From cTuning.org
Google Summer of Code 2009: Generic function cloning. Liang Peng Based on Run-time Function Adaptation for Statically-Compiled Programs based on function multiversioning and FunctionSpecificOpt, we enabled generic function cloning with low-overhead program behavior monitoring routines. And it will enable fine-grain self-tuning binaries and libraries and will increase performance and portability of the static code which is particularly important for rapidly evolving hardware and virtual enviroments.