C++ Address函數代碼示例

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;

        if (opcodeID == op_call && shouldEmitProfiling()) {
            emitGetVirtualRegister(registerOffset + CallFrame::argumentOffsetIncludingThis(0), regT0);
            Jump done = emitJumpIfNotJSCell(regT0);
            loadPtr(Address(regT0, JSCell::structureOffset()), regT0);
            storePtr(regT0, instruction[5].u.arrayProfile->addressOfLastSeenStructure());
            done.link(this);
        }

        addPtr(TrustedImm32(registerOffset * sizeof(Register)), callFrameRegister, regT1);
        store32(TrustedImm32(argCount), Address(regT1, JSStack::ArgumentCount * static_cast<int>(sizeof(Register)) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.payload)));
    } // regT1 holds newCallFrame with ArgumentCount initialized.

    store32(TrustedImm32(instruction - m_codeBlock->instructions().begin()), Address(callFrameRegister, JSStack::ArgumentCount * static_cast<int>(sizeof(Register)) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.tag)));
    emitGetVirtualRegister(callee, regT0); // regT0 holds callee.

    store64(callFrameRegister, Address(regT1, JSStack::CallerFrame * static_cast<int>(sizeof(Register))));
    store64(regT0, Address(regT1, JSStack::Callee * static_cast<int>(sizeof(Register))));
    move(regT1, 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);

    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_scope)), regT1);
    emitPutToCallFrameHeader(regT1, JSStack::ScopeChain);
    m_callStructureStubCompilationInfo[callLinkInfoIndex].hotPathOther = emitNakedCall();

    sampleCodeBlock(m_codeBlock);
}

char* StubRoutines::generate_megamorphic_ic(MacroAssembler* masm) {
// Called from within a MIC (megamorphic inline cache), the special
// variant of PICs for compiled code (see compiledPIC.hpp/cpp).
// The MIC layout is as follows:
//
// call <this stub routine>
// selector			<--- return address (tos)
//
// Note: Don't use this for megamorphic super sends!

    Label is_smi, probe_primary_cache, probe_secondary_cache, call_method, is_methodOop, do_lookup;

    masm->bind(is_smi);				// smi case (assumed to be infrequent)
    masm->movl(ecx, Address((int)&smiKlassObj, relocInfo::external_word_type));
    masm->jmp(probe_primary_cache);

    // eax    : receiver
    // tos    : return address pointing to selector in MIC
    // tos + 4: return address of megamorphic send in compiled code
    // tos + 8: last argument/receiver
    char* entry_point = masm->pc();
    masm->popl(ebx);				// get return address (MIC cache)
    masm->test(eax, Mem_Tag);			// check if smi
    masm->jcc(Assembler::zero, is_smi);		// if so, get smi class directly
    masm->movl(ecx, Address(eax, memOopDesc::klass_byte_offset()));	// otherwise, load receiver class

    // probe primary cache
    //
    // eax: receiver
    // ebx: MIC cache pointer
    // ecx: receiver klass
    // tos: return address of megamorphic send in compiled code (ic)
    masm->bind(probe_primary_cache);		// compute hash value
    masm->movl(edx, Address(ebx));		// get selector
    // compute hash value
    masm->movl(edi, ecx);
    masm->xorl(edi, edx);
    masm->andl(edi, (primary_cache_size - 1) << 4);
    // probe cache
    masm->cmpl(ecx, Address(edi, lookupCache::primary_cache_address() + 0*oopSize));
    masm->jcc(Assembler::notEqual, probe_secondary_cache);
    masm->cmpl(edx, Address(edi, lookupCache::primary_cache_address() + 1*oopSize));
    masm->jcc(Assembler::notEqual, probe_secondary_cache);
    masm->movl(ecx, Address(edi, lookupCache::primary_cache_address() + 2*oopSize));

