RFR: 8282162: [vector] Optimize vector negation API [v2]

[Xiaohong Gong]

On Mon, 28 Mar 2022 07:40:48 GMT, Jie Fu <jiefu at openjdk.org> wrote:

>> The compiler can get the real type info from `Op_NegVI` that can also handle the `BYTE ` and `SHORT ` basic type. I just don't want to add more new IRs which also need more match rules in the ad files.
>> 
>>> Is there any performance drop for byte/short negation operation if both of them are handled as a NegVI vector?
>> 
>> From the benchmark results I showed in the commit message, I didn't see not any performance drop for byte/short.  Thanks!
>
>> The compiler can get the real type info from `Op_NegVI` that can also handle the `BYTE ` and `SHORT ` basic type. I just don't want to add more new IRs which also need more match rules in the ad files.
>> 
>> > Is there any performance drop for byte/short negation operation if both of them are handled as a NegVI vector?
>> 
>> From the benchmark results I showed in the commit message, I didn't see not any performance drop for byte/short. Thanks!
> 
> There seems no vectorized negation instructions for {byte, short, int, long} on x86, so this should be fine on x86.
> I tested the patch on x86 and the performance number looks good.

Thanks for doing this! Yeah, I think the performance for masked negation operations might improve on non avx-512 systems.

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PR: https://git.openjdk.java.net/jdk/pull/7782