(j3.2006) (SC22WG5.3998) [ukfortran] New summary of coarrays

[Malcolm Cohen]

Hi Bill and Craig,

Craig Dedo, and then Bill Long, wrote to J3 replying to a WG5 message...

Once again I reiterate my "watch what you are replying to" : J3 list 
readers please use "Reply All" or manually reinsert the WG5 list when 
replying to a WG5 message.

I am copying this to WG5 just so I can stick my oar in on the substance.

Craig Dedo wrote replying to Nick (I think):
> Everyone:
> 	I believe that a better wording for the last sentence would be:
>
> 	The exact details are left processor dependent.  Therefore,
> programmers should read their processor documentation before using atomic
> subroutines.
>
> 	I believe that "processor documentation" is the recommended term.
> Also, breaking it up into two sentences makes it read better.
>   

And Bill Long replied:
> Both versions presume something that seems very unlikely - that vendors
> discuss such implementation and performance details in their
> documentation. I think the whole addition should be dropped. At best it
> is confusing to an ordinary user; at worst is encourages vendors to not
> bother doing a good job.
>   
No, as I understand it existing hardware and physical constraints 
encourages some vendors not to have global consistency; *and* we allow 
them not to have global consistency.

As for "confusing to an ordinary user", not nearly as confusing as 
getting wildly different answers or program hangs/crashes from the same 
data on the same machine on a Thursday.

Cheers,
-- 
..........................Malcolm Cohen, Nihon NAG, Tokyo.