compute_sunsum
sunsum = compute_sunsum(bb16); /* might be the final value */
if (compute_sunsum(bb16) != bb16[255])
warnx(wmsg, when, "checksum", bb16[255], compute_sunsum(bb16));
sum = compute_sunsum((uint16_t *)&bb);
sum = compute_sunsum((uint16_t *)&bb);
sum = compute_sunsum((uint16_t *)&bb);
sum = compute_sunsum((uint16_t *)bb);
uint16_t compute_sunsum(const uint16_t *);