    // call method
    //
    // eax: receiver
    // ecx: methodOop/nmethod
    // tos: return address of megamorphic send in compiled code (ic)
    masm->bind(call_method);
    masm->test(ecx, Mem_Tag);			// check if methodOop
    masm->jcc(Assembler::notZero, is_methodOop);	// otherwise
    masm->jmp(ecx);				// call nmethod

    // call methodOop - setup registers
    masm->bind(is_methodOop);
    masm->xorl(ebx, ebx);				// clear ebx for interpreter
    masm->movl(edx, Address(int(&method_entry_point), relocInfo::external_word_type));
    // (Note: cannot use value in method_entry_point directly since interpreter is generated afterwards)
    //
    // eax: receiver
    // ebx: 00000000
    // ecx: methodOop
    // edx: entry point
    // tos: return address of megamorphic send in compiled code (ic)
    masm->jmp(edx);				// call method_entry

    // probe secondary cache
    //
    // eax: receiver
    // ebx: MIC cache pointer
    // ecx: receiver klass
    // edx: selector
    // edi: primary cache index
    // tos: return address of megamorphic send in compiled code (ic)
    masm->bind(probe_secondary_cache);		// compute hash value
    masm->andl(edi, (secondary_cache_size - 1) << 4);
    // probe cache
    masm->cmpl(ecx, Address(edi, lookupCache::secondary_cache_address() + 0*oopSize));
    masm->jcc(Assembler::notEqual, do_lookup);
    masm->cmpl(edx, Address(edi, lookupCache::secondary_cache_address() + 1*oopSize));
    masm->jcc(Assembler::notEqual, do_lookup);
    masm->movl(ecx, Address(edi, lookupCache::secondary_cache_address() + 2*oopSize));
    masm->jmp(call_method);

    // do lookup
    //
    // eax: receiver
    // ebx: MIC cache pointer
    // ecx: receiver klass
    // edx: selector
    // edi: secondary cache index
    // tos: return address of megamorphic send in compiled code (ic)
    masm->bind(do_lookup);
    masm->set_last_Delta_frame_after_call();
    masm->pushl(eax);				// save receiver
    masm->pushl(edx);				// pass 2nd argument: selector
    masm->pushl(ecx);				// pass 1st argument: receiver klass
    masm->call((char*)lookupCache::normal_lookup, relocInfo::runtime_call_type);
//.........這裏部分代碼省略.........

char* StubRoutines::generate_PIC_stub(MacroAssembler* masm, int pic_size) {
// Called from within a PIC (polymorphic inline cache).
// The stub interprets the methodOop section of compiled PICs.
// The methodOop section layout is as follows:
//
// call <this stub routine>
// cached klass 1	<--- return address (tos)
// cached methodOop 1
// cached klass 2
// cached methodOop2
// ...
//
// cached klass n
// cached methodOop n
//
// Note: Don't use this for polymorphic super sends!

    Label found, loop;

    // entry found at index
    //
    // eax: receiver
    // ebx: PIC table pointer
    // ecx: methodOop
    // edx: receiver klass
    // tos: return address of polymorphic send in compiled code
    masm->bind(found);
    masm->movl(edx, Address(int(&method_entry_point), relocInfo::external_word_type));
    // (Note: cannot use value in method_entry_point directly since interpreter is generated afterwards)
    masm->xorl(ebx, ebx);
    // eax: receiver
    // ebx: 000000xx
    // ecx: methodOop
    masm->jmp(edx);

    // eax    : receiver
    // tos    : return address pointing to table in PIC
    // tos + 4: return address of polymorphic send in compiled code
    // tos + 8: last argument/receiver
    char* entry_point = masm->pc();
    masm->popl(ebx);				// get return address (PIC table pointer)
    masm->movl(edx, Address((int)&smiKlassObj, relocInfo::external_word_type));
    masm->test(eax, Mem_Tag);			// check if smi
    masm->jcc(Assembler::zero, loop);		// if so, class is already in ecx
    masm->movl(edx, Address(eax, memOopDesc::klass_byte_offset()));	// otherwise, load receiver class

