8354348: Enable Extended EVEX to REX2/REX demotion for commutative operations with same dst and src2

[vamsi-parasa]

Hi all,

This pull request contains a backport of commit c41add8d from the openjdk/jdk repository.

The commit being backported was authored by Srinivas Vamsi Parasa on 16 Sep 2025 and was reviewed by Jatin Bhateja, Emanuel Peter and Sandhya Viswanathan.

Thanks!

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8354348 needs maintainer approval

Issue

• JDK-8354348: Enable Extended EVEX to REX2/REX demotion for commutative operations with same dst and src2 (Sub-task - P4 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk25u.git pull/328/head:pull/328
$ git checkout pull/328

Update a local copy of the PR:
$ git checkout pull/328
$ git pull https://git.openjdk.org/jdk25u.git pull/328/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 328

View PR using the GUI difftool:
$ git pr show -t 328

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk25u/pull/328.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back sparasa! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@vamsi-parasa This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8354348: Enable Extended EVEX to REX2/REX demotion for commutative operations with same dst and src2

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 24 new commits pushed to the master branch:

• f597463: Merge
• 78770bf: 8367031: [backout] Change java.time month/day field types to 'byte'
• 5100536: 8368308: ISO 4217 Amendment 180 Update
• ... and 21 more: https://git.openjdk.org/jdk25u/compare/cd99e8febdebc904c2737ceac427960ee5ac48a2...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 00: Full (1ed38ac5)

[vamsi-parasa]

/integrate

[openjdk]

@vamsi-parasa
Your change (at version 1ed38ac) is now ready to be sponsored by a Committer.

[phohensee]

/sponsor

[openjdk]

Going to push as commit 8f284e3.
Since your change was applied there have been 34 commits pushed to the master branch:

• ceac6c7: 8359735: [Ubuntu 25.10] java/lang/ProcessBuilder/Basic.java, java/lang/ProcessHandle/InfoTest.java fail due to rust-coreutils
• f98bbdf: 8367904: Test java/net/InetAddress/ptr/Lookup.java should throw SkippedException
• 5228b25: 8370049: [s390x] G1 barrier compareAndExchange does not return old value when compareExchange fails
• ... and 31 more: https://git.openjdk.org/jdk25u/compare/cd99e8febdebc904c2737ceac427960ee5ac48a2...master

Your commit was automatically rebased without conflicts.

[openjdk]

@phohensee @vamsi-parasa Pushed as commit 8f284e3.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.