1  /* Simple check that sibling calls are performed from a
       2     void non-leaf-function taking one int argument calling itself.
       3  
       4     Copyright (C) 2002 Free Software Foundation Inc.
       5     Contributed by Hans-Peter Nilsson  <hp@bitrange.com>  */
       6  
       7  /* { dg-do run } */
       8  /* { dg-options "-O2 -foptimize-sibling-calls" } */
       9  
      10  /* See note in recurser_void() as to why we disable threading.  */
      11  /* { dg-additional-options "-fdisable-tree-thread1" } */
      12  
      13  /* The option -foptimize-sibling-calls is the default, but serves as
      14     marker.  Self-recursion tail calls are optimized for all targets,
      15     regardless of presence of sibcall patterns.  */
      16  
      17  extern void abort (void);
      18  extern void exit (int);
      19  
      20  extern void recurser_void (int);
      21  extern void track (int);
      22  
      23  int main ()
      24  {
      25    recurser_void (0);
      26    exit (0);
      27  }
      28  
      29  void
      30  recurser_void (int n)
      31  {
      32    /* In some architectures like ppc64*, jump threading may thread
      33       paths such that there are two calls into track(), one for
      34       track(0) and one for track(7).  The track(7) call can be
      35       transformed into a jump instead of a call, which means that
      36       different calls into track() may end up with a different
      37       &stackpos.  This is the reason we disable jump threading for this
      38       test.  */
      39    if (n == 0 || n == 7)
      40      track (n);
      41  
      42    if (n == 10)
      43      return;
      44  
      45    recurser_void (n + 1);
      46  }
      47  
      48  void *trackpoint;
      49  
      50  void __attribute__ ((noipa))
      51  track (int n)
      52  {
      53    char stackpos[1];
      54  
      55    if (n == 0)
      56      trackpoint = stackpos;
      57    else if (n != 7 || trackpoint != stackpos)
      58      abort ();
      59  }