8365579: ml64.exe is not the right assembler for Windows aarch64 #26791

swesonga · 2025-08-14T23:59:23Z

ml64 is set as the assembler for the Windows platform but is specific to the x64 platform. The armasm64 assembler should be used for Windows AArch64.

The -c and -Ta options are only valid for ml64 and -Ta can be removed from CompileFile.gmk (assembling for x64 works without it).

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-8365579: ml64.exe is not the right assembler for Windows aarch64 (Bug - P4)

Reviewers

Julian Waters (@TheShermanTanker - Committer)
Erik Joelsson (@erikj79 - Reviewer) Review applies to 2ae8f30c
Magnus Ihse Bursie (@magicus - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/26791/head:pull/26791
$ git checkout pull/26791

Update a local copy of the PR:
$ git checkout pull/26791
$ git pull https://git.openjdk.org/jdk.git pull/26791/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 26791

View PR using the GUI difftool:
$ git pr show -t 26791

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/26791.diff

Using Webrev

Link to Webrev Comment

bridgekeeper · 2025-08-15T00:00:10Z

👋 Welcome back swesonga! 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 · 2025-08-15T00:01:40Z

@swesonga 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:

8365579: ml64.exe is not the right assembler for Windows aarch64

Reviewed-by: jwaters, ihse, erikj

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 126 new commits pushed to the master branch:

1a7ac16: 8364382: Remove sun/tools/jstat/jstatLineCountsX.sh from ProblemList on linux-ppc64le and aix due to JDK-8248691
63faa50: 8365291: Remove finalize() method from sun/awt/X11InputMethodBase.java
040cc7a: 8365292: Remove javax.imageio.spi.ServiceRegistry.finalize()
... and 123 more: https://git.openjdk.org/jdk/compare/b0f98df75aee1e94a8c4b3eb8d0b1f4e715011ae...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 (@TheShermanTanker, @erikj79, @magicus) 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 · 2025-08-15T00:02:41Z

@swesonga The following label will be automatically applied to this pull request:

build

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 · 2025-08-15T00:06:27Z

Webrevs

TheShermanTanker

I'd prefer if -Ta could be kept somehow but there doesn't seem to be a clean way to do that, so this gets a +1 from me anyway

erikj79 · 2025-08-15T14:26:00Z

make/common/native/CompileFile.gmk

 	    $$(call ExecuteWithLog, $$@, $$(call MakeCommandRelative, \
 	        $$($1_COMPILER) $$($1_FLAGS) \
-	        $(CC_OUT_OPTION)$$($1_OBJ) -Ta $$($1_SRC_FILE))) \
+	        $(CC_OUT_OPTION)$$($1_OBJ) $$($1_SRC_FILE))) \


Have you verified that removing -Ta works for the x86 assembler?

Have you verified that removing -Ta works for the x86 assembler?

Yes, both of these command lines work:

; "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.44.35207\bin\Hostx64\x86\ml.exe" -nologo -c -Fo test_x86_assembler.obj -Ta test_x86_assembler.S ; "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.44.35207\bin\Hostx64\x86\ml.exe" -nologo -c -Fo test_x86_assembler.obj test_x86_assembler.S TEST_SEG SEGMENT mov eax, ecx TEST_SEG ENDS END

I wonder why we still have the assembler for 32 bit, as the JDK no longer supports 32 bit Windows ever since Magnus nuked it from the codebase

I wonder why we still have the assembler for 32 bit, as the JDK no longer supports 32 bit Windows ever since Magnus nuked it from the codebase

I have filed https://bugs.openjdk.org/browse/JDK-8365707 to address that issue

Is this really so? The documentation states:

/Ta filename Assembles source file whose name doesn't end with the .asm extension.

We want the compiler to actually do what we tell it to do, even if the files are named .S.

