Rework CallApi*Stubs.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 3dd2f45cbcc15c7fe858bbe870a582a98fa49c30..c63bd860467186d026d18b004f48a4ee02aa8575 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -5429,10 +5429,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ jmp(&leave_exit_frame);
 }
 
-static void CallApiFunctionStubHelper(MacroAssembler* masm,
-                                      const ParameterCount& argc,
-                                      bool return_first_arg,
-                                      bool call_data_undefined, bool is_lazy) {
+void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rdi                 : callee
   //  -- rbx                 : call_data
@@ -5465,8 +5462,6 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   STATIC_ASSERT(FCA::kHolderIndex == 0);
   STATIC_ASSERT(FCA::kArgsLength == 7);
 
-  DCHECK(argc.is_immediate() || rax.is(argc.reg()));
-
   __ PopReturnAddressTo(return_address);
 
   // context save
@@ -5478,7 +5473,7 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   // call data
   __ Push(call_data);
   Register scratch = call_data;
-  if (!call_data_undefined) {
+  if (!this->call_data_undefined()) {
     __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   }
   // return value
@@ -5495,7 +5490,7 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   // Push return address back on stack.
   __ PushReturnAddressFrom(return_address);
 
-  if (!is_lazy) {
+  if (!this->is_lazy()) {
     // load context from callee
     __ movp(context, FieldOperand(callee, JSFunction::kContextOffset));
   }
@@ -5507,28 +5502,15 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   PrepareCallApiFunction(masm, kApiStackSpace);
 
   // FunctionCallbackInfo::implicit_args_.
+  int argc = this->argc();
   __ movp(StackSpaceOperand(0), scratch);
-  if (argc.is_immediate()) {
-    __ addp(scratch, Immediate((argc.immediate() + FCA::kArgsLength - 1) *
-                               kPointerSize));
-    // FunctionCallbackInfo::values_.
-    __ movp(StackSpaceOperand(1), scratch);
-    // FunctionCallbackInfo::length_.
-    __ Set(StackSpaceOperand(2), argc.immediate());
-    // FunctionCallbackInfo::is_construct_call_.
-    __ Set(StackSpaceOperand(3), 0);
-  } else {
-    __ leap(scratch, Operand(scratch, argc.reg(), times_pointer_size,
-                             (FCA::kArgsLength - 1) * kPointerSize));
-    // FunctionCallbackInfo::values_.
-    __ movp(StackSpaceOperand(1), scratch);
-    // FunctionCallbackInfo::length_.
-    __ movp(StackSpaceOperand(2), argc.reg());
-    // FunctionCallbackInfo::is_construct_call_.
-    __ leap(argc.reg(), Operand(argc.reg(), times_pointer_size,
-                                (FCA::kArgsLength + 1) * kPointerSize));
-    __ movp(StackSpaceOperand(3), argc.reg());
-  }
+  __ addp(scratch, Immediate((argc + FCA::kArgsLength - 1) * kPointerSize));
+  // FunctionCallbackInfo::values_.
+  __ movp(StackSpaceOperand(1), scratch);
+  // FunctionCallbackInfo::length_.
+  __ Set(StackSpaceOperand(2), argc);
+  // FunctionCallbackInfo::is_construct_call_.
+  __ Set(StackSpaceOperand(3), 0);
 
 #if defined(__MINGW64__) || defined(_WIN64)
   Register arguments_arg = rcx;
@@ -5555,36 +5537,17 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
       FCA::kArgsLength - FCA::kContextSaveIndex);
   Operand is_construct_call_operand = StackSpaceOperand(3);
   Operand return_value_operand = args_from_rbp.GetArgumentOperand(
-      return_first_arg ? 0 : FCA::kArgsLength - FCA::kReturnValueOffset);
+      this->is_store() ? 0 : FCA::kArgsLength - FCA::kReturnValueOffset);
   int stack_space = 0;
   Operand* stack_space_operand = &is_construct_call_operand;
-  if (argc.is_immediate()) {
-    stack_space = argc.immediate() + FCA::kArgsLength + 1;
-    stack_space_operand = nullptr;
-  }
+  stack_space = argc + FCA::kArgsLength + 1;
+  stack_space_operand = nullptr;
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref, callback_arg,
                            stack_space, stack_space_operand,
                            return_value_operand, &context_restore_operand);
 }
 
 
-void CallApiFunctionStub::Generate(MacroAssembler* masm) {
-  bool call_data_undefined = this->call_data_undefined();
-  CallApiFunctionStubHelper(masm, ParameterCount(rax), false,
-                            call_data_undefined, false);
-}
-
-
-void CallApiAccessorStub::Generate(MacroAssembler* masm) {
-  bool is_store = this->is_store();
-  int argc = this->argc();
-  bool call_data_undefined = this->call_data_undefined();
-  bool is_lazy = this->is_lazy();
-  CallApiFunctionStubHelper(masm, ParameterCount(argc), is_store,
-                            call_data_undefined, is_lazy);
-}
-
-
 void CallApiGetterStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rsp[0]                          : return address