TransitionArray now uses <is_data_property, name, attributes> tuple as a key, which allows to have …

src/transitions.cc

Index: src/transitions.cc
diff --git a/src/transitions.cc b/src/transitions.cc
index 96ed870e07b43465bccef7b29abe24b7305f246e..56d9bf760d95acd0bd22e64cb1858ee1ffd4da20 100644
--- a/src/transitions.cc
+++ b/src/transitions.cc
@@ -96,7 +96,16 @@ Handle<TransitionArray> TransitionArray::CopyInsert(Handle<Map> map,
   int number_of_transitions = map->transitions()->number_of_transitions();
   int new_size = number_of_transitions;
 
-  int insertion_index = map->transitions()->Search(*name);
+  bool is_special_transition = IsSpecialTransition(*name);
+  PropertyDetails details = is_special_transition
+                                ? PropertyDetails(NONE, NORMAL, 0)
+                                : GetTargetDetails(*name, *target);
+
+  int insertion_index =
+      is_special_transition
+          ? map->transitions()->SearchSpecial(Symbol::cast(*name))
+          : map->transitions()->Search(details.type(), *name,
+                                       details.attributes());
   if (insertion_index == kNotFound) ++new_size;
 
   Handle<TransitionArray> result = Allocate(map->GetIsolate(), new_size);
@@ -113,7 +122,11 @@ Handle<TransitionArray> TransitionArray::CopyInsert(Handle<Map> map,
     number_of_transitions = array->number_of_transitions();
     new_size = number_of_transitions;
 
-    insertion_index = array->Search(*name);
+    insertion_index =
+        is_special_transition
+            ? map->transitions()->SearchSpecial(Symbol::cast(*name))
+            : map->transitions()->Search(details.type(), *name,
+                                         details.attributes());
     if (insertion_index == kNotFound) ++new_size;
 
     result->Shrink(ToKeyIndex(new_size));
@@ -129,6 +142,9 @@ Handle<TransitionArray> TransitionArray::CopyInsert(Handle<Map> map,
         result->NoIncrementalWriteBarrierCopyFrom(array, i, i);
       }
     }
+
+    DCHECK_NE(map->instance_descriptors(),
+              array->GetTarget(insertion_index)->instance_descriptors());
     result->NoIncrementalWriteBarrierSet(insertion_index, *name, *target);
     result->set_back_pointer_storage(array->back_pointer_storage());
     return result;
@@ -153,4 +169,35 @@ Handle<TransitionArray> TransitionArray::CopyInsert(Handle<Map> map,
 }
 
 
+int TransitionArray::SearchNext(int transition, PropertyType type, Name* name,
+                                PropertyAttributes attributes) {
+  int nof_transitions = number_of_transitions();
+  bool is_data = type == FIELD || type == CONSTANT;
+  for (;;) {
+    Map* target = GetTarget(transition);
+    PropertyDetails target_details = GetTargetDetails(name, target);
+    bool target_is_data =
+        target_details.type() == FIELD || target_details.type() == CONSTANT;
+
+    if (target_is_data == is_data &&
+        target_details.attributes() == attributes) {
+      return transition;
+    }
+    transition++;
+    if ((transition >= nof_transitions) || !GetKey(transition)->Equals(name)) {
+      break;
+    }
+  }
+  return kNotFound;
+}
+
+
+int TransitionArray::Search(PropertyType type, Name* name,
+                            PropertyAttributes attributes) {
+  int transition = SearchFirst(name);
+  if (transition == kNotFound) {
+    return kNotFound;
+  }
+  return SearchNext(transition, type, name, attributes);
+}
 } }  // namespace v8::internal