Coarray article for the upcoming GCC Summit.

[John Reid]

Toon Moene wrote:
> Attached you'll find the draft of my paper on coarray Fortran in GCC for
> the upcoming GCC Summit (see http://www.gccsummit.org).
> 
> It has become a somewhat difficult balance between precision (on the exact
> places and code that have to change in the Fortran front end and run time
> library) and sufficient abstraction to keep the paper within length and
> readable.
> 
> John, it might help the clarity of the paper if I can simply quote paragraph
> 2 of N1724 in full (about the distribution of a coarray over images) -
> do you mind if I do so ?

No. Use N1724 in any way you like.

> A question to my colleagues on J3:  Why exactly is it impossible to write
> the central line of the coarray example in my paper as:
> 
>       p[i] = p
> 
> I don't see how this could be ambiguous ...

I think we could allow this, but "p(:,:)[i] =" reminds the reader that this is
an array assignment and that no allocation on the remote image can occur.

> I would appreciate everyones' comments and suggestions for improvement.

In struct at the top of the second column of page 3, you could discard the
arrays colower and coupper. You have the rank and corank and the total
of the two is limited to 15, so the cobounds could be in the same arrays as
the bounds.

Typo 'an' in line 4 of 5.2.2.
> 
> Please use "Reply All" when you reply, so that it will also go to the 
> GNU Fortran mailing list, as I can't receive outside mail at 
> Meteo France, where I will reside until Friday 25th of April.

Done.

Best wishes,

John.