Verify and reenable testcases related to Backport for JDK-8311964: x86 bug 'unrecognized VM options' (C2 flags)

[adamfarley]

Summary

An upstream bug has been seen in JDK21 (and under) testing at Adoptium.

To solve this, we should request that the fix for that bug be backported.

Details

Adoptium test failures were documented here and here.

These tests were subsequently excluded here.

These failures look like they were caused by this OpenJDK bug.

We see that this bug has been fixed, and that the fix was merged into JDK22+.

To solve this problem at Adoptium, a backport was proposed in the General Retrospective for the Adoptium January 2024 releases.

[adamfarley]

Thanks Shelley :)

[jiekang]

Backport has been made to 21u and 17u by sendaoYan in February, see issue comments in link below:

https://bugs.openjdk.org/browse/JDK-8311964

[smlambert]

Changing the title to reflect the action now is to check that the test cases can be re-included.
related: #4965

[jiekang]

Noting for future investigator, the OpenJDK PR only mentions three tests:

Following tests were affected:
TestInfiniteLoopWithUnmergedBackedgesMain.java - Affected by 'LoopUnswitching'
TestBackedgeLoadArrayFillMain.java - Affected by 'OptimizeFill'
TestRangeCheckCmpUOverflowVsSub.java - Affected by 'StressCCP'

[jiekang]

Also just further checked, the PRs to backport have been opened but not approved or merged. Sorry.

openjdk/jdk21u-dev#279
openjdk/jdk17u-dev#2216

[sendaoYan]

Also just further checked, the PRs to backport have been opened but not approved or merged. Sorry.

openjdk/jdk21u-dev#279 openjdk/jdk17u-dev#2216

I will try to backport there two PRs as soon as quick possible.

[jiekang]

@sendaoYan

Ah, thank you for the update. And thanks for doing the work to backport those changes!

I did not mean to suggest they need to be done immediately. When you have time to do them is great!

[sendaoYan]

@sendaoYan

Ah, thank you for the update. And thanks for doing the work to backport those changes!

I did not mean to suggest they need to be done immediately. When you have time to do them is great!

OK.