The point is that expert humans (the GCC developers) writing code (C++) that generates code (ASM) does not appear to be as deterministic as you seem to think it is.
Classic HN-ism. To focus on the semantics of a statement while ignoring the greater point in order to argue why someone is wrong.
I’m very aware of that, but I’m also aware that it’s rare enough that the compiler doesn’t emit semantically equivalent code that most people can ignore it. That’s not the case with LLMs.
I’m also not particularly concerned with non-determinism but with chaos. Determinism in LLMs is likely solvable, prompt instability is not.