Newsgroups: comp.parallel.mpi
From: salo@mrjones.engr.sgi.com (Eric Salo)
Subject: Re: MPI_PROC_NULL and invalid message tags
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: 3 Mar 1996 00:28:32 GMT
Message-ID: <4hap3g$9t3@murrow.corp.sgi.com>

> My question to the group is:  is the standard ambiguous on this point,
> or is the behavior of MPI-F incorrect?

I would argue that you should not get an illegal tag error if you send
to MPI_PROC_NULL. In our implementation, the destination rank is checked
first for exactly this reason. We even allow an illegal communicator in
this situation, although that's rather strange. But I can see valid
reasons for requiring these other args to be valid, and can't really
comment on what the intended meaning for the standard might have been.
 
Eric Salo         Silicon Graphics Inc.             "Do you know what the
(415)933-2998     2011 N. Shoreline Blvd, 7L-802     last Xon said, just
salo@sgi.com      Mountain View, CA   94043-1389     before he died?"

