DCHECK(0 <= size);
Handle<FixedArray> result =
isolate->factory()->NewUninitializedFixedArray(size + kFirstIndex);
- Handle<WeakFixedArray> casted_result = Handle<WeakFixedArray>::cast(result);
- if (initialize_from.is_null()) {
- for (int i = 0; i < result->length(); ++i) {
- result->set(i, Smi::FromInt(0));
- }
- } else {
+ int index = 0;
+ if (!initialize_from.is_null()) {
DCHECK(initialize_from->Length() <= size);
Handle<FixedArray> raw_source = Handle<FixedArray>::cast(initialize_from);
- int target_index = kFirstIndex;
- for (int source_index = kFirstIndex; source_index < raw_source->length();
- ++source_index) {
- // The act of allocating might have caused entries in the source array
- // to be cleared. Copy only what's needed.
- if (initialize_from->IsEmptySlot(source_index - kFirstIndex)) continue;
- result->set(target_index++, raw_source->get(source_index));
- }
- casted_result->set_last_used_index(target_index - 1 - kFirstIndex);
- for (; target_index < result->length(); ++target_index) {
- result->set(target_index, Smi::FromInt(0));
+ // Copy the entries without compacting, since the PrototypeInfo relies on
+ // the index of the entries not to change.
+ while (index < raw_source->length()) {
+ result->set(index, raw_source->get(index));
+ index++;
}
}
- return casted_result;
+ while (index < result->length()) {
+ result->set(index, Smi::FromInt(0));
+ index++;
+ }
+ return Handle<WeakFixedArray>::cast(result);
}