#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>

#define M (4*500000000)
#define N 4

static volatile int count = 0;
static int *res;

static int do_calc (int x)
{
    int res;

    res = x ^ (x >> 16);
    res *= 0xcafebabe;
    res = res ^ (x >> 8);
    res *= 0xfeedabba;
    return res;
}

void* start (void *arg)
{
    int start, len, i;

    start = __sync_add_and_fetch (&count, 1);
    len = M / N;
    start = (start-1)*len;

    for (i = start; i < start+len; i++) res[i] = do_calc(i);
    return NULL;
}

int main ()
{
    int i;
    pthread_t threads[N];
    res = malloc (sizeof(int)*M);

    //start(NULL);
    for (i = 0; i < N; i++)
        pthread_create (&(threads[i]), NULL, start, NULL);
    for (i = 0; i < N; i++)
        pthread_join (threads[i], NULL);

    printf ("%i\n", count);
    /* for (i=0; i<M; i++) */
    /*     if (do_calc(i) != res[i]) printf ("%i %i\n", do_calc(i), res[i]); */
    free (res);

    return 0;
}