Section: Software and Platforms

LAO Developments in JIT Compilation

Participants : Benoit Boissinot, Florian Brandner, Quentin Colombet, Alain Darte, Benoît Dupont de Dinechin [Kalray] , Christophe Guillon [STMicroelectronics] , Fabrice Rastello.

The other side of our work in the STMicroelectronics compiler LAO has been to adapt the compiler to make it more suitable for JIT compilation. This means lowering the time and space complexity of several algorithms. In particular we implemented our fast out-of-SSA translation method, and we programmed and tested various ways to compute the liveness information. Recent efforts also focused on developing a tree-scan register allocator for the JIT part of the compiler, in particular a JIT conservative coalescing. The technique is to bias the tree-scan coalescing, taking into account register constraints, with the result of a JIT aggressive coalescing. See details in the “new results” presented in previous Compsys activity reports.