Re: [PATCH] New tests for sibling call optimisation

[Andreas Bauer <baueran at in dot tum dot de>]

> I'd much rather you tested this in some machine independant way,
> so that all that is needed for new architectures is to add them
> to the target list.
> 
> Hint: use __builtin_return_address(0).

I did not know about the function before.  But, here is an updated
version of the test.  Hope it can be used by people and be applied
now.

> > 	gcc.dg/sibcall-7: New test for indirect sibcalls with
> > 	attribute `noreturn'.
> 
> This is pointless.  The restriction is partly due to a 
> representation problem in the compiler.  The only thing
> that we ought to be verifying is that we don't ICE and
> don't generate incorrect code.

OK, will skip the test then.  Personally, I found it useful while
extending the sibcall optimisation on x86 platforms, but I respect
your intention to not test a compiler shortcoming; we rather test
compiler features.

Thanks for feedback.

Looking forward to further comments,
Andi.

2002-11-04  Andreas Bauer  <baueran@in.tum.de>

	* gcc.dg/sibcall-6: New test for indirect sibcalls.

--- /dev/null   Sun Jul 14 11:06:13 2002
+++ sibcall-6.c Tue Nov  5 11:03:03 2002
@@ -0,0 +1,42 @@
+/* A simple check to see whether indirect calls are
+   being sibcall optimized on targets that do support
+   this notion, i.e. have the according call patterns
+   in place.
+
+   Copyright (C) 2002 Free Software Foundation Inc.
+   Contributed by Andreas Bauer <baueran@in.tum.de>  */
+
+/* { dg-do run { target i?86-*-* x86_64-*-*} } */
+/* { dg-options "-O2 -foptimize-sibling-calls" } */
+
+int foo (int);
+int bar (int);
+
+int (*ptr) (int);
+int *f_addr;
+
+int
+main ()
+{
+  ptr = bar;
+  foo (7);
+  exit (0);
+}
+
+int
+bar (b)
+     int b;
+{
+  if (f_addr == (int*) __builtin_return_address (0))
+    return b;
+  else
+    abort ();
+}
+
+int
+foo (f)
+     int f;
+{
+  f_addr = (int*) __builtin_return_address (0);
+  return (*ptr)(f);
+}