Section: Overall Objectives

Summary of Compsys I Achievements

The Compsys team has been evaluated by Inria for the first time in April 2007. The evaluation, conducted by Erik Hagersted (Uppsala University), Vinod Kathail (Synfora, inc), J. (Ram) Ramanujam (Baton Rouge University) was positive. Compsys I thus continued into Compsys II for 4-5 years but in a new configuration as Tanguy Risset and Antoine Fraboulet left the project to follow research directions closer to their host laboratory at Insa-Lyon. The main achievements of Compsys I, for this period, were the following:

• The development of a strong collaboration with the compilation group at STMicroelectronics, with important results in aggressive optimizations for instruction cache and register allocation.

• New results on the foundation of high-level program transformations, including scheduling techniques for process networks and a general technique for array contraction (memory reuse) based on the theory of lattices.

• Many original contributions with partners closer to hardware constraints, including CEA, related to SoC simulation, hardware/software interfaces, power models, and simulators.

Due to Compsys size reduction (from 5 permanent researchers to 3 in 2008, then 4 again in 2009), the team then focused, in Compsys II, on two research directions only:

• Code generation for embedded processors, on the two opposite, though connected, aspects: aggressive compilation and just-in-time compilation.

• High-level program analysis and transformations for high-level synthesis tools.