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

[Jan Hubicka]

> > 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? 

It looks like everyone who wants to start someting bigger on GCC has
this problem.  Except for discussing it on the official mailing lists,
there is no other way to get kind of "approval" on the design of future
change. 

I am personally trying to split every plan into several incremental
steps usefull at their own and push them into mainline so I don't spend
too much time on developing something totaly bogus.  This probably does
not work for everything.  AST branch is good example of this.  Once
branch got past early design problems, many GCC developers examined it
and the overall design seems to be quite clear now.  I guess the same
thing would happen if you get the OpenMP implementation past the early
stages.

> 
> >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. 

Because it is the only standard in the area?  I must say I don't like
the way pragmas are insterted into C as well, but still I think GCC
should adopt it.  I don't like many C++ features either and don't object
against them being integrated in GCC.
After all the parser part of about the easiest part of the project and
less of infrastructure can be independent on this.
> 
> > 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. 

Yes, I was looking at it already.
> 
> 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. 

I think with some good will, it will be sorted out on the way as more
specific issues appear. 

Honza
> 
> Greetz 
> Steven 
>