gcc/testsuite/gcc.dg/torture/pta-ptrarith-3.c

   1 /* { dg-do run } */
   2 /* { dg-options "-fdump-tree-alias" } */
   3 /* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */
   4
   5 extern void abort (void);
   6 struct X {
   7   int *p;
   8   int *q;
   9   int *r;
  10 };
  11 int __attribute__((noinline))
  12 foo(int i, int j, int k, int off)
  13 {
  14   struct X x;
  15   int **p, *q;
  16   x.p = &i;
  17   x.q = &j;
  18   x.r = &k;
  19   p = &x.q;
  20   p += off;
  21   /* *p points to { i, j, k } */
  22   q = *p;
  23   return *q;
  24 }
  25 int main()
  26 {
  27   if (foo(1, 2, 3, -1) != 1)
  28     abort ();
  29   if (foo(1, 2, 3, 0) != 2)
  30     abort ();
  31   if (foo(1, 2, 3, 1) != 3)
  32     abort ();
  33   return 0;
  34 }
  35
  36 /* { dg-final { scan-tree-dump "q_., points-to vars: { i j k }" "alias" } } */
  37 /* { dg-final { cleanup-tree-dump "alias" } } */