GCC 8/9 vs. LLVM Clang 6/7 Compiler Benchmarks On AMD EPYC

In the case of FLAC audio encoding, Clang was faster at -O3 -march=native while losing to GCC at the lower optimization levels.

Of 49 benchmarks ran in total across the four tested compilers at the three optimization levels, coming in first at 34% of the time was GCC 8.2 RC1 with the obvious "-O3 -march=native" level while coming in second with wins 20% of the time was LLVM Clang 6.0 with the similar "-O3 -march=native" level while in third with wins 16% of the time was GCC 9.0 SVN at the same optimization level. LLVM Clang performance has come a long way over the past few years and is generally on-par with GCC these days, but as these benchmark results show, there still are many cases where the GNU Compiler Collection can offer a measurable advantage over Clang for the performance of generated binaries from C/C++.