gnu/dist/gcc4/gcc/testsuite/gcc.c-torture/execute/loop-ivopts-3.c

   1 /* Test for a bug in 4.1 ivcanon code.  The loop ends up with two IV, both
   2    with a base of &num[1]. In the provess of converting the < condition to =
   3    we calculate (base1 - 1) - base0, which overflows and gives 0xffffffffu
   4    leading to a bogus loop iteration count.  */
   5 #include <stdlib.h>
   6
   7 struct f
   8 {
   9     int initial_offset;
  10     int can_eliminate;
  11     int can_eliminate_prev;
  12 };
  13
  14
  15 struct f num[2] = {{1, 3, 5}, {30, 50, 70}};
  16 int x = 0;
  17
  18 int main()
  19 {
  20     struct f *p;
  21     for (p = num; p < &num[1]; p++)
  22         {
  23             x += p->can_eliminate;
  24         }
  25     if (x != 3)
  26       abort();
  27     exit (0);
  28 }