Section: Research Program

Proof of Program Transformations for Multicores

Participants : Éric Violard, Alain Ketterlin, Julien Narboux, Nicolas Magaud, Arthur Charguéraud.

Our main objective consists in certifying the critical modules of our optimization tools (the compiler and the virtual machine). First we will prove the main loop transformation algorithms which constitute the core of our system.

The optimization process can be separated into two stages: the transformations consisting in optimizing the sequential code and in exhibiting parallelism, and those consisting in optimizing the parallel code itself. The first category of optimizations can be proved within a sequential semantics. For the other optimizations, we need to work within a concurrent semantics. We expect the first stage of optimization to produce data-race free code. For the second stage of optimization we will first assume that the input code is data-race free. We will prove those transformations using Appel's concurrent separation logic [57]. Proving transformations involving programs which are not data-race free will constitute a longer term research goal.