[MPI3 Fortran] Straw vote on integers kinds

[Bill Long]

N.M. Maclaren wrote:
> On Sep 14 2009, Bill Long wrote:
>> Craig Rasmussen wrote:
>>>
>>> Please vote for one of the options.  ...
>>
>> I'm not convinced there is much real difference among these options.
> 
> I agree, though for slightly different reasons.
> 
> I think that all four are a mistake, because they are conflating all MPI
> integers into one.  I would use two names, one for integers that may scale
> with memory size and one where that would be overkill.

Note that the wiki page includes a proposed MPI_COUNT_KIND, which I 
think is the integer kind that scales with memory size.  I assumed this 
discussion was for integer arguments other than the ones for which 
kind=MPI_COUNT_KIND is specified.  It would help if that were clarified, 
especially if my assumption is wrong.  I agree with Nick that an 
independent kind constant is needed for the size cases.



>>>    4. Specify a named kind in the Fortran interface (MPI_INT_KIND) but
>>>       allow the vendor a choice as to how to address integer promotion
>>>       if users use default integers in their codes. ...
>>
>> Again, I'm not really seeing the practical difference here.
> 

>Why should it be promotion, anyway?  What if the default integer KIND is
>64-bit and MPI_INT_KIND is 32-bit?

Right. "promotion" is a poor term here. "conversion" would be better.

Cheers,
Bill



-- 
Bill Long                                   longb at cray.com
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