NVIDIA-GPU-Bootcamp-Training/hpc/openacc/English/C/source_code/lab3/jacobi.c

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#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <omp.h>
#include "laplace2d.h"

int main(int argc, char** argv)
{

    int n, m, iter_max;

    if(argc > 1){
        n = atoi(argv[1]);
    } else {
        n = 4096;
    }

    if(argc > 2){
        m = atoi(argv[2]);
    } else {
        m = 4096;
    }

    if(argc > 3){
        iter_max = atoi(argv[3]);
    } else {
        iter_max = 1000;
    }

    const double tol = 1.0e-6;
    double error = 1.0;

    double *restrict A    = (double*)malloc(sizeof(double)*n*m);
    double *restrict Anew = (double*)malloc(sizeof(double)*n*m);
    
    initialize(A, Anew, m, n);
        
    printf("Jacobi relaxation Calculation: %d x %d mesh\n", n, m);
    
    double st = omp_get_wtime();
    int iter = 0;
   
#pragma acc data copy(A[:n*m]) create(Anew[:n*m])
    while ( error > tol && iter < iter_max )
    {
        error = calcNext(A, Anew, m, n);
        swap(A, Anew, m, n);

        if(iter % 100 == 0) printf("%5d, %0.6f\n", iter, error);
        
        iter++;

    }

    double runtime = omp_get_wtime() - st;
 
    printf(" total: %f s\n", runtime);

    deallocate(A, Anew);

    return 0;
}