Abstract

We consider the problem of merging two sorted sequences on constant degree networks using comparators only. The classical solution to the problem are the networks based on Batcher’s Odd-Even Merge and Bitonic Merge running in log(2n) time. Due to the obvious log n lower bound for the runtime, this is timeoptimal. We present new merging networks that have a novel property of being periodic: for some (small) constant k, each processing unit of the network performs the same operations at steps t and t+k (as long as t+k does not exceed the runtime.) The only operations executed are compare-exchange operations, just like in the case of the Batcher’s networks. The architecture of the networks is very simple, easy to be laid out. The runtimes achieved are c · log n, for a small constant c.

Citations