Parallel Reduction

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jayshenoy

Parallel Reduction

Post by jayshenoy »

I recently learnt that OpenMP doesn't support array reduction (correct me if I'm wrong.). How can I implement segmented scan instead for
the array using OpenMP, I'm sorry I couldn't find much literature on segmented scan.

Thank in advance

MarkB
Posts: 808
Joined: Thu Jan 08, 2009 10:12 am
Location: EPCC, University of Edinburgh

Re: Parallel Reduction

Post by MarkB »

OpenMP only supports array reductions in Fortran.

There is some discussion about segmented scan algorithms here which might help: http://ocw.mit.edu/courses/mathematics/ ... pter_3.pdf

If you have enough segments such that load balancing is not a problem, then using a parallel loop over segments with a suitable schedule clause might work OK.

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