Split off remaining runtime functions in runtime.cc.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/638423003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24533 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUILD.gn

@@ -825,19 +825,23 @@ source_set("v8_base") {
     "src/rewriter.h",
     "src/runtime-profiler.cc",
     "src/runtime-profiler.h",
+    "src/runtime/runtime-api.cc",
+    "src/runtime/runtime-array.cc",
     "src/runtime/runtime-classes.cc",
     "src/runtime/runtime-collections.cc",
     "src/runtime/runtime-compiler.cc",
-    "src/runtime/runtime-i18n.cc",
     "src/runtime/runtime-date.cc",
     "src/runtime/runtime-debug.cc",
     "src/runtime/runtime-function.cc",
     "src/runtime/runtime-generator.cc",
+    "src/runtime/runtime-i18n.cc",
+    "src/runtime/runtime-internal.cc",
     "src/runtime/runtime-json.cc",
     "src/runtime/runtime-literals.cc",
     "src/runtime/runtime-liveedit.cc",
     "src/runtime/runtime-maths.cc",
     "src/runtime/runtime-numbers.cc",
+    "src/runtime/runtime-object.cc",
     "src/runtime/runtime-observe.cc",
     "src/runtime/runtime-proxy.cc",
     "src/runtime/runtime-regexp.cc",

src/macros.py

@@ -254,7 +254,7 @@ macro OVERRIDE_SUBJECT(override) = ((override)[(override).length - 1]);
 macro OVERRIDE_CAPTURE(override, index) = ((override)[(index)]);
 
 # PropertyDescriptor return value indices - must match
-# PropertyDescriptorIndices in runtime.cc.
+# PropertyDescriptorIndices in runtime-object.cc.
 const IS_ACCESSOR_INDEX = 0;
 const VALUE_INDEX = 1;
 const GETTER_INDEX = 2;

src/runtime/runtime-api.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/v8.h"
+
+#include "src/arguments.h"
+#include "src/bootstrapper.h"
+#include "src/runtime/runtime.h"
+#include "src/runtime/runtime-utils.h"
+
+namespace v8 {
+namespace internal {
+
+RUNTIME_FUNCTION(Runtime_CreateApiFunction) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(FunctionTemplateInfo, data, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, prototype, 1);
+  return *isolate->factory()->CreateApiFunction(data, prototype);
+}
+
+
+RUNTIME_FUNCTION(Runtime_IsTemplate) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, arg, 0);
+  bool result = arg->IsObjectTemplateInfo() || arg->IsFunctionTemplateInfo();
+  return isolate->heap()->ToBoolean(result);
+}
+
+
+RUNTIME_FUNCTION(Runtime_GetTemplateField) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_CHECKED(HeapObject, templ, 0);
+  CONVERT_SMI_ARG_CHECKED(index, 1);
+  int offset = index * kPointerSize + HeapObject::kHeaderSize;
+  InstanceType type = templ->map()->instance_type();
+  RUNTIME_ASSERT(type == FUNCTION_TEMPLATE_INFO_TYPE ||
+                 type == OBJECT_TEMPLATE_INFO_TYPE);
+  RUNTIME_ASSERT(offset > 0);
+  if (type == FUNCTION_TEMPLATE_INFO_TYPE) {
+    RUNTIME_ASSERT(offset < FunctionTemplateInfo::kSize);
+  } else {
+    RUNTIME_ASSERT(offset < ObjectTemplateInfo::kSize);
+  }
+  return *HeapObject::RawField(templ, offset);
+}
+
+
+// Transform getter or setter into something DefineAccessor can handle.
+static Handle<Object> InstantiateAccessorComponent(Isolate* isolate,
+                                                   Handle<Object> component) {
+  if (component->IsUndefined()) return isolate->factory()->undefined_value();
+  Handle<FunctionTemplateInfo> info =
+      Handle<FunctionTemplateInfo>::cast(component);
+  return Utils::OpenHandle(*Utils::ToLocal(info)->GetFunction());
+}
+
+
+RUNTIME_FUNCTION(Runtime_DefineApiAccessorProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 5);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, getter, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, setter, 3);
+  CONVERT_SMI_ARG_CHECKED(attribute, 4);
+  RUNTIME_ASSERT(getter->IsUndefined() || getter->IsFunctionTemplateInfo());
+  RUNTIME_ASSERT(setter->IsUndefined() || setter->IsFunctionTemplateInfo());
+  RUNTIME_ASSERT(PropertyDetails::AttributesField::is_valid(
+      static_cast<PropertyAttributes>(attribute)));
+  RETURN_FAILURE_ON_EXCEPTION(
+      isolate, JSObject::DefineAccessor(
+                   object, name, InstantiateAccessorComponent(isolate, getter),
+                   InstantiateAccessorComponent(isolate, setter),
+                   static_cast<PropertyAttributes>(attribute)));
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_AddPropertyForTemplate) {
+  HandleScope scope(isolate);
+  RUNTIME_ASSERT(args.length() == 4);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
+  CONVERT_SMI_ARG_CHECKED(unchecked_attributes, 3);
+  RUNTIME_ASSERT(
+      (unchecked_attributes & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
+  // Compute attributes.
+  PropertyAttributes attributes =
+      static_cast<PropertyAttributes>(unchecked_attributes);
+
+#ifdef DEBUG
+  bool duplicate;
+  if (key->IsName()) {
+    LookupIterator it(object, Handle<Name>::cast(key),
+                      LookupIterator::OWN_SKIP_INTERCEPTOR);
+    Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
+    DCHECK(maybe.has_value);
+    duplicate = it.IsFound();
+  } else {
+    uint32_t index = 0;
+    RUNTIME_ASSERT(key->ToArrayIndex(&index));
+    Maybe<bool> maybe = JSReceiver::HasOwnElement(object, index);
+    if (!maybe.has_value) return isolate->heap()->exception();
+    duplicate = maybe.value;
+  }
+  if (duplicate) {
+    Handle<Object> args[1] = {key};
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate,
+        NewTypeError("duplicate_template_property", HandleVector(args, 1)));
+  }
+#endif
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      Runtime::DefineObjectProperty(object, key, value, attributes));
+  return *result;
+}
+}
+}  // namespace v8::internal

