DTV_MAX_INDEX
if (__predict_true(idx < DTV_MAX_INDEX(dtv) && dtv[idx] != NULL))
size_t to_copy = DTV_MAX_INDEX(dtv);
max_index = DTV_MAX_INDEX(tcb->tcb_dtv);
if (__predict_true(idx <= DTV_MAX_INDEX(dtv) && dtv[idx] != NULL))