[heap] Provide ObjectMarking with marking transitions

BUG=chromium:651354

Review-Url: https://codereview.chromium.org/2644523002
Cr-Commit-Position: refs/heads/master@{#42531}

src/heap/array-buffer-tracker.cc

@@ -19,8 +19,7 @@ void LocalArrayBufferTracker::Free() {
   for (TrackingData::iterator it = array_buffers_.begin();
        it != array_buffers_.end();) {
     JSArrayBuffer* buffer = reinterpret_cast<JSArrayBuffer*>(it->first);
-    if ((free_mode == kFreeAll) ||
-        Marking::IsWhite(ObjectMarking::MarkBitFrom(buffer))) {
+    if ((free_mode == kFreeAll) || ObjectMarking::IsWhite(buffer)) {
       const size_t len = it->second;
       heap_->isolate()->array_buffer_allocator()->Free(buffer->backing_store(),
                                                        len);

src/heap/heap.cc

@@ -3183,7 +3183,7 @@ void Heap::AdjustLiveBytes(HeapObject* object, int by) {
     lo_space()->AdjustLiveBytes(by);
   } else if (!in_heap_iterator() &&
              !mark_compact_collector()->sweeping_in_progress() &&
-             Marking::IsBlack(ObjectMarking::MarkBitFrom(object))) {
+             ObjectMarking::IsBlack(object)) {
     DCHECK(MemoryChunk::FromAddress(object->address())->SweepingDone());
     MemoryChunk::IncrementLiveBytes(object, by);
   }
@@ -3193,6 +3193,7 @@ void Heap::AdjustLiveBytes(HeapObject* object, int by) {
 FixedArrayBase* Heap::LeftTrimFixedArray(FixedArrayBase* object,
                                          int elements_to_trim) {
   CHECK_NOT_NULL(object);
+  DCHECK(CanMoveObjectStart(object));
   DCHECK(!object->IsFixedTypedArrayBase());
   DCHECK(!object->IsByteArray());
   const int element_size = object->IsFixedArray() ? kPointerSize : kDoubleSize;
@@ -3243,7 +3244,6 @@ FixedArrayBase* Heap::LeftTrimFixedArray(FixedArrayBase* object,
   // Initialize header of the trimmed array. Since left trimming is only
   // performed on pages which are not concurrently swept creating a filler
   // object does not require synchronization.
-  DCHECK(CanMoveObjectStart(object));
   Object** former_start = HeapObject::RawField(object, 0);
   int new_start_index = elements_to_trim * (element_size / kPointerSize);
   former_start[new_start_index] = map;
@@ -3314,7 +3314,7 @@ void Heap::RightTrimFixedArray(FixedArrayBase* object, int elements_to_trim) {
     // Clear the mark bits of the black area that belongs now to the filler.
     // This is an optimization. The sweeper will release black fillers anyway.
     if (incremental_marking()->black_allocation() &&
-        Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(filler))) {
+        ObjectMarking::IsBlackOrGrey(filler)) {
       Page* page = Page::FromAddress(new_end);
       page->markbits()->ClearRange(
           page->AddressToMarkbitIndex(new_end),
@@ -4309,17 +4309,19 @@ void Heap::RegisterReservationsForBlackAllocation(Reservation* reservations) {
   // Hence we have to color all objects of the reservation first black to avoid
   // unnecessary marking deque load.
   if (incremental_marking()->black_allocation()) {
-    for (int i = OLD_SPACE; i < Serializer::kNumberOfSpaces; i++) {
+    for (int i = CODE_SPACE; i < Serializer::kNumberOfSpaces; i++) {
       const Heap::Reservation& res = reservations[i];
       for (auto& chunk : res) {
         Address addr = chunk.start;
         while (addr < chunk.end) {
           HeapObject* obj = HeapObject::FromAddress(addr);
-          Marking::MarkBlack(ObjectMarking::MarkBitFrom(obj));
+          ObjectMarking::WhiteToBlack(obj);
           addr += obj->Size();
         }
       }
     }
+    // Iterate black objects in old space, code space, map space, and large
+    // object space for side effects.
     for (int i = OLD_SPACE; i < Serializer::kNumberOfSpaces; i++) {
       const Heap::Reservation& res = reservations[i];
       for (auto& chunk : res) {
@@ -4898,8 +4900,7 @@ void Heap::IterateAndScavengePromotedObject(HeapObject* target, int size,
   // it would be a violation of the invariant to record it's slots.
   bool record_slots = false;
   if (incremental_marking()->IsCompacting()) {
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(target);
-    record_slots = Marking::IsBlack(mark_bit);
+    record_slots = ObjectMarking::IsBlack(target);
   }
 
   IterateAndScavengePromotedObjectsVisitor visitor(this, target, record_slots);
@@ -6137,8 +6138,7 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
 
   bool SkipObject(HeapObject* object) {
     if (object->IsFiller()) return true;
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(object);
-    return Marking::IsWhite(mark_bit);
+    return ObjectMarking::IsWhite(object);
   }
 
  private:
@@ -6150,6 +6150,8 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
       for (Object** p = start; p < end; p++) {
         if (!(*p)->IsHeapObject()) continue;
         HeapObject* obj = HeapObject::cast(*p);
+        // Use Marking instead of ObjectMarking to avoid adjusting live bytes
+        // counter.
         MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
         if (Marking::IsWhite(mark_bit)) {
           Marking::WhiteToBlack(mark_bit);

src/heap/incremental-marking.cc

@@ -39,15 +39,12 @@ IncrementalMarking::IncrementalMarking(Heap* heap)
 
 bool IncrementalMarking::BaseRecordWrite(HeapObject* obj, Object* value) {
   HeapObject* value_heap_obj = HeapObject::cast(value);
-  MarkBit value_bit = ObjectMarking::MarkBitFrom(value_heap_obj);
-  DCHECK(!Marking::IsImpossible(value_bit));
+  DCHECK(!ObjectMarking::IsImpossible(value_heap_obj));
+  DCHECK(!ObjectMarking::IsImpossible(obj));
+  const bool is_black = ObjectMarking::IsBlack(obj);
 
