uint8_t *buf;
int buf_pos;
int buf_bit_pos;

int get_bit()
{
    if (buf_pos==-1)
        return -1; // end

    int rt=(buf[buf_pos] >> buf_bit_pos) & 1;
    if (buf_bit_pos==0)
    {
        buf_pos--;
        buf_bit_pos=7;
    }
    else
        buf_bit_pos--;
    return rt;
};

uint32_t remainder_arith(uint32_t dividend, uint32_t divisor)
{
    buf=(uint8_t*)&dividend;
    buf_pos=3;
    buf_bit_pos=7;

    uint32_t tmp=0;

    for(;;)
    {
        int bit=get_bit();
        if (bit==-1)
        {
            printf ("exit. remainder=%d\n", tmp);
            return tmp;
        };

        tmp=tmp<<1;
        tmp=tmp|bit;

        if (tmp>=divisor)
        {
            printf ("%d greater or equal to %d\n", tmp, divisor);
            tmp=tmp-divisor;
            printf ("new tmp=%d\n", tmp);
        }
        else
            printf ("tmp=%d, can't subtract\n", tmp);
    };
}