above, AbsoluteAddress(m_vm->addressOfStackLimit()), regT1));

        // Initialize ArgumentCount.
        store32(regT0, Address(regT1, JSStack::ArgumentCount * static_cast<int>(sizeof(Register)) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.payload)));

        // Initialize 'this'.
        emitGetVirtualRegister(thisValue, regT2);
        store64(regT2, Address(regT1, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));

        // Copy arguments.
        signExtend32ToPtr(regT0, regT0);
        end.append(branchSub64(Zero, TrustedImm32(1), regT0));
        // regT0: argumentCount

        Label copyLoop = label();
        load64(BaseIndex(callFrameRegister, regT0, TimesEight, (CallFrame::thisArgumentOffset() + firstVarArgOffset) * static_cast<int>(sizeof(Register))), regT2);
        store64(regT2, BaseIndex(regT1, regT0, TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));
        branchSub64(NonZero, TrustedImm32(1), regT0).linkTo(copyLoop, this);

        end.append(jump());
    }

    if (canOptimize)
        slowCase.link(this);

    emitGetVirtualRegister(arguments, regT1);
    callOperation(operationSizeFrameForVarargs, regT1, firstFreeRegister, firstVarArgOffset);
    move(returnValueGPR, stackPointerRegister);
    emitGetVirtualRegister(thisValue, regT1);
    emitGetVirtualRegister(arguments, regT2);
    callOperation(operationLoadVarargs, returnValueGPR, regT1, regT2, firstVarArgOffset);
    move(returnValueGPR, regT1);

    if (canOptimize)
        end.link(this);
    
    addPtr(TrustedImm32(sizeof(CallerFrameAndPC)), regT1, stackPointerRegister);
}