RFR: 8349721: Add aarch64 intrinsics for ML-KEM [v7]

[Andrew Dinn]

On Thu, 10 Apr 2025 13:19:05 GMT, Ferenc Rakoczi <duke at openjdk.org> wrote:

>> By using the aarch64 vector registers the speed of the computation of the ML-KEM algorithms (key generation, encapsulation, decapsulation) can be approximately doubled.
>
> Ferenc Rakoczi has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Code rearrange, some renaming, fixing comments
>  - Changes suggested by Andrew Dinn.

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 5684:

> 5682:     VSeq<2> vs5(vs3[1], delta);
> 5683:     kyber_montmul16(vs5, vz, vs5, vs_front(vs2), vq);
> 5684:     // add results in pairs storing in vs3

Suggestion:

    // add results in pairs storing in vs3
    // vs3[0] <- montmul(a0, b0) + montmul(montmul(a1, b1), z0);
    // vs3[1] <- montmul(a0, b1) + montmul(a1, b0);

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 5686:

> 5684:     // add results in pairs storing in vs3
> 5685:     vs_addv(vs_front(vs3), __ T8H, vs_even(vs3), vs_odd(vs3));
> 5686:     vs_addv(vs_back(vs3), __ T8H, vs_even(vs1), vs_odd(vs1));

Suggestion:

    // vs3[2] <- montmul(a2, b2) + montmul(montmul(a3, b3), z1);
    // vs3[3] <- montmul(a2, b3) + montmul(a3, b2);
    vs_addv(vs_back(vs3), __ T8H, vs_even(vs1), vs_odd(vs1));

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 5687:

> 5685:     vs_addv(vs_front(vs3), __ T8H, vs_even(vs3), vs_odd(vs3));
> 5686:     vs_addv(vs_back(vs3), __ T8H, vs_even(vs1), vs_odd(vs1));
> 5687:     // montmul result by constant vc and store result in vs1

Suggestion:

    // vs1 <- montmul(vs3, montRSquareModQ)

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/23663#discussion_r2044712516
PR Review Comment: https://git.openjdk.org/jdk/pull/23663#discussion_r2044714830
PR Review Comment: https://git.openjdk.org/jdk/pull/23663#discussion_r2044726778