Remove redudant deleted_count argument from EnqueueSpliceRecord

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index ca1c65065085d084378cde64d4a7d76550af67da..5b9c37278c13f92c731c640fd3950ffdb8a95566 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -10845,24 +10845,18 @@ static bool GetOldValue(Isolate* isolate,
   return true;
 }
 
-
-// TODO(rafaelw): Remove |delete_count| argument and rely on the length of
-// of |deleted|.
 static void EnqueueSpliceRecord(Handle<JSArray> object,
                                 uint32_t index,
                                 Handle<JSArray> deleted,
-                                uint32_t delete_count,
                                 uint32_t add_count) {
   Isolate* isolate = object->GetIsolate();
   HandleScope scope(isolate);
   Handle<Object> index_object = isolate->factory()->NewNumberFromUint(index);
-  Handle<Object> delete_count_object =
-      isolate->factory()->NewNumberFromUint(delete_count);
   Handle<Object> add_count_object =
       isolate->factory()->NewNumberFromUint(add_count);
 
   Handle<Object> args[] =
-      { object, index_object, deleted, delete_count_object, add_count_object };
+      { object, index_object, deleted, add_count_object };
 
   bool threw;
   Execution::Call(Handle<JSFunction>(isolate->observers_enqueue_splice()),
@@ -10973,7 +10967,10 @@ MaybeObject* JSArray::SetElementsLength(Object* len) {
     }
   }
 
-  EnqueueSpliceRecord(self, index, deleted, delete_count, add_count);
+  SetProperty(deleted, isolate->factory()->length_string(),

[adamk, 2013/06/05 17:22:03]

This can go inside the if (delete_count) block.

I also wonder if the thing you actually want is a static, handlified version of
JSArray::SetElementsLength, which will short-circuit the whole property-setting
machinery.

[rafaelw, 2013/06/06 18:44:41]

Done.
Yeah. Let's wait and see if this shows up as a bottle neck.

+              isolate->factory()->NewNumberFromUint(delete_count),
+              NONE, kNonStrictMode);
+  EnqueueSpliceRecord(self, index, deleted, add_count);
 
   return *hresult;
 }
@@ -12039,7 +12036,7 @@ MaybeObject* JSObject::SetElement(uint32_t index,
                           old_length_handle);
       EndPerformSplice(Handle<JSArray>::cast(self));
       Handle<JSArray> deleted = isolate->factory()->NewJSArray(0);
-      EnqueueSpliceRecord(Handle<JSArray>::cast(self), old_length, deleted, 0,
+      EnqueueSpliceRecord(Handle<JSArray>::cast(self), old_length, deleted,
                           new_length - old_length);
     } else {
       EnqueueChangeRecord(self, "new", name, old_value);