Implement aging of maps embedded in optimized code.

src/heap/heap.h

 // Copyright 2012 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_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 
 #include "src/allocation.h"
@@ skipping 814 matching lines @@
   void set_allocation_sites_list(Object* object) {
     allocation_sites_list_ = object;
   }
   Object* allocation_sites_list() { return allocation_sites_list_; }
 
   // Used in CreateAllocationSiteStub and the (de)serializer.
   Object** allocation_sites_list_address() { return &allocation_sites_list_; }
 
   Object* weak_object_to_code_table() { return weak_object_to_code_table_; }
 
+  Object* embedded_map_cache() { return embedded_map_cache_; }
+
   void set_encountered_weak_collections(Object* weak_collection) {
     encountered_weak_collections_ = weak_collection;
   }
   Object* encountered_weak_collections() const {
     return encountered_weak_collections_;
   }
 
   void set_encountered_weak_cells(Object* weak_cell) {
     encountered_weak_cells_ = weak_cell;
   }
   Object* encountered_weak_cells() const { return encountered_weak_cells_; }
 
   // Number of mark-sweeps.
   unsigned int ms_count() { return ms_count_; }
 
   // Iterates over all roots in the heap.
   void IterateRoots(ObjectVisitor* v, VisitMode mode);
   // Iterates over all strong roots in the heap.
   void IterateStrongRoots(ObjectVisitor* v, VisitMode mode);
   // Iterates over entries in the smi roots list.  Only interesting to the
   // serializer/deserializer, since GC does not care about smis.
   void IterateSmiRoots(ObjectVisitor* v);
   // Iterates over all the other roots in the heap.
   void IterateWeakRoots(ObjectVisitor* v, VisitMode mode);
 
   // Iterate pointers to from semispace of new space found in memory interval
   // from start to end.
   void IterateAndMarkPointersToFromSpace(Address start, Address end,
                                          ObjectSlotCallback callback);
+  void IterateEmbeddedMapCache(ObjectVisitor* v);
 
   // Returns whether the object resides in new space.
   inline bool InNewSpace(Object* object);
   inline bool InNewSpace(Address address);
   inline bool InNewSpacePage(Address address);
   inline bool InFromSpace(Object* object);
   inline bool InToSpace(Object* object);
 
   // Returns whether the object resides in old pointer space.
   inline bool InOldPointerSpace(Address address);
@@ skipping 517 matching lines @@
 
   void AddWeakObjectToCodeDependency(Handle<Object> obj,
                                      Handle<DependentCode> dep);
 
   DependentCode* LookupWeakObjectToCodeDependency(Handle<Object> obj);
 
   void InitializeWeakObjectToCodeTable() {
     set_weak_object_to_code_table(undefined_value());
   }
 
+  void InitializeEmbeddedMapCache() { embedded_map_cache_ = undefined_value(); }
+
   void EnsureWeakObjectToCodeTable();
 
+  void CacheEmbeddedMap(Handle<Map> map);
+
   static void FatalProcessOutOfMemory(const char* location,
                                       bool take_snapshot = false);
 
   // This event is triggered after successful allocation of a new object made
   // by runtime. Allocations of target space for object evacuation do not
   // trigger the event. In order to track ALL allocations one must turn off
   // FLAG_inline_new and FLAG_use_allocation_folding.
   inline void OnAllocationEvent(HeapObject* object, int size_in_bytes);
 
   // This event is triggered after object is moved to a new place.
@@ skipping 163 matching lines @@
   // List heads are initilized lazily and contain the undefined_value at start.
   Object* native_contexts_list_;
   Object* array_buffers_list_;
   Object* allocation_sites_list_;
 
   // WeakHashTable that maps objects embedded in optimized code to dependent
   // code list. It is initilized lazily and contains the undefined_value at
   // start.
   Object* weak_object_to_code_table_;
 
+  Object* embedded_map_cache_;
+
   // List of encountered weak collections (JSWeakMap and JSWeakSet) during
   // marking. It is initialized during marking, destroyed after marking and
   // contains Smi(0) while marking is not active.
   Object* encountered_weak_collections_;
 
   Object* encountered_weak_cells_;
 
   StoreBufferRebuilder store_buffer_rebuilder_;
 
   struct StringTypeTable {
@@ skipping 398 matching lines @@
 
   void set_weak_object_to_code_table(Object* value) {
     DCHECK(!InNewSpace(value));
     weak_object_to_code_table_ = value;
   }
 
   Object** weak_object_to_code_table_address() {
     return &weak_object_to_code_table_;
   }
 
+  Object** embedded_map_cache_address() { return &embedded_map_cache_; }
+
   inline void UpdateAllocationsHash(HeapObject* object);
   inline void UpdateAllocationsHash(uint32_t value);
   inline void PrintAlloctionsHash();
 
   static const int kInitialStringTableSize = 2048;
   static const int kInitialEvalCacheSize = 64;
   static const int kInitialNumberStringCacheSize = 256;
 
   // Object counts and used memory by InstanceType
   size_t object_counts_[OBJECT_STATS_COUNT];
@@ skipping 541 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_H_