IV98234: JAVA JIT: COMPILER TIME CRASH IN ANALYZEEXITEDGES()

APAR status

• Closed as program error.

Error description

• Error Message: A SIGSEGV/GPF while JIT compiling a method.
  .
  Stack Trace:
  {libj9jit28.so}{analyzeExitEdges__28TR_InductionVariableAnalysis
  FP18TR_RegionStructureP12TR_BitVectorR8TR_ArrayXTP25TR_BasicIndu
  ctionVariable_}
  {libj9jit28.so}{analyzeLoopExpressions__28TR_InductionVariableAn
  alysisFP18TR_RegionStructurePPQ2_28TR_InductionVariableAnalysis9
  DeltaInfo}
  {libj9jit28.so}{analyzeNaturalLoop__28TR_InductionVariableAnalys
  isFP18TR_RegionStructure}
  {libj9jit28.so}{perform__28TR_InductionVariableAnalysisFP18TR_Re
  gionStructure}
  {libj9jit28.so}{perform__28TR_InductionVariableAnalysisFP18TR_Re
  gionStructure}
  {libj9jit28.so}{perform__28TR_InductionVariableAnalysisFP18TR_Re
  gionStructure}
  {libj9jit28.so}{perform__28TR_InductionVariableAnalysisFv}
  {libj9jit28.so}{performOptimization__16TR_OptimizerImplFPC12Opti
  mizationiN22}
  {libj9jit28.so}{performOptimization__16TR_OptimizerImplFPC12Opti
  mizationiN22}
  {libj9jit28.so}{optimize__16TR_OptimizerImplFv}
  {libj9jit28.so}{performOptimizations__14TR_CompilationFv}
  {libj9jit28.so}{compile__14TR_CompilationFv}
  .
  

Local fix

• The problem can be avoid by preventing the JIT from compiling
  the method that was being compiled when the crash occurred by
  using the following Java command line option:
  -Xjit:exclude={package/Class.method*}
  

Problem summary

• The JIT would attempt to analyze induction variables within a
  loop but the JIT finds that an inner loop modifies the induction
  variable causing an inconsistency that results in a crash.
  

Problem conclusion

• The JIT was modified so that loop induction variable analysis it
  will only consider loops where induction variables are only
  modified within the basic loop body.
  .
  This APAR will be fixed in the following Java Releases:
   8 SR4 FP10 (8.0.4.10)
   7 SR10 FP10 (7.0.10.10)
   6 R1 SR8 FP50 (6.1.8.50)
   6 SR16 FP50 (6.0.16.50)
  .
  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

     UP

• R260 PSY

     UP

• R600 PSY

     UP