This talk gives an overview of the key ideas behind Unison. The video includes a demo showing how Unison can improve the speed of the code generated by LLVM (a state-of-the-art compiler) for Hexagon (a digital signal processor ubiquitous in modern mobile platforms):

This talk illustrates how Unison can identify improvement opportunities in the LLVM heuristic algorithms:

A shorter version of the demo can be seen here: