Moving the WhitenessWitness back to DescriptorArray.

src/transitions.cc

 // Copyright 2012 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 40 matching lines @@
       heap->AllocateFixedArray(ToKeyIndex(number_of_transitions));
   if (!maybe_array->To(&array)) return maybe_array;
 
   array->set(kDescriptorsPointerIndex, descriptors_cell);
   array->set(kElementsTransitionIndex, Smi::FromInt(0));
   array->set(kPrototypeTransitionsIndex, Smi::FromInt(0));
   return array;
 }
 
 
-void TransitionArray::CopyFrom(TransitionArray* origin,
-                               int origin_transition,
-                               int target_transition,
-                               const WhitenessWitness& witness) {
-  Set(target_transition,
-      origin->GetKey(origin_transition),
-      origin->GetTarget(origin_transition),
-      witness);
+void TransitionArray::NoIncrementalWriteBarrierCopyFrom(TransitionArray* origin,
+                                                        int origin_transition,
+                                                        int target_transition) {
+  NoIncrementalWriteBarrierSet(target_transition,
+                               origin->GetKey(origin_transition),
+                               origin->GetTarget(origin_transition));
 }
 
 
 static bool InsertionPointFound(String* key1, String* key2) {
   return key1->Hash() > key2->Hash();
 }
 
 
 MaybeObject* TransitionArray::NewWith(
     String* name,
     Map* target,
     JSGlobalPropertyCell* descriptors_pointer,
     Object* back_pointer) {
   TransitionArray* result;
 
   MaybeObject* maybe_array = TransitionArray::Allocate(1, descriptors_pointer);
   if (!maybe_array->To(&result)) return maybe_array;
 
-  FixedArray::WhitenessWitness witness(result);
-
-  result->Set(0, name, target, witness);
+  result->NoIncrementalWriteBarrierSet(0, name, target);
   result->set_back_pointer_storage(back_pointer);
   return result;
 }
 
 
 MaybeObject* TransitionArray::CopyInsert(String* name, Map* target) {
   TransitionArray* result;
 
   int number_of_transitions = this->number_of_transitions();
   int new_size = number_of_transitions;
 
   int insertion_index = this->Search(name);
   if (insertion_index == kNotFound) ++new_size;
 
   MaybeObject* maybe_array;
   maybe_array = TransitionArray::Allocate(new_size, descriptors_pointer());
   if (!maybe_array->To(&result)) return maybe_array;
 
   if (HasElementsTransition()) {
     result->set_elements_transition(elements_transition());
   }
 
   if (HasPrototypeTransitions()) {
     result->SetPrototypeTransitions(GetPrototypeTransitions());
   }
 
-  FixedArray::WhitenessWitness witness(result);
-
   if (insertion_index != kNotFound) {
     for (int i = 0; i < number_of_transitions; ++i) {
-      if (i != insertion_index) result->CopyFrom(this, i, i, witness);
+      if (i != insertion_index) {
+        result->NoIncrementalWriteBarrierCopyFrom(this, i, i);
+      }
     }
-    result->Set(insertion_index, name, target, witness);
+    result->NoIncrementalWriteBarrierSet(insertion_index, name, target);
     return result;
   }
 
   insertion_index = 0;
   for (; insertion_index < number_of_transitions; ++insertion_index) {
     if (InsertionPointFound(GetKey(insertion_index), name)) break;
-    result->CopyFrom(this, insertion_index, insertion_index, witness);
+    result->NoIncrementalWriteBarrierCopyFrom(
+        this, insertion_index, insertion_index);
   }
 
-  result->Set(insertion_index, name, target, witness);
+  result->NoIncrementalWriteBarrierSet(insertion_index, name, target);
 
   for (; insertion_index < number_of_transitions; ++insertion_index) {
-    result->CopyFrom(this, insertion_index, insertion_index + 1, witness);
+    result->NoIncrementalWriteBarrierCopyFrom(
+        this, insertion_index, insertion_index + 1);
   }
 
   result->set_back_pointer_storage(back_pointer_storage());
   return result;
 }
 
 
 } }  // namespace v8::internal