8378523: [lworld] Remove post-barriers from CardTableBarrierSet value_store_null_in_heap

[xmas92]

Remove the post barriers when clearing a flat field / element. All contained oops will be null, no cards need to be dirtied.

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Progress

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Issue

• JDK-8378523: [lworld] Remove post-barriers from CardTableBarrierSet value_store_null_in_heap (Enhancement - P4)

Reviewers

• Stefan Karlsson (@stefank - Committer)

Reviewing

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[bridgekeeper]

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

[openjdk]

@xmas92 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:

8378523: [lworld] Remove post-barriers from CardTableBarrierSet value_store_null_in_heap

Reviewed-by: stefank

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 128 new commits pushed to the lworld branch:

• a2f9166: 8379007: [lworld] JNI NewWeakGlobalRef should throw IdentityException for value types
• 9c53e9a: 8378184: [lworld] JDK - Cleanup accidental diffs with master - step 1
• b558a7b: 8379164: [lworld] Handle reflective preview API use in jdk.jdeps
• ... and 125 more: https://git.openjdk.org/valhalla/compare/f321813503a1c58f83b382fbbf2f21a1f92a9239...lworld

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.

➡️ To integrate this PR with the above commit message to the lworld branch, type /integrate in a new comment.

[mlbridge]

Webrevs

• 00: Full (2cc85c8b)

[xmas92]

Thanks for the review.
/integrate

[openjdk]

Going to push as commit 677ef96.
Since your change was applied there have been 131 commits pushed to the lworld branch:

• aa826cb: 8379406: [lworld] Specify the behavior of the instance returned by allocateInstance
• 6fe4e17: 8335187: [lworld] add a comment to Object::finalize stating that it is not supported for value classes
• 4b6a580: 8379328: [lworld] [BACKOUT] JNI NewWeakGlobalRef should throw IdentityException for value types
• ... and 128 more: https://git.openjdk.org/valhalla/compare/f321813503a1c58f83b382fbbf2f21a1f92a9239...lworld

Your commit was automatically rebased without conflicts.

[openjdk]

@xmas92 Pushed as commit 677ef96.

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