IBM Support

LI76653: LONG COMPILE TIME WITH -O AND -QMAXMEM=-1

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • When a large test case is compiled with -O and -qmaxmem=-1, it
    takes a long time to compile. If -qmaxmem=-1 is removed, it
    finishes much quicker.
    

Local fix

  • n/a
    

Problem summary

  • USERS AFFECTED:
    Users with functions with large basic blocks who compile at -O
    and use -qmaxmem=-1 may be affected by this issue.
    
    PROBLEM DESCRIPTION:
    The compiler take a long time to compile the source file.
    Most of the time was spent in a specific optimization of the
    compiler where it would constantly look for induction variables
    within large loops.
    

Problem conclusion

  • The fix is to put a check in 2 functions in the same file.  The
    functions are both looking for induction variables.
    The check asks if the current function contains loops.  If not
    return at once as there's no point in looking for
    induction variables.
    

Temporary fix

Comments

APAR Information

  • APAR number

    LI76653

  • Reported component name

    XL C/C++ FOR LI

  • Reported component ID

    5724X1400

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2012-02-06

  • Closed date

    2012-02-06

  • Last modified date

    2012-02-06

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

    IV00344

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

Fix information

  • Fixed component name

    XL C/C++ FOR LI

  • Fixed component ID

    5724X1400

Applicable component levels



Document information

More support for: XL C/C++ for Linux

Software version: B10

Reference #: LI76653

Modified date: 06 February 2012