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Document:	VAX-11 MACRO Language Reference Manual
Order Number:	AA-D032C-TE
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Pages:	187
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VAX-11 MACRO
Language Reference Manual
Order No. AA-D032C-TE

March 1980

This document describes the assembly language supported by VAX/VMS. All
symbols, expressions, addressing modes, and directives are detailed. No prior
knowledge of the VAX-11 MACRO assembler is assumed.

VAX-11 MACRO
Language Reference Manual
Order No. AA-D032C-TE

SUPERSESSION/UPDATE INFORMATION: This revised document supersedes
the VAX-11 MACRO Language
Reference Manual (Order No.
AA-D032B-TE)
OPERATING SYSTEM AND VERSION:

VAX/VMS V02

SOFTWARE VERSION:

VAX-11 MACRO V02

To order additional copies of this document, contact the Software Distribution
Center, Digital Equipment Corporation, Maynard, Massachusetts 01754

digital equipment corporation · maynard, massachusetts

First Printing, August 1978
Revised, February 1979
Revised, March 1980
The information in this document is subject to change without notice
and should not be construed as a commitment by Digital Equipment
Corporation. Digital Equipment Corporation assumes no responsibility
for any errors that may appear in this document.
The software described in this document is furnished under a license
and may only be used or copied in accordance with the terms of such
license.
No responsibility is assumed for the use or reliability of software on
equipment that is not supplied by DIGITAL or its affiliated companies.

@ 1978, 1979, 1980 by Digital Equipment Corporation.

The postage prepaid READER'S COMMENTS form on the last page of this
document requests the user's critical evaluation to assist us in
preparing future documentation.
The following are trademarks of Digital Equipment Corporation:
DIGITAL
DEC
PDP
DEC US
UNIBUS
COMPUTER LABS
CO MT EX
DDT
DEC COMM
ASSIST-11
VAX
DECnet
DATATRIEVE

DECsystem-10
DECtape
DIBOL
EDU SYSTEM
FLIP CHIP
FOCAL
IND AC
LAB-8
DECSYSTEM-20
RTS-8
VMS
IAS
TRAX

MASSBUS
OMNIBUS
OS/8
PHA
RSTS
RSX
TYPESET-8
TYPESET-11
TMS-11
ITPS-10
SB!
PDT

CONTENTS

Page

vii

PREFACE
CHAPTER

INTRODUCTION

1-1

CHAPTER

MACRO SOURCE STATEMENT FORMAT

2-1

2.1
2.2
2.3

2.4

LABEL FIELD
OPERATOR FIELD
OPERAND FIELD
COMMENT FIELD

2-2
2-3
2-3
2-4

THE COMPONENTS OF MACRO SOURCE STATEMENTS

3-1

3.1
3.2
3.2.1
3.2.2
3.2.3
3.3
3.3.1
3.3.2
3.3.3
3.4
3.5
3.6

3-1
3-3
3-3

3.7
3.7.1
3.7.2
3.7.3
3.7.4
3.8
3.9

CHARACTER SET
NUMBERS
Integers
Floating-Point Numbers
Packed Decimal Strings
SYMBOLS
Permanent Symbols
User-defined Symbols and Macro Names
Determining Symbol Values
LOCAL LABELS
TERMS AND EXPRESSIONS
UNARY OPERATORS
Radix Control Operators
Textual Operators
ASCII Operator
Register Mask Operator
Numeric Control Operators
Floating-Point Operator
Complement Operator
BINARY OPERATORS
Arithmetic Shift Operator
Logical AND Operator
Logical Inclusive OR Operator
Logical Exclusive OR Operator
DIRECT ASSIGNMENT STATEMENTS
CURRENT LOCATION COUNTER

ADDRESSING MODES

4-1

4.1

GENERAL REGISTER MODES
Register Mode
Register Deferred Mode
Autoincrement Mode
Autoincrement Deferred Mode
Autodecrement Mode
Displacement Mode
Displacement Deferred Mode
Literal Mode

4-1

CHAPTER

3.6.1
3.6.2
3.6.2.1
3.6.2.2
3.6.3

3.6.3.1
3.6.3.2

CHAPTER

4 .1.1

4.1.2
4 .1. 3
4 .1. 4

4.1.5
4 .1. 6
4 .1. 7
4 .1.8

iii

3-4
3-5
3-5
3-5

3-'1
3-'1
3-7
3-9
3-11
3-12
3-13
3-13
3-13
3-14

3-14
3-15

3-15
3-lh
3-lh
3-17

3-17
3-17

3-18

4-4
4-4
4-5
4-5
4-'1
4-6
4-8
4-9

CONTENTS

Page

CHAPTER

4.2
4.2.1
4.2.2
4.2.3
4.2.4
4.2.5
4.3
4.4

PROGRAM COUNTER MODES

INDEX MODE
BRANCH MODE

4-10
4-10
4-11
4-12
4-12
4-13
4-14
4-17

GENERAL ASSEMBLER DIRECTIVES

5-1

.ADDRESS
.ALIGN
.ASCix
.ASCII
.ASCIC
.ASCID
.ASCIZ
.BLKx
.BYTE
.CROSS
.NOCROSS
.DEBUG
.DEFAULT
.D FLOATING .DOUBLE
.DISABLE
.ENABLE
.END
.ENDC
.ENTRY
.ERROR
.EVEN
.EXTERNAL
.F FLOATING .FLOAT
.G-FLOATING
.GLOBAL
.H FLOATING
.!DENT
.IF
.IF x

5-3
5-4
5-6
5-7
5-7
5-8
5-8
5-9
5-11
5-12
5-14
5-15
5-16
5-17
5-17
5-20
5-20
5-21
5-23
5-24
5-24
5-25
5-26
5-27
5-28
5-29
5-30
5-33
5-36
5-37
5-38
5-39
5-39
5-40
5-40
5-41
5-41
5-42
5-44
5-44
5-45
5-46
5-51
5-52
5-53
5-54
5-55

Relative Mode
Relative Deferred Mode
Absolute Mode
Immediate Mode
General Mode

.IIF
.LIST
.LONG
.MASK
.NLIST
.NOCROSS
.NOSHOW
.OCTA
.ODD
.OPDEF
.PACKED
.PAGE
• PRINT
.PSECT
.QUAD

.REFn
.RESTORE PSECT
.SAVE PSECT
.SHOW- .NOSHOW

CONTENTS

Page

CHAPTER

.SIGNED BYTE
.SIGNED-WORD
.SUBTITLE
.TITLE
.TRANSFER
.WARN
.WEAK
.WORD

5-57
5-58
5-60
5-61
5-fi2
5-fi5
5-66
5-67

MACROS

6-1

6.1

6-2

6 .1.1
6 .1. 2
6 .1. 3
6 .1.4
0 .1. 5

ARGUMENTS IN MACROS
Default Values
Keyword Arguments
String Arguments
Argument Concatenation
Passing Numeric Values of Symbols
6.1.6
Created Local Labels
Macro String Operators
6.1.7
6.1.7.1
%LENGTH Operator
6.1.7.2
%LOCATE Operator
%EXTRACT Operator
6.1.7.3
6.2
MACRO DIRECTIVES
.ENDM
.ENDR
• IRP
• IRPC
• LIBRARY
.MACRO
.MCALL
.MDELETE
.MEXIT
.NARG
.NCHR
.NTYPE
.REPEAT

fi-3
fi-3

6-22
6-23
fi-24
6-25
fi-26
6-28

APPENDIX

ASCII CHARACTER SET

A-1

APPENDIX

VAX-11 MACRO ASSEMBLER DIRECTIVES AND
LANGUAGE SUMMARY

B-1

n-7

6-7

n-8

6-9
n-10
6-11

6-13
n-13
6-13

n-14
fi-16
6-18
6-19
~-21

B.4

ASSEMBLER DIRECTIVES
SPECIAL CHARACTERS
OPERATORS
Unary Operators
Binary Operators
Macro String Operators
ADDRESSING MODES

PERMANENT SYMBOL TABLE

C-1

C.l
C.2

OPCODES (ALPHABETIC ORDER)
OPCODES (NUMERIC ORDER)

C-1
C-8

B.l
B.2
B.3
B.3.1
B.3.2

B.3.3
APPENDIX

6-4
6-6

B-1
B-7

B-9
B-9
B-10
B-10
B-11

CONTENTS

Page
APPENDIX

HEXADECIMAL/DECIMAL CONVERSION

D-1

D.l

HEXADECIMAL TO DECIMAL
DECIMAL TO HEXADECIMAL
POWERS OF 2 AND 16

D-1
D-1

D.2
D.3

INDEX

D-2

Index-1

FIGURES
FIGURE

5-1

Using Transfer vectors

5-63

TABLES
TABLE

3-1
3-2

3-3
3-4

4-1
4-2
4-3
5-1
5-2
5-3

5-4
5-5
5-6

5-7
6-1
A-1
B-1
B-2
B-3

B-4
B-5
B-6
D-1

Special Characters Used in VAX-11 MACRO
Statements
Separating Characters in VAX-11 MACRO
Statements
Unary Operators
Binary Operators
Addressing Modes
Floating Point Short Literals
Index Mode Addressing
Summary of General Assembler Directives
.ENABLE and .DISABLE Symbolic Arguments
Condition Tests for Conditional Assembly
Directives
Operand Descriptors
Program Section Attributes
Default Program Section Attributes
.SHOW and .NOSHOW Symbolic Arguments
Summary of Macro Directives
Hexadecimal/ASCII Conversion
Assembler Directives
Special Characters Used in VAX-11 MACRO
Statements
Unary Operators
Binary Operators
Macro String Operators
Addressing Modes
Hexadecimal/Decimal Conversion

3-1
3-3
3-11

3-15
4-2

4-9
4-16
5-1
5-18
5-31
5-43
5-48

5-49
5-Sn
6-2

A-1
B-1
B-7

B-9
B-10
B-10
B-11

D-3

PREFACE

MANUAL OBJECTIVES
It includes the
This manual describes the VAX-11 MACRO language.
format and function of each feature of the language. The VAX-11 MACRO
User's Guide describes how to use VAX-11 MACRO.

INTENDED AUDIENCE
This manual is intended for all programmers writing VAX-11 MACRO
programs.
Programmers should be familiar with assembly language
programming, the VAX-11 instruction set, and the VAX/VMS operating
system before reading this manual.
The VAX-11 MACRO User's Guide provides a brief introduction to the
assembler and describes the commands necessary to use VAX-11 MACRO.
The VAX-11 Architecture Handbook describes the VAX-11 instruction set.
All programmers should read these manuals before using this language
reference manual.

