8370569: IGV: dump more graph properties at bytecode parsing #27975

robcasloz · 2025-10-24T12:22:11Z

This changeset makes it easier to trace C2's individual bytecode parsing steps to the input class files and the output of type flow analysis, by:

dumping the map node (holding the JVM state), basic block (reverse post-order index), and method name as properties of the graph that C2 dumps after each parsed bytecode at IGV dump level 6;
appending this information to the graph name (hence generalizing JDK-8356779); and
making the graph name suffix configurable via Options -> Graph Name Suffix. By default, it appends (map: [map], block #[block] at [method]) to the names of graphs containing these properties (bytecode parsing dumps), and nothing otherwise.

Here are the Outline and Properties windows for

$ java -Xbatch -XX:CompileOnly=java.lang.String::charAt -XX:PrintIdealGraphLevel=6

before (left) and after (right) the changeset:

Please let me know if there are other bytecode parsing graph properties that could be useful to dump, and whether you think the default graph name suffix contains the right amount of information.

Testing

tier1.
Tested automatically that dumping thousands of graphs does not trigger any assertion failure on HotSpot or IGV.

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-8370569: IGV: dump more graph properties at bytecode parsing (Enhancement - P4)

Reviewers

Christian Hagedorn (@chhagedorn - Reviewer)
Saranya Natarajan (@sarannat - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/27975/head:pull/27975
$ git checkout pull/27975

Update a local copy of the PR:
$ git checkout pull/27975
$ git pull https://git.openjdk.org/jdk.git pull/27975/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 27975

View PR using the GUI difftool:
$ git pr show -t 27975

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/27975.diff

Using Webrev

Link to Webrev Comment

bridgekeeper · 2025-10-24T12:23:48Z

👋 Welcome back rcastanedalo! 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 · 2025-10-24T12:23:51Z

@robcasloz 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:

8370569: IGV: dump more graph properties at bytecode parsing

Reviewed-by: chagedorn, snatarajan

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 173 new commits pushed to the master branch:

19920df: 8370417: Parallel: TestAlwaysPreTouchBehavior.java fails with NUMA
9625993: 8370579: PPC: fix inswri immediate argument order
f82cc22: 8369428: Include method name in 'does not override or implement' diagnostics
... and 170 more: https://git.openjdk.org/jdk/compare/b5b83247da9caea30c88b69543e350783663bc46...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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

openjdk · 2025-10-24T12:24:35Z

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

hotspot-compiler

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 · 2025-10-24T12:33:37Z

Webrevs

chhagedorn

Nice improvement! I tried your patch out and I sometimes see a missing index for map. That might be expected but when looking at it, it rather suggests that something is off. If there is no map, maybe we can use "none" or completely remove the "map" entry for that graph.

chhagedorn · 2025-10-27T08:11:28Z

...tils/IdealGraphVisualizer/Settings/src/main/java/com/sun/hotspot/igv/settings/ViewPanel.java

+    private void graphNameSuffixFieldActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_graphNameSuffixFieldActionPerformed
+        // TODO add your handling code here:
+    }//GEN-LAST:event_graphNameSuffixFieldActionPerformed


Can you explain why this nop-action is needed?

Good catch. It is not needed, just the result of some spurious clicking on the NetBeans form editor that resulted in that code being auto-generated. I removed the action declaration and other GUI properties of the new text field to align the generated code with that of the other text fields in the Options form (commit 4123bb0).

Can this method then be removed?

Right, sorry, removed now (commit 8da5897). I was expecting that NetBeans would detect it as dead and remove it automagically when re-generating ViewPanel.java from ViewPanel.form, but forgot to check.

No worries! Thanks for cleaning it up, it looks good to me now 👍

…xt field

robcasloz · 2025-10-27T10:20:58Z

I tried your patch out and I sometimes see a missing index for map. That might be expected but when looking at it, it rather suggests that something is off. If there is no map, maybe we can use "none" or completely remove the "map" entry for that graph.

It is expected, but I agree that the presentation could be improved. I went with printing - if there is no map, for compactness (commit 050fe0d), but I am OK with changing it to none if you think that is better.

robcasloz · 2025-10-27T10:25:35Z

Thanks for the review, Christian! I just addressed your comments, please let me know what you think about the new version.

chhagedorn

Looks good, thanks!

chhagedorn · 2025-10-27T14:16:39Z

...tils/IdealGraphVisualizer/Settings/src/main/java/com/sun/hotspot/igv/settings/ViewPanel.java

+    private void graphNameSuffixFieldActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_graphNameSuffixFieldActionPerformed
+        // TODO add your handling code here:
+    }//GEN-LAST:event_graphNameSuffixFieldActionPerformed


Can this method then be removed?

sarannat

Thank you for the improvement. I have tested some random programs and the changes look good.

robcasloz · 2025-10-28T12:23:27Z

Thank you for the improvement. I have tested some random programs and the changes look good.

