On Tue, 7 Jul 2026 07:54:12 GMT, Kuai Wei <[email protected]> wrote: > I recently noticed a behavioral discrepancy in > jdk.internal.util.ArraysSupport.vectorizedMismatch between the Java > implementation and the platform intrinsic implementations. > > Current behavior > > The Java implementation may leave a tail of elements unchecked, returning the > bitwise complement of the number of remaining elements (i.e., ~remaining). > The x86_64 intrinsic, by contrast, compares all elements and simply returns > -1 when no mismatch is found. > > Proposed change > > This PR refines the Java implementation so that it always compares all > elements and returns -1 when no mismatch is found, matching the x86_64 > intrinsic behavior. > > A regression test is included at > `test/hotspot/jtreg/compiler/intrinsics/VectorizedMismatchReturnDiffTest.java` > which demonstrates the original behavioral difference. > > ## Test > - [x] tier1 test suites on linux x86_64 > - [x] tier1 test suites on linux aarch64 > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai).
This pull request has now been integrated. Changeset: 80133d4d Author: Kuai Wei <[email protected]> Committer: Denghui Dong <[email protected]> URL: https://git.openjdk.org/jdk/commit/80133d4dc7519f88315b4cb67fb8f32a7de8f516 Stats: 388 lines in 6 files changed: 273 ins; 73 del; 42 mod 8387812: Refine ArraysSupport.vectorizedMismatch to compare all elements Reviewed-by: vlivanov, liach ------------- PR: https://git.openjdk.org/jdk/pull/31802
