DEBUG_MSG(SUBSET,nullptr,"%c%c%c%c in src has %d advances, %d lsbs",HB_UNTAG(T::tableTag),_mtx.num_advances,_mtx.num_metrics-_mtx.num_advances);
DEBUG_MSG(SUBSET,nullptr,"%c%c%c%c in dest has %d advances, %d lsbs, %zu bytes",HB_UNTAG(T::tableTag),num_advances,gids.len-num_advances,dest_sz);
DEBUG_MSG(SUBSET,nullptr,"%c%c%c%c in dest has %d advances, %d lsbs, %u bytes",HB_UNTAG(T::tableTag),num_advances,gids.len-num_advances,(unsignedint)dest_sz);