[rs6000] Fix compare debug failure on AIX

[Alan Modra]

On Fri, May 01, 2015 at 09:48:51AM -0400, David Edelsohn wrote:
> On Thu, Apr 30, 2015 at 7:28 AM, Eric Botcazou <ebotcazou@adacore.com> wrote:
> >> We might want to check if doing -Og and not just -O0.
> >
> > You're right, thanks, amended patch attached, same ChangeLog.
> 
> Why should GCC unnecessarily create stack frames to avoid
> compare-debug testcase failures?

More to the point, do you need a frame on AIX when debugging?  If yes
then the correct change is to replace

  else if (TARGET_XCOFF && write_symbols != NO_DEBUG)
    info_ptr->push_p = 1;

with

  else if (TARGET_XCOFF)
    info_ptr->push_p = 1;

If no, then the correct change is to delete those lines from
rs6000_stack_info, and fix the comment.

https://gcc.gnu.org/ml/gcc-patches/2003-03/msg01693.html 

-- 
Alan Modra
Australia Development Lab, IBM