RFR: 8351016: RA support for EVEX to REX/REX2 demotion to optimize NDD instructions [v8]

[Jatin Bhateja]

On Wed, 29 Oct 2025 21:29:08 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Removing redundant interferecne check from biasing
>
> Hard-coded lists in `Matcher::should_attempt_register_biasing()` and `is_commutative_oper` look fragile and hard to verify.  (Especially `is_commutative_oper` which is used to check the root of matched ideal tree.)  
> 
> With proper ADLC support, that information can be placed on individual AD instructions which would make it clearer what is affected.

Hi @iwanowww , @dlunde , @eme64 , @TobiHartmann , @sviswa7 , your comments have been addressed.
Let me know if this is good to land in.

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PR Comment: https://git.openjdk.org/jdk/pull/26283#issuecomment-3540284439