IJ14196: JAVA JIT PPC: COMPILE TIME CRASH IN USEREGISTER()

APAR status

• Closed as program error.

Error description

• Error Message: A SIGSEGV at JIT compile time.
  .
  Stack Trace: OMR::Instruction::useRegister()
  OMR::Power::RegisterDependencyConditions::bookKeepingRegisterUse
  s()
  generateDepConditionalBranchInstruction()
  OMR::Power::TreeEvaluator::compareLongsForEquality()
  OMR::Power::TreeEvaluator::ifacmpneEvaluator()
  ...
  Note: The stack trace may look significantly different to this.
  This is only an example of one instance of this issue.
  .
  This problem can only occur on POWER (PPC) processors and only
  in Java 8 SR5 through Java 8 SR5 FP30.
  The problem will most likely result in a JIT compile time crash
  but it's also possible that the problem will result in
  unexpected exceptions or unexpected behaviour.
  This APAR caused a performance regression that is described by
  APAR IJ21489
  

Local fix

• The problem can be avoid by setting the following environment
  variable prior to starting the JVM:
  export TR_DisableDirectNativeCall=1
  This will have a minimal effect on performance.
  

Problem summary

• The JIT might fail to generate code to call a JNI method when
  the same JNI method is called more then once within the same
  method. The issue occurs when the JIT is able to devirtualize
  one of the calls but another call can not be devirtualized.
  

Problem conclusion

• The JIT was modified such that shared method symbols used in a
  direct call sequence are not marked in a way that makes them
  unsuitable for indirect calls sequences.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5 FP35  (8.0.5.35)
  .
  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