Our paper tackles these problems in a novel way by focusing on the interaction between an auto-tuner and a parallel application. In particular, we introduce Atune-IL, an instrumentation language that uses new types of code annotations to mark tuning parameters, blocks, permutation regions, and measuring points. Atune-IL allows a more accurate extraction of meta-information to help an auto-tuner prune the search space before employing search algorithms. In addition, Atune-IL’s concepts target parallel applications in general, not just numerical programs.

Atune-IL has been successfully evaluated in several case studies with parallel applications differing in size, programming language, and application domain; one case study employed a large commercial application with nested parallelism. On average, Atune-IL reduced search spaces by 78%. In two corner cases, 99% of the search space could be pruned.