Performance analysis of the Kahan-enhanced scalar product on current multi-core and many-core processors

Hofmann J, Fey D, Riedmann M, Eitzinger J, Hager G, Wellein G (2017)

Publication Status: Published

Publication Type: Journal article

Publication year: 2017

Journal

Concurrency and Computation-Practice & Experience Wiley-Blackwell

Publisher: WILEY

Book Volume: 29

Journal Issue: 9

DOI: 10.1002/cpe.3921

Abstract

We investigate the performance characteristics of a numerically enhanced scalar product (dot) kernel loop that uses the Kahan algorithm to compensate for numerical errors, and describe efficient single instruction multiple data-vectorized implementations on recent multi-core and many-core processors. Using low-level instruction analysis and the execution-cache-memory performance model, we pinpoint the relevant performance bottlenecks for single-core and thread-parallel execution and predict performance and saturation behavior. We show that the Kahan-enhanced scalar product comes at almost no additional cost compared with the naive (non-Kahan) scalar product if appropriate low-level optimizations, notably single instruction multiple data vectorization and unrolling, are applied. The execution-cache-memory model is extended appropriately to accommodate not only modern Intel multicore chips but also the Intel Xeon Phi Knights Corner' coprocessor and an IBM POWER8 CPU. This allows us to discuss the impact of processor features on the performance across four modern architectures that are relevant for high performance computing. Copyright (c) 2016 John Wiley & Sons, Ltd.

Authors with CRIS profile

Johannes Hofmann Lehrstuhl für Informatik 3 (Rechnerarchitektur) Dietmar Fey Lehrstuhl für Informatik 3 (Rechnerarchitektur) Jan Eitzinger Regionales Rechenzentrum Erlangen (RRZE) Georg Hager Regionales Rechenzentrum Erlangen (RRZE) Gerhard Wellein Professur für Höchstleistungsrechnen

Involved external institutions

AREVA GmbH DE Germany (DE)

How to cite

APA:

Hofmann, J., Fey, D., Riedmann, M., Eitzinger, J., Hager, G., & Wellein, G. (2017). Performance analysis of the Kahan-enhanced scalar product on current multi-core and many-core processors. Concurrency and Computation-Practice & Experience, 29(9). https://doi.org/10.1002/cpe.3921

MLA:

Hofmann, Johannes, et al. "Performance analysis of the Kahan-enhanced scalar product on current multi-core and many-core processors." Concurrency and Computation-Practice & Experience 29.9 (2017).

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