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LibJS: Add fast path in ArrayIteratorPrototype::next()

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When iterating over vanilla objects/arrays with normal property storage,
we can skip the generic Get mechanism in favor of looking directly at
property storage. This is essentially what we do in the bytecode path.
This commit is contained in:
Andreas Kling 2023-12-08 12:50:44 +01:00
parent 373ec387c1
commit d8be9ebc16
1 changed files with 10 additions and 1 deletions
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11
Userland/Libraries/LibJS/Runtime/ArrayIteratorPrototype.cpp
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@ -70,7 +70,16 @@ JS_DEFINE_NATIVE_FUNCTION(ArrayIteratorPrototype::next)
if (iteration_kind == Object::PropertyKind::Key)
return create_iterator_result_object(vm, Value(static_cast<i32>(index)), false);
auto value = TRY(array.get(index));
auto value = TRY([&]() -> ThrowCompletionOr<Value> {
// OPTIMIZATION: For objects that don't interfere with indexed property access, we try looking directly at storage.
if (!array.may_interfere_with_indexed_property_access() && array.indexed_properties().has_index(index)) {
auto value = array.indexed_properties().get(index)->value;
if (!value.is_accessor()) {
return value;
}
}
return array.get(index);
}());
if (iteration_kind == Object::PropertyKind::Value)
return create_iterator_result_object(vm, value, false);