(team Mill)

> "magic" circular buffers mapped twice in a row so that any size and position block is contiguous

Yes this exact case is one of those that won't work. There are a handful of other things that don't work, like people who roll their own coroutines using assembler. We promise 'don't rewrite, just recompile' but your codebase has to be 64-bit clean and not use any assembly language for any other ISA and not make other unportable assumptions about the hardware.

I can't think of any software that actually uses these circular buffers that wouldn't be worth adapting to the Mill rather than adapting the Mill to them; can you? ;)