IJ15737: CRASH IN JIT COMPILER AFTER AUTOSIMD

APAR status

• Closed as program error.

Error description

• Error Message: A SIGSEGV/GPF is raised by the JIT compiler. The
  problem is known to be hit when compiling
  java/awt/image/BufferedImage.<init>(III)V
  .
  Stack Trace: Multiple stack traces are possible. One known stack
  trace is:
  TR_UseDefInfo::findTrivialSymbolsToExclude
  TR_UseDefInfo::AuxiliaryData
  TR_UseDefInfo::prepareUseDefInfo
  TR_UseDefInfo::TR_UseDefInfo
  OMR::Optimizer::performOptimization
  .
  The problem can only be hit on a SIMD capable machine with
  vector instructions.
  

Local fix

• The problem can be avoided using the following command line
  option:
  -Xjit:disableAutoSIMD
  Note, use of this option may have a performance impact. It is
  likely to be negligible, but certain workloads that
  significantly benefit from vectorization may notice an impact.
  

Problem summary

• The JIT compiler may try and convert loops in order to make use
  of SIMD vector instructions to accelerate performance. If a loop
  is suitable for this optimization, and has a statement like
  a<OSB>i<CSB> = i; where i is a loop counter, then the
  optimization may not properly set internal JIT data structures
  in the compiler's IL. A subsequent optimization will then crash
  when encountering the problematic data structure(s).
  

Problem conclusion

• This problem has been addressed by
  https://github.com/eclipse/openj9/pull/5200
  .
  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:

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels