8316679: C2 SuperWord: wrong result, load should not be moved before store if not comparable

[shipilev]

Unclean backport to fix the vectorization bug. The patch is unclean because JDK 21u does not have JDK-8312332 refactoring, that I do not want to backport. I have reapplied the patch by renaming SWPointer again.

Note @eme64, @TobiHartmann.

Additional testing:

• MacOS AArch64 Server fastdebug, new regression test fails without the patch, passes with it
• MacOS AArch64 Server fastdebug, compiler/loopopts
• Linux x86_64 server fastdebug, tier1 tier2 tier3 tier4

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8316679 needs maintainer approval

Issue

• JDK-8316679: C2 SuperWord: wrong result, load should not be moved before store if not comparable (Bug - P3 - Approved)

Reviewers

• Emanuel Peter (@eme64 - no project role)
• Paul Hohensee (@phohensee - Reviewer)
• Tobias Hartmann (@TobiHartmann - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u.git pull/327/head:pull/327
$ git checkout pull/327

Update a local copy of the PR:
$ git checkout pull/327
$ git pull https://git.openjdk.org/jdk21u.git pull/327/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 327

View PR using the GUI difftool:
$ git pr show -t 327

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u/pull/327.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back shade! 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.

[mlbridge]

Webrevs

• 00: Full (dd330cc9)

[eme64]

Looks reasonable. Renaming VPointer -> SWPointer is required.

[shipilev]

/approval request Unclean backport to fix the vectorization bug. The patch is unclean because JDK 21u does not have JDK-8312332 refactoring, that I do not want to backport. JDK 21u PR is acked by Emanuel Peter.

[openjdk]

@shipilev
8316679: The approval request has been created successfully.

[shipilev]

/integrate

[openjdk]

@shipilev This pull request has not yet been marked as ready for integration.

[shipilev]

Dang, I need a formal (R)eviewer for this. @phohensee?

[openjdk]

⚠️ @shipilev 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.

[openjdk]

@shipilev 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:

8316679: C2 SuperWord: wrong result, load should not be moved before store if not comparable

Reviewed-by: epeter, phh, thartmann

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 15 new commits pushed to the master branch:

• 0e2a520: 8318951: Additional negative value check in JPEG decoding
• 0679922: 8294535: Add screen capture functionality to PassFailJFrame
• 7f02e4a: 8301846: Invalid TargetDataLine after screen lock when using JFileChooser or COM library
• 6632c8a: 8317374: Add Let's Encrypt ISRG Root X2
• 243142c: 8314580: PhaseIdealLoop::transform_long_range_checks fails with assert "was tested before"
• b93d884: 8318183: C2: VM may crash after hitting node limit
• fb355df: 8309209: C2 failed "assert(_stack_guard_state == stack_guard_reserved_disabled) failed: inconsistent state"
• 50c34ca: 8316645: RISC-V: Remove dependency on libatomic by adding cmpxchg 1b
• eb8267d: 8316585: [REDO] runtime/InvocationTests spend a lot of time on dependency verification
• 31c759d: 8315362: NMT: summary diff reports threads count incorrectly
• ... and 5 more: https://git.openjdk.org/jdk21u/compare/4bbea6dde3a3b6bf07e515adb3cf7d1b22bfec91...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.

[TobiHartmann]

Looks good.

[shipilev]

Thank you all!

/integrate

[openjdk]

Going to push as commit 9008889.
Since your change was applied there have been 15 commits pushed to the master branch:

• 0e2a520: 8318951: Additional negative value check in JPEG decoding
• 0679922: 8294535: Add screen capture functionality to PassFailJFrame
• 7f02e4a: 8301846: Invalid TargetDataLine after screen lock when using JFileChooser or COM library
• 6632c8a: 8317374: Add Let's Encrypt ISRG Root X2
• 243142c: 8314580: PhaseIdealLoop::transform_long_range_checks fails with assert "was tested before"
• b93d884: 8318183: C2: VM may crash after hitting node limit
• fb355df: 8309209: C2 failed "assert(_stack_guard_state == stack_guard_reserved_disabled) failed: inconsistent state"
• 50c34ca: 8316645: RISC-V: Remove dependency on libatomic by adding cmpxchg 1b
• eb8267d: 8316585: [REDO] runtime/InvocationTests spend a lot of time on dependency verification
• 31c759d: 8315362: NMT: summary diff reports threads count incorrectly
• ... and 5 more: https://git.openjdk.org/jdk21u/compare/4bbea6dde3a3b6bf07e515adb3cf7d1b22bfec91...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 9008889.

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