The title question, not anything to do with lea. I at least have never seen a compiler emit a rdtsc. (If there is some case where it does [presumably a benchmarking mode?] I'd be interested to hear of it.)

Heh ;-) I see.

Hmm, can't see it being emitted unless used in profiling code. But then as an inline assembly.

Now rdtscp (notice the "p" at the end) is a fencing instruction as well! So I can see someone using that for barriers or when doing serialization.

(Or I guess if a language somehow include getting a fast spinning counter as a feature that could end up as rdtsc* instruction).