Thanks for reviewing, Saranya! @chhagedorn I removed the dead code you referred to, are you happy with the current version?

robcasloz · 2025-10-28T12:35:23Z

Thanks for reviewing, Christian!

robcasloz · 2025-10-28T13:30:41Z

/integrate

openjdk · 2025-10-28T13:31:17Z

Going to push as commit 5c5367c.
Since your change was applied there have been 174 commits pushed to the master branch:

307637a: 8370806: Parallel: Revise logs in PSYoungGen::compute_desired_sizes
19920df: 8370417: Parallel: TestAlwaysPreTouchBehavior.java fails with NUMA
9625993: 8370579: PPC: fix inswri immediate argument order
... and 171 more: https://git.openjdk.org/jdk/compare/b5b83247da9caea30c88b69543e350783663bc46...master

Your commit was automatically rebased without conflicts.

openjdk · 2025-10-28T13:31:28Z

@robcasloz Pushed as commit 5c5367c.

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

Initial commit

49ee574

openjdk bot added the hotspot-compiler hotspot-compiler-dev@openjdk.org label Oct 24, 2025

robcasloz marked this pull request as ready for review October 24, 2025 12:29

openjdk bot added the rfr Pull request is ready for review label Oct 24, 2025

chhagedorn reviewed Oct 27, 2025

View reviewed changes

robcasloz added 2 commits October 27, 2025 10:04

Use '-' for non-existing maps

050fe0d

Simplify code generated by NetBeans for the 'graphNameSuffixField' te…

4123bb0

…xt field

chhagedorn approved these changes Oct 27, 2025

View reviewed changes

openjdk bot added the ready Pull request is ready to be integrated label Oct 27, 2025

Remove leftover from NetBeans code generation

8da5897

openjdk bot removed the ready Pull request is ready to be integrated label Oct 27, 2025

robcasloz requested a review from chhagedorn October 27, 2025 15:51

sarannat reviewed Oct 28, 2025

View reviewed changes

sarannat approved these changes Oct 28, 2025

View reviewed changes

chhagedorn approved these changes Oct 28, 2025

View reviewed changes

openjdk bot added the ready Pull request is ready to be integrated label Oct 28, 2025

openjdk bot added the integrated Pull request has been integrated label Oct 28, 2025

openjdk bot closed this Oct 28, 2025

openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Oct 28, 2025

Uh oh!

8370569: IGV: dump more graph properties at bytecode parsing #27975

8370569: IGV: dump more graph properties at bytecode parsing #27975

Uh oh!

Conversation

robcasloz commented Oct 24, 2025 • edited by openjdk bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Testing

Progress

Issue

Reviewers

Reviewing

Uh oh!

bridgekeeper bot commented Oct 24, 2025

Uh oh!

openjdk bot commented Oct 24, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

openjdk bot commented Oct 24, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

mlbridge bot commented Oct 24, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Webrevs

Uh oh!

chhagedorn left a comment

Choose a reason for hiding this comment

Uh oh!

chhagedorn Oct 27, 2025

Choose a reason for hiding this comment

Uh oh!

robcasloz Oct 27, 2025

Choose a reason for hiding this comment

Uh oh!

chhagedorn Oct 27, 2025

Choose a reason for hiding this comment

Uh oh!

robcasloz Oct 27, 2025

Choose a reason for hiding this comment

Uh oh!

chhagedorn Oct 28, 2025

Choose a reason for hiding this comment

Uh oh!

robcasloz commented Oct 27, 2025

Uh oh!

robcasloz commented Oct 27, 2025

Uh oh!

chhagedorn left a comment

Choose a reason for hiding this comment

Uh oh!

chhagedorn Oct 27, 2025

Choose a reason for hiding this comment

Uh oh!

sarannat left a comment

Choose a reason for hiding this comment

Uh oh!

robcasloz commented Oct 28, 2025

Uh oh!

robcasloz commented Oct 28, 2025

Uh oh!

robcasloz commented Oct 28, 2025

Uh oh!

openjdk bot commented Oct 28, 2025

Uh oh!

openjdk bot commented Oct 28, 2025

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

3 participants

robcasloz commented Oct 24, 2025 •

edited by openjdk bot

Loading

openjdk bot commented Oct 24, 2025 •

edited

Loading

openjdk bot commented Oct 24, 2025 •

edited

Loading

mlbridge bot commented Oct 24, 2025 •

edited

Loading