LI73059: USING -O2 CAUSES LINKER ERROR

June 2009 Update for XL C/C++ Advanced Edition for Linux, V9.0
February 2010 Update for XL C/C++ Advanced Edition for Linux, V9.0
February 2011 Update for XL C/C++ Advanced Edition for Linux, V9.0
March 2008 Updates for XL C/C++ Advanced Edition for Linux, V9.0
August 2008 Updates for XL C/C++ Advanced Edition for Linux, V9.0

APAR status

• Closed as program error.

Error description

• When -O2 is used, linker error may occur.
  
  ....
  attrbltn.o:(.data+0x700): undefined reference to `.L1078'
  attrbltn.o:(.data+0x708): undefined reference to `.L1079'
  attrbltn.o:(.data+0x710): undefined reference to `.L1079'
  attrbltn.o:(.data+0x718): undefined reference to `.L1078'
  attrbltn.o:(.data+0x720): undefined reference to `.L1078'
  

Local fix

• Do not use -O2
  

Problem summary

• Users may be affected when they use code that contains both
  inline assembly and switch statements, with optimizations (-O2
  and up).
  
  When the code has inline assembly, an assembly file is
  generated.  Optimizations can remove/combine some cases from
  switch statements and remove the corresponding labels.
  However, these removed labels were still refered to in the
  branch tables, causing undefined errors at link time.
  
  As a result, Linker errors: "undefined reference to `.Ln'"
  (where n is an integer) may occur.
  

Problem conclusion

• A fix will be developed in a future PTF.
  

Temporary fix

Comments

APAR Information

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

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

  LI73302 IZ20700 LI73451 LI73539

Fix information

• Fixed component name

  XL C/C++ RHEL5

• Fixed component ID

  5724S7310

Applicable component levels

• R900 PSY

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