PH41632: PERFORMANCE OF INITIALIZE OR MOVE STATEMENTS MAY BE WORSE IN COBOL 6.3 THAN IN COBOL 6.2

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Performance of INITIALIZE or MOVE statements may be worse in
  COBOL 6.3 than in COBOL 6.2
  

Local fix

• None.  Apply PTF
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL 6.3 compiling      *
  *                 programs at OPT(1|2) with INITIALIZE         *
  *                 statements or consecutive MOVE statements    *
  *                 that initialize or MOVE SPACES (or similar   *
  *                 values that repeat the same single byte of   *
  *                 data) to consecutive alphanumeric or USAGE   *
  *                 DISPLAY data items that are at between 9     *
  *                 and 31 bytes each.                           *
  ****************************************************************
  * PROBLEM DESCRIPTION: Performance of INITIALIZE or MOVE       *
  *                      statements may be worse in COBOL 6.3    *
  *                      than in COBOL 6.2                       *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF                       *
  ****************************************************************
  The compiler will attempt to merge stores of constant values to
  sequential receivers, whether generated by individual
  consecutive MOVE statements, a group MOVE, or INITIALIZE
  statements, into single larger moves, as this gives better
  performance than individual smaller moves. In Enterprise COBOL
  6.3, the compiler was changed to take advantage of further
  performance improvements using ripple copies: where a single
  byte of data is written to a receiver and then that byte is
  copied to successive bytes of that and possibly other
  consecutive receivers. In cases where the compiler identified
  possible ripple-copy opportunities in the middle of a sequence
  of consecutive constant stores, the compiler was interrupting
  the sequence of stores while also failing to combine the stores
  involved in the ripple copy, leading to an increased number of
  store operations compared to COBOL 6.2.
  

Problem conclusion

• The compiler was fixed to combine stores into ripple copies, if
  a sequence is found in the middle of consecutive stores, only
  if the combined size of the ripple-copy items totals 32 bytes.
  If the combined size is less than 32 bytes, the compiler was
  also fixed to still consider the ripple-copy stores as part of
  a longer sequence of consecutive stores to combine into one
  larger store.
  

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

• 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 UI78163

     UP21/11/25 P F111

• R631 PSY UI78164

     UP21/11/25 P F111

• R632 PSY UI78165

     UP21/11/25 P F111

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.