Revert of 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 589a594c150c342377f5317cc686f6a6f92cd9c1..b7923a7fbc6248332140def34eafbad7955f0de3 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -5396,7 +5396,10 @@
   __ jmp(&leave_exit_frame);
 }
 
-void CallApiCallbackStub::Generate(MacroAssembler* masm) {
+static void CallApiFunctionStubHelper(MacroAssembler* masm,
+                                      const ParameterCount& argc,
+                                      bool return_first_arg,
+                                      bool call_data_undefined, bool is_lazy) {
   // ----------- S t a t e -------------
   //  -- rdi                 : callee
   //  -- rbx                 : call_data
@@ -5429,6 +5432,8 @@
   STATIC_ASSERT(FCA::kHolderIndex == 0);
   STATIC_ASSERT(FCA::kArgsLength == 7);
 
+  DCHECK(argc.is_immediate() || rax.is(argc.reg()));
+
   __ PopReturnAddressTo(return_address);
 
   // context save
@@ -5440,7 +5445,7 @@
   // call data
   __ Push(call_data);
   Register scratch = call_data;
-  if (!this->call_data_undefined()) {
+  if (!call_data_undefined) {
     __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   }
   // return value
@@ -5457,7 +5462,7 @@
   // Push return address back on stack.
   __ PushReturnAddressFrom(return_address);
 
-  if (!this->is_lazy()) {
+  if (!is_lazy) {
     // load context from callee
     __ movp(context, FieldOperand(callee, JSFunction::kContextOffset));
   }
@@ -5469,15 +5474,28 @@
   PrepareCallApiFunction(masm, kApiStackSpace);
 
   // FunctionCallbackInfo::implicit_args_.
-  int argc = this->argc();
   __ movp(StackSpaceOperand(0), scratch);
-  __ 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 (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());
+  }
 
 #if defined(__MINGW64__) || defined(_WIN64)
   Register arguments_arg = rcx;
@@ -5504,14 +5522,33 @@
       FCA::kArgsLength - FCA::kContextSaveIndex);
   Operand is_construct_call_operand = StackSpaceOperand(3);
   Operand return_value_operand = args_from_rbp.GetArgumentOperand(
-      this->is_store() ? 0 : FCA::kArgsLength - FCA::kReturnValueOffset);
+      return_first_arg ? 0 : FCA::kArgsLength - FCA::kReturnValueOffset);
   int stack_space = 0;
   Operand* stack_space_operand = &is_construct_call_operand;
-  stack_space = argc + FCA::kArgsLength + 1;
-  stack_space_operand = nullptr;
+  if (argc.is_immediate()) {
+    stack_space = argc.immediate() + 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);
 }