src/runtime/runtime-array.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/v8.h"
+
+#include "src/arguments.h"
+#include "src/runtime/runtime.h"
+#include "src/runtime/runtime-utils.h"
+
+namespace v8 {
+namespace internal {
+
+RUNTIME_FUNCTION(Runtime_FinishArrayPrototypeSetup) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSArray, prototype, 0);
+  Object* length = prototype->length();
+  RUNTIME_ASSERT(length->IsSmi() && Smi::cast(length)->value() == 0);
+  RUNTIME_ASSERT(prototype->HasFastSmiOrObjectElements());
+  // This is necessary to enable fast checks for absence of elements
+  // on Array.prototype and below.
+  prototype->set_elements(isolate->heap()->empty_fixed_array());
+  return Smi::FromInt(0);
+}
+
+
+static void InstallBuiltin(Isolate* isolate, Handle<JSObject> holder,
+                           const char* name, Builtins::Name builtin_name) {
+  Handle<String> key = isolate->factory()->InternalizeUtf8String(name);
+  Handle<Code> code(isolate->builtins()->builtin(builtin_name));
+  Handle<JSFunction> optimized =
+      isolate->factory()->NewFunctionWithoutPrototype(key, code);
+  optimized->shared()->DontAdaptArguments();
+  JSObject::AddProperty(holder, key, optimized, NONE);
+}
+
+
+RUNTIME_FUNCTION(Runtime_SpecialArrayFunctions) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 0);
+  Handle<JSObject> holder =
+      isolate->factory()->NewJSObject(isolate->object_function());
+
+  InstallBuiltin(isolate, holder, "pop", Builtins::kArrayPop);
+  InstallBuiltin(isolate, holder, "push", Builtins::kArrayPush);
+  InstallBuiltin(isolate, holder, "shift", Builtins::kArrayShift);
+  InstallBuiltin(isolate, holder, "unshift", Builtins::kArrayUnshift);
+  InstallBuiltin(isolate, holder, "slice", Builtins::kArraySlice);
+  InstallBuiltin(isolate, holder, "splice", Builtins::kArraySplice);
+  InstallBuiltin(isolate, holder, "concat", Builtins::kArrayConcat);
+
+  return *holder;
+}
+
+
+RUNTIME_FUNCTION(Runtime_TransitionElementsKind) {
+  HandleScope scope(isolate);
+  RUNTIME_ASSERT(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Map, map, 1);
+  JSObject::TransitionElementsKind(array, map->elements_kind());
+  return *array;
+}
+
+
+// Push an object unto an array of objects if it is not already in the
+// array.  Returns true if the element was pushed on the stack and
+// false otherwise.
+RUNTIME_FUNCTION(Runtime_PushIfAbsent) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, element, 1);
+  RUNTIME_ASSERT(array->HasFastSmiOrObjectElements());
+  int length = Smi::cast(array->length())->value();
+  FixedArray* elements = FixedArray::cast(array->elements());
+  for (int i = 0; i < length; i++) {
+    if (elements->get(i) == *element) return isolate->heap()->false_value();
+  }
+
+  // Strict not needed. Used for cycle detection in Array join implementation.
+  RETURN_FAILURE_ON_EXCEPTION(
+      isolate, JSObject::SetFastElement(array, length, element, SLOPPY, true));
+  return isolate->heap()->true_value();
+}
+
+
+/**
+ * A simple visitor visits every element of Array's.
+ * The backend storage can be a fixed array for fast elements case,
+ * or a dictionary for sparse array. Since Dictionary is a subtype
+ * of FixedArray, the class can be used by both fast and slow cases.
+ * The second parameter of the constructor, fast_elements, specifies
+ * whether the storage is a FixedArray or Dictionary.
+ *
+ * An index limit is used to deal with the situation that a result array
+ * length overflows 32-bit non-negative integer.
+ */
+class ArrayConcatVisitor {
+ public:
+  ArrayConcatVisitor(Isolate* isolate, Handle<FixedArray> storage,
+                     bool fast_elements)
+      : isolate_(isolate),
+        storage_(Handle<FixedArray>::cast(
+            isolate->global_handles()->Create(*storage))),
+        index_offset_(0u),
+        fast_elements_(fast_elements),
+        exceeds_array_limit_(false) {}
+
+  ~ArrayConcatVisitor() { clear_storage(); }
+
+  void visit(uint32_t i, Handle<Object> elm) {
+    if (i > JSObject::kMaxElementCount - index_offset_) {
+      exceeds_array_limit_ = true;
+      return;
+    }
+    uint32_t index = index_offset_ + i;
+
+    if (fast_elements_) {
+      if (index < static_cast<uint32_t>(storage_->length())) {
+        storage_->set(index, *elm);
+        return;
+      }
+      // Our initial estimate of length was foiled, possibly by
+      // getters on the arrays increasing the length of later arrays
+      // during iteration.
+      // This shouldn't happen in anything but pathological cases.
+      SetDictionaryMode();
+      // Fall-through to dictionary mode.
+    }
+    DCHECK(!fast_elements_);
+    Handle<SeededNumberDictionary> dict(
+        SeededNumberDictionary::cast(*storage_));
+    Handle<SeededNumberDictionary> result =
+        SeededNumberDictionary::AtNumberPut(dict, index, elm);
+    if (!result.is_identical_to(dict)) {
+      // Dictionary needed to grow.
+      clear_storage();
+      set_storage(*result);
+    }
+  }
+
+  void increase_index_offset(uint32_t delta) {
+    if (JSObject::kMaxElementCount - index_offset_ < delta) {
+      index_offset_ = JSObject::kMaxElementCount;
+    } else {
+      index_offset_ += delta;
+    }
+    // If the initial length estimate was off (see special case in visit()),
+    // but the array blowing the limit didn't contain elements beyond the
+    // provided-for index range, go to dictionary mode now.
+    if (fast_elements_ &&
+        index_offset_ >
+            static_cast<uint32_t>(FixedArrayBase::cast(*storage_)->length())) {
+      SetDictionaryMode();
+    }
+  }
+
+  bool exceeds_array_limit() { return exceeds_array_limit_; }
+
+  Handle<JSArray> ToArray() {
+    Handle<JSArray> array = isolate_->factory()->NewJSArray(0);
+    Handle<Object> length =
+        isolate_->factory()->NewNumber(static_cast<double>(index_offset_));
+    Handle<Map> map = JSObject::GetElementsTransitionMap(
+        array, fast_elements_ ? FAST_HOLEY_ELEMENTS : DICTIONARY_ELEMENTS);
+    array->set_map(*map);
+    array->set_length(*length);
+    array->set_elements(*storage_);
+    return array;
+  }
+
+ private:
+  // Convert storage to dictionary mode.
+  void SetDictionaryMode() {
+    DCHECK(fast_elements_);
+    Handle<FixedArray> current_storage(*storage_);
+    Handle<SeededNumberDictionary> slow_storage(
+        SeededNumberDictionary::New(isolate_, current_storage->length()));
+    uint32_t current_length = static_cast<uint32_t>(current_storage->length());
+    for (uint32_t i = 0; i < current_length; i++) {
+      HandleScope loop_scope(isolate_);
+      Handle<Object> element(current_storage->get(i), isolate_);
+      if (!element->IsTheHole()) {
+        Handle<SeededNumberDictionary> new_storage =
+            SeededNumberDictionary::AtNumberPut(slow_storage, i, element);
+        if (!new_storage.is_identical_to(slow_storage)) {
+          slow_storage = loop_scope.CloseAndEscape(new_storage);
+        }
+      }
+    }
+    clear_storage();
+    set_storage(*slow_storage);
+    fast_elements_ = false;
+  }
+
+  inline void clear_storage() {
+    GlobalHandles::Destroy(Handle<Object>::cast(storage_).location());
+  }
+
+  inline void set_storage(FixedArray* storage) {
+    storage_ =
+        Handle<FixedArray>::cast(isolate_->global_handles()->Create(storage));
+  }
+
+  Isolate* isolate_;
+  Handle<FixedArray> storage_;  // Always a global handle.
+  // Index after last seen index. Always less than or equal to
+  // JSObject::kMaxElementCount.
+  uint32_t index_offset_;
+  bool fast_elements_ : 1;
+  bool exceeds_array_limit_ : 1;
+};
+
+
+static uint32_t EstimateElementCount(Handle<JSArray> array) {
+  uint32_t length = static_cast<uint32_t>(array->length()->Number());
+  int element_count = 0;
+  switch (array->GetElementsKind()) {
+    case FAST_SMI_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
+    case FAST_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS: {
+      // Fast elements can't have lengths that are not representable by
+      // a 32-bit signed integer.
+      DCHECK(static_cast<int32_t>(FixedArray::kMaxLength) >= 0);
+      int fast_length = static_cast<int>(length);
+      Handle<FixedArray> elements(FixedArray::cast(array->elements()));
+      for (int i = 0; i < fast_length; i++) {
+        if (!elements->get(i)->IsTheHole()) element_count++;
+      }
+      break;
+    }
+    case FAST_DOUBLE_ELEMENTS:
+    case FAST_HOLEY_DOUBLE_ELEMENTS: {
+      // Fast elements can't have lengths that are not representable by
+      // a 32-bit signed integer.
+      DCHECK(static_cast<int32_t>(FixedDoubleArray::kMaxLength) >= 0);
+      int fast_length = static_cast<int>(length);
+      if (array->elements()->IsFixedArray()) {
+        DCHECK(FixedArray::cast(array->elements())->length() == 0);
+        break;
+      }
+      Handle<FixedDoubleArray> elements(
+          FixedDoubleArray::cast(array->elements()));
+      for (int i = 0; i < fast_length; i++) {
+        if (!elements->is_the_hole(i)) element_count++;
+      }
+      break;
+    }
+    case DICTIONARY_ELEMENTS: {
+      Handle<SeededNumberDictionary> dictionary(
+          SeededNumberDictionary::cast(array->elements()));
+      int capacity = dictionary->Capacity();
+      for (int i = 0; i < capacity; i++) {
+        Handle<Object> key(dictionary->KeyAt(i), array->GetIsolate());
+        if (dictionary->IsKey(*key)) {
+          element_count++;
+        }
+      }
+      break;
+    }
+    case SLOPPY_ARGUMENTS_ELEMENTS:
+#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
+  case EXTERNAL_##TYPE##_ELEMENTS:                      \
+  case TYPE##_ELEMENTS:
+
+      TYPED_ARRAYS(TYPED_ARRAY_CASE)
+#undef TYPED_ARRAY_CASE
+      // External arrays are always dense.
+      return length;
+  }
+  // As an estimate, we assume that the prototype doesn't contain any
+  // inherited elements.
+  return element_count;
+}
+
+
+template <class ExternalArrayClass, class ElementType>
+static void IterateExternalArrayElements(Isolate* isolate,
+                                         Handle<JSObject> receiver,
+                                         bool elements_are_ints,
+                                         bool elements_are_guaranteed_smis,
+                                         ArrayConcatVisitor* visitor) {
+  Handle<ExternalArrayClass> array(
+      ExternalArrayClass::cast(receiver->elements()));
+  uint32_t len = static_cast<uint32_t>(array->length());
+
+  DCHECK(visitor != NULL);
+  if (elements_are_ints) {
+    if (elements_are_guaranteed_smis) {
+      for (uint32_t j = 0; j < len; j++) {
+        HandleScope loop_scope(isolate);
+        Handle<Smi> e(Smi::FromInt(static_cast<int>(array->get_scalar(j))),
+                      isolate);
+        visitor->visit(j, e);
+      }
+    } else {
+      for (uint32_t j = 0; j < len; j++) {
+        HandleScope loop_scope(isolate);
+        int64_t val = static_cast<int64_t>(array->get_scalar(j));
+        if (Smi::IsValid(static_cast<intptr_t>(val))) {
+          Handle<Smi> e(Smi::FromInt(static_cast<int>(val)), isolate);
+          visitor->visit(j, e);
+        } else {
+          Handle<Object> e =
+              isolate->factory()->NewNumber(static_cast<ElementType>(val));
+          visitor->visit(j, e);
+        }
+      }
+    }
+  } else {
+    for (uint32_t j = 0; j < len; j++) {
+      HandleScope loop_scope(isolate);
+      Handle<Object> e = isolate->factory()->NewNumber(array->get_scalar(j));
+      visitor->visit(j, e);
+    }
+  }
+}
+
+
+// Used for sorting indices in a List<uint32_t>.
+static int compareUInt32(const uint32_t* ap, const uint32_t* bp) {
+  uint32_t a = *ap;
+  uint32_t b = *bp;
+  return (a == b) ? 0 : (a < b) ? -1 : 1;
+}
+
+
+static void CollectElementIndices(Handle<JSObject> object, uint32_t range,
+                                  List<uint32_t>* indices) {
+  Isolate* isolate = object->GetIsolate();
+  ElementsKind kind = object->GetElementsKind();
+  switch (kind) {
+    case FAST_SMI_ELEMENTS:
+    case FAST_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS: {
+      Handle<FixedArray> elements(FixedArray::cast(object->elements()));
+      uint32_t length = static_cast<uint32_t>(elements->length());
+      if (range < length) length = range;
+      for (uint32_t i = 0; i < length; i++) {
+        if (!elements->get(i)->IsTheHole()) {
+          indices->Add(i);
+        }
+      }
+      break;
+    }
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
+    case FAST_DOUBLE_ELEMENTS: {
+      if (object->elements()->IsFixedArray()) {
+        DCHECK(object->elements()->length() == 0);
+        break;
+      }
+      Handle<FixedDoubleArray> elements(
+          FixedDoubleArray::cast(object->elements()));
+      uint32_t length = static_cast<uint32_t>(elements->length());
+      if (range < length) length = range;
+      for (uint32_t i = 0; i < length; i++) {
+        if (!elements->is_the_hole(i)) {
+          indices->Add(i);
+        }
+      }
+      break;
+    }
+    case DICTIONARY_ELEMENTS: {
+      Handle<SeededNumberDictionary> dict(
+          SeededNumberDictionary::cast(object->elements()));
+      uint32_t capacity = dict->Capacity();
+      for (uint32_t j = 0; j < capacity; j++) {
+        HandleScope loop_scope(isolate);
+        Handle<Object> k(dict->KeyAt(j), isolate);
+        if (dict->IsKey(*k)) {
+          DCHECK(k->IsNumber());
+          uint32_t index = static_cast<uint32_t>(k->Number());
+          if (index < range) {
+            indices->Add(index);
+          }
+        }
+      }
+      break;
+    }
+#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
+  case TYPE##_ELEMENTS:                                 \
+  case EXTERNAL_##TYPE##_ELEMENTS:
+
+      TYPED_ARRAYS(TYPED_ARRAY_CASE)
+#undef TYPED_ARRAY_CASE
+      {
+        uint32_t length = static_cast<uint32_t>(
+            FixedArrayBase::cast(object->elements())->length());
+        if (range <= length) {
+          length = range;
+          // We will add all indices, so we might as well clear it first
+          // and avoid duplicates.
+          indices->Clear();
+        }
+        for (uint32_t i = 0; i < length; i++) {
+          indices->Add(i);
+        }
+        if (length == range) return;  // All indices accounted for already.
+        break;
+      }
+    case SLOPPY_ARGUMENTS_ELEMENTS: {
+      MaybeHandle<Object> length_obj =
+          Object::GetProperty(object, isolate->factory()->length_string());
+      double length_num = length_obj.ToHandleChecked()->Number();
+      uint32_t length = static_cast<uint32_t>(DoubleToInt32(length_num));
+      ElementsAccessor* accessor = object->GetElementsAccessor();
+      for (uint32_t i = 0; i < length; i++) {
+        if (accessor->HasElement(object, object, i)) {
+          indices->Add(i);
+        }
+      }
+      break;
+    }
+  }
+
+  PrototypeIterator iter(isolate, object);
+  if (!iter.IsAtEnd()) {
+    // The prototype will usually have no inherited element indices,
+    // but we have to check.
+    CollectElementIndices(
+        Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter)), range,
+        indices);
+  }
+}
+
+
+/**
+ * A helper function that visits elements of a JSArray in numerical
+ * order.
+ *
+ * The visitor argument called for each existing element in the array
+ * with the element index and the element's value.
+ * Afterwards it increments the base-index of the visitor by the array
+ * length.
+ * Returns false if any access threw an exception, otherwise true.
+ */
+static bool IterateElements(Isolate* isolate, Handle<JSArray> receiver,
+                            ArrayConcatVisitor* visitor) {
+  uint32_t length = static_cast<uint32_t>(receiver->length()->Number());
+  switch (receiver->GetElementsKind()) {
+    case FAST_SMI_ELEMENTS:
+    case FAST_ELEMENTS:
+    case FAST_HOLEY_SMI_ELEMENTS:
+    case FAST_HOLEY_ELEMENTS: {
+      // Run through the elements FixedArray and use HasElement and GetElement
+      // to check the prototype for missing elements.
+      Handle<FixedArray> elements(FixedArray::cast(receiver->elements()));
+      int fast_length = static_cast<int>(length);
+      DCHECK(fast_length <= elements->length());
+      for (int j = 0; j < fast_length; j++) {
+        HandleScope loop_scope(isolate);
+        Handle<Object> element_value(elements->get(j), isolate);
+        if (!element_value->IsTheHole()) {
+          visitor->visit(j, element_value);
+        } else {
+          Maybe<bool> maybe = JSReceiver::HasElement(receiver, j);
+          if (!maybe.has_value) return false;
+          if (maybe.value) {
+            // Call GetElement on receiver, not its prototype, or getters won't
+            // have the correct receiver.
+            ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+                isolate, element_value,
+                Object::GetElement(isolate, receiver, j), false);
+            visitor->visit(j, element_value);
+          }
+        }
+      }
+      break;
+    }
+    case FAST_HOLEY_DOUBLE_ELEMENTS:
+    case FAST_DOUBLE_ELEMENTS: {
+      // Empty array is FixedArray but not FixedDoubleArray.
+      if (length == 0) break;
+      // Run through the elements FixedArray and use HasElement and GetElement
+      // to check the prototype for missing elements.
+      if (receiver->elements()->IsFixedArray()) {
+        DCHECK(receiver->elements()->length() == 0);
+        break;
+      }
+      Handle<FixedDoubleArray> elements(
+          FixedDoubleArray::cast(receiver->elements()));
+      int fast_length = static_cast<int>(length);
+      DCHECK(fast_length <= elements->length());
+      for (int j = 0; j < fast_length; j++) {
+        HandleScope loop_scope(isolate);
+        if (!elements->is_the_hole(j)) {
+          double double_value = elements->get_scalar(j);
+          Handle<Object> element_value =
+              isolate->factory()->NewNumber(double_value);
+          visitor->visit(j, element_value);
+        } else {
+          Maybe<bool> maybe = JSReceiver::HasElement(receiver, j);
+          if (!maybe.has_value) return false;
+          if (maybe.value) {
+            // Call GetElement on receiver, not its prototype, or getters won't
+            // have the correct receiver.
+            Handle<Object> element_value;
+            ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+                isolate, element_value,
+                Object::GetElement(isolate, receiver, j), false);
+            visitor->visit(j, element_value);
+          }
+        }
+      }
+      break;
+    }
+    case DICTIONARY_ELEMENTS: {
+      Handle<SeededNumberDictionary> dict(receiver->element_dictionary());
+      List<uint32_t> indices(dict->Capacity() / 2);
+      // Collect all indices in the object and the prototypes less
+      // than length. This might introduce duplicates in the indices list.
+      CollectElementIndices(receiver, length, &indices);
+      indices.Sort(&compareUInt32);
+      int j = 0;
+      int n = indices.length();
+      while (j < n) {
+        HandleScope loop_scope(isolate);
+        uint32_t index = indices[j];
+        Handle<Object> element;
+        ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+            isolate, element, Object::GetElement(isolate, receiver, index),
+            false);
+        visitor->visit(index, element);
+        // Skip to next different index (i.e., omit duplicates).
+        do {
+          j++;
+        } while (j < n && indices[j] == index);
+      }
+      break;
+    }
+    case EXTERNAL_UINT8_CLAMPED_ELEMENTS: {
+      Handle<ExternalUint8ClampedArray> pixels(
+          ExternalUint8ClampedArray::cast(receiver->elements()));
+      for (uint32_t j = 0; j < length; j++) {
+        Handle<Smi> e(Smi::FromInt(pixels->get_scalar(j)), isolate);
+        visitor->visit(j, e);
+      }
+      break;
+    }
+    case EXTERNAL_INT8_ELEMENTS: {
+      IterateExternalArrayElements<ExternalInt8Array, int8_t>(
+          isolate, receiver, true, true, visitor);
+      break;
+    }
+    case EXTERNAL_UINT8_ELEMENTS: {
+      IterateExternalArrayElements<ExternalUint8Array, uint8_t>(
+          isolate, receiver, true, true, visitor);
+      break;
+    }
+    case EXTERNAL_INT16_ELEMENTS: {
+      IterateExternalArrayElements<ExternalInt16Array, int16_t>(
+          isolate, receiver, true, true, visitor);
+      break;
+    }
+    case EXTERNAL_UINT16_ELEMENTS: {
+      IterateExternalArrayElements<ExternalUint16Array, uint16_t>(
+          isolate, receiver, true, true, visitor);
+      break;
+    }
+    case EXTERNAL_INT32_ELEMENTS: {
+      IterateExternalArrayElements<ExternalInt32Array, int32_t>(
+          isolate, receiver, true, false, visitor);
+      break;
+    }
+    case EXTERNAL_UINT32_ELEMENTS: {
+      IterateExternalArrayElements<ExternalUint32Array, uint32_t>(
+          isolate, receiver, true, false, visitor);
+      break;
+    }
+    case EXTERNAL_FLOAT32_ELEMENTS: {
+      IterateExternalArrayElements<ExternalFloat32Array, float>(
+          isolate, receiver, false, false, visitor);
+      break;
+    }
+    case EXTERNAL_FLOAT64_ELEMENTS: {
+      IterateExternalArrayElements<ExternalFloat64Array, double>(
+          isolate, receiver, false, false, visitor);
+      break;
+    }
+    default:
+      UNREACHABLE();
+      break;
+  }
