8345299: C2: some nodes can still have incorrect control after do_range_check() #22485

rwestrel · 2024-12-02T13:53:00Z

8339733 fixed controls for updated pre/main limits during
do_range_check(). However, it missed one issue:

Control for the new limits is computed in new_limit_ctrl for both
pre and main loops. new_limit_ctrl is currently initialized from the
pre limit control but it also needs to take the main loop limit
control into account as sometimes, the main loop limit control is
below the pre limit and pre loop entry control.

8339733 also introduced a couple bugs. Control of the Bool/Cmp
nodes are updated for the pre and main loop to new_limit_ctrl. But
that's incorrect because new_limit_ctrl may be above the pre loop
while the Bool/Cmp for the pre loop are in the loop (because they
depend on the loop iv) and for the main loop are after the pre loop
(because they depend on the iv out of the pre loop). I fixed this for
the pre loop by setting control for the Bool/Cmp to be as late as
possible. For the main loop, no change appears to be required as
control computed by c2 is already late enough. I've added an assert
instead.

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-8345299: C2: some nodes can still have incorrect control after do_range_check() (Bug - P4)

Reviewers

Christian Hagedorn (@chhagedorn - Reviewer)
Vladimir Kozlov (@vnkozlov - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/22485/head:pull/22485
$ git checkout pull/22485

Update a local copy of the PR:
$ git checkout pull/22485
$ git pull https://git.openjdk.org/jdk.git pull/22485/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 22485

View PR using the GUI difftool:
$ git pr show -t 22485

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/22485.diff

Using Webrev

Link to Webrev Comment

bridgekeeper · 2024-12-02T13:54:05Z

👋 Welcome back roland! 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 · 2024-12-02T13:54:55Z

@rwestrel 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:

8345299: C2: some nodes can still have incorrect control after do_range_check()

Reviewed-by: chagedorn, kvn

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 158 new commits pushed to the master branch:

5cc150c: 8342979: Start of release updates for JDK 25
85fedbf: 8344607: Link Time Optimization - basic support for clang
5a0899f: 8345302: Building microbenchmarks require larger Java heap
1ece4f9: 8345514: Should use internal class name when calling ClassLoader.getResourceAsByteArray
ef8da28: 8345591: [aarch64] macroAssembler_aarch64.cpp compile fails ceil_log2 not declared
7513b13: 8328944: NMT reports "unknown" memory
691e692: 8345565: Remove remaining SecurityManager motivated APIs from sun.reflect.util
97b8a09: 8345339: JFR: Missing javadoc for RecordingStream::onMetadata
456c71d: 8343699: [aarch64] Bug in MacroAssembler::klass_decode_mode()
308357c: 8345578: New test in JDK-8343622 fails with a promoted build
... and 148 more: https://git.openjdk.org/jdk/compare/3b21a298c29d88720f6bfb2dc1f3305b6a3db307...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 · 2024-12-02T13:55:41Z

@rwestrel 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 · 2024-12-02T14:01:11Z

Webrevs

01: Full - Incremental (0b08402d)
00: Full (e7904f6c)

chhagedorn

Looks good to me. Do you have a regression test where this leads to an actual failure?

rwestrel · 2024-12-03T12:50:38Z

Looks good to me. Do you have a regression test where this leads to an actual failure?

I don't. This seems unlikely to cause issues with the current code. I ran into this while working on JDK-8275202 where new code I've added is failing.

chhagedorn · 2024-12-03T13:43:39Z

I see, thanks for background!

vnkozlov

Few comments.

vnkozlov · 2024-12-03T17:08:28Z

src/hotspot/share/opto/loopTransform.cpp

  // new pre_limit can push Bool/Cmp/Opaque nodes down (when one of the eliminated condition has parameters that are not
  // loop invariant in the pre loop.
  set_ctrl(pre_opaq, new_limit_ctrl);


Can you update this comment to explain different control settings as you did in PR's description.

vnkozlov · 2024-12-03T17:14:28Z

src/hotspot/share/opto/loopTransform.cpp

  // new main_limit can push Bool/Cmp nodes down (when one of the eliminated condition has parameters that are not loop
-  // invariant in the pre loop.
+  // invariant in the pre loop).
  set_ctrl(opqzm, new_limit_ctrl);


Update this comment too.

