LLVM Clang 12 Leading Over GCC 11 Compiler Performance On Intel Xeon Scalable Ice Lake

Recently we have been running a number of compiler benchmarks looking at the recently released LLVM Clang 12 and GCC 11 open-source code compilers. There is as healthy and competitive competition as ever between GCC and Clang with the mainline Linux kernel these days working well under Clang, more software projects shifting to Clang by default, and the performance being as tight as ever between GCC and Clang for compiled C/C++ code on x86_64 and AArch64. In today's article are benchmarks of Clang 12 vs. GCC 11 on the dual Intel Xeon Platinum 8380 Ice Lake server.

Tests were run with the dual Xeon Platinum 8380 Ice Lake server running the recently released Fedora Server 34, which offers up both GCC 11.1 and LLVM Clang 12.0 as the newest compiler releases of the year.

The CFLAGS/CXXFLAGS set throughout testing were "-O3 -march=native -flto" as would be common for HPC systems when building performance sensitive code. Fedora 34's packaged GCC and Clang builds were tested on this Intel reference Ice Lake 2P server. Via the Phoronix Test Suite a wide range of open-source C/C++ benchmarks were conducted under both compilers.