GCC vs. LLVM Clang Compiler Performance On AMD's Ryzen

Both GCC 7.0 and LLVM Clang 4.0 had regressed with FFTW compared to GCC 6.3 and Clang 3.9.1, respectively. Clang 3.9.1 ended up coming out slightly ahead of GCC on this Ryzen box.

With MAFFT, the testing was a close race between GCC 6.3 and Clang 4.0.

LLVM Clang continues to lead over GCC with the SciMark2 testing.

GCC does well with SciMark's FFT sub-test and Monte Carlo while Clang usually takes the cake in the other SciMark micro tests.