IV80395: JAVA THROWS ILLEGAL INSTRUCTION EXCEPTION ON IBM ISERIES

APAR status

• Closed as program error.

Error description

• Error Message: A Illegal Instruction exception is thrown when
  user run a java problem on a P7 iSeries machine.
  .
  Stack Trace:
  javasoft/sqe/tests/api/java/io/StreamTokenizer/STate.resetSyntax
  (STate.java)
  javasoft/sqe/tests/api/java/io/StreamTokenizer/STate.resetState(
  STate.java:104(Compiled Code))
  javasoft/sqe/tests/api/java/io/StreamTokenizer/STate.testState(S
  Tate.java:407)
  javasoft/sqe/tests/api/java/io/StreamTokenizer/commentCharTests.
  StreamTokenizer0050(commentCharTests.java:48)
  sun/reflect/NativeMethodAccessorImpl.invoke0(Native Method)
  sun/reflect/NativeMethodAccessorImpl.invoke(NativeMethodAccessor
  Impl.java:95)
  .
  

Local fix

• This issue can be worked around using the -Xjit:disableAutoSIMD
  option.
  

Problem summary

• The problem is caused when a iSeries machine trying to execute a
  SIMD load/store on a non dword-aligned address. This issue is
  only seen on iSeries with Power 7 cpu, because on Power 7
  system, such instructions requires extra support from OS. Those
  instructions are not safe for IBM iSeries.
  

Problem conclusion

• The JIT has been updated to prevent the crash from occurring by
  only generate safe SIMD load/store instructions on Power 7.
  .
  This APAR will be fixed in the following Java Releases:
   8 SR2 FP10 (8.0.2.10)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  Service Refreshes and Fix Packs can be found at:
   https://www.ibm.com/developerworks/java/jdk/
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R130 PSY

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