InCSetState::is_in_cset_or_humongous unnecessarily depends on the structure of the InCSetState enum. That is, the function is hardcoded to check if _value != NotInCSet instead of doing the check is_in_cset() || is_humongous(). The motivation for this implementation was performance, but careful performance measurement shows no improvement of using _value != NotInCSet version compared to check_is_in_cset() || is_humongous().