https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98508
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- It is not simple at all. While the ifns don't modify the references variable, they do modify the corresponding shadow memory, which is something GCC aliasing oracle doesn't track at all, so by supplying detailed fnspec about the ifns there is a very high risk it will start miscompiling things. I have tried it in the past, and it just didn't work.