Maybe this behavior has been changed in later versions, but I am a bit wary about removing it unless we have some official confirmation that /Ta is a no-op, and/or information on which version this started to happen.

erikj79 · 2025-08-15T14:26:56Z

make/autoconf/toolchain.m4

    else
-      # otherwise, the assembler is "ml.exe"
-      UTIL_LOOKUP_TOOLCHAIN_PROGS(AS, ml)
+      if test "x$OPENJDK_TARGET_CPU_BITS" = "x64"; then
+        # On Windows x64, the assembler is "ml64.exe"
+        UTIL_LOOKUP_TOOLCHAIN_PROGS(AS, ml64)
+      else
+        # otherwise, the assembler is "ml.exe"
+        UTIL_LOOKUP_TOOLCHAIN_PROGS(AS, ml)
+      fi


I think this would be more readable as an elif with all the cases on the same level rather than nesting the second if/else inside the else block.

TheShermanTanker

This is still ok with me

swesonga · 2025-08-15T17:29:59Z

/integrate

openjdk · 2025-08-15T17:31:34Z

@swesonga
Your change (at version 2ae8f30) is now ready to be sponsored by a Committer.

sendaoYan · 2025-08-18T07:04:59Z

make/autoconf/flags-other.m4

    # Force preprocessor to run, just to make sure
    BASIC_ASFLAGS="-x assembler-with-cpp"
  elif test "x$TOOLCHAIN_TYPE" = xmicrosoft; then
-    BASIC_ASFLAGS="-nologo -c"


Should we need to update the copyright year from 2024 to 2025

Yes, please that would be good.

magicus · 2025-08-23T08:34:40Z

I'd like to see some more investigation into the removal of -Ta before integration, since it is documented as required.

An alternative to investigation is to keep it for ml64, by creating a new variable exposed to spec.gmk, similar to how cl.exe needs a -out: (or whatever it was called) for where to .obj files.

magicus

I'd envisioned setting it in configure like other flags, but I guess this works. (I've always been a bit skeptical towards setting compiler "infrastructure" flags from configure, so in the long term I'd like to migrate such flags to make.)

swesonga · 2025-08-25T20:20:23Z

/integrate

openjdk · 2025-08-25T20:22:04Z

@swesonga
Your change (at version 4279637) is now ready to be sponsored by a Committer.

sendaoYan · 2025-08-26T01:13:04Z

/sponsor

openjdk · 2025-08-26T01:13:57Z

Going to push as commit a629424.
Since your change was applied there have been 126 commits pushed to the master branch:

1a7ac16: 8364382: Remove sun/tools/jstat/jstatLineCountsX.sh from ProblemList on linux-ppc64le and aix due to JDK-8248691
63faa50: 8365291: Remove finalize() method from sun/awt/X11InputMethodBase.java
040cc7a: 8365292: Remove javax.imageio.spi.ServiceRegistry.finalize()
... and 123 more: https://git.openjdk.org/jdk/compare/b0f98df75aee1e94a8c4b3eb8d0b1f4e715011ae...master

Your commit was automatically rebased without conflicts.

openjdk · 2025-08-26T01:14:07Z

@sendaoYan @swesonga Pushed as commit a629424.

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

TheShermanTanker · 2025-08-26T12:35:21Z

I actually missed this earlier, but I don't believe the quotes around -Ta are needed. It doesn't seem to do any harm though, so I'm not sure if anyone else would want to remove them

magicus · 2025-08-26T13:58:20Z

@TheShermanTanker Good point. You are correct; they should not have been there (to follow our style), but they should be harmless (I assume @swesonga tested that it still works with x64).

swesonga · 2025-08-27T00:47:48Z

I actually missed this earlier, but I don't believe the quotes around -Ta are needed. It doesn't seem to do any harm though, so I'm not sure if anyone else would want to remove them

Thanks for catching this. I've filed https://bugs.openjdk.org/browse/JDK-8366195 to clean it up

swesonga · 2025-08-27T00:49:50Z

@TheShermanTanker Good point. You are correct; they should not have been there (to follow our style), but they should be harmless (I assume @swesonga tested that it still works with x64).

