Personal page of Guillaume Iooss

I am currently a Post-Doctorate at Inria (team Corse in Grenoble), working on polyhedral model. I previously worked on synchronous language (with team Parkas in Paris) and the Heptagon compiler.

My topics of interest is compilation. More precisely: the polyhedral model, tiling, program equivalence (and using semantic properties in a compiler) and synchronous languages.

Contact informations:

  • Professional email:
  • (Outdated) Work office: C334 - Campus Minatec - Grenoble
  • Phone: (+33)601813891
  • I am also on Github

Ma photo

Research

  • Post-doctorate at Corse (Grenoble): I have just started a post-doctorate with team Corse in Grenoble.
  • Post-doctorate at Parkas (Paris): My current post-doctorate is about synchronous language, in the context of the project Assume. The goal is to map industrial applications into the Kalray MPPA. I am mainly working on the front-end aspect, by exploiting the harmonic multirate aspects of the periodic clocks of the applications. I am working with the Heptagon compiler for this project, and in collaboration with Airbus and Safran. I am also working on a OpenCL backend to the Heptagon compiler (project Redefine), in order to offload computations on an accelerator.
  • PhD: "Detection of linear algebra operations in polyhedral programs" (Dissertation / Slides of the defense). My PhD was a cotutelle between ENS Lyon (advisers: Christophe Alias, Alain Darte/ team: Compsys) and Colorado State University (adviser: Sanjay Rajopadhye / team: Melange). This work contains mainly two contributions: the monoparametric tiling (also called Constant Aspect Ratio Tiling), a parametric tiling in the polyhedral model, and a template recognition algorithm, which can manage semantic properties commonly encountered in linear algebra (in particular the associativity and commutativity properties of reduction operators). These contributions were combined in order to recognize automatically tiles of the program as combination of BLAS library calls.

List of publications

  • Journal articles:
    • Keryan Didier, Dumitru Potop-Butucaru, Guillaume Iooss, Albert Cohen, Jean Souyris, Philippe Baufreton, and Amaury Graillat. Correct-by-Construction Parallelization of Hard Real-Time Avionics Applications on Off-the-Shelf Predictable Hardware. In ACM Transactions on Architecture and Code Optimization (TACO), Volume 16, Number 3 (August 2019)
  • Conference articles:
    • Guillaume Iooss, Christophe Alias, and Sanjay Rajopadhye. On program equivalence with reductions. In 21st International Static Analysis Symposium (SAS'14), Munich, Germany, September 2014.
    • Lucas W. Krakow, Louis Rabiet, Yun Zou, Guillaume Iooss, Edwin K. P. Chong, and Sanjay Rajopadhye. Optimizing dynamic resource allocation. In Proceedings of the International Conference on Computational Science, ICCS 2014, Cairns, Queensland, Australia, 10-12 June, 2014, pages 1277--1288, May 2014.
  • International workshop:
  • Technical report:
    • Keryan Didier, Dumitru Potop-Butucaru, Guillaume Iooss, Albert Cohen, Jean Souyris, Philippe Baufreton, Amaury Graillat. Parallelisation efficace de larges applications temps-reel. Research Report, RR-RR-9180, INRIA, 2018.
    • Tian Jin, Nirmal Prajapati, Waruna Ranasinghe, Guillaume Iooss, Yun Zou, Sanjay Rajopadhye and David G. Wonnacott. Hybrid Static/Dynamic Schedules for Tiled Polyhedral Programs. Research Report, 2016
    • Guillaume Iooss, Sanjay Rajopadhye, Christophe Alias, Yun Zou. Mono-parametric Tiling is a Polyhedral Transformation. Research Report, RR-8802, INRIA, 2015.
    • Sanjay Rajopadhye, Guillaume Iooss, Tomofumi Yuki, and Dan Connors. The stencil processing unit: GPGPU done right. Technical report, Colorado State University, March 2013.
    • Tomofumi Yuki, Vamshi Basupalli, Gautam Gupta, Guillaume Iooss, DaeGon Kim, Tanveer Pathan, Pradeep Srinivasa, Yun Zou, and Sanjay Rajopadhye. AlphaZ: A system for analysis, transformation, and code generation in the polyhedral equational model. Technical report, Colorado State University, May 2012.
  • Posters:

Implementations

  • Standalone version of CART (on polyhedron and affine function): Github repository (integrated inside a C compiler)
  • Various transformations in the AlphaZ compiler
  • Various transformations in the Heptagon compiler (especially in the "onesync", and the "opencl-redefine" branches)

Community service

Teaching (TD/TP):