void _24to32( SV* packed ) {
    IS_VARS;
    char *pp = SvPVX( packed );
    _4BY6 up;
    int i;

    IS_RESET;
    for( i=0; i<24; i+=3 ) {
        up.packed = _byteswap_ulong( *(unsigned long*)&pp[ i ] );
        IS_PUSHUV( up.u.a );
        IS_PUSHUV( up.u.b );
        IS_PUSHUV( up.u.c );
        IS_PUSHUV( up.u.d );
    }
    IS_DONE;
    return;
}