STRUCTURE OF THIS DOCUMENT
This manual is organized into six chapters
follows:
introduces

the

and

appendixes,

the

VAX-11

MACRO

VAX-11

MACRO

source

•

Chapter 1
language.

•

Chapter 2 describes the format used
statements.

•

Chapter 3 describes the components of VAX-11 MACRO source
statements:
the character set;
numbers; symbols; local
labels; terms and expressions; unary and binary operators;
direct
assignment statements;
and the current location
counter.

•

Chapter 4 summarizes and gives examples
VAX-11 MACRO addressing modes.

•

Chapter 5 describes
directives.

the

features

four

VAX-11

vii

of
in

MACRO

the
general

use

the

assembler

•

Chapter 6 describes
expanding macros.

the

directives

used

defining

•

Appendix A lists the ASCII character set that can be
VAX-11 MACRO programs.

•

Appendix B summarizes the general assembler
and
macro
directives {in alphabetical order), special characters, unary
operators, binary operators, and addressing modes.

•

Appendix C lists alphabetically and by opcode the permanent
symbols {instruction set) defined for use with VAX-11 MACRO.

•

Appendix D gives rules for hexadecimal/decimal conversion.

used

and
in

ASSOCIATED DOCUMENTS

The following documents are relevant to VAX-11 MACRO programming:
•

VAX-11 Archi tectur~_!!~Ddl::>oo_~

•

VAX-11 MACRO User's Guide

•

VAX-11 Linker Reference Manual

•

VAX-11 Symbolic Debugger Reference Manual

For a complete list of all VAX-11 documents, including a brief
description of each, see the VAX-11 Information Directory and Index.

CONVENTIONS USED IN THIS DOCUMENT

The following conventions are observed in this manual, as in the other
VAX-11 documents:
Convention

Meaning

Uppercase words
and letters

Uppercase
words
and
letters,
examples, indicate that you should
word or letter exactly as shown.

Lowercase words
and letters

Lowercase words and letters, used in format
examples, indicate that you are to substitute
a word or value of your choice.
Square brackets indicate
item is optional.

that

the

used in
type the

enclosed

A horizontal ellipsis indicates that the
preceding item{s) can be repeated one or more
times.
A vertical ellipsis indicates that not all of
the statements in an example or figure are
shown.

viii

SUMMARY OF TECHNICAL CHANGES
This manual documents VAX-11 MACRO V2.0, as released with Release 2.0
of VAX/VMS.
This section summarizes the technical changes from the
last version, released with Release 1.5 of VAX/VMS.
Changes affecting directives:
There is a new data type, the octaword, which stores 128 bits
(lo
bytes)
of binary data.
The octaword storage directive is .OCTA. A
new block storage directive, .BLKO, reserves octawords for data.
A
new operand generation directive,
.REF16, generates an octaword
operand.
However, DIGITAL recommends using the opcode definition
directive, .OPDEF, instead of .REF;
there are new operand descriptors
for use with .OPDEF which describe octaword operators.
Two new floating-point directives provide additional flexibility and
capacity
for
floating-point numbers.
The
.G FLOATING directive
generates 64-bit data (quadwords) of which one bit- is the sign,
11
bits are exponent,
and 52 bits are
fraction.
The
.H FLOATING
directive generates 128-bit data (octawords) with one bit for-sign, 15
bits for exponent,
and 112 bits for fraction.
There are new block
storage directives,
.BLKG and
.BLKH, which
reserve
G floating
quadwords and H floating octawords,
respectively.
There- are new
operand descriptors for use with .OPDEF which describe G floating and
H floating operands.
(Note:
not all VAX-11 processors support the
G=floating and H_floating data types.)
To bring the formats of the floating-point data types and directives
into a consistent format, there are new alternate forms of the .FLOAT
directive - .F FLOATING - and the .DOUBLE directive .D FLOATING.
The terms F floating and n floating are used in this manual-to denote
single-precision and 64-bit-double precision data.
A new program section attribute, VEC, has been added for use with the
.PSECT
directive.
It
shows that a program section contains
information to be used in a privileged shareable image.
The new directives, attributes, and operand descriptors
listed
are all described under the directive names in Chapter 5.

above

New opcodes have been added to the VAX-11 instruction set to make use
of octaword, G floating, and H floating data.
These opcodes, and the
mnemonics that represent them in source code, are listed in Appendix

Miscellaneous changes:
•

User-define~

•

The ASCII string used with the ASCII operator (~A) may now be
up to 16 characters long, depending on the data type of the
operand.

•

Source statements used within macros may now
characters long.

symbols may now be up to 31 characters long.

1000

CHAPTER 1
INTRODUCTION

The VAX-11 MACRO programming language is an assembly language for
programming VAX-11 computers under the VAX/VMS operating system.
Source programs written in the VAX-11 MACRO programming language are
translated into object (or binary) code by the VAX-11 MACRO assembler,
which produces an object module and, optionally, a listing file.
These functions of the assembler are described in the VAX-11 MACRO
User's Guide. The features of the language itself are introduced in
this chapter.
VAX-11 MACRO source programs consist of a sequence of
source
statements. These source statements may be any of the following:
•

VAX-11 native-mode instructions

•

Direct assignment statements

•

Assembler directives

Instructions manipulate data.
They perform' such
functions
as
addition, data conversion, and transfer of control. Instructions are
usually followed in the source statement by operands, which can be any
kind of data needed for the operation of the instruction. The VAX-11
instruction set is summarized in Appendix C of this volume and is
described in detail in the VAX-11 Architecture Handbook.
Direct assignment statements equate symbols to values.
Assembler directives guide the assembly process and provide tools for
using
the
instructions.
There are two classes of assembler
directives: general assembler directives and macro directives.
General assembler directives can be used to perform the following:
•

Store data or reserve memory for data storage

•

Control the alignment in memory of parts of the program

•

Specify the methods of accessing the
which the program will be stored.

•

Specify the entry point of the
program

program

•

Specify the way in which

will be referenced

•

Specify that a part of the program is
under certain conditions

~ymbols

1-1

sections
or

memory

part

the

assembled

only

INTRODUCTION

•

Control the format and content of the listing file

•

Display informational messages

•

Control the assembler options that are used to
source program

•

Define new opcodes

Macro directives are used to define macros and
allow programmers to do the following:
sequences

repeat

•

Repeat identical or similar
throughout a program

•

Use string operators to manipulate and test
source statements

Use of macros and repeat blocks halps to
and to speed the debugging process.

1-2

minimize

interpret

the

blocks.

They

source
the

statements
contents

programmer

errors

CHAPTER 2
MACRO SOURCE STATEMENT FORMAT

A source program consists of a sequence of source statements, which
the assembler interprets and processes, one by one, generating object
code or performing a specific assembly-time process.
A source
statement can occupy one source line or can extend onto several source
lines. Each source line can be up to 132 characters long;
however,
no line should exceed 80 characters to ensure that the source line
fits (with its binary expansion) on one line in the listing file.
MACRO statements can consist of up to four fields:
•

Label field -- symbolically defines a location in a program

•

Operator field -- specifies the action to be performed by the
statement;
this field can be an instruction, an assembler
directive, or a macro call

•

Operand field -- contains the instruction operand(s) or
assembler directive argument(s) or the macro argument(s)

•

Comment field -- contains a comment that explains the
of
the statement;
this field does not affect
execution

the

meaning
program

The label field and the comment field are optional. The label field
ends with a colon (:) and the comment field starts with a semicolon
(;). The operand field must conform to the format of the instruction,
directive, or macro specified in the operator field.
Although statement fields can be separated by either a space or a tab
(see Table 3-2), formatting statements with the tab character is
recommended for consistency and clarity. By DIGITAL convention, tab
characters are used to separate the statement fields as follows:
Field

Begins in Column

Tab Characters to Reach Column

Label

Operator

Operand

Comment

For example:

LABT:
LAB2:

.TITLE
.ENTRY
CLRL
SUBL3
BRB

ROUTl
START,O
RO
#10,4(AP)R2
CONT

BEGINNING OF ROUTINE
CLEAR REGISTER
SUBTRACT 10
BRANCH TO ANOTHER ROUTINE
2-1

MACRO SOURCE STATEMENT FORMAT
A single statement can be continued on several lines by using a hyphen
(-) as the last nonblank character before the comment field or at the
end of line (when there is no comment). For example:
LABl:

MOVAL

VECTOR,RPB$L_IOVEC (R7)

W~BOO$AL

SAVE ADDRESS OF
BOOT DEVICE DRIVER.

VAX-11 MACRO treats the above statement as equivalent to the following
statement:
LABl:

MOVAL

W~BOO$AL_VECTOR,RPB$L_IOVEC(R7)

; SAVE BOOT DRIVER

A statement can be continued at any point. User-defined and permanent
symbol names;
however, should not be continued on two lines. If a
symbol name is continued and the first character on the second line is
a tab or a blank, the symbol name will be terminated at that
character.
(Section 3.3 describes symbols in detail.)
Note that when a statement occurs in a macro definition {see
6), the statement cannot contain more than 1000 characters.

Chapter

Blank lines, although legal, have no significance
program except that they terminate a continued line.

source

The following sections
detail.

2.1

describe

each

the

statement

fields

LABEL FIELD

A label is a user-defined symbol that identifies a location in the
program. The symbol is assigned a value equal to the location counter
at the location in the program section in which the label occurs (see
the VAX-11 MACRO User's Guide for information on program sections).
The user-defined symboY-name-can be up to 31 characters long and can
contain any alphanumeric character and the underline( ), dollar sign
($), and period (.) characters. Section 3.3 describes the rules for
forming user-defined symbol names in more detail.
If a statement contains a label, the label must be in the first
on the line.

field

A label is terminated by a colon (:) or a double colon (::). A single
colon indicates that the label is defined only for the current module
(an internal symbol). A double colon indicates that the label is
globally defined;
that is, the label can be referenced by other
object modules (see Section 3.3.2).
Once a label is defined, it cannot be redefined during the source
program.
If a label is defined more than once, VAX-11 MACRO displays
an error message when the label is defined and again when it is
referenced.
If a label extends past column 7, it should be placed on
itself so that the operator field can start in column 9.

