Turn Function.prototype.bind into a hydrogen stub optimized for the common case

src/builtins.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/builtins.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/base/once.h"
@@ skipping 4220 matching lines @@
 
 // ES6 section 19.2.1.1 Function ( p1, p2, ... , pn, body )
 BUILTIN(FunctionConstructor) {
   HandleScope scope(isolate);
   Handle<JSFunction> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result, CreateDynamicFunction(isolate, args, "function"));
   return *result;
 }
 
+namespace {
 
-// ES6 section 19.2.3.2 Function.prototype.bind ( thisArg, ...args )
-BUILTIN(FunctionPrototypeBind) {
+Object* DoFunctionBind(Isolate* isolate,
+                       BuiltinArguments<BuiltinExtraArguments::kNone> args) {
   HandleScope scope(isolate);
   DCHECK_LE(1, args.length());
   if (!args.receiver()->IsCallable()) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewTypeError(MessageTemplate::kFunctionBind));
   }
 
   // Allocate the bound function with the given {this_arg} and {args}.
   Handle<JSReceiver> target = args.at<JSReceiver>(0);
   Handle<Object> this_arg = isolate->factory()->undefined_value();
@@ skipping 63 matching lines @@
     }
     LookupIterator it(function, isolate->factory()->name_string());
     DCHECK_EQ(LookupIterator::ACCESSOR, it.state());
     RETURN_FAILURE_ON_EXCEPTION(isolate,
                                 JSObject::DefineOwnPropertyIgnoreAttributes(
                                     &it, name, it.property_attributes()));
   }
   return *function;
 }
 
+}  // namespace
+
+// ES6 section 19.2.3.2 Function.prototype.bind ( thisArg, ...args )
+BUILTIN(FunctionPrototypeBind) { return DoFunctionBind(isolate, args); }
+
+// TODO(verwaest): This is a temporary helper until the FastFunctionBind stub
+// can

[Igor Sheludko, 2016/06/07 16:24:34]

Please fix comment wrapping.

+// tailcall to the builtin directly.
+RUNTIME_FUNCTION(Runtime_FunctionBind) {
+  DCHECK_EQ(2, args.length());
+  Arguments* incoming = reinterpret_cast<Arguments*>(args[0]);
+  // Rewrap the arguments as builtins arguments.
+  BuiltinArguments<BuiltinExtraArguments::kNone> caller_args(
+      incoming->length() + 1, incoming->arguments() + 1);
+  return DoFunctionBind(isolate, caller_args);
+}
+
 // ES6 section 19.2.3.5 Function.prototype.toString ( )
 BUILTIN(FunctionPrototypeToString) {
   HandleScope scope(isolate);
   Handle<Object> receiver = args.receiver();
   if (receiver->IsJSBoundFunction()) {
     return *JSBoundFunction::ToString(Handle<JSBoundFunction>::cast(receiver));
   } else if (receiver->IsJSFunction()) {
     return *JSFunction::ToString(Handle<JSFunction>::cast(receiver));
   }
   THROW_NEW_ERROR_RETURN_FAILURE(
@@ skipping 1470 matching lines @@
 BUILTIN_LIST_T(DEFINE_BUILTIN_ACCESSOR_T)
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 #undef DEFINE_BUILTIN_ACCESSOR_T
 #undef DEFINE_BUILTIN_ACCESSOR_H
 
 }  // namespace internal
 }  // namespace v8