IJ23079: UNEXPECTED NPE CAUSED BY AN INCORRECT JIT COMPILER OPTIMIZATION

APAR status

• Closed as program error.

Error description

• Error Message: unexpected NPE thrown from the Java code
  .
  Stack Trace: java.lang.NullPointerException
   at sun.reflect.GeneratedMethodAccessor352.invoke(Unknown
  Source)
   at
  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethod
  AccessorImpl.java:55)
   at java.lang.reflect.Method.invoke(Method.java:508)
   ......
  .
  This problem applies to all the platforms.
  

Local fix

• Use Java option -Xjit:disablePRE. Notice this option disables an
  optimization and might have a performance impact.
  

Problem summary

• The problem is caused by a JIT compiler optimization named
  partial redundancy elimination. This optimization incorrectly
  removes the assignment of a certain variable from some code
  path.
  

Problem conclusion

• The optimization has been fixed to generate the correct code.
  Further details can be found in
  https://github.ibm.com/runtimes/openj9-omr/pull/65
  .
  This APAR will be fixed in the following Java Releases:
   8 SR6 FP7 (8.0.6.7)
  .
  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:

Fix information

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels