RFR: 8343774: compiler/c2/TestCastX2NotProcessedIGVN.java fails on ppc64(le) & s390x platforms

[Richard Reingruber]

On Sat, 9 Nov 2024 03:41:56 GMT, Amit Kumar <amitkumar at openjdk.org> wrote:

>>> Thanks for taking care of that. Maybe it would be more robust to only enable the test on x86, aarch64 and riscv64. The whole test doesn't need to excluded actually. Only IR matching on `test2` needs to be disabled. This can be done with:
>>> 
>>> ```
>>> applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
>>> ```
>>> 
>>> See `TestBoolNodeGVN.java` for instance.
>> 
>> Ok. I've done that.
>
> @reinrich Sorry for creating mess here.
> 
> Yesterday, this test failed while testing changes for JEP 450 related to compact headers. However, now I checked and head stream testing job shows that it does not fail with `jdk-head`;
> 
>  I have verified and It fails only on s390x when I enable UseCompactObjectHeaders:  `make test TEST=jtreg:$(find . -name TestCastX2NotProcessedIGVN.java) JTREG="VM_OPTIONS=-XX:+UnlockExperimentalVMOptions -XX:+UseCompactObjectHeaders"`.
> 
> While this issue could potentially occur with other settings, `UseCompactObjectHeaders` is the only one I have observed causing this failure. Do you suggest disabling this, or is separate debugging required to investigate this behaviour?"

It's really up to you @offamitkumar. For PPC we have opened an internal bug (actually it should be mirrored by a JBS-issue) to revise the compilation of `test2`.

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PR Comment: https://git.openjdk.org/jdk/pull/21975#issuecomment-2467401535