Rework CallApi*Stubs.

src/s390/code-stubs-s390.cc

Index: src/s390/code-stubs-s390.cc
diff --git a/src/s390/code-stubs-s390.cc b/src/s390/code-stubs-s390.cc
index 10c9a01c311c86faa39c7385908fb564b8b930a1..9a570ffaf5d14ac1b1d980e8517c31b0c6871c28 100644
--- a/src/s390/code-stubs-s390.cc
+++ b/src/s390/code-stubs-s390.cc
@@ -5543,16 +5543,12 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ b(&leave_exit_frame, Label::kNear);
 }
 
-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 -------------
   //  -- r2                  : callee
   //  -- r6                  : call_data
   //  -- r4                  : holder
   //  -- r3                  : api_function_address
-  //  -- r5                  : number of arguments if argc is a register
   //  -- cp                  : context
   //  --
   //  -- sp[0]               : last argument
@@ -5578,8 +5574,6 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   STATIC_ASSERT(FCA::kHolderIndex == 0);
   STATIC_ASSERT(FCA::kArgsLength == 7);
 
-  DCHECK(argc.is_immediate() || r2.is(argc.reg()));
-
   // context save
   __ push(context);
   if (!is_lazy) {
@@ -5594,7 +5588,7 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   __ push(call_data);
 
   Register scratch = call_data;
-  if (!call_data_undefined) {
+  if (!call_data_undefined()) {
     __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   }
   // return value
@@ -5630,28 +5624,15 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   __ AddP(r2, sp, Operand(kFunctionCallbackInfoOffset));
   // FunctionCallbackInfo::implicit_args_
   __ StoreP(scratch, MemOperand(r2, 0 * kPointerSize));
-  if (argc.is_immediate()) {
-    // FunctionCallbackInfo::values_
-    __ AddP(ip, scratch,
-            Operand((FCA::kArgsLength - 1 + argc.immediate()) * kPointerSize));
-    __ StoreP(ip, MemOperand(r2, 1 * kPointerSize));
-    // FunctionCallbackInfo::length_ = argc
-    __ LoadImmP(ip, Operand(argc.immediate()));
-    __ StoreW(ip, MemOperand(r2, 2 * kPointerSize));
-    // FunctionCallbackInfo::is_construct_call_ = 0
-    __ LoadImmP(ip, Operand::Zero());
-    __ StoreW(ip, MemOperand(r2, 2 * kPointerSize + kIntSize));
-  } else {
-    __ ShiftLeftP(ip, argc.reg(), Operand(kPointerSizeLog2));
-    __ AddP(ip, ip, Operand((FCA::kArgsLength - 1) * kPointerSize));
-    // FunctionCallbackInfo::values_
-    __ AddP(r0, scratch, ip);
-    __ StoreP(r0, MemOperand(r2, 1 * kPointerSize));
-    // FunctionCallbackInfo::length_ = argc
-    __ StoreW(argc.reg(), MemOperand(r2, 2 * kPointerSize));
-    // FunctionCallbackInfo::is_construct_call_
-    __ StoreW(ip, MemOperand(r2, 2 * kPointerSize + kIntSize));
-  }
+  // FunctionCallbackInfo::values_
+  __ AddP(ip, scratch, Operand((FCA::kArgsLength - 1 + argc()) * kPointerSize));
+  __ StoreP(ip, MemOperand(r2, 1 * kPointerSize));
+  // FunctionCallbackInfo::length_ = argc
+  __ LoadImmP(ip, Operand(argc()));
+  __ StoreW(ip, MemOperand(r2, 2 * kPointerSize));
+  // FunctionCallbackInfo::is_construct_call_ = 0
+  __ LoadImmP(ip, Operand::Zero());
+  __ StoreW(ip, MemOperand(r2, 2 * kPointerSize + kIntSize));
 
   ExternalReference thunk_ref =
       ExternalReference::invoke_function_callback(masm->isolate());
@@ -5661,7 +5642,7 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
       fp, (2 + FCA::kContextSaveIndex) * kPointerSize);
   // Stores return the first js argument
   int return_value_offset = 0;
-  if (return_first_arg) {
+  if (is_store()) {
     return_value_offset = 2 + FCA::kArgsLength;
   } else {
     return_value_offset = 2 + FCA::kReturnValueOffset;
@@ -5671,30 +5652,13 @@ static void CallApiFunctionStubHelper(MacroAssembler* masm,
   MemOperand is_construct_call_operand =
       MemOperand(sp, kFunctionCallbackInfoOffset + 2 * kPointerSize + kIntSize);
   MemOperand* stack_space_operand = &is_construct_call_operand;
-  if (argc.is_immediate()) {
-    stack_space = argc.immediate() + FCA::kArgsLength + 1;
-    stack_space_operand = NULL;
-  }
+  stack_space = argc() + FCA::kArgsLength + 1;
+  stack_space_operand = NULL;
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref, 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(r6), 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 -------------
   //  -- sp[0]                        : name