[jdk21u-dev] RFR: 8321025: Enable Neoverse N1 optimizations for Neoverse V2

[Xiaolong Peng]

On Fri, 14 Jun 2024 00:22:59 GMT, Xiaolong Peng <xpeng at openjdk.org> wrote:

> ### Notes
> Backport 8321025: Enable Neoverse N1 optimizations for Neoverse V2  to jdk21 it is not a clean backport, the method ```model_is(0xd40) ``` is in jdk21, equivalent code in jdk21 is like ```(_model == 0xd40 || _model2 == 0xd40)```.
> 
> #### Verification
> Not able to test it on CPU with Neoverse V2, since I don't have server supports Neoverse V2 yet, but the fix has been backported to [Amazon Corretto 21](https://github.com/corretto/corretto-21/blob/release-21.0.3.9.1/CHANGELOG.md
> ) since January 16, 2024, overall it should be a low risk.

Thanks Aleksey for reviewing the PR and the suggestions!

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PR Comment: https://git.openjdk.org/jdk21u-dev/pull/720#issuecomment-2177347791