On Tue, 16 Dec 2025 03:31:07 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 with a new target base due to a merge > or a rebase. The pull request now contains four commits: > > - Merge branch 'master' into JDK-8372978-fix-umin-umax-identity > - Declare two constants for UMIN/UMAX reduction identity values > - Merge branch 'master' into JDK-8372978-fix-umin-umax-identity > - 8372978: [VectorAPI] Fix incorrect identity values in UMIN/UMAX reductions > > 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. Hi, could you please take another look at this PR? I've already processed all your comments. @merykitty @PaulSandoz And @XiaohongGong @shqking ------------- PR Comment: https://git.openjdk.org/jdk/pull/28692#issuecomment-3658575085
