Poster: Reordering Tests for Faster Test Suite Execution

As software takes on more responsibility, it gets increasingly complex, requiring an extremely large number of tests for effective validation. Executing these large test suites is expensive, both in terms of time and energy. Cache misses are a significant contributing factor to execution time of software. In this paper, we propose an approach that helps order test executions in a test suite in such a way that instruction cache misses are reduced, and thereby execution time. We conduct an empirical evaluation with 20 subject programs and test suites from the SIR repository, EEMBC suite and LLVM Symbolizer, comparing execution times and cache misses with test orderings maximising instruction locality versus a traditional ordering maximising coverage, as well as random permutations. Performance gains were considerable for programs and test suites where the average number of different instructions executed between tests was high. We achieved an average execution speedup of 6.83% and a maximum execution speedup of 17% over subject programs with differing control flow between test executions.