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Subject: Re: [OMPI users] bug in mpif90? OMPI_FC envvar does not work with 'use mpi'
From: Dominik Goeddeke (dominik.goeddeke_at_[hidden])
Date: 2013-03-13 07:29:18


perfect, thanks!

On 03/13/2013 12:21 PM, Jeff Squyres (jsquyres) wrote:
> Fair point; the "don't do that" aspect of changing compilers with middleware is exactly the type of information that you want to be able to google for. I've added the following paragraph to the FAQ entry http://www.open-mpi.org/faq/?category=mpi-apps#override-wrappers-after-v1.0:
>
> -----
> Note that changing the underlying compiler may not work at all. For example, C++ and Fortran compilers are notoriously binary incompatible with each other (sometimes even within multiple releases of the same compiler). If you compile/install Open MPI with C++ compiler XYZ and then use the OMPI_CXX environment variable to change the mpicxx wrapper compiler to use the ABC C++ compiler, your application code may not compile and/or link. The traditional method of using multiple different compilers with Open MPI is to install Open MPI multiple times; each installation should be built/installed with a different compiler. This is annoying, but it is beyond the scope of Open MPI to be able to fix.
> -----
>
>
> On Mar 13, 2013, at 5:44 AM, Dominik Goeddeke <dominik.goeddeke_at_[hidden]> wrote:
>
>> Yes, sure. My point is just that "strongly discouraged" (as per the FAQ) is different from "simply will not work at all". I find that a bit confusing, especially since in other areas of the FAQ, explicit workarounds are stated, e.g. on how to build a Makefile rule to extract flags from an mpiwrapper to pass them to the compiler manually (which is in exactly the same way "strongly discouraged". Maybe adding something like "is strongly discouraged and may not even work in certain cases, especially with Fortran" can help.
>>
>> Dominik
>>
>> On 03/13/2013 11:37 AM, Paul Kapinos wrote:
>>> AFAIK the GNU people change the Fotran Module syntax every time they get any chance for doing it :-(
>>>
>>> So openmpi compiled with 4.4.6 (sys-default for RHEL 6.x) definitely does not work with 4.5, 4.6, 4.7 versions of gfortran.
>>>
>>> Intel 'ifort' compiler build modules which are compatible from 11.x through 13.x versions.
>>>
>>> So, the recommended solution is to build an own version of Open MPI with any compiler you use.
>>>
>>> Greetings,
>>> Paul
>>>
>>>
>>> P.S. As Hristo said, changing the Fortran compiler vendor and using the precompiled Fortran header would never work: the syntax of these .mod files is not standatised at all.
>>>
>>> On 03/13/13 11:05, Iliev, Hristo wrote:
>>>> However, it works if for example you configure Open MPI with the system supplied
>>>> version of gfortran and then specify a later gfortran version, e.g.
>>>> OMPI_FC=gfortran-4.7 (unless the module format has changed in the meantime).
>>>
>>>
>>>
>>> _______________________________________________
>>> users mailing list
>>>
>>> users_at_[hidden]
>>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>
>> --
>> Jun.-Prof. Dr. Dominik Göddeke
>> Hardware-orientierte Numerik für große Systeme
>> Institut für Angewandte Mathematik (LS III)
>> Fakultät für Mathematik, Technische Universität Dortmund
>>
>> http://www.mathematik.tu-dortmund.de/~goeddeke
>>
>> Tel. +49-(0)231-755-7218 Fax +49-(0)231-755-5933
>>
>>
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>

-- 
Jun.-Prof. Dr. Dominik Göddeke
Hardware-orientierte Numerik für große Systeme
Institut für Angewandte Mathematik (LS III)
Fakultät für Mathematik, Technische Universität Dortmund
http://www.mathematik.tu-dortmund.de/~goeddeke
Tel. +49-(0)231-755-7218  Fax +49-(0)231-755-5933