Home > TERATEC FORUM > Workshop 8

TERATEC 2017 Forum
Workshop 8 - Wednesday, June 28 from 14:00 to 17:30

Numerical precision and stability in HPC simulation

VERIFICARLO: An LLVM tool for numerical precision, study in the EUROPLEXUS code.
Pablo OLIVEIRA, UVSQ – LIPARAD et Olivier JAMOND, CEA DEN.

Abstract :   Verficarlo (github.com/verificarlo) is a tool for estimating the numerical precision of simulation codes. It tackles the issue of finding a good tradeoff between good performance and numerical precision of large scale high performance simulation. Verificarlo builds upon the Monte Carlo Arithmetic where arithmetic operators introduce stochastic noise to model roundoff and cancellation numerical errors. Our tool instruments the code at compile time, through a dedicated LLVM pass, without requiring any manual modification of the source code. This facility has permitted the Verificarlo analysis of various industrial simulation codes. In this talk we show analysis results on Europlexus (www-exp.cea.fr) which simulates ast fluid-structure interactions. We show in a buckling use case that non numerical reproducibility can be inherent to certain physical modelisations and is not necessarily a symptom of numerical bugs. By revealing this inherent non-reproducibility, Verificarlo helps the expert choose relevant use cases for numerical regression tests when modernizing or parallelizing a code base.

Bio: Pablo de Oliveira Castro is an assistant professor at the University of Versailles since 2012. In 2010 he received his PhD on Parallel Data Flow Languages at the Commisariat à l'Énergie Atomique. From 2011 to 2012 he was a postdoctoral research fellow at the Exascale Computing Research Lab in France working on auto-tuning for High Performance Computing. His research interests include parallel programming languages, compilers, auto-tuning of high performance applications, and approximate computing. Pablo has a strong involvement in dissemination of his research through open-source software. Contact him at pablo.oliveira@uvsq.fr.
   
  Bio: Olivier Jamond works as an engineer-researcher at the CEA (French public-funded research organization in the areas of energy, defense and security, information technologies and health technologies) since 2013. He obtained his PhD in 2011 in the field of numeric simulation in mechanics for his work on a coupling between finite-elements numerical models. From 2011 to 2013, he was a postdoctoral fellow at ONERA (French public government-funded research organization in the area of aerospace) where he worked on a coupling between finite-elements and discrete dislocation dynamics. Today, he still works mainly on the coupling between different numerical models, and especially on immersed boundaries approaches for fluid-structure interaction.

Register now and get your badge here

  • TERATEC Forum is strictly reserved for professionals.
  • Participation to exhibition, conferences and workshops is free (subject to seats available)
  • On line registration is obligatory to attend exhibition, conferences or the workshops.
  • The Vigipirate security plan being raised to its highest level, it is mandatory to register online in advance and come with an identity card order to participate in TERATEC Forum.
  • The badge is free of charge and give you access to all events TERATEC Forum.

For any other information regarding the workshops, please contact :

Jean-Pascal JEGU
Tel : +33 (0)9 70 65 02 10
jean-pascal.jegu@teratec.fr
Campus TERATEC
2, rue de la Piquetterie
91680 BRUYERES-LE-CHATEL
France


 

© Ter@tec - All rights reserved - Lawful mention