Yes, it still works with x64. I'll clean up the quotes in https://bugs.openjdk.org/browse/JDK-8366195 though

swesonga added 2 commits August 14, 2025 09:42

Use armasm64.exe as the assembler for Windows aarch64

7e6568f

Remove -Ta flag

164bef5

openjdk bot added build build-dev@openjdk.org rfr Pull request is ready for review labels Aug 15, 2025

TheShermanTanker approved these changes Aug 15, 2025

View reviewed changes

erikj79 reviewed Aug 15, 2025

View reviewed changes

Reduce nesting levels

2ae8f30

TheShermanTanker approved these changes Aug 15, 2025

View reviewed changes

erikj79 approved these changes Aug 15, 2025

View reviewed changes

openjdk bot added the ready Pull request is ready to be integrated label Aug 15, 2025

openjdk bot added the sponsor Pull request is ready to be sponsored label Aug 15, 2025

sendaoYan reviewed Aug 18, 2025

View reviewed changes

Update the copyright year

3470f00

openjdk bot removed sponsor Pull request is ready to be sponsored ready Pull request is ready to be integrated labels Aug 18, 2025

Restore -Ta flag for x64 assembler

4279637

magicus approved these changes Aug 25, 2025

View reviewed changes

openjdk bot added the ready Pull request is ready to be integrated label Aug 25, 2025

TheShermanTanker approved these changes Aug 25, 2025

View reviewed changes

openjdk bot added the sponsor Pull request is ready to be sponsored label Aug 25, 2025

openjdk bot added the integrated Pull request has been integrated label Aug 26, 2025

openjdk bot closed this Aug 26, 2025

openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review sponsor Pull request is ready to be sponsored labels Aug 26, 2025

swesonga mentioned this pull request Aug 30, 2025

8366195: Remove unnecessary quotes around -Ta ml64 assembler argument #27021

Closed

3 tasks

8365579: ml64.exe is not the right assembler for Windows aarch64 #26791

8365579: ml64.exe is not the right assembler for Windows aarch64 #26791

Uh oh!

Conversation

swesonga commented Aug 14, 2025 • edited by openjdk bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Progress

Issue

Reviewers

Reviewing

Uh oh!

bridgekeeper bot commented Aug 15, 2025

Uh oh!

openjdk bot commented Aug 15, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

openjdk bot commented Aug 15, 2025

Uh oh!

mlbridge bot commented Aug 15, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Webrevs

Uh oh!

TheShermanTanker left a comment

Choose a reason for hiding this comment

Uh oh!

erikj79 Aug 15, 2025

Choose a reason for hiding this comment

Uh oh!

swesonga Aug 15, 2025

Choose a reason for hiding this comment

Uh oh!

TheShermanTanker Aug 15, 2025

Choose a reason for hiding this comment

Uh oh!

swesonga Aug 18, 2025

Choose a reason for hiding this comment

Uh oh!

magicus Aug 20, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

erikj79 Aug 15, 2025

Choose a reason for hiding this comment

Uh oh!

TheShermanTanker left a comment

Choose a reason for hiding this comment

Uh oh!

swesonga commented Aug 15, 2025

Uh oh!

openjdk bot commented Aug 15, 2025

Uh oh!

sendaoYan Aug 18, 2025

Choose a reason for hiding this comment

Uh oh!

erikj79 Aug 18, 2025

Choose a reason for hiding this comment

Uh oh!

magicus commented Aug 23, 2025

Uh oh!

magicus left a comment

Choose a reason for hiding this comment

Uh oh!

swesonga commented Aug 25, 2025

Uh oh!

openjdk bot commented Aug 25, 2025

Uh oh!

sendaoYan commented Aug 26, 2025

Uh oh!

openjdk bot commented Aug 26, 2025

Uh oh!

openjdk bot commented Aug 26, 2025

Uh oh!

TheShermanTanker commented Aug 26, 2025

Uh oh!

magicus commented Aug 26, 2025

Uh oh!

swesonga commented Aug 27, 2025

Uh oh!

swesonga commented Aug 27, 2025

Uh oh!

swesonga commented Aug 14, 2025 •

edited by openjdk bot

Loading

openjdk bot commented Aug 15, 2025 •

edited

Loading

mlbridge bot commented Aug 15, 2025 •

edited

Loading

magicus Aug 20, 2025 •

edited

Loading