void _24to32_2( SV *packed ) {
    IS_VARS;
    char *pp = SvPVX( packed );
    int i;

    IS_RESET;
    for( i=0; i<24; i+=3 ) {
        unsigned int n = _byteswap_ulong( *(unsigned long*)&pp[ i -1 ] );
        IS_PUSHUV( ( n & 0xfc0000 ) >> 18 );
        IS_PUSHUV( ( n & 0x03f000 ) >> 12 );
        IS_PUSHUV( ( n & 0x000fc0 ) >>  6 );
        IS_PUSHUV( ( n & 0x00003f )       );
    }
    IS_DONE;
    return;

}