Basic HTML version of Foils prepared 2 October 1995

Foil 20 Collective Communication Primitives

From New CPS615 Foils-- D 23 September 95 CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Geoffrey C. Fox


1 The example uses three idealized (not present in real message passing system) primitives
2 Message Passing Shift to right MPSHIFT (+1, SOURCE, DEST)
3 Sends 1 word in location SOURCE to processor on the right
4 Receives word in location DEST from the processor on the left
5 SOURCE and DEST are locations -- if set to "DUMMY", then no information is to be sent or received
6 Message Passing Shift to left MPSHIFT (-1, SOURCE, DEST)
7 Sends 1 word in SOURCE to processor on the left
8 Receives word in DEST from processor on the right
9 GLOBALMAX (TEST)
10 takes TEST from all processors
11 forms TESTMAX = maximum value of TEST over all processors
12 replaces TEST by TESTMAX in all processors

in Table To:


© on Tue Oct 7 1997