RFR: 8360934: Add AVX-512 intrinsics for ML-KEM - enhancement on AVX512_VBMI [v2]

[Shawn M Emery]

On Wed, 7 Jan 2026 18:59:16 GMT, Ferenc Rakoczi <duke at openjdk.org> wrote:

>> Yep, thats exactly the assert I was looking at as well.. looks to me like its dividing the 'expanded-short-array-length' by 64 and ensuring the remainder is zero (ignoring the 48 for a bit.. and the condensed-length check).
>> 
>> (for simplicity) So the 'expanded' array length should be a multiple of 64; i.e. 128-bytes. But we stride the expanded array by 256 bytes? (and parsedLength by 128-shorts..)
>> 
>> I haven't checked the callers of `twelve2Sixteen` but I suspect that the length of the expanded array is always a multiple of 256-bytes (128-shorts).. in which case, the assert is 'incomplete'?
>
> Oooops, yes, the assert and the comment on twelve2sixteen() should be fixed. All of the calls are processing 192 or 384 bytes (and producing 128 or 256 shorts). The comment and assert belonged to an earlier version and were not updated when I changed my mind about the implementation.

I've filed bug:

[JDK-8374755](https://bugs.openjdk.org/browse/JDK-8374755) ML-KEM's 12-bit decompression uses incorrect assertions

to track this issue.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28815#discussion_r2670893072