Move ClearNonLiveReferences and friends into the gc.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/440063002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22864 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap/mark-compact.cc

@@ -2580,11 +2580,121 @@ void MarkCompactCollector::ClearNonLiveMapTransitions(Map* map,
   bool current_is_alive = map_mark.Get();
   bool parent_is_alive = Marking::MarkBitFrom(parent).Get();
   if (!current_is_alive && parent_is_alive) {
-    parent->ClearNonLiveTransitions(heap());
+    ClearMapTransitions(parent);
   }
 }
 
 
+// Clear a possible back pointer in case the transition leads to a dead map.
+// Return true in case a back pointer has been cleared and false otherwise.
+bool MarkCompactCollector::ClearMapBackPointer(Map* target) {
+  if (Marking::MarkBitFrom(target).Get()) return false;
+  target->SetBackPointer(heap_->undefined_value(), SKIP_WRITE_BARRIER);
+  return true;
+}
+
+
+void MarkCompactCollector::ClearMapTransitions(Map* map) {
+  // If there are no transitions to be cleared, return.
+  // TODO(verwaest) Should be an assert, otherwise back pointers are not
+  // properly cleared.
+  if (!map->HasTransitionArray()) return;
+
+  TransitionArray* t = map->transitions();
+
+  int transition_index = 0;
+
+  DescriptorArray* descriptors = map->instance_descriptors();
+  bool descriptors_owner_died = false;
+
+  // Compact all live descriptors to the left.
+  for (int i = 0; i < t->number_of_transitions(); ++i) {
+    Map* target = t->GetTarget(i);
+    if (ClearMapBackPointer(target)) {
+      if (target->instance_descriptors() == descriptors) {
+        descriptors_owner_died = true;
+      }
+    } else {
+      if (i != transition_index) {
+        Name* key = t->GetKey(i);
+        t->SetKey(transition_index, key);
+        Object** key_slot = t->GetKeySlot(transition_index);
+        RecordSlot(key_slot, key_slot, key);
+        // Target slots do not need to be recorded since maps are not compacted.
+        t->SetTarget(transition_index, t->GetTarget(i));
+      }
+      transition_index++;
+    }
+  }
+
+  // If there are no transitions to be cleared, return.
+  // TODO(verwaest) Should be an assert, otherwise back pointers are not
+  // properly cleared.
+  if (transition_index == t->number_of_transitions()) return;
+
+  int number_of_own_descriptors = map->NumberOfOwnDescriptors();
+
+  if (descriptors_owner_died) {
+    if (number_of_own_descriptors > 0) {
+      TrimDescriptorArray(map, descriptors, number_of_own_descriptors);
+      DCHECK(descriptors->number_of_descriptors() == number_of_own_descriptors);
+      map->set_owns_descriptors(true);
+    } else {
+      DCHECK(descriptors == heap_->empty_descriptor_array());
+    }
+  }
+
+  // Note that we never eliminate a transition array, though we might right-trim
+  // such that number_of_transitions() == 0. If this assumption changes,
+  // TransitionArray::CopyInsert() will need to deal with the case that a
+  // transition array disappeared during GC.
+  int trim = t->number_of_transitions() - transition_index;
+  if (trim > 0) {
+    heap_->RightTrimFixedArray<Heap::FROM_GC>(
+        t, t->IsSimpleTransition() ? trim
+                                   : trim * TransitionArray::kTransitionSize);
+  }
+  DCHECK(map->HasTransitionArray());
+}
+
+
+void MarkCompactCollector::TrimDescriptorArray(Map* map,
+                                               DescriptorArray* descriptors,
+                                               int number_of_own_descriptors) {
+  int number_of_descriptors = descriptors->number_of_descriptors_storage();
+  int to_trim = number_of_descriptors - number_of_own_descriptors;
+  if (to_trim == 0) return;
+
+  heap_->RightTrimFixedArray<Heap::FROM_GC>(
+      descriptors, to_trim * DescriptorArray::kDescriptorSize);
+  descriptors->SetNumberOfDescriptors(number_of_own_descriptors);
+
+  if (descriptors->HasEnumCache()) TrimEnumCache(map, descriptors);
+  descriptors->Sort();
+}
+
+
+void MarkCompactCollector::TrimEnumCache(Map* map,
+                                         DescriptorArray* descriptors) {
+  int live_enum = map->EnumLength();
+  if (live_enum == kInvalidEnumCacheSentinel) {
+    live_enum = map->NumberOfDescribedProperties(OWN_DESCRIPTORS, DONT_ENUM);
+  }
+  if (live_enum == 0) return descriptors->ClearEnumCache();
+
+  FixedArray* enum_cache = descriptors->GetEnumCache();
+
+  int to_trim = enum_cache->length() - live_enum;
+  if (to_trim <= 0) return;
+  heap_->RightTrimFixedArray<Heap::FROM_GC>(descriptors->GetEnumCache(),
+                                            to_trim);
+
+  if (!descriptors->HasEnumIndicesCache()) return;
+  FixedArray* enum_indices_cache = descriptors->GetEnumIndicesCache();
+  heap_->RightTrimFixedArray<Heap::FROM_GC>(enum_indices_cache, to_trim);
+}
+
+
 void MarkCompactCollector::ClearDependentICList(Object* head) {
   Object* current = head;
   Object* undefined = heap()->undefined_value();

