Conversation

I just merged the PyPy "known bits" JIT optimization that Nico Rittinghaus and I worked on in the last two years. It allows the JIT to reason about specific bits of integer variables that are known to be 0 or 1. This makes bit-manipulation code faster, sometimes significantly so.

A concrete example of something the JIT now knows, but didn't before: if you add two even integers together, you get an even result.