Reapplying r5147 (caching maps for slow case objects)....

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 553 matching lines @@
 };
 
 
 void Heap::ClearJSFunctionResultCaches() {
   if (Bootstrapper::IsActive()) return;
   ClearThreadJSFunctionResultCachesVisitor visitor;
   ThreadManager::IterateArchivedThreads(&visitor);
 }
 
 
+class ClearThreadNormalizedMapCachesVisitor: public ThreadVisitor {
+  virtual void VisitThread(ThreadLocalTop* top) {
+    Context* context = top->context_;
+    if (context == NULL) return;
+    context->global()->global_context()->normalized_map_cache()->Clear();
+  }
+};
+
+
+void Heap::ClearNormalizedMapCaches() {
+  if (Bootstrapper::IsActive()) return;
+  ClearThreadNormalizedMapCachesVisitor visitor;
+  ThreadManager::IterateArchivedThreads(&visitor);
+}
+
+
 #ifdef DEBUG
 
 enum PageWatermarkValidity {
   ALL_VALID,
   ALL_INVALID
 };
 
 static void VerifyPageWatermarkValidity(PagedSpace* space,
                                         PageWatermarkValidity validity) {
   PageIterator it(space, PageIterator::PAGES_IN_USE);
@@ skipping 164 matching lines @@
   DescriptorLookupCache::Clear();
 
   CompilationCache::MarkCompactPrologue();
 
   Top::MarkCompactPrologue(is_compacting);
   ThreadManager::MarkCompactPrologue(is_compacting);
 
   CompletelyClearInstanceofCache();
 
   if (is_compacting) FlushNumberStringCache();
+
+  ClearNormalizedMapCaches();
 }
 
 
 void Heap::MarkCompactEpilogue(bool is_compacting) {
   Top::MarkCompactEpilogue(is_compacting);
   ThreadManager::MarkCompactEpilogue(is_compacting);
 }
 
 
 Object* Heap::FindCodeObject(Address a) {
@@ skipping 4091 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal