On Tue, 23 Dec 2025 07:27:36 GMT, Eric Fang <[email protected]> wrote:
>> 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. > > Eric Fang has updated the pull request incrementally with one additional > commit since the last revision: > > wrap the test loop within a try/catch to speed up the tests Marked as reviewed by qamai (Committer). ------------- PR Review: https://git.openjdk.org/jdk/pull/28692#pullrequestreview-3606938781
