PH46868: INCORRECT EVALUATION OF SETB EXPRESSIONS CONTAINING EQ FOLLOWED BY NOT

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A SETB expression with a relational operator followed by NOT
  triggers a forced evaluation of the expression in the wrong
  order causing incorrect results.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of HLASM for z/OS, z/VM, z/VSE and     *
  *                 Linux                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: Incorrect evaluation of SETB            *
  *                      expressions containing EQ followed      *
  *                      by NOT.                                 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  1. In a conditional assembly logical (SETB) expression or
     arithmetic (SETA) expression, NOT may be processed
     incorrectly.  If NOT is immediately preceded by another
     operator of higher or equal priority (including a relation
     such as EQ, or an arithmetic operator, or NOT itself) then
     incorrect results may be produced because the preceding part
     of the expression including that operator at that level is
     ignored.
  2. Operation code attribute O' is allowed as a first-level macro
     operand, but fails with error ASMA088E when used as a list
     item in parentheses. When operation code attribute O' is used
     as an operand in a macro call with left and right
     parenthesis, it is being parsed without taking the O'
     attribute into account, so the single quote looks like the
     start of a quoted string, and the parenthesis is taken to be
     within the string causing incorrect results. Also, the
     documentation incorrectly said in some places that this
     notation was not allowed in open code, but it has always been
     allowed in open code since the opereration code attribute was
     introduced (in HLASM 1.2 in 1994).
  

Problem conclusion

• 1. The code is fixed to evaluate the SETB expression in the
     correct order.
  
  2. The Operation code attribute O' is now parsed as a attribute
     reference in a macro operand call.
  

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:

  UI81148 UI81147 UI81149

Modules/Macros

•    ASMAINFO ASMA1Q   ASMA1U   ASMA9Z
  

Fix information

• Fixed component name

  HLASM MVS, VM &

• Fixed component ID

  569623400

Applicable component levels

• R160 PSY UI81148

     UP22/06/25 P F206

• R360 PSY UI81147

     UP22/06/24 P 2206

• R689 PSY UI81149

     UP22/06/24 I 1000

Fix is available

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