RFR: 8367292: VectorAPI: Optimize VectorMask.fromLong/toLong() for SVE [v3]

[Emanuel Peter]

On Tue, 28 Oct 2025 10:20:49 GMT, Xiaohong Gong <xgong at openjdk.org> wrote:

>> Yes, these are a step int the right direction! :)
>> 
>> Thanks a lot for the explanations, very helpful! Please make sure that they are all represented in the code comments, so we don't lose them to this GitHub thread!
>> 
>> `// Identify if a vector mask operation requires the input/output mask to be`
>> The language of `requires` slipped again into your explanation. Is that intended? Probably not?
>> You should use a condensed version from your GitHub comments above, I think that would be very helpful :)
>
> Current comment might be confusing. I will use `requires` both in comments and method name. Hope this would be more clear. WDYT?

Well, we went with `prefers` because you said that on `aarch64` both are implemented, see our conversation above. So we are now spinning in circles.

I would approach it like this:
Write down what it means if the method returns true, and what it means if it returns false. Make sure to use `requires`, if anything else is not permitted/implemented. Use `prefers` if both are permitted/implemented, but one is preferred.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27481#discussion_r2468923970