[stubs] Drop CallApiCallbackStub::call_data_undefined optimization.

The CallApiCallbackStub can avoid loading undefined in case the
call_data is already undefined, which doubles the number of versions of
the stub and adds unnecessary complexity (at the benefit of saving one
stupid load). The idea is to turn the CallApiCallbackStub into a single
builtin instead, which does the right thing, so this is the first step
towards that goal.

R=yangguo@chromium.org
BUG=v8:6304

Review-Url: https://codereview.chromium.org/2838143003
Cr-Commit-Position: refs/heads/master@{#44869}

src/arm/code-stubs-arm.cc

@@ -2799,9 +2799,7 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   __ push(call_data);
 
   Register scratch = call_data;
-  if (!call_data_undefined()) {
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
-  }
+  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   // return value
   __ push(scratch);
   // return value default

src/arm64/code-stubs-arm64.cc

@@ -3031,9 +3031,7 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
     __ Ldr(context, FieldMemOperand(callee, JSFunction::kContextOffset));
   }
 
-  if (!call_data_undefined()) {
-    __ LoadRoot(call_data, Heap::kUndefinedValueRootIndex);
-  }
+  __ LoadRoot(call_data, Heap::kUndefinedValueRootIndex);
   Register isolate_reg = x5;
   __ Mov(isolate_reg, ExternalReference::isolate_address(masm->isolate()));
 

src/code-stubs.h

@@ -827,39 +827,29 @@ class CallApiCallbackStub : public PlatformCodeStub {
   static const int kArgMax = (1 << kArgBits) - 1;
 
   // CallApiCallbackStub for regular setters and getters.
-  CallApiCallbackStub(Isolate* isolate, bool is_store, bool call_data_undefined,
-                      bool is_lazy)
-      : CallApiCallbackStub(isolate, is_store ? 1 : 0, is_store,
-                            call_data_undefined, is_lazy) {}
+  CallApiCallbackStub(Isolate* isolate, bool is_store, bool is_lazy)
+      : CallApiCallbackStub(isolate, is_store ? 1 : 0, is_store, is_lazy) {}
 
   // CallApiCallbackStub for callback functions.
-  CallApiCallbackStub(Isolate* isolate, int argc, bool call_data_undefined,
-                      bool is_lazy)
-      : CallApiCallbackStub(isolate, argc, false, call_data_undefined,
-                            is_lazy) {}
+  CallApiCallbackStub(Isolate* isolate, int argc, bool is_lazy)
+      : CallApiCallbackStub(isolate, argc, false, is_lazy) {}
 
  private:
-  CallApiCallbackStub(Isolate* isolate, int argc, bool is_store,
-                      bool call_data_undefined, bool is_lazy)
+  CallApiCallbackStub(Isolate* isolate, int argc, bool is_store, bool is_lazy)
       : PlatformCodeStub(isolate) {
     CHECK(0 <= argc && argc <= kArgMax);
     minor_key_ = IsStoreBits::encode(is_store) |
-                 CallDataUndefinedBits::encode(call_data_undefined) |
                  ArgumentBits::encode(argc) |
                  IsLazyAccessorBits::encode(is_lazy);
   }
 
   bool is_store() const { return IsStoreBits::decode(minor_key_); }
   bool is_lazy() const { return IsLazyAccessorBits::decode(minor_key_); }
-  bool call_data_undefined() const {
-    return CallDataUndefinedBits::decode(minor_key_);
-  }
   int argc() const { return ArgumentBits::decode(minor_key_); }
 
   class IsStoreBits: public BitField<bool, 0, 1> {};
-  class CallDataUndefinedBits: public BitField<bool, 1, 1> {};
+  class IsLazyAccessorBits : public BitField<bool, 1, 1> {};
   class ArgumentBits : public BitField<int, 2, kArgBits> {};
-  class IsLazyAccessorBits : public BitField<bool, 3 + kArgBits, 1> {};
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(ApiCallback);
   DEFINE_PLATFORM_CODE_STUB(CallApiCallback, PlatformCodeStub);

src/compiler/js-call-reducer.cc

@@ -439,7 +439,7 @@ Reduction JSCallReducer::ReduceCallApiFunction(
   // the receiver (which is implicitly counted by CallApiCallbackStub) from the
   // arguments count.
   int const argc = static_cast<int>(params.arity() - 2);
-  CallApiCallbackStub stub(isolate, argc, data->IsUndefined(isolate), false);
+  CallApiCallbackStub stub(isolate, argc, false);
   CallInterfaceDescriptor cid = stub.GetCallInterfaceDescriptor();
   CallDescriptor* call_descriptor = Linkage::GetStubCallDescriptor(
       isolate, zone, cid,