+  visitor->increase_index_offset(length);
+  return true;
+}
+
+
+/**
+ * Array::concat implementation.
+ * See ECMAScript 262, 15.4.4.4.
+ * TODO(581): Fix non-compliance for very large concatenations and update to
+ * following the ECMAScript 5 specification.
+ */
+RUNTIME_FUNCTION(Runtime_ArrayConcat) {
+  HandleScope handle_scope(isolate);
+  DCHECK(args.length() == 1);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSArray, arguments, 0);
+  int argument_count = static_cast<int>(arguments->length()->Number());
+  RUNTIME_ASSERT(arguments->HasFastObjectElements());
+  Handle<FixedArray> elements(FixedArray::cast(arguments->elements()));
+
+  // Pass 1: estimate the length and number of elements of the result.
+  // The actual length can be larger if any of the arguments have getters
+  // that mutate other arguments (but will otherwise be precise).
+  // The number of elements is precise if there are no inherited elements.
+
+  ElementsKind kind = FAST_SMI_ELEMENTS;
+
+  uint32_t estimate_result_length = 0;
+  uint32_t estimate_nof_elements = 0;
+  for (int i = 0; i < argument_count; i++) {
+    HandleScope loop_scope(isolate);
+    Handle<Object> obj(elements->get(i), isolate);
+    uint32_t length_estimate;
+    uint32_t element_estimate;
+    if (obj->IsJSArray()) {
+      Handle<JSArray> array(Handle<JSArray>::cast(obj));
+      length_estimate = static_cast<uint32_t>(array->length()->Number());
+      if (length_estimate != 0) {
+        ElementsKind array_kind =
+            GetPackedElementsKind(array->map()->elements_kind());
+        if (IsMoreGeneralElementsKindTransition(kind, array_kind)) {
+          kind = array_kind;
+        }
+      }
+      element_estimate = EstimateElementCount(array);
+    } else {
+      if (obj->IsHeapObject()) {
+        if (obj->IsNumber()) {
+          if (IsMoreGeneralElementsKindTransition(kind, FAST_DOUBLE_ELEMENTS)) {
+            kind = FAST_DOUBLE_ELEMENTS;
+          }
+        } else if (IsMoreGeneralElementsKindTransition(kind, FAST_ELEMENTS)) {
+          kind = FAST_ELEMENTS;
+        }
+      }
+      length_estimate = 1;
+      element_estimate = 1;
+    }
+    // Avoid overflows by capping at kMaxElementCount.
+    if (JSObject::kMaxElementCount - estimate_result_length < length_estimate) {
+      estimate_result_length = JSObject::kMaxElementCount;
+    } else {
+      estimate_result_length += length_estimate;
+    }
+    if (JSObject::kMaxElementCount - estimate_nof_elements < element_estimate) {
+      estimate_nof_elements = JSObject::kMaxElementCount;
+    } else {
+      estimate_nof_elements += element_estimate;
+    }
+  }
+
+  // If estimated number of elements is more than half of length, a
+  // fixed array (fast case) is more time and space-efficient than a
+  // dictionary.
+  bool fast_case = (estimate_nof_elements * 2) >= estimate_result_length;
+
+  if (fast_case && kind == FAST_DOUBLE_ELEMENTS) {
+    Handle<FixedArrayBase> storage =
+        isolate->factory()->NewFixedDoubleArray(estimate_result_length);
+    int j = 0;
+    bool failure = false;
+    if (estimate_result_length > 0) {
+      Handle<FixedDoubleArray> double_storage =
+          Handle<FixedDoubleArray>::cast(storage);
+      for (int i = 0; i < argument_count; i++) {
+        Handle<Object> obj(elements->get(i), isolate);
+        if (obj->IsSmi()) {
+          double_storage->set(j, Smi::cast(*obj)->value());
+          j++;
+        } else if (obj->IsNumber()) {
+          double_storage->set(j, obj->Number());
+          j++;
+        } else {
+          JSArray* array = JSArray::cast(*obj);
+          uint32_t length = static_cast<uint32_t>(array->length()->Number());
+          switch (array->map()->elements_kind()) {
+            case FAST_HOLEY_DOUBLE_ELEMENTS:
+            case FAST_DOUBLE_ELEMENTS: {
+              // Empty array is FixedArray but not FixedDoubleArray.
+              if (length == 0) break;
+              FixedDoubleArray* elements =
+                  FixedDoubleArray::cast(array->elements());
+              for (uint32_t i = 0; i < length; i++) {
+                if (elements->is_the_hole(i)) {
+                  // TODO(jkummerow/verwaest): We could be a bit more clever
+                  // here: Check if there are no elements/getters on the
+                  // prototype chain, and if so, allow creation of a holey
+                  // result array.
+                  // Same thing below (holey smi case).
+                  failure = true;
+                  break;
+                }
+                double double_value = elements->get_scalar(i);
+                double_storage->set(j, double_value);
+                j++;
+              }
+              break;
+            }
+            case FAST_HOLEY_SMI_ELEMENTS:
+            case FAST_SMI_ELEMENTS: {
+              FixedArray* elements(FixedArray::cast(array->elements()));
+              for (uint32_t i = 0; i < length; i++) {
+                Object* element = elements->get(i);
+                if (element->IsTheHole()) {
+                  failure = true;
+                  break;
+                }
+                int32_t int_value = Smi::cast(element)->value();
+                double_storage->set(j, int_value);
+                j++;
+              }
+              break;
+            }
+            case FAST_HOLEY_ELEMENTS:
+            case FAST_ELEMENTS:
+              DCHECK_EQ(0, length);
+              break;
+            default:
+              UNREACHABLE();
+          }
+        }
+        if (failure) break;
+      }
+    }
+    if (!failure) {
+      Handle<JSArray> array = isolate->factory()->NewJSArray(0);
+      Smi* length = Smi::FromInt(j);
+      Handle<Map> map;
+      map = JSObject::GetElementsTransitionMap(array, kind);
+      array->set_map(*map);
+      array->set_length(length);
+      array->set_elements(*storage);
+      return *array;
+    }
+    // In case of failure, fall through.
+  }
+
+  Handle<FixedArray> storage;
+  if (fast_case) {
+    // The backing storage array must have non-existing elements to preserve
+    // holes across concat operations.
+    storage =
+        isolate->factory()->NewFixedArrayWithHoles(estimate_result_length);
+  } else {
+    // TODO(126): move 25% pre-allocation logic into Dictionary::Allocate
+    uint32_t at_least_space_for =
+        estimate_nof_elements + (estimate_nof_elements >> 2);
+    storage = Handle<FixedArray>::cast(
+        SeededNumberDictionary::New(isolate, at_least_space_for));
+  }
+
+  ArrayConcatVisitor visitor(isolate, storage, fast_case);
+
+  for (int i = 0; i < argument_count; i++) {
+    Handle<Object> obj(elements->get(i), isolate);
+    if (obj->IsJSArray()) {
+      Handle<JSArray> array = Handle<JSArray>::cast(obj);
+      if (!IterateElements(isolate, array, &visitor)) {
+        return isolate->heap()->exception();
+      }
+    } else {
+      visitor.visit(0, obj);
+      visitor.increase_index_offset(1);
+    }
+  }
+
+  if (visitor.exceeds_array_limit()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate,
+        NewRangeError("invalid_array_length", HandleVector<Object>(NULL, 0)));
+  }
+  return *visitor.ToArray();
+}
+
+
+// Moves all own elements of an object, that are below a limit, to positions
+// starting at zero. All undefined values are placed after non-undefined values,
+// and are followed by non-existing element. Does not change the length
+// property.
+// Returns the number of non-undefined elements collected.
+// Returns -1 if hole removal is not supported by this method.
+RUNTIME_FUNCTION(Runtime_RemoveArrayHoles) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]);
+  return *JSObject::PrepareElementsForSort(object, limit);
+}
+
+
+// Move contents of argument 0 (an array) to argument 1 (an array)
+RUNTIME_FUNCTION(Runtime_MoveArrayContents) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSArray, from, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSArray, to, 1);
+  JSObject::ValidateElements(from);
+  JSObject::ValidateElements(to);
+
+  Handle<FixedArrayBase> new_elements(from->elements());
+  ElementsKind from_kind = from->GetElementsKind();
+  Handle<Map> new_map = JSObject::GetElementsTransitionMap(to, from_kind);
+  JSObject::SetMapAndElements(to, new_map, new_elements);
+  to->set_length(from->length());
+
+  JSObject::ResetElements(from);
+  from->set_length(Smi::FromInt(0));
+
+  JSObject::ValidateElements(to);
+  return *to;
+}
+
+
+// How many elements does this object/array have?
+RUNTIME_FUNCTION(Runtime_EstimateNumberOfElements) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
+  Handle<FixedArrayBase> elements(array->elements(), isolate);
+  SealHandleScope shs(isolate);
+  if (elements->IsDictionary()) {
+    int result =
+        Handle<SeededNumberDictionary>::cast(elements)->NumberOfElements();
+    return Smi::FromInt(result);
+  } else {
+    DCHECK(array->length()->IsSmi());
+    // For packed elements, we know the exact number of elements
+    int length = elements->length();
+    ElementsKind kind = array->GetElementsKind();
+    if (IsFastPackedElementsKind(kind)) {
+      return Smi::FromInt(length);
+    }
+    // For holey elements, take samples from the buffer checking for holes
+    // to generate the estimate.
+    const int kNumberOfHoleCheckSamples = 97;
+    int increment = (length < kNumberOfHoleCheckSamples)
+                        ? 1
+                        : static_cast<int>(length / kNumberOfHoleCheckSamples);
+    ElementsAccessor* accessor = array->GetElementsAccessor();
+    int holes = 0;
+    for (int i = 0; i < length; i += increment) {
+      if (!accessor->HasElement(array, array, i, elements)) {
+        ++holes;
+      }
+    }
+    int estimate = static_cast<int>((kNumberOfHoleCheckSamples - holes) /
+                                    kNumberOfHoleCheckSamples * length);
+    return Smi::FromInt(estimate);
+  }
+}
+
+
+// Returns an array that tells you where in the [0, length) interval an array
+// might have elements.  Can either return an array of keys (positive integers
+// or undefined) or a number representing the positive length of an interval
+// starting at index 0.
+// Intervals can span over some keys that are not in the object.
+RUNTIME_FUNCTION(Runtime_GetArrayKeys) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
+  CONVERT_NUMBER_CHECKED(uint32_t, length, Uint32, args[1]);
+  if (array->elements()->IsDictionary()) {
+    Handle<FixedArray> keys = isolate->factory()->empty_fixed_array();
+    for (PrototypeIterator iter(isolate, array,
+                                PrototypeIterator::START_AT_RECEIVER);
+         !iter.IsAtEnd(); iter.Advance()) {
+      if (PrototypeIterator::GetCurrent(iter)->IsJSProxy() ||
+          JSObject::cast(*PrototypeIterator::GetCurrent(iter))
+              ->HasIndexedInterceptor()) {
+        // Bail out if we find a proxy or interceptor, likely not worth
+        // collecting keys in that case.
+        return *isolate->factory()->NewNumberFromUint(length);
+      }
+      Handle<JSObject> current =
+          Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter));
+      Handle<FixedArray> current_keys =
+          isolate->factory()->NewFixedArray(current->NumberOfOwnElements(NONE));
+      current->GetOwnElementKeys(*current_keys, NONE);
+      ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+          isolate, keys, FixedArray::UnionOfKeys(keys, current_keys));
+    }
+    // Erase any keys >= length.
+    // TODO(adamk): Remove this step when the contract of %GetArrayKeys
+    // is changed to let this happen on the JS side.
+    for (int i = 0; i < keys->length(); i++) {
+      if (NumberToUint32(keys->get(i)) >= length) keys->set_undefined(i);
+    }
+    return *isolate->factory()->NewJSArrayWithElements(keys);
+  } else {
+    RUNTIME_ASSERT(array->HasFastSmiOrObjectElements() ||
+                   array->HasFastDoubleElements());
+    uint32_t actual_length = static_cast<uint32_t>(array->elements()->length());
+    return *isolate->factory()->NewNumberFromUint(Min(actual_length, length));
+  }
+}
+
+
+static Object* ArrayConstructorCommon(Isolate* isolate,
+                                      Handle<JSFunction> constructor,
+                                      Handle<AllocationSite> site,
+                                      Arguments* caller_args) {
+  Factory* factory = isolate->factory();
+
+  bool holey = false;
+  bool can_use_type_feedback = true;
+  if (caller_args->length() == 1) {
+    Handle<Object> argument_one = caller_args->at<Object>(0);
+    if (argument_one->IsSmi()) {
+      int value = Handle<Smi>::cast(argument_one)->value();
+      if (value < 0 || value >= JSObject::kInitialMaxFastElementArray) {
+        // the array is a dictionary in this case.
+        can_use_type_feedback = false;
+      } else if (value != 0) {
+        holey = true;
+      }
+    } else {
+      // Non-smi length argument produces a dictionary
+      can_use_type_feedback = false;
+    }
+  }
+
+  Handle<JSArray> array;
+  if (!site.is_null() && can_use_type_feedback) {
+    ElementsKind to_kind = site->GetElementsKind();
+    if (holey && !IsFastHoleyElementsKind(to_kind)) {
+      to_kind = GetHoleyElementsKind(to_kind);
+      // Update the allocation site info to reflect the advice alteration.
+      site->SetElementsKind(to_kind);
+    }
+
+    // We should allocate with an initial map that reflects the allocation site
+    // advice. Therefore we use AllocateJSObjectFromMap instead of passing
+    // the constructor.
+    Handle<Map> initial_map(constructor->initial_map(), isolate);
+    if (to_kind != initial_map->elements_kind()) {
+      initial_map = Map::AsElementsKind(initial_map, to_kind);
+    }
+
+    // If we don't care to track arrays of to_kind ElementsKind, then
+    // don't emit a memento for them.
+    Handle<AllocationSite> allocation_site;
+    if (AllocationSite::GetMode(to_kind) == TRACK_ALLOCATION_SITE) {
+      allocation_site = site;
+    }
+
+    array = Handle<JSArray>::cast(factory->NewJSObjectFromMap(
+        initial_map, NOT_TENURED, true, allocation_site));
+  } else {
+    array = Handle<JSArray>::cast(factory->NewJSObject(constructor));
+
+    // We might need to transition to holey
+    ElementsKind kind = constructor->initial_map()->elements_kind();
+    if (holey && !IsFastHoleyElementsKind(kind)) {
+      kind = GetHoleyElementsKind(kind);
+      JSObject::TransitionElementsKind(array, kind);
+    }
+  }
+
+  factory->NewJSArrayStorage(array, 0, 0, DONT_INITIALIZE_ARRAY_ELEMENTS);
+
+  ElementsKind old_kind = array->GetElementsKind();
+  RETURN_FAILURE_ON_EXCEPTION(
+      isolate, ArrayConstructInitializeElements(array, caller_args));
+  if (!site.is_null() &&
+      (old_kind != array->GetElementsKind() || !can_use_type_feedback)) {
+    // The arguments passed in caused a transition. This kind of complexity
+    // can't be dealt with in the inlined hydrogen array constructor case.
+    // We must mark the allocationsite as un-inlinable.
+    site->SetDoNotInlineCall();
+  }
+  return *array;
+}
+
+
+RUNTIME_FUNCTION(Runtime_ArrayConstructor) {
+  HandleScope scope(isolate);
+  // If we get 2 arguments then they are the stub parameters (constructor, type
+  // info).  If we get 4, then the first one is a pointer to the arguments
+  // passed by the caller, and the last one is the length of the arguments
+  // passed to the caller (redundant, but useful to check on the deoptimizer
+  // with an assert).
+  Arguments empty_args(0, NULL);
+  bool no_caller_args = args.length() == 2;
+  DCHECK(no_caller_args || args.length() == 4);
+  int parameters_start = no_caller_args ? 0 : 1;
+  Arguments* caller_args =
+      no_caller_args ? &empty_args : reinterpret_cast<Arguments*>(args[0]);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, parameters_start);
+  CONVERT_ARG_HANDLE_CHECKED(Object, type_info, parameters_start + 1);
+#ifdef DEBUG
+  if (!no_caller_args) {
+    CONVERT_SMI_ARG_CHECKED(arg_count, parameters_start + 2);
+    DCHECK(arg_count == caller_args->length());
+  }
+#endif
+
+  Handle<AllocationSite> site;
+  if (!type_info.is_null() &&
+      *type_info != isolate->heap()->undefined_value()) {
+    site = Handle<AllocationSite>::cast(type_info);
+    DCHECK(!site->SitePointsToLiteral());
+  }
+
+  return ArrayConstructorCommon(isolate, constructor, site, caller_args);
+}
+
+
+RUNTIME_FUNCTION(Runtime_InternalArrayConstructor) {
+  HandleScope scope(isolate);
+  Arguments empty_args(0, NULL);
+  bool no_caller_args = args.length() == 1;
+  DCHECK(no_caller_args || args.length() == 3);
+  int parameters_start = no_caller_args ? 0 : 1;
+  Arguments* caller_args =
+      no_caller_args ? &empty_args : reinterpret_cast<Arguments*>(args[0]);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, parameters_start);
+#ifdef DEBUG
+  if (!no_caller_args) {
+    CONVERT_SMI_ARG_CHECKED(arg_count, parameters_start + 1);
+    DCHECK(arg_count == caller_args->length());
+  }
+#endif
+  return ArrayConstructorCommon(isolate, constructor,
+                                Handle<AllocationSite>::null(), caller_args);
+}
+
+
+RUNTIME_FUNCTION(Runtime_NormalizeElements) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
+  RUNTIME_ASSERT(!array->HasExternalArrayElements() &&
+                 !array->HasFixedTypedArrayElements());
+  JSObject::NormalizeElements(array);
+  return *array;
+}
+
+
+// TODO(dcarney): remove this function when TurboFan supports it.
+// Takes the object to be iterated over and the result of GetPropertyNamesFast
+// Returns pair (cache_array, cache_type).
+RUNTIME_FUNCTION_RETURN_PAIR(Runtime_ForInInit) {
+  SealHandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  // This simulates CONVERT_ARG_HANDLE_CHECKED for calls returning pairs.
+  // Not worth creating a macro atm as this function should be removed.
+  if (!args[0]->IsJSReceiver() || !args[1]->IsObject()) {
+    Object* error = isolate->ThrowIllegalOperation();
+    return MakePair(error, isolate->heap()->undefined_value());
+  }
+  Handle<JSReceiver> object = args.at<JSReceiver>(0);
+  Handle<Object> cache_type = args.at<Object>(1);
+  if (cache_type->IsMap()) {
+    // Enum cache case.
+    if (Map::EnumLengthBits::decode(Map::cast(*cache_type)->bit_field3()) ==
+        0) {
+      // 0 length enum.
+      // Can't handle this case in the graph builder,
+      // so transform it into the empty fixed array case.
+      return MakePair(isolate->heap()->empty_fixed_array(), Smi::FromInt(1));
+    }
+    return MakePair(object->map()->instance_descriptors()->GetEnumCache(),
+                    *cache_type);
+  } else {
+    // FixedArray case.
+    Smi* new_cache_type = Smi::FromInt(object->IsJSProxy() ? 0 : 1);
+    return MakePair(*Handle<FixedArray>::cast(cache_type), new_cache_type);
+  }
+}
+
+
+// TODO(dcarney): remove this function when TurboFan supports it.
+RUNTIME_FUNCTION(Runtime_ForInCacheArrayLength) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, cache_type, 0);
+  CONVERT_ARG_HANDLE_CHECKED(FixedArray, array, 1);
+  int length = 0;
+  if (cache_type->IsMap()) {
+    length = Map::cast(*cache_type)->EnumLength();
+  } else {
+    DCHECK(cache_type->IsSmi());
+    length = array->length();
+  }
+  return Smi::FromInt(length);
+}
+
+
+// TODO(dcarney): remove this function when TurboFan supports it.
+// Takes (the object to be iterated over,
+//        cache_array from ForInInit,
+//        cache_type from ForInInit,
+//        the current index)
+// Returns pair (array[index], needs_filtering).
+RUNTIME_FUNCTION_RETURN_PAIR(Runtime_ForInNext) {
+  SealHandleScope scope(isolate);
+  DCHECK(args.length() == 4);
+  int32_t index;
+  // This simulates CONVERT_ARG_HANDLE_CHECKED for calls returning pairs.
+  // Not worth creating a macro atm as this function should be removed.
+  if (!args[0]->IsJSReceiver() || !args[1]->IsFixedArray() ||
+      !args[2]->IsObject() || !args[3]->ToInt32(&index)) {
+    Object* error = isolate->ThrowIllegalOperation();
+    return MakePair(error, isolate->heap()->undefined_value());
+  }
+  Handle<JSReceiver> object = args.at<JSReceiver>(0);
+  Handle<FixedArray> array = args.at<FixedArray>(1);
+  Handle<Object> cache_type = args.at<Object>(2);
+  // Figure out first if a slow check is needed for this object.
+  bool slow_check_needed = false;
+  if (cache_type->IsMap()) {
+    if (object->map() != Map::cast(*cache_type)) {
+      // Object transitioned.  Need slow check.
+      slow_check_needed = true;
+    }
+  } else {
+    // No slow check needed for proxies.
+    slow_check_needed = Smi::cast(*cache_type)->value() == 1;
+  }
+  return MakePair(array->get(index),
+                  isolate->heap()->ToBoolean(slow_check_needed));
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_IsArray) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  return isolate->heap()->ToBoolean(obj->IsJSArray());
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_HasCachedArrayIndex) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  return isolate->heap()->false_value();
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_GetCachedArrayIndex) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_FastOneByteArrayJoin) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 2);
+  return isolate->heap()->undefined_value();
+}
+}
+}  // namespace v8::internal

