While in our benchmark runs the performance of generated binaries
between GCC and LLVM’s Clang C/C++ compilers are generally quite
close, there are exceptions. When it comes to real-world usage of
Clang, most companies tend to just utilize Clang for now when
producing debug builds due to its faster compile times and better
diagnostics than GCC, but GCC still ends up getting used for
producing release/production builds.
Recently, [ Google
switched to Clang for production builds](http://www.phoronix.com/scan.php?page=news_item&px=MTg0MTk) of their Chrome web
browser. As more good news for the future of Clang, it seems that
Ruby when built under Clang is measurably faster than GCC.
Bráulio Bhavamitra shared that Ruby compiled with Clang 3.5 is 8%
faster than GCC 4.9. However, more impressive is that the lead
jumps to 44% faster when Clang 3.5 is compared to GCC 4.7.2 as
packaged in Debian 7 Wheezy. Details on this Ruby performance
accomplishment for Clang can be found via this