On Fri, 15 May 2026 13:04:02 GMT, Manuel Hässig <[email protected]> wrote:
> This PR updates the Test `compiler/stable/TestStabelArrayMembars.java` for > Valhalla. This involves creating a code path for migrated value classes and a > slight change to C2 to be able to clean up more barriers than previously. > > Unfortunately, with `--enable-preview` C2 is not able to fully clean up all > membars as it is for mainline. This is due to the later elision of the loads. > After parsing, membars do not carry information that could relate them to any > particular memory access, so we cannot remove them without potentially > violating the JMM. Further, the implementation of > `Unsafe.getFlatValueAcquire` emits a barrier in Java that cannot be > eliminated by the JIT anyways. > > Testing: > - [x] tier1,tier2 and additional stress testing. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). I understand what this does, and I'm convinced by the explanation in the PR description. I'm not very knowledgeable about memory graph, and I don't realize whether this could have some unforeseen side effects. ------------- PR Comment: https://git.openjdk.org/valhalla/pull/2441#issuecomment-4485709588
