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IV20275: INDUCTION VARIABLE CAUSING FAILURE IN COMPILED CODE

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APAR status

  • Closed as program error.

Error description

  • Error Message: The JVM fails or gives wrong result while
    executing a JIT-compiled Java method due to a loop being
    iterated the wrong number of times.
    .
    Stack Trace: N/A
    .
    

Local fix

  • The problem can be avoided by using the
    -Xjit:disableLoopUnroller option
    

Problem summary

  • This problem is caused by an incorrect loop unrolling
    optimization.  When calculating the number of loops, the
    optimization can pick up an incorrect value for certain unsigned
    values, resulting in the loop being unrolled an incorrect number
    of times.
    

Problem conclusion

  • This defect will be fixed in:
    6.0.1 SR2
    7.0.0 SR1
    .
    The JVM is updated to properly detect the right number of loops
    for the scenario identified so that the optimization will unroll
    the loops correctly.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV20275

  • Reported component name

    JIT

  • Reported component ID

    620700124

  • Reported release

    260

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-04-26

  • Closed date

    2012-04-26

  • Last modified date

    2012-06-01

  • 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

  • R260 PSY

       UP

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Document Information

Modified date:
01 June 2012