PH53882: UNEXPECTED BEHAVIOR WHEN USING ARITH(EXTEND) WITH EXPONENTIATION

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When performing calculations of R ** S, a base number raised to
  a fractional power, behavior is different between using
  ARITH(EXTEND) and ARITH(COMPAT) in certain cases:
  - Zero raised to zero power >> Without SIZE ERROR clause, the
  value returned is 1, and a message is issued.  However, with
  ARITH(EXTEND), result is CEE2020E.
  - A negative number raised to a fractional power  >>  Without
  SIZE ERROR, the absolute value of the base is used, and a
  message is issued.  With ARITH(EXTEND), result is CEE2006E.
  

Local fix

• Compile with ARITH(COMPAT), or use ON SIZE ERROR phrase
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL 5 and later        *
  *                 releases running programs compiled           *
  *                 with ARITH(EXTEND) and using                 *
  *                 COMP-2 data types to perform                 *
  *                 exponentiation calculations.                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: When the On Size Error clause is not    *
  *                      defined, results from exponentiation    *
  *                      calculations for programs compiled with *
  *                      ARITH(EXTEND) behave differently from   *
  *                      programs compiled with ARITH(COMPAT)    *
  *                      by producing LE error messages in       *
  *                      cases where COBOL Runtime warning or    *
  *                      error messages are expected.            *
  ****************************************************************
  * RECOMMENDATION: Install the provided PTF.                    *
  ****************************************************************
  There was a logic error in the COBOL Runtime routine for
  performing exponentiation calculations using COMP-2 in
  three cases. When exponentiation calculations were performed
  using COMP-2 without ON SIZE ERROR, the exponentiation
  behaviour differed between ARITH(COMPAT) and
  ARITH(EXTEND) in 3 cases.
  
  Case 1 - Base = negative, Power = fractional (eg: 1.24)
  Case 2 - Base = zero, Power = zero
  Case 3 - Base = zero, Power = negative
  
  In the cases listed above, LE error messages were
  incorrectly generated causing the program to end.
  The correct behavior is that the following
  Run-time messages are generated for these cases:
  
  Case 1 - IGZ0048W
  Case 2 - IGZ0049W
  Case 3 - IGZ0050S
  
  COB0501T/K COB0502T/K COB0601T/K COB0602T/K COB0603T/K
  COB0604T/K
  

Problem conclusion

• The problem in the COBOL Runtime has been corrected.
  The problem was resolved by improving the logic used to
  perform exponentiation calculates. Now Run-time
  messages will be printed in these three cases:
  
  Case 1 - Base = negative, Power = fractional (eg: 1.24)
  Case 2 - Base = zero, Power = zero
  Case 3 - Base = zero, Power = negative
  
  This would ensure that ARITH(COMPAT) and
  ARITH(EXTEND) both have the same behavior when
  performing exponentiation calculation with COMP-2
  and without On Size Error.
  

Temporary fix

Comments

• ×**** PE23/10/18 FIX IN ERROR. SEE APAR PH57638  FOR DESCRIPTION
  ×**** PE23/10/18 FIX IN ERROR. SEE APAR PH57638  FOR DESCRIPTION
  ×**** PE23/10/18 FIX IN ERROR. SEE APAR PH57638  FOR DESCRIPTION
  

APAR Information

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

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

  UI92335 UI92336

Modules/Macros

• IGZCEV4  IGZCJNI2 IGZLLIBV IGZXAPI  IGZXCA31 IGZXCDA  IGZXD24
  IGZXDMR  IGZXJNI2 IGZXLPIO IGZXLPKA IGZXLPKB IGZXLPKC IGZXLPKD
  IGZXLPKE IGZXLPKF IGZXLPKG IGZXPK2  IGZXQXPQ
  

Fix information

• Fixed component name

  LE ENT COBOL LI

• Fixed component ID

  568819812

Applicable component levels

• R7C0 PSY UI92335

     UP23/06/28 P F306

• R7D0 PSY UI92336

     UP23/06/28 P F306

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.