[Mpi-21] MPI-2.1: Fortran 90 bindings

[Luis Kornblueh]

Well, a remark on that: 

What about providing an ISO_C_BINDING based interface? MPI is not a game
and programmers doing MPI are usually quite good and capable of handling
the basic type checking themselfs ...

> The current MPI-2 F90 bindings are un-implementable because they  
> require almost 7 *million* interface functions: with 15 intrinsic  
> Fortran types, each with 7 possible dimensions, the current F90  
> interface *requires*:
> 
> - 50 MPI functions with one choice buffer: 15 * 7 * 50 = 5,250 functions
> - 25 MPI functions with two choice buffers: (15 * 7 * 25)^2 = 6.8M  
> functions
> - ...and a few hundred more MPI functions with no choice buffers
> 
> This is clearly broken.
> 
> An MPI-2.1-worthy solution could be to add a global statement saying  
> that MPI functions with two choice buffers are explicitly not included  
> in the F90 bindings.  F90 MPI applications can transparently fall back  
> to the F77 bindings (although they won't get the strong type checking,  
> etc.).  This idea therefore fits the requirement of not breaking any  
> existing MPI codes.
> 
> Specifically: if we remove the requirement to provide all MPI  
> functions with two choice buffers, 5,000+ F90 interface functions is  
> [a pain but] implementable.  I doubt that any current MPI  
> implementation provides more than the no-choice-buffers plus one- 
> choice-buffer functions anyway...
> 
> If this seems like a good idea, I can write a proper proposal for it.   
> Comments?
> 
> -- 
> Jeff Squyres
> Cisco Systems
> 
> _______________________________________________
> mpi-21 mailing list
> mpi-21_at_[hidden]
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-21


-- 
                             \\\\\\
                             (-0^0-)
--------------------------oOO--(_)--OOo-----------------------------
 Luis Kornblueh                           Tel. : +49-40-41173289
 Max-Planck-Institute for Meteorology     Fax. : +49-40-41173298
 Bundesstr. 53              
 D-20146 Hamburg                   Email: luis.kornblueh_at_[hidden]
 Federal Republic of Germany