src/runtime/runtime-debug.cc

@@ -2732,5 +2732,11 @@ RUNTIME_FUNCTION(RuntimeReference_DebugIsActive) {
   SealHandleScope shs(isolate);
   return Smi::FromInt(isolate->debug()->is_active());
 }
+
+
+RUNTIME_FUNCTION(RuntimeReference_DebugBreakInOptimizedCode) {
+  UNIMPLEMENTED();
+  return NULL;
+}
 }
 }  // namespace v8::internal

src/runtime/runtime-internal.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/v8.h"
+
+#include "src/arguments.h"
+#include "src/bootstrapper.h"
+#include "src/debug.h"
+#include "src/runtime/runtime.h"
+#include "src/runtime/runtime-utils.h"
+
+namespace v8 {
+namespace internal {
+
+RUNTIME_FUNCTION(Runtime_CheckIsBootstrapping) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 0);
+  RUNTIME_ASSERT(isolate->bootstrapper()->IsActive());
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_Throw) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+
+  return isolate->Throw(args[0]);
+}
+
+
+RUNTIME_FUNCTION(Runtime_ReThrow) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+
+  return isolate->ReThrow(args[0]);
+}
+
+
+RUNTIME_FUNCTION(Runtime_PromoteScheduledException) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 0);
+  return isolate->PromoteScheduledException();
+}
+
+
+RUNTIME_FUNCTION(Runtime_ThrowReferenceError) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, name, 0);
+  THROW_NEW_ERROR_RETURN_FAILURE(
+      isolate, NewReferenceError("not_defined", HandleVector(&name, 1)));
+}
+
+
+RUNTIME_FUNCTION(Runtime_PromiseRejectEvent) {
+  DCHECK(args.length() == 3);
+  HandleScope scope(isolate);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 1);
+  CONVERT_BOOLEAN_ARG_CHECKED(debug_event, 2);
+  if (debug_event) isolate->debug()->OnPromiseReject(promise, value);
+  Handle<Symbol> key = isolate->factory()->promise_has_handler_symbol();
+  // Do not report if we actually have a handler.
+  if (JSObject::GetDataProperty(promise, key)->IsUndefined()) {
+    isolate->ReportPromiseReject(promise, value,
+                                 v8::kPromiseRejectWithNoHandler);
+  }
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_PromiseRevokeReject) {
+  DCHECK(args.length() == 1);
+  HandleScope scope(isolate);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
+  Handle<Symbol> key = isolate->factory()->promise_has_handler_symbol();
+  // At this point, no revocation has been issued before
+  RUNTIME_ASSERT(JSObject::GetDataProperty(promise, key)->IsUndefined());
+  isolate->ReportPromiseReject(promise, Handle<Object>(),
+                               v8::kPromiseHandlerAddedAfterReject);
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_PromiseHasHandlerSymbol) {
+  DCHECK(args.length() == 0);
+  return isolate->heap()->promise_has_handler_symbol();
+}
+
+
+RUNTIME_FUNCTION(Runtime_StackGuard) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 0);
+
+  // First check if this is a real stack overflow.
+  StackLimitCheck check(isolate);
+  if (check.JsHasOverflowed()) {
+    return isolate->StackOverflow();
+  }
+
+  return isolate->stack_guard()->HandleInterrupts();
+}
+
+
+RUNTIME_FUNCTION(Runtime_Interrupt) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 0);
+  return isolate->stack_guard()->HandleInterrupts();
+}
+
+
+RUNTIME_FUNCTION(Runtime_AllocateInNewSpace) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_SMI_ARG_CHECKED(size, 0);
+  RUNTIME_ASSERT(IsAligned(size, kPointerSize));
+  RUNTIME_ASSERT(size > 0);
+  RUNTIME_ASSERT(size <= Page::kMaxRegularHeapObjectSize);
+  return *isolate->factory()->NewFillerObject(size, false, NEW_SPACE);
+}
+
+
+RUNTIME_FUNCTION(Runtime_AllocateInTargetSpace) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_SMI_ARG_CHECKED(size, 0);
+  CONVERT_SMI_ARG_CHECKED(flags, 1);
+  RUNTIME_ASSERT(IsAligned(size, kPointerSize));
+  RUNTIME_ASSERT(size > 0);
+  RUNTIME_ASSERT(size <= Page::kMaxRegularHeapObjectSize);
+  bool double_align = AllocateDoubleAlignFlag::decode(flags);
+  AllocationSpace space = AllocateTargetSpace::decode(flags);
+  return *isolate->factory()->NewFillerObject(size, double_align, space);
+}
+
+
+// Collect the raw data for a stack trace.  Returns an array of 4
+// element segments each containing a receiver, function, code and
+// native code offset.
+RUNTIME_FUNCTION(Runtime_CollectStackTrace) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, error_object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, caller, 1);
+
+  if (!isolate->bootstrapper()->IsActive()) {
+    // Optionally capture a more detailed stack trace for the message.
+    isolate->CaptureAndSetDetailedStackTrace(error_object);
+    // Capture a simple stack trace for the stack property.
+    isolate->CaptureAndSetSimpleStackTrace(error_object, caller);
+  }
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_GetFromCache) {
+  SealHandleScope shs(isolate);
+  // This is only called from codegen, so checks might be more lax.
+  CONVERT_ARG_CHECKED(JSFunctionResultCache, cache, 0);
+  CONVERT_ARG_CHECKED(Object, key, 1);
+
+  {
+    DisallowHeapAllocation no_alloc;
+
+    int finger_index = cache->finger_index();
+    Object* o = cache->get(finger_index);
+    if (o == key) {
+      // The fastest case: hit the same place again.
+      return cache->get(finger_index + 1);
+    }
+
+    for (int i = finger_index - 2; i >= JSFunctionResultCache::kEntriesIndex;
+         i -= 2) {
+      o = cache->get(i);
+      if (o == key) {
+        cache->set_finger_index(i);
+        return cache->get(i + 1);
+      }
+    }
+
+    int size = cache->size();
+    DCHECK(size <= cache->length());
+
+    for (int i = size - 2; i > finger_index; i -= 2) {
+      o = cache->get(i);
+      if (o == key) {
+        cache->set_finger_index(i);
+        return cache->get(i + 1);
+      }
+    }
+  }
+
+  // There is no value in the cache.  Invoke the function and cache result.
+  HandleScope scope(isolate);
+
+  Handle<JSFunctionResultCache> cache_handle(cache);
+  Handle<Object> key_handle(key, isolate);
+  Handle<Object> value;
+  {
+    Handle<JSFunction> factory(JSFunction::cast(
+        cache_handle->get(JSFunctionResultCache::kFactoryIndex)));
+    // TODO(antonm): consider passing a receiver when constructing a cache.
+    Handle<JSObject> receiver(isolate->global_proxy());
+    // This handle is nor shared, nor used later, so it's safe.
+    Handle<Object> argv[] = {key_handle};
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, value,
+        Execution::Call(isolate, factory, receiver, arraysize(argv), argv));
+  }
+
+#ifdef VERIFY_HEAP
+  if (FLAG_verify_heap) {
+    cache_handle->JSFunctionResultCacheVerify();
+  }
+#endif
+
+  // Function invocation may have cleared the cache.  Reread all the data.
+  int finger_index = cache_handle->finger_index();
+  int size = cache_handle->size();
+
+  // If we have spare room, put new data into it, otherwise evict post finger
+  // entry which is likely to be the least recently used.
+  int index = -1;
+  if (size < cache_handle->length()) {
+    cache_handle->set_size(size + JSFunctionResultCache::kEntrySize);
+    index = size;
+  } else {
+    index = finger_index + JSFunctionResultCache::kEntrySize;
+    if (index == cache_handle->length()) {
+      index = JSFunctionResultCache::kEntriesIndex;
+    }
+  }
+
+  DCHECK(index % 2 == 0);
+  DCHECK(index >= JSFunctionResultCache::kEntriesIndex);
+  DCHECK(index < cache_handle->length());
+
+  cache_handle->set(index, *key_handle);
+  cache_handle->set(index + 1, *value);
+  cache_handle->set_finger_index(index);
+
+#ifdef VERIFY_HEAP
+  if (FLAG_verify_heap) {
+    cache_handle->JSFunctionResultCacheVerify();
+  }
+#endif
+
+  return *value;
+}
+
+
+RUNTIME_FUNCTION(Runtime_MessageGetStartPosition) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSMessageObject, message, 0);
+  return Smi::FromInt(message->start_position());
+}
+
+
+RUNTIME_FUNCTION(Runtime_MessageGetScript) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSMessageObject, message, 0);
+  return message->script();
+}
+
+
+RUNTIME_FUNCTION(Runtime_IS_VAR) {
+  UNREACHABLE();  // implemented as macro in the parser
+  return NULL;
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_GetFromCache) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_SMI_ARG_CHECKED(id, 0);
+  args[0] = isolate->native_context()->jsfunction_result_caches()->get(id);
+  return __RT_impl_Runtime_GetFromCache(args, isolate);
+}
+}
+}  // namespace v8::internal

src/runtime/runtime-numbers.cc

@@ -5,6 +5,7 @@
 #include "src/v8.h"
 
