PH48129: INCORRECT OUTPUT WHEN -O2

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When compiling the provided testcase with -O2, the resulting exe
  produces an incorrect output as showing below.
  
  ===== ACTUAL OUTPUT:
  $ xlC testprms.cpp prmparse.cpp -O2
  
  $./a.out
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0BB34, exprLen=8
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0BB3C, exprLen=15
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0BB43, exprLen=4
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0BB47, exprLen=11
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0BB4E, exprLen=7
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0BB55, exprLen=12
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0BB5A, exprLen=9
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0BB63, exprLen=14
  parm=2, exprVal=25C0BB3C, exprLen=15, textVal=25C0BB3C,
  textLen=6, data="LONDON,MDL=MODEL"
  parm=5, exprVal=25C0BB47, exprLen=11, textVal=25C0BB47,
  textLen=6, data="MODEL5,USERID=AB"
  parm=6, exprVal=25C0BB63, exprLen=14, textVal=25C0BB63,
  textLen=5, data="BAKER           "
  parm=7, exprVal=25C0BB55, exprLen=12, textVal=25C0BB55,
  textLen=4, data="ABLE,PASSWORD=BA"
  
  *** Error - incorrect behaviour was observed.
  $
  
  ===== EXPECTED OUTPUT:
  $ xlC testprms.cpp prmparse.cpp
  $./a.out
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0B6D4, exprLen=8
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0B6D4, exprLen=15
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0B6E3, exprLen=4
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0B6E3, exprLen=11
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0B6EE, exprLen=7
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0B6EE, exprLen=12
  Line 260: state=nameSearch
  Line 275: exprPtr=25C0B6FA, exprLen=9
  Line 260: state=valueSearch
  Line 275: exprPtr=25C0B6FA, exprLen=14
  parm=2, exprVal=25C0B6D4, exprLen=15, textVal=25C0B6DC,
  textLen=6, data="CLINODE=LONDON,M"
  parm=5, exprVal=25C0B6E3, exprLen=11, textVal=25C0B6E7,
  textLen=6, data="MDL=MODEL5,USERI"
  parm=6, exprVal=25C0B6FA, exprLen=14, textVal=25C0B703,
  textLen=5, data="PASSWORD=BAKER  "
  parm=7, exprVal=25C0B6EE, exprLen=12, textVal=25C0B6F5,
  textLen=4, data="USERID=ABLE,PASS"
  
  Correct behaviour was observed.
  $
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: XLC Users using the OPTIMIZE option.         *
  ****************************************************************
  * PROBLEM DESCRIPTION: The optimizer may incorrectly optimize  *
  *                      a conditional statement to produce an   *
  *                      incorrect/undefined result when         *
  *                      assigning value to an undefined (but    *
  *                      declared) variable.                     *
  ****************************************************************
  * RECOMMENDATION: Install the PTF                              *
  ****************************************************************
  N/A
  

Problem conclusion

• The user should install the 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:

Modules/Macros

• CCNECICS CCNECWI  CCNED240 CCNEDSCT CCNEDWRT CCNEFILT CCNEHIFC
  CCNEIPA3 CCNEIPAO CCNEMDEP CCNEOPTP CCNEP    CCNEPP   CCNETBY
  CCNMSGE  CCNMSGT  CCNQIPA
  

Fix information

• Fixed component name

  C/C++ FOR MVS

• Fixed component ID

  56551210A

Applicable component levels

• R7C0 PSY UI81828

     UP22/09/07 P F209

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.