1  #define DEBUG 0
       2  #if DEBUG
       3  #include <stdio.h>
       4  #endif
       5  
       6  int B[4];
       7  int A[4][4][4][4];
       8  
       9  static int __attribute__((noinline))
      10  foo (void)
      11  {
      12    int i, j, k, l;
      13  
      14    /* Loops (L, J) are interchanged, and then loops (J and K) are
      15       interchanged.  The result is a nest starting with (K, J, L).  */
      16    for (l = 0; l < 4; l++)
      17      {
      18        for (k = 0; k < 4; k++)
      19  	{
      20  	  for (j = 0; j < 4; j++)
      21  	    {
      22  	      for (i = 0; i < 2; i++)
      23  		{
      24  		  B[i] = A[i][k][j][l] + A[3 - i][k][j][l];
      25  		  B[3 - i] = A[i][k][j][l] - A[3 - i][k][j][l];
      26  		}
      27  	      A[0][k][j][l] = B[0] + B[1];
      28  	      A[2][k][j][l] = B[0] - B[1];
      29  	      A[1][k][j][l] = B[3] + B[2];
      30  	      A[3][k][j][l] = B[3] - B[2];
      31  	    }
      32  
      33  	  for (i = 0; i < 4; i++)
      34  	    {
      35  	      for (j = 0; j < 2; j++)
      36  		{
      37  		  B[j] = A[i][k][j][l] + A[i][k][3 - j][l];
      38  		  B[3 - j] = A[i][k][j][l] - A[i][k][3 - j][l];
      39  		}
      40  	      A[i][k][0][l] = B[0] + B[1];
      41  	      A[i][k][2][l] = B[0] - B[1];
      42  	      A[i][k][1][l] = B[3] + B[2];
      43  	      A[i][k][3][l] = B[3] - B[2];
      44  	    }
      45  	}
      46      }
      47  
      48    return A[0][1][0][2] + A[0][3][0][3] + A[0][2][0][2] + A[0][1][0][1] + A[3][3][0][2];
      49  }
      50  
      51  extern void abort ();
      52  
      53  int
      54  main (void)
      55  {
      56    int i, j, k, l, res;
      57  
      58    for (i = 0; i < 4; i++)
      59      B[i] = 2;
      60  
      61    for (i = 0; i < 4; i++)
      62      for (j = 0; j < 4; j++)
      63        for (k = 0; k < 4; k++)
      64  	for (l = 0; l < 4; l++)
      65  	  A[i][j][k][l] = i + j + k + l;
      66  
      67    res = foo ();
      68  
      69  #if DEBUG
      70    for (i = 0; i < 4; i++)
      71      for (j = 0; j < 4; j++)
      72        for (k = 0; k < 4; k++)
      73  	for (l = 0; l < 4; l++)
      74  	  fprintf (stderr, "A[%d][%d][%d][%d] = %d \n", i, j, k, l, A[i][j][k][l]);
      75  
      76    fprintf (stderr, "res = %d \n", res);
      77  #endif
      78  
      79    if (res != 424)
      80      abort ();
      81  
      82    return 0;
      83  }
      84  
      85  /* { dg-final { scan-tree-dump "tiled by" "graphite" } } */