(j3.2006) (SC22WG5.5930) Comments on some of the comments

Malcolm Cohen malcolm
Thu Aug 10 20:19:13 EDT 2017


John Reid writes:
>An underlying assumption of HPC has always been that the team values on
>the images of a team would differ from image to image.

Sorry, but I cannot agree with this.  Where has coarray TS said anything 
that might imply this?  I see nowhere, and the technical effect of what it 
does state implies the opposite!

It might have been in some people's minds, but it is counter to various 
things I have heard other people involved in HPC say.  Perhaps they were all 
mistaken, but...

Moreover, it would have been very easy (trivial in fact) to make a team 
variable "differ from image to image", BUT THIS WAS NEVER DONE.  According 
to the coarray TS and the draft standard you can assign team variables from 
one image to another AND THIS DOES NOT CHANGE THE VALUE, so it still 
identifies the same team.

Such a fundamental upheaval in the model is simply unacceptable.  Those who 
have already started to implement teams according to the coarray TS, as 
modified by the tweaks we have made later, are going to be very annoyed they 
have to restart their design.

If you are serious, in my opinion this mean you should be voting NO on the 
CD and going back to the beginning.  Oh, and stop calling it Fortran 2015 as 
this is a fundamental change.  Fortran 2017 (assuming we can actually reach 
agreement this year!) is what it should be.

I cannot believe that we are revisiting fundamental design issues years 
after publication of the TS and when we are supposedly so far advanced in 
standardising F2015.

Finally,
>This what the changes aim to ensure.

Right, that you can no longer use GET_TEAM fully is merely collateral 
damage.  Words like "you can not be serious" spring ineluctably to mind.

Yours in despair,
-- 
............................................Malcolm.




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