 #include "src/arguments.h"
+#include "src/bootstrapper.h"
 #include "src/codegen.h"
 #include "src/misc-intrinsics.h"
 #include "src/runtime/runtime.h"
@@ -557,6 +558,21 @@ RUNTIME_FUNCTION(Runtime_SmiLexicographicCompare) {
 }
 
 
+RUNTIME_FUNCTION(Runtime_GetRootNaN) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 0);
+  RUNTIME_ASSERT(isolate->bootstrapper()->IsActive());
+  return isolate->heap()->nan_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_MaxSmi) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 0);
+  return Smi::FromInt(Smi::kMaxValue);
+}
+
+
 RUNTIME_FUNCTION(RuntimeReference_NumberToString) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_NumberToStringRT(args, isolate);

src/runtime/runtime-object.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/v8.h"
+
+#include "src/arguments.h"
+#include "src/bootstrapper.h"
+#include "src/debug.h"
+#include "src/runtime/runtime.h"
+#include "src/runtime/runtime-utils.h"
+
+namespace v8 {
+namespace internal {
+
+// Returns a single character string where first character equals
+// string->Get(index).
+static Handle<Object> GetCharAt(Handle<String> string, uint32_t index) {
+  if (index < static_cast<uint32_t>(string->length())) {
+    Factory* factory = string->GetIsolate()->factory();
+    return factory->LookupSingleCharacterStringFromCode(
+        String::Flatten(string)->Get(index));
+  }
+  return Execution::CharAt(string, index);
+}
+
+
+MaybeHandle<Object> Runtime::GetElementOrCharAt(Isolate* isolate,
+                                                Handle<Object> object,
+                                                uint32_t index) {
+  // Handle [] indexing on Strings
+  if (object->IsString()) {
+    Handle<Object> result = GetCharAt(Handle<String>::cast(object), index);
+    if (!result->IsUndefined()) return result;
+  }
+
+  // Handle [] indexing on String objects
+  if (object->IsStringObjectWithCharacterAt(index)) {
+    Handle<JSValue> js_value = Handle<JSValue>::cast(object);
+    Handle<Object> result =
+        GetCharAt(Handle<String>(String::cast(js_value->value())), index);
+    if (!result->IsUndefined()) return result;
+  }
+
+  Handle<Object> result;
+  if (object->IsString() || object->IsNumber() || object->IsBoolean()) {
+    PrototypeIterator iter(isolate, object);
+    return Object::GetElement(isolate, PrototypeIterator::GetCurrent(iter),
+                              index);
+  } else {
+    return Object::GetElement(isolate, object, index);
+  }
+}
+
+
+MaybeHandle<Name> Runtime::ToName(Isolate* isolate, Handle<Object> key) {
+  if (key->IsName()) {
+    return Handle<Name>::cast(key);
+  } else {
+    Handle<Object> converted;
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, converted,
+                               Execution::ToString(isolate, key), Name);
+    return Handle<Name>::cast(converted);
+  }
+}
+
+
+MaybeHandle<Object> Runtime::HasObjectProperty(Isolate* isolate,
+                                               Handle<JSReceiver> object,
+                                               Handle<Object> key) {
+  Maybe<bool> maybe;
+  // Check if the given key is an array index.
+  uint32_t index;
+  if (key->ToArrayIndex(&index)) {
+    maybe = JSReceiver::HasElement(object, index);
+  } else {
+    // Convert the key to a name - possibly by calling back into JavaScript.
+    Handle<Name> name;
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, name, ToName(isolate, key), Object);
+
+    maybe = JSReceiver::HasProperty(object, name);
+  }
+
+  if (!maybe.has_value) return MaybeHandle<Object>();
+  return isolate->factory()->ToBoolean(maybe.value);
+}
+
+
+MaybeHandle<Object> Runtime::GetObjectProperty(Isolate* isolate,
+                                               Handle<Object> object,
+                                               Handle<Object> key) {
+  if (object->IsUndefined() || object->IsNull()) {
+    Handle<Object> args[2] = {key, object};
+    THROW_NEW_ERROR(isolate, NewTypeError("non_object_property_load",
+                                          HandleVector(args, 2)),
+                    Object);
+  }
+
+  // Check if the given key is an array index.
+  uint32_t index;
+  if (key->ToArrayIndex(&index)) {
+    return GetElementOrCharAt(isolate, object, index);
+  }
+
+  // Convert the key to a name - possibly by calling back into JavaScript.
+  Handle<Name> name;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, name, ToName(isolate, key), Object);
+
+  // Check if the name is trivially convertible to an index and get
+  // the element if so.
+  if (name->AsArrayIndex(&index)) {
+    return GetElementOrCharAt(isolate, object, index);
+  } else {
+    return Object::GetProperty(object, name);
+  }
+}
+
+
+MaybeHandle<Object> Runtime::SetObjectProperty(Isolate* isolate,
+                                               Handle<Object> object,
+                                               Handle<Object> key,
+                                               Handle<Object> value,
+                                               StrictMode strict_mode) {
+  if (object->IsUndefined() || object->IsNull()) {
+    Handle<Object> args[2] = {key, object};
+    THROW_NEW_ERROR(isolate, NewTypeError("non_object_property_store",
+                                          HandleVector(args, 2)),
+                    Object);
+  }
+
+  if (object->IsJSProxy()) {
+    Handle<Object> name_object;
+    if (key->IsSymbol()) {
+      name_object = key;
+    } else {
+      ASSIGN_RETURN_ON_EXCEPTION(isolate, name_object,
+                                 Execution::ToString(isolate, key), Object);
+    }
+    Handle<Name> name = Handle<Name>::cast(name_object);
+    return Object::SetProperty(Handle<JSProxy>::cast(object), name, value,
+                               strict_mode);
+  }
+
+  // Check if the given key is an array index.
+  uint32_t index;
+  if (key->ToArrayIndex(&index)) {
+    // TODO(verwaest): Support non-JSObject receivers.
+    if (!object->IsJSObject()) return value;
+    Handle<JSObject> js_object = Handle<JSObject>::cast(object);
+
+    // In Firefox/SpiderMonkey, Safari and Opera you can access the characters
+    // of a string using [] notation.  We need to support this too in
+    // JavaScript.
+    // In the case of a String object we just need to redirect the assignment to
+    // the underlying string if the index is in range.  Since the underlying
+    // string does nothing with the assignment then we can ignore such
+    // assignments.
+    if (js_object->IsStringObjectWithCharacterAt(index)) {
+      return value;
+    }
+
+    JSObject::ValidateElements(js_object);
+    if (js_object->HasExternalArrayElements() ||
+        js_object->HasFixedTypedArrayElements()) {
+      if (!value->IsNumber() && !value->IsUndefined()) {
+        ASSIGN_RETURN_ON_EXCEPTION(isolate, value,
+                                   Execution::ToNumber(isolate, value), Object);
+      }
+    }
+
+    MaybeHandle<Object> result = JSObject::SetElement(
+        js_object, index, value, NONE, strict_mode, true, SET_PROPERTY);
+    JSObject::ValidateElements(js_object);
+
+    return result.is_null() ? result : value;
+  }
+
+  if (key->IsName()) {
+    Handle<Name> name = Handle<Name>::cast(key);
+    if (name->AsArrayIndex(&index)) {
+      // TODO(verwaest): Support non-JSObject receivers.
+      if (!object->IsJSObject()) return value;
+      Handle<JSObject> js_object = Handle<JSObject>::cast(object);
+      if (js_object->HasExternalArrayElements()) {
+        if (!value->IsNumber() && !value->IsUndefined()) {
+          ASSIGN_RETURN_ON_EXCEPTION(
+              isolate, value, Execution::ToNumber(isolate, value), Object);
+        }
+      }
+      return JSObject::SetElement(js_object, index, value, NONE, strict_mode,
+                                  true, SET_PROPERTY);
+    } else {
+      if (name->IsString()) name = String::Flatten(Handle<String>::cast(name));
+      return Object::SetProperty(object, name, value, strict_mode);
+    }
+  }
+
+  // Call-back into JavaScript to convert the key to a string.
+  Handle<Object> converted;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, converted,
+                             Execution::ToString(isolate, key), Object);
+  Handle<String> name = Handle<String>::cast(converted);
+
+  if (name->AsArrayIndex(&index)) {
+    // TODO(verwaest): Support non-JSObject receivers.
+    if (!object->IsJSObject()) return value;
+    Handle<JSObject> js_object = Handle<JSObject>::cast(object);
+    return JSObject::SetElement(js_object, index, value, NONE, strict_mode,
+                                true, SET_PROPERTY);
+  }
+  return Object::SetProperty(object, name, value, strict_mode);
+}
+
+
+MaybeHandle<Object> Runtime::DefineObjectProperty(Handle<JSObject> js_object,
+                                                  Handle<Object> key,
+                                                  Handle<Object> value,
+                                                  PropertyAttributes attr) {
+  Isolate* isolate = js_object->GetIsolate();
+  // Check if the given key is an array index.
+  uint32_t index;
+  if (key->ToArrayIndex(&index)) {
+    // In Firefox/SpiderMonkey, Safari and Opera you can access the characters
+    // of a string using [] notation.  We need to support this too in
+    // JavaScript.
+    // In the case of a String object we just need to redirect the assignment to
+    // the underlying string if the index is in range.  Since the underlying
+    // string does nothing with the assignment then we can ignore such
+    // assignments.
+    if (js_object->IsStringObjectWithCharacterAt(index)) {
+      return value;
+    }
+
+    return JSObject::SetElement(js_object, index, value, attr, SLOPPY, false,
+                                DEFINE_PROPERTY);
+  }
+
+  if (key->IsName()) {
+    Handle<Name> name = Handle<Name>::cast(key);
+    if (name->AsArrayIndex(&index)) {
+      return JSObject::SetElement(js_object, index, value, attr, SLOPPY, false,
+                                  DEFINE_PROPERTY);
+    } else {
+      if (name->IsString()) name = String::Flatten(Handle<String>::cast(name));
+      return JSObject::SetOwnPropertyIgnoreAttributes(js_object, name, value,
+                                                      attr);
+    }
+  }
+
+  // Call-back into JavaScript to convert the key to a string.
+  Handle<Object> converted;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, converted,
+                             Execution::ToString(isolate, key), Object);
+  Handle<String> name = Handle<String>::cast(converted);
+
+  if (name->AsArrayIndex(&index)) {
+    return JSObject::SetElement(js_object, index, value, attr, SLOPPY, false,
+                                DEFINE_PROPERTY);
+  } else {
+    return JSObject::SetOwnPropertyIgnoreAttributes(js_object, name, value,
+                                                    attr);
+  }
+}
+
+
+MaybeHandle<Object> Runtime::DeleteObjectProperty(Isolate* isolate,
+                                                  Handle<JSReceiver> receiver,
+                                                  Handle<Object> key,
+                                                  JSReceiver::DeleteMode mode) {
+  // Check if the given key is an array index.
+  uint32_t index;
+  if (key->ToArrayIndex(&index)) {
+    // In Firefox/SpiderMonkey, Safari and Opera you can access the
+    // characters of a string using [] notation.  In the case of a
+    // String object we just need to redirect the deletion to the
+    // underlying string if the index is in range.  Since the
+    // underlying string does nothing with the deletion, we can ignore
+    // such deletions.
+    if (receiver->IsStringObjectWithCharacterAt(index)) {
+      return isolate->factory()->true_value();
+    }
+
+    return JSReceiver::DeleteElement(receiver, index, mode);
+  }
+
+  Handle<Name> name;
+  if (key->IsName()) {
+    name = Handle<Name>::cast(key);
+  } else {
+    // Call-back into JavaScript to convert the key to a string.
+    Handle<Object> converted;
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, converted,
+                               Execution::ToString(isolate, key), Object);
+    name = Handle<String>::cast(converted);
+  }
+
+  if (name->IsString()) name = String::Flatten(Handle<String>::cast(name));
+  return JSReceiver::DeleteProperty(receiver, name, mode);
+}
+
+
+RUNTIME_FUNCTION(Runtime_GetPrototype) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, obj, 0);
+  // We don't expect access checks to be needed on JSProxy objects.
+  DCHECK(!obj->IsAccessCheckNeeded() || obj->IsJSObject());
+  PrototypeIterator iter(isolate, obj, PrototypeIterator::START_AT_RECEIVER);
+  do {
+    if (PrototypeIterator::GetCurrent(iter)->IsAccessCheckNeeded() &&
+        !isolate->MayNamedAccess(
+            Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter)),
+            isolate->factory()->proto_string(), v8::ACCESS_GET)) {
+      isolate->ReportFailedAccessCheck(
+          Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter)),
+          v8::ACCESS_GET);
+      RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+      return isolate->heap()->undefined_value();
+    }
+    iter.AdvanceIgnoringProxies();
+    if (PrototypeIterator::GetCurrent(iter)->IsJSProxy()) {
+      return *PrototypeIterator::GetCurrent(iter);
+    }
+  } while (!iter.IsAtEnd(PrototypeIterator::END_AT_NON_HIDDEN));
+  return *PrototypeIterator::GetCurrent(iter);
+}
+
+
+RUNTIME_FUNCTION(Runtime_InternalSetPrototype) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, prototype, 1);
+  DCHECK(!obj->IsAccessCheckNeeded());
+  DCHECK(!obj->map()->is_observed());
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, JSObject::SetPrototype(obj, prototype, false));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_SetPrototype) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, prototype, 1);
+  if (obj->IsAccessCheckNeeded() &&
+      !isolate->MayNamedAccess(obj, isolate->factory()->proto_string(),
+                               v8::ACCESS_SET)) {
+    isolate->ReportFailedAccessCheck(obj, v8::ACCESS_SET);
+    RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+    return isolate->heap()->undefined_value();
+  }
+  if (obj->map()->is_observed()) {
+    Handle<Object> old_value =
+        Object::GetPrototypeSkipHiddenPrototypes(isolate, obj);
+    Handle<Object> result;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, result, JSObject::SetPrototype(obj, prototype, true));
+
+    Handle<Object> new_value =
+        Object::GetPrototypeSkipHiddenPrototypes(isolate, obj);
+    if (!new_value->SameValue(*old_value)) {
+      JSObject::EnqueueChangeRecord(
+          obj, "setPrototype", isolate->factory()->proto_string(), old_value);
+    }
+    return *result;
+  }
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, JSObject::SetPrototype(obj, prototype, true));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_IsInPrototypeChain) {
+  HandleScope shs(isolate);
+  DCHECK(args.length() == 2);
+  // See ECMA-262, section 15.3.5.3, page 88 (steps 5 - 8).
+  CONVERT_ARG_HANDLE_CHECKED(Object, O, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, V, 1);
+  PrototypeIterator iter(isolate, V, PrototypeIterator::START_AT_RECEIVER);
+  while (true) {
+    iter.AdvanceIgnoringProxies();
+    if (iter.IsAtEnd()) return isolate->heap()->false_value();
+    if (iter.IsAtEnd(O)) return isolate->heap()->true_value();
+  }
+}
+
+
+// Enumerator used as indices into the array returned from GetOwnProperty
+enum PropertyDescriptorIndices {
+  IS_ACCESSOR_INDEX,
+  VALUE_INDEX,
+  GETTER_INDEX,
+  SETTER_INDEX,
+  WRITABLE_INDEX,
+  ENUMERABLE_INDEX,
+  CONFIGURABLE_INDEX,
+  DESCRIPTOR_SIZE
+};
+
+
+MUST_USE_RESULT static MaybeHandle<Object> GetOwnProperty(Isolate* isolate,
+                                                          Handle<JSObject> obj,
+                                                          Handle<Name> name) {
+  Heap* heap = isolate->heap();
+  Factory* factory = isolate->factory();
+
+  PropertyAttributes attrs;
+  uint32_t index = 0;
+  Handle<Object> value;
+  MaybeHandle<AccessorPair> maybe_accessors;
+  // TODO(verwaest): Unify once indexed properties can be handled by the
+  // LookupIterator.
+  if (name->AsArrayIndex(&index)) {
+    // Get attributes.
+    Maybe<PropertyAttributes> maybe =
+        JSReceiver::GetOwnElementAttribute(obj, index);
+    if (!maybe.has_value) return MaybeHandle<Object>();
+    attrs = maybe.value;
+    if (attrs == ABSENT) return factory->undefined_value();
+
+    // Get AccessorPair if present.
+    maybe_accessors = JSObject::GetOwnElementAccessorPair(obj, index);
+
+    // Get value if not an AccessorPair.
+    if (maybe_accessors.is_null()) {
+      ASSIGN_RETURN_ON_EXCEPTION(
+          isolate, value, Runtime::GetElementOrCharAt(isolate, obj, index),
+          Object);
+    }
+  } else {
+    // Get attributes.
+    LookupIterator it(obj, name, LookupIterator::HIDDEN);
+    Maybe<PropertyAttributes> maybe = JSObject::GetPropertyAttributes(&it);
+    if (!maybe.has_value) return MaybeHandle<Object>();
+    attrs = maybe.value;
+    if (attrs == ABSENT) return factory->undefined_value();
+
+    // Get AccessorPair if present.
+    if (it.state() == LookupIterator::ACCESSOR &&
+        it.GetAccessors()->IsAccessorPair()) {
+      maybe_accessors = Handle<AccessorPair>::cast(it.GetAccessors());
+    }
+
+    // Get value if not an AccessorPair.
+    if (maybe_accessors.is_null()) {
+      ASSIGN_RETURN_ON_EXCEPTION(isolate, value, Object::GetProperty(&it),
+                                 Object);
+    }
+  }
+  DCHECK(!isolate->has_pending_exception());
+  Handle<FixedArray> elms = factory->NewFixedArray(DESCRIPTOR_SIZE);
+  elms->set(ENUMERABLE_INDEX, heap->ToBoolean((attrs & DONT_ENUM) == 0));
+  elms->set(CONFIGURABLE_INDEX, heap->ToBoolean((attrs & DONT_DELETE) == 0));
+  elms->set(IS_ACCESSOR_INDEX, heap->ToBoolean(!maybe_accessors.is_null()));
+
+  Handle<AccessorPair> accessors;
+  if (maybe_accessors.ToHandle(&accessors)) {
+    Handle<Object> getter(accessors->GetComponent(ACCESSOR_GETTER), isolate);
+    Handle<Object> setter(accessors->GetComponent(ACCESSOR_SETTER), isolate);
+    elms->set(GETTER_INDEX, *getter);
+    elms->set(SETTER_INDEX, *setter);
+  } else {
+    elms->set(WRITABLE_INDEX, heap->ToBoolean((attrs & READ_ONLY) == 0));
+    elms->set(VALUE_INDEX, *value);
+  }
+
+  return factory->NewJSArrayWithElements(elms);
+}
+
+
+// Returns an array with the property description:
+//  if args[1] is not a property on args[0]
+//          returns undefined
+//  if args[1] is a data property on args[0]
+//         [false, value, Writeable, Enumerable, Configurable]
+//  if args[1] is an accessor on args[0]
+//         [true, GetFunction, SetFunction, Enumerable, Configurable]
+RUNTIME_FUNCTION(Runtime_GetOwnProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
+                                     GetOwnProperty(isolate, obj, name));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_PreventExtensions) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
