Section: Partnerships and Cooperations

International Initiatives

Collaboration with Colorado State University

Compsys had always kept strong connections with Colorado State University (CSU):

• In July 2016, Guillaume Iooss defended his joint ENS-Lyon/CSU PhD thesis [16]. He was co-advised by both Sanjay Rajopadhye (CSU) and Christophe Alias (with supplementary support by Alain Darte for administrative reason, as he has no HDR yet).

• Tomofumi Yuki, who did his PhD with Sanjay Rajopadhye, then a post-doc in the Cairn team in Rennes, continued his collaboration with these two groups, as the results described in Section 7.5 illustrate. He also participates regularly, over the net, to the reading group “Melange” of S. Rajodapdhye's group, with CSU students. Due to the stop of Compsys, Tomofumi Yuki has now returned to the Cairn team.

• Waruna Ranasinghe, a PhD student from S. Rajopadhye's team, visited Compsys, to work with Tomofumi Yuki, for 2 months (see Section 9.5).

Polyhedral Community

In 2011, as part of the organization of the workshops at CGO’11, Christophe Alias (with Cédric Bastoul) organized IMPACT’11 (international workshop on polyhedral compilation techniques, http://impact2011.inrialpes.fr/). This workshop in Chamonix was the very first international event on this topic, although it was introduced by Paul Feautrier in the late 80s. Alain Darte gave the introductory keynote talk. After this successful edition (more than 60 people), IMPACT continued as a satellite workshop of the HIPEAC conference, in Paris (2012), Berlin (2013), Vienna (2014). Alain Darte was program co-chair and co-organizer of the 2015 edition in Amsterdam, and Tomofumi Yuki of the 2016 edition in Prague.

The creation of IMPACT, now the annual event of the polyhedral community, helped to identify this community and to make it more visible. This effort was complemented by the organization by Alain Darte of the first school on polyhedral code analysis and optimizations (http://labexcompilation.ens-lyon.fr/polyhedral-school/). A second polyhedral school (https://mathsinfohpc.sciencesconf.org), more open, because involving themes and researchers from numerical analysis (users of HPC), was organized in 2016 by Alain Darte (for the compiler side) and Violaine Louvet (for the HPC side). See details in Section 10.1.

Alain Darte also manages two new mailing lists for news (polyhedral-news@listes.ens-lyon.fr) and discussions (polyhedral-discuss@listes.ens-lyon.fr) on polyhedral code analysis and optimizations. Tomofumi Yuki is involved in the development of PolyBench (http://sourceforge.net/projects/polybench), a suite of kernels used for illustrating polyhedral optimizations. He is also developing PolyApps, a set of larger applications to evaluate the gap between kernels and “real” applications, see more details in Section 7.7.