https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54272
--- Comment #7 from Oleg Endo <olegendo at gcc dot gnu.org> --- (In reply to Oleg Endo from comment #0) > The addv and subv instructions can be used for at least two things: > > 1) Implementing trapping signed integer arithmetic (-ftrapv) > > Currently, for the SH target, trapping insns (e.g. addvsi3) are > supposed to be implemented by library functions in libgcc. > However, it seems that for addvsi3 and subvsi3 normal addsi3 and > subsi3 patterns are expanded by the middle-end, which is wrong. See also PR 52478.