On Fri, 3 Oct 2025 14:12:34 GMT, Tobias Hartmann <[email protected]> wrote:
> The new memory model rules for strict instance fields (see > [JDK-8366372](https://bugs.openjdk.org/browse/JDK-8366372)) require a memory > barrier at the beginning of `java.lang.Object::<init>`. The JITs will try to > omit it if the receiver type is statically known (potentially via CHA + a > dependency) and the class does not contain any strict fields. > > Potentially, there's some more tricks that we can play. Most importantly, I > think we can omit barriers for final fields at the end of the constructors if > the field is also strict. I filed > [JDK-8369166](https://bugs.openjdk.org/browse/JDK-8369166) for this. > > I added a test that already caught > [JDK-8369044](https://bugs.openjdk.org/browse/JDK-8369044) and will fail > immediately without the JIT changes (on AArch64). > > Thanks, > Tobias Looks good to me and nice test! test/hotspot/jtreg/compiler/valhalla/inlinetypes/TestStrictFieldBarriers.java line 204: > 202: if (res != 1) { > 203: System.err.println("Incorrect field value > observed!"); > 204: System.exit(1); Is there any particular reason why you don't throw a `RuntimeException` here instead? ------------- Marked as reviewed by chagedorn (Committer). PR Review: https://git.openjdk.org/valhalla/pull/1656#pullrequestreview-3303271947 PR Review Comment: https://git.openjdk.org/valhalla/pull/1656#discussion_r2405254858