2-2 .

line

MACRO SOURCE STATEMENT FORMAT

For example:
EVAL:
CLRL
ERROR IN ARG:
INCL
TEST:: MOVO
TESTl:
EXP:
DATA::

BRW
.BLKL
.BLKW

ROUTINE EVALUATES EXPRESSIONS
THE ARG-LIST CONTAINS AN ERROR
INCREMENT ERROR COUNT
THIS TESTS ROUTINE
REFERENCED EXTERNALLY
GO TO EXIT ROUTINE
TABLE STORES EXPECTED VALUES
DATA TABLE ACCESSED BY STORE
ROUTINE IN ALGO MODULE

RO
RO
EXP,Rl
EXIT ROU
50

The label field is also used for the symbol
statement (see Section 3.8).

direct

The operator field specifies the action to
statement.
This field can contain either
assembler directive, or a macro call.

be
an

performed by the
instruction, or an

2.2

assignment

OPERATOR FIELD

When the operator is an instruction, VAX-11 MACRO generates the binary
code for that instruction in the object module. The binary codes are
listed in Appendix C of this manual; the instruction set is described
in
the VAX-11 Architecture Handbook.
When the operator is a
directive, VAX-11 MACRO performs certain control actions or processing
operations during source program assembly; the assembler directives
are described in Chapters 5 and 6 of this manual. When the operator
is a macro call, VAX-11 MACRO expands the macro; macro calls are
described in Chapter 6.
Either a space or a tab character may terminate the operator
however, the tab is the recommended terminating character.

2.3

field;

OPERAND FIELD

The operand field can contain operands for instructions
for assembler directives or macro calls.

arguments

Operands for instructions identify the memory locations or the
registers that are used by the machine operation. These operands
specify the addressing mode for the instruction, as described in
Chapter
4 of this manual.
The operand field fo~ a specific
instruction must contain the number of operands required by that
instruction. See the VAX-11 Architecture Handbook for descriptions of
the instructions and their operands.
Arguments for a directive must meet the format requirements of the
directive. Chapters 5 and 6 describe the directives and the format of
their arguments.
Operands for a macro must meet the requirements specified in the macro
definition. See the description of the .MACRO directive in Chapter n.
If two or more operands are specified, they should be separated by
commas.
VAX-11 MACRO also allows a space or tab to be used as a
separator for arguments to any directive that does not accept
expressions (see Section 3.5).
However, a comma is required to
separate operands for instructions and for directives that accept
expressions as arguments.

2-3

MACRO SOURCE STATEMENT FORMAT
The semicolon that starts the comment field
terminates the operand
field.
If a line does not have a comment field, the operand field is
terminated by the end of the line.

2.4

COMMENT FIELD

The comment field contains text that explains the function of the
statement.
Every line of code should have a comment. Comments do not
affect assembly processing or program execution except for messages
displayed during assembly by the .ERROR, .PRINT, and .WARN directives
(see descriptions in Chapter 5).
The comment field must be preceded by a semicolon and is terminated by
the end of the line.
The comment field can contain any printable
ASCII character (see Appendix A).
If a comment does not fit on one line, it can be continued on the
next,
but the continuation must be preceded by another semicolon. A
comment can appear on a line by itself.
The text of a comment normally conveys the meaning rather than the
action of the statement.
The instruction MOVAL BUF PTR l,R7, for
instance, should have a comment such as "GET POINTER TO FIRST BUFFER"
not "MOVE ADDRESS OF BUF PTR l TO R7."
For example:
MOVAL

STRING_DES_l,RO

MOVZWL
MOVL

(RO) , Rl
4(RO) ,RO

GET ADDRESS OF STRING
DESCRIPTOR
GET LENGTH OF STRING
GET ADDRESS OF STRING

2-4

CHAPTER 3
THE COMPONENTS OF MACRO SOURCE STATEMENTS

MACRO
source
This chapter describes the components of VAX-11
statements.
These components consist of the character set; numbers;
unary and binary
symbols; local labels; terms and expressions;
operators;
direct assignment statements; and the current location
counter.

3.1

CHARACTER SET

The following
statements:

characters

can

used

VAX-11

MACRO

source

•

Both uppercase and lowercase letters (A through Z, a through
z)
are accepted. However, the assembler considers lowercase
letters equivalent to uppercase except when they appear in
ASCII strings.

•

The digits 0 through 9.

•

The special characters listed in Table 3-1.
Table 3-1
Special Characters Used in VAX-11 MACRO Statements

Character

Character Name

Function

Underline

Character in symbol names

Dollar sign

Charaqter in symbol names

Period

Character in symbol names,
current location counter, and
decimal point

Colon

Label terminator

EquaJ. sign

Direct assignment operator and
macro keyword argument terminator

Tab

Field terminator

Space

Field terminator

(continued on next line)

3-1

THE COMPONENTS OF MACRO SOURCE STATEMENTS
Table 3-1 (Cont.)
Special Characters Used in VAX-11 MACRO Statements
Character

Character Name

Function

Number sign

Immediate addressing mode
indicator

At sign

Def erred addressing mode
indicator and arithmetic shift
operator

Comma

Field, operand, and item
separator

Semicolon

Comment field indicator

Plus sign

Autoincrement addressing mode
indicator, unary plus operator,
and arithmetic addition operator

Minus sign or
hyphen

Autodecrement
addressing
mode
indicator, unary minus operator,
arithmetic subtraction operator,
and line continuation indicator

Asterisk

Arithmetic multiplication
operator

Slash

Arithmetic division operator

Ampersand

Logical AND operator

Exclamation
point

Logical inclusive OR operator

Backslash

Logical exclusive OR and numeric
conversion indicator in macro
arguments

Circumflex

Unary operators and macro
argument delimiter

[]

Square brackets

Index addressing mode and repeat
count indicators

()

Parentheses

Angle brackets

Argument or expression grouping
delimiters

Question mark

Created label indicator in macro
arguments

Apostrophe

Macro argument concatenation
indicator

Percent sign

Macro string operators

'--·-~----···-··------

----------------------------·---------

3-2

THE COMPONENTS OF MACRO SOURCE STATEMENTS

Table 3-2 defines the separating characters used in VAX-11 MACRO.
Table 3-2
Separating Characters in VAX-11 MACRO Statements
Character

3.2

Character Name

Usage

Space or tab

Separator between statement
fields. Spaces within
expressions (see Section 3. 5) are
ignored.

Comma

Separator between symbolic
arguments within the operand
field. Multiple expressions in
the operand field must be
separated by commas.

NUMBERS

Numbers can be integers, floating-point
strings.

numbers,

packed

decimal

Integers

3.2.1

Integers can be used in any expression including expressions in
operands and in direct assignment statements (Section 3.5 describes
expressions).

Format
snn
s

An optional sign:
plus sign (+)
for positive
default) or minus sign (-) for negative numbers.

numbers

A string of numeric characters that are
radix.

the

(the

nn
legal

for

current

VAX-11 MACRO interprets all integers in the source program as decimal
unless the number is preceded by a radix control operator (see Section
3.6.1).
Integers must be in the range of -2147483648 through 2147483647 for
signed data or in the range of 0 through 4294967295 for unsigned data.
Negative numbers must be preceded by a minus sign;
translates such numbers into 2's complement form.
numbers, the plus sign is optional.

3-3

VAX-11 MACRO
In positive

THE COMPONENTS OF MACRO SOURCE STATEMENTS
3.2.2

Floating-Point Numbers

A floating-point number can be used in the .F FLOATING (.FLOAT),
.D FLOATING,
(.DOUBLE)
.G FLOATING,
and .H FLOATING directives
(described in Chapter 5)
as an operand Tn a floating-point
instruction.
A floating-point number cannot be used in an expression
or with a unary or binary operator except the unary plus, unary minus,
and unary floating-point operator (~F). Sections 3.6 and 3.7 describe
unary and binary operators.

A floating-point number can be specified with or without an exponent.
Formats
Floating-point number without exponent:
snn
snn.nn
snn.
Floating-point number with exponent:
snnEsnn
snn.nnEsnn
snn.Esnn
s

An optional sign.
nn
A string of decimal digits in the range of O through 9.
The decimal point can appear anywhere to the right of the first digit.
However, note that a floating-point number cannot start with a decimal
point because VAX-11 MACRO will treat the number as a user-defined
symbol (see Section 3.3.2).
Floating-point
numbers
can
be
single-precision
(32-bit),
double-precision (64-bit), or extended-precision (128-bit) quantities.
The degree of precision is 7 digits for single-precision numbers, l~
digits for double-precision numbers, and 33 digits for extended
precision numbers.
The magnitude of a nonzero floating-point number cannot be smaller
than approximately 0.29E-38 or greater than approximately l.7E38.
Single-precision floating-point numbers can be rounded (by default) or
truncated.
The .ENABLE and .DISABLE directives (described in Chapter
5) control whether single-precision floating-point numbers are rounded
or truncated. Double-precision and extended-precision floating point
numbers are always rounded.
The VAX-11 Architecture Handbook
floating-point numbers.

describes

3-4

the

internal

format

THE COMPONENTS OF MACRO SOURCE STATEMENTS
3.2.3

Packed Decimal Strings

A packed decimal string can be used
(described in Chapter 5).

only

the

.PACKED

directive

Format
snn
s

An optional sign.
nn
A string of from 1 to 31 decimal digits in the range of 0 through
9.
A packed decimal string cannot have a decimal point or an exponent.
The VAX-11 Architecture Handbook
packed decimal strings.

3.3

describes

the

internal

format

SYMBOLS

Three types of symbols can be used in VAX-11 MACRO source
permanent symbols, user-defined symbols, and macro names.

3.3.1

programs:

Permanent Symbols

Permanent symbols consist of instruction mnemonics (see Appendix C),
VAX-11 MACRO directives
(see Chapters 5 and 6), and register names.
Instruction mnemonics and directives need not be defined before being
used in the operator field of a VAX-11 MACRO source statement.
Register names need not be defined before being used in the addressing
modes
(see Chapter 4). Register names cannot be redefined; that is,
no user-defined symbol can have one of the register names listed
below.
The 16 general registers of the VAX-11 processor can be expressed in a
source program only as follows:
Register
Name

Processor Register

General register 0

General register 1

General register 2

Rll

General register 11

Rl2 or
AP

General register 12 or argument pointer. If Rl2 is
used as an argument pointer, the name
AP
is
recommended;
if Rl2 is used as a general register,
the name Rl2 is recommended.
3-5

THE COMPONENTS OF MACRO SOURCE STATEMENTS
Register
Name

Processor Register

Frame pointer

Stack pointer

Program counter

3.3.2

User-defined Symbols and Macro Names

User-defined symbols can be used as labels or can be equated to
specific value by a direct assignment statement (see Section 3.8).
User-defined symbols also can be used in any expression

(see

Section

3.5).

