8265587: IGV: track nodes across matching #3654

robcasloz · 2021-04-23T12:31:20Z

This change preserves, as much as possible, the IGV node identifier of Ideal nodes in their corresponding machine nodes created by Matcher::match(). This makes it possible to track nodes when stepping from "Before matching" to "After matching" in IGV, as illustrated for an extracted compare-and-branch subgraph in the following screenshot:

Limitations

This solution preserves most of the node relations across matching, however if an Ideal node is expanded into multiple machine nodes, only one of them is assigned the IGV identifier of the Ideal node (since IGV identifiers need to be unique within a compilation phase). This limitation can be seen in the following example, where the CmpU Ideal node is implemented with three compU_rReg machine nodes (one for each jmpConU machine node), but only one of the compU_rReg machine nodes (50) preserves the IGV identifier:

Overcoming this limitation would require explicitly serializing the entire before-after relation among nodes and adapting IGV's node selection and graph difference logic, which seems too complex for a relatively infrequent case.

Testing

Regression-tested HotSpot changes on hs-tier1-3, windows-x64, linux-x64, linux-aarch64, and macosx-x64 (both release and debug).
Tested HotSpot graph generation and IGV graph loading and scheduling on tens of thousands of graphs by running java -Xcomp -XX:-TieredCompilation -XX:PrintIdealGraphLevel=4 ... on an instrumented IGV. Loading and scheduling are useful graph well-formedness tests, as they tend to fail for incorrect graphs, e.g. with repeated node identifiers.
Tested manually, for a few graphs, that nodes of different types can be tracked across matching.

Progress

Change must not contain extraneous whitespace
Commit message must refer to an issue
Change must be properly reviewed

Issue

JDK-8265587: IGV: track nodes across matching

Reviewers

Tobias Hartmann (@TobiHartmann - Reviewer)
Vladimir Ivanov (@iwanowww - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/3654/head:pull/3654
$ git checkout pull/3654

Update a local copy of the PR:
$ git checkout pull/3654
$ git pull https://git.openjdk.java.net/jdk pull/3654/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 3654

View PR using the GUI difftool:
$ git pr show -t 3654

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/3654.diff

bridgekeeper · 2021-04-23T12:32:10Z

👋 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 · 2021-04-23T12:33:56Z

@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 · 2021-04-23T12:45:50Z

Webrevs

00: Full (216083fa)

TobiHartmann

That's a nice enhancement, looks good to me!

openjdk · 2021-04-27T09:38:32Z

@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:

8265587: IGV: track nodes across matching

Preserve the IGV node identifier of Ideal nodes in their corresponding machine
nodes after matching, to allow IGV users to track nodes across this phase.

Reviewed-by: thartmann, vlivanov

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 94 new commits pushed to the master branch:

164454f: 8265867: thread.hpp defines some enums but no reference
75a2354: 8266028: C2 computes -0.0 for Math.pow(-0.0, 0.5)
ca37be1: 8197800: Test java/awt/Focus/NonFocusableWindowTest/NoEventsTest.java fails on Windows
cf92693: 8198619: java/awt/Focus/FocusTraversalPolicy/ButtonGroupLayoutTraversal/ButtonGroupLayoutTraversalTest.java fails on mac
2201e11: 8266055: ZGC: ZHeap::print_extended_on() doesn't disable deferred delete
ce48f04: 8198617: java/awt/Focus/6382144/EndlessLoopTest.java fails on mac
0438cea: 8136517: [macosx]Test java/awt/Focus/8073453/AWTFocusTransitionTest.java fails on MacOSX
6b5e5d7: 8266181: compiler/eliminateAutobox/TestEliminateBoxInDebugInfo should be in driver mode
81b1502: 8266161: mark hotspot compiler/rtm tests which ignore VM flags
4a8324d: 8266180: compiler/vectorapi/TestVectorErgonomics should be run in driver mode
... and 84 more: https://git.openjdk.java.net/jdk/compare/b3a319c83441a8707fc4ddd1dc6a09d3de3097ac...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.

robcasloz · 2021-04-27T10:01:23Z

That's a nice enhancement, looks good to me!

