Get rid of special property_encoding flag on 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 25 matching lines @@
     NOT_FOUND,
     UNKNOWN,  // Dictionary-mode holder map without a holder.
     ACCESSOR,
     DATA,
     TRANSITION,
     // Set state_ to BEFORE_PROPERTY to ensure that the next lookup will be a
     // PROPERTY lookup.
     BEFORE_PROPERTY = INTERCEPTOR
   };
 
-  enum PropertyEncoding {
-    DICTIONARY,
-    DESCRIPTOR
-  };
-
   LookupIterator(Handle<Object> receiver, Handle<Name> name,
                  Configuration configuration = PROTOTYPE_CHAIN)
       : configuration_(ComputeConfiguration(configuration, name)),
         state_(NOT_FOUND),
-        property_encoding_(DESCRIPTOR),
         property_details_(NONE, NORMAL, Representation::None()),
         isolate_(name->GetIsolate()),
         name_(name),
         maybe_receiver_(receiver),
         number_(DescriptorArray::kNotFound) {
     Handle<JSReceiver> root = GetRoot();
     holder_map_ = handle(root->map(), isolate_);
     maybe_holder_ = root;
     Next();
   }
 
   LookupIterator(Handle<Object> receiver, Handle<Name> name,
                  Handle<JSReceiver> holder,
                  Configuration configuration = PROTOTYPE_CHAIN)
       : configuration_(ComputeConfiguration(configuration, name)),
         state_(NOT_FOUND),
-        property_encoding_(DESCRIPTOR),
         property_details_(NONE, NORMAL, Representation::None()),
         isolate_(name->GetIsolate()),
         name_(name),
         holder_map_(holder->map(), isolate_),
         maybe_receiver_(receiver),
         maybe_holder_(holder),
         number_(DescriptorArray::kNotFound) {
     Next();
   }
 
   Isolate* isolate() const { return isolate_; }
   State state() const { return state_; }
   Handle<Name> name() const { return name_; }
 
   bool IsFound() const { return state_ != NOT_FOUND; }
   void Next();
   void NotFound() {
     has_property_ = false;
     state_ = NOT_FOUND;
   }
 
   Factory* factory() const { return isolate_->factory(); }
   Handle<Object> GetReceiver() const {
     return maybe_receiver_.ToHandleChecked();
   }
   Handle<JSObject> GetStoreTarget() const;
-  Handle<Map> holder_map() const { return holder_map_; }
+  bool is_dictionary_holder() const { return holder_map_->is_dictionary_map(); }
   Handle<Map> transition_map() const {
     DCHECK_EQ(TRANSITION, state_);
     return transition_map_;
   }
   template <class T>
   Handle<T> GetHolder() const {
     DCHECK(IsFound());
     return Handle<T>::cast(maybe_holder_.ToHandleChecked());
   }
   Handle<JSReceiver> GetRoot() const;
@@ skipping 15 matching lines @@
       has_property_ = true;
     }
     return cacheable;
   }
   void ApplyTransitionToDataProperty();
   void ReconfigureDataProperty(Handle<Object> value,
                                PropertyAttributes attributes);
   void TransitionToAccessorProperty(AccessorComponent component,
                                     Handle<Object> accessor,
                                     PropertyAttributes attributes);
-  PropertyEncoding property_encoding() const {
-    DCHECK(has_property_);
-    return property_encoding_;
-  }
   PropertyDetails property_details() const {
     DCHECK(has_property_);
     return property_details_;
   }
   bool IsConfigurable() const { return property_details().IsConfigurable(); }
   bool IsReadOnly() const { return property_details().IsReadOnly(); }
   Representation representation() const {
     return property_details().representation();
   }
   FieldIndex GetFieldIndex() const;
@@ skipping 25 matching lines @@
   }
   bool check_hidden() const { return (configuration_ & kHidden) != 0; }
   bool check_interceptor() const {
     return !IsBootstrapping() && (configuration_ & kInterceptor) != 0;
   }
   bool check_prototype_chain() const {
     return (configuration_ & kPrototypeChain) != 0;
   }
   int descriptor_number() const {
     DCHECK(has_property_);
-    DCHECK_EQ(DESCRIPTOR, property_encoding_);
+    DCHECK(!holder_map_->is_dictionary_map());
     return number_;
   }
   int dictionary_entry() const {
     DCHECK(has_property_);
-    DCHECK_EQ(DICTIONARY, property_encoding_);
+    DCHECK(holder_map_->is_dictionary_map());
     return number_;
   }
 
   static Configuration ComputeConfiguration(
       Configuration configuration, Handle<Name> name) {
     if (name->IsOwn()) {
       return static_cast<Configuration>(configuration & HIDDEN);
     } else {
       return configuration;
     }
   }
 
   // If configuration_ becomes mutable, update
   // HolderIsReceiverOrHiddenPrototype.
   Configuration configuration_;
   State state_;
   bool has_property_;
-  PropertyEncoding property_encoding_;
   PropertyDetails property_details_;
   Isolate* isolate_;
   Handle<Name> name_;
   Handle<Map> holder_map_;
   Handle<Map> transition_map_;
   MaybeHandle<Object> maybe_receiver_;
   MaybeHandle<JSReceiver> maybe_holder_;
 
   int number_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOOKUP_H_