> 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).
Kuai Wei has updated the pull request incrementally with one additional commit since the last revision: Check remaining bytes wo temp buffer ------------- Changes: - all: https://git.openjdk.org/jdk/pull/31802/files - new: https://git.openjdk.org/jdk/pull/31802/files/b3e46578..47ce2cd3 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=31802&range=03 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=31802&range=02-03 Stats: 35 lines in 1 file changed: 15 ins; 11 del; 9 mod Patch: https://git.openjdk.org/jdk/pull/31802.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/31802/head:pull/31802 PR: https://git.openjdk.org/jdk/pull/31802