+                                     JSObject::PreventExtensions(obj));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_IsExtensible) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSObject, obj, 0);
+  if (obj->IsJSGlobalProxy()) {
+    PrototypeIterator iter(isolate, obj);
+    if (iter.IsAtEnd()) return isolate->heap()->false_value();
+    DCHECK(iter.GetCurrent()->IsJSGlobalObject());
+    obj = JSObject::cast(iter.GetCurrent());
+  }
+  return isolate->heap()->ToBoolean(obj->map()->is_extensible());
+}
+
+
+RUNTIME_FUNCTION(Runtime_DisableAccessChecks) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(HeapObject, object, 0);
+  Handle<Map> old_map(object->map());
+  bool needs_access_checks = old_map->is_access_check_needed();
+  if (needs_access_checks) {
+    // Copy map so it won't interfere constructor's initial map.
+    Handle<Map> new_map = Map::Copy(old_map);
+    new_map->set_is_access_check_needed(false);
+    JSObject::MigrateToMap(Handle<JSObject>::cast(object), new_map);
+  }
+  return isolate->heap()->ToBoolean(needs_access_checks);
+}
+
+
+RUNTIME_FUNCTION(Runtime_EnableAccessChecks) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  Handle<Map> old_map(object->map());
+  RUNTIME_ASSERT(!old_map->is_access_check_needed());
+  // Copy map so it won't interfere constructor's initial map.
+  Handle<Map> new_map = Map::Copy(old_map);
+  new_map->set_is_access_check_needed(true);
+  JSObject::MigrateToMap(object, new_map);
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_OptimizeObjectForAddingMultipleProperties) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_SMI_ARG_CHECKED(properties, 1);
+  // Conservative upper limit to prevent fuzz tests from going OOM.
+  RUNTIME_ASSERT(properties <= 100000);
+  if (object->HasFastProperties() && !object->IsJSGlobalProxy()) {
+    JSObject::NormalizeProperties(object, KEEP_INOBJECT_PROPERTIES, properties);
+  }
+  return *object;
+}
+
+
+RUNTIME_FUNCTION(Runtime_ObjectFreeze) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+
+  // %ObjectFreeze is a fast path and these cases are handled elsewhere.
+  RUNTIME_ASSERT(!object->HasSloppyArgumentsElements() &&
+                 !object->map()->is_observed() && !object->IsJSProxy());
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, JSObject::Freeze(object));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_GetProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, Runtime::GetObjectProperty(isolate, object, key));
+  return *result;
+}
+
+
+MUST_USE_RESULT static MaybeHandle<Object> TransitionElements(
+    Handle<Object> object, ElementsKind to_kind, Isolate* isolate) {
+  HandleScope scope(isolate);
+  if (!object->IsJSObject()) {
+    isolate->ThrowIllegalOperation();
+    return MaybeHandle<Object>();
+  }
+  ElementsKind from_kind =
+      Handle<JSObject>::cast(object)->map()->elements_kind();
+  if (Map::IsValidElementsTransition(from_kind, to_kind)) {
+    JSObject::TransitionElementsKind(Handle<JSObject>::cast(object), to_kind);
+    return object;
+  }
+  isolate->ThrowIllegalOperation();
+  return MaybeHandle<Object>();
+}
+
+
+// KeyedGetProperty is called from KeyedLoadIC::GenerateGeneric.
+RUNTIME_FUNCTION(Runtime_KeyedGetProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+
+  CONVERT_ARG_HANDLE_CHECKED(Object, receiver_obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key_obj, 1);
+
+  // Fast cases for getting named properties of the receiver JSObject
+  // itself.
+  //
+  // The global proxy objects has to be excluded since LookupOwn on
+  // the global proxy object can return a valid result even though the
+  // global proxy object never has properties.  This is the case
+  // because the global proxy object forwards everything to its hidden
+  // prototype including own lookups.
+  //
+  // Additionally, we need to make sure that we do not cache results
+  // for objects that require access checks.
+  if (receiver_obj->IsJSObject()) {
+    if (!receiver_obj->IsJSGlobalProxy() &&
+        !receiver_obj->IsAccessCheckNeeded() && key_obj->IsName()) {
+      DisallowHeapAllocation no_allocation;
+      Handle<JSObject> receiver = Handle<JSObject>::cast(receiver_obj);
+      Handle<Name> key = Handle<Name>::cast(key_obj);
+      if (receiver->HasFastProperties()) {
+        // Attempt to use lookup cache.
+        Handle<Map> receiver_map(receiver->map(), isolate);
+        KeyedLookupCache* keyed_lookup_cache = isolate->keyed_lookup_cache();
+        int index = keyed_lookup_cache->Lookup(receiver_map, key);
+        if (index != -1) {
+          // Doubles are not cached, so raw read the value.
+          return receiver->RawFastPropertyAt(
+              FieldIndex::ForKeyedLookupCacheIndex(*receiver_map, index));
+        }
+        // Lookup cache miss.  Perform lookup and update the cache if
+        // appropriate.
+        LookupIterator it(receiver, key, LookupIterator::OWN);
+        if (it.state() == LookupIterator::DATA &&
+            it.property_details().type() == FIELD) {
+          FieldIndex field_index = it.GetFieldIndex();
+          // Do not track double fields in the keyed lookup cache. Reading
+          // double values requires boxing.
+          if (!it.representation().IsDouble()) {
+            keyed_lookup_cache->Update(receiver_map, key,
+                                       field_index.GetKeyedLookupCacheIndex());
+          }
+          AllowHeapAllocation allow_allocation;
+          return *JSObject::FastPropertyAt(receiver, it.representation(),
+                                           field_index);
+        }
+      } else {
+        // Attempt dictionary lookup.
+        NameDictionary* dictionary = receiver->property_dictionary();
+        int entry = dictionary->FindEntry(key);
+        if ((entry != NameDictionary::kNotFound) &&
+            (dictionary->DetailsAt(entry).type() == NORMAL)) {
+          Object* value = dictionary->ValueAt(entry);
+          if (!receiver->IsGlobalObject()) return value;
+          value = PropertyCell::cast(value)->value();
+          if (!value->IsTheHole()) return value;
+          // If value is the hole (meaning, absent) do the general lookup.
+        }
+      }
+    } else if (key_obj->IsSmi()) {
+      // JSObject without a name key. If the key is a Smi, check for a
+      // definite out-of-bounds access to elements, which is a strong indicator
+      // that subsequent accesses will also call the runtime. Proactively
+      // transition elements to FAST_*_ELEMENTS to avoid excessive boxing of
+      // doubles for those future calls in the case that the elements would
+      // become FAST_DOUBLE_ELEMENTS.
+      Handle<JSObject> js_object = Handle<JSObject>::cast(receiver_obj);
+      ElementsKind elements_kind = js_object->GetElementsKind();
+      if (IsFastDoubleElementsKind(elements_kind)) {
+        Handle<Smi> key = Handle<Smi>::cast(key_obj);
+        if (key->value() >= js_object->elements()->length()) {
+          if (IsFastHoleyElementsKind(elements_kind)) {
+            elements_kind = FAST_HOLEY_ELEMENTS;
+          } else {
+            elements_kind = FAST_ELEMENTS;
+          }
+          RETURN_FAILURE_ON_EXCEPTION(
+              isolate, TransitionElements(js_object, elements_kind, isolate));
+        }
+      } else {
+        DCHECK(IsFastSmiOrObjectElementsKind(elements_kind) ||
+               !IsFastElementsKind(elements_kind));
+      }
+    }
+  } else if (receiver_obj->IsString() && key_obj->IsSmi()) {
+    // Fast case for string indexing using [] with a smi index.
+    Handle<String> str = Handle<String>::cast(receiver_obj);
+    int index = args.smi_at(1);
+    if (index >= 0 && index < str->length()) {
+      return *GetCharAt(str, index);
+    }
+  }
+
+  // Fall back to GetObjectProperty.
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      Runtime::GetObjectProperty(isolate, receiver_obj, key_obj));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_AddNamedProperty) {
+  HandleScope scope(isolate);
+  RUNTIME_ASSERT(args.length() == 4);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
+  CONVERT_SMI_ARG_CHECKED(unchecked_attributes, 3);
+  RUNTIME_ASSERT(
+      (unchecked_attributes & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
+  // Compute attributes.
+  PropertyAttributes attributes =
+      static_cast<PropertyAttributes>(unchecked_attributes);
+
+#ifdef DEBUG
+  uint32_t index = 0;
+  DCHECK(!key->ToArrayIndex(&index));
+  LookupIterator it(object, key, LookupIterator::OWN_SKIP_INTERCEPTOR);
+  Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
+  if (!maybe.has_value) return isolate->heap()->exception();
+  RUNTIME_ASSERT(!it.IsFound());
+#endif
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::SetOwnPropertyIgnoreAttributes(object, key, value, attributes));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_SetProperty) {
+  HandleScope scope(isolate);
+  RUNTIME_ASSERT(args.length() == 4);
+
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
+  CONVERT_STRICT_MODE_ARG_CHECKED(strict_mode_arg, 3);
+  StrictMode strict_mode = strict_mode_arg;
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      Runtime::SetObjectProperty(isolate, object, key, value, strict_mode));
+  return *result;
+}
+
+
+// Adds an element to an array.
+// This is used to create an indexed data property into an array.
+RUNTIME_FUNCTION(Runtime_AddElement) {
+  HandleScope scope(isolate);
+  RUNTIME_ASSERT(args.length() == 4);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
+  CONVERT_SMI_ARG_CHECKED(unchecked_attributes, 3);
+  RUNTIME_ASSERT(
+      (unchecked_attributes & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
+  // Compute attributes.
+  PropertyAttributes attributes =
+      static_cast<PropertyAttributes>(unchecked_attributes);
+
+  uint32_t index = 0;
+  key->ToArrayIndex(&index);
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, JSObject::SetElement(object, index, value, attributes,
+                                            SLOPPY, false, DEFINE_PROPERTY));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_DeleteProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 3);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
+  CONVERT_STRICT_MODE_ARG_CHECKED(strict_mode, 2);
+  JSReceiver::DeleteMode delete_mode = strict_mode == STRICT
+                                           ? JSReceiver::STRICT_DELETION
+                                           : JSReceiver::NORMAL_DELETION;
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, JSReceiver::DeleteProperty(object, key, delete_mode));
+  return *result;
+}
+
+
+static Object* HasOwnPropertyImplementation(Isolate* isolate,
+                                            Handle<JSObject> object,
+                                            Handle<Name> key) {
+  Maybe<bool> maybe = JSReceiver::HasOwnProperty(object, key);
+  if (!maybe.has_value) return isolate->heap()->exception();
+  if (maybe.value) return isolate->heap()->true_value();
+  // Handle hidden prototypes.  If there's a hidden prototype above this thing
+  // then we have to check it for properties, because they are supposed to
+  // look like they are on this object.
+  PrototypeIterator iter(isolate, object);
+  if (!iter.IsAtEnd() &&
+      Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter))
+          ->map()
+          ->is_hidden_prototype()) {
+    // TODO(verwaest): The recursion is not necessary for keys that are array
+    // indices. Removing this.
+    return HasOwnPropertyImplementation(
+        isolate, Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter)),
+        key);
+  }
+  RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+  return isolate->heap()->false_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_HasOwnProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0)
+  CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
+
+  uint32_t index;
+  const bool key_is_array_index = key->AsArrayIndex(&index);
+
+  // Only JS objects can have properties.
+  if (object->IsJSObject()) {
+    Handle<JSObject> js_obj = Handle<JSObject>::cast(object);
+    // Fast case: either the key is a real named property or it is not
+    // an array index and there are no interceptors or hidden
+    // prototypes.
+    Maybe<bool> maybe = JSObject::HasRealNamedProperty(js_obj, key);
+    if (!maybe.has_value) return isolate->heap()->exception();
+    DCHECK(!isolate->has_pending_exception());
+    if (maybe.value) {
+      return isolate->heap()->true_value();
+    }
+    Map* map = js_obj->map();
+    if (!key_is_array_index && !map->has_named_interceptor() &&
+        !HeapObject::cast(map->prototype())->map()->is_hidden_prototype()) {
+      return isolate->heap()->false_value();
+    }
+    // Slow case.
+    return HasOwnPropertyImplementation(isolate, Handle<JSObject>(js_obj),
+                                        Handle<Name>(key));
+  } else if (object->IsString() && key_is_array_index) {
+    // Well, there is one exception:  Handle [] on strings.
+    Handle<String> string = Handle<String>::cast(object);
+    if (index < static_cast<uint32_t>(string->length())) {
+      return isolate->heap()->true_value();
+    }
+  }
+  return isolate->heap()->false_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_HasProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
+
+  Maybe<bool> maybe = JSReceiver::HasProperty(receiver, key);
+  if (!maybe.has_value) return isolate->heap()->exception();
+  return isolate->heap()->ToBoolean(maybe.value);
+}
+
+
+RUNTIME_FUNCTION(Runtime_HasElement) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0);
+  CONVERT_SMI_ARG_CHECKED(index, 1);
+
+  Maybe<bool> maybe = JSReceiver::HasElement(receiver, index);
+  if (!maybe.has_value) return isolate->heap()->exception();
+  return isolate->heap()->ToBoolean(maybe.value);
+}
+
+
+RUNTIME_FUNCTION(Runtime_IsPropertyEnumerable) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
+
+  Maybe<PropertyAttributes> maybe =
+      JSReceiver::GetOwnPropertyAttributes(object, key);
+  if (!maybe.has_value) return isolate->heap()->exception();
+  if (maybe.value == ABSENT) maybe.value = DONT_ENUM;
+  return isolate->heap()->ToBoolean((maybe.value & DONT_ENUM) == 0);
+}
+
+
+RUNTIME_FUNCTION(Runtime_GetPropertyNames) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, object, 0);
+  Handle<JSArray> result;
+
+  isolate->counters()->for_in()->Increment();
+  Handle<FixedArray> elements;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, elements,
+      JSReceiver::GetKeys(object, JSReceiver::INCLUDE_PROTOS));
+  return *isolate->factory()->NewJSArrayWithElements(elements);
+}
+
+
+// Returns either a FixedArray as Runtime_GetPropertyNames,
+// or, if the given object has an enum cache that contains
+// all enumerable properties of the object and its prototypes
+// have none, the map of the object. This is used to speed up
+// the check for deletions during a for-in.
+RUNTIME_FUNCTION(Runtime_GetPropertyNamesFast) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+
+  CONVERT_ARG_CHECKED(JSReceiver, raw_object, 0);
+
+  if (raw_object->IsSimpleEnum()) return raw_object->map();
+
+  HandleScope scope(isolate);
+  Handle<JSReceiver> object(raw_object);
+  Handle<FixedArray> content;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, content,
+      JSReceiver::GetKeys(object, JSReceiver::INCLUDE_PROTOS));
+
+  // Test again, since cache may have been built by preceding call.
+  if (object->IsSimpleEnum()) return object->map();
+
+  return *content;
+}
+
+
+// Find the length of the prototype chain that is to be handled as one. If a
+// prototype object is hidden it is to be viewed as part of the the object it
+// is prototype for.
+static int OwnPrototypeChainLength(JSObject* obj) {
+  int count = 1;
+  for (PrototypeIterator iter(obj->GetIsolate(), obj);
+       !iter.IsAtEnd(PrototypeIterator::END_AT_NON_HIDDEN); iter.Advance()) {
+    count++;
+  }
+  return count;
+}
+
+
+// Return the names of the own named properties.
+// args[0]: object
+// args[1]: PropertyAttributes as int
+RUNTIME_FUNCTION(Runtime_GetOwnPropertyNames) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  if (!args[0]->IsJSObject()) {
+    return isolate->heap()->undefined_value();
+  }
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+  CONVERT_SMI_ARG_CHECKED(filter_value, 1);
+  PropertyAttributes filter = static_cast<PropertyAttributes>(filter_value);
+
+  // Skip the global proxy as it has no properties and always delegates to the
+  // real global object.
+  if (obj->IsJSGlobalProxy()) {
+    // Only collect names if access is permitted.
+    if (obj->IsAccessCheckNeeded() &&
+        !isolate->MayNamedAccess(obj, isolate->factory()->undefined_value(),
+                                 v8::ACCESS_KEYS)) {
+      isolate->ReportFailedAccessCheck(obj, v8::ACCESS_KEYS);
+      RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+      return *isolate->factory()->NewJSArray(0);
+    }
+    PrototypeIterator iter(isolate, obj);
+    obj = Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter));
+  }
+
+  // Find the number of objects making up this.
+  int length = OwnPrototypeChainLength(*obj);
+
+  // Find the number of own properties for each of the objects.
+  ScopedVector<int> own_property_count(length);
+  int total_property_count = 0;
+  {
+    PrototypeIterator iter(isolate, obj, PrototypeIterator::START_AT_RECEIVER);
+    for (int i = 0; i < length; i++) {
+      DCHECK(!iter.IsAtEnd());
+      Handle<JSObject> jsproto =
+          Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter));
+      // Only collect names if access is permitted.
+      if (jsproto->IsAccessCheckNeeded() &&
+          !isolate->MayNamedAccess(jsproto,
+                                   isolate->factory()->undefined_value(),
+                                   v8::ACCESS_KEYS)) {
+        isolate->ReportFailedAccessCheck(jsproto, v8::ACCESS_KEYS);
+        RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+        return *isolate->factory()->NewJSArray(0);
+      }
+      int n;
+      n = jsproto->NumberOfOwnProperties(filter);
+      own_property_count[i] = n;
+      total_property_count += n;
+      iter.Advance();
+    }
+  }
+
+  // Allocate an array with storage for all the property names.
+  Handle<FixedArray> names =
+      isolate->factory()->NewFixedArray(total_property_count);
+
+  // Get the property names.
+  int next_copy_index = 0;
+  int hidden_strings = 0;
+  {
+    PrototypeIterator iter(isolate, obj, PrototypeIterator::START_AT_RECEIVER);
+    for (int i = 0; i < length; i++) {
+      DCHECK(!iter.IsAtEnd());
+      Handle<JSObject> jsproto =
+          Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter));
+      jsproto->GetOwnPropertyNames(*names, next_copy_index, filter);
+      if (i > 0) {
+        // Names from hidden prototypes may already have been added
+        // for inherited function template instances. Count the duplicates
+        // and stub them out; the final copy pass at the end ignores holes.
+        for (int j = next_copy_index;
+             j < next_copy_index + own_property_count[i]; j++) {
+          Object* name_from_hidden_proto = names->get(j);