-  MarkBit obj_bit = ObjectMarking::MarkBitFrom(obj);
-  DCHECK(!Marking::IsImpossible(obj_bit));
-  bool is_black = Marking::IsBlack(obj_bit);
-
-  if (is_black && Marking::IsWhite(value_bit)) {
-    WhiteToGreyAndPush(value_heap_obj, value_bit);
+  if (is_black && ObjectMarking::IsWhite(value_heap_obj)) {
+    WhiteToGreyAndPush(value_heap_obj);
     RestartIfNotMarking();
   }
   return is_compacting_ && is_black;
@@ -118,9 +115,8 @@ void IncrementalMarking::RecordWriteIntoCodeSlow(Code* host, RelocInfo* rinfo,
   }
 }
 
-
-void IncrementalMarking::WhiteToGreyAndPush(HeapObject* obj, MarkBit mark_bit) {
-  Marking::WhiteToGrey(mark_bit);
+void IncrementalMarking::WhiteToGreyAndPush(HeapObject* obj) {
+  ObjectMarking::WhiteToGrey(obj);
   heap_->mark_compact_collector()->marking_deque()->Push(obj);
 }
 
@@ -128,16 +124,13 @@ void IncrementalMarking::WhiteToGreyAndPush(HeapObject* obj, MarkBit mark_bit) {
 static void MarkObjectGreyDoNotEnqueue(Object* obj) {
   if (obj->IsHeapObject()) {
     HeapObject* heap_obj = HeapObject::cast(obj);
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(HeapObject::cast(obj));
-    if (Marking::IsBlack(mark_bit)) {
-      MemoryChunk::IncrementLiveBytes(heap_obj, -heap_obj->Size());
-    }
-    Marking::AnyToGrey(mark_bit);
+    ObjectMarking::AnyToGrey(heap_obj);
   }
 }
 
 void IncrementalMarking::TransferMark(Heap* heap, HeapObject* from,
                                       HeapObject* to) {
+  DCHECK(MemoryChunk::FromAddress(from->address())->SweepingDone());
   // This is only used when resizing an object.
   DCHECK(MemoryChunk::FromAddress(from->address()) ==
          MemoryChunk::FromAddress(to->address()));
@@ -158,11 +151,12 @@ void IncrementalMarking::TransferMark(Heap* heap, HeapObject* from,
 
   if (Marking::IsBlack(old_mark_bit)) {
     Marking::BlackToWhite(old_mark_bit);
-    Marking::MarkBlack(new_mark_bit);
+    Marking::WhiteToBlack(new_mark_bit);
     return;
   } else if (Marking::IsGrey(old_mark_bit)) {
     Marking::GreyToWhite(old_mark_bit);
-    heap->incremental_marking()->WhiteToGreyAndPush(to, new_mark_bit);
+    Marking::WhiteToGrey(new_mark_bit);
+    heap->mark_compact_collector()->marking_deque()->Push(to);
     heap->incremental_marking()->RestartIfNotMarking();
   }
 
@@ -210,10 +204,10 @@ class IncrementalMarkingMarkingVisitor
       } while (scan_until_end && start_offset < object_size);
       chunk->set_progress_bar(start_offset);
       if (start_offset < object_size) {
-        if (Marking::IsGrey(ObjectMarking::MarkBitFrom(object))) {
+        if (ObjectMarking::IsGrey(object)) {
           heap->mark_compact_collector()->marking_deque()->Unshift(object);
         } else {
-          DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
+          DCHECK(ObjectMarking::IsBlack(object));
           heap->mark_compact_collector()->UnshiftBlack(object);
         }
         heap->incremental_marking()->NotifyIncompleteScanOfObject(
@@ -265,10 +259,8 @@ class IncrementalMarkingMarkingVisitor
   // Returns true if object needed marking and false otherwise.
   INLINE(static bool MarkObjectWithoutPush(Heap* heap, Object* obj)) {
     HeapObject* heap_object = HeapObject::cast(obj);
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(heap_object);
-    if (Marking::IsWhite(mark_bit)) {
-      Marking::MarkBlack(mark_bit);
-      MemoryChunk::IncrementLiveBytes(heap_object, heap_object->Size());
+    if (ObjectMarking::IsWhite(heap_object)) {
+      ObjectMarking::WhiteToBlack(heap_object);
       return true;
     }
     return false;
@@ -276,7 +268,7 @@ class IncrementalMarkingMarkingVisitor
 };
 