    // eax: receiver
    // ebx: PIC table pointer
    // edx: receiver klass
    // tos: return address of polymorphic send in compiled code
    masm->bind(loop);
    for (int i = 0; i < pic_size; i++) {
        // compare receiver klass with klass in PIC table at index
        masm->cmpl(edx, Address(ebx, i * PIC::PIC_methodOop_entry_size + PIC::PIC_methodOop_klass_offset));
        masm->movl(ecx, Address(ebx, i * PIC::PIC_methodOop_entry_size + PIC::PIC_methodOop_offset));
        masm->jcc(Assembler::equal, found);
    }
    assert(ic_normal_lookup_entry() != NULL, "ic_normal_lookup_entry must be generated before");
    masm->jmp(ic_normal_lookup_entry(), relocInfo::runtime_call_type);

    return entry_point;
}

 Address operator&(uintptr_t mask) const {
   return Address(reinterpret_cast<void*>(address_ & mask));
 }

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

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

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

       For a non-JS call:
        - Caller initializes ReturnPC; CodeBlock.
        - Caller restores callFrameRegister after return.
    */
    CallLinkInfo* info;
    if (opcodeID != op_call_eval)
        info = m_codeBlock->addCallLinkInfo();
    if (opcodeID == op_call_varargs || opcodeID == op_construct_varargs)
        compileSetupVarargsFrame(instruction, info);
    else {
        int argCount = instruction[3].u.operand;
        int registerOffset = -instruction[4].u.operand;
        
        if (opcodeID == op_call && shouldEmitProfiling()) {
            emitLoad(registerOffset + CallFrame::argumentOffsetIncludingThis(0), regT0, regT1);
            Jump done = branch32(NotEqual, regT0, TrustedImm32(JSValue::CellTag));
            loadPtr(Address(regT1, JSCell::structureIDOffset()), regT1);
            storePtr(regT1, instruction[OPCODE_LENGTH(op_call) - 2].u.arrayProfile->addressOfLastSeenStructureID());
            done.link(this);
        }
    
        addPtr(TrustedImm32(registerOffset * sizeof(Register) + sizeof(CallerFrameAndPC)), callFrameRegister, stackPointerRegister);

        store32(TrustedImm32(argCount), Address(stackPointerRegister, JSStack::ArgumentCount * static_cast<int>(sizeof(Register)) + PayloadOffset - sizeof(CallerFrameAndPC)));
    } // SP holds newCallFrame + sizeof(CallerFrameAndPC), with ArgumentCount initialized.
    
    uint32_t locationBits = CallSiteIndex(instruction).bits();
    store32(TrustedImm32(locationBits), tagFor(JSStack::ArgumentCount, callFrameRegister));
    emitLoad(callee, regT1, regT0); // regT1, regT0 holds callee.

    store32(regT0, Address(stackPointerRegister, JSStack::Callee * static_cast<int>(sizeof(Register)) + PayloadOffset - sizeof(CallerFrameAndPC)));
    store32(regT1, Address(stackPointerRegister, JSStack::Callee * static_cast<int>(sizeof(Register)) + TagOffset - sizeof(CallerFrameAndPC)));

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

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

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

    addSlowCase(slowCase);

    ASSERT(m_callCompilationInfo.size() == callLinkInfoIndex);
    info->setUpCall(CallLinkInfo::callTypeFor(opcodeID), CodeOrigin(m_bytecodeOffset), regT0);
    m_callCompilationInfo.append(CallCompilationInfo());
    m_callCompilationInfo[callLinkInfoIndex].hotPathBegin = addressOfLinkedFunctionCheck;
    m_callCompilationInfo[callLinkInfoIndex].callLinkInfo = info;

    checkStackPointerAlignment();
    m_callCompilationInfo[callLinkInfoIndex].hotPathOther = emitNakedCall();