+          for (int k = 0; k < next_copy_index; k++) {
+            if (names->get(k) != isolate->heap()->hidden_string()) {
+              Object* name = names->get(k);
+              if (name_from_hidden_proto == name) {
+                names->set(j, isolate->heap()->hidden_string());
+                hidden_strings++;
+                break;
+              }
+            }
+          }
+        }
+      }
+      next_copy_index += own_property_count[i];
+
+      // Hidden properties only show up if the filter does not skip strings.
+      if ((filter & STRING) == 0 && JSObject::HasHiddenProperties(jsproto)) {
+        hidden_strings++;
+      }
+      iter.Advance();
+    }
+  }
+
+  // Filter out name of hidden properties object and
+  // hidden prototype duplicates.
+  if (hidden_strings > 0) {
+    Handle<FixedArray> old_names = names;
+    names = isolate->factory()->NewFixedArray(names->length() - hidden_strings);
+    int dest_pos = 0;
+    for (int i = 0; i < total_property_count; i++) {
+      Object* name = old_names->get(i);
+      if (name == isolate->heap()->hidden_string()) {
+        hidden_strings--;
+        continue;
+      }
+      names->set(dest_pos++, name);
+    }
+    DCHECK_EQ(0, hidden_strings);
+  }
+
+  return *isolate->factory()->NewJSArrayWithElements(names);
+}
+
+
+// Return the names of the own indexed properties.
+// args[0]: object
+RUNTIME_FUNCTION(Runtime_GetOwnElementNames) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  if (!args[0]->IsJSObject()) {
+    return isolate->heap()->undefined_value();
+  }
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+
+  int n = obj->NumberOfOwnElements(static_cast<PropertyAttributes>(NONE));
+  Handle<FixedArray> names = isolate->factory()->NewFixedArray(n);
+  obj->GetOwnElementKeys(*names, static_cast<PropertyAttributes>(NONE));
+  return *isolate->factory()->NewJSArrayWithElements(names);
+}
+
+
+// Return information on whether an object has a named or indexed interceptor.
+// args[0]: object
+RUNTIME_FUNCTION(Runtime_GetInterceptorInfo) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  if (!args[0]->IsJSObject()) {
+    return Smi::FromInt(0);
+  }
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+
+  int result = 0;
+  if (obj->HasNamedInterceptor()) result |= 2;
+  if (obj->HasIndexedInterceptor()) result |= 1;
+
+  return Smi::FromInt(result);
+}
+
+
+// Return property names from named interceptor.
+// args[0]: object
+RUNTIME_FUNCTION(Runtime_GetNamedInterceptorPropertyNames) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+
+  if (obj->HasNamedInterceptor()) {
+    Handle<JSObject> result;
+    if (JSObject::GetKeysForNamedInterceptor(obj, obj).ToHandle(&result)) {
+      return *result;
+    }
+  }
+  return isolate->heap()->undefined_value();
+}
+
+
+// Return element names from indexed interceptor.
+// args[0]: object
+RUNTIME_FUNCTION(Runtime_GetIndexedInterceptorElementNames) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+
+  if (obj->HasIndexedInterceptor()) {
+    Handle<JSObject> result;
+    if (JSObject::GetKeysForIndexedInterceptor(obj, obj).ToHandle(&result)) {
+      return *result;
+    }
+  }
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_OwnKeys) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSObject, raw_object, 0);
+  Handle<JSObject> object(raw_object);
+
+  if (object->IsJSGlobalProxy()) {
+    // Do access checks before going to the global object.
+    if (object->IsAccessCheckNeeded() &&
+        !isolate->MayNamedAccess(object, isolate->factory()->undefined_value(),
+                                 v8::ACCESS_KEYS)) {
+      isolate->ReportFailedAccessCheck(object, v8::ACCESS_KEYS);
+      RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+      return *isolate->factory()->NewJSArray(0);
+    }
+
+    PrototypeIterator iter(isolate, object);
+    // If proxy is detached we simply return an empty array.
+    if (iter.IsAtEnd()) return *isolate->factory()->NewJSArray(0);
+    object = Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter));
+  }
+
+  Handle<FixedArray> contents;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, contents, JSReceiver::GetKeys(object, JSReceiver::OWN_ONLY));
+
+  // Some fast paths through GetKeysInFixedArrayFor reuse a cached
+  // property array and since the result is mutable we have to create
+  // a fresh clone on each invocation.
+  int length = contents->length();
+  Handle<FixedArray> copy = isolate->factory()->NewFixedArray(length);
+  for (int i = 0; i < length; i++) {
+    Object* entry = contents->get(i);
+    if (entry->IsString()) {
+      copy->set(i, entry);
+    } else {
+      DCHECK(entry->IsNumber());
+      HandleScope scope(isolate);
+      Handle<Object> entry_handle(entry, isolate);
+      Handle<Object> entry_str =
+          isolate->factory()->NumberToString(entry_handle);
+      copy->set(i, *entry_str);
+    }
+  }
+  return *isolate->factory()->NewJSArrayWithElements(copy);
+}
+
+
+RUNTIME_FUNCTION(Runtime_ToFastProperties) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  if (object->IsJSObject() && !object->IsGlobalObject()) {
+    JSObject::MigrateSlowToFast(Handle<JSObject>::cast(object), 0);
+  }
+  return *object;
+}
+
+
+RUNTIME_FUNCTION(Runtime_ToBool) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, object, 0);
+
+  return isolate->heap()->ToBoolean(object->BooleanValue());
+}
+
+
+// Returns the type string of a value; see ECMA-262, 11.4.3 (p 47).
+// Possible optimizations: put the type string into the oddballs.
+RUNTIME_FUNCTION(Runtime_Typeof) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  if (obj->IsNumber()) return isolate->heap()->number_string();
+  HeapObject* heap_obj = HeapObject::cast(obj);
+
+  // typeof an undetectable object is 'undefined'
+  if (heap_obj->map()->is_undetectable()) {
+    return isolate->heap()->undefined_string();
+  }
+
+  InstanceType instance_type = heap_obj->map()->instance_type();
+  if (instance_type < FIRST_NONSTRING_TYPE) {
+    return isolate->heap()->string_string();
+  }
+
+  switch (instance_type) {
+    case ODDBALL_TYPE:
+      if (heap_obj->IsTrue() || heap_obj->IsFalse()) {
+        return isolate->heap()->boolean_string();
+      }
+      if (heap_obj->IsNull()) {
+        return isolate->heap()->object_string();
+      }
+      DCHECK(heap_obj->IsUndefined());
+      return isolate->heap()->undefined_string();
+    case SYMBOL_TYPE:
+      return isolate->heap()->symbol_string();
+    case JS_FUNCTION_TYPE:
+    case JS_FUNCTION_PROXY_TYPE:
+      return isolate->heap()->function_string();
+    default:
+      // For any kind of object not handled above, the spec rule for
+      // host objects gives that it is okay to return "object"
+      return isolate->heap()->object_string();
+  }
+}
+
+
+RUNTIME_FUNCTION(Runtime_Booleanize) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_CHECKED(Object, value_raw, 0);
+  CONVERT_SMI_ARG_CHECKED(token_raw, 1);
+  intptr_t value = reinterpret_cast<intptr_t>(value_raw);
+  Token::Value token = static_cast<Token::Value>(token_raw);
+  switch (token) {
+    case Token::EQ:
+    case Token::EQ_STRICT:
+      return isolate->heap()->ToBoolean(value == 0);
+    case Token::NE:
+    case Token::NE_STRICT:
+      return isolate->heap()->ToBoolean(value != 0);
+    case Token::LT:
+      return isolate->heap()->ToBoolean(value < 0);
+    case Token::GT:
+      return isolate->heap()->ToBoolean(value > 0);
+    case Token::LTE:
+      return isolate->heap()->ToBoolean(value <= 0);
+    case Token::GTE:
+      return isolate->heap()->ToBoolean(value >= 0);
+    default:
+      // This should only happen during natives fuzzing.
+      return isolate->heap()->undefined_value();
+  }
+}
+
+
+RUNTIME_FUNCTION(Runtime_NewStringWrapper) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(String, value, 0);
+  return *Object::ToObject(isolate, value).ToHandleChecked();
+}
+
+
+RUNTIME_FUNCTION(Runtime_AllocateHeapNumber) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 0);
+  return *isolate->factory()->NewHeapNumber(0);
+}
+
+
+static Object* Runtime_NewObjectHelper(Isolate* isolate,
+                                       Handle<Object> constructor,
+                                       Handle<AllocationSite> site) {
+  // If the constructor isn't a proper function we throw a type error.
+  if (!constructor->IsJSFunction()) {
+    Vector<Handle<Object> > arguments = HandleVector(&constructor, 1);
+    THROW_NEW_ERROR_RETURN_FAILURE(isolate,
+                                   NewTypeError("not_constructor", arguments));
+  }
+
+  Handle<JSFunction> function = Handle<JSFunction>::cast(constructor);
+
+  // If function should not have prototype, construction is not allowed. In this
+  // case generated code bailouts here, since function has no initial_map.
+  if (!function->should_have_prototype() && !function->shared()->bound()) {
+    Vector<Handle<Object> > arguments = HandleVector(&constructor, 1);
+    THROW_NEW_ERROR_RETURN_FAILURE(isolate,
+                                   NewTypeError("not_constructor", arguments));
+  }
+
+  Debug* debug = isolate->debug();
+  // Handle stepping into constructors if step into is active.
+  if (debug->StepInActive()) {
+    debug->HandleStepIn(function, Handle<Object>::null(), 0, true);
+  }
+
+  if (function->has_initial_map()) {
+    if (function->initial_map()->instance_type() == JS_FUNCTION_TYPE) {
+      // The 'Function' function ignores the receiver object when
+      // called using 'new' and creates a new JSFunction object that
+      // is returned.  The receiver object is only used for error
+      // reporting if an error occurs when constructing the new
+      // JSFunction. Factory::NewJSObject() should not be used to
+      // allocate JSFunctions since it does not properly initialize
+      // the shared part of the function. Since the receiver is
+      // ignored anyway, we use the global object as the receiver
+      // instead of a new JSFunction object. This way, errors are
+      // reported the same way whether or not 'Function' is called
+      // using 'new'.
+      return isolate->global_proxy();
+    }
+  }
+
+  // The function should be compiled for the optimization hints to be
+  // available.
+  Compiler::EnsureCompiled(function, CLEAR_EXCEPTION);
+
+  Handle<JSObject> result;
+  if (site.is_null()) {
+    result = isolate->factory()->NewJSObject(function);
+  } else {
+    result = isolate->factory()->NewJSObjectWithMemento(function, site);
+  }
+
+  isolate->counters()->constructed_objects()->Increment();
+  isolate->counters()->constructed_objects_runtime()->Increment();
+
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_NewObject) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, constructor, 0);
+  return Runtime_NewObjectHelper(isolate, constructor,
+                                 Handle<AllocationSite>::null());
+}
+
+
+RUNTIME_FUNCTION(Runtime_NewObjectWithAllocationSite) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, constructor, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, feedback, 0);
+  Handle<AllocationSite> site;
+  if (feedback->IsAllocationSite()) {
+    // The feedback can be an AllocationSite or undefined.
+    site = Handle<AllocationSite>::cast(feedback);
+  }
+  return Runtime_NewObjectHelper(isolate, constructor, site);
+}
+
+
+RUNTIME_FUNCTION(Runtime_FinalizeInstanceSize) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
+  function->CompleteInobjectSlackTracking();
+
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_GlobalProxy) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, global, 0);
+  if (!global->IsJSGlobalObject()) return isolate->heap()->null_value();
+  return JSGlobalObject::cast(global)->global_proxy();
+}
+
+
+RUNTIME_FUNCTION(Runtime_IsAttachedGlobal) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, global, 0);
+  if (!global->IsJSGlobalObject()) return isolate->heap()->false_value();
+  return isolate->heap()->ToBoolean(
+      !JSGlobalObject::cast(global)->IsDetached());
+}
+
+
+RUNTIME_FUNCTION(Runtime_LookupAccessor) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 3);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
+  CONVERT_SMI_ARG_CHECKED(flag, 2);
+  AccessorComponent component = flag == 0 ? ACCESSOR_GETTER : ACCESSOR_SETTER;
+  if (!receiver->IsJSObject()) return isolate->heap()->undefined_value();
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::GetAccessor(Handle<JSObject>::cast(receiver), name, component));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_LoadMutableDouble) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Smi, index, 1);
+  RUNTIME_ASSERT((index->value() & 1) == 1);
+  FieldIndex field_index =
+      FieldIndex::ForLoadByFieldIndex(object->map(), index->value());
+  if (field_index.is_inobject()) {
+    RUNTIME_ASSERT(field_index.property_index() <
+                   object->map()->inobject_properties());
+  } else {
+    RUNTIME_ASSERT(field_index.outobject_array_index() <
+                   object->properties()->length());
+  }
+  Handle<Object> raw_value(object->RawFastPropertyAt(field_index), isolate);
+  RUNTIME_ASSERT(raw_value->IsMutableHeapNumber());
+  return *Object::WrapForRead(isolate, raw_value, Representation::Double());
+}
+
+
+RUNTIME_FUNCTION(Runtime_TryMigrateInstance) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  if (!object->IsJSObject()) return Smi::FromInt(0);
+  Handle<JSObject> js_object = Handle<JSObject>::cast(object);
+  if (!js_object->map()->is_deprecated()) return Smi::FromInt(0);
+  // This call must not cause lazy deopts, because it's called from deferred
+  // code where we can't handle lazy deopts for lack of a suitable bailout
+  // ID. So we just try migration and signal failure if necessary,
+  // which will also trigger a deopt.
+  if (!JSObject::TryMigrateInstance(js_object)) return Smi::FromInt(0);
+  return *object;
+}
+
+
+RUNTIME_FUNCTION(Runtime_IsJSGlobalProxy) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  return isolate->heap()->ToBoolean(obj->IsJSGlobalProxy());
+}
+
+
+static bool IsValidAccessor(Handle<Object> obj) {
+  return obj->IsUndefined() || obj->IsSpecFunction() || obj->IsNull();
+}
+
+
+// Implements part of 8.12.9 DefineOwnProperty.
+// There are 3 cases that lead here:
+// Step 4b - define a new accessor property.
+// Steps 9c & 12 - replace an existing data property with an accessor property.
+// Step 12 - update an existing accessor property with an accessor or generic
+//           descriptor.
+RUNTIME_FUNCTION(Runtime_DefineAccessorPropertyUnchecked) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 5);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, obj, 0);
+  RUNTIME_ASSERT(!obj->IsNull());
+  CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, getter, 2);
+  RUNTIME_ASSERT(IsValidAccessor(getter));
+  CONVERT_ARG_HANDLE_CHECKED(Object, setter, 3);
+  RUNTIME_ASSERT(IsValidAccessor(setter));
+  CONVERT_SMI_ARG_CHECKED(unchecked, 4);
+  RUNTIME_ASSERT((unchecked & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
+  PropertyAttributes attr = static_cast<PropertyAttributes>(unchecked);
+
+  bool fast = obj->HasFastProperties();
+  RETURN_FAILURE_ON_EXCEPTION(
+      isolate, JSObject::DefineAccessor(obj, name, getter, setter, attr));
+  if (fast) JSObject::MigrateSlowToFast(obj, 0);
+  return isolate->heap()->undefined_value();
+}
+
+
+// Implements part of 8.12.9 DefineOwnProperty.
+// There are 3 cases that lead here:
+// Step 4a - define a new data property.
+// Steps 9b & 12 - replace an existing accessor property with a data property.
+// Step 12 - update an existing data property with a data or generic
+//           descriptor.
+RUNTIME_FUNCTION(Runtime_DefineDataPropertyUnchecked) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 4);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, js_object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, obj_value, 2);
+  CONVERT_SMI_ARG_CHECKED(unchecked, 3);
+  RUNTIME_ASSERT((unchecked & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
+  PropertyAttributes attr = static_cast<PropertyAttributes>(unchecked);
+
+  LookupIterator it(js_object, name, LookupIterator::OWN_SKIP_INTERCEPTOR);
+  if (it.IsFound() && it.state() == LookupIterator::ACCESS_CHECK) {
+    if (!isolate->MayNamedAccess(js_object, name, v8::ACCESS_SET)) {
+      return isolate->heap()->undefined_value();
+    }
+    it.Next();
+  }
+
+  // Take special care when attributes are different and there is already
+  // a property.
+  if (it.state() == LookupIterator::ACCESSOR) {
+    // Use IgnoreAttributes version since a readonly property may be
+    // overridden and SetProperty does not allow this.
+    Handle<Object> result;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, result,
+        JSObject::SetOwnPropertyIgnoreAttributes(
+            js_object, name, obj_value, attr, JSObject::DONT_FORCE_FIELD));
+    return *result;
+  }
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      Runtime::DefineObjectProperty(js_object, name, obj_value, attr));
+  return *result;
+}
+
+
+// Return property without being observable by accessors or interceptors.
+RUNTIME_FUNCTION(Runtime_GetDataProperty) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
+  return *JSObject::GetDataProperty(object, key);
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_ValueOf) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  if (!obj->IsJSValue()) return obj;
+  return JSValue::cast(obj)->value();
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_SetValueOf) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  CONVERT_ARG_CHECKED(Object, value, 1);
+  if (!obj->IsJSValue()) return value;
+  JSValue::cast(obj)->set_value(value);
+  return value;
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_ObjectEquals) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_CHECKED(Object, obj1, 0);
+  CONVERT_ARG_CHECKED(Object, obj2, 1);
+  return isolate->heap()->ToBoolean(obj1 == obj2);
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_IsObject) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  if (!obj->IsHeapObject()) return isolate->heap()->false_value();
+  if (obj->IsNull()) return isolate->heap()->true_value();
+  if (obj->IsUndetectableObject()) return isolate->heap()->false_value();
+  Map* map = HeapObject::cast(obj)->map();
+  bool is_non_callable_spec_object =
+      map->instance_type() >= FIRST_NONCALLABLE_SPEC_OBJECT_TYPE &&
+      map->instance_type() <= LAST_NONCALLABLE_SPEC_OBJECT_TYPE;
+  return isolate->heap()->ToBoolean(is_non_callable_spec_object);
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_IsUndetectableObject) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  return isolate->heap()->ToBoolean(obj->IsUndetectableObject());
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_IsSpecObject) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  return isolate->heap()->ToBoolean(obj->IsSpecObject());
+}
+
+
+RUNTIME_FUNCTION(RuntimeReference_ClassOf) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  if (!obj->IsJSReceiver()) return isolate->heap()->null_value();
+  return JSReceiver::cast(obj)->class_name();
+}
+}
+}  // namespace v8::internal

