IBM Support

IV21818: WRONG .MACHINE TAG WITH OPTIMIZATION ENABLED

Fixes are available

August 2012 PTF for XL C for AIX, V12.1
August 2012 PTF for XL C/C++ for AIX, V12.1
November 2012 PTF for XL C for AIX, V12.1
November 2012 PTF for XL C/C++ for AIX, V12.1
March 2013 PTF for XL C for AIX, V12.1
March 2013 PTF for XL C/C++ for AIX, V12.1
XL C/C++ for AIX Fix Pack 4 (June 2013 PTF) for 12.1
XL C/C++ for AIX Fix Pack 5 (September 2013 PTF) for 12.1
XL C/C++ for AIX Fix Pack 7 (January 2014 PTF) for 12.1
XL C for AIX Fix Pack 8 (March 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 8 (March 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 11 (February 2015 PTF) for 12.1
XL C for AIX Fix Pack 12 (May 2015 PTF) for 12.1
XL C/C++ for AIX Fix Pack 12 (May 2015 PTF) for 12.1
XL C/C++ for AIX Fix Pack 13 (August 2015 Update) for 12.1
XL C/C++ for AIX Fix Pack 14 (December 2015 Update) for 12.1
XL C for AIX Fix Pack 15 (April 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 15 (April 2016 Update) for 12.1
XL C for AIX Fix Pack 16 (July 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 16 (July 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 17 (November 2016 Update) for 12.1
XL C for AIX Fix Pack 17 (November 2016 Update) for 12.1
XL C for AIX Fix Pack 18 (February 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 18 (February 2017 Update) for 12.1
XL C for AIX Fix Pack 19 (August 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 19 (August 2017 Update) for 12.1
XL C for AIX Fix Pack 20 (March 2018 Update) for 12.1
XL C/C++ for AIX Fix Pack 20 (March 2018 Update) for 12.1
XL C for AIX Fix Pack 4 (June 2013 PTF) for 12.1
XL C for AIX Fix Pack 5 (September 2013 PTF) for 12.1
XL C for AIX Fix Pack 6 (December 2013 PTF) for 12.1
XL C/C++ for AIX Fix Pack 6 (December 2013 PTF) for 12.1
XL C for AIX Fix Pack 7 (January 2014 PTF) for 12.1
XL C for AIX Fix Pack 9 (July 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 9 (July 2014 PTF) for 12.1
XL C for AIX Fix Pack 10 (October 2014 PTF) for 12.1
XL C/C++ for AIX Fix Pack 10 (October 2014 PTF) for 12.1
XL C for AIX Fix Pack 11 (February 2015 PTF) for 12.1
XL C for AIX Fix Pack 13 (August 2015 Update) for 12.1
XL C for AIX Fix Pack 14 (December 2015 Update) for 12.1
XL C/C++ for AIX Fix Pack 21 (January 2019 Update) for 12.1
XL C for AIX Fix Pack 21 (January 2019 Update) for 12.1

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When compiling an application with the -qarch=pwr7 compile
    option, and enabling optimization level -O2 or -O3, the
    generated .machine pseudo-op incorrectly reads 'pwr6' instead of
    'pwr7'.
    

Local fix

  • Optimization levels -O0, -O4 and -O5 output the correct .machine
    tag.
    

Problem summary

  • PROBLEM DESCRIPTION:
    The .machine tag generated in an output object file depends on
    the highest processor architecture level instruction generated
    by the compiler, not necessarily the -qarch setting.  For
    example, it is possible that compiling with -qarch=pwr7 may
    only
    generate POWER6-level instructions, which would cause a
    .machine
    tag of 'pwr6' to be output.
    
    An issue exists where an inline ASM or mc_func block could
    contain a higher level instruction than generated by the
    compiler, resulting in an incorrect .machine tag.
    
    USERS AFFECTED:
    Applications that depend on the .machine tag in an object file.
    Users of -qarch.
    

Problem conclusion

  • The compiler was modified to force the .machine tag to match
    the
    -qarch setting if an inline ASM or mc_func block is detected.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV21818

  • Reported component name

    XL C FOR AIX

  • Reported component ID

    5725C7100

  • Reported release

    C10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-05-25

  • Closed date

    2012-08-03

  • Last modified date

    2012-08-03

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

    IV19669

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

Fix information

  • Fixed component name

    XL C FOR AIX

  • Fixed component ID

    5725C7100

Applicable component levels

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSCFQM8","label":"Compiler"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"12.1","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
03 August 2012