Comparing performance of C compilers optimizations on different multicore architectures

Multithread programming tools become popular for exploitation of high performance processing with the dissemination of multicore processors. In this context, it is also popular to exploit compiler optimization to improve the performance at execution time. In this work, we evaluate the performance achieved by the use of flags -O1, -O2, and -O3 of two C compilers (GCC and ICC) associated with five different APIs: Pthreads, C++11, OpenMP, Cilk Plus, and TBB. The experiments were performed on two distinct but compatible architectures (Intel Xeon and AMD Opteron). In our experiments, the use of optimization improves the performance independently from the API. We observe that the application scheduling performed by the programming interfaces providing an application level scheduler has more impact on the final performance than the optimizations.