3 ms·
The prefetcher does a great job, but it's not remotely enough to make stack access penalties disappear. It's trivial to write microbenchmarks where spilling ho
by tux3 11y ago
The prefetcher does a great job, but it's not remotely enough to make stack access penalties disappear.
It's trivial to write microbenchmarks where spilling hot read/write variables to the stack destroys performance, much harder to find special cases where the difference isn't noticeable.
- stephencanon 11y agoThe hot region of the stack is, for practical purposes, always resident in D$, so there's no prefetching to be done. I think that you're really talking about out-of-order and speculative loads. You're absolutely correct that spill/fill can be catastrophic for performance, however.