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Assembly Language Fundamentals
are used to designate which conditions are "set" during the assembly. By including one or
more of these conditions, all conditional assembly statements predicated upon that condition
are assembled. For example, if the following statement is executed-
IAS3EMBLE Retrieve;A
then any occurrence of conditional assemblies based on "A" are assembled. Also, any condi-
tional assemblies based on B through H are not assembled, since those conditions were not
included in the options for the IASSEMBLE statement.
The conditional assembly sections are delimited by pseudo-instructions. A conditional section
begins with one of the following -
IFE:
IFe
IFE
IF(::;
IFH
and it concludes with -
>< IF
In addition to the lettered conditions, a numeric condition can be tested by using an IFP
pseudo-instruction. It has the form -
I FF' {absolute expression}
The condition is considered true if {absolute expression} evaluates as a positive value. It should
be noted that this is an assembly-time construct, meaning that the variables contained in the
expression are evaluated at the time of assembly.
The IFP instruction performs in the same manner as the IFA through IFH instructions. It also
terminates with the XIF instruction.
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