PH08642: NEW FUNCTION: Improved NUMCHECK performance

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• Some users wish to use NUMCHECK in production to detect invalid
  data. As NUMCHECK checks every data item of the specified types
  each time they're used, using NUMCHECK can significantly
  decrease performance.
  

Local fix

• Use NUMCHECK for testing only, not production
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL V6.2 wanting to    *
  *                 use NUMCHECK to detect invalid data in       *
  *                 their production environment.                *
  ****************************************************************
  * PROBLEM DESCRIPTION: Some users wish to use NUMCHECK in      *
  *                      production to detect invalid data. As   *
  *                      NUMCHECK checks every data item of the  *
  *                      specified types each time they're       *
  *                      used, using NUMCHECK can significantly  *
  *                      decrease performance.                   *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF.                      *
  ****************************************************************
  The initial version of NUMCHECK is thorough and guarantees
  accuracy, but since it checks every possible case, even those
  that are redundant, it is bad for performance.
  

Problem conclusion

Temporary fix

Comments

• The compiler has a new optimization that analyzes the program
  for NUMCHECKs that are redundant, because the value is known to
  be good or bad, or because a value has previously been checked.
  This increases the performance of NUMCHECK.
  
  Because some checks are removed, there will be
  fewer runtime messages produced by NUMCHECK. Invalid data that
  is preserved over multiple COBOL statements will still be
  checked at least once.
  
  Using NUMCHECK(ABD), for checks where the data is known invalid
  at compile time, the compiler removes the check and issues an
  error message.
  
  Using NUMCHECK(MSG), for checks where the data is known invalid
  at compile time, the compiler does not remove the check and
  issues a warning message. That check will fail, and produce a
  message, at runtime.
  
  The full analysis required to remove the redundant checks can
  take a lot of compilation time for larger programs. At OPT(0),
  a simpler version of the analysis is run, in order to keep
  compilation time low; at OPT(1|2), a more expensive analysis is
  run. Programs compiled with NUMCHECK at OPT(1|2) may perform
  better than programs compiled with NUMCHECK at OPT(0) because
  the more expensive analysis at OPT(1|2) may remove more
  redundant checks than the cheaper analysis at OPT(0). Because
  of this, there may be more runtime messages shown using
  NUMCHECK(MSG) at lower OPT levels than higher OPT levels.
  
  Checks where data is known invalid at compile time may only be
  able to be detected by the compiler at higher OPT levels, and
  so there may be more compile time errors, using NUMCHECK(ABD),
  or messages, using NUMCHECK(MSG), at higher OPT levels.
  

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 IGYCLIBH IGYCLIBO IGYCLIBR IGYCLSTR IGYCLVL0
  IGYCLVL1 IGYCLVL2 IGYCLVL3 IGYCLVL8 IGYCMALL IGYCOB2  IGYCOB2E
  IGYCOPI  IGYCOPT  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  IGYZQDRV
  IGYZQENU IGYZQJPN
  

Fix information

• Fixed component name

  ENT COBOL FOR Z

• Fixed component ID

  5655EC600

Applicable component levels

• R620 PSY UI62019

     UP19/03/29 P F903

• R621 PSY UI62020

     UP19/03/29 P F903

• R622 PSY UI62021

     UP19/03/29 P F903

• R62H PSY UI62022

     UP19/03/29 P F903

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.