LI76129: GENERATED EXECUTABLE FAILS TO RUN AT -O5

XL C/C++ for Linux Fix Pack 9 (August 2013 Update) for 11.1
April 2011 Update for XL C/C++ for Linux, V11.1
July 2011 Update for XL C/C++ for Linux, V11.1
October 2011 Update for XL C/C++ for Linux, V11.1
June 2012 Update for XL C/C++ for Linux, V11.1
October 2012 Update for XL C/C++ for Linux, V11.1
XL C/C++ for Linux Fix Pack 8 (June 2013 Update) for 11.1

APAR status

• Closed as program error.

Error description

• Compilation at -O5 optimization results in the generation of an
  executable that hanges at run-time.
  

Local fix

• Use a lower optimization level.
  

Problem summary

• PROBLEM DESCRIPTION:
  A runtime failure (incorrect results, seg faults, or hang) is
  encountered due to incorrect aliasing.
  
  USERS AFFECTED:
  Users who compile at -O5 optimization.
  

Problem conclusion

• The problem occurs when there is a call in the code to a known
  library functions which returns an address with the value of
  one of the address argument, the compiler may miss the link of
  these two pointers and get their aliasing wrong. The fix is to
  link these kinds of pointers, and thus their aliasing. The
  performance impact should be minimal.
  

Temporary fix

Comments

APAR Information

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

  IZ87170

• 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

• RB10 PSN IZ87170

     UP06/09/13