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

    sampleCodeBlock(m_codeBlock);
    emitPutCallResult(instruction);
}

AssemblyHelpers::JumpList AssemblyHelpers::branchIfNotType(
    JSValueRegs regs, GPRReg tempGPR, const InferredType::Descriptor& descriptor, TagRegistersMode mode)
{
    AssemblyHelpers::JumpList result;

    switch (descriptor.kind()) {
    case InferredType::Bottom:
        result.append(jump());
        break;

    case InferredType::Boolean:
        result.append(branchIfNotBoolean(regs, tempGPR));
        break;

    case InferredType::Other:
        result.append(branchIfNotOther(regs, tempGPR));
        break;

    case InferredType::Int32:
        result.append(branchIfNotInt32(regs, mode));
        break;

    case InferredType::Number:
        result.append(branchIfNotNumber(regs, tempGPR, mode));
        break;

    case InferredType::String:
        result.append(branchIfNotCell(regs, mode));
        result.append(branchIfNotString(regs.payloadGPR()));
        break;

    case InferredType::ObjectWithStructure:
        result.append(branchIfNotCell(regs, mode));
        result.append(
            branchStructure(
                NotEqual,
                Address(regs.payloadGPR(), JSCell::structureIDOffset()),
                descriptor.structure()));
        break;

    case InferredType::ObjectWithStructureOrOther: {
        Jump ok = branchIfOther(regs, tempGPR);
        result.append(branchIfNotCell(regs, mode));
        result.append(
            branchStructure(
                NotEqual,
                Address(regs.payloadGPR(), JSCell::structureIDOffset()),
                descriptor.structure()));
        ok.link(this);
        break;
    }

    case InferredType::Object:
        result.append(branchIfNotCell(regs, mode));
        result.append(branchIfNotObject(regs.payloadGPR()));
        break;

    case InferredType::ObjectOrOther: {
        Jump ok = branchIfOther(regs, tempGPR);
        result.append(branchIfNotCell(regs, mode));
        result.append(branchIfNotObject(regs.payloadGPR()));
        ok.link(this);
        break;
    }

    case InferredType::Top:
        break;
    }

    return result;
}

	Address get(T offset) const {
		return Address(reinterpret_cast<uintptr_t>(m_ptr)+offset);
	}

