Optimal Packed String Matching

Authors Oren Ben-Kiki, Philip Bille, Dany Breslauer, Leszek Gasieniec, Roberto Grossi, Oren Weimann



PDF
Thumbnail PDF

File

LIPIcs.FSTTCS.2011.423.pdf
  • Filesize: 478 kB
  • 10 pages

Document Identifiers

Author Details

Oren Ben-Kiki
Philip Bille
Dany Breslauer
Leszek Gasieniec
Roberto Grossi
Oren Weimann

Cite AsGet BibTex

Oren Ben-Kiki, Philip Bille, Dany Breslauer, Leszek Gasieniec, Roberto Grossi, and Oren Weimann. Optimal Packed String Matching. In IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2011). Leibniz International Proceedings in Informatics (LIPIcs), Volume 13, pp. 423-432, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2011)
https://doi.org/10.4230/LIPIcs.FSTTCS.2011.423

Abstract

In the packed string matching problem, each machine word accomodates alpha characters, thus an n-character text occupies n/alpha memory words. We extend the Crochemore-Perrin constant-space O(n)-time string matching algorithm to run in optimal O(n/alpha) time and even in real-time, achieving a factor alpha speedup over traditional algorithms that examine each character individually. Our solution can be efficiently implemented, unlike prior theoretical packed string matching work. We adapt the standard RAM model and only use its AC0 instructions (i.e. no multiplication) plus two specialized AC0 packed string instructions. The main string-matching instruction is available in commodity processors (i.e. Intel's SSE4.2 and AVX Advanced String Operations); the other maximal-suffix instruction is only required during pattern preprocessing. In the absence of these two specialized instructions, we propose theoretically-efficient emulation using integer multiplication (not AC0) and table lookup.
Keywords
  • String matching
  • bit parallelism
  • real time
  • space efficiency

Metrics

  • Access Statistics
  • Total Accesses (updated on a weekly basis)
    0
    PDF Downloads
Questions / Remarks / Feedback
X

Feedback for Dagstuhl Publishing


Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail