The original implementation of UMIN/UMAX reductions in JDK-8346174 used incorrect identity values in the Java implementation and test code.
Problem: -------- UMIN was using MAX_OR_INF (signed maximum value) as the identity: - Byte.MAX_VALUE (127) instead of max unsigned byte (255) - Short.MAX_VALUE (32767) instead of max unsigned short (65535) - Integer.MAX_VALUE instead of max unsigned int (-1) - Long.MAX_VALUE instead of max unsigned long (-1) UMAX was using MIN_OR_INF (signed minimum value) as the identity: - Byte.MIN_VALUE (-128) instead of 0 - Short.MIN_VALUE (-32768) instead of 0 - Integer.MIN_VALUE instead of 0 - Long.MIN_VALUE instead of 0 This caused incorrect result. For example: UMAX([42,42,...,42]) returned 128 instead of 42 Solution: --------- Use correct unsigned identity values: - UMIN: ($type$)-1 (maximum unsigned value) - UMAX: ($type$)0 (minimum unsigned value) Changes: -------- - X-Vector.java.template: Fixed identity values in reductionOperations - gen-template.sh: Fixed identity values for test code generation - templates/Unit-header.template: Updated copyright year to 2025 - Regenerated all Vector classes and test files Testing: -------- All types (byte/short/int/long) now return correct results in both interpreter mode (-Xint) and compiled mode. ------------- Commit messages: - 8372978: [VectorAPI] Fix incorrect identity values in UMIN/UMAX reductions Changes: https://git.openjdk.org/jdk/pull/28692/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28692&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8372978 Stats: 364 lines in 37 files changed: 0 ins; 0 del; 364 mod Patch: https://git.openjdk.org/jdk/pull/28692.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/28692/head:pull/28692 PR: https://git.openjdk.org/jdk/pull/28692