int main(int argc, const char * argv[])
{
    Buffer buffer;
    Storage disk;
    Record::buffer=&buffer;
    Bptree_node::buffer=&buffer;
    Bptree::buffer=&buffer;
    Record record;
    Table_info table;
    table.table_name="friendg";
    table.database="zyh";
    Attribute attribute;
    Tuple_data tuple_data(90);
    Tuple_info tuple;
    table.tuple_size=21;
    attribute.type=SQL_INT;
    attribute.size=4;
    table.attribute_list.push_back(attribute);
    attribute.type=SQL_STRING;
    attribute.size=6;
    table.attribute_list.push_back(attribute);
    attribute.type=SQL_STRING;
    attribute.size=4;
    table.attribute_list.push_back(attribute);
    attribute.type=SQL_STRING;
    attribute.size=3;
    table.attribute_list.push_back(attribute);
    attribute.attribute_name="result";
    attribute.type=SQL_FLOAT;
    attribute.size=4;
    table.attribute_list.push_back(attribute);
    tuple.info.push_back("44");
    tuple.info.push_back("abcde");
    tuple.info.push_back("ac");
    tuple.info.push_back("ac");
    tuple.info.push_back("44.4");
    Tuple_info tuple_unpack;
    for (int i=0;i<5;i++)
        tuple_unpack.info.push_back("");
    try
    {
        record.pack(table,tuple,&tuple_data);
    }
    catch (Error error)
    {
        error.print_error();
    }
    printf("before unpack\n");
      printf("\n");
    record.unpack(table,&tuple_unpack,&tuple_data);
    for (int i=0;i<5;i++)
        std::cout<<tuple_unpack.info[i]<<std::endl;
    for (int i=0;i<30;i++)
        printf("%X  ",tuple_data.data[i]);
    printf("\n");
    Storage storage;
    record.create_table(table);
    record.insert_tuple(table, tuple_unpack);
    record.insert_tuple(table, tuple_unpack);
    record.insert_tuple(table, tuple_unpack);
    Address del_address;
    del_address=record.int_to_address(table, 12);
    record.delete_tuple(table, del_address);
    del_address=record.int_to_address(table, 41);
    record.delete_tuple(table, del_address);
    record.insert_tuple(table, tuple_unpack);
    Tuple_info new_tuple;
    new_tuple.info.push_back("55");
    new_tuple.info.push_back("qqqq");
    new_tuple.info.push_back("ac");
    new_tuple.info.push_back("ac");
    new_tuple.info.push_back("32.2");
    record.insert_tuple(table, new_tuple);
    Tuple_info get_tuple(5);
    Address next_address;
    record.get_first_tuple(table, &get_tuple, &next_address);
    while (!(next_address.block_offset==0 && next_address.file_offset==0))
    {
        for (int i=0;i<5;i++)
        {
            std::cout<<get_tuple.info[i]<<std::endl;
        }
        std::cout<<"next"<<std::endl;
        Address address=next_address;
        record.get_tuple(table, address,&get_tuple, &next_address);
    }
    for (int i=0;i<5;i++)
    {
        std::cout<<get_tuple.info[i]<<std::endl;
    }
    Bptree bptree;
    Table_info table2;
    table2.table_name="friendindex";
    table2.database="zyh";
    table2.tuple_size=2400;
    attribute.type=SQL_STRING;
    attribute.size=2400;
    table2.attribute_list.push_back(attribute);
//    Tuple_info tuple2;
//    Address add;
//.........這裏部分代碼省略.........

 Address Address::rootAddress()
 {
     return Address();
 }

address TemplateInterpreterGenerator::generate_math_entry(AbstractInterpreter::MethodKind kind) {

  // rbx,: Method*
  // rcx: scratrch
  // rsi: sender sp

  if (!InlineIntrinsics) return NULL; // Generate a vanilla entry

  address entry_point = __ pc();

  // These don't need a safepoint check because they aren't virtually
  // callable. We won't enter these intrinsics from compiled code.
  // If in the future we added an intrinsic which was virtually callable
  // we'd have to worry about how to safepoint so that this code is used.

  // mathematical functions inlined by compiler
  // (interpreter must provide identical implementation
  // in order to avoid monotonicity bugs when switching
  // from interpreter to compiler in the middle of some
  // computation)
  //
  // stack: [ ret adr ] <-- rsp
  //        [ lo(arg) ]
  //        [ hi(arg) ]
  //
  if (kind == Interpreter::java_lang_math_fmaD) {
    __ movdbl(xmm2, Address(rsp, 5 * wordSize));
    __ movdbl(xmm1, Address(rsp, 3 * wordSize));
    __ movdbl(xmm0, Address(rsp, 1 * wordSize));
    __ fmad(xmm0, xmm1, xmm2, xmm0);
    __ pop(rdi);                               // get return address
    __ mov(rsp, rsi);                          // set sp to sender sp
    __ jmp(rdi);

    return entry_point;
  } else if (kind == Interpreter::java_lang_math_fmaF) {
    __ movflt(xmm2, Address(rsp, 3 * wordSize));
    __ movflt(xmm1, Address(rsp, 2 * wordSize));
    __ movflt(xmm0, Address(rsp, 1 * wordSize));
    __ fmaf(xmm0, xmm1, xmm2, xmm0);
    __ pop(rdi);                               // get return address
    __ mov(rsp, rsi);                          // set sp to sender sp
    __ jmp(rdi);

