[MPI3 Fortran] What if Fortran is the primary interface?

Torsten Hoefler htor at cs.indiana.edu
Fri Mar 14 19:41:26 CDT 2008


Hi,
> > It appears to me that the current proposal basically intends to pass
> > data thru to the presumably existing C implementation layer. How will
> > this work for an implementation where the Fortran binding is a primary
> > one?
> >
> > I believe that at least NEC has followed this route. I'm adding Hubert
> > Ritzdorf, in case he's accidentally not involved into this discussion
> > yet, to verify NEC's position.
> 
> I thought that NEC provided functions written in C that are callable  
> directly via Fortran.  The code in the C MPI_Send and the "Fortran"  
> MPI_SEND was essentially the same C code -- the point of the design  
> was the avoid a second function call from the Fortran API functions.
It seemed so to me too.

> Do we really need to worry about [real] native Fortran MPI  
> implementations?
I do not think that it would be useful to write a whole MPI library (or
even big parts of it) in Fortran because it seems pretty hard to
interface C-functions. And pretty much all system libraries are written
in C (e.g., sockets). It would probably be possible to provide glue code
(assembler/C) to use those functions from Fortran but certainly not
easy.

My personal opinion is that we should not worry/care about such an
implementation.

Best,
  Torsten

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