memcheck/tests/origin6-fp.c

   1
   2 /* Test of origin tracking through floating point code and in the case
   3    where there are large amounts of uninitialised data floating
   4    around.  This program creates 3 matrices of 2300x2300 doubles,
   5    makes one value in them undefined, does arithmetic, and tests the
   6    result, which is then undefined.
   7
   8    This also tests the secondary otag cache (ocacheL2), since the
   9    amount of uninitialised data is somewhat over 43MB and it appears
  10    that quite a lot of non-zero-otag lines are pushed into ocacheL2.
  11
  12    This program needs to be compiled with -O.
  13 */
  14
  15 #include <assert.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include "../memcheck.h"
  19
  20
  21 double** alloc_square_array ( int nArr )
  22 {
  23   int i;
  24   double** vec;
  25   assert(nArr >= 1);
  26   vec = malloc(nArr * sizeof(double*));
  27   assert(vec);
  28   for (i = 0; i < nArr; i++) {
  29     vec[i] = malloc(nArr * sizeof(double));
  30     assert(vec);
  31   }
  32   return vec;
  33 }
  34
  35 double** do3x3smooth ( double** arr, int nArr )
  36 {
  37   int i, j;
  38   double** out;
  39   assert(nArr >= 3);
  40   out = alloc_square_array(nArr - 2);
  41   assert(out);
  42   for (i = 1; i < nArr-1; i++) {
  43     for (j = 1; j < nArr-1; j++) {
  44       double s =   arr[i-1][j-1] + arr[i-1][j  ] + arr[i-1][j+1]
  45                  + arr[i  ][j-1] + arr[i  ][j  ] + arr[i  ][j+1]
  46                  + arr[i+1][j-1] + arr[i+1][j  ] + arr[i+1][j+1];
  47       out[i-1][j-1] = s / 9.0;
  48     }
  49   }
  50   return out;
  51 }
  52
  53 double sum ( double** arr, int nArr )
  54 {
  55   int i, j;
  56   double s = 0.0;
  57   assert(nArr >= 1);
  58   for (i = 0; i < nArr; i++) {
  59     for (j = 0; j < nArr; j++) {
  60       s += arr[i][j];
  61     }
  62   }
  63   return s;
  64 }
  65
  66 void setup_arr ( /*OUT*/double** arr, int nArr )
  67 {
  68   int i, j;
  69   assert(nArr >= 1);
  70   for (i = 0; i < nArr; i++) {
  71     for (j = 0; j < nArr; j++) {
  72       arr[i][j] = (double)(i * j);
  73       if (i == nArr/2 && j == nArr/2) {
  74          unsigned char* p = (unsigned char*)&arr[i][j];
  75          (void) VALGRIND_MAKE_MEM_UNDEFINED(p, 1);
  76       }
  77     }
  78   }
  79 }
  80
  81 int main ( void )
  82 {
  83   int nArr = 2300;
  84   int ri;
  85   double r, **arr, **arr2, **arr3;
  86   arr = alloc_square_array(nArr);
  87   setup_arr( arr, nArr );
  88   arr2 = do3x3smooth( arr, nArr );
  89   arr3 = do3x3smooth( arr2, nArr-2 );
  90   r = sum( arr3, nArr-4 );
  91   /* Convert answer to int before testing it, so as to
  92      guarantee there's only one conditional branch. */
  93   if (0) fprintf(stderr, "r = %g\n", r );
  94   r /= 10000.0;
  95   ri = (int)r;
  96   if (0) fprintf(stderr, "ri = %d\n", ri);
  97   if (ri == 696565111) {
  98      fprintf(stderr, "Test succeeded.\n");
  99   } else {
 100      fprintf(stderr, "Test FAILED !\n");
 101      assert(0);
 102   }
 103   return 0;
 104 }