From daniel.smith at oracle.com  Mon Jan  5 23:21:56 2026
From: daniel.smith at oracle.com (Dan Smith)
Date: Mon, 5 Jan 2026 23:21:56 +0000
Subject: Porting to support JEP 401: Value Classes and Objects (Preview)
Message-ID: <085DD22C-C0D6-4E47-94E2-533AE72381AB@oracle.com>

Hello, porters! The Valhalla project has been implementing JEP 401: Value Classes and Objects (Preview) in a branch of our Github repository. Over the next few months, we will be preparing to target and integrate the JEP.

This will be a very large commit touching many components of HotSpot, so now is a good time to start aligning your ports with the anticipated changes and ensuring conformance with the updated specifications.

Some pointers:

Value Classes JEP: https://openjdk.org/jeps/401
Supplementary strict field initialization JEP: https://openjdk.org/jeps/8350458

JVMS changes (value classes): https://cr.openjdk.org/~dlsmith/jep401/jep401-20251210/specs/value-objects-jvms.html
JVMS changes (field initialization): https://cr.openjdk.org/~dlsmith/jep401/jep401-20251210/specs/strict-fields-jvms.html

Git branch: https://github.com/openjdk/valhalla/tree/lworld

As a baseline, you may want to focus on *compliance* without adopting any of the value object *optimizations*. A compliant JVM will recognize and validate the ACC_IDENTITY and ACC_STRICT_INIT flags, and will follow the new semantics for 'acmp', 'ifnull', and 'monitorenter'; but can ignore the contents of 'LoadableDescriptors', and need not support scalarized or flattened object encodings.

Please reach out to valhalla-dev, or to me personally, if you need any help or clarifications to align with these changes.

From martin.doerr at sap.com  Thu Jan  8 22:24:31 2026
From: martin.doerr at sap.com (Doerr, Martin)
Date: Thu, 8 Jan 2026 22:24:31 +0000
Subject: Porting to support JEP 401: Value Classes and Objects (Preview)
In-Reply-To: <085DD22C-C0D6-4E47-94E2-533AE72381AB@oracle.com>
References: <085DD22C-C0D6-4E47-94E2-533AE72381AB@oracle.com>
Message-ID: <AS8PR02MB8544FD856E4859BC97C879439A85A@AS8PR02MB8544.eurprd02.prod.outlook.com>

Hi Dan,

Thanks for the heads-up! We will look into it and plan a PPC64 port.

Best regards,
Martin

Von: porters-dev <porters-dev-retn at openjdk.org> im Auftrag von Dan Smith <daniel.smith at oracle.com>
Datum: Dienstag, 6. Januar 2026 um 00:22
An: porters-dev at openjdk.org <porters-dev at openjdk.org>
Betreff: Porting to support JEP 401: Value Classes and Objects (Preview)

Hello, porters! The Valhalla project has been implementing JEP 401: Value Classes and Objects (Preview) in a branch of our Github repository. Over the next few months, we will be preparing to target and integrate the JEP.

This will be a very large commit touching many components of HotSpot, so now is a good time to start aligning your ports with the anticipated changes and ensuring conformance with the updated specifications.

Some pointers:

Value Classes JEP: https://openjdk.org/jeps/401
Supplementary strict field initialization JEP: https://openjdk.org/jeps/8350458

JVMS changes (value classes): https://cr.openjdk.org/~dlsmith/jep401/jep401-20251210/specs/value-objects-jvms.html
JVMS changes (field initialization): https://cr.openjdk.org/~dlsmith/jep401/jep401-20251210/specs/strict-fields-jvms.html

Git branch: https://github.com/openjdk/valhalla/tree/lworld

As a baseline, you may want to focus on *compliance* without adopting any of the value object *optimizations*. A compliant JVM will recognize and validate the ACC_IDENTITY and ACC_STRICT_INIT flags, and will follow the new semantics for 'acmp', 'ifnull', and 'monitorenter'; but can ignore the contents of 'LoadableDescriptors', and need not support scalarized or flattened object encodings.

Please reach out to valhalla-dev, or to me personally, if you need any help or clarifications to align with these changes.
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From yangfei at iscas.ac.cn  Fri Jan 16 07:42:27 2026
From: yangfei at iscas.ac.cn (yangfei at iscas.ac.cn)
Date: Fri, 16 Jan 2026 15:42:27 +0800 (GMT+08:00)
Subject: Porting to support JEP 401: Value Classes and Objects
 (Preview)
In-Reply-To: <AS8PR02MB8544FD856E4859BC97C879439A85A@AS8PR02MB8544.eurprd02.prod.outlook.com>
References: <085DD22C-C0D6-4E47-94E2-533AE72381AB@oracle.com>
 <AS8PR02MB8544FD856E4859BC97C879439A85A@AS8PR02MB8544.eurprd02.prod.outlook.com>
Message-ID: <327efbcb.5cce.19bc5c170d8.Coremail.yangfei@iscas.ac.cn>

Hi Dan,

  Nice work! Thanks for letting us know.
  We are looking at the code changes as well and will try to prepare a RISC-V port.

Thanks,
Fei


-----Original Messages-----
From:"Doerr, Martin" <martin.doerr at sap.com>
Sent Time:2026-01-09 06:24:31 (Friday)
To: "Dan Smith" <daniel.smith at oracle.com>, "porters-dev at openjdk.org" <porters-dev at openjdk.org>
Cc: "Amit Kumar" <amit.kumar220 at ibm.com>
Subject: Re: Porting to support JEP 401: Value Classes and Objects (Preview)

Hi Dan, 
 
 Thanks for the heads-up! We will look into it and plan a PPC64 port. 
 
