8320807: [PPC64][ZGC] C1 generates wrong code for atomics

[TheRealMDoerr]

Backport of JDK-8320807.

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Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8320807 needs maintainer approval

Issue

• JDK-8320807: [PPC64][ZGC] C1 generates wrong code for atomics (Bug - P3 - Approved)

Reviewing

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/4/head:pull/4
$ git checkout pull/4

Update a local copy of the PR:
$ git checkout pull/4
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/4/head

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Checkout this PR locally:
$ git pr checkout 4

View PR using the GUI difftool:
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[bridgekeeper]

👋 Welcome back mdoerr! 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]

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

[openjdk]

⚠️ @TheRealMDoerr This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[mlbridge]

Webrevs

• 00: Full (3e5ef2ad)

[TheRealMDoerr]

/approval request JDK21 is affected by this Generational ZGC bug. Fix applies cleanly and has been tested for 2 weeks in head. Retested in JDK21u-dev. Only touches PPC64 files.

[TheRealMDoerr]

Pre-submit test failures are unrelated. This PR only touches PPC64 files.

[openjdk]

@TheRealMDoerr
8320807: The approval request has been created successfully.

[openjdk]

@TheRealMDoerr 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:

8320807: [PPC64][ZGC] C1 generates wrong code for atomics

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At the time when this comment was updated there had been 1 new commit pushed to the master branch:

• fb34573: 8321894: Bump update version for OpenJDK: 21.0.3

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

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[TheRealMDoerr]

/integrate

[openjdk]

Going to push as commit 0106db0.
Since your change was applied there have been 2 commits pushed to the master branch:

• 0e0e897: 8320898: exclude compiler/vectorapi/reshape/TestVectorReinterpret.java on ppc64(le) platforms
• fb34573: 8321894: Bump update version for OpenJDK: 21.0.3

Your commit was automatically rebased without conflicts.

[openjdk]

@TheRealMDoerr Pushed as commit 0106db0.

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