Section: New Results

Semantics diffs in LLVM

Participants : Laure Gonnord, Matthieu Moy.

Laure Gonnord and Matthieu Moy have coadvised a Master research Project (“TER”) early in 2019 , whose objective was to study the LLVM LLVM compiler infrastructure with software engineering techniques in order to characterise how sequences of code analyses and transformations behave. The project has lead to a sequence of tools to evaluate experimentally how a sequence of passes influence performance.

Laure Gonnord and Matthieu Moy have, together with Sebastien Mosser, coadvised a second internship at UQAM for three months, between May and July 2019. During his internship, Sebastien Michelland has demonstrated that textual diffs are not sufficient to fully characterise the behaviours of code transformation inside compilers. He analysed llvm-diff, a tool of the distribution that makes an analysis at the intermediate representation level, and gives first hints to define a proper notion of semantic diff for this application.

For these interships two research reports have been produced.

This work was done in the context of an ongoing collaboration with Sebastien Mosser, previously in Nice, and now at UQAM. An Inria associate team was proposed for 2020-2023 on similar topics.