 void IncrementalMarking::IterateBlackObject(HeapObject* object) {
-  if (IsMarking() && Marking::IsBlack(ObjectMarking::MarkBitFrom(object))) {
+  if (IsMarking() && ObjectMarking::IsBlack(object)) {
     Page* page = Page::FromAddress(object->address());
     if ((page->owner() != nullptr) && (page->owner()->identity() == LO_SPACE)) {
       // IterateBlackObject requires us to visit the whole object.
@@ -661,8 +653,7 @@ bool ShouldRetainMap(Map* map, int age) {
   }
   Object* constructor = map->GetConstructor();
   if (!constructor->IsHeapObject() ||
-      Marking::IsWhite(
-          ObjectMarking::MarkBitFrom(HeapObject::cast(constructor)))) {
+      ObjectMarking::IsWhite(HeapObject::cast(constructor))) {
     // The constructor is dead, no new objects with this map can
     // be created. Do not retain this map.
     return false;
@@ -691,16 +682,14 @@ void IncrementalMarking::RetainMaps() {
     int age = Smi::cast(retained_maps->Get(i + 1))->value();
     int new_age;
     Map* map = Map::cast(cell->value());
-    MarkBit map_mark = ObjectMarking::MarkBitFrom(map);
     if (i >= number_of_disposed_maps && !map_retaining_is_disabled &&
-        Marking::IsWhite(map_mark)) {
+        ObjectMarking::IsWhite(map)) {
       if (ShouldRetainMap(map, age)) {
         MarkGrey(heap(), map);
       }
       Object* prototype = map->prototype();
       if (age > 0 && prototype->IsHeapObject() &&
-          Marking::IsWhite(
-              ObjectMarking::MarkBitFrom(HeapObject::cast(prototype)))) {
+          ObjectMarking::IsWhite(HeapObject::cast(prototype))) {
         // The prototype is not marked, age the map.
         new_age = age - 1;
       } else {
@@ -807,15 +796,12 @@ void IncrementalMarking::UpdateMarkingDequeAfterScavenge() {
       // them.
       if (map_word.IsForwardingAddress()) {
         HeapObject* dest = map_word.ToForwardingAddress();
-        if (Marking::IsBlack(ObjectMarking::MarkBitFrom(dest))) continue;
+        if (ObjectMarking::IsBlack(dest)) continue;
         array[new_top] = dest;
         new_top = ((new_top + 1) & mask);
         DCHECK(new_top != marking_deque->bottom());
-#ifdef DEBUG
-        MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-        DCHECK(Marking::IsGrey(mark_bit) ||
-               (obj->IsFiller() && Marking::IsWhite(mark_bit)));
-#endif
+        DCHECK(ObjectMarking::IsGrey(obj) ||
+               (obj->IsFiller() && ObjectMarking::IsWhite(obj)));
       }
     } else if (obj->map() != filler_map) {
       // Skip one word filler objects that appear on the
@@ -823,14 +809,11 @@ void IncrementalMarking::UpdateMarkingDequeAfterScavenge() {
       array[new_top] = obj;
       new_top = ((new_top + 1) & mask);
       DCHECK(new_top != marking_deque->bottom());
-#ifdef DEBUG
-      MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-      MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
-      DCHECK(Marking::IsGrey(mark_bit) ||
-             (obj->IsFiller() && Marking::IsWhite(mark_bit)) ||
-             (chunk->IsFlagSet(MemoryChunk::HAS_PROGRESS_BAR) &&
-              Marking::IsBlack(mark_bit)));
-#endif
+      DCHECK(ObjectMarking::IsGrey(obj) ||
+             (obj->IsFiller() && ObjectMarking::IsWhite(obj)) ||
+             (MemoryChunk::FromAddress(obj->address())
+                  ->IsFlagSet(MemoryChunk::HAS_PROGRESS_BAR) &&
+              ObjectMarking::IsBlack(obj)));
     }
   }
   marking_deque->set_top(new_top);
@@ -854,17 +837,14 @@ void IncrementalMarking::VisitObject(Map* map, HeapObject* obj, int size) {
 }
 
 void IncrementalMarking::MarkGrey(Heap* heap, HeapObject* object) {
-  MarkBit mark_bit = ObjectMarking::MarkBitFrom(object);
-  if (Marking::IsWhite(mark_bit)) {
-    heap->incremental_marking()->WhiteToGreyAndPush(object, mark_bit);
+  if (ObjectMarking::IsWhite(object)) {
+    heap->incremental_marking()->WhiteToGreyAndPush(object);
   }
 }
 
 void IncrementalMarking::MarkBlack(HeapObject* obj, int size) {
-  MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-  if (Marking::IsBlack(mark_bit)) return;
-  Marking::GreyToBlack(mark_bit);
-  MemoryChunk::IncrementLiveBytes(obj, size);
+  if (ObjectMarking::IsBlack(obj)) return;
+  ObjectMarking::GreyToBlack(obj);
 }
 
 intptr_t IncrementalMarking::ProcessMarkingDeque(
@@ -879,8 +859,7 @@ intptr_t IncrementalMarking::ProcessMarkingDeque(
     // Left trimming may result in white filler objects on the marking deque.
     // Ignore these objects.
     if (obj->IsFiller()) {
-      DCHECK(Marking::IsImpossible(ObjectMarking::MarkBitFrom(obj)) ||
-             Marking::IsWhite(ObjectMarking::MarkBitFrom(obj)));
+      DCHECK(ObjectMarking::IsImpossible(obj) || ObjectMarking::IsWhite(obj));
       continue;
     }
 
@@ -935,10 +914,8 @@ void IncrementalMarking::Hurry() {
     HeapObject* cache = HeapObject::cast(
         Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX));
     if (!cache->IsUndefined(heap_->isolate())) {
-      MarkBit mark_bit = ObjectMarking::MarkBitFrom(cache);
-      if (Marking::IsGrey(mark_bit)) {
-        Marking::GreyToBlack(mark_bit);
-        MemoryChunk::IncrementLiveBytes(cache, cache->Size());
+      if (ObjectMarking::IsGrey(cache)) {
+        ObjectMarking::GreyToBlack(cache);
       }
     }
     context = Context::cast(context)->next_context_link();

src/heap/incremental-marking.h

@@ -158,7 +158,7 @@ class IncrementalMarking {
   void RecordCodeTargetPatch(Code* host, Address pc, HeapObject* value);
   void RecordCodeTargetPatch(Address pc, HeapObject* value);
 
-  void WhiteToGreyAndPush(HeapObject* obj, MarkBit mark_bit);
+  void WhiteToGreyAndPush(HeapObject* obj);
 
   inline void SetOldSpacePageFlags(MemoryChunk* chunk) {
     SetOldSpacePageFlags(chunk, IsMarking(), IsCompacting());

src/heap/mark-compact-inl.h

@@ -13,48 +13,38 @@ namespace v8 {
 namespace internal {
 
 void MarkCompactCollector::PushBlack(HeapObject* obj) {
-  DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(obj)));
-  if (marking_deque()->Push(obj)) {
-    MemoryChunk::IncrementLiveBytes(obj, obj->Size());
-  } else {
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-    Marking::BlackToGrey(mark_bit);
+  DCHECK(ObjectMarking::IsBlack(obj));
+  if (!marking_deque()->Push(obj)) {
+    ObjectMarking::BlackToGrey(obj);
   }
 }
 
