https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109758
--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #8) > If the builtin isn't supported, perhaps we could use bit_cast if supported > to toggle the sign bit if we know where it is, but if that isn't supported > either, there is nothing we can do, as the function needs to be constexpr. The implementation of fabsq in libquadmath just assumes the sign bit is the MSB so it seems reasonable to do that here too. I already have a patch doing that which I'll finish testing when back at work.
