Parallel experiments with RARE-BLAS - LIRMM - Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier Access content directly
Conference Papers Year : 2016

Parallel experiments with RARE-BLAS


Numerical reproducibility failures rise in parallel computation because of the non-associativity of floating-point summation. Optimizations on massively parallel systems dynamically modify the floating-point operation order. Hence, numerical results may change from one run to another. We propose to ensure reproducibility by extending as far as possible the IEEE-754 correct rounding property to larger operation sequences. Our RARE-BLAS (Reproducible, Accurately Rounded and Efficient BLAS) benefits from recent accurate and efficient summation algorithms. Solutions for level 1 (asum, dot and nrm2) and level 2 (gemv) routines are provided. We compare their performance to the Intel MKL library and to other existing reproducible algorithms. For both shared and distributed memory parallel systems, we exhibit an extra-cost of 2× in the worst case scenario, which is satisfying for a wide range of applications. For Intel Xeon Phi accelerator a larger extra-cost (4× to 6×) is observed, which is still helpful at least for debugging and validation.
Fichier principal
Vignette du fichier
SYNASC.pdf (197.39 Ko) Télécharger le fichier
Origin Files produced by the author(s)

Dates and versions

lirmm-01349698 , version 1 (28-07-2016)



Chemseddine Chohra, Philippe Langlois, David Parello. Parallel experiments with RARE-BLAS. SYNASC: Symbolic and Numeric Algorithms for Scientific Computing, Sep 2016, Timisoara, Romania. pp.135-138, ⟨10.1109/SYNASC.2016.032⟩. ⟨lirmm-01349698⟩
252 View
451 Download



Gmail Mastodon Facebook X LinkedIn More