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#ifdef USE_OMP
int openmptest(){
int start = timeOfDayinMS();
long int sum=0;
int i,j;
#pragma omp parallel for shared(sum) private(i,j)
for (i=0; i<10;i++){
printf("num theads: %i\n",omp_get_thread_num());
long int k=0;
for (j=0; j<4000000;j++){
k+=sqrt(j);
}
#pragma omp atomic
sum+=k;
}
int end = timeOfDayinMS();
fprintf(stderr, "Sum: %li\n",sum);
return end-start;
}
int openmp(){
fprintf(stderr, "Processors: %i, Max # theads: %i\n", omp_get_num_procs(), omp_get_max_threads());
int num = omp_get_max_threads();
int time, timeref;
omp_set_dynamic( 0 );
omp_set_num_threads( 1 );
fprintf(stderr,"********** omp speedtest:\n");
time = openmptest();
fprintf(stderr,"***C time: %i ms\n", time);
timeref=time;
omp_set_dynamic( 1 );
omp_set_num_threads( num);
time = openmptest();
fprintf(stderr,"***C (%i)time: %i ms, Speedup %f\n", num, time,
(double)timeref/time);
omp_set_dynamic( 1 );
return 1;
}
#endif
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