RFR: 8341013: Optimize x86/aarch64 MD5 intrinsics by reducing data dependency [v2]
Anthony Scarpino
ascarpino at openjdk.org
Sat Sep 28 17:56:35 UTC 2024
On Thu, 26 Sep 2024 14:58:49 GMT, Oli Gillespie <ogillespie at openjdk.org> wrote:
>> As suggested in https://github.com/animetosho/md5-optimisation?tab=readme-ov-file#dependency-shortcut-in-g-function, we can delay the dependency on 'b' by recognizing that the ((d & b) | (~d & c)) is equivalent to ((d & b) + (~d & c)) in this scenario, and we can perform those additions independently, leaving our dependency on b to the final addition. This speeds it up around 5%.
>>
>> Benchmark results on my two hosts:
>>
>>
>> Benchmark (algorithm) (dataSize) (provider) Mode Cnt Score Error Units
>>
>> x86 Before:
>> MessageDigestBench.digest MD5 1048576 thrpt 10 636.389 ± 0.240 ops/s
>>
>> x86 After:
>> MessageDigestBench.digest MD5 1048576 thrpt 10 671.611 ± 0.226 ops/s (+5.5%)
>>
>>
>> aarch64 Before:
>> MessageDigestBench.digest MD5 1048576 thrpt 10 498.613 ± 0.359 ops/s
>>
>> aarch64 After:
>> MessageDigestBench.digest MD5 1048576 thrpt 10 526.008 ± 0.491 ops/s (+5.6%)
>
> Oli Gillespie has updated the pull request incrementally with one additional commit since the last revision:
>
> Fix aarch64 bug
The changes look good and they passed the tier 1-3 testing
-------------
Marked as reviewed by ascarpino (Reviewer).
PR Review: https://git.openjdk.org/jdk/pull/21203#pullrequestreview-2335385133
More information about the hotspot-dev
mailing list