v8:3539 - hold constructor feedback in weak cells

src/type-feedback-vector.cc

 // Copyright 2014 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/v8.h"
 
 #include "src/ic/ic.h"
 #include "src/ic/ic-state.h"
 #include "src/objects.h"
 #include "src/type-feedback-vector-inl.h"
@@ skipping 121 matching lines @@
     Isolate* isolate, Handle<TypeFeedbackVector> vector) {
   Handle<TypeFeedbackVector> result;
   result = Handle<TypeFeedbackVector>::cast(
       isolate->factory()->CopyFixedArray(Handle<FixedArray>::cast(vector)));
   return result;
 }
 
 
 // This logic is copied from
 // StaticMarkingVisitor<StaticVisitor>::VisitCodeTarget.
-static bool ClearLogic(Heap* heap, int ic_age) {
+static bool ClearLogic(Heap* heap) {
   return FLAG_cleanup_code_caches_at_gc &&
          heap->isolate()->serializer_enabled();
 }
 
 
-void TypeFeedbackVector::ClearSlots(SharedFunctionInfo* shared) {
+void TypeFeedbackVector::ClearSlotsImpl(SharedFunctionInfo* shared,
+                                        bool force_clear) {
   int slots = Slots();
-  Isolate* isolate = GetIsolate();
+  Heap* heap = GetIsolate()->heap();
+
+  if (!force_clear && !ClearLogic(heap)) return;
+
   Object* uninitialized_sentinel =
-      TypeFeedbackVector::RawUninitializedSentinel(isolate->heap());
-
+      TypeFeedbackVector::RawUninitializedSentinel(heap);
   for (int i = 0; i < slots; i++) {
     FeedbackVectorSlot slot(i);
     Object* obj = Get(slot);
     if (obj->IsHeapObject()) {
       InstanceType instance_type =
           HeapObject::cast(obj)->map()->instance_type();
       // AllocationSites are exempt from clearing. They don't store Maps
       // or Code pointers which can cause memory leaks if not cleared
       // regularly.
       if (instance_type != ALLOCATION_SITE_TYPE) {
         Set(slot, uninitialized_sentinel, SKIP_WRITE_BARRIER);
       }
     }
   }
 }
 
 
 void TypeFeedbackVector::ClearICSlotsImpl(SharedFunctionInfo* shared,
                                           bool force_clear) {
   Heap* heap = GetIsolate()->heap();
 
-  // I'm not sure yet if this ic age is the correct one.
-  int ic_age = shared->ic_age();
-
-  if (!force_clear && !ClearLogic(heap, ic_age)) return;
+  if (!force_clear && !ClearLogic(heap)) return;
 
   int slots = ICSlots();
   Code* host = shared->code();
   Object* uninitialized_sentinel =
       TypeFeedbackVector::RawUninitializedSentinel(heap);
   for (int i = 0; i < slots; i++) {
     FeedbackVectorICSlot slot(i);
     Object* obj = Get(slot);
     if (obj != uninitialized_sentinel) {
       Code::Kind kind = GetKind(slot);
@@ skipping 347 matching lines @@
 
 Name* KeyedLoadICNexus::FindFirstName() const {
   Object* feedback = GetFeedback();
   if (feedback->IsString()) {
     return Name::cast(feedback);
   }
   return NULL;
 }
 }
 }  // namespace v8::internal