8254369: Node::disconnect_inputs may skip precedences

[navyxliu]

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Testing

	Linux x64	Windows x64	macOS x64
Build	✔️ (5/5 passed)	✔️ (2/2 passed)	✔️ (2/2 passed)
Test (tier1)	✔️ (9/9 passed)	✔️ (9/9 passed)	✔️ (9/9 passed)

Issue

• JDK-8254369: Node::disconnect_inputs may skip precedences

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer)
• Claes Redestad (@cl4es - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/664/head:pull/664
$ git checkout pull/664

[bridgekeeper]

👋 Welcome back xliu! 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]

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

• hotspot-compiler

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 02: Full - Incremental (5846057)
• 01: Full - Incremental (bc809ff)
• 00: Full (f3f9c27)

[navyxliu]

/summary
disconnect_inputs() needs to iterate precedences edges in reverse order because rm_prec(i) may backfill _in[i] with a value afterward.
also remove the predicate if (n != NULL) in set_prec because it's always true.

[openjdk]

@navyxliu Setting summary to:

disconnect_inputs() needs to iterate precedences edges in reverse order because rm_prec(i) may backfill _in[i] with a value afterward.
also remove the predicate if (n != NULL) in set_prec because it's always true.

[cl4es]

Looks good, whether you decide to incorporate my suggestion below or not

[openjdk]

@navyxliu 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:

8254369: Node::disconnect_inputs may skip precedences

disconnect_inputs() needs to iterate precedences edges in reverse order because rm_prec(i) may backfill _in[i] with a value afterward.
also remove the predicate if (n != NULL) in set_prec because it's always true.

Reviewed-by: kvn, redestad

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 37 new commits pushed to the master branch:

• 96bb6e7: 8251325: Miss 'L' for long value in if statement
• 546620b: 8254192: ExtraSharedClassListFile contains extra white space at end of line
• f3ce45f: 8254799: runtime/ErrorHandling/TestHeapDumpOnOutOfMemoryError.java fails with release VMs
• cda22e3: 8254811: JDK-8254158 broke ppc64, s390 builds
• 8ef88e5: 8249878: jfr_emergency_dump has secondary crashes
• 3c2f5e0: 8254674: G1: Improve root location reference to dead obj verification message
• abe5137: 8254719: ZGC: Clean up includes
• 60159cf: 8253952: Refine ZipOutputStream.putNextEntry() to recalculate ZipEntry's compressed size
• 9359ff0: 8252221: Use multiple workers for Parallel GC pre-touching
• f44fc6d: 8254734: "dead loop detected" assert failure with patch from 8223051
• ... and 27 more: https://git.openjdk.java.net/jdk/compare/a09803737516cfc95fdba397f53af9ad0f88e1b8...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 (@vnkozlov, @cl4es) 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).

[cl4es]

"where's the if(len() > 0)" I thought for a second, but you're right: len() >= req(), so if len() is 0, then req() must be 0, too, which means len() > req() is false and we won't accidentally call rm_prec(UINT_MAX)

[vnkozlov]

Good.

[navyxliu]

/integrate

[openjdk]

@navyxliu
Your change (at version 5846057) is now ready to be sponsored by a Committer.

[vnkozlov]

hs-tier1 passed

[vnkozlov]

/sponsor

[openjdk]

@vnkozlov @navyxliu Since your change was applied there have been 37 commits pushed to the master branch:

• 96bb6e7: 8251325: Miss 'L' for long value in if statement
• 546620b: 8254192: ExtraSharedClassListFile contains extra white space at end of line
• f3ce45f: 8254799: runtime/ErrorHandling/TestHeapDumpOnOutOfMemoryError.java fails with release VMs
• cda22e3: 8254811: JDK-8254158 broke ppc64, s390 builds
• 8ef88e5: 8249878: jfr_emergency_dump has secondary crashes
• 3c2f5e0: 8254674: G1: Improve root location reference to dead obj verification message
• abe5137: 8254719: ZGC: Clean up includes
• 60159cf: 8253952: Refine ZipOutputStream.putNextEntry() to recalculate ZipEntry's compressed size
• 9359ff0: 8252221: Use multiple workers for Parallel GC pre-touching
• f44fc6d: 8254734: "dead loop detected" assert failure with patch from 8223051
• ... and 27 more: https://git.openjdk.java.net/jdk/compare/a09803737516cfc95fdba397f53af9ad0f88e1b8...master

Your commit was automatically rebased without conflicts.

Pushed as commit bdda205.

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