https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114222
--- Comment #5 from Jeffrey A. Law <law at gcc dot gnu.org> --- But I would say that is the core problem. ISTM newlib should provide an actual implementation of ffs rather than assuming that GCC will provide one suitable for use in all circumstances. The current code is just a poor implementation choice as it depends on GCC internals.
