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IJ10561: DUPLICATED ELSE BLOCK WHEN USING -QHOT

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APAR status

  • Closed as program error.

Error description

  • When compiling with the -qhot optimization level, an incorrect
    optimization is performed that causes both the true and false
    blocks of an IF statement to execute identical code.  For
    example:
    
    if(test==0)
       do_one();
    else
       do_two();
    
    In this case, the false/else block is run in both IF scenarios,
    i.e. test==0 or test!=0.
    

Local fix

  • Compile with -qhot=level=0 or -qnohot
    

Problem summary

  • PROBLEM DESCRIPTION:
    The issue was determined to be an incorrect loop transformation
    optimization applied when using -qhot.
    
    USERS AFFECTED:
    The rare optimization issue may be seen in code that uses -qhot
    and contains a loop structure that has the ability to break out
    of the loop.
    

Problem conclusion

  • The optimization was corrected, and correct code is now
    generated.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IJ10561

  • Reported component name

    XL C/C++ FOR AI

  • Reported component ID

    5725C7200

  • Reported release

    D10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2018-10-18

  • Closed date

    2018-12-21

  • Last modified date

    2018-12-21

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

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

    IJ15521 IJ16324

Fix information

  • Fixed component name

    XL C FOR AIX

  • Fixed component ID

    5725C7100

Applicable component levels



Document information

More support for: XL C for AIX
Compiler

Software version: 13.1

Reference #: IJ10561

Modified date: 21 December 2018