IV75205: CHARACTER ENCODING PERFORMANCE REGRESSION FOR BIG5, SHIFT-JIS, E UC_KR

APAR status

• Closed as program error.

Error description

• Error Message: Encoding Strings into BIG5, SHIFT-JIS, or EUC_KR
  is unexpectedly slow.
  .
  Stack Trace: N/A
  .
  

Local fix

Problem summary

• A jit optimization called Loop Versioner is capable of producing
  a fast version of a loop that runs only if certain conditions
  are met.  The optimizer elects to perform this transformation
  only in cases where those conditions are nearly always met, so
  we nearly never run the slow version of the loop.
  In this case, the jit erroneously concluded that a particular
  condition would nearly always be met, leading Loop Versioner to
  test that condition before entering the fast loop.  At run time,
  the condition usually failed, causing the slow version of the
  loop to run.
  

Problem conclusion

• The jit compiler has been modified to avoid optimizing
  rarely-executed bound checks from loops in this way, so that the
  fast copy of a loop does not require that those bound checks
  should succeed on every loop iteration. In particular, when a
  rarely executed bound check would fail but won't execute, the
  generated code will still run the fast loop.
  
  .
  This APAR will be fixed in the following Java Releases:
     8    SR1 FP10  (8.0.1.10)
  .
  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