gcc/testsuite/gcc.dg/sibcall-3.c

   1 /* Simple check that sibling calls are performed from a
   2    void non-leaf-function taking one int argument calling a function which
   3    is about the same as itself.
   4
   5    Copyright (C) 2002 Free Software Foundation Inc.
   6    Contributed by Hans-Peter Nilsson  <hp@bitrange.com>  */
   7
   8 /* { dg-do run { xfail arc-*-* avr-*-* cris-*-* crisv32-*-* h8300-*-* hppa*64*-*-* m32r-*-* m68hc1?-*-* mcore-*-* mn10300-*-* xstormy16-*-* v850*-*-* vax-*-* xtensa-*-* } } */
   9 /* -mlongcall disables sibcall patterns.  */
  10 /* { dg-skip-if "" { powerpc*-*-* } { "-mlongcall" } { "" } } */
  11 /* { dg-options "-O2 -foptimize-sibling-calls" } */
  12
  13 /* The option -foptimize-sibling-calls is the default, but serves as
  14    marker.  This test is xfailed on targets without sibcall patterns
  15    (except targets where the test does not work due to the return address
  16    not saved on the regular stack).  */
  17
  18 extern void abort (void);
  19 extern void exit (int);
  20
  21 /* Sibcalls are not supported in MIPS16 mode, which has direct calls but
  22    not direct jumps.  */
  23 #ifdef __mips
  24 #define ATTR __attribute__((nomips16))
  25 #else
  26 #define ATTR
  27 #endif
  28
  29 static ATTR void recurser_void1 (int);
  30 static ATTR void recurser_void2 (int);
  31 extern void track (int);
  32
  33 int main ()
  34 {
  35   recurser_void1 (0);
  36   exit (0);
  37 }
  38
  39 /* The functions should get the same stack-frame, and best way to make it
  40    reasonably sure is to make them have the same contents (regarding the
  41    n tests).  */
  42
  43 static void __attribute__((noinline)) ATTR
  44 recurser_void1 (int n)
  45 {
  46   if (n == 0 || n == 7 || n == 8)
  47     track (n);
  48
  49   if (n == 10)
  50     return;
  51
  52   recurser_void2 (n + 1);
  53 }
  54
  55 static void __attribute__((noinline)) ATTR
  56 recurser_void2 (int n)
  57 {
  58   if (n == 0 || n == 7 || n == 8)
  59     track (n);
  60
  61   if (n == 10)
  62     return;
  63
  64   recurser_void1 (n + 1);
  65 }
  66
  67 void *trackpoint;
  68
  69 void
  70 track (int n)
  71 {
  72   char stackpos[1];
  73
  74   if (n == 0)
  75     trackpoint = stackpos;
  76   else if ((n != 7 && n != 8) || trackpoint != stackpos)
  77     abort ();
  78 }