RFR: 8336860: x86: Change integer src operand for CMoveL of 0 and 1 to long [v4]

[Emanuel Peter]

On Fri, 30 Aug 2024 14:58:01 GMT, Jasmine Karthikeyan <jkarthikeyan at openjdk.org> wrote:

>> Hi all,
>> This patch fixes `cmovL_imm_01*` instructions matching against an integer immediate 1 instead of a long immediate 1. I noticed while looking at the backend implementation of CMove that the rules specify `immI_1` instead of `immL1`, which means that the instructions can't be matched and instead falls through to the base case. I added a small benchmark and got these results:
>> 
>>                                         Baseline                     Patch           Improvement
>> Benchmark                Mode  Cnt    Score   Error  Units      Score   Error  Units
>> BasicRules.cmovL_imm_01  avgt   15  259.073 ± 5.806  ns/op    231.108 ± 2.730  ns/op  (+ 11.41%)
>> 
>> Thoughts and reviews would be appreciated!
>
> Jasmine Karthikeyan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Move architecture checks into IR

I'm now good with it, but I'm away from my work laptop and cannot run our testing...

@chhagedorn @TobiHartmann Can one of you please run testing for this before it is integrated?

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Marked as reviewed by epeter (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20275#pullrequestreview-2277643723