[Gomp-discuss] Re: OpenMP, HPC, and the future of GCC

[Steven Bosscher]

> I think the question should be reversed.  Is HPC comunity 
> interested in supporting GNU? 

Financially, no :-)  CJB and Toon tried that once during a BOF for g77,
but the bigger part of the HPC community is in academia, and they're
just lousy funders. 

Manpower, yes.  Absolutely.  Are people interested in OpenMP for GCC?
Just count the number of questions about OpenMP on the mailing list over
the past, say, two years.  And whaddayaknow, some of them would also
like to help develop it. 

>   I don't think anyone working on GCC would not like it 
> to be usefull for more people than it is now and generate 
> better code. To make this happen, someone must realize it. 
> GNU can't do it, someone who actually needs the feature 
> has to make this happen. 

Which is why the "OpenMP for GCC" (Gomp) project now exists. 

> > willing to put in the work if there is reasonable expectation 
> > that the gcc "core" will accept it. But if HPC is going to be 
> >  dismissed automatically, I 
> 
> This is problematic.  Since GCC maintainers can not implement 
> all the HPC support themselves, they can not give in advance 
> an promise that they will accept the code. 

Of course.  But isn't it reasonable to ask if there would be at least a
serious review of the *technical* merits of the concept before a group
of volunteers starts hacking on implementing it? 

>From Per's mail this (European) morning, you'd say he's opposed to
OpenMP just because it stinks from a language design POV.  Fine, OK,
sure, its not Java :-) 

But if that is how the majority of the GCC developer community feels
about OpenMP, then why would anyone spend time on developing the idea? 
I know that I'd rather spend a few hours doing some contract research to
fund my new vendor compiler if nobody will ever accept my patches for
GCC. 

> I personally would like to see GCC usefull for numeric computing 
> too, so I would like to help with the project if it is created 
> as my time allows. 

There's a GOMP project: http://savannah.nongnu.org/projects/gomp. 
Active participants are (among others) Diego Novillo, Sebastian Pop,
Scott Robert Ladd, Lars Segelund, Biagio Lucini and myself.  Or: GNU
C/C++ hackers, GNU Fortran hackers, and numerical professionals.  Anyone
is welcome to join of course. 

We've put the project on a separate mailing list to see how this idea
would evolve, but obviously now that it's getting more serious, we could
(and should IMO) move some discussions to this mailing list. 

>  Every new feature 
> needs to be implemented first and then it needs to be judged 
> on how it works, how maintainable the code is before it can be 
> accepted for mainline GCC. 

Right.  Those are the technical merits of the implementation.  But if
whatever is implemented is already rejected, then there's no point. 

Greetz 
Steven