Jeff,

It seems that there is a spectrum of 4 options:

1. Deprecate mpif.h and MPI's implicit Fortran interfaces. This is NOT removing mpif.h support from the spec or any implementation -- deprecating just states that the standard *MAY* remove them sometime in the future. If we went this route, I'm sure that it would be a LOOOOONG time before mpif.h is removed from the spec because of the millions of lines of existing MPI codes out there that use it.

2. Don't deprecate mpif.h, but do not include any new MPI-3 functionality in it. This is really only a minor distinction from deprecating; it's just a slightly less-strong statement meant to assure Fortran programmers that we are NOT abandoning mpif.h. However, the road to all new MPI-3 functionality is via the proposed MPI-3 explicit bindings (i.e., "use mpi3").

3. Include all new MPI-3 functionality in mpif.h *except* for the "large count" functionality. This allows mpif.h-using applications to get most of the MPI-3 goodness, with the exception that only INTEGER counts will be supported. If your app needs larger counts than that, you must "use mpi3".

4. Include all new MPI-3 functionality in mpif.h, including "large count" functionality.

What is everyone's opinion on which (1-4) the Forum should go with? It seems like the route to go with the C-bindings (and also the general bindings) is not clear yet and this would decide the outcome. Because if we decide to take the "64-bit" (tm) approach and double the number of function symbols, then the issue would be much simpler. However, if we decide to take the int -> MPI_Count approach, then I don't see how we can "extend" F77 in a standard-conforming and portable manner (but I might miss something).

So depending on the outcome, I would vote: - if we choose the extra function symbol for long types: option 4 - if we choose the MPI_Count approach: option 3 All the Best, Torsten -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Postdoctoral Fellow Open Systems Lab | Indiana University 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA Lindley Hall Room 135 | +01 (812) 856-0501