RFR: 8288047: Accelerate Poly1305 on x86_64 using AVX512 instructions [v16]

[Vladimir Ivanov]

On Mon, 14 Nov 2022 17:58:36 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 23 commits:
> 
>  - Merge remote-tracking branch 'origin/master' into avx512-poly
>  - Vladimir's review
>  - live review with Sandhya
>  - jcheck
>  - Sandhya's review
>  - fix windows and 32b linux builds
>  - add getLimbs to interface and reviews
>  - fix 32-bit build
>  - make UsePolyIntrinsics option diagnostic
>  - Merge remote-tracking branch 'origin/master' into avx512-poly
>  - ... and 13 more: https://git.openjdk.org/jdk/compare/e269dc03...a26ac7db

src/hotspot/cpu/x86/stubGenerator_x86_64_poly.cpp line 370:

> 368:   // Middle 44-bit limbs of new blocks
> 369:   __ vpsrlq(L1, L0, 44, Assembler::AVX_512bit);
> 370:   __ vpsllq(TMP2, TMP1, 20, Assembler::AVX_512bit);

Any particular reason to use `TMP2` here? Can you just update `TMP1` instead (w/ `vpsllq(TMP1, TMP1, 20, Assembler::AVX_512bit);`)?

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

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