Introduce a lookup cache class in the runtime system and use it for...

src/objects.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 40 matching lines @@
 //         _ JSGlobalProxy
 //         - JSValue
 //         - Script
 //       - Array
 //         - ByteArray
 //         - FixedArray
 //           - DescriptorArray
 //           - HashTable
 //             - Dictionary
 //             - SymbolTable
+//             - CompilationCacheTable
+//             - MapCache
+//             - LookupCache
 //           - Context
 //           - GlobalContext
 //       - String
 //         - SeqString
 //           - SeqAsciiString
 //           - SeqTwoByteString
 //         - ConsString
 //         - SlicedString
 //         - ExternalString
 //           - ExternalAsciiString
@@ skipping 548 matching lines @@
   inline bool IsJSValue();
   inline bool IsProxy();
   inline bool IsBoolean();
   inline bool IsJSArray();
   inline bool IsJSRegExp();
   inline bool IsHashTable();
   inline bool IsDictionary();
   inline bool IsSymbolTable();
   inline bool IsCompilationCacheTable();
   inline bool IsMapCache();
+  inline bool IsLookupCache();
   inline bool IsPrimitive();
   inline bool IsGlobalObject();
   inline bool IsJSGlobalObject();
   inline bool IsJSBuiltinsObject();
   inline bool IsJSGlobalProxy();
   inline bool IsUndetectableObject();
   inline bool IsAccessCheckNeeded();
 
   // Returns true if this object is an instance of the specified
   // function template.
@@ skipping 1224 matching lines @@
   // Find cached value for a string key, otherwise return null.
   Object* Lookup(FixedArray* key);
   Object* Put(FixedArray* key, Map* value);
   static inline MapCache* cast(Object* obj);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(MapCache);
 };
 
 
+// LookupCache.
+//
+// Maps a key consisting of a map and a name to an index within a
+// fast-case properties array.
+//
+// LookupCaches are used to avoid repeatedly searching instance
+// descriptors.
+class LookupCache: public HashTable<0, 2> {
+ public:
+  int Lookup(Map* map, String* name);
+  Object* Put(Map* map, String* name, int offset);
+  static inline LookupCache* cast(Object* obj);
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(LookupCache);
+};
+
+
 // Dictionary for keeping properties and elements in slow case.
 //
 // One element in the prefix is used for storing non-element
 // information about the dictionary.
 //
 // The rest of the array embeds triples of (key, value, details).
 // if key == undefined the triple is empty.
 // if key == null the triple has been deleted.
 // otherwise key contains the name of a property.
 class DictionaryBase: public HashTable<2, 3> {};
@@ skipping 2168 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_