split api call stubs into accessor and function call stubs

src/arm64/code-stubs-arm64.cc

Index: src/arm64/code-stubs-arm64.cc
diff --git a/src/arm64/code-stubs-arm64.cc b/src/arm64/code-stubs-arm64.cc
index e773b531a1e2784ca34a05626728621c5fd4adc2..fa450d75e2566c03423ca38db54b4f1cbab81f59 100644
--- a/src/arm64/code-stubs-arm64.cc
+++ b/src/arm64/code-stubs-arm64.cc
@@ -5043,12 +5043,16 @@ void InternalArrayConstructorStub::Generate(MacroAssembler* masm) {
 }
 
 
-void CallApiFunctionStub::Generate(MacroAssembler* masm) {
+static void CallApiFunctionStubHelper(MacroAssembler* masm,
+                                      const ParameterCount& argc,
+                                      bool return_first_arg,
+                                      bool call_data_undefined) {
   // ----------- S t a t e -------------
   //  -- x0                  : callee
   //  -- x4                  : call_data
   //  -- x2                  : holder
   //  -- x1                  : api_function_address
+  //  -- x3                  : number of arguments if argc is a register
   //  -- cp                  : context
   //  --
   //  -- sp[0]               : last argument
@@ -5063,10 +5067,6 @@ void CallApiFunctionStub::Generate(MacroAssembler* masm) {
   Register api_function_address = x1;
   Register context = cp;
 
-  int argc = this->argc();
-  bool is_store = this->is_store();
-  bool call_data_undefined = this->call_data_undefined();
-
   typedef FunctionCallbackArguments FCA;
 
   STATIC_ASSERT(FCA::kContextSaveIndex == 6);
@@ -5078,6 +5078,8 @@ void CallApiFunctionStub::Generate(MacroAssembler* masm) {
   STATIC_ASSERT(FCA::kHolderIndex == 0);
   STATIC_ASSERT(FCA::kArgsLength == 7);
 
+  DCHECK(argc.is_immediate() || x3.is(argc.reg()));
+
   // FunctionCallbackArguments: context, callee and call data.
   __ Push(context, callee, call_data);
 
@@ -5088,7 +5090,7 @@ void CallApiFunctionStub::Generate(MacroAssembler* masm) {
     __ LoadRoot(call_data, Heap::kUndefinedValueRootIndex);
   }
   Register isolate_reg = x5;
-  __ Mov(isolate_reg, ExternalReference::isolate_address(isolate()));
+  __ Mov(isolate_reg, ExternalReference::isolate_address(masm->isolate()));
 
   // FunctionCallbackArguments:
   //    return value, return value default, isolate, holder.
@@ -5113,37 +5115,70 @@ void CallApiFunctionStub::Generate(MacroAssembler* masm) {
   // x0 = FunctionCallbackInfo&
   // Arguments is after the return address.
   __ Add(x0, masm->StackPointer(), 1 * kPointerSize);
-  // FunctionCallbackInfo::implicit_args_ and FunctionCallbackInfo::values_
-  __ Add(x10, args, Operand((FCA::kArgsLength - 1 + argc) * kPointerSize));
-  __ Stp(args, x10, MemOperand(x0, 0 * kPointerSize));
-  // FunctionCallbackInfo::length_ = argc and
-  // FunctionCallbackInfo::is_construct_call = 0
-  __ Mov(x10, argc);
-  __ Stp(x10, xzr, MemOperand(x0, 2 * kPointerSize));
-
-  const int kStackUnwindSpace = argc + FCA::kArgsLength + 1;
+  if (argc.is_immediate()) {
+    // FunctionCallbackInfo::implicit_args_ and FunctionCallbackInfo::values_
+    __ Add(x10, args,
+           Operand((FCA::kArgsLength - 1 + argc.immediate()) * kPointerSize));
+    __ Stp(args, x10, MemOperand(x0, 0 * kPointerSize));
+    // FunctionCallbackInfo::length_ = argc and
+    // FunctionCallbackInfo::is_construct_call = 0
+    __ Mov(x10, argc.immediate());
+    __ Stp(x10, xzr, MemOperand(x0, 2 * kPointerSize));
+  } else {
+    // FunctionCallbackInfo::implicit_args_ and FunctionCallbackInfo::values_
+    __ Add(x10, args, Operand(argc.reg(), LSL, kPointerSizeLog2));
+    __ Add(x10, x10, (FCA::kArgsLength - 1) * kPointerSize);
+    __ Stp(args, x10, MemOperand(x0, 0 * kPointerSize));
+    // FunctionCallbackInfo::length_ = argc and
+    // FunctionCallbackInfo::is_construct_call
+    __ Add(x10, argc.reg(), FCA::kArgsLength + 1);
+    __ Mov(x10, Operand(x10, LSL, kPointerSizeLog2));
+    __ Stp(argc.reg(), x10, MemOperand(x0, 2 * kPointerSize));
+  }
+
   ExternalReference thunk_ref =
-      ExternalReference::invoke_function_callback(isolate());
+      ExternalReference::invoke_function_callback(masm->isolate());
 
