Promoting elements transitions to their own field.

src/factory.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 97 matching lines @@
   ASSERT(0 <= at_least_space_for);
   CALL_HEAP_FUNCTION(isolate(),
                      ObjectHashTable::Allocate(at_least_space_for),
                      ObjectHashTable);
 }
 
 
 Handle<DescriptorArray> Factory::NewDescriptorArray(int number_of_descriptors) {
   ASSERT(0 <= number_of_descriptors);
   CALL_HEAP_FUNCTION(isolate(),
-                     DescriptorArray::Allocate(number_of_descriptors),
+                     DescriptorArray::Allocate(number_of_descriptors,
+                                               DescriptorArray::MAY_BE_SHARED),
                      DescriptorArray);
 }
 
 
 Handle<DeoptimizationInputData> Factory::NewDeoptimizationInputData(
     int deopt_entry_count,
     PretenureFlag pretenure) {
   ASSERT(deopt_entry_count > 0);
   CALL_HEAP_FUNCTION(isolate(),
                      DeoptimizationInputData::Allocate(deopt_entry_count,
@@ skipping 360 matching lines @@
       copy->inobject_properties() + extra_inobject_properties;
   copy->set_inobject_properties(inobject_properties);
   copy->set_unused_property_fields(inobject_properties);
   copy->set_instance_size(copy->instance_size() + instance_size_delta);
   copy->set_visitor_id(StaticVisitorBase::GetVisitorId(*copy));
   return copy;
 }
 
 
 Handle<Map> Factory::CopyMapDropTransitions(Handle<Map> src) {
-  CALL_HEAP_FUNCTION(isolate(), src->CopyDropTransitions(), Map);
+  CALL_HEAP_FUNCTION(isolate(),
+                     src->CopyDropTransitions(DescriptorArray::MAY_BE_SHARED),
+                     Map);
 }
 
 
 Handle<Map> Factory::GetElementsTransitionMap(
     Handle<JSObject> src,
     ElementsKind elements_kind) {
   Isolate* i = isolate();
   CALL_HEAP_FUNCTION(i,
                      src->GetElementsTransitionMap(i, elements_kind),
                      Map);
@@ skipping 422 matching lines @@
   // Fill in new callback descriptors.  Process the callbacks from
   // back to front so that the last callback with a given name takes
   // precedence over previously added callbacks with that name.
   for (int i = nof_callbacks - 1; i >= 0; i--) {
     Handle<AccessorInfo> entry =
         Handle<AccessorInfo>(AccessorInfo::cast(callbacks.get(i)));
     // Ensure the key is a symbol before writing into the instance descriptor.
     Handle<String> key =
         SymbolFromString(Handle<String>(String::cast(entry->name())));
     // Check if a descriptor with this name already exists before writing.
-    if (result->LinearSearch(*key, descriptor_count) ==
+    if (result->LinearSearch(EXPECT_UNSORTED, *key, descriptor_count) ==
         DescriptorArray::kNotFound) {
       CallbacksDescriptor desc(*key, *entry, entry->property_attributes());
       result->Set(descriptor_count, &desc, witness);
       descriptor_count++;
     } else {
       duplicates++;
     }
   }
 
   // If duplicates were detected, allocate a result of the right size
@@ skipping 527 matching lines @@
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return Handle<Object>(value
                         ? isolate()->heap()->true_value()
                         : isolate()->heap()->false_value());
 }
 
 
 } }  // namespace v8::internal