Improved bit-parallel string matching algorithm overcoming computer word size limitation

Abstract

Algorithms that uses bit-wise operations are known as bit-parallel algorithms. Technique of bit-parallelism has been very useful in string matching area since the introduction of the Shift-Or algorithm. In this algorithm, the input pattern length (m) is required to be less than the computer word size (W) to benefit from the full power of bit-parallelism. In the past, BLIM (Bit-parallel length independent matching) has been used to solve this word length problem efficiently. In this study, we propose a method that improves the efficiency of the BLIM algorithm further. This algorithm uses multiple characters to compute the value by which each text window is to be shifted during matching. Experimental results indicate that the proposed algorithm is faster than BLIM algorithm while retaining its main advantage.