[heap] Simplify clearing of normalized map caches.

src/heap/heap.cc

 // 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.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/assembler-inl.h"
 #include "src/ast/context-slot-cache.h"
@@ skipping 1231 matching lines @@
 
 void Heap::EnsureFromSpaceIsCommitted() {
   if (new_space_->CommitFromSpaceIfNeeded()) return;
 
   // Committing memory to from space failed.
   // Memory is exhausted and we will die.
   V8::FatalProcessOutOfMemory("Committing semi space failed.");
 }
 
 
-void Heap::ClearNormalizedMapCaches() {
-  if (isolate_->bootstrapper()->IsActive() &&

[ulan, 2017/03/13 14:36:01]

I don't understand the intent of this condition. We don't clear the caches if
the bootstrapper is active and we're doing full GC.

This is going to change to clearing unconditionally.

-      !incremental_marking()->IsMarking()) {
-    return;
-  }
-
-  Object* context = native_contexts_list();
-  while (!context->IsUndefined(isolate())) {
-    // GC can happen when the context is not fully initialized,
-    // so the cache can be undefined.
-    Object* cache =
-        Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX);
-    if (!cache->IsUndefined(isolate())) {
-      NormalizedMapCache::cast(cache)->Clear();
-    }
-    context = Context::cast(context)->next_context_link();
-  }
-}
-
-
 void Heap::UpdateSurvivalStatistics(int start_new_space_size) {
   if (start_new_space_size == 0) return;
 
   promotion_ratio_ = (static_cast<double>(promoted_objects_size_) /
                       static_cast<double>(start_new_space_size) * 100);
 
   if (previous_semi_space_copied_object_size_ > 0) {
     promotion_rate_ =
         (static_cast<double>(promoted_objects_size_) /
          static_cast<double>(previous_semi_space_copied_object_size_) * 100);
@@ skipping 221 matching lines @@
   isolate_->context_slot_cache()->Clear();
   isolate_->descriptor_lookup_cache()->Clear();
   RegExpResultsCache::Clear(string_split_cache());
   RegExpResultsCache::Clear(regexp_multiple_cache());
 
   isolate_->compilation_cache()->MarkCompactPrologue();
 
   CompletelyClearInstanceofCache();
 
   FlushNumberStringCache();
-  ClearNormalizedMapCaches();
 }
 
 
 void Heap::CheckNewSpaceExpansionCriteria() {
   if (FLAG_experimental_new_space_growth_heuristic) {
     if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() &&
         survived_last_scavenge_ * 100 / new_space_->TotalCapacity() >= 10) {
       // Grow the size of new space if there is room to grow, and more than 10%
       // have survived the last scavenge.
       new_space_->Grow();
@@ skipping 4850 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8