 Best regards, 
 Martin 
 
 
  Von: porters-dev <porters-dev-retn at openjdk.org> im Auftrag von Dan Smith <daniel.smith at oracle.com>
Datum: Dienstag, 6. Januar 2026 um 00:22
An: porters-dev at openjdk.org <porters-dev at openjdk.org>
Betreff: Porting to support JEP 401: Value Classes and Objects (Preview)

Hello, porters! The Valhalla project has been implementing JEP 401: Value Classes and Objects (Preview) in a branch of our Github repository. Over the next few months, we will be preparing to target and integrate the JEP.

This will be a very large commit touching many components of HotSpot, so now is a good time to start aligning your ports with the anticipated changes and ensuring conformance with the updated specifications.

Some pointers:

Value Classes JEP: https://openjdk.org/jeps/401
Supplementary strict field initialization JEP: https://openjdk.org/jeps/8350458

JVMS changes (value classes): https://cr.openjdk.org/~dlsmith/jep401/jep401-20251210/specs/value-objects-jvms.html
JVMS changes (field initialization): https://cr.openjdk.org/~dlsmith/jep401/jep401-20251210/specs/strict-fields-jvms.html

Git branch: https://github.com/openjdk/valhalla/tree/lworld

As a baseline, you may want to focus on *compliance* without adopting any of the value object *optimizations*. A compliant JVM will recognize and validate the ACC_IDENTITY and ACC_STRICT_INIT flags, and will follow the new semantics for 'acmp', 'ifnull', and 'monitorenter'; but can ignore the contents of 'LoadableDescriptors', and need not support scalarized or flattened object encodings.

Please reach out to valhalla-dev, or to me personally, if you need any help or clarifications to align with these changes.



From kim.barrett at oracle.com  Fri Jan 30 00:22:53 2026
From: kim.barrett at oracle.com (Kim Barrett)
Date: Thu, 29 Jan 2026 19:22:53 -0500
Subject: AIX testing needed for -Wzero-as-null-pointer-constant
Message-ID: <619e6526-3370-4858-8274-10f883d24cce@oracle.com>

I'd like someone with access to AIX to try out this change:
https://github.com/openjdk/jdk/pull/29497

It enables -Wzero-as-null-pointer-constant for gcc/clang.  I think all of the
shared and ppc code should be clean.  I've fixed some cases in AIX-specific
code.  There might be some I missed though, as I found those by just looking
at the code.

So I'd like someone to try building the code from that PR and report what you
find.  Once I know AIX is clean I can proceed to turning on the warning.

From sxa at redhat.com  Fri Jan 30 17:13:29 2026
From: sxa at redhat.com (Stewart X Addison)
Date: Fri, 30 Jan 2026 17:13:29 +0000
Subject: AIX testing needed for -Wzero-as-null-pointer-constant
In-Reply-To: <619e6526-3370-4858-8274-10f883d24cce@oracle.com>
References: <619e6526-3370-4858-8274-10f883d24cce@oracle.com>
Message-ID: <CAL5aOfojESbxLFGRu8L-75QhhB00E6soU+hO-h2DX3bgn_D5rg@mail.gmail.com>

Hi Kim,

As far as I can tell the CI job at
https://ci.adoptium.net/job/build-scripts/job/jobs/job/jdk/job/jdk-aix-ppc64-temurin/467/console
has
run successfully from your branch with the compilers we use at Adoptium ??

Regards,

Stewart...
--
Working for Red Hat <https://www.redhat.com> on Adoptium Temurin
<https://adoptium.net> and Node.js
<http://nodejs.org>
https://fosstodon.org/@sxa
https://github.com/sxa
<http://nodejs.org>



On Fri, 30 Jan 2026 at 00:24, Kim Barrett <kim.barrett at oracle.com> wrote:

> I'd like someone with access to AIX to try out this change:
> https://github.com/openjdk/jdk/pull/29497
>
> It enables -Wzero-as-null-pointer-constant for gcc/clang.  I think all of
> the
> shared and ppc code should be clean.  I've fixed some cases in AIX-specific
> code.  There might be some I missed though, as I found those by just
> looking
> at the code.
>
> So I'd like someone to try building the code from that PR and report what
> you
> find.  Once I know AIX is clean I can proceed to turning on the warning.
>
>
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From kim.barrett at oracle.com  Fri Jan 30 22:01:34 2026
From: kim.barrett at oracle.com (Kim Barrett)
Date: Fri, 30 Jan 2026 17:01:34 -0500
Subject: AIX testing needed for -Wzero-as-null-pointer-constant
In-Reply-To: <CAL5aOfojESbxLFGRu8L-75QhhB00E6soU+hO-h2DX3bgn_D5rg@mail.gmail.com>
References: <619e6526-3370-4858-8274-10f883d24cce@oracle.com>
 <CAL5aOfojESbxLFGRu8L-75QhhB00E6soU+hO-h2DX3bgn_D5rg@mail.gmail.com>
Message-ID: <451a5b82-e54e-4c8d-a329-61e3d5294100@oracle.com>

On 1/30/26 12:13 PM, Stewart X Addison wrote:
> Hi Kim,
> 
> As far as I can tell the CI job at https://ci.adoptium.net/job/build-scripts/job/jobs/job/jdk/job/jdk-aix-ppc64-temurin/467/console <https://urldefense.com/v3/__https://ci.adoptium.net/job/build-scripts/job/jobs/job/jdk/job/jdk-aix-ppc64-temurin/467/console__;!!ACWV5N9M2RV99hQ!I02CZBteZQJMIFrMCxNWs65KuaDWaBUUgaT77JcVbEQFgOsGv2moAtdHEAoTYVhyfvKPfebI8nIf$>?has run successfully from your branch with the compilers we use at Adoptium ??

Thanks for testing.

I'll move forward with these changes.