(j3.2006) (SC22WG5.3513) Not the Dutch National Activity Report.

Toon Moene toon
Thu Feb 7 14:20:05 EST 2008

Unfortunately, I haven't yet heard from Matthijs (he has all the 
contacts with the Dutch Fortran Committee).

In the mean time I'll report some activity of my own.  I see that we 
will (again - rolls eyes) have to vote on co-arrays.  Well, I will 
dutifully cast my vote, but this time I decided to actually *do* 
something about co-arrays, instead of just voting on them.

I submitted the following proposal for a paper at the GCC Summit in June 
this year in Ottawa (http://www.gccsummit.org):

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Towards an implementation of Co-Array Fortran.

There is a good chance that Co-Array Fortran (of which one can
find a description here: ftp://ftp.nag.co.uk/sc22wg5/N1651-N1700/N1677.pdf)
will be included in the Fortran 2008 Standard.

 From the article cited above:
"A Fortran program containing co-arrays is interpreted as if it were
replicated a fixed number of times and all copies were executed
asynchronously. Each copy has its own set of data objects and is
called an image. The array syntax of Fortran is extended with additional
trailing subscripts in square brackets to give a clear and 
straightforward representation of access to data on other images."

I will describe the steps that have to be undertaken to make
GNU Fortran capable of compiling Fortran programs using
co-arrays.  This includes enhancements to the parser, the
intermediate description of programs in the Fortran Front End
and the necessary support of the run-time library.

The request for a Co-Array Fortran implementation in GNU Fortran
is an old one: It is the subject of PR 18918 and dates from
the 10th of December 2004, 4 months before the release
of GCC 4.0, the first with the current GNU Fortran compiler.
Although a full implementation - capable of compiling Fortran
codes for distributed memory systems - is challenging, an
implementation that caters for run-of-the-mill quad-core
shared memory PC's that sell for ~ $ 1000 would immediately
be useful.

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Of course, as yet it's only a proposal - it still has to pass the review 
committee (1 out of 3 papers makes it).

But I can always decide (like I did in 2006) to write the paper anyway, 
regardless of acceptance by the Summit reviewers.

Kind regards, and see you Sunday !

Toon Moene - e-mail: toon at moene.indiv.nluug.nl - phone: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
At home: http://moene.indiv.nluug.nl/~toon/
Progress of GNU Fortran: http://gcc.gnu.org/ml/gcc/2008-01/msg00009.html

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