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LI76044: INCORRECT CALCULATION RESULTS WITH -QHOT

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When compiling with -qhot or -O3 (which implies -qhot=level=0),
    incorrect values are seen when the compiler performs function
    splitting optimizations.  The function splitting optimizing
    behaviour may be related to the usage of -qarch settings that
    include support for square root instructions.
    
    Values in the function stored as Fortran variables with the SAVE
    attribute, or C/C++ variables with function-scope static
    specifiers may not be stored correctly, resulting in unexpected
    results.
    
    Note:  on Linux, the default -qarch setting, -qarch=ppc64grsq,
    includes support for sqrt instructions.
    

Local fix

  • Users may be able to disable the function splitting behaviour in
    some cases by using a -qarch setting that does not include
    support for square root instructions.
    

Problem summary

  • PROBLEM DESCRIPTION:
    Incorrect optimization of procedure with function scope static.
    
    USERS AFFECTED:
    Users that compile with optimization and have function scope
    static may encounter this problem.
    

Problem conclusion

  • The issue was corrected.
    

Temporary fix

Comments

APAR Information

  • APAR number

    LI76044

  • Reported component name

    XL FORTRAN LINU

  • Reported component ID

    5724X1600

  • Reported release

    D10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2011-03-18

  • Closed date

    2011-07-13

  • Last modified date

    2011-07-13

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

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

    IZ99242

Fix information

  • Fixed component name

    XL FORTRAN LINU

  • Fixed component ID

    5724X1600

Applicable component levels

  • RD10 PSY

       UP

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Document Information

Modified date:
16 October 2021