The Cinder JIT compiler utilizes a unique approach to representing types by treating them as sets and using a compact representation. By thinking of types as lattices, the compiler aims to optimize operations for speed when manipulating types. Through the use of enums and bitsets, Cinder can efficiently handle type unions and class hierarchies. Additionally, Cinder introduces the concept of specialization, tracking specific object values within the type lattice. The compiler’s approach involves managing Bottom types and ensuring correct handling of specialized values, ultimately aiming to streamline optimizations and improve performance. Note: Some technical details are omitted for brevity.
https://bernsteinbear.com/blog/lattice-bitset/