Newsgroups: comp.parallel.mpi
From: Jim Tuccillo <jjt@radia1.com>
Subject: Re: reduction workspace
Organization: http://www.supernews.com, The World's Usenet: Discussions Start Here
Date: Tue, 21 Jul 1998 07:30:55 -0400
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Message-ID: <35B47BEF.41C6@radia1.com>

If you are using an SP, you will get the right answer. I cant speak for
all of the different systems you are likely to run your code on.

Eric Salo wrote:
> 
> > The MPI standard would lead you to the conclusion that you must supply
> > different arguments for the send and receive buffers. This doesnt mean
> > that it wont work on some systems if you supply the same argument. The
> > prudent choice is to supply different arguments.
> 
> More to the point, Richard: If you try passing in the same array twice
> like this on your Origin array (with our MPI implementation) you *will*
> get the wrong answers.
> 
> --
> Eric Salo      Silicon Graphics      salo@sgi.com