[MPI3 Fortran] Argument data sizes

[Iain Bason]

On Sep 18, 2008, at 9:50 AM, Jeff Squyres wrote:

> On Sep 18, 2008, at 9:36 AM, Iain Bason wrote:
>
>>> So it isn't that we need the count to be able to convey a huge  
>>> number, it's that the absence of an interface that accepts an 8  
>>> byte count makes it more difficult to write portable programs.
>
> Yes, I understand that, but if MPI itself doesn't accept counts (and  
> other parameter values) larger than what can be represented by a C  
> int, what does allowing an INTEGER*8 in the MPI Fortran interface  
> mean?
>
> If it means that all MPI implementations now have to accept 8-byte  
> counts (etc.), there might be some resistance from the rest of the  
> Forum because it is a potentially large implementation change  
> (internal data structures have to change, wire protocols have to  
> change, which can lead to backwards compatibility issues, etc.).

Is there some reason an implementation couldn't issue a runtime "value  
out of range" error message?

Iain