AR_BufLen_S
checksum += (val = (i->buf_len[0] << AR_BufLen_S) & AR_BufLen);
checksum += (val = (i->buf_len[1] << AR_BufLen_S) & AR_BufLen);
checksum += (val = (i->buf_len[2] << AR_BufLen_S) & AR_BufLen);
checksum += (val = (i->buf_len[3] << AR_BufLen_S) & AR_BufLen);