Both done in new commit. Do the comments look ok to you?

vnkozlov

Good.

rwestrel · 2024-12-06T09:18:12Z

@vnkozlov @chhagedorn thanks for the reviews

rwestrel · 2024-12-06T09:18:24Z

/integrate

openjdk · 2024-12-06T09:18:49Z

Going to push as commit d9a2213.
Since your change was applied there have been 171 commits pushed to the master branch:

2286fae: 8345159: RISCV: Fix -Wzero-as-null-pointer-constant warning in emit_static_call_stub
8403285: 8268145: [macos] Rendering artifacts is seen when text inside the JTable with TableCellEditor having JTextfield
aa38284: 8345435: Eliminate tier1_compiler_not_xcomp group
9284602: 8345628: [BACKOUT] JDK-8287122 Use gcc12 -ftrivial-auto-var-init=pattern in debug builds
41c8971: 8287122: Use gcc12 -ftrivial-auto-var-init=pattern in debug builds
5da0eee: 8285692: Enable _FORTIFY_SOURCE=2 when building with Clang
daa2ba5: 8339622: Regression in make open-hotspot-xcode-project
6f6bce5: 8344559: Log is spammed by missing pandoc warnings when building man pages
5f30a8d: 8345424: Move FindDebuginfoFiles out of FileUtils.gmk
bf0debc: 8343890: SEGV crash in RunTimeClassInfo::klass
... and 161 more: https://git.openjdk.org/jdk/compare/3b21a298c29d88720f6bfb2dc1f3305b6a3db307...master

Your commit was automatically rebased without conflicts.

openjdk · 2024-12-06T09:18:58Z

@rwestrel Pushed as commit d9a2213.

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

fix

6082db5

rwestrel marked this pull request as draft December 2, 2024 13:53

openjdk bot added the hotspot-compiler hotspot-compiler-dev@openjdk.org label Dec 2, 2024

comment

e7904f6

rwestrel marked this pull request as ready for review December 2, 2024 13:56

openjdk bot added the rfr Pull request is ready for review label Dec 2, 2024

chhagedorn approved these changes Dec 3, 2024

View reviewed changes

openjdk bot added the ready Pull request is ready to be integrated label Dec 3, 2024

vnkozlov reviewed Dec 3, 2024

View reviewed changes

review

0b08402

openjdk bot removed the ready Pull request is ready to be integrated label Dec 4, 2024

vnkozlov approved these changes Dec 4, 2024

View reviewed changes

openjdk bot added the ready Pull request is ready to be integrated label Dec 4, 2024

chhagedorn approved these changes Dec 5, 2024

View reviewed changes

openjdk bot added the integrated Pull request has been integrated label Dec 6, 2024

openjdk bot closed this Dec 6, 2024

openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Dec 6, 2024

8345299: C2: some nodes can still have incorrect control after do_range_check() #22485

8345299: C2: some nodes can still have incorrect control after do_range_check() #22485

Uh oh!

Conversation

rwestrel commented Dec 2, 2024 • 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 Dec 2, 2024

Uh oh!

openjdk bot commented Dec 2, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

openjdk bot commented Dec 2, 2024

Uh oh!

mlbridge bot commented Dec 2, 2024 • 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!

rwestrel commented Dec 3, 2024

Uh oh!

chhagedorn commented Dec 3, 2024

Uh oh!

vnkozlov left a comment

Choose a reason for hiding this comment

Uh oh!

vnkozlov Dec 3, 2024

Choose a reason for hiding this comment

Uh oh!

vnkozlov Dec 3, 2024

Choose a reason for hiding this comment

Uh oh!

rwestrel Dec 4, 2024

Choose a reason for hiding this comment

Uh oh!

vnkozlov Dec 4, 2024

Choose a reason for hiding this comment

Uh oh!

vnkozlov left a comment

Choose a reason for hiding this comment

Uh oh!

rwestrel commented Dec 6, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rwestrel commented Dec 6, 2024

Uh oh!

openjdk bot commented Dec 6, 2024

Uh oh!

openjdk bot commented Dec 6, 2024

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

3 participants

rwestrel commented Dec 2, 2024 •

edited by openjdk bot

Loading

openjdk bot commented Dec 2, 2024 •

edited

Loading

mlbridge bot commented Dec 2, 2024 •

edited

Loading

rwestrel commented Dec 6, 2024 •

edited

Loading