src/compiler/js-native-context-specialization.cc

@@ -2215,7 +2215,7 @@ JSNativeContextSpecialization::InlineApiCall(
   int const argc = value == nullptr ? 0 : 1;
   // The stub always expects the receiver as the first param on the stack.
   CallApiCallbackStub stub(
-      isolate(), argc, call_data_object->IsUndefined(isolate()),
+      isolate(), argc,
       true /* FunctionTemplateInfo doesn't have an associated context. */);
   CallInterfaceDescriptor call_interface_descriptor =
       stub.GetCallInterfaceDescriptor();

src/crankshaft/hydrogen.cc

@@ -9102,7 +9102,6 @@ bool HOptimizedGraphBuilder::TryInlineApiCall(
   }
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
   Handle<Object> call_data_obj(api_call_info->data(), isolate());
-  bool call_data_undefined = call_data_obj->IsUndefined(isolate());
   HValue* call_data = Add<HConstant>(call_data_obj);
   ApiFunction fun(v8::ToCData<Address>(api_call_info->callback()));
   ExternalReference ref = ExternalReference(&fun,
@@ -9116,7 +9115,7 @@ bool HOptimizedGraphBuilder::TryInlineApiCall(
   HInstruction* call = nullptr;
   CHECK(argc <= CallApiCallbackStub::kArgMax);
   if (!is_function) {
-    CallApiCallbackStub stub(isolate(), is_store, call_data_undefined,
+    CallApiCallbackStub stub(isolate(), is_store,
                              !optimization.is_constant_call());
     Handle<Code> code = stub.GetCode();
     HConstant* code_value = Add<HConstant>(code);
@@ -9124,7 +9123,7 @@ bool HOptimizedGraphBuilder::TryInlineApiCall(
         code_value, argc + 1, stub.GetCallInterfaceDescriptor(),
         Vector<HValue*>(op_vals, arraysize(op_vals)), syntactic_tail_call_mode);
   } else {
-    CallApiCallbackStub stub(isolate(), argc, call_data_undefined, false);
+    CallApiCallbackStub stub(isolate(), argc, false);
     Handle<Code> code = stub.GetCode();
     HConstant* code_value = Add<HConstant>(code);
     call = New<HCallWithDescriptor>(

src/ia32/code-stubs-ia32.cc

@@ -2780,23 +2780,16 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   // call data
   __ push(call_data);
 
-  Register scratch = call_data;
-  if (!call_data_undefined()) {
-    // return value
-    __ push(Immediate(masm->isolate()->factory()->undefined_value()));
-    // return value default
-    __ push(Immediate(masm->isolate()->factory()->undefined_value()));
-  } else {
-    // return value
-    __ push(scratch);
-    // return value default
-    __ push(scratch);
-  }
+  // return value
+  __ push(Immediate(masm->isolate()->factory()->undefined_value()));
+  // return value default
+  __ push(Immediate(masm->isolate()->factory()->undefined_value()));
   // isolate
   __ push(Immediate(reinterpret_cast<int>(masm->isolate())));
   // holder
   __ push(holder);
 
+  Register scratch = call_data;
   __ mov(scratch, esp);
 
   // push return address

src/ic/arm/handler-compiler-arm.cc

@@ -221,10 +221,8 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   Isolate* isolate = masm->isolate();
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
-  bool call_data_undefined = false;
   // Put call data in place.
   if (api_call_info->data()->IsUndefined(isolate)) {
-    call_data_undefined = true;
     __ LoadRoot(data, Heap::kUndefinedValueRootIndex);
   } else {
     if (optimization.is_constant_call()) {
@@ -249,8 +247,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
   __ mov(api_function_address, Operand(ref));
 
   // Jump to stub.
-  CallApiCallbackStub stub(isolate, is_store, call_data_undefined,
-                           !optimization.is_constant_call());
+  CallApiCallbackStub stub(isolate, is_store, !optimization.is_constant_call());
   __ TailCallStub(&stub);
 }
 

src/ic/arm64/handler-compiler-arm64.cc

@@ -156,10 +156,8 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   Isolate* isolate = masm->isolate();
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
-  bool call_data_undefined = false;
   // Put call data in place.
   if (api_call_info->data()->IsUndefined(isolate)) {
-    call_data_undefined = true;
     __ LoadRoot(data, Heap::kUndefinedValueRootIndex);
   } else {
     if (optimization.is_constant_call()) {
@@ -184,8 +182,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
   __ Mov(api_function_address, ref);
 
