byte to word and vise versa function

#include <stdio.h>
typedef short uint16_t;
typedef unsigned char uint8_t;
void
word_to_bytes(uint16_t num, uint8_t *byte1, uint8_t *byte2);
uint16_t
bytes_to_word(uint16_t num, uint8_t *byte1, uint8_t *byte2);
int
main()
{
        unsigned char byte1, byte2;
        uint16_t num = 0;
        word_to_bytes(1000, &byte1, &byte2);
        printf("byte1 = %d\t", byte1);
        printf("byte2 = %d\n", byte2);
        printf("num = %d\n", bytes_to_word(num, &byte1, &byte2));
        return (0);
}
void
word_to_bytes(uint16_t num, uint8_t *byte1, uint8_t *byte2)
{
        uint8_t i;
        uint16_t result = num;
        *byte1 = *byte2 = i = 0;

        while (i < 8) {
                if (result%2)
                        *byte1 |= (1 << i);
                result = result/2;
                i++;
        }
        i = 0;
        while (i < 8) {
                if (result%2)
                        *byte2 |= (1 << i);
                result = result/2;
                i++;
        }
}
uint16_t
bytes_to_word(uint16_t num, uint8_t *byte1, uint8_t *byte2)
{
        uint8_t i, j;
        i = j = 0;
        while (i < 8) {
                if (*byte1 & (1 << i))
                        num |= 1 << i;
                else
                        num &= ~(1 << i);
                i++;
        }
        i = 0;
        while (i < 8) {
                j = i + 8;
                if (*byte2 & (1 << i))
                        num |= 1 << j;
                else
                        num &= ~(1 << j);
                i++;

        }
        return (num);
}