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 5590:

> 5588:     __ add(tmpAddr, coeffs, 0);
> 5589:     store64shorts(vs2, tmpAddr);
> 5590: 

I'd like to make explicit the fact that we have avoided doing an add here (and in the next two cases) by adding a commented out generation step i.e. at this line insert

    // __ add(tmpAddr, coeffs, 128); // unneeded as implied by preceding load

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 5595:

> 5593:     __ add(tmpAddr, coeffs, 128);
> 5594:     store64shorts(vs2, tmpAddr);
> 5595: 

Likewise insert:

    // __ add(tmpAddr, coeffs, 256); // unneeded as implied by preceding load

src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 5601:

> 5599:     store64shorts(vs2, tmpAddr);
> 5600: 
> 5601:     load64shorts(vs1, tmpAddr);

Likewise insert:

    // __ add(tmpAddr, coeffs, 384); // unneeded as implied by preceding load

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

PR Review Comment: https://git.openjdk.org/jdk/pull/23663#discussion_r2037607688
PR Review Comment: https://git.openjdk.org/jdk/pull/23663#discussion_r2037609104
PR Review Comment: https://git.openjdk.org/jdk/pull/23663#discussion_r2037611049