   // Jump to stub.
-  CallApiCallbackStub stub(isolate, is_store, call_data_undefined,
-                           !optimization.is_constant_call());
+  CallApiCallbackStub stub(isolate, is_store, !optimization.is_constant_call());
   __ TailCallStub(&stub);
 }
 

src/ic/ia32/handler-compiler-ia32.cc

@@ -161,10 +161,8 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   Isolate* isolate = masm->isolate();
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
-  bool call_data_undefined = false;
   // Put call data in place.
   if (api_call_info->data()->IsUndefined(isolate)) {
-    call_data_undefined = true;
     __ mov(data, Immediate(isolate->factory()->undefined_value()));
   } else {
     if (optimization.is_constant_call()) {
@@ -182,8 +180,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
   __ mov(api_function_address, Immediate(function_address));
 
   // Jump to stub.
-  CallApiCallbackStub stub(isolate, is_store, call_data_undefined,
-                           !optimization.is_constant_call());
+  CallApiCallbackStub stub(isolate, is_store, !optimization.is_constant_call());
   __ TailCallStub(&stub);
 }
 

src/ic/mips/handler-compiler-mips.cc

@@ -211,10 +211,8 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   Isolate* isolate = masm->isolate();
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
-  bool call_data_undefined = false;
   // Put call data in place.
   if (api_call_info->data()->IsUndefined(isolate)) {
-    call_data_undefined = true;
     __ LoadRoot(data, Heap::kUndefinedValueRootIndex);
   } else {
     if (optimization.is_constant_call()) {
@@ -238,8 +236,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
   __ li(api_function_address, Operand(ref));
 
   // Jump to stub.
-  CallApiCallbackStub stub(isolate, is_store, call_data_undefined,
-                           !optimization.is_constant_call());
+  CallApiCallbackStub stub(isolate, is_store, !optimization.is_constant_call());
   __ TailCallStub(&stub);
 }
 

src/ic/mips64/handler-compiler-mips64.cc

@@ -210,10 +210,8 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   Isolate* isolate = masm->isolate();
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
-  bool call_data_undefined = false;
   // Put call data in place.
   if (api_call_info->data()->IsUndefined(isolate)) {
-    call_data_undefined = true;
     __ LoadRoot(data, Heap::kUndefinedValueRootIndex);
   } else {
     if (optimization.is_constant_call()) {
@@ -237,8 +235,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
   __ li(api_function_address, Operand(ref));
 
   // Jump to stub.
-  CallApiCallbackStub stub(isolate, is_store, call_data_undefined,
-                           !optimization.is_constant_call());
+  CallApiCallbackStub stub(isolate, is_store, !optimization.is_constant_call());
   __ TailCallStub(&stub);
 }
 

src/ic/x64/handler-compiler-x64.cc

@@ -139,10 +139,8 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   Isolate* isolate = masm->isolate();
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
-  bool call_data_undefined = false;
   // Put call data in place.
   if (api_call_info->data()->IsUndefined(isolate)) {
-    call_data_undefined = true;
     __ LoadRoot(data, Heap::kUndefinedValueRootIndex);
   } else {
     if (optimization.is_constant_call()) {
@@ -164,8 +162,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
           RelocInfo::EXTERNAL_REFERENCE);
 
   // Jump to stub.
-  CallApiCallbackStub stub(isolate, is_store, call_data_undefined,
-                           !optimization.is_constant_call());
+  CallApiCallbackStub stub(isolate, is_store, !optimization.is_constant_call());
   __ TailCallStub(&stub);
 }
 

src/mips/code-stubs-mips.cc

@@ -2973,9 +2973,7 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   }
 
   Register scratch = call_data;
-  if (!call_data_undefined()) {
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
-  }
+  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   // Push return value and default return value.
   __ Push(scratch, scratch);
   __ li(scratch, Operand(ExternalReference::isolate_address(masm->isolate())));

src/mips64/code-stubs-mips64.cc

@@ -2976,9 +2976,7 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   }
 
   Register scratch = call_data;
-  if (!call_data_undefined()) {
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
-  }
+  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   // Push return value and default return value.
   __ Push(scratch, scratch);
   __ li(scratch, Operand(ExternalReference::isolate_address(masm->isolate())));

src/x64/code-stubs-x64.cc

@@ -2743,15 +2743,13 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
 
   // call data
   __ Push(call_data);
-  Register scratch = call_data;
-  if (!this->call_data_undefined()) {
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
-  }
+
   // return value
-  __ Push(scratch);
+  __ PushRoot(Heap::kUndefinedValueRootIndex);
   // return value default
-  __ Push(scratch);
+  __ PushRoot(Heap::kUndefinedValueRootIndex);
   // isolate
+  Register scratch = call_data;
   __ Move(scratch, ExternalReference::isolate_address(masm->isolate()));
   __ Push(scratch);
   // holder