Okay, I'm confused, I thought that the whole point of a caller saves, continuation passing regime was that the caller only saves what it's interested in using after the function returns. Exactly *where* that return happens, and whether it happens more than once, is completely irrelevant from the point of view of the caller. ISTM that the register allocator should work on the principle that anything it didn't save before it made the call will be toast afterwards. Doing anything more sophisticated than optimizing register allocation on a sub by sub basis seems like a license for getting completely and utterly plaited.
Or am I missing something fundamental?
