Request for comments: mpi and using multiple compilers

[Eric A. Borisch]

On Mon, Aug 5, 2013 at 6:09 PM, Sean Farley <sean at macports.org> wrote:
>
> eborisch at macports.org writes:
>> I personally swap back and forth between variants of mpich
>> when I'm testing my own MPI code (why, oh why, doesn't clang have
>> OpenMP support yet?)
>
> Because there is almost no benefit for parallel applications? ;-)
> Really, though, if you're in the domain where OpenMP can help
> (computation bound, dense linear algebra) then your time is better spent
> on using CUDA.

Hrmm, not on the Intel PHI we're using. :) (Obviously not MacPorts
related, but I often develop on my mac, so it's nice to be able to
compile & check the OpenMP code.)

> To help get things moving along, I'd suggest we concentrate on the
> +gfortran variant (and therefore having mpich / openmpi use 'PortGroup
> multiplecompilers 1.0'). What would be holding back using the
> multiplecompilers group with active_variants?

I have no qualms moving to the portgroup; any concerns on the list
with adding the portgroup [1] to trunk?

Would you consider modifying it (perhaps it does and I missed it) to
support something like "multiplecompilers.dragonegg = 0" to disable a
family (or particular version) rather than making the variants
explicitly and having them error out in the Portfile?

Thanks,
  Eric

[1] https://bitbucket.org/seanfarley/scienceports/src/2832e9d9716e178f20b5ab0eb563f40d7fcce730/_resources/port1.0/group/multiplecompilers-1.0.tcl?at=default