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 96 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, false),
                      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(false), 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 350 matching lines @@
                      DescriptorArray);
 }
 
 
 Handle<String> Factory::SymbolFromString(Handle<String> value) {
   CALL_HEAP_FUNCTION(isolate(),
                      isolate()->heap()->LookupSymbol(*value), String);
 }
 
 
+static int LinearSearchUnsorted(DescriptorArray* descriptor_array,
+                                String* name, int len) {
+  uint32_t hash = name->Hash();
+  for (int number = 0; number < len; number++) {
+    String* entry = descriptor_array->GetKey(number);
+    if (entry->Hash() == hash &&
+        name->Equals(entry) &&
+        !descriptor_array->IsNullDescriptor(number)) {
+      return number;
+    }
+  }
+  return DescriptorArray::kNotFound;
+}
+
+
 Handle<DescriptorArray> Factory::CopyAppendCallbackDescriptors(
     Handle<DescriptorArray> array,
     Handle<Object> descriptors) {
   v8::NeanderArray callbacks(descriptors);
   int nof_callbacks = callbacks.length();
   Handle<DescriptorArray> result =
       NewDescriptorArray(array->number_of_descriptors() + nof_callbacks);
 
   // Number of descriptors added to the result so far.
   int descriptor_count = 0;
@@ skipping 14 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 (LinearSearchUnsorted(*result, *key, descriptor_count) ==

[danno, 2012/06/01 13:49:55]

Add a enum { EXPECT_SORTED, EXPECT_UNSORTED } and put both implementations in
LinearSearch on the descriptor that take the enum selector as another parameter.

[Toon Verwaest, 2012/06/04 09:17:48]

Done.

         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