IV77943: JIT COMPILED CODE DOES NOT CORRECTLY EVALUATE INSTANCEOF TEST FO R 2-D OR HIGHER ARRAY CLASSES

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: N/A
  .
  This problem is known to potentially occur when using Spark, but
  it is not specific to Spark.
  

Local fix

Problem summary

• The problem is caused when the JIT compiler checks if Class C is
  '<OSB>Ljava/lang/Object;'. If C is '<OSB>Ljava/lang/Object;',
  the JIT compiler will generate a fast sequence for the
  instanceof(C) test. It checks the leaf component but it should
  check the entry type. As a result, when C is a 2-D array, e.g.
  '<OSB><OSB>Ljava/lang/Object;', a fast sequence will be
  generated but it should not be, which can cause unexpected
  behaviour.
  

Problem conclusion

• The JIT compiler has been updated to properly check the entry
  type instead of leaf component in this case.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR2       (8.0.2.0)
  .
  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

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