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

Following the GCC 9.0 benchmarks earlier this week I ran some tests seeing how the GCC 8 stable compiler and GCC 9 development state compare to the LLVM Clang 6.0.1 stable compiler and LLVM Clang 7.0 development. Here are those benchmarks using the AMD EPYC 7601 32-core / 64-thread processor.

Up for benchmarking in this Linux C/C++ compiler comparison were GCC 8.2 RC1, GCC 9.0.0 SVN as of 20 July, LLVM Clang 6.0.1 stable, and LLVM Clang 7.0 SVN as of 22 July. With each of these compilers, they were tested when setting the CFLAGS/CXXFLAGS to -O2, -O3, and -O3 -march=native for a variety of common optimization levels.

The test system for the duration of the comparison was the AMD EPYC 7601 "Zen" server processor within a Tyan 2U platform and running an Ubuntu 18.10 development snapshot with the Linux 4.16 kernel.

All of these compiler benchmarks were carried out in a fully-automated and reproducible manner using the open-source Phoronix Test Suite benchmarking software.