RFR: 8288047: Accelerate Poly1305 on x86_64 using AVX512 instructions [v7]

[Jamil Nimeh]

On Fri, 4 Nov 2022 03:20:11 GMT, Volodymyr Paprotski <duke at openjdk.org> wrote:

>> Handcrafted x86_64 asm for Poly1305. Main optimization is to process 16 message blocks at a time. For more details, left a lot of comments in `macroAssembler_x86_poly.cpp`.
>> 
>> - Added new KAT test for Poly1305 and a fuzz test to compare intrinsic and java.
>>   - Would like to add an `InvalidKeyException` in `Poly1305.java` (see commented out block in that file), but that conflicts with the KAT. I do think we should detect (R==0 || S ==0) so would like advice please.
>> - Added a JMH perf test.
>>    - JMH test had to use reflection (instead of existing `MacBench.java`), since Poly1305 is not 'properly' registered with the provider.
>> 
>> Perf before:
>> 
>> Benchmark                   (dataSize)  (provider)   Mode  Cnt        Score        Error  Units
>> Poly1305DigestBench.digest          64              thrpt    8  2961300.661 ± 110554.162  ops/s
>> Poly1305DigestBench.digest         256              thrpt    8  1791912.962 ±  86696.037  ops/s
>> Poly1305DigestBench.digest        1024              thrpt    8   637413.054 ±  14074.655  ops/s
>> Poly1305DigestBench.digest       16384              thrpt    8    48762.991 ±    390.921  ops/s
>> Poly1305DigestBench.digest     1048576              thrpt    8      769.872 ±      1.402  ops/s
>> 
>> and after:
>> 
>> Benchmark                   (dataSize)  (provider)   Mode  Cnt        Score        Error  Units
>> Poly1305DigestBench.digest          64              thrpt    8  2841243.668 ± 154528.057  ops/s
>> Poly1305DigestBench.digest         256              thrpt    8  1662003.873 ±  95253.445  ops/s
>> Poly1305DigestBench.digest        1024              thrpt    8  1770028.718 ± 100847.766  ops/s
>> Poly1305DigestBench.digest       16384              thrpt    8   765547.287 ±  25883.825  ops/s
>> Poly1305DigestBench.digest     1048576              thrpt    8    14508.458 ±     56.147  ops/s
>
> Volodymyr Paprotski has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 12 commits:
> 
>  - Merge remote-tracking branch 'origin/master' into avx512-poly
>  - address Jamil's review
>  - invalidkeyexception and some review comments
>  - extra whitespace character
>  - assembler checks and test case fixes
>  - Merge remote-tracking branch 'origin/master' into avx512-poly
>  - Merge remote-tracking branch 'origin' into avx512-poly
>  - further restrict UsePolyIntrinsics with supports_avx512vlbw
>  - missed white-space fix
>  - - Fix whitespace and copyright statements
>    - Add benchmark
>  - ... and 2 more: https://git.openjdk.org/jdk/compare/9d3b4ef2...38d9e83c

Regarding the updated numbers and master v. optimized-and-disabled, those are looking pretty good.  Looks like the break-even point is at 64 bytes and gets better from there which I think addresses my concerns.

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PR: https://git.openjdk.org/jdk/pull/10582