src/heap/mark-compact.h

@@ -811,6 +811,11 @@ class MarkCompactCollector {
   void ClearNonLiveReferences();
   void ClearNonLivePrototypeTransitions(Map* map);
   void ClearNonLiveMapTransitions(Map* map, MarkBit map_mark);
+  void ClearMapTransitions(Map* map);
+  bool ClearMapBackPointer(Map* map);
+  void TrimDescriptorArray(Map* map, DescriptorArray* descriptors,
+                           int number_of_own_descriptors);
+  void TrimEnumCache(Map* map, DescriptorArray* descriptors);
 
   void ClearDependentCode(DependentCode* dependent_code);
   void ClearDependentICList(Object* head);

src/objects.cc

@@ -9533,119 +9533,6 @@ void String::PrintOn(FILE* file) {
 }
 
 
-static void TrimEnumCache(Heap* heap, Map* map, DescriptorArray* descriptors) {
-  int live_enum = map->EnumLength();
-  if (live_enum == kInvalidEnumCacheSentinel) {
-    live_enum = map->NumberOfDescribedProperties(OWN_DESCRIPTORS, DONT_ENUM);
-  }
-  if (live_enum == 0) return descriptors->ClearEnumCache();
-
-  FixedArray* enum_cache = descriptors->GetEnumCache();
-
-  int to_trim = enum_cache->length() - live_enum;
-  if (to_trim <= 0) return;
-  heap->RightTrimFixedArray<Heap::FROM_GC>(
-      descriptors->GetEnumCache(), to_trim);
-
-  if (!descriptors->HasEnumIndicesCache()) return;
-  FixedArray* enum_indices_cache = descriptors->GetEnumIndicesCache();
-  heap->RightTrimFixedArray<Heap::FROM_GC>(enum_indices_cache, to_trim);
-}
-
-
-static void TrimDescriptorArray(Heap* heap,
-                                Map* map,
-                                DescriptorArray* descriptors,
-                                int number_of_own_descriptors) {
-  int number_of_descriptors = descriptors->number_of_descriptors_storage();
-  int to_trim = number_of_descriptors - number_of_own_descriptors;
-  if (to_trim == 0) return;
-
-  heap->RightTrimFixedArray<Heap::FROM_GC>(
-      descriptors, to_trim * DescriptorArray::kDescriptorSize);
-  descriptors->SetNumberOfDescriptors(number_of_own_descriptors);
-
-  if (descriptors->HasEnumCache()) TrimEnumCache(heap, map, descriptors);
-  descriptors->Sort();
-}
-
-
-// Clear a possible back pointer in case the transition leads to a dead map.
-// Return true in case a back pointer has been cleared and false otherwise.
-static bool ClearBackPointer(Heap* heap, Map* target) {
-  if (Marking::MarkBitFrom(target).Get()) return false;
-  target->SetBackPointer(heap->undefined_value(), SKIP_WRITE_BARRIER);
-  return true;
-}
-
-
-// TODO(mstarzinger): This method should be moved into MarkCompactCollector,
-// because it cannot be called from outside the GC and we already have methods
-// depending on the transitions layout in the GC anyways.
-void Map::ClearNonLiveTransitions(Heap* heap) {
-  // If there are no transitions to be cleared, return.
-  // TODO(verwaest) Should be an assert, otherwise back pointers are not
-  // properly cleared.
-  if (!HasTransitionArray()) return;
-
-  TransitionArray* t = transitions();
-  MarkCompactCollector* collector = heap->mark_compact_collector();
-
-  int transition_index = 0;
-
-  DescriptorArray* descriptors = instance_descriptors();
-  bool descriptors_owner_died = false;
-
-  // Compact all live descriptors to the left.
-  for (int i = 0; i < t->number_of_transitions(); ++i) {
-    Map* target = t->GetTarget(i);
-    if (ClearBackPointer(heap, target)) {
-      if (target->instance_descriptors() == descriptors) {
-        descriptors_owner_died = true;
-      }
-    } else {
-      if (i != transition_index) {
-        Name* key = t->GetKey(i);
-        t->SetKey(transition_index, key);
-        Object** key_slot = t->GetKeySlot(transition_index);
-        collector->RecordSlot(key_slot, key_slot, key);
-        // Target slots do not need to be recorded since maps are not compacted.
-        t->SetTarget(transition_index, t->GetTarget(i));
-      }
-      transition_index++;
-    }
-  }
-
-  // If there are no transitions to be cleared, return.
-  // TODO(verwaest) Should be an assert, otherwise back pointers are not
-  // properly cleared.
-  if (transition_index == t->number_of_transitions()) return;
-
-  int number_of_own_descriptors = NumberOfOwnDescriptors();
-
-  if (descriptors_owner_died) {
-    if (number_of_own_descriptors > 0) {
-      TrimDescriptorArray(heap, this, descriptors, number_of_own_descriptors);
-      DCHECK(descriptors->number_of_descriptors() == number_of_own_descriptors);
-      set_owns_descriptors(true);
-    } else {
-      DCHECK(descriptors == GetHeap()->empty_descriptor_array());
-    }
-  }
-
-  // Note that we never eliminate a transition array, though we might right-trim
-  // such that number_of_transitions() == 0. If this assumption changes,
-  // TransitionArray::CopyInsert() will need to deal with the case that a
-  // transition array disappeared during GC.
-  int trim = t->number_of_transitions() - transition_index;
-  if (trim > 0) {
-    heap->RightTrimFixedArray<Heap::FROM_GC>(t, t->IsSimpleTransition()
-        ? trim : trim * TransitionArray::kTransitionSize);
-  }
-  DCHECK(HasTransitionArray());
-}
-
-
 int Map::Hash() {
   // For performance reasons we only hash the 3 most variable fields of a map:
   // constructor, prototype and bit_field2.