8373502: C2 SuperWord: speculative check uses VPointer variable was pinned after speculative check, leading to bad graph

[eme64]

Clean backport of #28783 to JDK26.

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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-8373502: C2 SuperWord: speculative check uses VPointer variable was pinned after speculative check, leading to bad graph (Bug - P3)

Reviewers

• Manuel Hässig (@mhaessig - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/28929/head:pull/28929
$ git checkout pull/28929

Update a local copy of the PR:
$ git checkout pull/28929
$ git pull https://git.openjdk.org/jdk.git pull/28929/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 28929

View PR using the GUI difftool:
$ git pr show -t 28929

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/28929.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back epeter! A progress list of the required criteria for merging this PR into jdk26 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 change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

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

[openjdk]

@eme64 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

• 00: Full (b9231032)

[mhaessig]

Looks good to me.