Speed up the LookupIterator

src/lookup.h

 // 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.
 
 #ifndef V8_LOOKUP_H_
 #define V8_LOOKUP_H_
 
 #include "src/factory.h"
 #include "src/isolate.h"
 #include "src/objects.h"
@@ skipping 29 matching lines @@
     DATA,
     TRANSITION,
     // Set state_ to BEFORE_PROPERTY to ensure that the next lookup will be a
     // PROPERTY lookup.
     BEFORE_PROPERTY = INTERCEPTOR
   };
 
   LookupIterator(Handle<Object> receiver, Handle<Name> name,
                  Configuration configuration = DEFAULT)
       : configuration_(ComputeConfiguration(configuration, name)),
-        state_(NOT_FOUND),
         interceptor_state_(InterceptorState::kUninitialized),
         property_details_(PropertyDetails::Empty()),
         isolate_(name->GetIsolate()),
         name_(isolate_->factory()->InternalizeName(name)),
         // kMaxUInt32 isn't a valid index.
         index_(kMaxUInt32),
         receiver_(receiver),
-        holder_(GetRoot(isolate_, receiver)),
-        initial_holder_(holder_),
-        number_(DescriptorArray::kNotFound) {
+        initial_holder_(GetRoot(isolate_, receiver)) {
 #ifdef DEBUG
     uint32_t index;  // Assert that the name is not an array index.
     DCHECK(!name->AsArrayIndex(&index));
 #endif  // DEBUG
-    Next();
+    Start();
   }
 
   LookupIterator(Handle<Object> receiver, Handle<Name> name,
                  Handle<JSReceiver> holder,
                  Configuration configuration = DEFAULT)
       : configuration_(ComputeConfiguration(configuration, name)),
-        state_(NOT_FOUND),
         interceptor_state_(InterceptorState::kUninitialized),
         property_details_(PropertyDetails::Empty()),
         isolate_(name->GetIsolate()),
         name_(isolate_->factory()->InternalizeName(name)),
         // kMaxUInt32 isn't a valid index.
         index_(kMaxUInt32),
         receiver_(receiver),
-        holder_(holder),
-        initial_holder_(holder_),
-        number_(DescriptorArray::kNotFound) {
+        initial_holder_(holder) {
 #ifdef DEBUG
     uint32_t index;  // Assert that the name is not an array index.
     DCHECK(!name->AsArrayIndex(&index));
 #endif  // DEBUG
-    Next();
+    Start();
   }
 
   LookupIterator(Isolate* isolate, Handle<Object> receiver, uint32_t index,
                  Configuration configuration = DEFAULT)
       : configuration_(configuration),
-        state_(NOT_FOUND),
         interceptor_state_(InterceptorState::kUninitialized),
         property_details_(PropertyDetails::Empty()),
         isolate_(isolate),
         name_(),
         index_(index),
         receiver_(receiver),
-        holder_(GetRoot(isolate, receiver, index)),
-        initial_holder_(holder_),
-        number_(DescriptorArray::kNotFound) {
+        initial_holder_(GetRoot(isolate, receiver, index)) {
     // kMaxUInt32 isn't a valid index.
     DCHECK_NE(kMaxUInt32, index_);
-    Next();
+    Start();
   }
 
   LookupIterator(Isolate* isolate, Handle<Object> receiver, uint32_t index,
                  Handle<JSReceiver> holder,
                  Configuration configuration = DEFAULT)
       : configuration_(configuration),
-        state_(NOT_FOUND),
         interceptor_state_(InterceptorState::kUninitialized),
         property_details_(PropertyDetails::Empty()),
         isolate_(isolate),
         name_(),
         index_(index),
         receiver_(receiver),
-        holder_(holder),
-        initial_holder_(holder_),
-        number_(DescriptorArray::kNotFound) {
+        initial_holder_(holder) {
     // kMaxUInt32 isn't a valid index.
     DCHECK_NE(kMaxUInt32, index_);
-    Next();
+    Start();
   }
 
