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IV63802: JIT-COMPILED METHOD WITH DIVISION OR MODULO RETURNS INCORRECT RE SULT

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Error Message: A Java method with a large number of division or
    modulo operations may return incorrect results after being
    JIT-compiled. This issue was first discovered in IBM DB2 Content
    Manager's Resource Manager application (the
    com/ibm/mm/icmrm/util/RMTokenValidator.encrypt method) but may
    be encountered in other programs too.This issue only affects
    System z platforms (z/OS and Linux).
    .
    Stack Trace: N/A
    .
    

Local fix

  • This issue can be avoided by excluding the offending method from
    compilation with a JVM option,
    e.g.-Xjit:exclude={com/ibm/mm/icmrm/util/RMTokenValidator.encryp
    t*}
    

Problem summary

  • The problem is caused by an incorrect placement of a register
    spill within the division instruction sequence by the JIT
    compiler.
    

Problem conclusion

  • The JIT compiler has been updated to produce correct code in
    this scenario.
    .
    This APAR will be fixed in the following Java Releases:
       6    SR16 FP2  (6.0.16.2)
       7 R1 SR2       (7.1.2.0)
       5.0  SR16 FP9  (5.0.16.9)
       6 R1 SR8 FP2   (6.1.8.2)
       7    SR8       (7.0.8.0)
    .
    Contact your IBM Product's Service Team for these Service
    Refreshes and Fix Packs.
    For those running stand-alone, Java maintenance is available
    from:
               https://www.ibm.com/developerworks/java/jdk/
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV63802

  • Reported component name

    JIT

  • Reported component ID

    620700124

  • Reported release

    600

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-08-20

  • Closed date

    2014-10-04

  • Last modified date

    2014-10-04

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    IV63803

Fix information

  • Fixed component name

    JIT

  • Fixed component ID

    620700124

Applicable component levels

  • R600 PSY

       UP

  • R130 PSY

       UP

  • R260 PSY

       UP



Document information

More support for: Runtimes for Java Technology
Just In Time (JIT) Compiler

Software version: 6.0

Reference #: IV63802

Modified date: 04 October 2014