 
 void MarkCompactCollector::UnshiftBlack(HeapObject* obj) {
-  DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(obj)));
+  DCHECK(ObjectMarking::IsBlack(obj));
   if (!marking_deque()->Unshift(obj)) {
-    MemoryChunk::IncrementLiveBytes(obj, -obj->Size());
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-    Marking::BlackToGrey(mark_bit);
+    ObjectMarking::BlackToGrey(obj);
   }
 }
 
 
 void MarkCompactCollector::MarkObject(HeapObject* obj, MarkBit mark_bit) {
   DCHECK(ObjectMarking::MarkBitFrom(obj) == mark_bit);
-  if (Marking::IsWhite(mark_bit)) {
-    Marking::WhiteToBlack(mark_bit);
-    DCHECK(obj->GetIsolate()->heap()->Contains(obj));
+  if (ObjectMarking::IsWhite(obj)) {
+    ObjectMarking::WhiteToBlack(obj);
     PushBlack(obj);
   }
 }
 
-
-void MarkCompactCollector::SetMark(HeapObject* obj, MarkBit mark_bit) {
-  DCHECK(Marking::IsWhite(mark_bit));
-  DCHECK(ObjectMarking::MarkBitFrom(obj) == mark_bit);
-  Marking::WhiteToBlack(mark_bit);
-  MemoryChunk::IncrementLiveBytes(obj, obj->Size());
+void MarkCompactCollector::SetMark(HeapObject* obj) {
+  DCHECK(ObjectMarking::IsWhite(obj));
+  ObjectMarking::WhiteToBlack(obj);
 }
 
 
 bool MarkCompactCollector::IsMarked(Object* obj) {
   DCHECK(obj->IsHeapObject());
-  HeapObject* heap_object = HeapObject::cast(obj);
-  return Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(heap_object));
+  return ObjectMarking::IsBlackOrGrey(HeapObject::cast(obj));
 }
 
 
@@ -64,7 +54,7 @@ void MarkCompactCollector::RecordSlot(HeapObject* object, Object** slot,
   Page* source_page = Page::FromAddress(reinterpret_cast<Address>(object));
   if (target_page->IsEvacuationCandidate() &&
       !ShouldSkipEvacuationSlotRecording(object)) {
-    DCHECK(Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(object)));
+    DCHECK(IsMarked(object));
     RememberedSet<OLD_TO_OLD>::Insert(source_page,
                                       reinterpret_cast<Address>(slot));
   }

src/heap/mark-compact.cc

@@ -107,7 +107,7 @@ static void VerifyMarking(Heap* heap, Address bottom, Address top) {
     // One word fillers at the end of a black area can be grey.
     if (MarkCompactCollector::IsMarked(object) &&
         object->map() != heap->one_pointer_filler_map()) {
-      CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
+      CHECK(ObjectMarking::IsBlack(object));
       CHECK(current >= next_object_must_be_here_or_later);
       object->Iterate(&visitor);
       next_object_must_be_here_or_later = current + object->Size();
@@ -348,8 +348,7 @@ void MarkCompactCollector::VerifyMarkbitsAreClean() {
 
   LargeObjectIterator it(heap_->lo_space());
   for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-    CHECK(Marking::IsWhite(mark_bit));
+    CHECK(ObjectMarking::IsWhite(obj));
     CHECK_EQ(0, Page::FromAddress(obj->address())->LiveBytes());
   }
 }
@@ -398,7 +397,7 @@ void MarkCompactCollector::ClearMarkbits() {
 
   LargeObjectIterator it(heap_->lo_space());
   for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
-    Marking::MarkWhite(ObjectMarking::MarkBitFrom(obj));
+    ObjectMarking::ClearMarkBit(obj);
     MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
     chunk->ResetProgressBar();
     chunk->ResetLiveBytes();
@@ -909,8 +908,7 @@ void CodeFlusher::ProcessJSFunctionCandidates() {
     SharedFunctionInfo* shared = candidate->shared();
 
     Code* code = shared->code();
-    MarkBit code_mark = ObjectMarking::MarkBitFrom(code);
-    if (Marking::IsWhite(code_mark)) {
+    if (ObjectMarking::IsWhite(code)) {
       if (FLAG_trace_code_flushing && shared->is_compiled()) {
         PrintF("[code-flushing clears: ");
         shared->ShortPrint();
@@ -928,7 +926,7 @@ void CodeFlusher::ProcessJSFunctionCandidates() {
         candidate->set_code(lazy_compile);
       }
     } else {
-      DCHECK(Marking::IsBlack(code_mark));
+      DCHECK(ObjectMarking::IsBlack(code));
       candidate->set_code(code);
     }
 
@@ -962,8 +960,7 @@ void CodeFlusher::ProcessSharedFunctionInfoCandidates() {
     ClearNextCandidate(candidate);
 
     Code* code = candidate->code();
-    MarkBit code_mark = ObjectMarking::MarkBitFrom(code);
-    if (Marking::IsWhite(code_mark)) {
+    if (ObjectMarking::IsWhite(code)) {
       if (FLAG_trace_code_flushing && candidate->is_compiled()) {
         PrintF("[code-flushing clears: ");
         candidate->ShortPrint();
@@ -1103,9 +1100,8 @@ class StaticYoungGenerationMarkingVisitor
     StackLimitCheck check(heap->isolate());
     if (check.HasOverflowed()) return false;
 
