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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgomp/] [testsuite/] [libgomp.c/] [nqueens-1.c] - Blame information for rev 735

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Line No. Rev Author Line
1 735 jeremybenn
/* { dg-do run } */
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/* { dg-options "-O2 -fopenmp" } */
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/* { dg-require-effective-target tls_runtime } */
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#include <omp.h>
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#include <stdio.h>
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#include <string.h>
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int cnt;
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#pragma omp threadprivate (cnt)
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void
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nqueens (char *a, int n, int pos)
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{
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  /* b[i] = j means the queen in i-th row is in column j.  */
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  char b[pos + 1];
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  int i, j;
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  memcpy (b, a, pos);
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  for (i = 0; i < n; i++)
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    {
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      for (j = 0; j < pos; j++)
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        if (b[j] == i || b[j] == i + pos - j || i == b[j] + pos - j)
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          break;
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      if (j < pos)
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        continue;
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      if (pos == n - 1)
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        /* Found a solution.  Could output it here.  */
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        ++cnt;
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      else
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        {
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          b[pos] = i;
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          #pragma omp task
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            nqueens (b, n, pos + 1);
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        }
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    }
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}
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int
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main (int argc, char **argv)
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{
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  int n = 8;
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  if (argc >= 2)
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    n = strtoul (argv[1], NULL, 0);
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  if (n < 1 || n > 127)
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    {
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      fprintf (stderr, "invalid count %d\n", n);
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      return 1;
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    }
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  cnt = 0;
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  double stime = omp_get_wtime ();
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  nqueens ("", n, 0);
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  printf ("serial   N %d solutions # %d time %f\n", n, cnt, omp_get_wtime () - stime);
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  #pragma omp parallel
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    cnt = 0;
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  stime = omp_get_wtime ();
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  int tempcnt = 0;
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  #pragma omp parallel reduction (+:tempcnt)
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    {
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      #pragma omp single
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        nqueens ("", n, 0);
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      tempcnt = cnt;
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    }
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  cnt = tempcnt;
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  printf ("parallel N %d solutions # %d time %f\n", n, cnt, omp_get_wtime () - stime);
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  return 0;
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}

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