[builtins] TurboFan version of Array.prototype.forEach including fast path for FAST_ELEMENTS

src/bootstrapper.cc

 // Copyright 2014 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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/ieee754.h"
 #include "src/code-stubs.h"
@@ skipping 199 matching lines @@
   void ConfigureUtilsObject(GlobalContextType context_type);
 
 #define DECLARE_FEATURE_INITIALIZATION(id, descr) \
   void InitializeGlobal_##id();
 
   HARMONY_INPROGRESS(DECLARE_FEATURE_INITIALIZATION)
   HARMONY_STAGED(DECLARE_FEATURE_INITIALIZATION)
   HARMONY_SHIPPING(DECLARE_FEATURE_INITIALIZATION)
 #undef DECLARE_FEATURE_INITIALIZATION
 
+  void InitializeGlobal_enable_fast_array_builtins();
+
   Handle<JSFunction> InstallArrayBuffer(Handle<JSObject> target,
                                         const char* name, Builtins::Name call,
                                         BuiltinFunctionId id);
   Handle<JSFunction> InstallInternalArray(Handle<JSObject> target,
                                           const char* name,
                                           ElementsKind elements_kind);
   bool InstallNatives(GlobalContextType context_type);
 
   void InstallTypedArray(const char* name, ElementsKind elements_kind,
                          Handle<JSFunction>* fun);
@@ skipping 2674 matching lines @@
 }
 
 
 void Genesis::InitializeExperimentalGlobal() {
 #define FEATURE_INITIALIZE_GLOBAL(id, descr) InitializeGlobal_##id();
 
   HARMONY_INPROGRESS(FEATURE_INITIALIZE_GLOBAL)
   HARMONY_STAGED(FEATURE_INITIALIZE_GLOBAL)
   HARMONY_SHIPPING(FEATURE_INITIALIZE_GLOBAL)
 #undef FEATURE_INITIALIZE_GLOBAL
+
+  InitializeGlobal_enable_fast_array_builtins();
 }
 
 
 bool Bootstrapper::CompileBuiltin(Isolate* isolate, int index) {
   Vector<const char> name = Natives::GetScriptName(index);
   Handle<String> source_code =
       isolate->bootstrapper()->SourceLookup<Natives>(index);
 
   // We pass in extras_utils so that builtin code can set it up for later use
   // by actual extras code, compiled with CompileExtraBuiltin.
@@ skipping 609 matching lines @@
       JSGlobalObject::cast(native_context->global_object()));
   Handle<String> symbol_string = factory->InternalizeUtf8String("Symbol");
   Handle<JSObject> symbol = Handle<JSObject>::cast(
       JSObject::GetProperty(global, symbol_string).ToHandleChecked());
   Handle<String> name_string = factory->InternalizeUtf8String(name);
   PropertyAttributes attributes =
       static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE | READ_ONLY);
   JSObject::AddProperty(symbol, name_string, value, attributes);
 }
 
+void Genesis::InitializeGlobal_enable_fast_array_builtins() {
+  if (!FLAG_enable_fast_array_builtins) return;
+
+  Handle<JSGlobalObject> global(native_context()->global_object());
+  Isolate* isolate = global->GetIsolate();
+  Factory* factory = isolate->factory();
+
+  Handle<JSObject> utils =
+      Handle<JSObject>::cast(isolate->natives_utils_object());

[Yang, 2017/02/03 10:20:25]

Alternatively, you could just get global.Array.prototype.forEach, and won't have
to touch the utils object at all.

[danno, 2017/02/03 12:46:55]

Done.

+  LookupIterator it(utils,
+                    factory->NewStringFromAsciiChecked("ForEachFunction"),
+                    LookupIterator::OWN_SKIP_INTERCEPTOR);
+  Handle<Object> for_each_function = Object::GetProperty(&it).ToHandleChecked();
+  Handle<JSFunction>::cast(for_each_function)
+      ->set_code(isolate->builtins()->builtin(Builtins::kArrayForEach));
+}
 
 void Genesis::InitializeGlobal_harmony_sharedarraybuffer() {
   if (!FLAG_harmony_sharedarraybuffer) return;
 
   Handle<JSGlobalObject> global(native_context()->global_object());
   Isolate* isolate = global->GetIsolate();
   Factory* factory = isolate->factory();
 
   Handle<JSFunction> shared_array_buffer_fun =
       InstallArrayBuffer(global, "SharedArrayBuffer",
@@ skipping 1291 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8