RFR: 8343689: AArch64: Optimize MulReduction implementation [v8]

[Mikhail Ablakatov]

On Fri, 11 Jul 2025 06:15:31 GMT, Xiaohong Gong <xgong at openjdk.org> wrote:

>> Precisely that, @shqking , thank you. I found this while evaluating the effect the patch has on auto-vectorization.
>
> I see. Thanks! So what is the type of bt? Is it an integer type of floating-point one? If it's an integer type, I think changing or not does not have difference. But if it is floating-point type, we do not support the non-strict-ordered anyway and they are not enabled in SLP on AArch64. I'm just curious whether this change has any relationship with this PR. If not, I suggest not touching it now. Seems there is the same change in this PR https://github.com/openjdk/jdk/pull/23181.

@XiaohongGong , JIC, you've referenced the PR you left this comment in. Did you intend to post it somewhere else?

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PR Review Comment: https://git.openjdk.org/jdk/pull/23181#discussion_r2199910206