PH51996: Comparison of unsigned to signed halfword binary items produces an incorrect result

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Under optimization with compile time evaluation of the compare,
  the optimizer treats the unsigned halfword (PIC 4(9) COMP-5)
  item as signed, perhaps leading to a
  
  IGYCB7300-W The code from lines nn.n in program 'program' was
          safely removed by the optimizer.
  
  compile time diagnostic, for example of the wrong clause of an
  if statement.
  
  At OPT(0), or OPT(1|2) where compile time evaluation is not
  possible, the unsigned operand is incorrectly loaded with a sign
  extending LH (LOAD HALFWORD) instruction.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL 6.3 compiling and  *
  *                 running programs that contain a comparison   *
  *                 between two operands that meet the following *
  *                 conditions: 1) The operands are USAGE COMP-5 *
  *                 (or USAGE BINARY/COMP/COMP-4 and the program *
  *                 is compiled with the TRUNC(BIN) option). 2)  *
  *                 The operands have the same decimal and       *
  *                 integer precision. 3) One of the operands is *
  *                 signed and the other is unsigned. 4) The     *
  *                 value in the unsigned item has its           *
  *                 high-order bit set and the value in the      *
  *                 signed item is positive.                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: Incorrect comparison result at run      *
  *                      time.                                   *
  ****************************************************************
  * RECOMMENDATION: Apply the IBM-provided PTF.                  *
  ****************************************************************
  Under very specific conditions, comparisons between two binary
  operands that have truncation at hardware boundaries (instead of
  decimal digit boundaries) and have different signedness
  properties were performed with an incorrect precision.
  

Problem conclusion

• The compiler was updated to ensure that comparisons between
  binary operands with hardware, word-size based truncation and
  different signedness properties are always performed with the
  proper precision.
  

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:

  PH52707 UI90994 UI90995 UI90996

Modules/Macros

• IGY8RWTU IGYCASMB IGYCCBE  IGYCCCRT IGYCCICS IGYCCSRV IGYCDGEN
  IGYCDIAG IGYCDMAP IGYCEN$0 IGYCEN$1 IGYCEN$2 IGYCEN$3 IGYCEN$4
  IGYCEN$5 IGYCEN$8 IGYCEN$D IGYCEN$R IGYCFGEN IGYCFREE IGYCINIT
  IGYCJA$0 IGYCJA$1 IGYCJA$2 IGYCJA$3 IGYCJA$4 IGYCJA$5 IGYCJA$8
  IGYCJA$D IGYCJA$R IGYCLIBR IGYCLSTR IGYCLVL0 IGYCLVL1 IGYCLVL2
  IGYCLVL3 IGYCLVL8 IGYCMALL IGYCOSCN IGYCPGEN IGYCRCTL IGYCRDPR
  IGYCRDSC IGYCREAL IGYCRWT  IGYCSCAN IGYCSIMD IGYCUE$0 IGYCUE$1
  IGYCUE$2 IGYCUE$3 IGYCUE$4 IGYCUE$5 IGYCUE$8 IGYCUE$D IGYCUE$R
  IGYCXREF IGYDRV   IGYEQCWI IGYMSGE  IGYMSGK  IGYMSGT  IGYQCBE
  IGYQSPLT IGYZQEN6 IGYZQENU IGYZQJP6 IGYZQJPN
  

Fix information

• Fixed component name

  ENT COBOL FOR Z

• Fixed component ID

  5655EC600

Applicable component levels

• R630 PSY UI90994

     UP23/03/28 P F303

• R631 PSY UI90995

     UP23/03/28 P F303

• R632 PSY UI90996

     UP23/03/28 P F303

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.