Unstructured Tree Search on SIMD Parallel Computers

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


In this paper, we present new methods for load balancing of unstructured tree computations on large-scale SIMD machines, and analyze the scalability of these and other existing schemes. An efficient formulation of tree search on an SIMD machine consists of two major components: a triggering mechanism, which determines when the search space redistribution must occur to balance the search space over processors, and a scheme to redistribute the search space. We have devised a new redistribution mechanism and a new triggering mechanism. Either of these can be used in conjunction with triggering and redistribution mechanisms developed by other researchers. We analyze the scalability of these mechanisms, and verify the results experimentally. The analysis and experiments show that our new load-balancing methods are highly scalable on SIMD architectures. Their scalability is shown to be no worse than that of the best load-balancing schemes on MIMD architectures. We verify our theoretical results by implementing the 15-puzzle problem on a CM-2 SIMD parallel computer.

Original languageEnglish (US)
Pages (from-to)1057-1072
Number of pages16
JournalIEEE Transactions on Parallel and Distributed Systems
Issue number10
StatePublished - Oct 1994

Bibliographical note

Funding Information:
Manuscript received April 22, 1993; revised October 27, 1993, and November 2, 1993. This work was supported by IST/SDIO through the Army Research Office under Grant 28408-MA-SDI, and by the Army High Per- formance Computing . -Research Center at the University of Minnesota.


  • Artificial intelligence
  • computing
  • heuristic search
  • load balancing
  • parallel
  • unstructured computations


Dive into the research topics of 'Unstructured Tree Search on SIMD Parallel Computers'. Together they form a unique fingerprint.

Cite this