Why aren't we using git like hashes for compilers? Take referentially transparent parts of code, blob together and make a hash of the AST in a canonical form an

Why aren't we using git like hashes for compilers? Take referentially transparent parts of code, blob together and make a hash of the AST in a canonical form and a hash of the assembly, source, transforms used, and benchmark stats. The compiler would run continiously searching for new solutions.