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

[erifan]

On Fri, 24 Oct 2025 08:52:13 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Ah, I see, thanks for the explanations. Is this documented somewhere in code comments? That would really save you having to explain it repeatedly: you could just point to the code comments ;)
>
> What about `prefers` instead of `uses`? Or `should_use`?

I don't know where there is such a comment, if no, maybe this function is a good place to comment this.

Also I wonder if it's better to return an enum constant? For example:

PREDICATE_MASK
PACKED_MASK
UNPACKED_MASK

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PR Review Comment: https://git.openjdk.org/jdk/pull/27481#discussion_r2459407774