mirror of
https://github.com/RGBCube/serenity
synced 2025-07-25 19:57:35 +00:00
LibJS: Stop converting between Object <-> IteratorRecord all the time
This patch makes IteratorRecord an Object. Although it's not exposed to author code, this does allow us to store it in a VM register. Now that we can store it in a VM register, we don't need to convert it back and forth between IteratorRecord and Object when accessing it from bytecode. The big win here is avoiding 3 [[Get]] accesses on every iteration step of for..of loops. There are also a bunch of smaller efficiencies gained. 20% speed-up on this microbenchmark: function go(a) { for (const p of a) { } } const a = []; a.length = 1_000_000; go(a);
This commit is contained in:
parent
4966c083df
commit
4699c81fc1
23 changed files with 226 additions and 144 deletions
|
@ -70,12 +70,12 @@ JS_DEFINE_NATIVE_FUNCTION(IteratorConstructor::from)
|
|||
auto iterator_record = TRY(get_iterator_flattenable(vm, object, StringHandling::IterateStrings));
|
||||
|
||||
// 2. Let hasInstance be ? OrdinaryHasInstance(%Iterator%, iteratorRecord.[[Iterator]]).
|
||||
auto has_instance = TRY(ordinary_has_instance(vm, iterator_record.iterator, realm.intrinsics().iterator_constructor()));
|
||||
auto has_instance = TRY(ordinary_has_instance(vm, iterator_record->iterator, realm.intrinsics().iterator_constructor()));
|
||||
|
||||
// 3. If hasInstance is true, then
|
||||
if (has_instance.is_boolean() && has_instance.as_bool()) {
|
||||
// a. Return iteratorRecord.[[Iterator]].
|
||||
return iterator_record.iterator;
|
||||
return iterator_record->iterator;
|
||||
}
|
||||
|
||||
// 4. Let wrapper be OrdinaryObjectCreate(%WrapForValidIteratorPrototype%, « [[Iterated]] »).
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue