BCOPY
BCOPY(ip, &cs->cs_ip, hlen);
BCOPY(new_seq, cp, deltaS);
BCOPY(ip, &cs->cs_ip, hlen);
BCOPY(cp, ((intptr_t)cp &~ 3), len);
BCOPY(hdr, cp, hlen);
BCOPY(ip, &cs->cs_ip, hlen);