Avoid one repeated property lookup when computing load ICs.

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 81 matching lines @@
   Handle<Object> GetReceiver() const {
     return Handle<Object>::cast(maybe_receiver_.ToHandleChecked());
   }
   Handle<Map> holder_map() const { return holder_map_; }
   template <class T>
   Handle<T> GetHolder() const {
     ASSERT(IsFound());
     return Handle<T>::cast(maybe_holder_.ToHandleChecked());
   }
   Handle<JSReceiver> GetRoot() const;
-  bool HolderIsReceiver() const;
+  bool HolderIsReceiverOrHiddenPrototype() const;
 
   /* Dynamically reduce the trapped types. */
   void skip_interceptor() {
     configuration_ = static_cast<Configuration>(
         configuration_ & ~CHECK_INTERCEPTOR);
   }
   void skip_access_check() {
     configuration_ = static_cast<Configuration>(
         configuration_ & ~CHECK_ACCESS_CHECK);
   }
 
   /* ACCESS_CHECK */
   bool HasAccess(v8::AccessType access_type) const;
 
   /* PROPERTY */
   // HasProperty needs to be called before any of the other PROPERTY methods
   // below can be used. It ensures that we are able to provide a definite
   // answer, and loads extra information about the property.
   bool HasProperty();
   void PrepareForDataProperty(Handle<Object> value);
   void TransitionToDataProperty(Handle<Object> value,
                                 PropertyAttributes attributes,
                                 Object::StoreFromKeyed store_mode);
   PropertyKind property_kind() const {
     ASSERT(has_property_);
     return property_kind_;
   }
+  PropertyEncoding property_encoding() const {
+    ASSERT(has_property_);
+    return property_encoding_;
+  }
   PropertyDetails property_details() const {
     ASSERT(has_property_);
     return property_details_;
   }
-  int descriptor_number() const {
-    ASSERT(has_property_);
-    ASSERT_EQ(DESCRIPTOR, property_encoding_);
-    return number_;
+  bool IsConfigurable() const { return !property_details().IsDontDelete(); }
+  Representation representation() const {
+    return property_details().representation();
   }
+  FieldIndex GetFieldIndex() const;
+  Handle<PropertyCell> GetPropertyCell() const;
   Handle<Object> GetAccessors() const;
   Handle<Object> GetDataValue() const;
   void WriteDataValue(Handle<Object> value);
 
   void InternalizeName();
 
  private:
   Handle<Map> GetReceiverMap() const;
 
   MUST_USE_RESULT bool NextHolder();
@@ skipping 14 matching lines @@
   }
   bool check_derived() const {
     return (configuration_ & CHECK_DERIVED) != 0;
   }
   bool check_hidden() const {
     return (configuration_ & CHECK_HIDDEN) != 0;
   }
   bool check_access_check() const {
     return (configuration_ & CHECK_ACCESS_CHECK) != 0;
   }
+  int descriptor_number() const {
+    ASSERT(has_property_);
+    ASSERT_EQ(DESCRIPTOR, property_encoding_);
+    return number_;
+  }
+  int dictionary_entry() const {
+    ASSERT(has_property_);
+    ASSERT_EQ(DICTIONARY, property_encoding_);
+    return number_;
+  }
 
   Configuration configuration_;
   State state_;
   bool has_property_;
   PropertyKind property_kind_;
   PropertyEncoding property_encoding_;
   PropertyDetails property_details_;
   Isolate* isolate_;
   Handle<Name> name_;
   Handle<Map> holder_map_;
   MaybeHandle<Object> maybe_receiver_;
   MaybeHandle<JSReceiver> maybe_holder_;
 
   int number_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOOKUP_H_