The following rules govern the creation of user-defined symbols:
•

User-defined symbols can
be
composed
of
alphanumeric
characters, underlines (),dollar signs ($),and periods (.).
Any other character terminates the symbol.

•

The first character of a symbol must not be a number.

•

The symbol must be no more than 31
unique.

character~

long and must be

In addition, by DIGITAL convention:
•

The dollar sign ($) is reserved for names defined by DIGITAL.
This convention ensures that a user-defined name (which does
not have a dollar sign)
will
not
conflict
with
a
DIGITAL-defined name (which does have a dollar sign).

•

The period (.) should not be used in any global symbol name
(see Section 3.3.3) because other languages, such as FORTRAN,
do not allow periods in symbol names.

Macro names follow the same rules and conventions as user-defined
symbols (see the description of the .MACRO directive in Chapter 6 for
more information on macro names).
User-defined symbols and macro
names do not conflict;
that is, the same name can be used for a
user-defined symbol and a macro.
However, to avoid confusion,
user-defined symbols and macros should be given different names.

3.3.3

Determining Symbol Values

The value of a symbol depends on its use in the program. VAX-11 MACRO
uses a different method to determine the values of symbols in the
operator field than it uses to determine the values of symbols in the
operand field.
A symbol in the operator field can be either a permanent symbol or a
macro name.
VAX-11 MACRO searches for a symbol definition in the
following order:
•

Previously defined macro names

•

User-defined opcode (see the .OPDEF description in Chapter 5)

3-6

THE COMPONENTS OF MACRO SOURCE STATEMENTS

•

Permanent symbols (instructions and directives)

•

Macro libraries

This search order allows permanent symbols to be redefined as macro
names. If a symbol in the operator field is not defined as a macro or
a permanent symbol, the assembler displays an error message.
A symbol in the operand field must be either a user-defined symbol
a register name.

User-defined symbols can be either local (internal) symbols or global
(external) symbols.
Whether symbols are loc~l or global depends on
their use in the source program.
A local symbol can be referenced only in the module in which it is
defined.
If local symbols .with the same names are defined in
different modules, the symbols are completely independent.
A global
symbol's definition, however, can be referenced from any module in the
program.
Normally, VAX-11 MACRO treats all user-defined symbols as local when
they are defined.
However, a symbol definition can be explicitly
declared to be global by any one of the following three methods:
•

Use of the double colon (::) in defining a label (see

Section

2.1)

•

Use of the double equal sign
statement (see Section 3.8)

•

Use of the .GLOBAL, .ENTRY, or .WEAK directive (see Chapter 5)

(==)

direct

assignment

When a symbol is referenced within the module in which it is defined,
VAX-11 MACRO considers the reference an internal reference. When a
symbol is referenc~d within a module in which it is not defined,
VAX-11 MACRO considers the reference an external reference (that is,
the symbol is defined in another module). The .DISABLE directive can
be used to make references to symbols not defined in the current
module illegal. In this case, the .EXTERNAL directive must be used to
specify that the reference is an external reference. See Chapter 5
for descriptions of the .DISABLE and .EXTERNAL directives.

3.4

LOCAL LABELS

Local labels are used to identify addresses within a block
code.

source

user-defined

symbol

•

Local labels cannot be referenced outside the block of
code in which they appear.

source

•

Local labels can be reused in another block of source code.

Format

nn$
nn
A decimal integer in the range of 1 through 65535.
Local labels can be used in the same way
labels, but with the following differences:

3-7

THE COMPONENTS OF MACRO SOURCE STATEMENTS
•

Local labels do not appear in the symbol
cannot be accessed by the debugger.

tables

and,

•

Local labels cannot be used in .END (see Chapter 5).

thus,

By convention, local labels are positioned like statement labels:
left-justified in the source text. Although local labels can appear
in the program in any order, by convention, the local labels in any
block of source code should be in numeric order.
Local labels are useful as branch addresses when the address is used
only within the block.
Local labels can be used to distinguish
between addresses that are referenced only in a small block of code
and addresses that are referenced elsewhere in the module.
A
disadvantage of local labels is that their numeric names cannot
provide any indication of their purpose. Consequently, local labels
should not be used to label sequences of statements that are logically
unrelated;
user-defined symbols should be used instead.
DIGITAL recommends that users create local labels only in the range of
1$ to 29999$ because the assembler automatically creates local labels
in the range of 30000$ to 65535$ for
use
in macros
(see Section
6.1.6).
The local label block in which a local label is valid is delimited
the following statements:

•

A user-defined label

•

A .PSECT directive (see Chapter 5)

•

The .ENABLE and .DISABLE directives (see Chapter 5) which can
extend a local label block beyond user-defined labels and
.PSECT directives

A local label block is usually delimited by two user-defined labels.
However,
the
.ENABLE LOCAL BLOCK directive starts a local block that
is terminated only by one of-the following:
e

A second .ENABLE LOCAL BLOCK directive

A .DISABLE LOCAL BLOCK directive followed
label or a .PSECT directive

user-defined

Although local label blocks can extend from one program section to
another, DIGITAL recommends that local labels in one program section
not be referenced from another program section.
User-defined symbols
should be used instead.
Local labels can be preserved for future reference with the context of
the program section in which they are defined;
see the descriptions
of the .SAVE PSECT
[LOCAL BLOCK]
directive and the
.RESTORE PSECT
directive in-Chapter 5.
An example showing the use of local labels follows.

3-8

THE COMPONENTS OF MACRO SOURCE STATEMENTS
RPSUB:
10$:

MOVL
SUBL2
BGTR
ADDL2
MOVL
CLRL
CMPL
BGTR
SUBL
INCL
BRB
MOVL
BRW

AMOUNT,RO
DELTA,RO
10$
DELTA,RO
MAX,Rl
R2
RO,Rl
20$
INCR,RO
R2
10$
R2,COUNT
TEST

.ENABLE
POPR
ADDL3
BRB

LOCAL BLOCK
#AM<RO,Rl,R2>
RO,Rl,R3
10$

ENTR2:

SUBL2

R2,R3

10$:

SUBL2
BGTR
INCL
BRB

R2,R3
20$
RO
NEXT

20$:

DECL
RO
.DISABLE LOCAL BLOCK
CLRL
R4

COMP:
10$:

20$:

ENTRl:

3.5

STARTS LOCAL LABEL BLOCK
DEFINE LOCAL LABEL 10$
CONDITIONAL BRANCH TO LOCAL LABEL
EXECUTED WHEN RO NOT > 0
ENDS PREVIOUS LOCAL LABEL
BLOCK AND STARTS NEW ONE
DEFINE NEW LOCAL LABEL 10$
CONDITIONAL BRANCH TO LOCAL LABEL
EXECUTED WHEN RO NOT > Rl
I

•

UNCONDITIONAL BRANCH TO LOCAL LABEL
DEFINE LOCAL LABEL
UNCONDITIONAL BRANCH TO
USER-DEFINED LABEL
START LOCAL LABEL BLOCK
THAT WILL NOT BE TERMINATED
BY A USER-DEFINED LABEL
BRANCH TO LOCAL LABEL THAT IS AFTER
A USER-DEFINED LABEL
DOES NOT START A NEW
LOCAL LABEL BLOCK
DEFINE LOCAL LABEL
CONDITIONAL BRANCH TO LOCAL LABEL
EXECUTED WHEN R2 NOT > R3
UNCONDITIONAL BRANCH TO
USER-DEFINED LABEL
DEFINE LOCAL LABEL
DIRECTIVE FOLLOWED
BY USER-DEFINED LABEL TERMINATES
LOCAL LABEL BLOCK

TERMS AND EXPRESSIONS

A term can be any one of the following:
•

A number

•

A symbol

•

The current location counter {see Section 3.9)

•

A textual operator followed by text (see Section

3.~.2)

•

Any of the above preceded by a
3.6)

{see

unary

operator

Section

VAX-11 MACRO evaluates terms as longword
{4-byte)
values.
If an
undefined symbol
is used as a term, the linker determines the term's
value.
The current location counter (.) has the value of the location
counter at the start of the current operand.
Expressions are combinations of terms joined by binary operators
(see
Section 3.7) and evaluated as longword (4-byte) values. VAX-11 MACRO
evaluates expressions from left to right with no operator precedence
rules.
However,
angle brackets (<>) can be used to change the order
of evaluation. Any part of an expression that is enclosed in angle
brackets is first evaluated to a single value, which is then used in
evaluating the complete expression.
For example,
the expressions
A*B+C and A*<B+C> are different.
Angle brackets can also be used to
apply a unary operator to an entire expression, such as -<A+B>.
Note that unary operators are considered part of a term;
thus, VAX-11
MACRO performs the aGtion
indicated by a unary operator before it
performs the action indicated by any binary operator.
3-9

THE COMPONENTS OF MACRO SOURCE STATEMENTS
Expressions fall into three categories:
external (global).
•

relocatable,

absolute,

and

An expression is relocatable if its value is fixed relative to
the start of the program section in which it appears. The
current location counter is relocatable in a relocatable
program section.

expression is absolute if its value is an assembly-time
• An
constant.
An expression whose terms are all numbers is
absolute. An expression that consists of a relocatable term
minus another relocatable term from the same program section
an
is absolute, because such an expression reduces to
assembly-time constant.
•

An expression is external if it contains one or
that are not defined in the current module.