-    MarkBit mark = ObjectMarking::MarkBitFrom(object);
-    if (Marking::IsBlackOrGrey(mark)) return true;
-    heap->mark_compact_collector()->SetMark(object, mark);
+    if (ObjectMarking::IsBlackOrGrey(object)) return true;
+    heap->mark_compact_collector()->SetMark(object);
     IterateBody(object->map(), object);
     return true;
   }
@@ -1143,9 +1139,8 @@ class MarkCompactMarkingVisitor
   // Marks the object black without pushing it on the marking stack.
   // Returns true if object needed marking and false otherwise.
   INLINE(static bool MarkObjectWithoutPush(Heap* heap, HeapObject* object)) {
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(object);
-    if (Marking::IsWhite(mark_bit)) {
-      heap->mark_compact_collector()->SetMark(object, mark_bit);
+    if (ObjectMarking::IsWhite(object)) {
+      heap->mark_compact_collector()->SetMark(object);
       return true;
     }
     return false;
@@ -1171,8 +1166,7 @@ class MarkCompactMarkingVisitor
 #endif
     Map* map = obj->map();
     Heap* heap = obj->GetHeap();
-    MarkBit mark = ObjectMarking::MarkBitFrom(obj);
-    heap->mark_compact_collector()->SetMark(obj, mark);
+    heap->mark_compact_collector()->SetMark(obj);
     // Mark the map pointer and the body.
     MarkBit map_mark = ObjectMarking::MarkBitFrom(map);
     heap->mark_compact_collector()->MarkObject(map, map_mark);
@@ -1194,8 +1188,7 @@ class MarkCompactMarkingVisitor
       if (!o->IsHeapObject()) continue;
       collector->RecordSlot(object, p, o);
       HeapObject* obj = HeapObject::cast(o);
-      MarkBit mark = ObjectMarking::MarkBitFrom(obj);
-      if (Marking::IsBlackOrGrey(mark)) continue;
+      if (ObjectMarking::IsBlackOrGrey(obj)) continue;
       VisitUnmarkedObject(collector, obj);
     }
     return true;
@@ -1228,7 +1221,7 @@ class MarkCompactMarkingVisitor
       // was marked through the compilation cache before marker reached JSRegExp
       // object.
       FixedArray* data = FixedArray::cast(re->data());
-      if (Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(data))) {
+      if (ObjectMarking::IsBlackOrGrey(data)) {
         Object** slot =
             data->data_start() + JSRegExp::saved_code_index(is_one_byte);
         heap->mark_compact_collector()->RecordSlot(data, slot, code);
@@ -1394,12 +1387,11 @@ class RootMarkingVisitor : public ObjectVisitor {
         !collector_->heap()->InNewSpace(object))
       return;
 
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(object);
-    if (Marking::IsBlackOrGrey(mark_bit)) return;
+    if (ObjectMarking::IsBlackOrGrey(object)) return;
 
     Map* map = object->map();
     // Mark the object.
-    collector_->SetMark(object, mark_bit);
+    collector_->SetMark(object);
 
     switch (mode) {
       case MarkCompactMode::FULL: {
@@ -1437,7 +1429,7 @@ class StringTableCleaner : public ObjectVisitor {
     for (Object** p = start; p < end; p++) {
       Object* o = *p;
       if (o->IsHeapObject()) {
-        if (Marking::IsWhite(ObjectMarking::MarkBitFrom(HeapObject::cast(o)))) {
+        if (ObjectMarking::IsWhite(HeapObject::cast(o))) {
           if (finalize_external_strings) {
             if (o->IsExternalString()) {
               heap_->FinalizeExternalString(String::cast(*p));
@@ -1478,9 +1470,8 @@ typedef StringTableCleaner<true, false> ExternalStringTableCleaner;
 class MarkCompactWeakObjectRetainer : public WeakObjectRetainer {
  public:
   virtual Object* RetainAs(Object* object) {
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(HeapObject::cast(object));
-    DCHECK(!Marking::IsGrey(mark_bit));
-    if (Marking::IsBlack(mark_bit)) {
+    DCHECK(!ObjectMarking::IsGrey(HeapObject::cast(object)));
+    if (ObjectMarking::IsBlack(HeapObject::cast(object))) {
       return object;
     } else if (object->IsAllocationSite() &&
                !(AllocationSite::cast(object)->IsZombie())) {
@@ -1508,9 +1499,8 @@ void MarkCompactCollector::DiscoverGreyObjectsWithIterator(T* it) {
 
   Map* filler_map = heap()->one_pointer_filler_map();
   for (HeapObject* object = it->Next(); object != NULL; object = it->Next()) {
-    MarkBit markbit = ObjectMarking::MarkBitFrom(object);
-    if ((object->map() != filler_map) && Marking::IsGrey(markbit)) {
-      Marking::GreyToBlack(markbit);
+    if ((object->map() != filler_map) && ObjectMarking::IsGrey(object)) {
+      ObjectMarking::GreyToBlack(object);
       PushBlack(object);
       if (marking_deque()->IsFull()) return;
     }
@@ -1522,9 +1512,8 @@ void MarkCompactCollector::DiscoverGreyObjectsOnPage(MemoryChunk* p) {
   LiveObjectIterator<kGreyObjects> it(p);
   HeapObject* object = NULL;
   while ((object = it.Next()) != NULL) {
-    MarkBit markbit = ObjectMarking::MarkBitFrom(object);
-    DCHECK(Marking::IsGrey(markbit));
-    Marking::GreyToBlack(markbit);
+    DCHECK(ObjectMarking::IsGrey(object));
+    ObjectMarking::GreyToBlack(object);
     PushBlack(object);
     if (marking_deque()->IsFull()) return;
   }
@@ -1974,9 +1963,7 @@ void MarkCompactCollector::DiscoverGreyObjectsInNewSpace() {
 bool MarkCompactCollector::IsUnmarkedHeapObject(Object** p) {
   Object* o = *p;
   if (!o->IsHeapObject()) return false;
-  HeapObject* heap_object = HeapObject::cast(o);
-  MarkBit mark = ObjectMarking::MarkBitFrom(heap_object);
-  return Marking::IsWhite(mark);
+  return ObjectMarking::IsWhite(HeapObject::cast(o));
 }
 
