usr/src/lib/libc/string/swab.c

/*      swab.c  4.2     83/06/27        */

/*
 * Swab bytes
 * Jeffrey Mogul, Stanford
 */

swab(from, to, n)
        register char *from, *to;
        register int n;
{
        register unsigned long temp;

        n >>= 1; n++;
#define STEP    temp = *from++,*to++ = *from++,*to++ = temp
        /* round to multiple of 8 */
        while ((--n) & 07)
                STEP;
        n >>= 3;
        while (--n >= 0) {
                STEP; STEP; STEP; STEP;
                STEP; STEP; STEP; STEP;
        }
}