IPCID_TO_IX
if (que->que_ix == IPCID_TO_IX(id))
ix = IPCID_TO_IX(semid);
semid = IPCID_TO_IX(semid); /* Convert back to zero origin */
segnum = IPCID_TO_IX(shmid);
segnum = IPCID_TO_IX(shmmap_s->shmid);
shm_last_free = IPCID_TO_IX(SCARG(uap, shmid));
shm_last_free = IPCID_TO_IX(shmid);
(shmseg = shmsegs[IPCID_TO_IX(shmmap_s->shmid)]) != NULL)