jacobi-1d.c

Go to the documentation of this file.

/* jacobi-1d.c: this file is part of PolyBench/C */

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

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

/* Include benchmark-specific header. */
#include "jacobi-1d.h"


/* Array initialization. */
static
void init_array (int n,
                 DATA_TYPE POLYBENCH_1D(A,N,n),
                 DATA_TYPE POLYBENCH_1D(B,N,n))
{
  int i;

  for (i = 0; i < n; i++)
      {
        A[i] = ((DATA_TYPE) i+ 2) / n;
        B[i] = ((DATA_TYPE) i+ 3) / 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_1D(A,N,n))

{
  int i;

  POLYBENCH_DUMP_START;
  POLYBENCH_DUMP_BEGIN("A");
  for (i = 0; i < n; i++)
    {
      if (i % 20 == 0) fprintf(POLYBENCH_DUMP_TARGET, "\n");
      fprintf(POLYBENCH_DUMP_TARGET, DATA_PRINTF_MODIFIER, A[i]);
    }
  POLYBENCH_DUMP_END("A");
  POLYBENCH_DUMP_FINISH;
}


/* Main computational kernel. The whole function will be timed,
   including the call and return. */
__attribute__((noinline))
void kernel_jacobi_1d(int tsteps,
                            int n,
                            DATA_TYPE POLYBENCH_1D(A,N,n),
                            DATA_TYPE POLYBENCH_1D(B,N,n))
{
  int t, i;

#pragma scop
  for (t = 0; t < _PB_TSTEPS; t++)
    {
      for (i = 1; i < _PB_N - 1; i++)
        B[i] = 0.33333 * (A[i-1] + A[i] + A[i + 1]);
      for (i = 1; i < _PB_N - 1; i++)
        A[i] = 0.33333 * (B[i-1] + B[i] + B[i + 1]);
    }
#pragma endscop

}


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

  /* Variable declaration/allocation. */
  POLYBENCH_1D_ARRAY_DECL(A, DATA_TYPE, N, n);
  POLYBENCH_1D_ARRAY_DECL(B, DATA_TYPE, N, n);


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

  /* Start timer. */
  polybench_start_instruments;

  /* Run kernel. */
  kernel_jacobi_1d(tsteps, n, POLYBENCH_ARRAY(A), POLYBENCH_ARRAY(B));

  /* 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(A)));

  /* Be clean. */
  POLYBENCH_FREE_ARRAY(A);
  POLYBENCH_FREE_ARRAY(B);

  return 0;
}