GCC 4.8.0 vs. LLVM Clang 3.3 Compiler Performance Three-Way
In preparation for the upcoming release of LLVM 3.3, here is an extensive round of C/C++ benchmarks from GCC 4.8.0, LLVM Clang 3.2, and LLVM Clang 3.3-rc1 to look at the Linux compiler performance. Benchmarks happened from three different systems bearing Intel Core i7 3960X, AMD FX-8350, and Intel Core i3 3217U processors for a diverse look at the performance.
LLVM Clang 3.3 brings many new features to the innovative multi-platform open-source compiler infrastructure and earlier benchmarks on Phoronix have found it to be noticeably faster in some scenarios. This is great competition to the GCC 4.8.0 release that happened in late March and a worthwhile successor to the December release of LLVM 3.2.
The systems used for benchmarking included coverage of the Intel Core i7 3960X "Sandy Bridge" Extreme Edition, AMD FX-8350 "Vishera" (Bulldozer 2), and Intel Core i3 3217U "Ivy Bridge" processors. Testing of these three systems isn't meant to compare each other in a competitive manner but simply a diverse range of x86 CPU architectures to stress by LLVM Clang 3.3 in looking for performance changes. These three systems were running Ubuntu Linux x86_64.
The CFLAGS/CXXFLAGS were maintained the same throughout testing GCC 4.8.0, LLVM Clang 3.2, and LLVM Clang 3.3 RC1. All three compilers were built from source on each system in a performance-optimized debugging-disabled state. All of this compiler benchmarking was handled in a fully automated and reproducible manner using the open-source Phoronix Test Suite software.