* Jeff Squyres <jsquyres_at_[hidden]> [2008-03-03 12:08:47]:

...

I think the proposal has merit but we need to be specific that only data representation conversion for data transfer routines is involved in the meaning of "heterogeneous".

Narrowing the scope to "whether translation functionality is required" is good. But note that whether the translation functionality is used may be specific to a given (communicator,peer,datatype) tuple.

You're right that this depends on the communicator and on the peer; It would not be uncommon to have one 'different (memory representation wise)' node in the communicator. This could be a login node, a visualisation node, ... So, from a performance point of view (and also for the mpi implementation internally), it's actually better to record this information for (communicator, source, dest). However, my main reason for this proposal was to enable an application that doesn't care about datatypes (might be more common than you'd think, looking at some of the mpi-subset ideas) to abort execution if it detects that data conversion is needed when communicating to its peers. Greetings, Dries *