If there was a clear distinction between let-bindings and join points, I would be happy. But there is not - there is this contification process and, rather than proving that their algorithm finds all join points, they just say "it covers most of the ground [in practice]", and then they cite (Section 4) two other papers that suggest contification is undecidable - whether a function returns to a specific continuation or function is a behavioral property, not syntactic. Even if you accept that the dominator-based analysis is optimal, it is a global property. not a local property like in a proper IR. So what I see is a muddy mess.