adi.c

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/* adi.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 "adi.h"


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

  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++)
      {
        u[i][j] =  (DATA_TYPE)(i + n-j) / 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(u,N,N,n,n))

{
  int i, j;

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


/* Main computational kernel. The whole function will be timed,
   including the call and return. */
/* Based on a Fortran code fragment from Figure 5 of
 * "Automatic Data and Computation Decomposition on Distributed Memory Parallel Computers"
 * by Peizong Lee and Zvi Meir Kedem, TOPLAS, 2002
 */
__attribute__((noinline))
void kernel_adi(int tsteps, int n,
                DATA_TYPE POLYBENCH_2D(u,N,N,n,n),
                DATA_TYPE POLYBENCH_2D(v,N,N,n,n),
                DATA_TYPE POLYBENCH_2D(p,N,N,n,n),
                DATA_TYPE POLYBENCH_2D(q,N,N,n,n))
{
  int t, i, j;
  DATA_TYPE DX, DY, DT;
  DATA_TYPE B1, B2;
  DATA_TYPE mul1, mul2;
  DATA_TYPE a, b, c, d, e, f;

#pragma scop

  DX = SCALAR_VAL(1.0)/(DATA_TYPE)_PB_N;
  DY = SCALAR_VAL(1.0)/(DATA_TYPE)_PB_N;
  DT = SCALAR_VAL(1.0)/(DATA_TYPE)_PB_TSTEPS;
  B1 = SCALAR_VAL(2.0);
  B2 = SCALAR_VAL(1.0);
  mul1 = B1 * DT / (DX * DX);
  mul2 = B2 * DT / (DY * DY);

  a = -mul1 /  SCALAR_VAL(2.0);
  b = SCALAR_VAL(1.0)+mul1;
  c = a;
  d = -mul2 / SCALAR_VAL(2.0);
  e = SCALAR_VAL(1.0)+mul2;
  f = d;

 for (t=1; t<=_PB_TSTEPS; t++) {
    //Column Sweep
    for (i=1; i<_PB_N-1; i++) {
      v[0][i] = SCALAR_VAL(1.0);
      p[i][0] = SCALAR_VAL(0.0);
      q[i][0] = v[0][i];
      for (j=1; j<_PB_N-1; j++) {
        p[i][j] = -c / (a*p[i][j-1]+b);
        q[i][j] = (-d*u[j][i-1]+(SCALAR_VAL(1.0)+SCALAR_VAL(2.0)*d)*u[j][i] - f*u[j][i+1]-a*q[i][j-1])/(a*p[i][j-1]+b);
      }

      v[_PB_N-1][i] = SCALAR_VAL(1.0);
      for (j=_PB_N-2; j>=1; j--) {
        v[j][i] = p[i][j] * v[j+1][i] + q[i][j];
      }
    }
    //Row Sweep
    for (i=1; i<_PB_N-1; i++) {
      u[i][0] = SCALAR_VAL(1.0);
      p[i][0] = SCALAR_VAL(0.0);
      q[i][0] = u[i][0];
      for (j=1; j<_PB_N-1; j++) {
        p[i][j] = -f / (d*p[i][j-1]+e);
        q[i][j] = (-a*v[i-1][j]+(SCALAR_VAL(1.0)+SCALAR_VAL(2.0)*a)*v[i][j] - c*v[i+1][j]-d*q[i][j-1])/(d*p[i][j-1]+e);
      }
      u[i][_PB_N-1] = SCALAR_VAL(1.0);
      for (j=_PB_N-2; j>=1; j--) {
        u[i][j] = p[i][j] * u[i][j+1] + q[i][j];
      }
    }
  }
#pragma endscop
}


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

  /* Variable declaration/allocation. */
  POLYBENCH_2D_ARRAY_DECL(u, DATA_TYPE, N, N, n, n);
  POLYBENCH_2D_ARRAY_DECL(v, DATA_TYPE, N, N, n, n);
  POLYBENCH_2D_ARRAY_DECL(p, DATA_TYPE, N, N, n, n);
  POLYBENCH_2D_ARRAY_DECL(q, DATA_TYPE, N, N, n, n);


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

  /* Start timer. */
  polybench_start_instruments;

  /* Run kernel. */
  kernel_adi (tsteps, n, POLYBENCH_ARRAY(u), POLYBENCH_ARRAY(v), POLYBENCH_ARRAY(p), POLYBENCH_ARRAY(q));

  /* 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(u)));

  /* Be clean. */
  POLYBENCH_FREE_ARRAY(u);
  POLYBENCH_FREE_ARRAY(v);
  POLYBENCH_FREE_ARRAY(p);
  POLYBENCH_FREE_ARRAY(q);

  return 0;
}