Any type of expression can be used in most macro
restrictions are placed on expressions used in:

symbols

statements,

•

.ALIGN alignment directive

•

.BLKx storage allocation directives

•

.IF and .!IF conditional assembly block directives

•

.REPEAT repeat block directive

•

.OPDEF opcode definition directive

•

.ENTRY entry point directive

.BYTE, .LONG, .WORD, .SIGNED_BYTE, and .SIGNED WORD
repetition factors

•

Direct assignment statements (see Section 3.8)

but

directive

See Chapter 5 for descriptions of the directives listed above, except
.REPEAT which is described in Chapter n. Expressions used in these
directives and in direct assignment statements can only contain
symbols that have been previously defined in the current module. They
cannot contain either external symbols or symbols defined later in the
current module. In addition, the expressions in these directives must
be absolute. Expressions in direct assignment statements can be
relocatable.
An example showing the use of expressions follows.
A = 2*100
.BLKB
LAB:
HALF

.BLKW
A
LAB+<A/2>

LAB2:

.BLKB

LAB2-LAB

.WORD

LAB3-LAB2

.WORD

TST+LAB+2

LAB3:

2*100 IS AN ABSOLUTE EXPRESSION
A+SO IS AN ABSOLUTE EXPRESSION AND
CONTAINS NO UNDEFINED SYMBOLS
LAB IS RELOCATABLE
LAB+<A/2> IS A RELOCATABLE
EXPRESSION AND CONTAINS NO
UNDEFINED SYMBOLS
LAB2-LAB IS AN ABSOLUTE EXPRESSION
AND CONTAINS NO UNDEFINED SYMBOLS
LAB3-LAB2 IS AN ABSOLUTE EXPRESSIO
BUT CONTAINS THE SYMBOL LAB3
THAT IS DEFINED LATER IN THIS MODU
TST+LAB+2 IS AN EXTERNAL EXPRESSIO
BECAUSE TST IS AN EXTER~AL SYMBOL

A+SO

3-10

THE COMPONENTS OF MACRO SOURCE STATEMENTS

3.6

UNARY OPERATORS

A unary operator modifies a term or an expression, and indicates an
action to be performed on that term or expression. Expressions
modified by unary operators must be enclosed in angle brackets. Unary
operators can be used to indicate whether a term or expression is
positive or negatlve (if unary plus or minus is not specified, the
value is assumed to be plus, by default).
In addition, unary
operators perform radix conversion, textual conversion (including
ASCII conversion), and numeric control operations, as described in
Sections 3.6.1 through 3.6.3.
Table 3-3 summarizes the
unary
operators.
Table 3-3
Unary Operators
Unary
Operator

Operator Name

Example

Operation

Plus sign

Results in the positive
value of A

Minus sign

-A

Results in the negative
(2's complement) value
of A

Binary

"BllOOOlll

Specifies that 11000111
is a binary number

Decimal

"'0127

Specifies that 127 is a
decimal number

Octal

"034

Specifies that 34 is an
octal number

Hexadecimal

"XFCF9

Specifies that FCF9 is
a hexadecimal number

ASCII

"A/ABC/

Produces an ASCII
string; the characters
between the matching
delimiters are
converted to ASCII
representation

#"M<R3,R4,R5>

Specifies the registers
R3, R4, and R5 in the
register mask

Floating point

"F3.0

Specifies that 3.0 is a
floating-point number

Complement

"C24

Produces the l's
complement value of 24
(decimal)

3-11

THE COMPONENTS OF MACRO SOURCE STATEMENTS

More than one unary operator can be applied to a single term or to
expression enclosed in angle brackets. For example:

-+-A
This construct is equivalent to:
-<+<-A»

3.6.1

Radix Control Operators

VAX-11 MACRO accepts terms or expressions in four different radixes:
binary, decimal, octal, and hexadecimal.
The default radix is
decimal. Expressions modified by radix control operators must be
enclosed in angle brackets.
Formats

""Bnn
"'Dnn
"'onn

"'Xnn
nn

A string of characters that are legal in the specified
The legal characters for each radix are listed below.
Format

Radix Name

Legal Characters

"'Bnn

Binary

0 and 1

"'Dnn

Decimal

0 through 9

"'Onn

Octal

0 through 7

""Xnn

Hexadecimal

0 through 9 and A through F

radix.

Radix control operators can be included in the source program anywhere
a numeric value is legal. A radix control operator affects only the
term or expression immediately following it, causing that term or
expression to be evaluated in the specified radix.
For example:
.WORD
.WORD
.WORD
.WORD
.LONG

BINARY RADIX
DECIMAL RADIX (DEFAULT)
OCTAL RADIX
13 IS IN OCTAL RADIX
ALL NUMBERS IN EXPRESSION
ARE IN HEXADECIMAL RADIX

""BOOOOllOl

""Dl23
"'047

<A+""Ol3>
""X<FlC3+FFFFF-20>

The circumflex cannot be separated from the B, D, O, or X that follows
it, but the entire radix control operator can be separated by spaces
and tabs from the term or expression that is to be evaluated in that
radix.
The decimal operator, the default, is needed only within an expression
that has another radix control operator. In the following example,
the 16 would be interpreted as an octal number if the ""D operator did
not precede it:
.LONG

""0<10000 + 100 + ""Dl6>

3-12

THE COMPONENTS OF MACRO SOURCE STATEMENTS
3.6.2

Textual Operators

The textual operators are the ASCII operator
mask operator (AM).

(AA)

and

the

3.6.2.l ASCII Operator - The ASCII operator converts a string of
printable characters to their 8-bit ASCII values and stores them one
character to a byte. The string of characters must be enclosed in a
pair of matching delimiters.
The delimiters can be any printable character except the space, tab,
or semicolon (;).
Although alphanumeric characters can be used as
delimiters, nonalphanumeric characters should be used to
avoid
confusion.
Format
AAstring
string
A delimited ASCII string from 1 through 16 characters long.
The delimited ASCII string must not be larger than the data type of
the operand. For example, if the AA operator occurs in an operand in
a MOVW instruction (the data type is a word), the delimited string
cannot be more than two characters.
For example:
MOVL

MOVES CHARACTERS A,B,C,D
INTO RO RIGHT JUSTIFIED WITH
"A" IN LOW-ORDER BYTE AND "D"
IN HIGH-ORDER BYTE
COMPARES X AND Y AS ASCII
CHARACTERS WITH CONTENTS OF LOW
ORDER 2 BYTES OF RO
GENERATES 8 BYTES OF ASCII DATA
MOVE ASCII CHARACTERS AB INTO
RO; "A" IN LOW-ORDER BYTE; "B"
IN NEXT; AND ZERO THE 2 HIGHORDER BYTES

CMPW
.QUAD
MOVL

AA%1234/678%
#AA/AB/,RO

3.6.2.2 Register Mask Operator - The register mask operator converts
a register name or a list of register names enclosed in angle brackets
into a 1- or 2-byte register mask. The register mask is used by the
PUSHR and POPR instructions and the .ENTRY and .MASK directives (see
Chapter 5).
Formats
AM reg-name
AM< reg-name-list>
reg-name
One of the register names or the DV or IV arithmetic trap
specifiers.
reg-name-list
A list of register names and/or the DV and
enable specifiers, separated by commas.

3-13

arithmetic

enable

trap

THE COMPONENTS OF MACRO SOURCE STATEMENTS

The register mask operator sets a bit in the register mask for every
register name or arithmetic trap enable specified in the list. The
bits corresponding to each register name and arithmetic trap enable
specifier are listed below.
Register Name

Arithmetic Trap
Enable

Bits

RO through Rll

0 through 11 (respectively)

Rl2 or AP

When the register mask operator is used in a POPR or
PUSHR
instruction, RO through Rll, Rl2 or AP, FP, and SP can be specified.
The PC register name and the IV and DV arithmetic trap enable
specifiers cannot be specified.
When the register mask operator is used in the .ENTRY or .MASK
directives, R2 through Rll and the IV and DV arithmetic trap enable
specifiers can be specified. However, RO, Rl, FP, SP, and PC cannot
be specified.
IV sets the integer overflow trap, and DV sets the
decimal string overflow trap.
See the VAX-11 Architecture Handbook for more information on
masks and arithmetic trap enable specifiers.

For example:

3.6.3

.ENTRY

RT1,AM<R3,R4,R5,R6,IV>

PUSHR

#AM<RO,Rl,R2,R3>

POPR

#AM<RO,Rl,R2,R3>

SAVE REGISTERS R3,R4
RS, AND R6 AND SET THE
INTEGER OVERFLOW TRAP
SAVE REGISTERS RO,Rl,
R2, AND R3
RESTORE RO,Rl,R2, AND R3

Numeric Control Operators

The numeric control operators are the floating-point operator (AF) and
the complement operator (AC).

3.6.3.1 Floating-Point Operator - The floating-point operator accepts
a floating-point number and converts it to its internal representation
(a 4-byte value). This value can be used in any expression.
VAX-11
MACRO does not perform floating-point expression evaluation.
Format
~Fliteral

literal
A floating-point number (see Section 3.2.2).
The floating-point operator is
useful
because
it
allows
floating-point number in an instruction that accepts integers.

3-14

THE COMPONENTS OF MACRO SOURCE STATEMENTS

For example:
MOVL

#"'F3.7,RO

MOVF

#3.7,RO

NOTE THE RECOMMENDED INSTRUCTION
TO MOVE THIS FLOATING-POINT NUMBER
IS THE MOVF INSTRUCTION

3.6.3.2 Complement Operator - The complement
l's complement of the specified value.

operator

produces

the

Format

""cterm
term
Any term or expression. If an expression is specified,
be enclosed in angle brackets.

must

VAX-11 MACRO evaluates the term or expression as a 4-byte value before
complementing it.
For example:
.LONG
.LONG

3.7

""c""XFF
""c25

PRODUCES FFFFFFOO (HEX)
PRODUCES COMPLEMENT OF
25 (DEC) WHICH IS
FFFFFFE6 (HEX)

BINARY OPERATORS

In contrast to unary operators, binary operators specify actions to be
performed on two terms or expressions. Expressions must be enclosed
in angle brackets. Table 3-4 summarizes the binary operators.
Table 3-4
Binary Operators
Binary
Operator

Operator Name

Example

Operation

Plus sign

A+B

Addition

Minus sign

A-B

Subtraction

Asterisk

A*B

Multiplication

Slash

A/B

Division

At sign

A@B

Arithmetic shift

Ampersand

A&B

Logical AND

Exclamation p oint

A!B

Logical inclusive OR

Backslash

A\B

Logical exclusive OR

3-15

THE COMPONENTS OF MACRO SOURCE STATEMENTS
All binary operators have equal priority. Terms or expressions can be
grouped for evaluation by enclosing them in angle brackets. The
enclosed terms and expressions are then evaluated first, and remaining
operations are performed from left to right. For example:
.LONG
.LONG

1+2*3
1+<2*3>

; EQUALS 9
; EQUALS 7

Note that a 4-byte result is returned from all binary operations.
If
a 1-byte or 2-byte operand is used, the result is the low-order
byte(s) of the 4-byte result. VAX-11 MACRO displays an error message
if the truncation causes a loss of significance.
The· following sections describe the arithmetic shift, logical AND,
logical inclusive OR, and logical exclusive OR operators in more
detail.

