HLASM Language Reference

ACTR Instruction
AGOB—Synonym of the AGO Instruction
For compatibility with some earlier assemblers, High Level Assembler supports the
AGOB symbolic operation code as a synonym of the AGO instruction. However,
you should not use the AGOB instruction in new applications as support for it might
be removed in the future.
ACTR Instruction
The ACTR instruction sets a conditional assembly branch counter either within a
macro definition or in open code. The ACTR instruction can appear anywhere in
open code or within a macro definition.
Each time the assembler processes an AIF or AGO branching instruction in a
macro definition or in open code, the branch counter for that part of the program is
decremented by one. When the number of conditional assembly branches reaches
the value assigned to the branch counter by the ACTR instruction, the assembler
exits from the macro definition or stops processing statements in open code.
By using the ACTR instruction, you avoid excessive looping during conditional
assembly processing.
►►──┬─────────────────┬──ACTR──arithmetic_expression───────────────►◄
└─sequence_symbol─┘
sequence_symbol
is a sequence symbol.
arithmetic_expression
is an arithmetic expression used to set or reset a conditional assembly branch
counter.
A conditional assembly branch counter has a local scope; its value is decremented
by AGO and successful AIF instructions, and reassigned only by ACTR instructions
that appear within the same scope. Thus, the nesting of macros has no effect on
the setting of branch counters in other scopes. The assembler assigns a branch
counter for open code and for each macro definition. In the absence of an ACTR
instruction, a default value of 4096 is assigned.
Branch Counter Operations
Within the scope of a branch counter, the following occurs:
1. Each time an AGO or AIF branch is executed, the assembler checks the
branch counter for zero or a negative value.
2. If the count is not zero or negative, it is decremented by one.
3. If the count is zero or negative, the assembler takes one of two actions:
a. If it is processing instructions in open code, the assembler processes the
remainder of the instructions in the source module as comments. Errors
discovered in these instructions during previous passes are flagged.
b. If it is processing instructions inside a macro definition, the assembler
terminates the expansion of that macro definition and processes the next
sequential instruction after the calling macro instruction. If the macro
definition is called by an outer macro instruction, the assembler processes
394 HLASM V1R5 Language Reference