 
@@ -1984,19 +1971,16 @@ bool MarkCompactCollector::IsUnmarkedHeapObjectWithHeap(Heap* heap,
                                                         Object** p) {
   Object* o = *p;
   DCHECK(o->IsHeapObject());
-  HeapObject* heap_object = HeapObject::cast(o);
-  MarkBit mark = ObjectMarking::MarkBitFrom(heap_object);
-  return Marking::IsWhite(mark);
+  return ObjectMarking::IsWhite(HeapObject::cast(o));
 }
 
 void MarkCompactCollector::MarkStringTable(
     RootMarkingVisitor<MarkCompactMode::FULL>* visitor) {
   StringTable* string_table = heap()->string_table();
   // Mark the string table itself.
-  MarkBit string_table_mark = ObjectMarking::MarkBitFrom(string_table);
-  if (Marking::IsWhite(string_table_mark)) {
+  if (ObjectMarking::IsWhite(string_table)) {
     // String table could have already been marked by visiting the handles list.
-    SetMark(string_table, string_table_mark);
+    SetMark(string_table);
   }
   // Explicitly mark the prefix.
   string_table->IteratePrefix(visitor);
@@ -2005,8 +1989,7 @@ void MarkCompactCollector::MarkStringTable(
 
 
 void MarkCompactCollector::MarkAllocationSite(AllocationSite* site) {
-  MarkBit mark_bit = ObjectMarking::MarkBitFrom(site);
-  SetMark(site, mark_bit);
+  SetMark(site);
 }
 
 void MarkCompactCollector::MarkRoots(
@@ -2069,7 +2052,7 @@ void MarkCompactCollector::EmptyMarkingDeque() {
     DCHECK(!object->IsFiller());
     DCHECK(object->IsHeapObject());
     DCHECK(heap()->Contains(object));
-    DCHECK(!Marking::IsWhite(ObjectMarking::MarkBitFrom(object)));
+    DCHECK(!ObjectMarking::IsWhite(object));
 
     Map* map = object->map();
     switch (mode) {
@@ -2079,7 +2062,7 @@ void MarkCompactCollector::EmptyMarkingDeque() {
         MarkCompactMarkingVisitor::IterateBody(map, object);
       } break;
       case MarkCompactMode::YOUNG_GENERATION: {
-        DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
+        DCHECK(ObjectMarking::IsBlack(object));
         StaticYoungGenerationMarkingVisitor::IterateBody(map, object);
       } break;
     }
@@ -2280,10 +2263,10 @@ class MarkCompactCollector::ObjectStatsVisitor
   }
 
   bool Visit(HeapObject* obj) override {
-    if (Marking::IsBlack(ObjectMarking::MarkBitFrom(obj))) {
+    if (ObjectMarking::IsBlack(obj)) {
       live_collector_.CollectStatistics(obj);
     } else {
-      DCHECK(!Marking::IsGrey(ObjectMarking::MarkBitFrom(obj)));
+      DCHECK(!ObjectMarking::IsGrey(obj));
       dead_collector_.CollectStatistics(obj);
     }
     return true;
@@ -2339,11 +2322,10 @@ SlotCallbackResult MarkCompactCollector::CheckAndMarkObject(
     // has to be in ToSpace.
     DCHECK(heap->InToSpace(object));
     HeapObject* heap_object = reinterpret_cast<HeapObject*>(object);
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(heap_object);
-    if (Marking::IsBlackOrGrey(mark_bit)) {
+    if (ObjectMarking::IsBlackOrGrey(heap_object)) {
       return KEEP_SLOT;
     }
-    heap->mark_compact_collector()->SetMark(heap_object, mark_bit);
+    heap->mark_compact_collector()->SetMark(heap_object);
     StaticYoungGenerationMarkingVisitor::IterateBody(heap_object->map(),
                                                      heap_object);
     return KEEP_SLOT;
@@ -2353,8 +2335,7 @@ SlotCallbackResult MarkCompactCollector::CheckAndMarkObject(
 
 static bool IsUnmarkedObject(Heap* heap, Object** p) {
   DCHECK_IMPLIES(heap->InNewSpace(*p), heap->InToSpace(*p));
-  return heap->InNewSpace(*p) &&
-         !Marking::IsBlack(ObjectMarking::MarkBitFrom(HeapObject::cast(*p)));
+  return heap->InNewSpace(*p) && !ObjectMarking::IsBlack(HeapObject::cast(*p));
 }
 
 void MarkCompactCollector::MarkLiveObjectsInYoungGeneration() {
@@ -2636,11 +2617,11 @@ void MarkCompactCollector::ClearSimpleMapTransitions(
   while (weak_cell_obj != Smi::kZero) {
     WeakCell* weak_cell = WeakCell::cast(weak_cell_obj);
     Map* map = Map::cast(weak_cell->value());
-    DCHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(map)));
+    DCHECK(ObjectMarking::IsWhite(map));
     Object* potential_parent = map->constructor_or_backpointer();
     if (potential_parent->IsMap()) {
       Map* parent = Map::cast(potential_parent);
-      if (Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(parent)) &&
+      if (ObjectMarking::IsBlackOrGrey(parent) &&
           parent->raw_transitions() == weak_cell) {
         ClearSimpleMapTransition(parent, map);
       }
@@ -2679,8 +2660,7 @@ void MarkCompactCollector::ClearFullMapTransitions() {
     if (num_transitions > 0) {
       Map* map = array->GetTarget(0);
       Map* parent = Map::cast(map->constructor_or_backpointer());
-      bool parent_is_alive =
-          Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(parent));
+      bool parent_is_alive = ObjectMarking::IsBlackOrGrey(parent);
       DescriptorArray* descriptors =
           parent_is_alive ? parent->instance_descriptors() : nullptr;
       bool descriptors_owner_died =
@@ -2705,7 +2685,7 @@ bool MarkCompactCollector::CompactTransitionArray(
   for (int i = 0; i < num_transitions; ++i) {
     Map* target = transitions->GetTarget(i);
     DCHECK_EQ(target->constructor_or_backpointer(), map);
-    if (Marking::IsWhite(ObjectMarking::MarkBitFrom(target))) {
+    if (ObjectMarking::IsWhite(target)) {
       if (descriptors != nullptr &&
           target->instance_descriptors() == descriptors) {
         descriptors_owner_died = true;
@@ -2880,8 +2860,7 @@ void MarkCompactCollector::ClearWeakCells(Object** non_live_map_list,
         if (cell_value->IsHeapObject() &&
             MarkCompactCollector::IsMarked(HeapObject::cast(cell_value))) {
           // Resurrect the cell.
-          MarkBit mark = ObjectMarking::MarkBitFrom(value);
-          SetMark(value, mark);
+          SetMark(value);
           Object** slot = HeapObject::RawField(value, Cell::kValueOffset);
           RecordSlot(value, slot, *slot);
           slot = HeapObject::RawField(weak_cell, WeakCell::kValueOffset);
@@ -3423,7 +3402,7 @@ int MarkCompactCollector::Sweeper::RawSweep(
   HeapObject* object = NULL;
 