3.7.1

Arithmetic Shift Operator

The arithmetic shift operator (@) is used to perform left and right
arithmetic shift of arithmetic quantities.
The first argument is
shifted left or right the number of bit positions specified by the
second argument.
If the second argument is positive, the first
argument is shifted left; if the second argument is negative, the
first argument is shifted right. When the first argument is shifted
left, the low-order bits are set to O; and when the first argument is
shifted right, the high-order bits are set to the value of the
original high-order bit (the sign bit).
For example:

.LONG
.LONG
MOVL

AB101@4
1@2
#<AB1100000@-5>,RO

YIELDS 1010000 (BINARY)
YIELDS 100 (BINARY)
YIELDS 11 (BINARY)

.LONG
.LONG

l@A
AX1234@-A

YIELDS 10000 (BINARY)
YIELDS 123(HEX)

3.7.2

Logical AND Operator

The logical AND operator (&) takes the logical AND of two operands.
For example:
A
B

AB1010
ABllOO
.LONG

A&B

YIELDS 1000 (BINARY)

3-16

THE COMPONENTS OF MACRO SOURCE STATEMENTS

Logical Inclusive OR Operator

3.7.3

The logical inclusive OR operator (!) takes the logical
of two operands.

inclusive

For example:
A

~81010

~81100

.LONG

YIELDS 1110 (BINARY)

A!B

Logical Exclusive OR Operator

3.7.4

The logical exclusive OR operator (\) takes the logical
of two arguments.

exclusive

For example:
A
B

~81010
~81100

.LONG

3.8

A\B

YIELDS 0110 (BINARY)

DIRECT ASSIGNMENT STATEMENTS

A direct assignment statement equates a symbol to a specific value.
Unlike a symbol that is used as a label, a symbol defined with a
direct assignment statement can be redefined as many times as desired.

Formats
symbol=expression
symbol==expression
symbol
A user-defined symbol.
expression
An expression that does not contain any
Section 3.5).

undefined

symbols

(see

The format with a single equal sign {=) defines a local symbol and the
format with a double equal sign {==) defines a global symbol. See
Section 3.3.3 for more information about local and global symbols.
The following
statements:

three

syntactic

rules

apply

direct

assignment

•

An equal sign {=) or double equal sign {==) must separate the
symbol from the expression defining the symbol's value.
Spaces preceding and/or following the direct
assignment
operators have no significance in the resulting value.

•

Only one symbol can be defined in a single
statement.

•

A direct assignment
comment field.

statement

3-17

can

direct

followed

assignment
only

THE COMPONENTS OF MACRO SOURCE STATEMENTS
In addition, by DIGITAL convention, the symbol in a direct
statement is placed in the label field.

assignment

For example:
A

= 1

A@5

THE SYMBOL 'A' IS GLOBALLY
EQUATED TO THE VALUE 1
THE SYMBOL 'B' IS EQUATED
TO 1@5 OR 20(HEX)
THE SYMBOL 'C' IS EQUATED
TO 1270(DEC)
THE SYMBOL 'D' IS EQUATED
TO lO(HEX)

c = 127*10
D = "'XlOO/""XlO

3.9

CURRENT LOCATION COUNTER

The period (.), the symbol for the current location counter, always
has the value of the address of the current byte. VAX-11 MACRO sets
the current location counter to 0 at the beginning of the assembly and
at the beginning of each new program section.
Every VAX-11 MACRO source statement that allocates memory in the
object module increments the value of the current location counter by
the number of bytes allocated. For example, the directive .LONG 0
increments the current location counter by 4. However, a direct
assignment statement, except the special form described below, does
not increase the current location counter because no memory is
allocated.
The current location counter can be explicitly set by a special form
of the direct assignment statement.
The location counter can be
either incremented or decremented. Explicitly. setting the location
counter is often useful when defining data structures. Data storage
areas should not be reserved by explicitly setting the location
counter; the .BLKx directives should be used instead (see Chapter 5).
Format
.=expression
expression
An expression that does not contain any
Section 3.5).

undefined

symbols

(see

In a relocatable program section, the expression must be relocatable;
that is, the expression must be relative to an address in the current
program section. It can be relative to the current location counter.
For example:
MOVES LOCATION COUNTER
FORWARD

= .+40

When a program section previously defined in the current module is
continued, the current location counter is set to the last value of
the current location counter in that program section.
When the current location counter is used in the operand field of an
instruction, the current location counter has the value of the address
of that operand--it does not have the value of the address of the
beginning of the instruction. For this reason, the current location
counter is not normally used as a part of the operand specifiar.

3-18

CHAPTER 4
ADDRESSING MODES

This chapter summarizes the VAX-11 addressing modes and contains
examples of VAX-11 MACRO statements that use these addressing modes.
The VAX-11 Architecture Handbook describes the addressing modes in
detail.
There are four types of addressing modes:
•

General Register

•

Program Counter

•

Index

•

Branch

Although index mode is a general register mode,
it is considered a
separate type of mode because it can be used only in combination with
another type of mode.
Table 4-1 summarizes the addressing modes.

4.1

GENERAL REGISTER MODES

The general register modes use registers RO through Rl2, AP {the
as Rl2)' FP, and SP.
There are eight general register modes:
•

•

Autoincrement

•

Autoincrement Def erred

•

Autodecrement

•

Displacement

•

Displacement Deferred

•

Literal

4-1

same

ADDRESSING MODES
Table 4-1

Addressing Modes
---

Type

Addressing
Mode

Format*
--+------ ______

Hexadecimal
Value

Description

Indexable?

-----·----·----------------·

~,,

----i

(Rn)

Yes

Auto increment

(Rn)+

Register contains the address of the
operand; the processor
increments the register contents
by the size of the operand data
type

Yes

Auto increment
Def erred

@(Rn)+

Yes

Autodecrement

-(Rn)

The processor decrements the
register contents by the size
of the operand data type; the
register then contains the
address of the operand

Yes

Displacement

dis(Rn)
B"dis(Rn)
W"dis(Rn)
L"dis(Rn)

The sum of the contents of the
register and the displacement is
the address of the operand; B",
w",and L" indicate byte, word,
and longword displacement,
respectively

Yes

Displacement
Deferred

@dis(Rn)
@B"dis(Rn)
@W"dis(Rn)
@L"dis(Rn)

The sum of the contents of the
register and the displacement is
the address of the operand
address; B", w", and L"
indicate byte, word, and
longword displacement,
respectively

Yes

B
D
F

General
Register
(Cont.)

Literal

tliteral
S"tliteral

The literal specified is the
the operand; the literal is
stored as a short literal

0-3

Program
Counter

Relative

General
Register

address
B"address
W"address
L"address

Relative
Deferred

@address
@B"address
@W"address
@L"address

B
D
F

Absolute

@taddress

Immediate

tliteral
I"tli teral

G"address

General

The address specified is the Yes
address of the operandi the
address specified is stored as a
d~splacement from PC;
B", W",
and L" indicate byte, word, and
longword displacement,
respectively
The address specified is the address
of the operand address; the address
specified is stored as a
displacement from PC; B", W",
and L" indicate byte, word, and
longword displacement,
respectively

Yes

The address specified is the address
of the operand; the address
specified is stored as an
absolute virtual address (not as
a displacement)

Yes

The literal specified is the
operand; the literal is stored
as a byte, word, longword, or
quadword

The address specified is the
address of the operand;[ if the
address is defined as
relocatable, the linker stores
the address as a displacement
from PC; if the address is
defined as an absolute virtual
address, the linker stores the
address as an absolute value

Yes

---·---------- L..-.

(continued on next page)

4-2

ADDRESSING MODES
Table 4-1 (Cont.)
Addressing Modes
_,...__,,

Type

Addressing
Mode

Format*

Hexadecimal
Value

Indexable?

Description

Index

base-mode [Rx]

The base-mode specifies the base
address and the register
specifies the index; the sum of
the base address and the product
of the contents of Rx and the
size of the operand data type is
the address of the operand;
base-mode can be any addressing
mode except register, immediate,
literal, index, or branch

Branch

address

The address specified is the
operand; this address is stored
as a displacement to PC; branch
mode can only be used with the
branch instructions

. ---'-···-··

____

-·--·~·-· ,,.-;~~ -

·--··

Key:

Rn
Any general register RO through Rl2. Note that the AP, FP, or SP
register can be used in place of Rn.

Rx
Any general register RO through Rl2. Note that the AP, FP, or SP
register can be used in place of Rx. Rx cannot be the same as the Rn
specified in the base-mode for certain base modes(see Section4.3).

dis
An expression specifying a displacement.

address
An expression specifying an address.

literal
An expression, an integer constant, or a floating-point constant.

4-3

ADDRESSING MODES
4.1.1

In register mode, the operand is the
register, except in the following cases:

contents

the

specified

•

For quadword, D floating, G floating or variable-bit field
operands,
the- operand
Ts the contents of register n
concatenated with the contents of register n+l.

•

For octaword and H floating operands,
contents of register n concatenated
registers n+l, n+2, and n+3.

the operand is the
with the contents of

In each of these cases, the least significant bytes of the operand are
in register n and the most significant bytes are in the highest
register used, either n+l or n+3.
The results of the operation are unpredictable if PC is used in
register mode or if the use of a large data type extends the operand
into the PC.
Formats
Rn
AP
FP
SP
n

A number in the range of 0 through 12.
Example
CLRB
CLRQ
TSTW
INCL

4.1.2

RO
Rl
RlO
R4

CLEAR LOWEST BYTE OF RO
CLEAR Rl AND R2
TEST LOWER WORD OF RlO
ADD 1 TO R4

In register deferred mode, the register contains the address of the
operand.
Register deferred mode can be used with index mode (see
Section 4.3).
Formats
(Rn)
(AP)
(FP)
(SP)
n

A number in the range of 0 through 12.
Example

10$:

MOVAL
CMPL
BEQL
CLRL
MOVL
MOVZBL

LDATA,R3
(R3) ,RO
10$
(R3)
(SP) ,Rl
(AP) ,R4

MOVE ADDRESS OF LDATA TO R3
COMPARE VALUE AT LDATA TO RO
IF THEY ARE THE SAME, IGNORE
CLEAR LONGWORD AT LDATA
COPY TOP ITEM OF STACK INTO Rl
GET NUMBER OF ARGUMENTS IN CALL

4-4

ADDRESSING MODES
Autoincrement Mode

4.1.3

In autoincrement mode,
the register contains the address of the
operand.
After evaluating the operand address contained in the
register, -the processor increments that address by the size of the
operand data type.
The processor
increments the contents of the
register by 1, 2, 4, 8, or 16 for a byte, word, longword, quadword, or
octaword operand, respectively.
Autoincrement mode can be used with index mode (see Section 4.3),
but
the
index register cannot be the same as the register specified in
autoincrement mode.

