Issue No. 10 - October (1993 vol. 4)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/71.246079
<p>This paper presents a family of algorithms for producing, from ( upsilon /sub 0/, upsilon/sub 1/, ..., upsilon /sub n-1/), all initial prefixes x/sub i/= upsilon /sub 0/ theta upsilon/sub 1/ theta ... theta upsilon /sub i/ (i=0, 1, ..., n-1) in parallel in interconnectionnetworks such as the omega network and the hypercube, where theta is an associativebinary operator. Each algorithm can be embedded in the switches and interconnections ofthe network, and can be executed in O((log/sub 2/ r+1) log/sub r/ n) time steps providedthat the network connecting n processors is constructed by using an r*r switch, and thatparallelism within as well as among individual switches is exploited. The objective of these algorithms is to attain a communication pattern that fits the topology of the network. One type of network can be made equivalent to, or can be embedded in, another type of network, so a family of algorithms can be derived from one basic algorithm. In the basic algorithm, every processor p/sub i/ upward multicasts upsilon /sub i/ to processors p/sub k/ (k=i+1, i+2, ..., n - 1). En route to p/sub i/, upsilon /sub j/ (j=0, 1, ..., i - 1) are combined in the switches to produce the (i - 1)th initial prefix x/sub i-1/ that is received by p/sub i/, which can then compute the ith initial prefix x/sub i/=x/sub i-1/ theta upsilon /sub i/.</p>
Index Termsparallel prefix algorithms; interconnection networks; omega network; hypercube;associative binary operator; communication pattern; hypercube networks; parallelalgorithms
M. Takesue, "A Family of Parallel Prefix Algorithms Embedded in Networks," in IEEE Transactions on Parallel & Distributed Systems, vol. 4, no. , pp. 1179-1184, 1993.