V8_WARN_UNUSED_RESULT MaybeHandle<Object> Invoke(Isolate* isolate,
                                                 const InvokeParams& params) {
  RCS_SCOPE(isolate, RuntimeCallCounterId::kInvoke);
  DCHECK(!IsJSGlobalObject(*params.receiver));
  DCHECK_LE(params.argc, FixedArray::kMaxLength);
  DCHECK(!isolate->has_exception());
  ...
  // Placeholder for return value.
  Tagged<Object> value;
  Handle<Code> code =
      JSEntry(isolate, params.execution_target, params.is_construct);
  {
    // Save and restore context around invocation and block the
    // allocation of handles without explicit handle scopes.
    SaveContext save(isolate);
    SealHandleScope shs(isolate);

    if (v8_flags.clear_exceptions_on_js_entry) isolate->clear_exception();

    if (params.execution_target == Execution::Target::kCallable) {
      // clang-format off
      // {new_target}, {target}, {receiver}, return value: tagged pointers
      // {argv}: pointer to array of tagged pointers
      using JSEntryFunction = GeneratedCode<Address(
          Address root_register_value, Address new_target, Address target,
          Address receiver, intptr_t argc, Address** argv)>;
      // clang-format on
      JSEntryFunction stub_entry =
          JSEntryFunction::FromAddress(isolate, code->instruction_start());

      Address orig_func = (*params.new_target).ptr();
      Address func = (*params.target).ptr();
      Address recv = (*params.receiver).ptr();
      Address** argv = reinterpret_cast<Address**>(params.argv);
      RCS_SCOPE(isolate, RuntimeCallCounterId::kJS_Execution);
      value = Tagged<Object>(
          stub_entry.Call(isolate->isolate_data()->isolate_root(), orig_func,
                          func, recv, JSParameterCount(params.argc), argv));
	...

Handle<Code> JSEntry(Isolate* isolate, Execution::Target execution_target,
                     bool is_construct) {
  if (is_construct) {
    DCHECK_EQ(Execution::Target::kCallable, execution_target);
    return BUILTIN_CODE(isolate, JSConstructEntry);
  } else if (execution_target == Execution::Target::kCallable) {
    DCHECK(!is_construct);
    return BUILTIN_CODE(isolate, JSEntry);
  } else if (execution_target == Execution::Target::kRunMicrotasks) {
    DCHECK(!is_construct);
    return BUILTIN_CODE(isolate, JSRunMicrotasksEntry);
  }
  UNREACHABLE();
}

void Builtins::Generate_JSEntry(MacroAssembler* masm) {
  Generate_JSEntryVariant(masm, StackFrame::ENTRY, Builtin::kJSEntryTrampoline);
}

void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
  Generate_JSEntryTrampolineHelper(masm, false);
}

static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                             bool is_construct) {
  // Expects six C++ function parameters.
  // - Address root_register_value
  // - Address new_target (tagged Object pointer)
  // - Address function (tagged JSFunction pointer)
  // - Address receiver (tagged Object pointer)
  // - intptr_t argc
  // - Address** argv (pointer to array of tagged Object pointers)
  // (see Handle::Invoke in execution.cc).

  // Open a C++ scope for the FrameScope.
  {
    // Platform specific argument handling. After this, the stack contains
    // an internal frame and the pushed function and receiver, and
    // register rax and rbx holds the argument count and argument array,
    // while rdi holds the function pointer, rsi the context, and rdx the
    // new.target.

    // MSVC parameters in:
    // rcx        : root_register_value
    // rdx        : new_target
    // r8         : function
    // r9         : receiver
    // [rsp+0x20] : argc
    // [rsp+0x28] : argv
    //
    // GCC parameters in:
    // rdi : root_register_value
    // rsi : new_target
    // rdx : function
    // rcx : receiver
    // r8  : argc
    // r9  : argv

    __ movq(rdi, kCArgRegs[2]);
    __ Move(rdx, kCArgRegs[1]);
    // rdi : function
    // rdx : new_target
  ...
    // Invoke the builtin code.
    Builtin builtin = is_construct ? Builtin::kConstruct : Builtins::Call();
    __ CallBuiltin(builtin);
    ...

void Builtins::Generate_Call_ReceiverIsAny(MacroAssembler* masm) {
  Generate_Call(masm, ConvertReceiverMode::kAny);
}

void Builtins::Generate_CallFunction_ReceiverIsAny(MacroAssembler* masm) {
  Generate_CallFunction(masm, ConvertReceiverMode::kAny);
}

