IV98235: FLOATING POINT ERROR IN JIT COMPILER

APAR status

• Closed as program error.

Error description

• Error Message: A floating point error is raised by the JIT
  compiler during method compilation causing the Java Runtime
  Environment to unexpectedly terminate.
  .
  Stack Trace:
  TR_ResolvedJ9MethodBase::isCold(TR_Compilation*,bool,TR_Resolved
  MethodSymbol*)
  TR_J9EstimateCodeSize::realEstimateCodeSize(TR_CallTarget*,TR_Ca
  llStack*,bool)
  TR_J9EstimateCodeSize::estimateCodeSize(TR_CallTarget*,TR_CallSt
  ack*,bool)
  TR_EstimateCodeSize::calculateCodeSize(TR_CallTarget*,TR_CallSta
  ck*,bool)
  TR_InlinerBase::applyPolicyToTargets(TR_CallStack*,TR_CallSite*)
  TR_InlinerBase::getSymbolAndFindInlineTargets(TR_CallStack*,TR_C
  allSite*,bool)
  TR_MultipleCallTargetInliner::walkCallSites(TR_ResolvedMethodSym
  bol*,TR_CallStack*,TR_Inner...
  TR_MultipleCallTargetInliner::doWalkCallSites(TR_ResolvedMethodS
  ymbol*,TR_InnerPreexistence...
  TR_InlinerBase::performInlining(TR_ResolvedMethodSymbol*)
  TR_Inliner::perform()
  TR_OptimizerImpl::performOptimization(const
  Optimization*,int,int,int)
  TR_OptimizerImpl::optimize()
  TR_Compilation::performOptimizations()
  TR_Compilation::compile()
  .
  

Local fix

• This problem can be avoided by disabling inlining. However,
  doing that globally is likely to affect performance, so it
  should only be disabled on the method which the JIT compiler is
  crashing trying to compile to minimize performance impact using
  the following Java command line option template:
  -Xjit:{package/Class.method(signature)}(disableInlining)
  

Problem summary

• The JIT compiler makes calculations which include division as
  part of its heuristics. In rare cases a value can be zero and a
  calculation which uses this value as the divisor did not guard
  against the possibility of the value being zero leading to the
  possibility of a division by zero error which causes the JRE to
  crash reporting a Floating Point Error.
  

Problem conclusion

• The JIT compiler has been updated to guard against the value
  being zero to prevent a division by zero error.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR4 FP10  (8.0.4.10)
     7 R1 SR4 FP10  (7.1.4.10)
     6 R1 SR8 FP50  (6.1.8.50)
     6    SR16 FP50 (6.0.16.50)
     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

• R260 PSY

     UP

• R600 PSY

     UP