gramschmidt.c

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/* gramschmidt.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 "gramschmidt.h"


/* Array initialization. */
static
void init_array(int m, int n,
                DATA_TYPE POLYBENCH_2D(A,M,N,m,n),
                DATA_TYPE POLYBENCH_2D(R,N,N,n,n),
                DATA_TYPE POLYBENCH_2D(Q,M,N,m,n))
{
  int i, j;

  for (i = 0; i < m; i++)
    for (j = 0; j < n; j++) {
      A[i][j] = (((DATA_TYPE) ((i*j) % m) / m )*100) + 10;
      Q[i][j] = 0.0;
    }
  for (i = 0; i < n; i++)
    for (j = 0; j < n; j++)
      R[i][j] = 0.0;
}


/* 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 m, int n,
                 DATA_TYPE POLYBENCH_2D(A,M,N,m,n),
                 DATA_TYPE POLYBENCH_2D(R,N,N,n,n),
                 DATA_TYPE POLYBENCH_2D(Q,M,N,m,n))
{
  int i, j;

  POLYBENCH_DUMP_START;
  POLYBENCH_DUMP_BEGIN("R");
  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, R[i][j]);
    }
  POLYBENCH_DUMP_END("R");

  POLYBENCH_DUMP_BEGIN("Q");
  for (i = 0; i < m; 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, Q[i][j]);
    }
  POLYBENCH_DUMP_END("Q");
  POLYBENCH_DUMP_FINISH;
}


/* Main computational kernel. The whole function will be timed,
   including the call and return. */
/* QR Decomposition with Modified Gram Schmidt:
 http://www.inf.ethz.ch/personal/gander/ */
__attribute__((noinline))
void kernel_gramschmidt(int m, int n,
                        DATA_TYPE POLYBENCH_2D(A,M,N,m,n),
                        DATA_TYPE POLYBENCH_2D(R,N,N,n,n),
                        DATA_TYPE POLYBENCH_2D(Q,M,N,m,n))
{
  int i, j, k;

  DATA_TYPE nrm;

#pragma scop
  for (k = 0; k < _PB_N; k++)
    {
      nrm = SCALAR_VAL(0.0);
      for (i = 0; i < _PB_M; i++)
        nrm += A[i][k] * A[i][k];
      R[k][k] = SQRT_FUN(nrm);
      for (i = 0; i < _PB_M; i++)
        Q[i][k] = A[i][k] / R[k][k];
      for (j = k + 1; j < _PB_N; j++)
        {
          R[k][j] = SCALAR_VAL(0.0);
          for (i = 0; i < _PB_M; i++)
            R[k][j] += Q[i][k] * A[i][j];
          for (i = 0; i < _PB_M; i++)
            A[i][j] = A[i][j] - Q[i][k] * R[k][j];
        }
    }
#pragma endscop

}


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

  /* Variable declaration/allocation. */
  POLYBENCH_2D_ARRAY_DECL(A,DATA_TYPE,M,N,m,n);
  POLYBENCH_2D_ARRAY_DECL(R,DATA_TYPE,N,N,n,n);
  POLYBENCH_2D_ARRAY_DECL(Q,DATA_TYPE,M,N,m,n);

  /* Initialize array(s). */
  init_array (m, n,
              POLYBENCH_ARRAY(A),
              POLYBENCH_ARRAY(R),
              POLYBENCH_ARRAY(Q));

  /* Start timer. */
  polybench_start_instruments;

  /* Run kernel. */
  kernel_gramschmidt (m, n,
                      POLYBENCH_ARRAY(A),
                      POLYBENCH_ARRAY(R),
                      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(m, n, POLYBENCH_ARRAY(A), POLYBENCH_ARRAY(R), POLYBENCH_ARRAY(Q)));

  /* Be clean. */
  POLYBENCH_FREE_ARRAY(A);
  POLYBENCH_FREE_ARRAY(R);
  POLYBENCH_FREE_ARRAY(Q);

  return 0;
}