Doc: what does CPU() do ?

Thank you for this beautiful library !

In contrast with another recent issue I'm finding rather large speedup for the CPU kernel that I have implemented. The doc does not say anything that might explain it. Is it using oneAPI.jl or some other smart Julia rewrite ?

In my application (some form of dynamic optimization) I have a large loop, that is conceptually SIMD even though I'm using higher level constructs which apparently prevent it from being automatically vectorized (even with @simd keyword). It does not allocate.

Using Julia's Threads I get a X6 speedup (I have 8 cores) over the monocorde version.
Using KA/CPU kernels I get a X12 speedup.

The second KA/CPU seems rather efficient and suggests some degree of vectorization but I don't find a way to confirm my suspicion. I'd it what happens ?

Sorry not to provide a minimal working example. I could work out one with some effort but would like to know first how suspicious I should be or nicer than expected results.

No file or test is named. Start by locating the CPU kernel documentation and the CPU kernel entry point, then compare its behavior with Julia Threads and @simd as described in the issue. Done means the documentation explains what CPU() does and how a user can verify the suspected vectorization or speedup.