IV85347: JIT COMPILER CRASHES OR HANGS DURING IDIOM TRANSFORMATION

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: TR_TreeTop::getEnclosingBlock(bool)
  CISCTransform2CopyingTROx(TR_CISCTransformer*)
  ...
  .
  The JVM receives a segmentation fault. On AIX the JIT compiler
  hangs with high
  CPU usage instead.
  In Java 7, 6.1, and 6, this problem only occurs on
  z/Architecture.
  

Local fix

• The issue can be avoided with -Xjit:disableIdiomRecognition.
  This option has
  some performance impact, but it may be restricted to the
  problematic method.
  

Problem summary

• An optimization in the JIT compiler recognized a loop and
  attempted to
  transform it into a specialized sequence of instructions. The
  particular loop
  had a highly specific unanticipated sequence of intermediate
  code that caused
  the transformation to fail.
  

Problem conclusion

• The compiler has been modified so that it will identify loops
  that are
  problematic in this way and avoid transforming them.
  .
  This APAR will be fixed in the following Java Releases:
   8 SR3 FP10 (8.0.3.10)
   6 SR16 FP30 (6.0.16.30)
   6 R1 SR8 FP30 (6.1.8.30)
   7 R1 SR3 FP50 (7.1.3.50)
   7 SR9 FP50 (7.0.9.50)
  .
  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

• R600 PSY

     UP

• R260 PSY

     UP