8322996: BoxLockNode creation fails with assert(reg < CHUNK_SIZE) failed: sanity

[dlunde]

This changeset fixes an issue where deeply nested synchronized statements triggered an assert in C2.

Changes:

• Bail out on compilation when we create a BoxLockNode with a slot index that cannot fit in a RegMask. This is similar to how we handle the case when we do not have space to represent arguments in opto/matcher.cpp
• Generalize RegMask::can_represent to take an additional and optional size argument to facilitate reuse. The default size value, 1, corresponds to the previous functionality. Rewrite can_represent_arg to directly call can_represent(reg, SlotsPerVecZ).
• Add a regression test.

Testing:

• GitHub Actions
• tier1 to tier5 on windows-x64, linux-x64, linux-aarch64, macosx-x64, and macosx-aarch64.
• The new regression test in all tier1 to tier10 contexts on windows-x64, linux-x64, linux-aarch64, macosx-x64, and macosx-aarch64.

---

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

Issue

• JDK-8322996: BoxLockNode creation fails with assert(reg < CHUNK_SIZE) failed: sanity (Bug - P3)

Reviewers

• Roberto Castañeda Lozano (@robcasloz - Reviewer) ⚠️ Review applies to 524438ca
• Vladimir Kozlov (@vnkozlov - Reviewer) ⚠️ Review applies to ebe23a23

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[bridgekeeper]

👋 Welcome back dlunden! 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]

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

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[mlbridge]

Webrevs

• 07: Full - Incremental (8100a3e5)
• 06: Full - Incremental (ebe23a23)
• 05: Full - Incremental (5fedbc3b)
• 04: Full - Incremental (524438ca)
• 03: Full - Incremental (bf87138f)
• 02: Full - Incremental (9ab6e561)
• 01: Full - Incremental (735543d0)
• 00: Full (06d6b4be)

[dlunde]

@robcasloz @vnkozlov: I have now made the changes we've discussed. Please have a look when you have some time to spare.

[robcasloz]

The fix itself looks good to me.
Would it make sense, for better coverage, to add a couple of additional test cases that exercise the boundaries of the condition that is tested? E.g. one with one synchronized statement less than the current one and one with one synchronized statement more.

[dlunde]

The fix itself looks good to me. Would it make sense, for better coverage, to add a couple of additional test cases that exercise the boundaries of the condition that is tested? E.g. one with one synchronized statement less than the current one and one with one synchronized statement more.

I have experimented with such test cases (various edge cases) and as a result found a related (but separate) issue from this one. I was planning to add these additional tests for that separate issue, to not introduce unnecessary test failures before that fix is integrated. Maybe it is better to add the additional tests directly as part of this changeset instead?

[robcasloz]

I have experimented with such test cases (various edge cases) and as a result found a related (but separate) issue from this one. I was planning to add these additional tests for that separate issue, to not introduce unnecessary test failures before that fix is integrated. Maybe it is better to add the additional tests directly as part of this changeset instead?

If the additional tests trigger failures after this fix is applied, I would suggest including them as part of the fix to the separate issue.

[openjdk]

@dlunde 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:

8322996: BoxLockNode creation fails with assert(reg < CHUNK_SIZE) failed: sanity

Reviewed-by: rcastanedalo, 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 209 new commits pushed to the master branch:

• f0bae79: 8324750: C2: rename Matcher methods using "superword" -> "autovectorization"
• 6ad78ca: 8324775: C2 SuperWord: refactor visited sets
• 422020c: 8210858: AArch64: remove Math.log intrinsic
• 0d5f5e1: 8322484: 22-b26 Regression in J2dBench-bimg_misc-G1 (and more) on Windows-x64 and macOS-x64
• af9cd97: 8324800: gcc windows build broken after 8322757
• 8950d68: 8324753: [AIX] adjust os_posix after JDK-8318696
• 65d6bc1: 8324765: C2 SuperWord: remove dead code: SuperWord::insert_extracts
• 525c0cd: 8324752: C2 Superword: remove SuperWordRTDepCheck
• 2e748c9: 8175386: Clarify exception behavior of Types utility methods
• 70f4a4e: 8324786: validate-source fails after JDK-8042981
• ... and 199 more: https://git.openjdk.org/jdk/compare/b922f8d45951250b7c39cb179b9bc1a8a6256a9e...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. Possible candidates are the reviewers of this PR (@robcasloz, @vnkozlov) but any other Committer may sponsor as well.

➡️ 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).

[vnkozlov]

Looks good. I have one question.

[vnkozlov]

Looks good.

[dlunde]

Thanks @robcasloz and @vnkozlov. I've now rerun tests and the PR is ready for integration. Please sponsor!

/integrate

[openjdk]

@dlunde
Your change (at version 8100a3e) is now ready to be sponsored by a Committer.

[robcasloz]

/sponsor

[openjdk]

Going to push as commit 69586e7.
Since your change was applied there have been 209 commits pushed to the master branch:

• f0bae79: 8324750: C2: rename Matcher methods using "superword" -> "autovectorization"
• 6ad78ca: 8324775: C2 SuperWord: refactor visited sets
• 422020c: 8210858: AArch64: remove Math.log intrinsic
• 0d5f5e1: 8322484: 22-b26 Regression in J2dBench-bimg_misc-G1 (and more) on Windows-x64 and macOS-x64
• af9cd97: 8324800: gcc windows build broken after 8322757
• 8950d68: 8324753: [AIX] adjust os_posix after JDK-8318696
• 65d6bc1: 8324765: C2 SuperWord: remove dead code: SuperWord::insert_extracts
• 525c0cd: 8324752: C2 Superword: remove SuperWordRTDepCheck
• 2e748c9: 8175386: Clarify exception behavior of Types utility methods
• 70f4a4e: 8324786: validate-source fails after JDK-8042981
• ... and 199 more: https://git.openjdk.org/jdk/compare/b922f8d45951250b7c39cb179b9bc1a8a6256a9e...master

Your commit was automatically rebased without conflicts.

[openjdk]

@robcasloz @dlunde Pushed as commit 69586e7.

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