RFR: 8374755: ML-KEM's 12-bit decompression can be simplified on aarch64 [v3]

[Andrew Dinn]

On Mon, 19 Jan 2026 14:01:56 GMT, Ferenc Rakoczi <duke at openjdk.org> wrote:

>> The preconditions for the aarch64 and the AVX-512 intrinsic implementations of the implKyber12To16() method of com.sun.crypto.provider.ML_KEM are different and the AVX-512 one has stricter preconditions on the input, which was not recorded in the assert() before calling the function (although they were satisfied by all calling code). Now the assert() is corrected, and with these preconditions, the aarch64 implementation is simplified.
>
> Ferenc Rakoczi has updated the pull request incrementally with one additional commit since the last revision:
> 
>   improve comment

@wangweij Thanks for sponsoring. While that probably counts implicitly as a review I think you are supposed to actually click the 'reviewed' button to acknowledge that you have reviewed the code.

n.b. Although the PR says only one review is required a Hotspot change actually needs two reviews with at least one (big R) 'Reviewer'.

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PR Comment: https://git.openjdk.org/jdk/pull/29141#issuecomment-3818054364