LI77181: INCORRECT RESULT WITH -QHOT

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • test program produces incorrect result at runtime if compiled
    with -qhot.
    
    Adding "@PROCESS nohot" for the offending routines corrects the
    problem.
    

Local fix

  • use -qnohot
    

Problem summary

  • PROBLEM DESCRIPTION: incorrect result with -qhot
    
    USERS AFFECTED: the problem will happen when SIMD is enabled.
    It will affect three level or more nested loops, where the
    inner most loop has small iterations which can be fully
    unrolled. The statements in the inner most loops should contain
    three-dimensions arrays(should be stride on access, no control
    flow, no calls. also the array index should be simple
    expressions where compiler generated index code match specific
    internal pattern). The scenario is rare.
    

Problem conclusion

  • SIMD is trying to change 3-dim array index pattern which is
    wrong. Keep the index order as original order of the 3D array.
    Apply applicable service.
    

Temporary fix

Comments

APAR Information

  • APAR number

    LI77181

  • Reported component name

    XL FORTRAN FOR

  • Reported component ID

    5799AH100

  • Reported release

    E10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-12-21

  • Closed date

    2013-05-29

  • Last modified date

    2013-05-30

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

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

    LI77416

Fix information

  • Fixed component name

    XL FORTRAN FOR

  • Fixed component ID

    5799AH100

Applicable component levels

  • RE10 PSY

       UP



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Document information


More support for:

XL Fortran for Blue Gene/Q

Software version:

ALL VERSIONS

Reference #:

LI77181

Modified date:

2013-05-30

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