RFR: 8367967: C2: "fatal error: Not monotonic" with Mod nodes

[Matthias Baesken]

On Wed, 24 Sep 2025 09:21:32 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> I'll  test this in our CI to see if this fixes the linux aarch64 issues (observed when running Test java/foreign/TestUpcallStress.java ) .
>
>> I'll test this in our CI to see if this fixes the linux aarch64 issues (observed when running Test java/foreign/TestUpcallStress.java ) .
> 
> Unfortunately we still see an assert in the test   java/foreign/TestUpcallStress on Linux aarch64 .
> But this time it is not the 'old' one but
> 
> `#  assert(oopDesc::is_oop(obj)) failed: not an oop: 0x0000000000000001`
> 
> Maybe it is unrelated, not sure .

> @MBaesken this looks rather unrelated, but hard to tell without more output.

Should I open a new JBS issue for it? Probably it is something else and we cannot address it in this PR .

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PR Comment: https://git.openjdk.org/jdk/pull/27408#issuecomment-3345400241