LI76959: MISSING ALIAS IN IPA/PDF BUILD

September 2012 Update for XL C/C++ for Linux, V12.1
April 2013 Update for XL C/C++ for Linux, V12.1
XL C/C++ for Linux Fix Pack 8 (October 2015 Update) for 12.1
December 2012 Update for XL C/C++ for Linux, V12.1
XL C/C++ for Linux Fix Pack 4 (October 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 5 (December 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 6 (February 2014 Update) for 12.1
XL C/C++ for Linux Fix Pack 7 (May 2014 Update) for 12.1

APAR status

• Closed as program error.

Error description

• When compiling a large application with ipa/pdf, the resulting
  exe had missing aliasing information leading to incorrect
  output.
  
  It is narrowned down to this sequence of
  code:
  
    816:      L1Z
  gr1504=#BIT_@2OLshd.pbrudi9D<id804:d0:l1>(gr1501,0)
  2951,49726,49704
      0:      DIRCTIV   issue_cycle,6,1009
  49726,56279,2951
      0:      DIRCTIV   issue_cycle,5,1
  56279,2948,49726
    813:      L8
  *gr1503=(__uAB_TYPE).pbagXXX@0.rns95.(gr3,0)    2948,2949,56279
    813:      ST8       @2OLshd.pbrudi9D(gr1501,0)=gr1503
  2949,2950,2948
  
  the first and last instructions have been reordered by the
  scheduler but they have the same address. These two dr's are not
  aliased.
  

Local fix

• n/a
  

Problem summary

• USERS AFFECTED:
  Users of IPA at -O4 and above may be affected by this issue.
  
  PROBLEM DESCRIPTION:
  The issue is that the compiler generates missing aliasing
  information with IPA/PDF.
  

Problem conclusion

• The compiler generates correct aliasing information needed for
  IPA outlining.
  

Temporary fix

Comments

APAR Information

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

  IV22789

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

Fix information

• Fixed component name

  XL C/C++ FOR LI

• Fixed component ID

  5725C7300

Applicable component levels

• RC10 PSN IV22789

     UP06/09/13