Comment by raphlinus

I don't allow such rewrites, you have to be explicit. If you write something that doesn't have a valid assembler encoding, its rejected at compile time.

It helps that I'm currently targeting ARM (Cortex M33, RP2350 specifically). Old-school x86 would be much less pleasant, as it's got so many arbitrary-seeming rules of what works and what doesn't. One quirk, when optimizing for file size, are the rules for which instructions have 16 bit encodings and which need 32. But again, the plan is to have a tight feedback loop.