[MPI3 Fortran] Deprecate mpif.h?

Bill Long longb at cray.com
Mon Mar 8 10:20:55 CST 2010

Rolf Rabenseifner wrote:
> I want to point here to a technical problem with the nice section
> MPI-2.2 482:39-484:18 "Problems Due to Data Copying and Sequence Association"
> I've done a test with assumed-shape and assumed-size formal
> arguments as buffer and using a strided actual argument when calling the
> routine (e.g. MPI_IRECV).
> With assumed-size, the compiler did call-by-in-and-out-copy,
> with assumed-shape, the compiler did call-by-reference.

Just to avoid possible confusion, the assumed-size case (around since 
f77) is typically done with simple call-by-reference, whereas a case 
with an assumed-shape actual argument causes copy-in/copy-out if the 
associated dummy is not assumed-shape.  Indeed, copy-in does not work 
for an assumed-size actual since you don't know the size.   I realize 
that this was just a wording slip (Rolf clearly knows the right ideas), 
but it was what prompted me to write up the terminology summary 


Bill Long                                           longb at cray.com
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