I got confused on the terminology, and the change in D60598 was not correct. I was thinking of "exact" in terms of the result being non-approximate. However, the relevant distinction here is whether the result is

- Largest range such that: Forall Y in Other: Forall X in Result: X BinOp Y does not wrap. (makeGuaranteedNoWrapRegion)
- Smallest range such that: Forall Y in Other: Forall X not in Result: X BinOp Y wraps. (A hypothetical makeAllowedNoWrapRegion)
- Both. (makeExactNoWrapRegion)

I'm adding a separate makeExactNoWrapRegion method accepting a single APInt (same as makeExactICmpRegion) and using it in the places where the guarantee is relevant.

Sorry for the confusion...