Module context_map 

ContextMap – hash table mapping context hashes to states.

Phase 4: Three variants:

1. Simple lossy ContextMap (1 byte per entry, for low-order models)
2. ChecksumContextMap (2 bytes: checksum + state, reduces collisions)
3. AssociativeContextMap (4 bytes: 2 slots with checksums, lowest collision)

Structs

AssociativeContextMap

2-way set-associative context map: 4 bytes per set (2 slots).

ChecksumContextMap

Checksummed context map: 2 bytes per entry (checksum + state).

ContextMap

Simple lossy hash table mapping context hashes to state bytes.