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

[Weijun Wang]

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

Didn't notice the reviewer count. Maybe the Skara bot hasn't enforced it. Otherwise, it should not add the `ready` and `sponsor` labels.

I typed `/sponsor` mainly because I trust Ferenc' code and reviews from you and Shawn. I don't think a sponsor has to review the code change themselves.

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PR Comment: https://git.openjdk.org/jdk/pull/29141#issuecomment-3818252537