Unison is a simple, flexible, and potentially optimal tool that performs integrated register allocation and instruction scheduling using constraint programming as a modern method for combinatorial optimization.
Unison can be used as an alternative or as a complement to the algorithms provided by the state-of-the-art LLVM compiler. Why? How? Check out this short video:
To learn more about Unison, check out the Videos section or read how Ericsson uses the tool.