8216437: PPC64: Add intrinsic for GHASH algorithm

[suchismith1993]

Hi all,

This pull request contains a backport of commit cdad6d78 from the openjdk/jdk repository.

The commit being backported was authored by Suchismith Roy on 2 May 2025 and was reviewed by Martin Doerr and Amit Kumar.

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-8216437 needs maintainer approval

Issue

• JDK-8216437: PPC64: Add intrinsic for GHASH algorithm (Enhancement - P4 - Requested)

Reviewers

• Martin Doerr (@TheRealMDoerr - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/1789/head:pull/1789
$ git checkout pull/1789

Update a local copy of the PR:
$ git checkout pull/1789
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/1789/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 1789

View PR using the GUI difftool:
$ git pr show -t 1789

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/1789.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back sroy! 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]

⚠️ @suchismith1993 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

• 02: Full - Incremental (11b87982)
• 01: Full - Incremental (bf0ad564)
• 00: Full (76a3b83f)

[openjdk]

@suchismith1993
8216437: The approval request has been created successfully.

[suchismith1993]

Need to adapt code for jdk21 repo. Looking into it

[suchismith1993]

/approval request Need GHASH for jdk21

[openjdk]

@suchismith1993
8216437: The approval request has been updated successfully.

[TheRealMDoerr]

Backport looks correct.

[suchismith1993]

/approval ghash fix needed for jdk21

[suchismith1993]

/approval request ghash fix needed for jdk21

[openjdk]

@suchismith1993 usage: /approval [<id>] (request|cancel) [<text>]

[openjdk]

@suchismith1993
8216437: The approval request has been updated successfully.

[suchismith1993]

/integrate

[openjdk]

@suchismith1993 This pull request has not yet been marked as ready for integration.

[GoeLin]

Hi @suchismith1993
please give a fix request comment that gives the necessary details.
The change is definitely not needed for 21, probably a nice-to-have performance optimization.

This has not been tested in any released JVM yet, do you really want to bring it to 21 now?

[suchismith1993]

Hi @suchismith1993 please give a fix request comment that gives the necessary details. The change is definitely not needed for 21, probably a nice-to-have performance optimization.

This has not been tested in any released JVM yet, do you really want to bring it to 21 now?

It has been tested on the headstream, but not sure which release it would be a part of. 21 is LTS and used by many customers, so the optimisation should be a good addition.
@TheRealMDoerr Your thoughts ?

[TheRealMDoerr]

It will be released with JDK25 in September. The October Update of JDK21 should be ok for the backport. The tests should have covered it well enough. If we want some extra safety, postponing to January Update would be ok with me, too.

[suchismith1993]

@TheRealMDoerr @GoeLin so we wait at least till October ? So should this PR be closed now ?

[TheRealMDoerr]

No, you can integrate it after you got maintainer approval.

[suchismith1993]

@GoeLin can it be approved now ? or shall we hold till October ?

[GoeLin]

Hi Suchismith,
I labeled it jdk21u-defer-next.
Also, you did not update the fix-request comment yet. There should be good information about this in the JBS issue. The purpose of the PR is only to review it.

[suchismith1993]

/approval request The fix provides a 3x performance benefit. JDK21 is LTS and used by many customers, so this fix is essential.

[openjdk]

@suchismith1993
8216437: The approval request has been updated successfully.