[MPI3 Fortran] Specify IN/OUT/INOUT in MPI spec?

Bill Long longb at cray.com
Thu May 28 12:33:43 CDT 2009

Lionel, Steve wrote:
> That's fine - I was just doing this for a formatting example.  I agree that different named constants for KIND values makes sense here.  I'd take a lead from the C binding to see if it had different typedefs for the integer kinds.

I think the C binding could use some improvements first before following 
their lead.  It is pretty out of date.  For example...
> Steve

Nick wrote:
> Please, no!  If we are going to use KIND, let it be done properly.  There
> needs to be a set of KINDs, because you have at least three different uses
> of integers there.
> I would tend to split them into counts (i.e. COUNT), handles (i.e. DATATYPE
> and COMM) and smallish integers (i.e. DEST, TAG and IERROR).  But another
> division might be better.

I agree. The idea of using int for a buffer size is incompatible with 
arrays > 4GB.  It should be size_t instead.  Some sort of rework, along 
the lines Nick suggests, should be done for both the C and Fortran 
bindings.  In the end they should match.


Bill Long                                   longb at cray.com
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