Added descriptor lookup cache to eliminate some search overhead....

src/heap.cc

 // Copyright 2009 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 484 matching lines @@
   Counters::objs_since_last_full.Set(0);
   context_disposed_pending_ = false;
 }
 
 
 void Heap::MarkCompactPrologue(bool is_compacting) {
   // At any old GC clear the keyed lookup cache to enable collection of unused
   // maps.
   KeyedLookupCache::Clear();
   ContextSlotCache::Clear();
+  DescriptorLookupCache::Clear();
 
   CompilationCache::MarkCompactPrologue();
 
   Top::MarkCompactPrologue(is_compacting);
   ThreadManager::MarkCompactPrologue(is_compacting);
 }
 
 
 void Heap::MarkCompactEpilogue(bool is_compacting) {
   Top::MarkCompactEpilogue(is_compacting);
@@ skipping 108 matching lines @@
 void Heap::Scavenge() {
 #ifdef DEBUG
   if (FLAG_enable_slow_asserts) VerifyNonPointerSpacePointers();
 #endif
 
   gc_state_ = SCAVENGE;
 
   // Implements Cheney's copying algorithm
   LOG(ResourceEvent("scavenge", "begin"));
 
+  // Clear descriptor cache.
+  DescriptorLookupCache::Clear();
+
   // Used for updating survived_since_last_expansion_ at function end.
   int survived_watermark = PromotedSpaceSize();
 
   if (new_space_.Capacity() < new_space_.MaximumCapacity() &&
       survived_since_last_expansion_ > new_space_.Capacity()) {
     // Double the size of new space if there is room to grow and enough
     // data has survived scavenge since the last expansion.
     // TODO(1240712): NewSpace::Double has a return value which is
     // ignored here.
     new_space_.Double();
@@ skipping 742 matching lines @@
 
   // Handling of script id generation is in Factory::NewScript.
   last_script_id_ = undefined_value();
 
   // Initialize keyed lookup cache.
   KeyedLookupCache::Clear();
 
   // Initialize context slot cache.
   ContextSlotCache::Clear();
 
+  // Initialize descriptor cache.
+  DescriptorLookupCache::Clear();
+
   // Initialize compilation cache.
   CompilationCache::Clear();
 
   return true;
 }
 
 
 static inline int double_get_hash(double d) {
   DoubleRepresentation rep(d);
   return ((static_cast<int>(rep.bits) ^ static_cast<int>(rep.bits >> 32)) &
@@ skipping 2147 matching lines @@
   for (int index = 0; index < kLength; index++) keys_[index].map = NULL;
 }
 
 
 KeyedLookupCache::Key KeyedLookupCache::keys_[KeyedLookupCache::kLength];
 
 
 int KeyedLookupCache::field_offsets_[KeyedLookupCache::kLength];
 
 
+void DescriptorLookupCache::Clear() {
+  for (int index = 0; index < kLength; index++) keys_[index].array = NULL;
+}
+
+
+DescriptorLookupCache::Key
+DescriptorLookupCache::keys_[DescriptorLookupCache::kLength];
+
+int DescriptorLookupCache::results_[DescriptorLookupCache::kLength];
+
+
 #ifdef DEBUG
 bool Heap::GarbageCollectionGreedyCheck() {
   ASSERT(FLAG_gc_greedy);
   if (Bootstrapper::IsActive()) return true;
   if (disallow_allocation_failure()) return true;
   return CollectGarbage(0, NEW_SPACE);
 }
 #endif
 
 } }  // namespace v8::internal