https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108922
--- Comment #19 from Alexander Monakov <amonakov at gcc dot gnu.org> --- I get the feeling that you're ignoring me, but gcc-4.8.3 was already emitting a helper fmod call for setting errno without any flag_errno_math checks in i386.md, i.e. it was already in the middle-end. As was mentioned in comment #9.