#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <omp.h>
#include <sys/time.h>
char* help = "\n\
** Reduction_OpenMP.c ** \n\
Adunarea vectorilor in OpenMP \n\
\n\
Se compileaza: \n\
gcc Reduction_OpenMP.c -o Reduction_OpenMP -fopenmp -lgomp \n\
\n\
Se lanseaza cu parametrii n, p, mod max_rep unde mod: 0 cu clauza reduction, mod = 1: cu clauza critical \n\
Implicit n = 1024, p = 1, mod = 0, max_rep = 1 \n\
\n\
./Reduction_OpenMP n p mod max_rep \n\
\n\
Se executa de max_rep ori si se mediaza timpul de executie dat in secunde \n\
care se afiseaza si se inscrie in fisierul Res_Reduction_OpenMP.txt \n";
int main(int argc, char *argv[]){
int n = 1024; // Variabila partajata dimensiune matrice
int p = 1; // Variabila partajata numar thread-uri
int mod = 0; // Mod 0: cu clauza reduction
int max_rep = 1; // Numar de repetari ale executiei
int i, q, rep;
float *a,*b; // Vectorul partajat
double sum; // Suma totala
double psum; // Suma partiala (locala)
struct timeval t1, t2;
float tp;
char *fn = "Res_Reduction_OpenMP.txt";
FILE *fp;
// Citire parametri
if (argc >= 2 && strcmp(argv[1],"-help") == 0) {
printf("%s\n",help);
return 0;
}
if (argc >= 2) n = atoi(argv[1]);
if (argc >= 3) p = atoi(argv[2]);
if (argc >= 4) mod = atoi(argv[3]);
if (argc >= 5) max_rep = atoi(argv[4]);
// Testare parametri
if (n < 2){
printf("Eroare: n < 2 \n");
exit(0);
}
if (p < 1){
printf("Eroare: p < 1 \n");
exit(0);
}
if (max_rep < 1){
printf("Eroare: max_rep < 1 \n");
exit(0);
}
// Alocarea datelor
a = (float*)malloc(sizeof(float)*n);
b = (float*)malloc(sizeof(float)*n);
// Initializarea vectorului de date
for (i = 0; i < n; i++) {
a[i] = 1;
b[i] = 1;
}
gettimeofday(&t1, NULL);
for (rep = 0; rep < max_rep; rep++)
{
sum = 0.0;
if (p == 1) {
// Reducerea secventiala
for (i = 0; i < n; i++)
sum += a[i]*b[i];
}
else if (mod == 0)
// Reducerea paralela cu clauza reduction
#pragma omp parallel num_threads(p) shared(a, b,sum) private(i)
{
#pragma omp for reduction(+:sum) nowait
for(i = 0; i < n; i++)
sum += a[i]*b[i];
}
else if (mod == 1)
// Reducerea paralela cu clauza critical
#pragma omp parallel num_threads(p) shared(a,b,sum) private(i, psum)
{
psum = 0.0;
#pragma omp for nowait
for(i = 0; i < n; i++)
psum += a[i]*b[i];
#pragma omp critical
sum += psum;
}
else {
printf("Eroare mod = %d - inexistent\n", mod);
exit (0);
}
} // end for (rep)
gettimeofday(&t2, NULL);
tp = ((float)(t2.tv_sec - t1.tv_sec) + 0.000001*(t2.tv_usec - t1.tv_usec))/max_rep;
// Scriere timp de executie in fisier
fp = fopen(fn, "a");
if (p == 1) fprintf(fp, "\n%f ",tp);
else fprintf(fp, "%f ",tp);
fclose(fp);
// Afisare timp executie mediat pe max_rep teste
printf("%d rep, sum = %f, mod = %d, n = %d, p = %d, t = %f sec\n", max_rep, sum, mod, n, p, tp);
return 0;
}