RFR: 8371459: [REDO] AArch64: Use SHA3 GPR intrinsic where it's faster [v3]

[Paul Hohensee]

On Wed, 18 Feb 2026 15:46:00 GMT, Boris Ulasevich <bulasevich at openjdk.org> wrote:

>> This change revises a previous update to enable the SHA3 GPR intrinsic as an alternative to the SHA3 extension–based intrinsic on platforms where it performs better. In practice, it is enabled only on Apple and Qualcomm silicon. See the previous PR for measurement details: https://github.com/openjdk/jdk/pull/27726
>> 
>> Tests were updated accordingly: now UseSHA3Intrinsics can be enabled on AArch64 even without the SHA3 CPU capability.
>> 
>> The test TestUseSHA3IntrinsicsOptionOnSupportedCPU.java was also enabled on AMD as this platform supports the intrinsic.
>> 
>> With the VM run with -XX:-UseSHA -XX:+UseSHA3Intrinsics, the test expects the VM to print `Intrinsics for SHA3-224, SHA3-256, SHA3-384 and SHA3-512 crypto hash functions not available on this CPU`. For SHA3, the message is changed to `UseSHA3Intrinsics requires that UseSHA is enabled`, and the test is updated to check only for the presence of "warning:" in the output.
>> 
>> Testing on platforms
>> - AMD (machines with and without SHA3 CPU capability)
>> - AARCH (Apple CPU and Neoverse machines with and without SHA3 CPU capability)
>> 
>> Recent updates on the same functionality:
>> - https://github.com/openjdk/jdk/pull/29266
>> - https://github.com/openjdk/jdk/pull/29645
>
> Boris Ulasevich has updated the pull request incrementally with one additional commit since the last revision:
> 
>   updating recent tests

Marked as reviewed by phh (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/28515#pullrequestreview-3849512194