https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55295
--- Comment #18 from Oleg Endo <olegendo at gcc dot gnu.org> --- A rather recent case and request to add a __builtin_fipr function, when trying to optimize quaternion multiplication. This one includes hand-written inline asm and register pre-allocation. https://godbolt.org/z/EsbP3KTbs