IV11693: JIT COMPILATION CRASH ON SYSTEM Z

APAR status

• Closed as program error.

Error description

• Error Message: A SIGSEGV or S0C4 ABEND is raised during the
  compilation of a method containing loops that process byte
  arrays. This problem is only seen with Java 6 (or above) running
  on z/OS or z/Linux.
  .
  Stack Trace: TR_CFG::addSuccessorEdges
  TR_CISCTransformer::insertBeforeNodes
  CISCTransform2BitOpMem
  TR_CISCTransformer::computeTopologicalEmbedding
  TR_CISCTransformer::perform
  TR_OptimizerImpl::performOptimization
  TR_OptimizerImpl::optimize
  TR_Compilation::compile
  .
  

Local fix

• This issue can be worked around using the
  -Xjit:disableIdiomRecognition option. This may cause a
  negligible to moderate impact on the performance of the Java
  application.
  

Problem summary

• The problem is caused by an incorrect code transformation by an
  optimization in the JIT compiler. The method being compiled
  contains a for loop or while loop that iterates over two byte
  arrays, computes the exclusive-or of successive elements, and
  stores the results into a third byte array. This particular code
  pattern triggers a program bug which leads to the crash.
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR10
  6.0.1 SR1
  7.0.0 SR1
  .
  The JIT compiler has been updated to correct the algorithm used
  for this optimization.
  

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

• R600 PSY

     UP

• R260 PSY

     UP