for.c

#include <stdio.h>
#include <time.h>
#include <omp.h>

int main()
{
        unsigned long long l = 0, a = 0;
        clock_t start, stop;

        start = clock();
#pragma omp parallel for private(l, a)
        for(l = 0; l < 0x3b9aca00ULL; ++l) a += l;
        stop = clock();

        printf("%ld ms\n", (long)(stop - start) * 1000 / CLOCKS_PER_SEC);
        printf("a = 0x%0llx, l = 0x%0llx\n", a, l);
        return 0;
}