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

   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 /* 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 (int);
  18 extern void track (int);
  19
  20 int main ()
  21 {
  22   recurser_void (0);
  23   exit (0);
  24 }
  25
  26 void
  27 recurser_void (int n)
  28 {
  29   if (n == 0 || n == 7)
  30     track (n);
  31
  32   if (n == 10)
  33     return;
  34
  35   recurser_void (n + 1);
  36 }
  37
  38 void *trackpoint;
  39
  40 void __attribute__ ((noinline))
  41 track (int n)
  42 {
  43   char stackpos[1];
  44
  45   if (n == 0)
  46     trackpoint = stackpos;
  47   else if (n != 7 || trackpoint != stackpos)
  48     abort ();
  49 }