LibJS: Add fast path for Array.length in the bytecode interpreter

13.8% speed-up on Kraken/ai-astar.js in interpreter mode. :^)
This commit is contained in:
Andreas Kling 2024-01-27 20:37:45 +01:00
parent 514af065a5
commit 9fcd6776cf

View file

@ -84,6 +84,11 @@ inline ThrowCompletionOr<Value> get_by_id(VM& vm, DeprecatedFlyString const& pro
auto base_obj = TRY(base_object_for_get(vm, base_value));
// OPTIMIZATION: Fast path for the magical "length" property on Array objects.
if (base_obj->has_magical_length_property() && property == vm.names.length.as_string()) {
return Value { base_obj->indexed_properties().array_like_size() };
}
// OPTIMIZATION: If the shape of the object hasn't changed, we can use the cached property offset.
auto& shape = base_obj->shape();
if (&shape == cache.shape) {