mp_bdivmod
MP_CHECKOK(mp_bdivmod(&t, b, &meth->irr, meth->irr_arr, r));
return mp_bdivmod(a, b, &meth->irr, meth->irr_arr, r);
mp_err mp_bdivmod(const mp_int *y, const mp_int *x, const mp_int *pp,