(j3.2006) referencing co-array variable that is an ultimate argument

Malcolm Cohen malcolm
Wed May 23 20:27:17 EDT 2007

Aleksandar Donev said:
> On Tuesday 22 May 2007 17:49, Malcolm Cohen wrote:
> > That could well make coarray dummy arguments nearly completely unusable
> > when the TARGET attribute is not being used.
> We say:
> "While an entity is associated with a dummy argument...action that affects the 
> value of the entity or any subobject of it shall be taken only through the 
> dummy argument unless..."
> I think it is clear that all of this talks about execution on a particular 
> image.


If you wanted the standard to only refer to what happens on a single
image, coarrays should be a supplemental standard, not integrated.

> "While" only makes sense when talking about one image and one 
> execution sequence.

Not so - you've added loads of guff specifying cross-image time

> The value of such entitities can be changed by other 
> images, as we want of course.

No they cannot.  The words say that.

> What is the problem?

(a) contrary to the standard;
(b) destroys optimisation.

........................Malcolm Cohen (malcolm at nag-j.co.jp), Nihon NAG, Tokyo.

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