gcc/testsuite/gcc.dg/20020310-1.c

   1 /* PR optimization/5844
   2    This testcase was miscompiled because of an rtx sharing bug.  */
   3 /* { dg-do run } */
   4 /* { dg-options "-O2" } */
   5 /* { dg-options "-O2 -mtune=i586" { target i?86-*-* } } */
   6 /* { dg-skip-if "" { i?86-*-* } { "-m64" } { "" } } */
   7
   8 struct A
   9 {
  10   struct A *a;
  11   int b;
  12 };
  13
  14 struct B
  15 {
  16   struct A *c;
  17   unsigned int d;
  18 };
  19
  20 struct A p = { &p, -1 };
  21 struct B q = { &p, 0 };
  22
  23 extern void abort (void);
  24 extern void exit (int);
  25
  26 struct B *
  27 foo (void)
  28 {
  29   return &q;
  30 }
  31
  32 void
  33 bar (void)
  34 {
  35   struct B *e = foo ();
  36   struct A *f = e->c;
  37   int g = f->b;
  38
  39   if (++g == 0)
  40     {
  41       e->d++;
  42       e->c = f->a;
  43     }
  44
  45   f->b = g;
  46 }
  47
  48 int
  49 main ()
  50 {
  51   bar ();
  52   if (p.b != 0 || q.d != 1 || q.c != &p)
  53     abort ();
  54   exit (0);
  55 }