gcc/testsuite/gcc.dg/sibcall-2.c

   1 /* Simple check that sibling calls are performed from a
   2    void non-leaf-function taking no arguments 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 /* The option -foptimize-sibling-calls is the default, but serves as
  11    marker.  Self-recursion tail calls are optimized for all targets,
  12    regardless of presence of sibcall patterns.  */
  13
  14 extern void abort (void);
  15 extern void exit (int);
  16
  17 extern void recurser_void (void);
  18 extern void track (void);
  19
  20 int n = 0;
  21 int main ()
  22 {
  23   recurser_void ();
  24   exit (0);
  25 }
  26
  27 void
  28 recurser_void (void)
  29 {
  30   if (n == 0 || n == 7)
  31     track ();
  32
  33   if (n == 10)
  34     return;
  35   n++;
  36   recurser_void ();
  37 }
  38
  39 void *trackpoint;
  40
  41 void __attribute__ ((noinline))
  42 track ()
  43 {
  44   char stackpos[1];
  45
  46   if (n == 0)
  47     trackpoint = stackpos;
  48   else if (n != 7 || trackpoint != stackpos)
  49     abort ();
  50 }