8365570: C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII

[vish-chan]

Clean backport of 8365570 - C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII

• Fixes assert failure in superword truncation with CastII. Since casts specifically change the type of a node, they should not be truncated during vectorization to maintain type safety.

• Additional Testing:

• New regression test fails without the fix, passes with it.
• Linux x86_64 server fastebug compiler tests.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8365570 needs maintainer approval

Issue

• JDK-8365570: C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII (Bug - P3 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk25u-dev.git pull/269/head:pull/269
$ git checkout pull/269

Update a local copy of the PR:
$ git checkout pull/269
$ git pull https://git.openjdk.org/jdk25u-dev.git pull/269/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 269

View PR using the GUI difftool:
$ git pr show -t 269

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk25u-dev/pull/269.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back vish-chan! 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]

@vish-chan 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:

8365570: C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII

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 43 new commits pushed to the master branch:

• 30a962c: 8375999: com/sun/jndi/ldap/LdapPoolTimeoutTest.java fails sporadically on Windows
• 78ae7bd: 8360702: runtime/Thread/AsyncExceptionTest.java timed out
• cae18ed: 8371349: Update NSS library to 3.117
• ... and 40 more: https://git.openjdk.org/jdk25u-dev/compare/5c40aa76793dbf252dba4dba5b4f5bb2f5a3b3d8...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.

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➡️ 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).

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

⚠️ @vish-chan 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 (76da8720)

[vish-chan]

/approval request for Clean backport of 8365570 - C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII

This is a low risk fix as it fixes assert failure in superword truncation with CastII. Since casts specifically change the type of a node, they should not be truncated during vectorization to maintain type safety.

[openjdk]

@vish-chan
8365570: The approval request has been created successfully.

[vish-chan]

/integrate

[openjdk]

@vish-chan
Your change (at version 76da872) is now ready to be sponsored by a Committer.

[phohensee]

/sponsor

[openjdk]

Going to push as commit be61f28.
Since your change was applied there have been 47 commits pushed to the master branch:

• a17be59: 8377811: [25u] G1: Optional Evacuations may evacuate pinned objects
• f5d2cf3: 8377898: Hotspot build on AIX with unused-functions warning reports some unused functions
• 9878c7e: 8376889: Enhance JfrRecorder::on_create_vm_3() assert output
• ... and 44 more: https://git.openjdk.org/jdk25u-dev/compare/5c40aa76793dbf252dba4dba5b4f5bb2f5a3b3d8...master

Your commit was automatically rebased without conflicts.

[openjdk]

@phohensee @vish-chan Pushed as commit be61f28.

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