IJ18031: INCORRECT RESULTS FROM JAVA.TEXT.DECIMALFORMAT

APAR status

• Closed as program error.

Error description

• Error Message: After a period of correct operation, incorrect
  results were obtained from DecimalFormat.format where the
  parameter is a BigDecimal.doubleValue() expression. Errors in
  the output may include an incorrect number of trailing zeros
  after the decimal point, and incorrect rounding of the least
  significant digit.
  .
  Stack Trace: N/A
  .
  

Local fix

• The problem is caused by the decimal format peephole
  optimisation and can be avoided by disabling that optimisation
  with
  -Xjit:disableDecimalFormatPeephole
  

Problem summary

• The conversion of a BigDecimal to a double or float value and
  it's subsequent use by DecimalFormat.format involves a large
  amount of redundant work. The decimal format peephole attempted
  to avoid some of this work by combining elements of both methods
   into a single implementation. Unfortunately, maintaining
  identical behaviour for all of the possible formatting options
  was not achieved.
  

Problem conclusion

• The faulty optimisation will be removed in a future release of
  the JVM. For now it has been disabled by default. If an
  application experiences a performance impact because of this
  change, and can tolerate the differences in behaviour described
  above, then the optimisation can be re-enabled by using the
  inverted option
  
  -Xjit:!disableDecimalFormatPeephole
  
  (NB there can only be a single active Xjit option on the JVM
  command line, so if multiple flags are required they can be
  combined with commas.)
  .
  This APAR will be fixed in the following Java Releases:
   7R1 SR4 FP50 (7.1.4.50)
   8 SR5 FP41 (8.0.5.41)
  
  .
  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