Control flow graph analysis for automatic fast path implementation

A common approach to building high performance protocol software is the implementation of so-called fast paths. A fast path increases the execution speed of the most frequently used path through the protocol software. However, today, a fast path implementation requires extensive manual performance analysis and intuition on behalf of the protocol programmer. This paper presents work in progress whose ultimate goal is to build a protocol compiler that automates fast path implementation. We argue that, starting from a formal description of the protocol, the standard compiler technique of flow graph analysis can be adapted to automatically predict the most frequently executed path in a protocol. This prediction is a prerequisite for automatic fast path implementation. We demonstrate our approach on the automatic implementation of a fast path in presentation conversion routines.