[stubs] Convert GrowElementsStub to TurboFan

src/code-stubs.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stubs.h"
 
 #include <sstream>
 
 #include "src/bootstrapper.h"
 #include "src/code-factory.h"
@@ skipping 4202 matching lines @@
   descriptor->Initialize(
       FUNCTION_ADDR(Runtime_BinaryOpIC_MissWithAllocationSite));
 }
 
 
 void StringAddStub::InitializeDescriptor(CodeStubDescriptor* descriptor) {
   descriptor->Initialize(Runtime::FunctionForId(Runtime::kStringAdd)->entry);
   descriptor->SetMissHandler(Runtime::kStringAdd);
 }
 
-
-void GrowArrayElementsStub::InitializeDescriptor(
-    CodeStubDescriptor* descriptor) {
-  descriptor->Initialize(
-      Runtime::FunctionForId(Runtime::kGrowArrayElements)->entry);
-}
-
-
 namespace {
 
 compiler::Node* GenerateHasProperty(
     CodeStubAssembler* assembler, compiler::Node* object, compiler::Node* key,
     compiler::Node* context, Runtime::FunctionId fallback_runtime_function_id) {
   typedef compiler::Node Node;
   typedef CodeStubAssembler::Label Label;
   typedef CodeStubAssembler::Variable Variable;
 
   Label call_runtime(assembler, Label::kDeferred), return_true(assembler),
@@ skipping 749 matching lines @@
     CodeStubAssembler* assembler) const {
   typedef compiler::Node Node;
   Node* function = assembler->Parameter(Descriptor::kFunction);
   Node* array_map = assembler->LoadObjectField(
       function, JSFunction::kPrototypeOrInitialMapOffset);
   SingleArgumentConstructorCommon<Descriptor>(
       assembler, elements_kind(), array_map, assembler->UndefinedConstant(),
       DONT_TRACK_ALLOCATION_SITE);
 }
 
+void GrowArrayElementsStub::GenerateAssembly(
+    CodeStubAssembler* assembler) const {
+  typedef compiler::Node Node;
+  CodeStubAssembler::Label runtime(assembler,
+                                   CodeStubAssembler::Label::kDeferred);
+
+  Node* object = assembler->Parameter(Descriptor::kObject);
+  Node* key = assembler->Parameter(Descriptor::kKey);
+  Node* context = assembler->Parameter(Descriptor::kContext);
+
+  ElementsKind kind = elements_kind();
+
+  Node* elements = assembler->LoadElements(object);
+  Node* current_capacity = assembler->LoadFixedArrayBaseLength(elements);
+
+  Node* new_elements = assembler->CheckAndGrowElementsCapacity(
+      context, object, elements, kind, current_capacity, key, &runtime);
+
+  assembler->StoreObjectField(object, JSObject::kElementsOffset, new_elements);
+
+  assembler->Return(new_elements);
+
+  assembler->Bind(&runtime);
+  // TODO(danno): Make this a tail call when the stub is only used from TurboFan

[Benedikt Meurer, 2016/08/05 04:35:21]

Ouch!

+  // code. This musn't be a tail call for now, since the caller site in lithium
+  // creates a safepoint. This safepoint musn't have a different number of
+  // arguments on the stack in the case that a GC happens from the slow-case
+  // allocation path (zero, since all the stubs inputs are in registers) and
+  // when the call happens (it would be two in the tail call case due to the
+  // tail call pushing the arguments on the stack for the runtime call). By not
+  // tail-calling, the runtime call case also has zero arguments on the stack
+  // for the stub frame.
+  assembler->Return(assembler->CallRuntime(Runtime::kGrowArrayElements, context,
+                                           object, key));
+}
+
 ArrayConstructorStub::ArrayConstructorStub(Isolate* isolate)
     : PlatformCodeStub(isolate) {
   minor_key_ = ArgumentCountBits::encode(ANY);
 }
 
-
 ArrayConstructorStub::ArrayConstructorStub(Isolate* isolate,
                                            int argument_count)
     : PlatformCodeStub(isolate) {
   if (argument_count == 0) {
     minor_key_ = ArgumentCountBits::encode(NONE);
   } else if (argument_count == 1) {
     minor_key_ = ArgumentCountBits::encode(ONE);
   } else if (argument_count >= 2) {
     minor_key_ = ArgumentCountBits::encode(MORE_THAN_ONE);
   } else {
@@ skipping 16 matching lines @@
   if (type->Is(Type::UntaggedPointer())) {
     return Representation::External();
   }
 
   DCHECK(!type->Is(Type::Untagged()));
   return Representation::Tagged();
 }
 
 }  // namespace internal
 }  // namespace v8