IV26343: JIT INLINE GUARD ELIMINATION CAUSING FAILURES

APAR status

• Closed as program error.

Error description

• Error Message: An exception occurs while executing a
  JIT-compiled Java method that gets an incorrect object address
  due to executing the inlined code of the wrong method.  The
  actual failure symptoms may vary depending on what incorrect
  inlined method gets executed.
  .
  Stack Trace: N/A
  .
  

Local fix

Problem summary

• The problem is caused by a internal JIT optimization that
  incorrectly eliminates inline guards in a particular scenario in
  which class hierarchy optimizations is disabled, but the inline
  guard should not be eliminated when class hierarchy
  optimizations is disabled.
  In very rare cases where the JIT compiler fails compilation of
  the method multiple times due to class hierarchy table changing,
  this problem can occur. It could also occur if a user explicitly
  uses the -Xjit:disableCHOpts option.
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR11
  6.0.1 SR2 FP1
  7.0.0 SR2
  .
  The JIT compiler has been updated to ensure that the inline
  guard does not get eliminated when class hierarchy optimizations
  is disabled.
  

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

• R600 PSY

     UP

• R260 PSY

     UP