RFR: 8351016: RA support for EVEX to REX/REX2 demotion to optimize NDD instructions [v10]

Wed Nov 12 18:11:38 UTC 2025

On Wed, 12 Nov 2025 15:57:25 GMT, Daniel Lundén <dlunden at openjdk.org> wrote:

> I am convinced your patch provides improvements in many cases. What I'm worried about is regressions. Do I understand you correctly: the patch provides, in theory, strict code size improvements without any other disadvantages? My performance testing (DaCapo 23, SPECjbb 2005, and SPECjvm 2008) indicates no regressions, so that's good.
> 
Yes, patch biases the def operands towards non-interfearing first or second operand LRGs, and should facilate NDD demotion.
Glad to know that there are no side effect seen with benchmarks!!, suggestions incorporated!.

Best Regards

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PR Comment: https://git.openjdk.org/jdk/pull/26283#issuecomment-3523246859