Re: RFR: 8300208: Optimize Adler32 stub for AVX-512 targets.

[Vladimir Kozlov]

On Tue, 17 Jan 2023 17:24:20 GMT, Jatin Bhateja <jbhat...@openjdk.org> wrote:

> Patch optimizes Adler32 stub for AVX512 target.
> 
> Main computation loop now uses zero extended lane widening load vector 
> operation.
> 
> New sequence also honors AVX3Thresholds so that implementation uses existing 
> AVX2 instruction sequence on relevant targets
> if input size is smaller than threshold limit (default 4096).
> 
> Following are the result of an [existing JMH micro 
> ](https://github.com/openjdk/jdk/blob/master/test/micro/org/openjdk/bench/java/util/TestAdler32.java)on
>  various targets.
> 
> **System Configurations : Turbo frequency scaling is disabled, all the data 
> is collected at fixed frequency of 2.8 GHz.
> SUT1   : Intel® Xeon® Platinum 8480+ Processor (Sapphire Rapids)  56C 2S
> SUT2   : Intel(R) Xeon(R) Platinum 8380 CPU (Icelake Server) 40C 2S
> SUT3   : Intel(R) Xeon(R) Platinum 8280 CPU (Cascadelake Server) 28C 2S**
> 
> 
> ![image](https://user-images.githubusercontent.com/59989778/212934730-68717a61-191f-4dba-8c83-2eddf6007a47.png)
> 
> ![image](https://user-images.githubusercontent.com/59989778/212934945-cada95ad-c93c-487f-bacc-928a2e3b5c21.png)
> 
> ![image](https://user-images.githubusercontent.com/59989778/212935059-511aca3b-c736-40a2-bff6-89caf0664828.png)
> 
> 
> Please review and share your feedback.
> 
> Best Regards,
> Jatin

Looks good to me. Let me test it.

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

PR: https://git.openjdk.org/jdk/pull/12045