RFR: 8358534: Bailout in Conv2B::Ideal when type of cmp input is not supported

[Emanuel Peter]

On Tue, 3 Jun 2025 19:48:37 GMT, Cesar Soares Lucas <cslucas at openjdk.org> wrote:

> `Conv2BNode::ideal` segfaults in release builds when the type of `in(1)` is not INT or PTR. Creating a small test case to reproduce the issue is being a bit challenging so this PR only address the issue by bailing out of the method if the input type is unsupported. This other ticket https://bugs.openjdk.org/browse/JDK-8357885 will address creating a regression test for the problem.
> 
> Tested with JTREG tier1-3 and Renaissance on Linux x64.

@JohnTortugo If you integrate before 24h, you need to explicitly say that it is trivial, and the reviewer needs to agree.

We in europe were sleeping and did not even have a chance to look at it.

src/hotspot/share/opto/convertnode.cpp line 86:

> 84:         return nullptr;
> 85:       }
> 86: 

@JohnTortugo Would it not have been better to put this check inside the `else` branch?

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PR Review: https://git.openjdk.org/jdk/pull/25627#pullrequestreview-2895442512
PR Review Comment: https://git.openjdk.org/jdk/pull/25627#discussion_r2125783037