LI75083: LONG COMPILE TIME WITH -QINFO=ALS

October 2009 Update for XL C/C++ for Linux, V10.1
June 2011 Update for XL C/C++ for Linux, V10.1
XL C/C++ for Linux Fix Pack 8 (January 2014 Update) for 10.1
August 2010 Update for XL C/C++ for Linux, V10.1
January 2011 Update for XL C/C++ for Linux, V10.1
January 2012 Update for XL C/C++ for Linux, V10.1
July 2012 Update for XL C/C++ for Linux, V10.1

APAR status

• Closed as program error.

Error description

• When compiling the following test case with -qinfo=als, it takes
  a relatively long time to compile.
  
  $ time xlC -c -qinfo=als -o QInfo_Problem.o QInfo_Problem.C
  
  real    15m6.80s
  user    14m57.32s
  sys     0m0.12s
  

Local fix

• n/a
  

Problem summary

• Users using -qinfo=als are affected by this issue. Code
  generally in which pointers may point to themselves can reveal
  this issue.
  
  The points-to analysis goes into an infinite
  loop evaluating a points-to analysis for an
  infinite set of nodes, which it believes need to be
  created.
  

Problem conclusion

• Refactoring work was performed to make the
  algorithm more inherently stable with respect to
  infinite recursion.
  

Temporary fix

Comments

APAR Information

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

  IZ43254

• 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

• RA10 PSN IZ43254

     UP06/09/13