RFR: 8359965: Enable paired pushp and popp instruction usage for APX enabled CPUs [v2]

Mon Jul 21 17:34:37 UTC 2025

On Mon, 21 Jul 2025 17:23:15 GMT, Srinivas Vamsi Parasa <sparasa at openjdk.org> wrote:

>> Hi @vamsi-parasa , I think it's ok not to expose pop_ppx / push_ppx as separate interfaces, and let processor forward the values b/w push and matching pop if balancing constraints are satisfied.
>> 
>> <img width="1055" height="151" alt="image" src="https://github.com/user-attachments/assets/6923ca1b-11eb-4fae-8d51-14f1bfe27cea" />
>
> Hi Jatin (@jatin-bhateja), the reason to make the push_ppx/pop_ppx usage explicit is because an unbalanced push_ppx operation has a performance penalty.

> Please create a new RFE for its tracking.

Hi Jatin(@jatin-bhateja) , please see the JBS issue (https://bugs.openjdk.org/browse/JDK-8362903) for push2/pop2 enabling in future.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25889#discussion_r2219828160