[gmx-developers] Fix for 2 small problems in the cmake for gmx 4.5.5

[Christoph Junghans]

Am 1. März 2012 13:45 schrieb Szilárd Páll <szilard.pall at cbr.su.se>:
> On Thu, Mar 1, 2012 at 9:23 PM, Ake Sandgren <ake.sandgren at hpc2n.umu.se> wrote:
>> On Thu, 2012-03-01 at 18:17 +0100, Szilárd Páll wrote:
>>> Hi,
>>>
>>> Regarding the linking fix, I think we do not always need Fortran,
>>> Gromacs compiles just fine without a Fortran compiler on X86_64. On
>>> what platform/compiler did you have linking issues? I suspect that the
>>> fix might not work in case if there is no Fortran compiler available.
>>
>> Ubuntu Linux using intel compiler.
>> As soon as there is a fortran source file built and then included in the
>> gmxlib you would most likely need it to build the shared lib with the
>> fortran compiler instead of the C compiler. It's far more easy to do it
>> that way then figuring out what the fortran runtime lib might be for
>> what ever fortran compiler have been used and then explicitly add that
>> at shared lib creation time.
>>
>> So whenever the fortran kernels are used for whatever reason...
>>
>> I'll see if i can come up with a better fix...
>
> Right, but as far as I know we only have Fortran kernels for IBM BG
> and I don't know of any other Fortran code. However, someone else
> shoud pitch in here because I might as well be wrong. Devs, anyone?
There are fortran kernels, but they are overwritten by sse, altivec,
bluegene or any other non-generic kernel. That means even if you
compile them in on x86_64 they will never be used.

When using cmake one can only enable one acceleration method. The
automatic default will usually lead to sse acceleration.

We benchmarked the fortran(!=power6) vs. the c kernels on Power6 using
IBM's xl compilers two years ago, but the difference was small.

> On the other hand, I myself have compiled with Intel Compiler on
> Ubuntu and not only and never had problems. Are you using some
> external libraries except FFTW (BLAS, LAPACK)?
>
>>> Could you please submit the patches separately to gerrit.gromacs.org?
>>
>> I'll try to remember that tomorrow.
>
> Thanks! Feel free to just push patches to gerrit whenever you find something!
>
> Here's the guide with the few lines of command you'll need to set up
> your git for gerrit: http://www.gromacs.org/Developer_Zone/Git/Gerrit
>
>> --
>> gmx-developers mailing list
>> gmx-developers at gromacs.org
>> http://lists.gromacs.org/mailman/listinfo/gmx-developers
>> Please don't post (un)subscribe requests to the list. Use the
>> www interface or send it to gmx-developers-request at gromacs.org.
> --
> gmx-developers mailing list
> gmx-developers at gromacs.org
> http://lists.gromacs.org/mailman/listinfo/gmx-developers
> Please don't post (un)subscribe requests to the list. Use the
> www interface or send it to gmx-developers-request at gromacs.org.



-- 
Christoph Junghans
Web: http://www.compphys.de