RFR: 8365047: Remove exception handler stub code in C2 [v2]

[Ruben]

On Thu, 14 Aug 2025 08:56:19 GMT, Ruben <duke at openjdk.org> wrote:

>> The C2 exception handler stub code is only a trampoline to the generated exception handler blob. This change removes the extra step on the way to the generated blob.
>> 
>> According to some comments in the source code, the exception handler stub code used to be patched upon deoptimization, however presumably these comments are outdated as the patching upon deoptimization happens for post-call NOPs only.
>
> Ruben has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Address review comments

Thanks for the feedback, I've updated the change.

>> I've run tier1-tier3 tests, however only on AArch64 and x86-64.
>> I can run more tests on these platforms if that might be useful.

> As you've touched a few other platforms' files it might be a good idea (to be on the safe-side).

To clarify my earlier comment: when I said "I can run more tests on these platforms if that might be useful.", I meant more testing on AArch64 and x86-64 only. I don't have any other platform available for testing.

Does the testing infrastructure on the Github/CI provide a way to run the tests on other platforms by any chance?

Otherwise, to stay on the safe side, I could revert the change for the platforms other than AArch64 and x86-64.

Please let me know which path you prefer.

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PR Comment: https://git.openjdk.org/jdk/pull/26678#issuecomment-3187709818