src/runtime/runtime-strings.cc

@@ -1256,5 +1256,11 @@ RUNTIME_FUNCTION(RuntimeReference_StringAdd) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_StringAdd(args, isolate);
 }
+
+
+RUNTIME_FUNCTION(RuntimeReference_IsStringWrapperSafeForDefaultValueOf) {
+  UNIMPLEMENTED();
+  return NULL;
+}
 }
 }  // namespace v8::internal

tools/gyp/v8.gyp

@@ -736,6 +736,8 @@
         '../../src/rewriter.h',
         '../../src/runtime-profiler.cc',
         '../../src/runtime-profiler.h',
+        '../../src/runtime/runtime-api.cc',
+        '../../src/runtime/runtime-array.cc',
         '../../src/runtime/runtime-classes.cc',
         '../../src/runtime/runtime-collections.cc',
         '../../src/runtime/runtime-compiler.cc',
@@ -744,11 +746,13 @@
         '../../src/runtime/runtime-function.cc',
         '../../src/runtime/runtime-generator.cc',
         '../../src/runtime/runtime-i18n.cc',
+        '../../src/runtime/runtime-internal.cc',
         '../../src/runtime/runtime-json.cc',
         '../../src/runtime/runtime-literals.cc',
         '../../src/runtime/runtime-liveedit.cc',
         '../../src/runtime/runtime-maths.cc',
         '../../src/runtime/runtime-numbers.cc',
+        '../../src/runtime/runtime-object.cc',
         '../../src/runtime/runtime-observe.cc',
         '../../src/runtime/runtime-proxy.cc',
         '../../src/runtime/runtime-regexp.cc',