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 This pull request has now been integrated. Changeset: f8ced6c2 Author: Tobias Hartmann <[email protected]> URL: https://git.openjdk.org/valhalla/commit/f8ced6c209019c12dea9949dbd4074e06735ef21 Stats: 291 lines in 4 files changed: 291 ins; 0 del; 0 mod 8367785: [lworld] Compiler adherence to new memory model rules for strict instance fields Reviewed-by: chagedorn ------------- PR: https://git.openjdk.org/valhalla/pull/1656
