Re: Patch to xfail g++.dg/tree-prof/indir-call-prof.C on IA64

[Steve Ellcey <sje at cup dot hp dot com>]

> Hi,
> the basic algorithm does not care at all what actually is in the virtual
> tables, because the instrumentation is done at callee site, rather than
> caller.  I guess the problem is that the code simply does not recognize
> call via IA64 vtable as candidate for devirtualization that should be
> tirival to fix.  How does the GIMPLE representation differ here?
> 
> Honza

I am not completely sure what gimple you want to see.  It does look like
IA64 is doing the instrumentation at the callee site.  So if I look at
the call site without any profiling, it looks like IA64 has a bunch of
casts that the devirtualization code may not be expecting:

On IA64 Linux I see:

int main() ()
{
  struct B b;

<bb 2>:
  b.D.2297._vptr.A = &_ZTV1B[2];
  OBJ_TYPE_REF((int (*__vtbl_ptr_type) (void)) &_ZTV1B[2];&b.D.2297->0) (&b.D.22
97);
  return 0;

}



And on x86_64 I see:

int main() ()
{
  struct B b;

<bb 2>:
  b.D.2465._vptr.A = &_ZTV1B[2];
  OBJ_TYPE_REF(_ZTV1B[2];&b.D.2465->0) (&b.D.2465);
  return 0;

}