IV78172: PROBLEM WITH JIT COMPILED CODE WITH AUTO-SIMD

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: N/A
  .
  This problem can only occur if auto-SIMD is enabled on either
  the z13 platform or POWER 7 or later platform.
  

Local fix

• -Xjit:disableAutoSIMD
  Note that this may affect performance.
  

Problem summary

• While trying to vectorize a loop of the form do {...} while (i++
  < N) the JIT compiler incorrectly generated code that checks the
  post-incremented value of i instead of the pre-incremented
  value. This can cause the loop to execute one extra iteration.
  

Problem conclusion

• The JIT compiler has been updated to skip vectorization of loops
  that check the pre-increment value of the induction variable.
  .
  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

     UP