   while ((object = it.Next()) != NULL) {
-    DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
+    DCHECK(ObjectMarking::IsBlack(object));
     Address free_end = object->address();
     if (free_end != free_start) {
       CHECK_GT(free_end, free_start);
@@ -3513,8 +3492,7 @@ void MarkCompactCollector::InvalidateCode(Code* code) {
     DCHECK(compacting_);
 
     // If the object is white than no slots were recorded on it yet.
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(code);
-    if (Marking::IsWhite(mark_bit)) return;
+    if (ObjectMarking::IsWhite(code)) return;
 
     // Ignore all slots that might have been recorded in the body of the
     // deoptimized code object. Assumption: no slots will be recorded for
@@ -3535,7 +3513,7 @@ static void VerifyAllBlackObjects(MemoryChunk* page) {
   LiveObjectIterator<kAllLiveObjects> it(page);
   HeapObject* object = NULL;
   while ((object = it.Next()) != NULL) {
-    CHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
+    CHECK(ObjectMarking::IsBlack(object));
   }
 }
 #endif  // VERIFY_HEAP
@@ -3550,7 +3528,7 @@ bool MarkCompactCollector::VisitLiveObjects(MemoryChunk* page, Visitor* visitor,
   LiveObjectIterator<kBlackObjects> it(page);
   HeapObject* object = nullptr;
   while ((object = it.Next()) != nullptr) {
-    DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
+    DCHECK(ObjectMarking::IsBlack(object));
     if (!visitor->Visit(object)) {
       if (mode == kClearMarkbits) {
         page->markbits()->ClearRange(
@@ -3747,8 +3725,7 @@ class PointerUpdateJobTraits {
       // slot has been recorded multiple times in the remembered set. Since
       // there is no forwarding information present we need to check the
       // markbits to determine liveness.
-      if (Marking::IsBlack(ObjectMarking::MarkBitFrom(
-              reinterpret_cast<HeapObject*>(slot_reference))))
+      if (ObjectMarking::IsBlack(reinterpret_cast<HeapObject*>(slot_reference)))
         return KEEP_SLOT;
     } else {
       DCHECK(!heap->InNewSpace(slot_reference));
@@ -4082,8 +4059,7 @@ void MarkCompactCollector::RecordCodeTargetPatch(Address pc, Code* target) {
     Code* host =
         isolate()->inner_pointer_to_code_cache()->GcSafeFindCodeForInnerPointer(
             pc);
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(host);
-    if (Marking::IsBlack(mark_bit)) {
+    if (ObjectMarking::IsBlack(host)) {
       RelocInfo rinfo(isolate(), pc, RelocInfo::CODE_TARGET, 0, host);
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.

src/heap/mark-compact.h

@@ -46,6 +46,76 @@ class ObjectMarking : public AllStatic {
     return Marking::Color(ObjectMarking::MarkBitFrom(obj));
   }
 
+  V8_INLINE static bool IsImpossible(HeapObject* obj) {
+    return Marking::IsImpossible(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static bool IsBlack(HeapObject* obj) {
+    return Marking::IsBlack(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static bool IsWhite(HeapObject* obj) {
+    return Marking::IsWhite(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static bool IsGrey(HeapObject* obj) {
+    return Marking::IsGrey(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static bool IsBlackOrGrey(HeapObject* obj) {
+    return Marking::IsBlackOrGrey(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static void ClearMarkBit(HeapObject* obj) {
+    Marking::MarkWhite(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static void BlackToWhite(HeapObject* obj) {
+    DCHECK(IsBlack(obj));
+    MarkBit markbit = MarkBitFrom(obj);
+    Marking::BlackToWhite(markbit);
+    MemoryChunk::IncrementLiveBytes(obj, -obj->Size());
+  }
+
+  V8_INLINE static void GreyToWhite(HeapObject* obj) {
+    DCHECK(IsGrey(obj));
+    Marking::GreyToWhite(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static void BlackToGrey(HeapObject* obj) {
+    DCHECK(IsBlack(obj));
+    MarkBit markbit = MarkBitFrom(obj);
+    Marking::BlackToGrey(markbit);
+    MemoryChunk::IncrementLiveBytes(obj, -obj->Size());
+  }
+
+  V8_INLINE static void WhiteToGrey(HeapObject* obj) {
+    DCHECK(IsWhite(obj));
+    Marking::WhiteToGrey(MarkBitFrom(obj));
+  }
+
+  V8_INLINE static void WhiteToBlack(HeapObject* obj) {
+    DCHECK(IsWhite(obj));
+    MarkBit markbit = MarkBitFrom(obj);
+    Marking::WhiteToBlack(markbit);
+    MemoryChunk::IncrementLiveBytes(obj, obj->Size());
+  }
+
+  V8_INLINE static void GreyToBlack(HeapObject* obj) {
+    DCHECK(IsGrey(obj));
+    MarkBit markbit = MarkBitFrom(obj);
+    Marking::GreyToBlack(markbit);
+    MemoryChunk::IncrementLiveBytes(obj, obj->Size());
+  }
+
+  V8_INLINE static void AnyToGrey(HeapObject* obj) {
+    MarkBit markbit = MarkBitFrom(obj);
+    if (Marking::IsBlack(markbit)) {
+      MemoryChunk::IncrementLiveBytes(obj, -obj->Size());
+    }
+    Marking::AnyToGrey(markbit);
+  }
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectMarking);
 };
@@ -595,7 +665,7 @@ class MarkCompactCollector {
 
