8257574: C2: "failed: parsing found no loops but there are some" assert failure

[rwestrel]

The assert fires because the loop only has an infinite loop which
causes the has_loops flag to be cleared. But because a NeverBranch is
also added to the graph on the next pass of loop opts (for
verification), C2 finds a loop and that's inconsistent with the
has_loops flag. This is supposed to be handled by the
only_has_infinite_loops() call in the assert but not in this case
because the loop is not an innermost loop.

---

Progress

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Issue

• JDK-8257574: C2: "failed: parsing found no loops but there are some" assert failure

Reviewers

• Tobias Hartmann (@TobiHartmann - Reviewer)
• Nils Eliasson (@neliasso - Reviewer)
• Christian Hagedorn (@chhagedorn - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/1556/head:pull/1556
$ git checkout pull/1556

[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (e197392)

[TobiHartmann]

Looks good to me.

[openjdk]

@rwestrel 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:

8257574: C2: "failed: parsing found no loops but there are some" assert failure

Reviewed-by: thartmann, neliasso, chagedorn

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 74 new commits pushed to the master branch:

• af6b7f9: 8257743: Minimal build on AArch64 failed with --disable-precompiled-headers
• d6dd440: 8256264: Printed GlyphVector outline with low DPI has bad quality on Windows
• 2b4a423: 8255542: Attribute length of Module, ModulePackages and other attributes is ignored
• ca40267: 8257509: Strengthen requirements to call G1HeapVerifier::verify(VerifyOption)
• 4a85514: 8257182: JCK test failures in integer / long rotation tests
• f33808f: 8257631: C2: Assertion failure in ArrayCopyNode::get_count() during late inlining
• 417e7e6: 8257632: C2: Late inlining attempt on a call with a dead memory crashes
• 6845fee: 8257625: C2: Harden input checks in vector intrinsics
• 4390f2c: 8257630: C2: ReplacedNodes doesn't handle non-CFG multi nodes
• d08c612: 8257708: Remove redundant unmodifiableSet wrapper from already immutable set returned by Collections.singleton
• ... and 64 more: https://git.openjdk.java.net/jdk/compare/eaf4db6b8b883b1ab5731ac62f590e39a7b67210...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.

[neliasso]

Looks good.

[chhagedorn]

Looks good to me.

[rwestrel]

@TobiHartmann @neliasso @chhagedorn thanks for the reviews

[rwestrel]

/integrate

[openjdk]

@rwestrel Since your change was applied there have been 80 commits pushed to the master branch:

• dede01e: 8257622: MemoryAccess methods are missing @forceinline annotations
• 1d2d981: 8257423: [PPC64] Support -XX:-UseInlineCaches
• feabdde: 8251843: jfr/tool/TestPrintJSON.java fails intermittently
• c6f93ec: 8257707: Fix incorrect format string in Http1HeaderParser
• fbdc187: 8257624: C2: PhaseMacroExpand::eliminate_macro_nodes() crashes on out-of-bounds access into macro node array
• fd6756e: 8257634: C2: Introduce IncrementalInliningForceCleanup diagnostic flag
• af6b7f9: 8257743: Minimal build on AArch64 failed with --disable-precompiled-headers
• d6dd440: 8256264: Printed GlyphVector outline with low DPI has bad quality on Windows
• 2b4a423: 8255542: Attribute length of Module, ModulePackages and other attributes is ignored
• ca40267: 8257509: Strengthen requirements to call G1HeapVerifier::verify(VerifyOption)
• ... and 70 more: https://git.openjdk.java.net/jdk/compare/eaf4db6b8b883b1ab5731ac62f590e39a7b67210...master

Your commit was automatically rebased without conflicts.

Pushed as commit 86b6575.

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