Formats
(Rn)+
(AP)+
(FP)+
(SP)+
n

A number in the range of 0 through 12.

Example
MOVAL
CLRQ
CLRL
MOVAB
INCB
INCB
XORL3

TABLE,Rl
(Rl)+
(Rl)+

GET ADDRESS OF TABLE
CLEAR FIRST AND SECOND LONGWORDS
AND THIRD LONGWORD IN TABLE
LEAVE Rl POINTING TO TABLE +12
BYTARR,R2
GET ADDRESS OF BYTARR
(R2)+
INCREMENT FIRST BYTE OF BYTARR
AND SECOND
(R2)+
(R3)+,(R4)+,(RS)+ ; EXCLUSIVE-OR THE TWO LONGWORDS
WHOSE ADDRESSES ARE STORED IN
R3 AND R4 AND STORE RESULT IN
ADDRESS CONTAINED IN RS, THEN
ADD 4 TO R3, R4, AND RS

Autoincrement Deferred Mode

4.1.4

In autoincrement deferred mode, the register contains an address that
is the address of the operand address (a pointer to the operand).
After evaluating the operand address,
the processor
increments the
contents of the register by 4 (the size in bytes of an address).
Autoincrement deferred mode can be used with index mode
(see Section
4.3),
but the index register cannot be the same as the register
specified in autoincrement deferred mode.

Formats
@(Rn)+
@(AP)+
@(FP)+
@(SP)+
n

A number in the range of O through 12.

4-5

ADDRESSING MODES
Example
MOVAL
CLRQ

PNTLIS,R2
@(R2)+

CLRB

@(R2)+

MOVL

RlO,@(RO)+

GET ADDRESS OF POINTER LIST
CLEAR QUADWORD POINTED TO BY
FIRST ABSOLUTE ADDRESS IN PNTLIS
THEN ADD 4 TO R2
CLEAR BYTE POINTED TO BY SECOND
ABSOLUTE ADDRESS IN PNTLIS
THEN ADD 4 TO R2
MOVE RlO TO LOCATION WHOSE ADDRESS
IS POINTED TO BY RO; THEN ADD 4
TO RO

Autodecrement Mode

4.1.5

In autodecrement mode, the processor decrements the contents of the
register by the size of the operand data type;
then the register
contains the address of the operand.
The processor decrements the
register by 1, 2, 4, 8, or 16 for byte, word, longword, quadword, or
octaword operands, respectively.
Autodecrement mode can be used with index mode (see Section 4.3),
but
the
index register cannot
be the same as the register specified in
autodecrement mode.

Formats
- (Rn)

-(AP)
-(FP)
- (SP)
n

A number in the range of 0 through 12.

Example

4.1.6

CLRO

-(Rl)

MOVZBL

R3,-(SP)

CMPB

Rl,-(RO)

SUBTRACT 8 FROM Rl AND ZERO THE
OCTAWORD WHOSE ADDRESS IS THEN
IN Rl
PUSH THE ZERO-EXTENDED LOW BYTE
OF R3 ONTO THE STACK AS A LONGWORD
ONTO THE STACK
SUBTRACT 1 FROM RO AND COMPARE LOW
BYTE OF Rl WITH BYTE WHOSE ADDRESS
IS NOW IN RO

Displacement Mode

In displacement mode, the sum of the contents of the register and the
displacement
(sign extended to a
longword)
is the address of the
operand.
Displacement mode can be used with index mode

4-6

(see Section 4.3).

ADDRESSING MODES
Formats
dis (Rn)
dis(AP)
dis(FP)
dis(SP)
n

A number in the range of 0 through 12.
dis
An expression specifying a displacement; the expression can be
preceded by one of the following displacement length specifiers,
which indicate the number of bytes needed to
store
the
displacement.

Displacement
Length Specifier
B"'

w"'

L ....

Meaning
Displacement requires 1 byte
Displacement requires 1 word (2 bytes)
Displacement requires 1 longword (4 bytes)

If no displacement length specified precedes the expression and
the value of the expression is known, the assembler chooses the
smallest number of bytes
(1, 2, or 4) needed to store the
displacement. If no length specifier precedes the expression and
the value of the expression is unknown, the assembler reserves 1
word
(2
bytes) for the displacement.
Note that if the
displacement is either relocatable or defined later in the source
program, the assembler considers it unknown.
If the actual
displacement does not fit in the memory reserved, the linker
displays an error message.

Example
MOVAB
MOVB
MOVB
CLRW

MOVL
TSTB

MOVAB

KEYWORDS,R3
B"'IO(R3) ,R4

GET ADDRESS OF KEYWORDS
GET BYTE WHOSE ADDRESS IS
IO PLUS ADDRESS OF KEYWORDS
i THE DISPLACEMENT IS STORED AS A BYTE
B"'ACCOUNT(R3) ,RS; GET BYTE WHOSE ADDRESS IS ACCOUNT
PLUS ADDRESS OF KEYWORDS
THE DISPLACEMENT IS STORED AS A BYTE
L"'STA (Rl)
CLEAR WORD WHOSE ADDRESS
IS STA PLUS CONTENTS OF Rl
THE DISPLACEMENT IS STORED
AS A LONGWORD
MOVE RO TO ADDRESS THAT IS -2
R0,-2(R2)
PLUS THE CONTENTS OF R2
THE DISPLACEMENT IS STORED AS A BYTE
TEST THE BYTE WHOSE ADDRESS
EXTRN(R3)
IS EXTRN PLUS THE
ADDRESS OF KEYWORDS
THE DISPLACEMENT IS STORED AS A WORD
SINCE EXTRN IS UNDEFINED
2(RS),RO
MOVE <CONTENTS OF RS> + 2
TO RO

Note
If the value of the displacement is O and no displacement length
is specified, the assembler uses register deferred mode rather
than displacement mode.

4-7

ADDRESSING MODES
4.1.7

Displacement Deferred Mode

In displacement deferred mode, the sum of the contents of the register
and the displacement (sign extended to a longword) is the address of
the operand address (a pointer to the operand).
Displacement deferred mode can be used with index

mode

(see

Section

4. 3) •

Formats
@dis(Rn)
@dis(AP)
@dis(FP)
@dis(SP)
n

A number in the range of 0 through 12.
dis
An expression specifying a displacement;
the expression can be
preceded by one of the following displacement length specifiers,
which indicate the number of bytes needed to
store
the
displacement.

Displacement
Length Specifier
B"'

w"'
L ...

Meaning
Displacement requires 1 byte
Displacement requires 1 word (2 bytes)
Displacement requires 1 longword (4 bytes)

If no displacement length specifier precedes the expression and
the value of the expression is known, the assembler chooses the
smallest number of bytes
(1, 2, or 4) needed to store the
displacement.
If no length specifier precedes the expression and
the value of the expression is unknown, the assembler reserves 1
word
(2
bytes)
for the displacement.
Note that
if the
displacement is either relocatable or defined later in the source
program,
the assembler considers it unknown.
If the actual
displacement does not fit in the memory reserved,
the linker
displays an error message.

Example
MOVAL
CLRL

MOVL

CLRW

ARRPOINT,R6
@16(R6)

GET ADDRESS OF ARRAY OF POINTERS
CLEAR LONGWORD POINTED TO BY
LONGWORD WHOSE ADDRESS IS 16
PLUS THE ADDRESS OF ARRPOINT
; THE DISPLACEMENT IS STORED AS A BYTE
@B"'OFFS(R6),@RSOFF(R6) ; MOVE THE LONGWORD POINTED TO
BY LONGWORD WHOSE ADDRESS IS
OFFS PLUS THE ADDRESS OF ARRPOINT
TO THE ADDRESS POINTED TO BY
LONGWORD WHOSE ADDRESS IS
RSOFFS PLUS THE ADDRESS OF ARRPOINT
THE FIRST DISPLACEMENT IS STORED AS A BYTE
THE SECOND DISPLACEMENT IS STORED AS A WOF
@84(R2)
CLEAR THE WORD THAT IS POINTED
TO BY LONGWORD AT 84 PLUS THE
CONTENTS OF R2--THE ASSEMBLER USES
BYTE DISPLACEMENT AUTOMATICALLY

4-8

ADDRESSING MODES
Literal Mode

4.1.8

In literal mode, the value of the literal is stored in the
mode byte itself.

addressing

Formats
#literal
S""#literal
literal
An expression, an integer constant, or a floating-point constant.
The literal must fit
in the short literal form.
That is,
integers must be in the range of O through 63 and floating-point
constants must be one of the· 64 values listed in Table 4-2.
Floating-point short literals are stored with a 3-bit exponent
and a 3-bit fraction.
Table 4-2 also shows the value of the
exponent and the fraction
for
each literal.
See the VAX-11
Architecture Handbook for
information on the format of short
literals.
Table 4-2
Floating Point Short Literals

0
1
2
3
4
5
6
7

0.5
1.0
2.0
4.0
8.0
16.0
32.0
64.0

0.5625
1.125
2.25
4.5
9.0
18.0
3fl.O
72.0

0.625
1. 25
2.5
5.0
10.0
20.0
40.0
80.0

0.6875
1.37
2.75
5.5
11.0
22.0
44.0
88.0

0.75
1.5
3.0

0.8125
l .fi25
3.25

0.875
1. 75
3.5
7.0
14.0
28.0
56.0
112.0

0.9375
1.875
3.75
7.5
15.0
30.0

fi .o

12.0
24.0
48.0
96.0

fi .5

13.0
26.0
52.0
104.0

fiO .O

120.0

Example
MOVL

#1,RO

MOVB

S""#CR,Rl

MOVF

#0.625,Rn

RO IS SET TO l; THE 1 IS STORED
IN THE INSTRUCTION AS A SHORT
LITERAL
THE LOW BYTE OF Rl IS SET
TO THE VALUE CR
CR IS STORED IN THE INSTRUCTION
AS A SHORT LITERAL
IF CR IS NOT IN RANGE 0-n3,
THE LINKER PRODUCES A TRUNCATION
ERROR
R6 IS SET TO THE FLOATING
POINT VALUE 0.625; IT IS STORED
IN THE FLOATING POINT SHORT
LITERAL FORM

4-9

ADDRESSING MODES

Notes
1.

