IBM Support

IZ79546: COMPILER ERROR AND WRONG OUTPUT WITH -QARCH

Fixes are available

September 2010 PTF for XL C for AIX, V11.1
September 2010 PTF for XL C/C++ for AIX, V11.1
January 2011 PTF for XL C/C++ for AIX, V11.1
May 2011 PTF for XL C for AIX, V11.1
May 2011 PTF for XL C/C++ for AIX, V11.1
August 2011 PTF for XL C/C++ for AIX, V11.1
November 2011 PTF for XL C/C++ for AIX, V11.1
January 2012 PTF for XL C for AIX, V11.1
January 2012 PTF for XL C/C++ for AIX, V11.1
April 2012 PTF for XL C for AIX, V11.1
April 2012 PTF for XL C/C++ for AIX, V11.1
July 2012 PTF for XL C/C++ for AIX, V11.1
October 2012 PTF for XL C for AIX, V11.1
October 2012 PTF for XL C/C++ for AIX, V11.1
February 2013 PTF for XL C for AIX, V11.1
February 2013 PTF for XL C/C++ for AIX, V11.1
XL C/C++ for AIX Fix Pack 14 (May 2013 PTF) for 11.1
XL C for AIX Fix Pack 14 (May 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 15 (August 2013 PTF) for 11.1
XL C for AIX Fix Pack 15 (August 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 16 (November 2013 PTF) for 11.1
XL C for AIX Fix Pack 17 (February 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 17 (February 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 18 (May 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 19 (August 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 20 (November 2014 PTF) for 11.1
XL C for AIX Fix Pack 21 (April 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 21 (April 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 22 (September 2015 PTF) for 11.1
XL C for AIX Fix Pack 23 (March 2016 PTF) for 11.1
XL C/C++ for AIX Fix Pack 23 (March 2016 PTF) for 11.1
XL C for AIX Fix Pack 24 (September 2016 PTF) for 11.1
XL C/C++ for AIX Fix Pack 24 (September 2016 PTF) for 11.1
January 2011 PTF for XL C for AIX, V11.1
August 2011 PTF for XL C for AIX, V11.1
November 2011 PTF for XL C for AIX, V11.1
July 2012 PTF for XL C for AIX, V11.1
XL C for AIX Fix Pack 16 (November 2013 PTF) for 11.1
XL C for AIX Fix Pack 18 (May 2014 PTF) for 11.1
XL C for AIX Fix Pack 19 (August 2014 PTF) for 11.1
XL C for AIX Fix Pack 20 (November 2014 PTF) for 11.1
XL C for AIX Fix Pack 22 (September 2015 PTF) for 11.1

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APAR status

  • Closed as program error.

Error description

  • When compiling the following test case with optimization and
    specifying an architecture setting with -qarch, the compiler is
    encountering an internal error with -O2 and outputting incorrect
    results with the generated binary at -O3.
    
    
       ===== TEST CASE =====
    
    xlc archbug.c -q64 -O2 -qarch=pwr4   <-- Internal Compiler Error
    xlc archbug.c -q64 -O3 -qarch=pwr4   <-- Incorrect result
    
    int two = 2;
    double val[] = {1, 2};
    
    int main(void)
    {
       int  sfirst, i;
       long n, m;
    
       sfirst = 1;
       for (i = 0; i < two; i++)
             if (sfirst)
                { n = val[i]; sfirst = 0; }
             else
                  m = val[i];
    
       if (val[0] == n && val[1] == m)
          printf("Good!\n");
       else
          printf("Bad!\n");
    
       return 0;
    }
    

Local fix

  • Do not use -qarch with affected source code.
    

Problem summary

  • PROBLEM DESCRIPTION:
    While converting an int to float, the compiler is using the
    incorrect source.
    
    USERS AFFECTED:
    Customers using -qarch settings that make use of the PowerPC
    graphics instructions.
    

Problem conclusion

  • The graphics_cvt was corrected and the issue no longer occurs.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IZ79546

  • Reported component name

    XL C/C++ AIX

  • Reported component ID

    5724X1300

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-07-08

  • Closed date

    2010-09-10

  • Last modified date

    2010-09-10

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

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

    LI75760

Fix information

  • Fixed component name

    XL C FOR AIX

  • Fixed component ID

    5724X1200

Applicable component levels

[{"Line of Business":{"code":"LOB57","label":"Power"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGH2K","label":"XL C for AIX"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1"}]

Document Information

Modified date:
06 October 2021