// static
void Builtins::Generate_CallFunction(MacroAssembler* masm,
                                     ConvertReceiverMode mode) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments
  //  -- rdi : the function to call (checked to be a JSFunction)
  // ------
  ...
  __ movzxwq(
      rbx, FieldOperand(rdx, SharedFunctionInfo::kFormalParameterCountOffset));
  __ InvokeFunctionCode(rdi, no_reg, rbx, rax, InvokeType::kJump);
}

void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                        Register expected_parameter_count,
                                        Register actual_parameter_count,
                                        InvokeType type) {
  ...
  switch (type) {
    case InvokeType::kCall:
      CallJSFunction(function);
      break;
    case InvokeType::kJump:
      JumpJSFunction(function);
      break;
  }
  ...  

void MacroAssembler::CallJSFunction(Register function_object) {
  static_assert(kJavaScriptCallCodeStartRegister == rcx, "ABI mismatch");
#ifdef V8_ENABLE_SANDBOX
  // When the sandbox is enabled, we can directly fetch the entrypoint pointer
  // from the code pointer table instead of going through the Code object. In
  // this way, we avoid one memory load on this code path.
  LoadCodeEntrypointViaCodePointer(
      rcx, FieldOperand(function_object, JSFunction::kCodeOffset));
  call(rcx);
#else
  LoadTaggedField(rcx, FieldOperand(function_object, JSFunction::kCodeOffset));
  CallCodeObject(rcx);
#endif
}

void Builtins::Generate_InterpreterEntryTrampoline(
    MacroAssembler* masm, InterpreterEntryTrampolineMode mode) {
  Register closure = rdi;
  ...
  // Allocate the local and temporary register file on the stack.
  Label stack_overflow;
  {
    // Load frame size from the BytecodeArray object.
    __ movl(rcx, FieldOperand(kInterpreterBytecodeArrayRegister,
                              BytecodeArray::kFrameSizeOffset));

    // Do a stack check to ensure we don't go over the limit.
    __ movq(rax, rsp);
    __ subq(rax, rcx);
    __ cmpq(rax, __ StackLimitAsOperand(StackLimitKind::kRealStackLimit));
    __ j(below, &stack_overflow);

    // If ok, push undefined as the initial value for all register file entries.
    Label loop_header;
    Label loop_check;
    __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
    __ jmp(&loop_check, Label::kNear);
    __ bind(&loop_header);
    // TODO(rmcilroy): Consider doing more than one push per loop iteration.
    __ Push(kInterpreterAccumulatorRegister);
    // Continue loop if not done.
    __ bind(&loop_check);
    __ subq(rcx, Immediate(kSystemPointerSize));
    __ j(greater_equal, &loop_header, Label::kNear);
  }
  __ bind(&stack_overflow);
  __ CallRuntime(Runtime::kThrowStackOverflow);
  __ int3();  // Should not return.
}

Operand MacroAssembler::StackLimitAsOperand(StackLimitKind kind) {
  DCHECK(root_array_available());
  intptr_t offset = kind == StackLimitKind::kRealStackLimit
                        ? IsolateData::real_jslimit_offset()
                        : IsolateData::jslimit_offset();

  CHECK(is_int32(offset));
  return Operand(kRootRegister, static_cast<int32_t>(offset));
}

  static constexpr int real_jslimit_offset() {
    return stack_guard_offset() + StackGuard::real_jslimit_offset();
  }

#define V(Offset, Size, Name) \
  static constexpr int Name##_offset() { return Offset - kIsolateRootBias; }
  ISOLATE_DATA_FIELDS(V)
#undef V

  static constexpr int real_jslimit_offset() {
    return offsetof(StackGuard, thread_local_) +
           offsetof(ThreadLocal, real_jslimit_);
  }

void StackGuard::ThreadLocal::Initialize(Isolate* isolate,
                                         const ExecutionAccess& lock) {
  const uintptr_t kLimitSize = v8_flags.stack_size * KB;
  DCHECK_GT(GetCurrentStackPosition(), kLimitSize);
  uintptr_t limit = GetCurrentStackPosition() - kLimitSize;
  real_jslimit_ = SimulatorStack::JsLimitFromCLimit(isolate, limit);
  set_jslimit(SimulatorStack::JsLimitFromCLimit(isolate, limit));
  real_climit_ = limit;
  set_climit(limit);
  interrupt_scopes_ = nullptr;
  interrupt_flags_ = 0;
}