Add a single-element global positive and negative cache to...

src/heap.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 75 matching lines @@
   V(Map, external_float_array_map, ExternalFloatArrayMap)                      \
   V(Map, context_map, ContextMap)                                              \
   V(Map, catch_context_map, CatchContextMap)                                   \
   V(Map, code_map, CodeMap)                                                    \
   V(Map, oddball_map, OddballMap)                                              \
   V(Map, global_property_cell_map, GlobalPropertyCellMap)                      \
   V(Map, shared_function_info_map, SharedFunctionInfoMap)                      \
   V(Map, proxy_map, ProxyMap)                                                  \
   V(Object, nan_value, NanValue)                                               \
   V(Object, minus_zero_value, MinusZeroValue)                                  \
+  V(Object, instanceof_cache_function, InstanceofCacheFunction)                \
+  V(Object, instanceof_cache_map, InstanceofCacheMap)                          \
+  V(Object, instanceof_cache_answer, InstanceofCacheAnswer)                    \
   V(String, empty_string, EmptyString)                                         \
   V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray)             \
   V(Map, neander_map, NeanderMap)                                              \
   V(JSObject, message_listeners, MessageListeners)                             \
   V(Proxy, prototype_accessors, PrototypeAccessors)                            \
   V(NumberDictionary, code_stubs, CodeStubs)                                   \
   V(NumberDictionary, non_monomorphic_cache, NonMonomorphicCache)              \
   V(Code, js_entry_code, JsEntryCode)                                          \
   V(Code, js_construct_entry_code, JsConstructEntryCode)                       \
   V(Code, c_entry_code, CEntryCode)                                            \
@@ skipping 248 matching lines @@
   // Allocates a partial map for bootstrapping.
   static Object* AllocatePartialMap(InstanceType instance_type,
                                     int instance_size);
 
   // Allocate a map for the specified function
   static Object* AllocateInitialMap(JSFunction* fun);
 
   // Allocates an empty code cache.
   static Object* AllocateCodeCache();
 
+  // Clear the Instanceof cache (used when a prototype changes).
+  static void ClearInstanceofCache() {
+    set_instanceof_cache_function(the_hole_value());
+  }
+
   // Allocates and fully initializes a String.  There are two String
   // encodings: ASCII and two byte. One should choose between the three string
   // allocation functions based on the encoding of the string buffer used to
   // initialized the string.
   //   - ...FromAscii initializes the string from a buffer that is ASCII
   //     encoded (it does not check that the buffer is ASCII encoded) and the
   //     result will be ASCII encoded.
   //   - ...FromUTF8 initializes the string from a buffer that is UTF-8
   //     encoded.  If the characters are all single-byte characters, the
   //     result will be ASCII encoded, otherwise it will converted to two
@@ skipping 790 matching lines @@
   static Address DoScavenge(ObjectVisitor* scavenge_visitor,
                             Address new_space_front);
 
   // Performs a major collection in the whole heap.
   static void MarkCompact(GCTracer* tracer);
 
   // Code to be run before and after mark-compact.
   static void MarkCompactPrologue(bool is_compacting);
   static void MarkCompactEpilogue(bool is_compacting);
 
+  // Completely clear the Instanceof cache (to stop it keeping objects alive
+  // around a GC).
+  static void CompletelyClearInstanceofCache() {
+    set_instanceof_cache_map(the_hole_value());
+    set_instanceof_cache_function(the_hole_value());
+  }
+
   // Helper function used by CopyObject to copy a source object to an
   // allocated target object and update the forwarding pointer in the source
   // object.  Returns the target object.
   static inline HeapObject* MigrateObject(HeapObject* source,
                                           HeapObject* target,
                                           int size);
 
 #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING)
   // Record the copy of an object in the NewSpace's statistics.
   static void RecordCopiedObject(HeapObject* obj);
@@ skipping 634 matching lines @@
 
   // To speed up scavenge collections new space string are kept
   // separate from old space strings.
   static List<Object*> new_space_strings_;
   static List<Object*> old_space_strings_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_