> My zlib implementation for example is consistently 25% faster than the reference version, despite me simply "hand compiling" it straight from the C source. Y

> My zlib implementation for example is consistently 25% faster than the reference version, despite me simply "hand compiling" it straight from the C source. Yeah, but that is a very CPU bound processing pipeline. You would expect that to maximize the impact of any inefficiencies in the compiler. That you can hand tune for better performance is conceivable. That you can get a 2x win over some pretty tuned code suggests that there is something larger at work than simply tuning lots of little things.