PH29543: Users of ENTERPRISE COBOL 6.3 compiling with OPT(1|2) where the programs contain IF or EVALUATE statements

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• PROBLEM DESCRIPTION: The compiler may incorrectly remove the
  comparison and the code path that would execute when the
  condition is
  matched, instead forcing execution to
  continue on
  the code path when the
  data
  item matches none of the constant
  values.
  
  USERS AFFECTED: Users of Enterprise COBOL 6.x compiling
  with OPT(1|2) where the programs contain IF
  or EVALUATE
  statements that compare a
  single
  data item to several constant
  values where
  the constants and data item are at most
  four bytes
  long, the data item has a known
  value at the point of
  comparison, and that
  value matches one of the constants being
  compared. This may also occur if the
  comparison is within a
  paragraph that is
  PERFORMed, the paragraph is inlined, and
  shortly before the PERFORM statement, the
  data item is assigned
  a value matching one
  of the constants being compared.
  
  KNOWN IMPACT:
  The compiler incorrectly removes code, leading to indeterminate
  incorrect behaviour
  

Local fix

• BYPASS/CIRCUMVENTION:
  WORKAROUND/CIRCUMVENTION: Compile with OPT(0), or possibly with
  NOINLINE.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL 6.3 compiling      *
  *                 with OPT(1|2) where the programs contain IF  *
  *                 or EVALUATE statements that compare a        *
  *                 single                                       *
  *                 data item to several constant values where   *
  *                 the constants and data item are at most      *
  *                 four bytes long, the data item has a known   *
  *                 value at the point of comparison, and that   *
  *                 value matches one of the constants being     *
  *                 compared. This may also occur if the         *
  *                 comparison is within a paragraph that is     *
  *                 PERFORMed, the paragraph is inlined, and     *
  *                 shortly before the PERFORM statement, the    *
  *                 data item is assigned a value matching one   *
  *                 of the constants being compared.             *
  ****************************************************************
  * PROBLEM DESCRIPTION: The compiler may incorrectly remove the *
  *                      comparison and the code path that       *
  *                      would execute when the condition is     *
  *                      matched, instead forcing execution to   *
  *                      continue on the code path when the      *
  *                      data                                    *
  *                      item matches none of the constant       *
  *                      values.                                 *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF                       *
  ****************************************************************
  When comparing the known value of the data item to the known
  constant values, the compiler was comparing up to 32 bits of
  data as a 64-bit compare. If the leftmost bit of the data item
  is 1, the 32-bit value was expanded to 64 bits by setting the
  leftmost 32 bits to 1 (that is, x'FFFFFFFF'), while when the
  constants were expanded to 64 bits, the leftmost 32 bits were
  all set to 0 (x'00000000'). The compiler then compared these
  two values, and as the leftmost 32 bits in each didn't match,
  the compiler incorrectly concluded that the data item didn't
  match any of the values to which it was being compared.
  

Problem conclusion

• The compiler was fixed to compare 32-bit constants as 32 bits,
  instead of expanding to 64 bits.
  

Temporary fix

Comments

APAR Information

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

  PH28786

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

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 IGYCOB2  IGYCOPI  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 UI71591

     UP20/09/27 P F009

• R631 PSY UI71592

     UP20/09/26 P F009

• R632 PSY UI71593

     UP20/09/26 P F009

• R63H PSY UI71594

     UP20/09/26 P F009

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.