gnu/dist/gcc4/gcc/testsuite/gcc.c-torture/execute/arith-rand.c

   1 long
   2 simple_rand ()
   3 {
   4   static unsigned long seed = 47114711;
   5   unsigned long this = seed * 1103515245 + 12345;
   6   seed = this;
   7   return this >> 8;
   8 }
   9
  10 unsigned long int
  11 random_bitstring ()
  12 {
  13   unsigned long int x;
  14   int n_bits;
  15   long ran;
  16   int tot_bits = 0;
  17
  18   x = 0;
  19   for (;;)
  20     {
  21       ran = simple_rand ();
  22       n_bits = (ran >> 1) % 16;
  23       tot_bits += n_bits;
  24
  25       if (n_bits == 0)
  26         return x;
  27       else
  28         {
  29           x <<= n_bits;
  30           if (ran & 1)
  31             x |= (1 << n_bits) - 1;
  32
  33           if (tot_bits > 8 * sizeof (long) + 6)
  34             return x;
  35         }
  36     }
  37 }
  38
  39 #define ABS(x) ((x) >= 0 ? (x) : -(x))
  40
  41 main ()
  42 {
  43   long int i;
  44
  45   for (i = 0; i < 1000; i++)
  46     {
  47       unsigned long x, y;
  48       x = random_bitstring ();
  49       y = random_bitstring ();
  50
  51       if (sizeof (int) == sizeof (long))
  52         goto save_time;
  53
  54       { unsigned long xx = x, yy = y, r1, r2;
  55         if (yy == 0) continue;
  56         r1 = xx / yy;
  57         r2 = xx % yy;
  58         if (r2 >= yy || r1 * yy + r2 != xx)
  59           abort ();
  60       }
  61       { signed long xx = x, yy = y, r1, r2;
  62         if ((unsigned long) xx << 1 == 0 && yy == -1)
  63           continue;
  64         r1 = xx / yy;
  65         r2 = xx % yy;
  66         if (ABS (r2) >= (unsigned long) ABS (yy) || (signed long) (r1 * yy + r2) != xx)
  67           abort ();
  68       }
  69     save_time:
  70       { unsigned int xx = x, yy = y, r1, r2;
  71         if (yy == 0) continue;
  72         r1 = xx / yy;
  73         r2 = xx % yy;
  74         if (r2 >= yy || r1 * yy + r2 != xx)
  75           abort ();
  76       }
  77       { signed int xx = x, yy = y, r1, r2;
  78         if ((unsigned int) xx << 1 == 0 && yy == -1)
  79           continue;
  80         r1 = xx / yy;
  81         r2 = xx % yy;
  82         if (ABS (r2) >= (unsigned int) ABS (yy) || (signed int) (r1 * yy + r2) != xx)
  83           abort ();
  84       }
  85       { unsigned short xx = x, yy = y, r1, r2;
  86         if (yy == 0) continue;
  87         r1 = xx / yy;
  88         r2 = xx % yy;
  89         if (r2 >= yy || r1 * yy + r2 != xx)
  90           abort ();
  91       }
  92       { signed short xx = x, yy = y, r1, r2;
  93         r1 = xx / yy;
  94         r2 = xx % yy;
  95         if (ABS (r2) >= (unsigned short) ABS (yy) || (signed short) (r1 * yy + r2) != xx)
  96           abort ();
  97       }
  98       { unsigned char xx = x, yy = y, r1, r2;
  99         if (yy == 0) continue;
 100         r1 = xx / yy;
 101         r2 = xx % yy;
 102         if (r2 >= yy || r1 * yy + r2 != xx)
 103           abort ();
 104       }
 105       { signed char xx = x, yy = y, r1, r2;
 106         r1 = xx / yy;
 107         r2 = xx % yy;
 108         if (ABS (r2) >= (unsigned char) ABS (yy) || (signed char) (r1 * yy + r2) != xx)
 109           abort ();
 110       }
 111     }
 112
 113   exit (0);
 114 }