8372978: [VectorAPI] Fix incorrect identity values in UMIN/UMAX reductions

[erifan]

Hi all,

This pull request contains a backport of commit 56d7b524 from the openjdk/jdk repository.

The commit being backported was authored by Eric Fang on 14 Jan 2026 and was reviewed by Paul Sandoz, Quan Anh Mai and Xiaohong Gong.

Thanks!

---

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
• JDK-8372978 needs maintainer approval

Issue

• JDK-8372978: [VectorAPI] Fix incorrect identity values in UMIN/UMAX reductions (Bug - P3)

Reviewers

• Xiaohong Gong (@XiaohongGong - no project role)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk25u-dev.git pull/150/head:pull/150
$ git checkout pull/150

Update a local copy of the PR:
$ git checkout pull/150
$ git pull https://git.openjdk.org/jdk25u-dev.git pull/150/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 150

View PR using the GUI difftool:
$ git pr show -t 150

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk25u-dev/pull/150.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back erfang! 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]

❗ 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]

⚠️ @erifan This backport pull request is too large to be automatically evaluated as clean.

[mlbridge]

Webrevs

• 00: Full (c120e489)

[erifan]

Hi @PaulSandoz @XiaohongGong @merykitty Would you mind taking a look of this backporting PR, thanks~