   // Marks the object black assuming that it is not yet marked.
   // This is for non-incremental marking only.
-  INLINE(void SetMark(HeapObject* obj, MarkBit mark_bit));
+  INLINE(void SetMark(HeapObject* obj));
 
   // Mark the heap roots and all objects reachable from them.
   void MarkRoots(RootMarkingVisitor<MarkCompactMode::FULL>* visitor);

src/heap/objects-visiting-inl.h

@@ -534,8 +534,7 @@ bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(Heap* heap,
 
   // Code is either on stack, in compilation cache or referenced
   // by optimized version of function.
-  MarkBit code_mark = ObjectMarking::MarkBitFrom(function->code());
-  if (Marking::IsBlackOrGrey(code_mark)) {
+  if (ObjectMarking::IsBlackOrGrey(function->code())) {
     return false;
   }
 
@@ -558,8 +557,7 @@ bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(
     Heap* heap, SharedFunctionInfo* shared_info) {
   // Code is either on stack, in compilation cache or referenced
   // by optimized version of function.
-  MarkBit code_mark = ObjectMarking::MarkBitFrom(shared_info->code());
-  if (Marking::IsBlackOrGrey(code_mark)) {
+  if (ObjectMarking::IsBlackOrGrey(shared_info->code())) {
     return false;
   }
 

src/heap/scavenger.cc

@@ -200,9 +200,8 @@ class ScavengingVisitor : public StaticVisitorBase {
                                    reinterpret_cast<base::AtomicWord>(target));
 
       if (object_contents == POINTER_OBJECT) {
-        heap->promotion_queue()->insert(
-            target, object_size,
-            Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
+        heap->promotion_queue()->insert(target, object_size,
+                                        ObjectMarking::IsBlack(object));
       }
       heap->IncrementPromotedObjectsSize(object_size);
       return true;
@@ -246,8 +245,7 @@ class ScavengingVisitor : public StaticVisitorBase {
     DCHECK(map_word.IsForwardingAddress());
     HeapObject* target = map_word.ToForwardingAddress();
 
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(target);
-    if (Marking::IsBlack(mark_bit)) {
+    if (ObjectMarking::IsBlack(target)) {
       // This object is black and it might not be rescanned by marker.
       // We should explicitly record code entry slot for compaction because
       // promotion queue processing (IteratePromotedObjectPointers) will

src/heap/spaces.cc

@@ -1459,7 +1459,7 @@ void PagedSpace::Verify(ObjectVisitor* visitor) {
       // All the interior pointers should be contained in the heap.
       int size = object->Size();
       object->IterateBody(map->instance_type(), size, visitor);
-      if (Marking::IsBlack(ObjectMarking::MarkBitFrom(object))) {
+      if (ObjectMarking::IsBlack(object)) {
         black_size += size;
       }
 
@@ -2990,7 +2990,8 @@ AllocationResult LargeObjectSpace::AllocateRaw(int object_size,
   AllocationStep(object->address(), object_size);
 
   if (heap()->incremental_marking()->black_allocation()) {
-    Marking::MarkBlack(ObjectMarking::MarkBitFrom(object));
+    // We cannot use ObjectMarking here as the object still lacks a size.
+    Marking::WhiteToBlack(ObjectMarking::MarkBitFrom(object));
     MemoryChunk::IncrementLiveBytes(object, object_size);
   }
   return object;
@@ -3039,9 +3040,8 @@ void LargeObjectSpace::ClearMarkingStateOfLiveObjects() {
   LargePage* current = first_page_;
   while (current != NULL) {
     HeapObject* object = current->GetObject();
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(object);
-    DCHECK(Marking::IsBlack(mark_bit));
-    Marking::BlackToWhite(mark_bit);
+    DCHECK(ObjectMarking::IsBlack(object));
+    ObjectMarking::BlackToWhite(object);
     Page::FromAddress(object->address())->ResetProgressBar();
     Page::FromAddress(object->address())->ResetLiveBytes();
     current = current->next_page();
@@ -3086,9 +3086,8 @@ void LargeObjectSpace::FreeUnmarkedObjects() {
   LargePage* current = first_page_;
   while (current != NULL) {
     HeapObject* object = current->GetObject();
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(object);
-    DCHECK(!Marking::IsGrey(mark_bit));
-    if (Marking::IsBlack(mark_bit)) {
+    DCHECK(!ObjectMarking::IsGrey(object));
+    if (ObjectMarking::IsBlack(object)) {
       Address free_start;
       if ((free_start = current->GetAddressToShrink()) != 0) {
         // TODO(hpayer): Perform partial free concurrently.
@@ -3223,7 +3222,7 @@ void Page::Print() {
   unsigned mark_size = 0;
   for (HeapObject* object = objects.Next(); object != NULL;
        object = objects.Next()) {
-    bool is_marked = Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(object));
+    bool is_marked = ObjectMarking::IsBlackOrGrey(object);
     PrintF(" %c ", (is_marked ? '!' : ' '));  // Indent a little.
     if (is_marked) {
       mark_size += object->Size();

src/objects-inl.h

@@ -2121,7 +2121,7 @@ void WeakCell::initialize(HeapObject* val) {
   // We just have to execute the generational barrier here because we never
   // mark through a weak cell and collect evacuation candidates when we process
   // all weak cells.
-  WriteBarrierMode mode = Marking::IsBlack(ObjectMarking::MarkBitFrom(this))
+  WriteBarrierMode mode = ObjectMarking::IsBlack(this)
                               ? UPDATE_WRITE_BARRIER
                               : UPDATE_WEAK_WRITE_BARRIER;
   CONDITIONAL_WRITE_BARRIER(GetHeap(), this, kValueOffset, val, mode);