timersub
timersub(t1, t0, &td);
timersub(&ru1.ru_utime, &ru0.ru_utime, &usrtime);
timersub(&ru1.ru_stime, &ru0.ru_stime, &systime);
timersub(&j->usrtime, &ru0.ru_utime, &j->usrtime);
timersub(&j->systime, &ru0.ru_stime, &j->systime);
timersub(&stop.ru_utime, &start.ru_utime, &res);
timersub(&ev->ev_timeout, &now, &res);
timersub(&ev->ev_timeout, &now, tv);
#define evutil_timersub(tvp, uvp, vvp) timersub((tvp), (uvp), (vvp))
timersub(&monostop, &monostart, &elapsed);
timersub(&realstop, &elapsed, &realstart);
timersub(&tv, &stv, &tv);
timersub(&tv, &stv, &tv);
timersub(&stv, &tv, &tv);
timersub(&stop, &start, &stop);
timersub(&stop, &start, &stop);
timersub(&stop, &start, &stop);
timersub(&now, &sc->sc_lastpoll, &diff);
timersub(guest, &host, &diff);
timersub(guest, &host, &diff);
timersub(&curtime, &sc->sc_lastbpschange, &curtime);
timersub(&now, &sc->sc_ptime, &waited);
timersub(&end, &start, &elapsed);
timersub(&tv, lasttime, &delta);
timersub(&tv, lasttime, &delta);
timersub(&dv_time, &diskp->dk_timestamp, &diff_time);
timersub(&uptime, &src->scrub->pfss_last, &delta_ts);
timersub(&now, &ic->ic_edca_txop_time[ac], &delta);
timersub(&now.ru_utime, &start, &elapsed);
timersub(&finish, start, &diff);
timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
timersub(&tv_now, &tv_start, &tv_delta);
timersub(&t_cur, &mainstats.t_first, &t_diff);
timersub(&t_cur, &sc->t_start, &t_diff);
timersub(&t_cur, &sc->t_last, &t_diff);
timersub(&t_cur, &udp_sc->t_start, &t_diff);
timersub(&t_cur, &udp_sc->t_last, &t_diff);
timersub(tv, &w->name_time, &offset);
timersub(&c->activity_time, &c->last_activity_time, &tv);
timersub(&c->activity_time, &c->keytable->activity_time, &diff);
timersub(&tmp_timer, &last.dk_time[i], &cur.dk_time[i]);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now2, &res);
timersub(&tv, &now2, &res);
timersub(&tv_now, start, &tv_now);
timersub(&tv_next, &tv_now, &tv_next);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&tv, &now, &res);
timersub(&now, &session->se_tv_start, &tv);
timersub(&now, &session->se_tv_last, &tv);
timersub(&tv_now, &host->cte.tv_start, &tv_dur);
timersub(&tv_now, &con->se_tv_last, &tv);
timersub(&tv_now, start, &tv_now);
timersub(&tv_next, &tv_now, &tv_next);
timersub(a, b, &tv);
timersub(&tv, &now, &res);
timersub(&cur, &last, &diff);
timersub(&tv, &vm->vm_start_tv, &since_last);
timersub(&now, &delay, &max_date);