RFR: 8288047: Accelerate Poly1305 on x86_64 using AVX512 instructions [v5]

[Volodymyr Paprotski]

On Fri, 28 Oct 2022 21:55:59 GMT, Jamil Nimeh <jnimeh at openjdk.org> wrote:

>> I flipped-flopped on this.. I already had the code for the exception.. and already described the potential fix. So rather then remove the code, pushed the described fix. Its always easier to remove the extra field I added. Let me know what you think about the 'backdoor' field.
>
> Well, what you're doing achieves what we're looking for, thanks for making that change.  I think I'd like to see that value set on construction and not be mutable from outside the object.  Something like this:
> 
> - place a `private final boolean checkWeakKey` up near where all the other fields are defined.
> - the no-args Poly1305 is implemented as `this(true)`
> - an additional constructor is created `Poly1305(boolean checkKey)` which sets `checkWeakKey` true or false as provided by the parameter.
> - in setRSVals you should be able to wrap lines 296-310 inside a single `if (checkWeakKey)` block.
> - In the Poly1305KAT the `new Poly1305()`  becomes `new Poly1305(false)`.

done

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PR: https://git.openjdk.org/jdk/pull/10582