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From: Luis Kornblueh (luis.kornblueh_at_[hidden])
Date: 2007-06-14 02:56:58


If it is such a general bug in the PGI compiler it might be worthwhile
to get it PGI fixed fast and distribute that to the users affected.
Usually they are pretty responsive.

> On Jun 13, 2007, at 8:47 PM, Julian Cummings wrote:
>
> > I did some quick tests with my little hello example that indicate that
> > the application code only needs to be *linked* with -fpic, not
> > compiled
> > with it. The -fpic flag on the mpicxx link line points the linker
> > to a
> > PGI "libso" subdirectory that contains dynamic versions of the
> > compiler
> > libraries. In this case, probably libC.so is most important. Anyway,
> > at least you do not have to potentially degrade the performance of the
> > application code by compiling all of it with -fpic. I would recommend
> > that the OpenMPI configuration be modified to insert this flag (or
> > some
> > equivalent) as an LCXXFLAGS or even an LDFLAGS component in the
> > compiler
> > driver scripts whenever PGI is used.
>
> We've had debates about this internally. There was pushabck from
> some of the developers that we don't want to handle every single
> compiler bug that's out there (there are many). It can be a never-
> ending battle. This is a big enough compiler bug, however (it spans
> the 6.2 and 7.0 PGI series) that if someone contributes a patch, we
> might be able to make a big enough case to fix it. The functionality
> I'd like to see in such a patch is:
>
> - in the C++ section of configure, try to compile and run a simple C+
> + (non-MPI) program
> - if it works, fine
> - if it doesn't work, try again but link it with -fpic
> - if that works, then add -fpic to the C++ compiler wrapper flags
>
> All with appropriate comments describing why this check is there (so
> that someone doesn't look at it in 6 months and wonder why the heck
> we're checking for that).
>
> FWIW, you can easily modify the wrapper scripts to automatically put
> this flag in after Open MPI is installed (see http://www.open-mpi.org/
> faq/?category=mpi-apps#override-wrappers-after-v1.0).
>
> --
> Jeff Squyres
> Cisco Systems
>
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 Luis Kornblueh                           Tel. : +49-40-41173289
 Max-Planck-Institute for Meteorology     Fax. : +49-40-41173298
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 D-20146 Hamburg                   Email: luis.kornblueh_at_[hidden]
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