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

[Daniel Lundén]

On Mon, 17 Nov 2025 07:11:40 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> 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.

Thanks for the updates @jatin-bhateja, looks good to me. I'm rerunning some tests for sanity before I click approve!

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PR Comment: https://git.openjdk.org/jdk/pull/26283#issuecomment-3542190601