Thanks for reviewing, Tobias!

iwanowww

Looks good.

robcasloz · 2021-04-27T17:26:28Z

Looks good.

Thanks Vladimir!

robcasloz · 2021-04-28T08:40:58Z

/summary
Preserve the IGV node identifier of Ideal nodes in their corresponding machine
nodes after matching, to allow IGV users to track nodes across this phase.

openjdk · 2021-04-28T08:41:39Z

@robcasloz Setting summary to:

Preserve the IGV node identifier of Ideal nodes in their corresponding machine
nodes after matching, to allow IGV users to track nodes across this phase.

robcasloz · 2021-04-28T08:43:55Z

/integrate

openjdk · 2021-04-28T08:45:34Z

@robcasloz Since your change was applied there have been 94 commits pushed to the master branch:

164454f: 8265867: thread.hpp defines some enums but no reference
75a2354: 8266028: C2 computes -0.0 for Math.pow(-0.0, 0.5)
ca37be1: 8197800: Test java/awt/Focus/NonFocusableWindowTest/NoEventsTest.java fails on Windows
cf92693: 8198619: java/awt/Focus/FocusTraversalPolicy/ButtonGroupLayoutTraversal/ButtonGroupLayoutTraversalTest.java fails on mac
2201e11: 8266055: ZGC: ZHeap::print_extended_on() doesn't disable deferred delete
ce48f04: 8198617: java/awt/Focus/6382144/EndlessLoopTest.java fails on mac
0438cea: 8136517: [macosx]Test java/awt/Focus/8073453/AWTFocusTransitionTest.java fails on MacOSX
6b5e5d7: 8266181: compiler/eliminateAutobox/TestEliminateBoxInDebugInfo should be in driver mode
81b1502: 8266161: mark hotspot compiler/rtm tests which ignore VM flags
4a8324d: 8266180: compiler/vectorapi/TestVectorErgonomics should be run in driver mode
... and 84 more: https://git.openjdk.java.net/jdk/compare/b3a319c83441a8707fc4ddd1dc6a09d3de3097ac...master

Your commit was automatically rebased without conflicts.

Pushed as commit e879f8c.

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

robcasloz added 2 commits April 23, 2021 10:35

Reuse Ideal-level IGV identifiers in machine nodes

0aa45bd

Refine description of Node::_igv_idx

216083f

openjdk bot added the hotspot-compiler hotspot-compiler-dev@openjdk.org label Apr 23, 2021

robcasloz marked this pull request as ready for review April 23, 2021 12:40

openjdk bot added the rfr Pull request is ready for review label Apr 23, 2021

TobiHartmann approved these changes Apr 27, 2021

View changes

openjdk bot added the ready Pull request is ready to be integrated label Apr 27, 2021

iwanowww approved these changes Apr 27, 2021

View changes

openjdk bot closed this Apr 28, 2021

openjdk bot added integrated Pull request has been integrated and removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Apr 28, 2021

8265587: IGV: track nodes across matching #3654

8265587: IGV: track nodes across matching #3654

robcasloz commented Apr 23, 2021 •

edited by openjdk bot

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openjdk bot commented Apr 27, 2021 •

edited

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robcasloz commented Apr 28, 2021

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robcasloz commented Apr 28, 2021

openjdk bot commented Apr 28, 2021

8265587: IGV: track nodes across matching #3654

8265587: IGV: track nodes across matching #3654

Conversation

robcasloz commented Apr 23, 2021 • edited by openjdk bot

Limitations

Testing

Progress

Issue

Reviewers

Reviewing

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openjdk bot commented Apr 27, 2021 • edited

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robcasloz commented Apr 23, 2021 •

edited by openjdk bot

openjdk bot commented Apr 27, 2021 •

edited