JDK-8255437 : [vector] jdk/incubator/vector/SelectFromByteMaxVectorTests fails with Arm SVE 2048-bits
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: repo-panama
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • OS: linux
  • CPU: aarch64
  • Submitted: 2020-10-27
  • Updated: 2020-11-02
  • Resolved: 2020-11-02
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
Other
repo-panamaFixed
Related Reports
Relates :  
JDK-8223347 - Integration of Vector API (Incubator)
Description
"jdk/incubator/vector/SelectFromByteMaxVectorTests" and "jdk/incubator/vector/SelectFromByteMaxVectorTestsMaskedSmokeTest" fail with IndexOutOfBoundsException on Arm SVE 2048-bits:

test ByteMaxVectorTests.SelectFromByteMaxVectorTests(byte[-i * 5], shuffle[random]): failure
java.lang.IndexOutOfBoundsException: required an index in [0..255] but found -66
    at jdk.incubator.vector/jdk.incubator.vector.AbstractShuffle.checkIndexFailed(AbstractShuffle.java:288)
    at jdk.incubator.vector/jdk.incubator.vector.AbstractShuffle.checkIndexes(AbstractShuffle.java:187)
    at jdk.incubator.vector/jdk.incubator.vector.ByteVector.rearrangeTemplate(ByteVector.java:2091)
    at jdk.incubator.vector/jdk.incubator.vector.ByteMaxVector.rearrange(ByteMaxVector.java:469)
    at jdk.incubator.vector/jdk.incubator.vector.ByteMaxVector.rearrange(ByteMaxVector.java:43)
    at jdk.incubator.vector/jdk.incubator.vector.ByteVector.selectFromTemplate(ByteVector.java:2210)
    at jdk.incubator.vector/jdk.incubator.vector.ByteMaxVector.selectFrom(ByteMaxVector.java:497)
    at jdk.incubator.vector/jdk.incubator.vector.ByteMaxVector.selectFrom(ByteMaxVector.java:43)
    at ByteMaxVectorTests.SelectFromByteMaxVectorTests(ByteMaxVectorTests.java:5039)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:639)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:821)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1131)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
    at org.testng.TestRunner.privateRun(TestRunner.java:773)
    at org.testng.TestRunner.run(TestRunner.java:623)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:357)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:352)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:310)
    at org.testng.SuiteRunner.run(SuiteRunner.java:259)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1185)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1110)
    at org.testng.TestNG.run(TestNG.java:1018)
    at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:94)
    at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:54)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
    at java.base/java.lang.Thread.run(Thread.java:832)

The main reason is: for 2048-bits, the max vector length for byte is "2048 / 8 = 256" which is out of the byte range "-128 ~ 127".  The above cases do the shuffles with a random index in the range [0, 256), and the index value will be saved to a byte array. For indexes that above "127", their actual values are negative.  So the valid lane elements for API "selectFrom" should be 0 ~ 127 for bytes, it's better to limit the indexes in the tests.