   AllowExternalCallThatCantCauseGC scope(masm);
   MemOperand context_restore_operand(
       fp, (2 + FCA::kContextSaveIndex) * kPointerSize);
   // Stores return the first js argument
   int return_value_offset = 0;
-  if (is_store) {
+  if (return_first_arg) {
     return_value_offset = 2 + FCA::kArgsLength;
   } else {
     return_value_offset = 2 + FCA::kReturnValueOffset;
   }
   MemOperand return_value_operand(fp, return_value_offset * kPointerSize);
+  int stack_space = 0;
+  MemOperand is_construct_call_operand =
+      MemOperand(masm->StackPointer(), 4 * kPointerSize);
+  MemOperand* stack_space_operand = &is_construct_call_operand;
+  if (argc.is_immediate()) {
+    stack_space = argc.immediate() + FCA::kArgsLength + 1;
+    stack_space_operand = NULL;
+  }
 
   const int spill_offset = 1 + kApiStackSpace;
-  __ CallApiFunctionAndReturn(api_function_address,
-                              thunk_ref,
-                              kStackUnwindSpace,
-                              spill_offset,
-                              return_value_operand,
-                              &context_restore_operand);
+  __ CallApiFunctionAndReturn(api_function_address, thunk_ref, stack_space,
+                              stack_space_operand, spill_offset,
+                              return_value_operand, &context_restore_operand);
+}
+
+
+void CallApiFunctionStub::Generate(MacroAssembler* masm) {
+  bool call_data_undefined = this->call_data_undefined();
+  CallApiFunctionStubHelper(masm, ParameterCount(x3), false,
+                            call_data_undefined);
+}
+
+
+void CallApiAccessorStub::Generate(MacroAssembler* masm) {
+  bool is_store = this->is_store();
+  int argc = is_store ? 1 : 0;
+  bool call_data_undefined = this->call_data_undefined();
+  CallApiFunctionStubHelper(masm, ParameterCount(argc), is_store,
+                            call_data_undefined);
 }
 
 
@@ -5181,12 +5216,9 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
       ExternalReference::invoke_accessor_getter_callback(isolate());
 
   const int spill_offset = 1 + kApiStackSpace;
-  __ CallApiFunctionAndReturn(api_function_address,
-                              thunk_ref,
-                              kStackUnwindSpace,
-                              spill_offset,
-                              MemOperand(fp, 6 * kPointerSize),
-                              NULL);
+  __ CallApiFunctionAndReturn(api_function_address, thunk_ref,
+                              kStackUnwindSpace, NULL, spill_offset,
+                              MemOperand(fp, 6 * kPointerSize), NULL);
 }