[Mpi-forum] MPI_Count

Snir, Marc snir at illinois.edu
Mon Jan 25 15:47:21 CST 2010

call it MPI_COUNT and specify it is a 64 bit integer -- if you insist. My argument is that it should have the same size on all implementations -- I care less how you call it.

On Jan 25, 2010, at 3:04 PM, Jeff Squyres wrote:

> On Jan 24, 2010, at 9:21 PM, Snir, Marc wrote:
>> I would suggest to use explicitly 64 bit integers as the type of count in the new functions. I.e., int64_t in C and INTEGER(KIND=8) in Fortran. Both types are part of the (C/Fortran) standard.
> FWIW, I mentioned the above point on the MPI3 Fortran WG mailing list and got this reply:
>> Please do not touch any of the <stdint.h> stuff with a
>> bargepole!  Stick to the basic types and MPI type names.
>> There are many different ways where <stdint.h> integers cause portability,
>> efficiency and other problems.  Inter alia, the current revision of C is
>> thinking of changing them in ways that could be incompatible with old code,
>> and they are semantically incompatible with Fortran and many other languages
>> in several respects.
>> MPI_count gives the opportunity to evade any such chaos, whether introduced
>> by the standard or an implementation.
> -- 
> Jeff Squyres
> jsquyres at cisco.com
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Marc Snir
4323 Siebel Center, 201 N Goodwin, IL 61801
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