I grilled an LLM for a bit to see if it could justify the old forward progress rule. The only thing I got that passed the smell test was that it’s useful for the optimizer to be able to optimize:

    messy_pure_computation();
    some_atomic.store(1, relaxed);

by moving the store before the computation. (Stronger stores would require additional analysis.)

I admit I’m unconvinced that this is particularly useful.

(I got many other ideas that did not pass my personal smell test.)