8275610: C2: Object field load floats above its null check resulting in a segfault

[GoeLin]

I backport this for parity with 11.0.15-oracle.

I had to adapt the test.
@key randomness is not supported in 11, as are -XX:StressSeed=42 and -XX:+StressIGVN.
I removed these. This makes the second @run call superfluous.

Still, the test crashes the VM without the fix.

---

Progress

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Issue

• JDK-8275610: C2: Object field load floats above its null check resulting in a segfault

Reviewers

• Paul Hohensee (@phohensee - Reviewer) ⚠️ Review applies to 9cf7f6f

Reviewing

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Checkout this PR locally:
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$ git checkout pull/784

Update a local copy of the PR:
$ git checkout pull/784
$ git pull https://git.openjdk.java.net/jdk11u-dev pull/784/head

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Checkout this PR locally:
$ git pr checkout 784

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https://git.openjdk.java.net/jdk11u-dev/pull/784.diff

[bridgekeeper]

👋 Welcome back goetz! 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

• 01: Full (8b4d8790)
• 00: Full (9cf7f6fc)

[phohensee]

Lgtm.

[openjdk]

@GoeLin This change now passes all automated pre-integration checks.

After integration, the commit message for the final commit will be:

8275610: C2: Object field load floats above its null check resulting in a segfault

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 no new commits pushed to the master branch. If another commit should be pushed before you perform the /integrate command, your PR will be automatically rebased. If you prefer to avoid any potential automatic rebasing, please check the documentation for the /integrate command for further details.

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[GoeLin]

Finally the Pre-submit tests are green. Before, a hand ful of jdi test had failed.
While this was likely unrelated, I forced a re-tests anyways.

[GoeLin]

/integrate

[openjdk]

Going to push as commit efe46bb.
Since your change was applied there have been 5 commits pushed to the master branch:

• 716ceb7: 8266421: Deadlock in Sound System
• b5cae57: 8274795: AArch64: avoid spilling and restoring r18 in macro assembler
• 914d48c: 8232533: G1 uses only a single thread for pretouching the java heap
• ec03928: 8273933: [TESTBUG] Test must run without preallocated exceptions
• cba6c04: 8268542: serviceability/logging/TestFullNames.java tests only 1st test case

Your commit was automatically rebased without conflicts.

[openjdk]

@GoeLin Pushed as commit efe46bb.

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