I want a good FP language that runs on an HVM. So I'm taking the HVM3 implementation and modifying to have the features I want. Check out the HVM3 Repo for the details of how it works first.
Terms are always 64-bits wide with a Tag in the lower 4 bits, giving 16 different possible tags.
There are two tags for number terms, I60 and F60 for 60-bit integer and floats.