[vectorIntrinsics] RFR: 8283413: Add C2 mid-end and x86 back-end implementation for bit REVERSE and REVERSE_BYTES operation [v6]

[Eric Liu]

On Wed, 6 Apr 2022 18:54:44 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> Hi All,
>> 
>> Patch includes following changes:-
>> - New C2 IR nodes to support VectorOperations.REVERSE operation.
>> - X86 backend implementation for targets supporting AVX2, AVX512 and GFNI features.
>> 
>> Please find below the performance data of Vector API JMH micros:-
>> 
>> System Configuration:
>> ICX: Intel(R) Xeon(R) Platinum 8380 CPU @ 2.30GHz (40C 2S)
>> CLX: Intel(R) Xeon(R) Platinum 8280 CPU @ 2.70GHz (28C 2S)
>> 
>> ![image](https://user-images.githubusercontent.com/59989778/159196997-fd1ae2ad-37ee-4294-9928-5764707bb456.png)
>> 
>> 
>> 
>> Kindly review and share your feedback.
>> 
>> Regards,
>> Jatin
>
> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8283413: Review comments resolution.

LGTM.

src/hotspot/share/opto/vectornode.hpp line 1703:

> 1701: 
> 1702:   virtual int Opcode() const;
> 1703: };

Just a little tip: Can we add Identify for BYTE type, that is ReverseBytesV(x) ->x.

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Marked as reviewed by eliu (Committer).

PR: https://git.openjdk.java.net/panama-vector/pull/182