What amazes me is that they do not test this extremely specific uarch code when a new uarch is released. On the other hand, I think the hack is not in using th

What amazes me is that they do not test this extremely specific uarch code when a new uarch is released. On the other hand, I think the hack is not in using the pause instruction itself, but that crazy backoff algo. For example Linux uses pause too (via rep; nop) in lots of places. But not in a exponential loop (that I'm aware of).