RFR: 8350177: C2 SuperWord: Integer.numberOfLeadingZeros, numberOfTrailingZeros, reverse and bitCount have input types wrongly turncated for byte and short [v6]

[Jasmine Karthikeyan]

On Thu, 26 Jun 2025 06:00:24 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> I ended up encountering `ExtractS` when running `Short128VectorTests.java`, but I thought I should add `ExtractC` to the list as well. Unfortunately I don't think we don't have tests for that one yet because `char` doesn't vectorize yet.
>
> Does it even make sense to vectorize Extract? Is there any case where this actually succeeds? It would be worth filing a follow-up RFE if we don't want to spend the time on this now.

I don't think there's a case where vectorizing Extract can succeed since it's already a vector op (extract scalar out of vector), so this case would only be needed to prevent assert failures.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/25440#discussion_r2174161341