[Mpi-22] MPI-2.1 ambiguity?

[Jeff Squyres]

On Jul 18, 2008, at 2:21 PM, William Gropp wrote:

>> It might be a whole lot simpler to specifically define which
>> predefined handles need to be available in each language.  The
>> spectrum ranges from "all languages' predefined handles must be
>> available in every language" to "only that language A's predefined
>> handles must be available in language A".  Suggestions?
>
> I'm in favor of explicitly specifying the values and names (because  
> of the need to use alternate names when their might be a conflict,  
> as in the MPI::F_COMPLEX case), and that these have the exact same  
> value as if the handle transfer function was used.

Do we really need to mandate that they have the same value, or just  
exhibit the same behavior?  Specifically does it matter if this code  
hits branch A or B?

     MPI_Fint ftype;
     ftype = MPI_Type_c2f(MPI_INT);
     if (MPI_INT == MPI_Type_f2c(ftype)) {
         //branch A
     } else {
         //branch B
     }

Or is it simpler to say that the return from an operation like the  
above must behave exactly like the original, regardless of value?


-- 
Jeff Squyres
Cisco Systems