IV97890: JIT COMPILER PROBLEM HANDLING EMPTY CONTROL FLOW BLOCK

APAR status

• Closed as program error.

Error description

• Error Message: The most common symptoms are segmentation error
  during JIT compilation, or in a JIT compiled method.
  .
  Stack Trace: N/A
  .
  This problem affects all platforms.
  

Local fix

Problem summary

• The problem can occur when we have a branch bytecode, such as
  ifnull and ifnonnull, which targets the fall through of the
  branch, i.e. the next bytecode. For example, Java code
  containing an if statement with an empty body will result in
  such bytecode:
  if (null == null){}
  The bytecodes are:
  29: ifnonnull     32
  32: return
  This is an unexpected pattern for the JIT compiler and it may
  either crash when compiling it or generate a JIT compiled method
  with errors which can result in a crash in JIT compiled code or
  other symptoms.
  

Problem conclusion

• The JIT compiler has been updated to detect and remove such
  branches, which are dead code.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR4 FP7   (8.0.4.7)
     6    SR16 FP50 (6.0.16.50)
     7 R1 SR4 FP10  (7.1.4.10)
     7    SR10 FP10 (7.0.10.10)
  .
  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:

Fix information

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R130 PSY

     UP

• R600 PSY

     UP

• R260 PSY

     UP