Turn Array.isArray into a Turbofan stub

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 333 matching lines @@
 
 
 BUILTIN(Illegal) {
   UNREACHABLE();
   return isolate->heap()->undefined_value();  // Make compiler happy.
 }
 
 
 BUILTIN(EmptyFunction) { return isolate->heap()->undefined_value(); }
 
+void Builtins::Generate_ArrayIsArray(CodeStubAssembler* assembler) {
+  typedef compiler::Node Node;
+  typedef CodeStubAssembler::Label Label;
+
+  Node* object = assembler->Parameter(1);
+  Node* context = assembler->Parameter(4);
+
+  Label call_runtime(assembler), return_true(assembler),
+      return_false(assembler);
+
+  assembler->GotoIf(assembler->WordIsSmi(object), &return_false);
+  Node* instance_type = assembler->LoadInstanceType(object);
+
+  assembler->GotoIf(assembler->Word32Equal(
+                        instance_type, assembler->Int32Constant(JS_ARRAY_TYPE)),
+                    &return_true);
+
+  // TODO(verwaest): Handle proxies in-place.
+  assembler->Branch(assembler->Word32Equal(
+                        instance_type, assembler->Int32Constant(JS_PROXY_TYPE)),
+                    &call_runtime, &return_false);
+
+  assembler->Bind(&return_true);
+  assembler->Return(assembler->BooleanConstant(true));
+
+  assembler->Bind(&return_false);
+  assembler->Return(assembler->BooleanConstant(false));
+
+  assembler->Bind(&call_runtime);
+  assembler->Return(
+      assembler->CallRuntime(Runtime::kArrayIsArray, context, object));
+}
+
 void Builtins::Generate_ObjectHasOwnProperty(CodeStubAssembler* assembler) {
   typedef compiler::Node Node;
   typedef CodeStubAssembler::Label Label;
   typedef CodeStubAssembler::Variable Variable;
 
   Node* object = assembler->Parameter(0);
   Node* key = assembler->Parameter(1);
   Node* context = assembler->Parameter(4);
 
   Label call_runtime(assembler), return_true(assembler),
@@ skipping 1238 matching lines @@
   if (*species == isolate->context()->native_context()->array_function()) {
     if (Fast_ArrayConcat(isolate, &args).ToHandle(&result_array)) {
       return *result_array;
     }
     if (isolate->has_pending_exception()) return isolate->heap()->exception();
   }
   return Slow_ArrayConcat(&args, species, isolate);
 }
 
 
-// ES6 22.1.2.2 Array.isArray
-BUILTIN(ArrayIsArray) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-  Handle<Object> object = args.at<Object>(1);
-  Maybe<bool> result = Object::IsArray(object);
-  MAYBE_RETURN(result, isolate->heap()->exception());
-  return *isolate->factory()->ToBoolean(result.FromJust());
-}
-
 namespace {
 
 MUST_USE_RESULT Maybe<bool> FastAssign(Handle<JSReceiver> to,
                                        Handle<Object> next_source) {
   // Non-empty strings are the only non-JSReceivers that need to be handled
   // explicitly by Object.assign.
   if (!next_source->IsJSReceiver()) {
     return Just(!next_source->IsString() ||
                 String::cast(*next_source)->length() == 0);
   }
@@ skipping 3762 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