8335390: C2 MergeStores: wrong result with Unsafe

[eme64]

In JDK23, I introduced MergeStores JDK-8318446 #16245.

I now realized that the pointer-parsing has some issues with Unsafe stores. Thus, I disable the optimization for those for now.

Future Work
In JDK-8335392, I plan to redesign the pointer-parsing, and enable more features, including Unsafe stores.

---

Progress

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• Commit message must refer to an issue

Issue

• JDK-8335390: C2 MergeStores: wrong result with Unsafe (Bug - P2)

Reviewers

• Tobias Hartmann (@TobiHartmann - Reviewer) ⚠️ Review applies to ec5cc941
• Christian Hagedorn (@chhagedorn - Reviewer)
• Vladimir Kozlov (@vnkozlov - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/19964/head:pull/19964
$ git checkout pull/19964

Update a local copy of the PR:
$ git checkout pull/19964
$ git pull https://git.openjdk.org/jdk.git pull/19964/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 19964

View PR using the GUI difftool:
$ git pr show -t 19964

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/19964.diff

Webrev

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[bridgekeeper]

👋 Welcome back epeter! 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]

@eme64 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:

8335390: C2 MergeStores: wrong result with Unsafe

Reviewed-by: thartmann, chagedorn, kvn

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 192 new commits pushed to the master branch:

• 2f4f6cc: 8317721: RISC-V: Implement CRC32 intrinsic
• 3ca2bcd: 8335060: ClassCastException after JDK-8294960
• 747e1e4: 8334295: CTW: update modules
• 0a6ffa5: 8261242: [Linux] OSContainer::is_containerized() returns true when run outside a container
• 71e3798: 8335308: compiler/uncommontrap/DeoptReallocFailure.java times out with SerialGC on Windows
• c7e9ebb: 8331732: [PPC64] Unify and optimize code which converts != 0 to 1
• 53242cd: 8335283: Build failure due to 'no_sanitize' attribute directive ignored
• d9bcf06: 8335217: Fix memory ordering in ClassLoaderData::ChunkedHandleList
• bb18498: 8335349: jcmd VM.classloaders "fold" option should be optional
• 8350b1d: 8335294: Fix simple -Wzero-as-null-pointer-constant warnings in gc code
• ... and 182 more: https://git.openjdk.org/jdk/compare/b09a45163ccc566b4f7653c2e9030e359396c90f...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.

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

[openjdk]

@eme64 The following label will be automatically applied to this pull request:

• hotspot-compiler

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[TobiHartmann]

Looks good to me.

[mlbridge]

Webrevs

• 01: Full - Incremental (c9477f89)
• 00: Full (d327e186)

[chhagedorn]

Looks good to me, too.

[vnkozlov]

Good.

[eme64]

Thanks @vnkozlov @TobiHartmann @chhagedorn for the reviews!
/integrate

[openjdk]

Going to push as commit 9046d7a.
Since your change was applied there have been 195 commits pushed to the master branch:

• 318d9ac: 8335369: Fix -Wzero-as-null-pointer-constant warnings in ImmutableOopMapBuilder
• 5fe07b3: 5021949: JSplitPane setEnabled(false) shouldn't be partially functional
• ee4720a: 8333306: gc/arguments/TestParallelGCErgo.java fails when largepage are enabled
• 2f4f6cc: 8317721: RISC-V: Implement CRC32 intrinsic
• 3ca2bcd: 8335060: ClassCastException after JDK-8294960
• 747e1e4: 8334295: CTW: update modules
• 0a6ffa5: 8261242: [Linux] OSContainer::is_containerized() returns true when run outside a container
• 71e3798: 8335308: compiler/uncommontrap/DeoptReallocFailure.java times out with SerialGC on Windows
• c7e9ebb: 8331732: [PPC64] Unify and optimize code which converts != 0 to 1
• 53242cd: 8335283: Build failure due to 'no_sanitize' attribute directive ignored
• ... and 185 more: https://git.openjdk.org/jdk/compare/b09a45163ccc566b4f7653c2e9030e359396c90f...master

Your commit was automatically rebased without conflicts.

[openjdk]

@eme64 Pushed as commit 9046d7a.

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

[eme64]

/backport jdk:jdk23

[openjdk]

@eme64 the backport was successfully created on the branch backport-eme64-9046d7ae-jdk23 in my personal fork of openjdk/jdk. To create a pull request with this backport targeting openjdk/jdk:jdk23, just click the following link:

➡️ Create pull request

The title of the pull request is automatically filled in correctly and below you find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit 9046d7ae from the openjdk/jdk repository.

The commit being backported was authored by Emanuel Peter on 2 Jul 2024 and was reviewed by Tobias Hartmann, Christian Hagedorn and Vladimir Kozlov.

Thanks!

If you need to update the source branch of the pull then run the following commands in a local clone of your personal fork of openjdk/jdk:

$ git fetch https://github.com/openjdk-bots/jdk.git backport-eme64-9046d7ae-jdk23:backport-eme64-9046d7ae-jdk23
$ git checkout backport-eme64-9046d7ae-jdk23
# make changes
$ git add paths/to/changed/files
$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk.git backport-eme64-9046d7ae-jdk23

⚠️ @eme64 You are not yet a collaborator in my fork openjdk-bots/jdk. An invite will be sent out and you need to accept it before you can proceed.