RFR: 8305783: x86_64: Optimize AbsI and AbsL [v2]

[Quan Anh Mai]

On Mon, 10 Apr 2023 02:53:25 GMT, Jasmine Karthikeyan <jkarthikeyan at openjdk.org> wrote:

>> Quan Anh Mai has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - description
>>  - description
>
> Patch looks nice! (I am not a reviewer.) I have one comment with the code.
> 
> I was also thinking that the unconditional usage of cmov here may lead to performance issues if the abs is part of a loop-carried dependency, as I've seen that happen before with MinI/MaxI nodes before. I did a [small test](https://gist.github.com/jaskarth/d502adfe3a0e82c30b885ce660262161) to see if that was the case here and it seems there's no regression, so very nice!

@jaskarth Thanks a lot for your review, I think this cannot introduce more dependency into the operation since it depends on `src` already. I also added more description to the `format` sections

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PR Comment: https://git.openjdk.org/jdk/pull/13402#issuecomment-1501794690