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wangyu-/omp_mul.c

Forked from metallurgix/omp_mul.c
Created April 5, 2019 15:17
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Revisions

  1. @metallurgix metallurgix revised this gist Jul 15, 2014. 1 changed file with 2 additions and 2 deletions.
    4 changes: 2 additions & 2 deletions omp_mul.c
    View file
    Original file line number Diff line number Diff line change
    @@ -20,10 +20,10 @@ int main()
    omp_set_num_threads(omp_get_num_procs());
    for (i= 0; i< N; i++)
    for (j= 0; j< N; j++)
    {
    {
    A[i][j] = 2;
    B[i][j] = 2;
    }
    }
    gettimeofday(&tv1, &tz);
    #pragma omp parallel for private(i,j,k) shared(A,B,C)
    for (i = 0; i < N; ++i) {
  2. @metallurgix metallurgix created this gist Jul 15, 2014.
    51 changes: 51 additions & 0 deletions omp_mul.c
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,51 @@
    #include <pthread.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <omp.h>
    #include <sys/time.h>


    #define N 1000

    int A[N][N];
    int B[N][N];
    int C[N][N];

    int main()
    {
    int i,j,k;
    struct timeval tv1, tv2;
    struct timezone tz;
    double elapsed;
    omp_set_num_threads(omp_get_num_procs());
    for (i= 0; i< N; i++)
    for (j= 0; j< N; j++)
    {
    A[i][j] = 2;
    B[i][j] = 2;
    }
    gettimeofday(&tv1, &tz);
    #pragma omp parallel for private(i,j,k) shared(A,B,C)
    for (i = 0; i < N; ++i) {
    for (j = 0; j < N; ++j) {
    for (k = 0; k < N; ++k) {
    C[i][j] += A[i][k] * B[k][j];
    }
    }
    }


    gettimeofday(&tv2, &tz);
    elapsed = (double) (tv2.tv_sec-tv1.tv_sec) + (double) (tv2.tv_usec-tv1.tv_usec) * 1.e-6;
    printf("elapsed time = %f seconds.\n", elapsed);

    /*for (i= 0; i< N; i++)
    {
    for (j= 0; j< N; j++)
    {
    printf("%d\t",C[i][j]);
    }
    printf("\n");
    }*/
    }