Handling out-of-bounds AArch64 immediates about dynasm-rs HOT 1 OPEN

Hey! glad to hear someone else using this!

Such a check is already in place for things that can be resolved at compile time. At run-time it's a bit more complex, especially for aarch64 due to the sheer amount of immediates it uses.

It might also be a bit of a perf hit, so I'm wondering if it could be enabled conditionally. Thinking about a design for that, but I don't have immediate answers.

Either way, a good starting point would be here. This is where immediates are handled, compile-time checks are often done, and the runtime code is generated.

There's also likely a bit of run-time support necessary. There's already some precedent for that in the aarch64 module in the handling of special immediates.

from dynasm-rs.