PH31153: STRUCTURED PROGRAMMING MACROS COMPARE AND BRANCH SUPPORT

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• The toolkit Structured Programming Macros should support the
  combined Compare and Branch instructions such as CIJ, available
  since z10.  It would also be helpful to provide "C" and "B"
  mnemonics for "Carry" and "Borrow" conditions following unsigned
   arithmetic operations.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Structured Programming Macros in    *
  *                 HLASM 1.6 Toolkit for z/OS, z/VM and z/VSE   *
  ****************************************************************
  * PROBLEM DESCRIPTION: Structured Programming Macros support   *
  *                      for Compare and Branch instructions     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The HLASM Toolkit structured programming macros do not support
  the use of combined compare-and-branch instructions, which are
  expected to perform better than separate instructions and do not
  affect the condition code.
  
  Also, the macros do not support Carry and Borrow conditions.
  

Problem conclusion

Temporary fix

Comments

• The combined compare-and-branch instructions (available since
  z10) can now be used in condition expressions when using the
  structured programming macros.  This consists of the following
  instructions:
  
    CIB     CGIB    CLIB    CLGIB
    CIJ     CGIJ    CLIJ    CLGIJ
    CRB     CGRB    CLRB    CLGRB
    CRJ     CGRJ    CLRJ    CLGRJ
  
  These instructions should be used without specifying the branch
  address, which will be filled in by the macros.
  
  Example:
  
           IF    (CIJ,R15,GT,4)
  
  Note that these instructions do not set the condition code, so
  if the following term in a condition only tests the condition
  code, this will not test the result of the comparison but rather
  any previous value of the condition code.
  
  Also, carry and borrow conditions following logical arithmetic
  instructions can now be indicated by C for Carry (representing
  CC mask 3) and B for Borrow (representing CC mask 12, including
  support for the Subtract Logical with Borrow instructions).
  
  DOCUMENTATION UPDATES:
  
  The following updates are made to the "Toolkit Feature User's
  Guide", GC26-8710-12:
  
  The following text is added to the summary of changes:
  
    Changes since the twelfth edition:
  
    - Structured programming macro support for compare and branch
      instructions (APAR PH31153)
  
    - Structured programming macro support for Carry and Borrow
      condition mnemonics (APAR PH31153)
  
  In Table 3, "Mnemonics and complements", the second row of the
  is modified as follows to include Carry and Borrow mnemonics:
  
    +-----------------+---------+-------------------+------------+
    |After arithmetic | P, M, Z,| plus, minus, zero,| NP, NM, NZ,|
    |instructions     | O, C, B | overflow, carry,  | NO, NC, NB |
    |                 |         | borrow            |            |
    +-----------------+---------+-------------------+------------+
  
  In the text for "IF macro option C" the following paragraph is
  inserted before the last paragraph starting "In all Option C
  formats":
  
    Combined compare and branch instructions (such as CRB and CIJ)
    may be used provided that the program will be executed only on
    hardware which supports them (IBM z10 and above).  In that
    case the branch address operand should be omitted, as it will
    be filled in automatically by the macros.
  
  END OF DOCUMENTATION UPDATES
  ×**** PE20/11/10 FIX IN ERROR. SEE APAR PH31448  FOR DESCRIPTION
  

APAR Information

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

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

  UI72456 UI72457 UI72458

Modules/Macros

•    ASMMGBLV ASMMGETC ASMMIFPR ASMMPSHI ASMMSP
  

Fix information

• Fixed component name

  HLASM TOOLKIT

• Fixed component ID

  569623401

Applicable component levels

• R16A PSY UI72456

     UP20/11/10 P F011

• R36A PSY UI72457

     UP20/11/30 P 2011

• R6IM PSY UI72458

     UP20/11/09 I 1000

Fix is available

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