IV73740: WRONG RESULT FROM JAVA/LANG/INTEGER.NUMBEROFLEADINGZEROS ON JAVA 8 X86 64-BIT JVM

APAR status

• Closed as program error.

Error description

• Error Message: Any test failures caused by wrong return value
  from java/lang/Integer.numberOfLeadingZeros. This method is also
  called in a lot of JCL code.
  .
  Stack Trace: N/A
  .
  

Local fix

• -Xjit:disableBitOpcode
  

Problem summary

• In the implementation of java/lang/Integer.numberOfLeadingZeros,
  JIT compiler uses 64-bit registers for a 32-bit operation,
  resulting in a wrong return value. This problem is only seen on
  Java8 x86 64-bit JVM
  

Problem conclusion

• The JIT compiler has been changed to use the correct register.
  .
  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:

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R130 PSY

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