Skip to content
This repository has been archived by the owner on Sep 19, 2023. It is now read-only.

8287851: C2 crash: assert(t->meet(t0) == t) failed: Not monotonic #104

Closed
wants to merge 1 commit into from

Conversation

jatin-bhateja
Copy link
Member

@jatin-bhateja jatin-bhateja commented Jul 2, 2022

Hi All,

Patch fixes the assertion failure seen during conditional constant propagation optimization on account of
non-convergence, this happens when type values (lattice) associated with IR node seen during iterative data flow analysis are not-monotonic.

Problem was occurring due to incorrect result value range estimation by Value routines associated with Compress/ExpandBits IR nodes, non-constant mask lattice can take any value between _lo and _hi values, special handling for +ve mask value range is using count_leading_zeros to estimate the maximum bit width needed to accommodate the result. Since count_leading_zeros
accepts a long argument there by sign-extending integer argument, hence for integer case we need to subtract 32 from the results to get correct value.

Patch also fixes a typo resulting into a dead code reported by JDK-8287855: Problem in compress_expand_identity.

Failing unit test java/lang/CompressExpandTest.java has been removed from ProblemList.txt.

Kindly review and share your feedback.

Best Regards,
Jatin


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-8287851: C2 crash: assert(t->meet(t0) == t) failed: Not monotonic

Reviewers

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk19 pull/104/head:pull/104
$ git checkout pull/104

Update a local copy of the PR:
$ git checkout pull/104
$ git pull https://git.openjdk.org/jdk19 pull/104/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 104

View PR using the GUI difftool:
$ git pr show -t 104

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk19/pull/104.diff

@jatin-bhateja
Copy link
Member Author

/label add hotspot-compiler-dev

@bridgekeeper
Copy link

bridgekeeper bot commented Jul 2, 2022

👋 Welcome back jbhateja! 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 openjdk bot added rfr Pull request is ready for review hotspot-compiler hotspot-compiler-dev@openjdk.org labels Jul 2, 2022
@openjdk
Copy link

openjdk bot commented Jul 2, 2022

@jatin-bhateja
The hotspot-compiler label was successfully added.

@mlbridge
Copy link

mlbridge bot commented Jul 2, 2022

Webrevs

Copy link
Member

@TobiHartmann TobiHartmann left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good to me. Can we close JDK-8287855 as duplicate then?

I'll run testing and report back once it passed.

@openjdk
Copy link

openjdk bot commented Jul 4, 2022

@jatin-bhateja 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:

8287851: C2 crash: assert(t->meet(t0) == t) failed: Not monotonic

Reviewed-by: thartmann, 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 2 new commits pushed to the master branch:

  • dc4edd3: 8289183: jdk.jfr.consumer.RecordedThread.getId references Thread::getId, should be Thread::threadId
  • c4dcce4: 8289619: JVMTI SelfSuspendDisablerTest.java failed with RuntimeException: Test FAILED: Unexpected thread state

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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 openjdk bot added the ready Pull request is ready to be integrated label Jul 4, 2022
Copy link
Member

@chhagedorn chhagedorn left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good!

@jatin-bhateja
Copy link
Member Author

Looks good to me. Can we close JDK-8287855 as duplicate then?

I'll run testing and report back once it passed.

Hi @TobiHartmann , yes l will resolve 8287855 manually with comments, will check-in once you share test results.

@TobiHartmann
Copy link
Member

Thanks. All tests passed.

@jatin-bhateja
Copy link
Member Author

Thanks @TobiHartmann , @chhagedorn for reviews.

@jatin-bhateja
Copy link
Member Author

/integrate

@openjdk
Copy link

openjdk bot commented Jul 4, 2022

Going to push as commit 1a27164.
Since your change was applied there have been 3 commits pushed to the master branch:

  • 5b5bc6c: 8287672: jtreg test com/sun/jndi/ldap/LdapPoolTimeoutTest.java fails intermittently in nightly run
  • dc4edd3: 8289183: jdk.jfr.consumer.RecordedThread.getId references Thread::getId, should be Thread::threadId
  • c4dcce4: 8289619: JVMTI SelfSuspendDisablerTest.java failed with RuntimeException: Test FAILED: Unexpected thread state

Your commit was automatically rebased without conflicts.

@openjdk openjdk bot added the integrated Pull request has been integrated label Jul 4, 2022
@openjdk openjdk bot closed this Jul 4, 2022
@openjdk openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Jul 4, 2022
@openjdk
Copy link

openjdk bot commented Jul 4, 2022

@jatin-bhateja Pushed as commit 1a27164.

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

Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Labels
hotspot-compiler hotspot-compiler-dev@openjdk.org integrated Pull request has been integrated
3 participants