8321025: Enable Neoverse N1 optimizations for Neoverse V2

[pengxiaolong]

Notes

Backport 8321025: Enable Neoverse N1 optimizations for Neoverse V2 to jdk21 it is not a clean backport, the method model_is(0xd40) is in jdk21, equivalent code in jdk21 is like (_model == 0xd40 || _model2 == 0xd40).

Verification

Not able to test it on CPU with Neoverse V2, since I don't have server supports Neoverse V2 yet, but the fix has been backported to Amazon Corretto 21 since January 16, 2024, overall it should be a low risk.

---

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-8321025 needs maintainer approval

Issue

• JDK-8321025: Enable Neoverse N1 optimizations for Neoverse V2 (Enhancement - P4 - Approved)

Reviewers

• Aleksey Shipilev (@shipilev - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/720/head:pull/720
$ git checkout pull/720

Update a local copy of the PR:
$ git checkout pull/720
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/720/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 720

View PR using the GUI difftool:
$ git pr show -t 720

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/720.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back xpeng! 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]

@pengxiaolong 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:

8321025: Enable Neoverse N1 optimizations for Neoverse V2

Reviewed-by: shade

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 24 new commits pushed to the master branch:

• 2e8418e: 8313697: [XWayland][Screencast] consequent getPixelColor calls are slow
• f2e567a: 8301686: TLS 1.3 handshake fails if server_name doesn't match resuming session
• ef30dbc: 8308660: C2 compilation hits 'node must be dead' assert
• 4af7862: 8322743: C2: prevent lock region elimination in OSR compilation
• a5eb7f2: 8329088: Stack chunk thawing races with concurrent GC stack iteration
• fcd7fb7: 8331142: Add test for number of loader threads in BasicDirectoryModel
• 686d69d: 8328115: Convert java/awt/font/TextLayout/TestJustification.html applet test to main
• aeae521: 8327137: Add test for ConcurrentModificationException in BasicDirectoryModel
• b0894f2: 8328011: Convert java/awt/Frame/GetBoundsResizeTest/GetBoundsResizeTest.java applet test to main
• 7cf4272: 8327650: Test java/nio/channels/DatagramChannel/StressNativeSignal.java timed out
• ... and 14 more: https://git.openjdk.org/jdk21u-dev/compare/ccfae880577ab5b071815de13474e8987b45c943...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 (@shipilev) 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).

[openjdk]

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

[mlbridge]

Webrevs

• 00: Full (cc0ec95c)

[openjdk]

⚠️ @pengxiaolong 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.

[pengxiaolong]

Thanks Aleksey for reviewing the PR and the suggestions!

[pengxiaolong]

/approval request Backport JDK-8321025 to jdk21 for to enable Neoverse N1 optimizations for Neoverse V2, it was not a clean backport, also backported VM_Version::model_is from openjdk/jdk@3283328 when resolving the conflicts. Risk should be low, it was backported to Amazon-Corretto-21 in Jan 2024, no known issue so far.

[openjdk]

@pengxiaolong
8321025: The approval request has been created successfully.

[pengxiaolong]

Thanks all! I'll start integrate.

[pengxiaolong]

/integrate

[openjdk]

@pengxiaolong
Your change (at version cc0ec95) is now ready to be sponsored by a Committer.

[shipilev]

/sponsor

[openjdk]

Going to push as commit 943e759.
Since your change was applied there have been 24 commits pushed to the master branch:

• 2e8418e: 8313697: [XWayland][Screencast] consequent getPixelColor calls are slow
• f2e567a: 8301686: TLS 1.3 handshake fails if server_name doesn't match resuming session
• ef30dbc: 8308660: C2 compilation hits 'node must be dead' assert
• 4af7862: 8322743: C2: prevent lock region elimination in OSR compilation
• a5eb7f2: 8329088: Stack chunk thawing races with concurrent GC stack iteration
• fcd7fb7: 8331142: Add test for number of loader threads in BasicDirectoryModel
• 686d69d: 8328115: Convert java/awt/font/TextLayout/TestJustification.html applet test to main
• aeae521: 8327137: Add test for ConcurrentModificationException in BasicDirectoryModel
• b0894f2: 8328011: Convert java/awt/Frame/GetBoundsResizeTest/GetBoundsResizeTest.java applet test to main
• 7cf4272: 8327650: Test java/nio/channels/DatagramChannel/StressNativeSignal.java timed out
• ... and 14 more: https://git.openjdk.org/jdk21u-dev/compare/ccfae880577ab5b071815de13474e8987b45c943...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev @pengxiaolong Pushed as commit 943e759.

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