> This PR updates the Test `compiler/stable/TestStableArrayMembars.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).
Manuel Hässig has updated the pull request incrementally with one additional commit since the last revision: Update test/hotspot/jtreg/compiler/stable/TestStableArrayMembars.java Co-authored-by: Tobias Hartmann <[email protected]> ------------- Changes: - all: https://git.openjdk.org/valhalla/pull/2441/files - new: https://git.openjdk.org/valhalla/pull/2441/files/9bbe2279..af60ed60 Webrevs: - full: https://webrevs.openjdk.org/?repo=valhalla&pr=2441&range=01 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=2441&range=00-01 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.org/valhalla/pull/2441.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2441/head:pull/2441 PR: https://git.openjdk.org/valhalla/pull/2441
