Function main

deps/GraphBLAS/Demo/InProgress/gpu_reduce_demo.c:17–125

   #define N 16384

int main (void)
{

    #if defined ( _OPENMP )
    double t0 = omp_get_wtime ( ) ;
    #endif

    // start GraphBLAS
    GrB_init (GrB_NONBLOCKING) ;
    printf ("demo: reduce a matrix to a scalar\n") ;

    int nthreads_max ;
    GxB_get (GxB_NTHREADS, &nthreads_max) ;
    printf ("# of threads: %d\n", nthreads_max) ;

    #if defined ( _OPENMP )
    t0 = omp_get_wtime ( ) - t0 ;
    printf ("GPU warmup time: %g\n", t0) ;
    t0 = omp_get_wtime ( ) ;
    #endif

    GrB_Index nrows = N ;
    GrB_Index ncols = N ;
    GrB_Matrix A ;
    GrB_Matrix_new (&A, GrB_INT64, nrows, ncols) ;

    GrB_Index *I = malloc (nrows * ncols * sizeof (GrB_Index)) ;
    GrB_Index *J = malloc (nrows * ncols * sizeof (GrB_Index)) ;
    int64_t   *X = malloc (nrows * ncols * sizeof (int64_t)) ;

    #pragma omp parallel for num_threads(nthreads_max) collapse(2) \
        schedule(static)
    for (int64_t i = 0 ; i < nrows ; i++)
    {
        for (int64_t j = 0 ; j < ncols ; j++)
        {
            int64_t k = i * N + j ;
            // int x = (int) (rand ( ) & 0xFF) ;
            int x = (int) (k & 0xFF) ;
            I [k] = i ;
            J [k] = j ;
            X [k] = x ;
        }
    }

    GrB_Index nvals = ((size_t) N) * ((size_t) N) ;
    GrB_Matrix_build (A, I, J, X, nvals, GrB_PLUS_INT64) ;

    GxB_print (A, 2) ;

    free (I) ;
    free (J) ;
    free (X) ;

    #if defined ( _OPENMP )
    t0 = omp_get_wtime ( ) - t0 ;
    printf ("time to create matrix: %g\n", t0) ;
    #endif