IBM Support

IV68043: INCORRECT VALUE PRODUCED FROM FLOATING POINT COMPUTATION

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APAR status

  • Closed as program error.

Error description

  • Error Message: A Java program behaves incorrectly or produces
    incorrect output because a floating point value is incorrect
    during program execution. The incorrect value will be a
    different valid floating point value that is either an
    intermediate result of a floating point calculation or the value
    of floating point variable somewhere in the program.
    .
    Stack Trace: N/A
    .
    The Java method that generates the invalid value will contain at
    least one lookupswitch bytecode.
    

Local fix

  • The problem can be worked around using the -Xjit:exclude=
    command line option to exclude the method that generates the
    faulty floating point value from compilation, this is likely to
    cause some performance degradation.
    

Problem summary

  • The invalid value results from floating point value dependency
    information not being fully propagated across lookupswitch
    bytecodes during JIT compilation of the method.
    

Problem conclusion

  • The JIT compiler has been enhanced to ensure floating point
    value dependency information is propagated across lookupswitch
    bytecodes in all cases to ensure values are correctly computed.
    .
    This APAR will be fixed in the following Java Releases:
       7 R1 SR3       (7.1.3.0)
       7    SR9       (7.0.9.0)
       6 R1 SR8 FP4   (6.1.8.4)
       6    SR16 FP4  (6.0.16.4)
    .
    Contact your IBM Product's Service Team for these Service
    Refreshes and Fix Packs.
    For those running stand-alone, information about the Service
    Refreshes and Fix Packs can be found at:
               https://www.ibm.com/developerworks/java/jdk/
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV68043

  • Reported component name

    JIT

  • Reported component ID

    620700124

  • Reported release

    130

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-12-17

  • Closed date

    2014-12-17

  • Last modified date

    2014-12-17

  • 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

  • R260 PSY

       UP

  • R600 PSY

       UP

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Document Information

Modified date:
17 December 2014