We do still read code. => We do still read Assembly code in the world of compilers.

Deterministic vs None-Deterministic

Heck, OpenAI can't even get their models to reliably do what they intend, so yeah.

AOT without PGO, manual memory management, traditional optimisations vs AOT with PGO, JIT, tracing GC, machine learning optimisation passes.

Which have what to do with the relationship between the assembly and the higher level language?

It is the answer to you Deterministic vs None-Deterministic.

If you don't get the difference, I get there isn't much that you know about how instruction selection works, across all those approaches.

Ok, I feel you know what this is actually about, but here spelled out:

Do any of the optimizations you mentioned affect the underlying behavior of the run code? Does the source ever lead to a different observable behavior? If not, it doesn't fit to LLM use, where this is very much the case.

There is the observable behaviour, and the machine code instructions that actually get generated in every single case for the same kind of text input.

Which for example, unless you can exactly replicate the world every single time a PGO data gathering session is done, there are no guarantees that the compiler will generate exactly the same machine code pattern, when given various PGO files generated at different occurrences.

Thanks, yes. To get back to the "We do still read Assembly code in the world of compilers" analogy, in the case of LLM usage, the observable behaviour is...

Assembly naturally,

https://www.phoronix.com/news/Frame-X11-Server-Assembly

Not seeing it. “We do still read code” implies neither that every single person does, nor that they need to master the language being read. Taken together, it sems to me that you need a fair bit of extrapolation to make the analogy work.