Assembly Language for Beginners

3.27. OPENMP

int32_t* __max;

time_t start;

#ifdef GNUC
#define min(X,Y) ((X) < (Y)? (X) : (Y))
#define max(X,Y) ((X) > (Y)? (X) : (Y))
#endif

void check_nonce (int32_t nonce)
{
uint8_t buf[32];
struct sha512_ctx ctx;
uint8_t res[64];

// update statistics

int t=omp_get_thread_num();

if (__min[t]==-1)

__min[t]=nonce;

if (__max[t]==-1)

__max[t]=nonce;

__min[t]=min(__min[t], nonce);

__max[t]=max(__max[t], nonce);

// idle if valid nonce found

if (found)

return;

memset (buf, 0, sizeof(buf));

sprintf (buf, "hello, world!_%d", nonce);

sha512_init_ctx (&ctx);

sha512_process_bytes (buf, strlen(buf), &ctx);

sha512_finish_ctx (&ctx, &res);

if (res[0]==0 && res[1]==0 && res[2]==0)

{

printf ("found (thread %d): [%s]. seconds spent=%d\n", t, buf, time(NULL)-start⤦

Ç);

found=1;

};

#pragma omp atomic

checked++;

#pragma omp critical
if ((checked % 100000)==0)
printf ("checked=%d\n", checked);
};

int main()
{
int32_t i;
int threads=omp_get_max_threads();
printf ("threads=%d\n", threads);

__min=(int32_t*)malloc(threads*sizeof(int32_t));

__max=(int32_t*)malloc(threads*sizeof(int32_t));

for (i=0; i<threads; i++)

__min[i]=__max[i]=-1;

start=time(NULL);

#pragma omp parallel for

for (i=0; i<INT32_MAX; i++)

check_nonce (i);

for (i=0; i<threads; i++)

printf ("__min[%d]=0x%08x __max[%d]=0x%08x\n", i, __min[i], i, __max[i]);