Subversion Repositories openrisc_2011-10-31

/* { dg-do run } */

/* Testcase distilled from glibc's nss_parse_service_list in nss/nsswitch.c

   It can't be distilled further.  Fails with `-O2' for i[3456]86.  */

/* this simulates a bounded-pointer type.  */

struct ucharp { unsigned char *v, *l, *h; };

/* this simulates bounded-pointer check prior to pointer dereference.  */

#define AREF(var, idx) ((((((((var).v+(idx)) < (var).l) \

                           || (((var).v+(idx)+1) > (var).h))) \

                          && (__builtin_trap (), 0)), \

                         (var).v)[(idx)])

struct list

{

  struct list *next;

};

struct list *

alloc_list (void)

{

  static struct list l;

  return &l;

}

int one = 1;

void

foo (struct ucharp cp, struct ucharp lp, struct list **nextp)

{

  while (1)

    {

      struct list *list;

      while (AREF (lp, 0) && AREF (cp, AREF (lp, 0)))

        ++lp.v;

      list = alloc_list ();

      while (AREF (cp, AREF (lp, 0)))

        ++lp.v;

      if (AREF (lp, 0) == one)

        do

          ++lp.v;

        while (AREF (lp, 0) && AREF (cp, AREF (lp, 0)));

      /* The above AREF (cp, ...) fails because the pseudo created to

         hold cp.v holds garbage, having never been set.

         The easiest way to see the problem is to compile wiht `-O2 -da'

         then look at *.09.loop.  Search for something like this:

         Hoisted regno 183 r/o from (mem/s:SI (reg:SI 16 argp) 10)

           Replaced reg 91, deleting init_insn (213).

         Now, look for the use of reg 91, which has no set.  */

      *nextp = list;

      nextp = &list->next;

      if (!*lp.v)

        break;

    }

}

extern void exit (int);

int

main (void)

{

  static unsigned char cp0[] = "\0\0\0\0";

  struct ucharp cp = { cp0, cp0, cp0 + sizeof (cp0) };

  static unsigned char lp0[] = "\1\1\0\0";

  struct ucharp lp = { lp0, lp0, lp0 + sizeof (lp0) };

  struct list list;

  struct list *nextp = &list;

  foo (cp, lp, &nextp);

  exit (0);

}