LLVM Clang Achieves ~96% The Performance Of GCC On Intel Ice Lake

The LLVM Clang compiler continues becoming increasing competitive against the long-standing GNU Compiler Collection (GCC) on Linux x86_64 systems... With tests done on Intel Ice Lake using the Core i7-1065G7, the Clang 9.0 stable performance is delivering over 95% the performance of GCC 9 stable based on over 40 C/C++ benchmarks.

Recently I wrapped up some LLVM Clang vs. GCC stable Linux x86_64 benchmarks using the Core i7-1065G7 "Ice Lake" processor and was quite impressed with the results for how close Clang was competing with GCC.

Tests on GCC 10 vs. Clang 10 development versions will be coming shortly as well as on alternative Intel/AMD processors.

Of 41 benchmarks ran on both compilers, LLVM Clang 9.0 actually came in first place in 22 (53.6%) of the tests to GCC's 19 wins. Winning the majority of the tests is quite a feat.

When taking a look at the geometric mean of those 41 benchmarks, GCC 9.2.1 still came out slightly ahead on this Ice Lake + Ubuntu 19.10 system, but just a few percent faster. Seeing LLVM Clang deliver 96% the performance of GCC on a modern Intel x86_64 processor is the best showing we have seen out of Clang when it comes to running it across many different workloads.

There are some cases where GCC 9's performance is winning by big margins compared to Clang, but the more liberal compiler also had its share of sizable wins too.

Those wanting to dig through these benchmark results for all the data in full can do so via this OpenBenchmarking.org result file while awaiting other end-of-year compiler testing on Phoronix.