IBM Support

LI75897: LONG COMPILE TIME IN XLCCODE WITH -O3

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When compiling a large program using -O3, the complile time
    drastically increases than compared to compiling t -O2 or
    without any optimizations.
    
    eg: When using -qphsinfo, the detailed compile time output can
    be observed:
    $xlC_r -qoptimize=3 -qphsinfo
    -qtmplparse=warn -q64 -qfuncsect -qrtti=all
    -qlanglvl=newexcp -qeh=v6 -qutf -qtabsize=4 -D__IBMCPP_TR1__
    -qtbtable=full -c -o BulkImport.o BulkImport.i -+
    
    Front End - Phase Ends;   8.405/  8.413
    IPA       - Phase Ends;  74.070/ 74.250
    W-TRANS   - Phase Ends;  10.480/ 10.490
    OPTIMIZ   - Phase Ends; 6636.230/6692.010
    REGALLO   - Phase Ends; 186.540/249.420
    AS        - Phase Ends;   0.130/  0.140
    IPA       - Phase Ends;  74.070/ 74.250
    $
    

Local fix

  • N/A
    

Problem summary

  • USERS AFFECTED:
    User compiling a large program with optimization may be
    affected by this issue.
    
    PROBLEM DESCRIPTION:
    The compile time problem was caused by the alias information
    generation for the function descriptor during a specific
    optimization within xlCcode.
    

Problem conclusion

  • The compiler has been fixed to reduce some overheads in the
    computation of the aliasing of the function descriptor.
    

Temporary fix

Comments

APAR Information

  • APAR number

    LI75897

  • Reported component name

    XL C/C++ RHEL52

  • Reported component ID

    5724U8310

  • Reported release

    A10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2011-01-27

  • Closed date

    2011-01-27

  • Last modified date

    2011-01-27

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

    IZ83459

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

Fix information

  • Fixed component name

    XL C/C++ RHEL52

  • Fixed component ID

    5724U8310

Applicable component levels

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSJT9L","label":"XL C\/C++"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"A.1","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}}]

Document Information

Modified date:
15 October 2021