Function gmp_mpfr_sys::gmp::__gmpn_sub_1

pub unsafe extern fn __gmpn_sub_1(__gmp_dst: mp_ptr,
                                  __gmp_src: mp_srcptr,
                                  __gmp_size: mp_size_t,
                                  __gmp_n: mp_limb_t)
                                  -> mp_limb_t