Yes, the same compiler generates the same output given the same input. I'd be willing to put a large amount of money on that result.

I read a lot of assembly.

I was more after the fact i can trust the compiler to give me the same result - even though via an optimized path.

Certainly scopes vary, but in my line of work i define memory layout and how this data will be processed myself - thus it's great a compiler might do that, but the result of the computation will not change.

Now in comparison giving an LLM specs ... i a) cannot be sure what the computation will be b) it might be something else on another run.