Xerox 530 Language And Operations Reference Manual page 76

AI)PENDIX B. EXTENDED SYMBOL DIRECTIVES
In this appendix brackets indicate, optional items. Although a label field entry is indicated as optional, the assembler will
define the label as the current value of the execution location counter and enter it in the appropriate symbol table. A blank
label field indicates that the assembler will ignore a label unless it is the target label of a GOTO search.
The table that follows the functional descriptions summarizes the format of each directive.
Format
[label] ADRL
expression
ASECT
[label] BASE [expression]
[label] BOUND predefine!d absolute expression
label CNAME [predefined expression]
[label] COMMON predefine·d absolute expression
CSECT
DEF
[label] DO
ELSE
END
label EQU
FIN
Llabel] GEN,
field list
predefi ned absol ute expression
[ expression]
predefi ned expression
value list
Function
Generates one word containing the address of the desig-
nated expression. The generated word may be used as an
address I itera I for the symbol.
Declares the following program section to be absolute;
that is, labels on subsequent statements wi II be defi ned
as absolute values.
Designates that the assembler may assume the value " ex -
pression" is contained in the base register.
If
BASE is
omitted or if"expression" is not specified, the assembler
will not automatically impose base-relative addressing.
Advances execution location counter to the next word
multiple of "expression" and advances load location
counter the same number of words.
Designates a procedure name (label) for an immediately
following procedure definition.
Advances the COMMON location counter by "absolute
expression" •
Declares the following program section to be relocatable;
that is, labels on subsequent statements wi II be defined
as relocatable va lues.
Generates each value (Vi) in the list into k words.
If
k is
absent, one-word values are generated.
Declares that each symbol (si) may be referenced by other
(separately assembled) programs.
If expression> 0, generates the code from DO to FIN ex-
pression times, then continues assembly at the statement
following FIN. If expression
<
0, skips all code from DO
to FIN; resumes assembly followi ng FIN.
T errninates the range of an active DO loop; or identifies
the beginning of the alternate sequence of code for an
inactive DO loop.
Terminates the assembly of the object program; optionally
provides the starting point of the program (expression).
EquCltes "Iabel" to the value of "expression".
Terminates a DO loop.
Produces one or more words containing the items in
II
value
list" positioned according to specifications in "field list".
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Appendix B 69