hpc-2022-g3/OpenMP/medley/floyd-warshall/floyd-warshall.c

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <math.h>

/* Include polybench common header. */
#include <polybench.h>

/* Include benchmark-specific header. */
/* Default data type is double, default size is 1024. */
#include "floyd-warshall.h"

/* Array initialization. */
static void init_array(int n,
                       DATA_TYPE POLYBENCH_2D(path, N, N, n, n))
{
  int i, j;

  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++)
      path[i][j] = ((DATA_TYPE)(i + 1) * (j + 1)) / n;
}

/* DCE code. Must scan the entire live-out data.
   Can be used also to check the correctness of the output. */
static void print_array(int n,
                        DATA_TYPE POLYBENCH_2D(path, N, N, n, n))

{
  int i, j;

  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++)
    {
      fprintf(stderr, DATA_PRINTF_MODIFIER, path[i][j]);
      if ((i * n + j) % 20 == 0)
        fprintf(stderr, "\n");
    }
  fprintf(stderr, "\n");
}

/* Main computational kernel. The whole function will be timed,
   including the call and return. */
static void kernel_floyd_warshall(int n,
                                  DATA_TYPE POLYBENCH_2D(path, N, N, n, n))
{
  int i, j, k;
  DATA_TYPE path_new, path_old;

  for (k = 0; k < _PB_N; k++)
  {
#pragma omp for shared(k) private(j)
    for (i = 0; i < _PB_N; i++)
      for (j = 0; j < _PB_N; j++)
      {
        path_old = path[i][j];
        path_new = path[i][k] + path[k][j];
        path[i][j] = (path[i][j] < path_new)
                         ? path[i][j]
                         : path_new;
      }
  }
}

int main(int argc, char **argv)
{
  /* Retrieve problem size. */
  int n = N;

  /* Variable declaration/allocation. */
  POLYBENCH_2D_ARRAY_DECL(path, DATA_TYPE, N, N, n, n);

  /* Initialize array(s). */
  init_array(n, POLYBENCH_ARRAY(path));

  /* Start timer. */
  polybench_start_instruments;

  /* Run kernel. */
  kernel_floyd_warshall(n, POLYBENCH_ARRAY(path));

  /* Stop and print timer. */
  polybench_stop_instruments;
  polybench_print_instruments;

  /* Prevent dead-code elimination. All live-out data must be printed
     by the function call in argument. */
  polybench_prevent_dce(print_array(n, POLYBENCH_ARRAY(path)));

  /* Be clean. */
  POLYBENCH_FREE_ARRAY(path);

  return 0;
}