   static LookupIterator PropertyOrElement(
       Isolate* isolate, Handle<Object> receiver, Handle<Name> name,
       Configuration configuration = DEFAULT) {
     uint32_t index;
     if (name->AsArrayIndex(&index)) {
       LookupIterator it =
           LookupIterator(isolate, receiver, index, configuration);
       it.name_ = name;
@@ skipping 42 matching lines @@
   bool IsFound() const { return state_ != NOT_FOUND; }
   void Next();
   void NotFound() {
     has_property_ = false;
     state_ = NOT_FOUND;
   }
 
   Heap* heap() const { return isolate_->heap(); }
   Factory* factory() const { return isolate_->factory(); }
   Handle<Object> GetReceiver() const { return receiver_; }
-  Handle<JSObject> GetStoreTarget() const;
+
+  Handle<JSObject> GetStoreTarget() const {
+    if (receiver_->IsJSGlobalProxy()) {
+      Map* map = JSGlobalProxy::cast(*receiver_)->map();
+      if (map->has_hidden_prototype()) {
+        return handle(JSGlobalObject::cast(map->prototype()), isolate_);
+      }
+    }
+    return Handle<JSObject>::cast(receiver_);
+  }
+
   bool is_dictionary_holder() const { return !holder_->HasFastProperties(); }
   Handle<Map> transition_map() const {
     DCHECK_EQ(TRANSITION, state_);
     return Handle<Map>::cast(transition_);
   }
   template <class T>
   Handle<T> GetHolder() const {
     DCHECK(IsFound());
     return Handle<T>::cast(holder_);
   }
@@ skipping 54 matching lines @@
   Handle<Object> GetAccessors() const;
   inline Handle<InterceptorInfo> GetInterceptor() const {
     DCHECK_EQ(INTERCEPTOR, state_);
     return handle(GetInterceptor(JSObject::cast(*holder_)), isolate_);
   }
   Handle<Object> GetDataValue() const;
   void WriteDataValue(Handle<Object> value);
   void UpdateProtector();
 
  private:
+  void Start();
+  void NextInternal(Map* map, JSReceiver* holder);
+
   enum class InterceptorState {
     kUninitialized,
     kSkipNonMasking,
     kProcessNonMasking
   };
 
   Handle<Map> GetReceiverMap() const;
 
   MUST_USE_RESULT inline JSReceiver* NextHolder(Map* map);
-  inline State LookupInHolder(Map* map, JSReceiver* holder);
+  inline State LookupInHolder(Map* map, JSReceiver* holder) {
+    return map->instance_type() <= LAST_SPECIAL_RECEIVER_TYPE
+               ? LookupInSpecialHolder(map, holder)
+               : LookupInRegularHolder(map, holder);
+  }
+  State LookupInRegularHolder(Map* map, JSReceiver* holder);
+  State LookupInSpecialHolder(Map* map, JSReceiver* holder);
   void RestartLookupForNonMaskingInterceptors() {
     RestartInternal(InterceptorState::kProcessNonMasking);
   }
   void RestartInternal(InterceptorState interceptor_state);
-  State LookupNonMaskingInterceptorInHolder(Map* map, JSReceiver* holder);
   Handle<Object> FetchValue() const;
   void ReloadPropertyInformation();
   inline bool SkipInterceptor(JSObject* holder);
   bool HasInterceptor(Map* map) const;
   inline InterceptorInfo* GetInterceptor(JSObject* holder) const {
     if (IsElement()) return holder->GetIndexedInterceptor();
     return holder->GetNamedInterceptor();
   }
 
   bool check_hidden() const { return (configuration_ & kHidden) != 0; }
@@ skipping 51 matching lines @@
   Handle<JSReceiver> holder_;
   const Handle<JSReceiver> initial_holder_;
   uint32_t number_;
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_LOOKUP_H_