8305236: Some LoadLoad barriers in the interpreter are unnecessary after JDK-8220051

[shipilev]

Semi-clean backport to improve AArch64 cold start performance. The backport is not clean, because RISC-V port is not in 17u, and so those hunks do not apply.

Additional testing:

• Ad-hoc targeted benchmark from the RFE improves
• Linux AArch64 fastdebug tier1 tier2 tier3

---

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-8305236: Some LoadLoad barriers in the interpreter are unnecessary after JDK-8220051 (Enhancement - P4)

Reviewers

• Paul Hohensee (@phohensee - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk17u-dev.git pull/1468/head:pull/1468
$ git checkout pull/1468

Update a local copy of the PR:
$ git checkout pull/1468
$ git pull https://git.openjdk.org/jdk17u-dev.git pull/1468/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 1468

View PR using the GUI difftool:
$ git pr show -t 1468

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk17u-dev/pull/1468.diff

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[bridgekeeper]

👋 Welcome back shade! 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]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 00: Full (f428dca8)

[phohensee]

Lgtm.

[openjdk]

@shipilev 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:

8305236: Some LoadLoad barriers in the interpreter are unnecessary after JDK-8220051

Reviewed-by: phh

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 25 new commits pushed to the master branch:

• 6c81bf5: 8295811: serviceability/sa/TestObjectAlignment.java fails on x86_32
• c6f6db2: 8295657: SA: Allow larger object alignments
• 55c0eaa: 8272654: Mark word accesses should not use Access API
• 7697ab4: 8309550: jdk.jfr.internal.Utils::formatDataAmount method should gracefully handle amounts equal to Long.MIN_VALUE
• 852c26c: 8279545: Buffer overrun in reverse_words of sharedRuntime_x86_64.cpp:3517
• 5fc07b5: 8305815: Update Libpng to 1.6.39
• 9dd23ff: 8292315: Tests should not rely on specific JAR file names (hotspot)
• f21f9a4: 8292316: Tests should not rely on specific JAR file names (jpackage)
• 01369a6: 8285756: clean up use of bad arguments for @clean in langtools tests
• 4bbead6: 8286620: Create regression test for verifying setMargin() of JRadioButton
• ... and 15 more: https://git.openjdk.org/jdk17u-dev/compare/6991372a06f7e623112f1437eeaed7ad7eb6eb99...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.

[shipilev]

Testing is clean. Reviews are done. Push approval is here.

/integrate

[openjdk]

Going to push as commit aa3b4e4.
Since your change was applied there have been 32 commits pushed to the master branch:

• bda6723: 8282665: [REDO] ByteBufferTest.java: replace endless recursion with RuntimeException in void ck(double x, double y)
• 393aeaf: 8272586: emit abstract machine code in hs-err logs
• d85a847: 8289688: jfr command hangs when it processes invalid file
• 9780137: 8286481: Exception printed to stdout on Windows when storing transparent image in clipboard
• 0368ae9: 8306738: Select num workers for safepoint ParallelCleanupTask
• 249ddf4: 8293252: Shenandoah: ThreadMXBean synchronizer tests crash with aggressive heuristics
• 5a4e374: 8309959: JFR: Display N/A for missing data amount
• 6c81bf5: 8295811: serviceability/sa/TestObjectAlignment.java fails on x86_32
• c6f6db2: 8295657: SA: Allow larger object alignments
• 55c0eaa: 8272654: Mark word accesses should not use Access API
• ... and 22 more: https://git.openjdk.org/jdk17u-dev/compare/6991372a06f7e623112f1437eeaed7ad7eb6eb99...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit aa3b4e4.

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