RFR: 8343380: C2: assert(iff->in(1)->is_OpaqueNotNull()) failed: must be OpaqueNotNull

[Christian Hagedorn]

On Thu, 31 Oct 2024 12:27:45 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> The assert added in [JDK-8342043](https://bugs.openjdk.org/browse/JDK-8342043) turns out to be too strong as shown with the test cases. I was unsure about that in the first place when I added it here:
> 
> https://github.com/openjdk/jdk/pull/21608#discussion_r1808732859
> 
> The assert was more of a best guess and just an additional guarantee that does not provide any benefit. I've found two cases where we have once an `OuterStripMinedLoopEnd` node and once a `ParsePredicate` in `ConnectionGraph::can_reduce_check_users()` which trigger the assert. How we end up with such a graph is explained in the comments at the test cases. 
> 
> I don't think it's worth to tweak the assert as we simply bail out afterwards anyway. I therefore propose to simply get rid of the assert again.
> 
> Thanks,
> Christian

Thanks Vladimir for your review!

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PR Comment: https://git.openjdk.org/jdk/pull/21805#issuecomment-2451395078