Statistical selection of compiler options

Compilers have many switches or options that enable certain code optimizations. However, it is well known that the optimal set of options to be turned on is dependent on both the application and the target architecture. In many cases, standard settings, like -O3, produce suboptimal results due to negative interference of some of the options they contain. We propose an automatic iterative procedure to turn on or to turn off compiler options. This procedure is based on orthogonal arrays that are used for a statistical analysis of profile information to calculate the main effect of the options. We show that our approach outperforms -O3 of GCC on six SPEC benchmarks.