Projet de recherche doctoral numero :4462


Date depot: 1 janvier 1900
Titre: Performance optimization for the LHCb experiment
Directeur de thèse: Lionel LACASSAGNE (LIP6)
Domaine scientifique: Sciences et technologies de l'information et de la communication
Thématique CNRS : Non defini

Resumé: The candidate will analyze some representative algorithms and codes (data intensive computation, control major codes) and design new versions of them for current state-of-the-art parallel architectures: SIMD multi-core processor, GPU and Xeon-Phi. For each architecture, some specific optimizations will be developed. If a straightforward parallelization is inefficient to leverage all the computation power (memory bandwidth issue), the candidate will focus on memory layout optimizations and data management in order to design algorithm with a better throughput. Numerical Stability can also be studied in order to validate previous optimizations. Finally the architectures will be challenged together to determine what is the most appropriate architecture for each type of algorithms. Typical examples are - curves fitting for particule tracking (linear or parabolic trajectography, depending on the particule nature), - kalman filter - pattern recognition algorithms for tracks reconstruction in detector apparatus. The thesis could involve analyzing and transforming the code in order to help the vectorization, and to enhance data locality in caches. These transformations would be loop transformations and HLTs (High Level Transformations) like memory layout change and functions merging

Doctorant.e: Lemaitre Florian