Programming Techniques

#define USHRT_MAX       ((u16)(~0U))
#define SHRT_MAX        ((s16)(USHRT_MAX>>1))
#define SHRT_MIN        ((s16)(-SHRT_MAX - 1))
#define INT_MAX         ((int)(~0U>>1))
#define INT_MIN         (-INT_MAX - 1)

do {                          /* count > 0 assumed */
    *to = *from++;            /* Note that the 'to' pointer is NOT incremented */
} while(--count > 0);

send(to, from, count)
register short *to, *from;
register count;
{
        register n = (count + 7) / 8;
        switch(count % 8) {
        case 0: do {    *to = *from++;
        case 7:         *to = *from++;
        case 6:         *to = *from++;
        case 5:         *to = *from++;
        case 4:         *to = *from++;
        case 3:         *to = *from++;
        case 2:         *to = *from++;
        case 1:         *to = *from++;
                } while(--n > 0);
        }
}