8314580: PhaseIdealLoop::transform_long_range_checks fails with assert "was tested before"

[shipilev]

Clean backport to improve C2 stability.

Additional testing:

• New regression test fails without fix, passes with it
• Linux AArch64 server fastdebug, tier1 tier2 tier3

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8314580 needs maintainer approval

Issue

• JDK-8314580: PhaseIdealLoop::transform_long_range_checks fails with assert "was tested before" (Bug - P3 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u.git pull/316/head:pull/316
$ git checkout pull/316

Update a local copy of the PR:
$ git checkout pull/316
$ git pull https://git.openjdk.org/jdk21u.git pull/316/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 316

View PR using the GUI difftool:
$ git pr show -t 316

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u/pull/316.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.

[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.

[mlbridge]

Webrevs

• 00: Full (67729d1d)

[shipilev]

/approval request Clean backport to improve C2 stability. Applies cleanly. Testing passed.

[openjdk]

@shipilev
8314580: The approval request has been created successfully.

[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:

8314580: PhaseIdealLoop::transform_long_range_checks fails with assert "was tested before"

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 19 new commits pushed to the master branch:

• 421bf8a: 8316461: Fix: make test outputs TEST SUCCESS after unsuccessful exit
• 337271f: 8317920: JDWP-agent sends broken exception event with onthrow option
• 4cf572e: 8316304: (fs) Add support for BasicFileAttributes.creationTime() for Linux
• 4bbea6d: 8315415: OutputAnalyzer.shouldMatchByLine() fails in some cases
• 4a6c0d8: 8314242: Update applications/scimark/Scimark.java to accept VM flags
• 504f4a0: 8286757: adlc tries to build with /pathmap but without /experimental:deterministic
• e2b89c7: 8316648: jrt-fs.jar classes not reproducible between standard and bootcycle builds
• 892938d: 8312434: SPECjvm2008/xml.transform with CDS fails with "can't seal package nu.xom"
• 844c32a: 8316142: Enable parallelism in vmTestbase/nsk/monitoring/stress/lowmem tests
• 3552d5a: 8316659: assert(LockingMode != LM_LIGHTWEIGHT || flag == CCR0) failed: bad condition register
• ... and 9 more: https://git.openjdk.org/jdk21u/compare/de57df40bfc480627e6b8c639ac06150adb89a88...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.

[shipilev]

/integrate

[openjdk]

Going to push as commit 243142c.
Since your change was applied there have been 26 commits pushed to the master branch:

• 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
• 6bd2c5a: 8318474: Fix memory reporter for thread_count
• 7091631: 8319525: RISC-V: Rename *_riscv64.ad files to *_riscv.ad under riscv/gc
• 421bf8a: 8316461: Fix: make test outputs TEST SUCCESS after unsuccessful exit
• 337271f: 8317920: JDWP-agent sends broken exception event with onthrow option
• 4cf572e: 8316304: (fs) Add support for BasicFileAttributes.creationTime() for Linux
• ... and 16 more: https://git.openjdk.org/jdk21u/compare/de57df40bfc480627e6b8c639ac06150adb89a88...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 243142c.

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