LLVM/Clang 3.3 Delivers Speed Improvements
Phoronix: LLVM/Clang 3.3 Delivers Speed Improvements
Last month I delivered benchmarks showing LLVM/Clang 3.3 offers performance improvements and then LLVM/Clang 3.3 is very competitive to GCC 4.8. For further confirming this information, LLVM/Clang 3.3 SVN development benchmarks were carried out from an entirely different system to confirm the earlier findings. LLVM/Clang 3.3 is indeed much faster over its predecessor in a wide variety of Linux benchmarks.
You are still running some of the tests at -O0 (and not -O3 or -Os)
For example, John The Ripper tests are tested using -O0 and not -O3.