RFR: JDK-8316756: C2 EA fails with "missing memory path" when encountering unsafe_arraycopy stub call

[Vladimir Kozlov]

On Fri, 12 Jan 2024 15:44:21 GMT, Tobias Holenstein <tholenstein at openjdk.org> wrote:

>>> Flag setting (StoreB nodes) in JavaThread::_doing_unsafe_access is also not affected but it is volatile field and these stores should be staying where they are. They can't go up or down.
>> 
>> In a private discussion with @tobiasholenstein, I proposed to move those stores into the corresponding stub. It would complicate the implementation a bit (platform-specific vs cross-platform implementation), but simplify things on IR level.
>
>> > Flag setting (StoreB nodes) in JavaThread::_doing_unsafe_access is also not affected but it is volatile field and these stores should be staying where they are. They can't go up or down.
>> 
>> In a private discussion with @tobiasholenstein, I proposed to move those stores into the corresponding stub. It would complicate the implementation a bit (platform-specific vs cross-platform implementation), but simplify things on IR level.
> 
> So you think we should go for that solution instead of this fix?

@tobiasholenstein  I suggest to file separate REF to move StoreB which updates `JavaThread::_doing_unsafe_access` into stub and work on it.

For this issue we need to fix EA. I will work on patch.

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PR Comment: https://git.openjdk.org/jdk/pull/17347#issuecomment-1889874468