    return entry_point;
 }

  __ fld_d(Address(rsp, 1*wordSize));
  switch (kind) {
    case Interpreter::java_lang_math_sin :
        __ subptr(rsp, 2 * wordSize);
        __ fstp_d(Address(rsp, 0));
        if (VM_Version::supports_sse2() && StubRoutines::dsin() != NULL) {
          __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, StubRoutines::dsin())));
        } else {
          __ call_VM_leaf0(CAST_FROM_FN_PTR(address, SharedRuntime::dsin));
        }
        __ addptr(rsp, 2 * wordSize);
        break;
    case Interpreter::java_lang_math_cos :
        __ subptr(rsp, 2 * wordSize);
        __ fstp_d(Address(rsp, 0));
        if (VM_Version::supports_sse2() && StubRoutines::dcos() != NULL) {
          __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, StubRoutines::dcos())));
        } else {
          __ call_VM_leaf0(CAST_FROM_FN_PTR(address, SharedRuntime::dcos));
        }
        __ addptr(rsp, 2 * wordSize);
        break;
    case Interpreter::java_lang_math_tan :
        __ subptr(rsp, 2 * wordSize);
        __ fstp_d(Address(rsp, 0));
        if (StubRoutines::dtan() != NULL) {
          __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, StubRoutines::dtan())));
        } else {
          __ call_VM_leaf0(CAST_FROM_FN_PTR(address, SharedRuntime::dtan));
        }
        __ addptr(rsp, 2 * wordSize);
        break;
    case Interpreter::java_lang_math_sqrt:
        __ fsqrt();
        break;
    case Interpreter::java_lang_math_abs:
        __ fabs();
        break;
    case Interpreter::java_lang_math_log:
        __ subptr(rsp, 2 * wordSize);
        __ fstp_d(Address(rsp, 0));
        if (StubRoutines::dlog() != NULL) {
          __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, StubRoutines::dlog())));
        } else {
          __ call_VM_leaf0(CAST_FROM_FN_PTR(address, SharedRuntime::dlog));
        }
        __ addptr(rsp, 2 * wordSize);
        break;
    case Interpreter::java_lang_math_log10:
        __ subptr(rsp, 2 * wordSize);
        __ fstp_d(Address(rsp, 0));
        if (StubRoutines::dlog10() != NULL) {
          __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, StubRoutines::dlog10())));
//.........這裏部分代碼省略.........

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;
    bool canOptimize = m_codeBlock->usesArguments()
                       && arguments == m_codeBlock->argumentsRegister()
                       && !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);
        add32(TrustedImm32(firstFreeRegister + JSStack::CallFrameHeaderSize), regT1);
        lshift32(TrustedImm32(3), regT1);
        addPtr(callFrameRegister, regT1);
        // regT1: newCallFrame

        slowCase.append(branchPtr(Below, AbsoluteAddress(m_vm->interpreter->stack().addressOfEnd()), 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.
        neg32(regT0);
        signExtend32ToPtr(regT0, regT0);
        end.append(branchAdd64(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))));
        branchAdd64(NonZero, TrustedImm32(1), regT0).linkTo(copyLoop, this);

        end.append(jump());
    }

    if (canOptimize)
        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 (canOptimize)
        end.link(this);
}

TObject *luaA_Address(lua_Object o) {
	return Address(o);
}

int32 lua_isnil(lua_Object o) {
	return (o == LUA_NOOBJECT) || (ttype(Address(o)) == LUA_T_NIL);
}

int32 lua_currentline(lua_Function func) {
	TObject *f = Address(func);
	return (f + 1 < lua_state->stack.top && (f + 1)->ttype == LUA_T_LINE) ? (f + 1)->value.i : -1;
}

int32 lua_istable(lua_Object o) {
	return (o != LUA_NOOBJECT) && (ttype(Address(o)) == LUA_T_ARRAY);
}