0000000000073184

AUTHOR

Tuan Tu Tran

Bit-Parallel Approximate Pattern Matching on the Xeon Phi Coprocessor

Bit-parallel pattern matching encodes calculated values in bit arrays. This approach gains its efficiency by performing multiple updates within a machine word. An important parameter is therefore the machine word size (e.g. 32 or 64 bits). With the increasing length of vector registers, the efficient mapping of bit-parallel pattern matching algorithms onto modern high performance computing architectures is becoming increasingly important. In this paper, we investigate an efficient implementation of the Wu-Manber approximate pattern matching algorithm on the Intel Xeon Phi coprocessor. This architecture features a 512-bit long vector processing unit (VPU) as well as a large number of process…

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CUDA-enabled hierarchical ward clustering of protein structures based on the nearest neighbour chain algorithm

Clustering of molecular systems according to their three-dimensional structure is an important step in many bioinformatics workflows. In applications such as docking or structure prediction, many algorithms initially generate large numbers of candidate poses (or decoys), which are then clustered to allow for subsequent computationally expensive evaluations of reasonable representatives. Since the number of such candidates can easily range from thousands to millions, performing the clustering on standard central processing units (CPUs) is highly time consuming. In this paper, we analyse and evaluate different approaches to parallelize the nearest neighbour chain algorithm to perform hierarc…

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Bit-parallel approximate pattern matching: Kepler GPU versus Xeon Phi

Advanced SIMD features on GPUs and Xeon Phis promote efficient long pattern search.A tiled approach to accelerating the Wu-Manber algorithm on GPUs has been proposed.Both the GPU and Xeon Phi yield two orders-of-magnitude speedup over one CPU core.The GPU-based version with tiling runs up to 2.9 × faster than the Xeon Phi version. Approximate pattern matching (APM) targets to find the occurrences of a pattern inside a subject text allowing a limited number of errors. It has been widely used in many application areas such as bioinformatics and information retrieval. Bit-parallel APM takes advantage of the intrinsic parallelism of bitwise operations inside a machine word. This approach typica…

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SWAPHI-LS: Smith-Waterman Algorithm on Xeon Phi coprocessors for Long DNA Sequences

As an optimal method for sequence alignment, the Smith-Waterman (SW) algorithm is widely used. Unfortunately, this algorithm is computationally demanding, especially for long sequences. This has motivated the investigation of its acceleration on a variety of high-performance computing platforms. However, most work in the literature is only suitable for short sequences. In this paper, we present SWAPHI-LS, the first parallel SW algorithm exploiting emerging Xeon Phi coprocessors to accelerate the alignment of long DNA sequences. In SWAPHI-LS, we have investigated three parallelization approaches (naive, tiled, and distributed) in order to deeply explore the inherent parallelism within Xeon P…

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Perfect Hashing Structures for Parallel Similarity Searches

International audience; Seed-based heuristics have proved to be efficient for studying similarity between genetic databases with billions of base pairs. This paper focuses on algorithms and data structures for the filtering phase in seed-based heuristics, with an emphasis on efficient parallel GPU/manycores implementa- tion. We propose a 2-stage index structure which is based on neighborhood indexing and perfect hashing techniques. This structure performs a filtering phase over the neighborhood regions around the seeds in constant time and avoid as much as possible random memory accesses and branch divergences. Moreover, it fits particularly well on parallel SIMD processors, because it requ…

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