Dear all,

I am putting together a lecture on collective communication and was perusing the MPICH 3.0.3 source code when I noticed that the only references for the long-message implementations of Reduce and Broadcast seem to be "Rabenseifer's algorithm" for Reduce, with a pointer to the following webpage and corresponding 1997 publication:
https://fs.hlrs.de/projects/par/mpi//myreduce.html

This seems to be a bit strange to me, since this is essentially the Scatter composed with Allgather approach to Broadcast implemented in reverse, which was proposed by Fox, Furmanski, and Walker nearly a decade earlier in "Optimal matrix algorithms on homogeneous hypercube" (see Figs. 1 and 2, where the term "expand" is used instead of the modern "Allgather"):
http://dl.acm.org/citation.cfm?id=63125

It would seem to me that, if the source code is to include academic references, it would make sense to also cite this (much earlier) paper.

Best Regards,
Jack Poulson