[Mpi-21] MPI-2.1: Fortran 90 bindings
luis.kornblueh at [hidden]
Thu Mar 6 01:51:19 CST 2008
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
> - ...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.
> Jeff Squyres
> Cisco Systems
> mpi-21 mailing list
Luis Kornblueh Tel. : +49-40-41173289
Max-Planck-Institute for Meteorology Fax. : +49-40-41173298
D-20146 Hamburg Email: luis.kornblueh_at_[hidden]
Federal Republic of Germany
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