Function qsort

sys/vms/oldcrtl.c:174–206

(base, count, size, compare)

extern void free();

void
qsort(base, count, size, compare)
char *base;
int count;
REG int size;
int (*compare)();
{
    REG int i, cmp;
    REG char *next, *prev, *tmp = 0;
    char wrk_buf[512];

    /* just use a shuffle sort (tradeoff between efficiency & simplicity) */
    /*  [Optimal if already sorted; worst case when initially reversed.]  */
    for (next = base, i = 1; i < count; i++) {
        prev = next, next += size; /* increment front pointer */
        if ((cmp = (*compare)(next, prev)) < 0) {
            /* found element out of order; move other(s) up then re-insert it
             */
            if (!tmp)
                tmp = size > (int) (sizeof wrk_buf) ? malloc(size) : wrk_buf;
            memcpy(tmp, next, size); /* save smaller element */
            while (cmp < 0) {
                memcpy(prev + size, prev, size); /* move larger elem. up */
                prev -= size;                    /* decrement back pointer */
                cmp = (prev >= base ? (*compare)(tmp, prev) : 0);
            }
            memcpy(prev + size, tmp, size); /* restore small element */
        }
    }
    if (tmp != 0 && tmp != wrk_buf)
        free(tmp);
    return;
}
#endif /*!SUPPRESS_QSORT*/

#endif /*VERYOLD_VMS*/