When the #literal format is used, the assembler chooses
whether to use literal mode or immediate mode (see Section
4.2.4). The assembler uses immediate mode if any of the
following conditions are met:
•

The value of the literal does not fit in the short literal
form

•

The literal is a relocatable or external
Section 3.5)

•

The literal
symbols

expression

that

expression

contains

(see

undefined

The difference between immediate mode and literal mode is the
amount of storage that it takes to store the literal in the
instruction.
2.

4.2

The SA#literal format forces the
mode.

assembler

use

literal

PROGRAM COUNTER MODES

The program counter modes use PC for a general register.
There are five program counter modes:
•

Relative

•

Relative Def erred

•

Absolute

•

Immediate

•

General

4.2.1

Relative Mode

In relative mode, the address specified is the address of the operand.
The assembler stores the address as a displacement from PC.
Relative mode can be used with index mode (see Section 4.3).
Format
address
address
An expression specifying an address;
the expression can be
preceded by one of the following displacement length specifiers,
which indicate the number of bytes needed to
store
the
displacement.

4-10

ADDRESSING MODES
Displacement
Length Specifier

Meaning
Displacement requires 1 byte
Displacement requires 1 word (2 bytes)
Displacement requires 1 longword (4 bytes)

If no displacement length specifier precedes
the
address
expression and the value of the expression is known,
the
assembler chooses the smallest number of .bytes
(1,
2, or
4)
needed to store the displacement.
If no length specifier
precedes the address expression and the value of the expression
is unknown,
the assembler uses the default displacement length
(see the description of .DEFAULT in Chapter 5).
If the addreas
expression is either defined later in the program or defined in
another program section,
the assembler considers the value
unknown.

Example
MOVL

GET LONGWORD AT LABEL; THE
ASSEMBLER USES DEFAULT
DISPLACEMENT UNLESS LABEL
PREVIOUSLY DEFINED IN THIS SECTION
COMPARE RlO WITH LONGWORD AT
ADDRESS DATA+4;
THE ASSEMBLER
USES A WORD DISPLACEMENT

LABEL,Rl

CMPL

Relative Deferred Mode

4.2.2

In relative deferred mode, the address specified is the address of the
operand address (a pointer to the operand). The assembler stores the
address specified as a displacement from PC.
Relative deferred mode can be used with index mode (see Section 4.3).

Format
@address
address
An expression specifying an address;
the expression can be
preceded by one of the following displacement length specifiers,
which indicate the number of bytes needed to
store
the
displacement.

Displacement
Length Specifier

Meaning
Displacement requires 1 byte
Displacement requires 1 word (2 bytes)
Displacement requires 1 longword (4 bytes)

If no displacement length specifier precedes
the
address
expression and the value of the expression is known,
the
assembler chooses the smallest number of bytes
(1,
2, or 4)
needed to store the displacement.
If no length specifier
precedes the address expression and the value of the expression
is unknown,
the assembler uses the default displacement length
(see the description of .DEFAULT in Chapter 5).
If the address
expression is either defined later in the program or defined in
another program section,
the assembler considers the value
unknown.

4-11

ADDRESSING MODES
Example
CLRL

@W .. PNTR

INCB

@L .. COUNTS+4

CLEAR LONGWORD POINTED TO BY
LONGWORD AT PNTR; THE ASSEMBLER
USES A WORD DISPLACEMENT
INCREMENT BYTE POINTED TO BY
LONGWORD AT COUNTS+4; ASSEMBLER
USES A LONGWORD DISPLACEMENT

Absolute Mode

4.2.3

In absolute moqe, the address specified is the address of the operand.
The address is stored as an absolute virtual address (compare relative
mode, where the address is stored as a displacement from PC).
Absolute mode can be used with index mode (see Section 4.3).

Format
@#address
address
An expression specifying an address.

Example
CLRL
CLRB

@#"XllOO
@#ACCOUNT

CALLS

#3,@#SYS$FAO

CLEAR THE CONTENTS OF LOCATION llOO(HEX)
CLEAR THE CONTENTS OF LOCATION
ACCOUNT; THE ADDRESS IS STORED
ABSOLUTELY, NOT AS A DISPLACEMENT
CALL THE PROCEDURE SYS$FAO WITH
THREE ARGUMENTS ON THE STACK

Immediate Mode

4.2.4

In immediate mode, the literal specified is the operand.

Formats
#literal
I .. #literal
literal
An expression, an integer constant, or a floating-point constant.

Example
MOVL

#1000 ,RO

MOVB

#BAR,Rl

MOVF

#O.l,R6

ADDL2

I .. #5,RO

RO IS SET TO 1000; THE OPERAND 1000
IS STORED IN A LONGWORD
THE LOW BYTE OF Rl IS SET
TO THE VALUE OF BAR
R6 IS SET TO THE FLOATING
POINT VALUE 0.1; IT IS STORED
AS A 4-BYTE FLOATING POINT
VALUE (IT CAN NOT BE
REPRESENTED AS A SHORT LITERAL)
THE 5 IS STORED IN A LONGWORD
BECAUSE THE I .. FORCES THE
ASSEMBLER TO USE IMMEDIATE MODE;

4-12

ADDRESSING MODES
Notes
1.

When the #literal format
is used,
the assembler chooses
whether to use literal mode
(Section 4.1.8) or immediate
mode.
If the literal is an integer from 0 through 63 or a
floating-point constant that fits in the short literal form,
the assembler uses literal mode.
If the literal is an
expression,
the assembler uses literal mode if all the
following conditions are met:
•

The expression is absolute

•

The expression contains no undefined symbols

•

The value of the expression fits in the short literal form

In all other cases, the assembler uses immediate mode.
The difference between immediate mode and literal mode is the
amount of storage required to store the literal in the
instruction.
The assembler stores an immediate mode literal
in a byte, word, or longword depending on the operand data
type.
2.

4.2.5

The IA#literal format forces the assembler to
mode.

use

immediate

General Mode

In general mode, the address specified is the address of the operand.
The linker converts the addressing mode to either relative or absolute
mode.
If the address is relocatable, the linker converts general mode
to relative mode.
If the address is absolute, the linker converts
general mode to absolute mode.
General mode is used to write
position-independent code when the programmer does not know whether
the address is relocatable or absolute.
A general addressing mode
operand requires 5 bytes of storage.
General mode can be used with index mode (see Section 4.3).

Format

address
An expression specifying an address.

Example
CLRL

CALLS

GALABEL 1

CLEARS THE LONGWORD AT LABEL 1
IF LABEL 1 IS DEFINED AS ABSOLUTE
THEN THIS IS CONVERTED TO ABSOLUTE
MODE; IF IT IS DEFINED AS
RELOCATABLE, THEN THIS IS CONVERTED
; TO RELATIVE MODE
#5,GASYS$SERVICE ; CALLS PROCEDURE SYS$SERVICE
; WITH 5 ARGUMENTS ON STACK

4-13

ADDRESSING MODES
4.3

INDEX MODE

Index mode is a general register mode that can be used only in
combination with another mode, called the base mode. The base mode
can be any addressing mode except register, immediate, literal, index,
or branch.
The assembler first evaluates the base mode to get the
base address. Then the assembler adds the base address to the product
of the contents of the index register and the number of bytes of the
operand data type. This sum is the operand address.
Combining index mode with the
following addressing modes:

other

•

Autoincrement Index

•

Autoincrement Def erred Index

•

Autodecrement Index

•

Displacement Index

•

Displacement Def erred Index

•

Relative Index

•

Relative Deferred Index

•

Absolute Index

•

General Index

addressing

modes

The process of first evaluating the base mode and
index register is the same for each of these modes.

produces

the

adding

the

then

Formats

base-mode[Rx]
base-mode[AP)
base-mode[FP]
base-mode[SPJ
base-mode
Any addressing mode except register, immediate,
or branch, specifying the base address.

literal,

index,

A number in
register.

the

range

through

12,

specifying

Table 4-3 lists the formats of index mode addressing.

4-14

the

index

ADDRESSING MODES

Examples
;

; REGISTER DEFERRED INDEX MODE
;

DEFINE OFFS
GET ADDRESS OF BLIST
SET UP INDEX REGISTER
CLEAR BYTE WHOSE ADDRESS
IS THE ADDRESS OF BLIST
PLUS 20*1
CLEAR QUADWORD WHOSE
ADDRESS IS THE ADDRESS
OF BLIST PLUS 20*8
CLEAR OCTAWORD WHOSE
ADDRESS IS THE ADDRESS
OF BLIST PLUS 20*16

OFFS=20
MOVAB
MOVL
CLRB

BLIST,R9
#OFFS,Rl
(R9) [Rl]

CLRQ

(R9) [Rl]

CLRO

(R9) [Rl]

AUTOINCREMENT INDEX MODE
CLRW

(R9)+[Rl]

CLEAR WORD WHOSE ADDRESS
IS ADDRESS OF BLIST PLUS
20*2; R9 NOW CONTAINS
ADDRESS OF BLIST+2

AUTOINCREMENT DEFERRED INDEX MODE
MOVAL
MOVL
CLRW

POINT ,R8
#30,R2
@(R8)+[R2]

GET ADDRESS OF POINT
SET UP INDEX REGISTER
CLEAR WORD WHOSE ADDRESS
IS 30*2 PLUS THE ADDRESS
STORED IN POINT; RB NOW
CONTAINS 4 PLUS ADDRESS OF
POINT

DISPLACEMENT DEFERRED INDEX MODE
MOVAL
MOVL
TSTF

ADDARR,R9
#100 ,Rl
@40 (R9) [Rl]

GET ADDRESS OF ADDRESS ARRAY
SET UP INDEX REGISTER
TEST FLOATING POINT VALUE
WHOSE ADDRESS IS 100*4 PLUS
THE ADDRESS STORED AT (ADDARR+40)

4-15

ADDRESSING MODES
Table 4-3
Index Mode Addressing
Mode

Format*

(Rn) [Rx]

Auto increment Index

(Rn)+[Rx]

Auto increment Deferred
Index

@(Rn)+[Rx]

Autodecrement Index

- (Rn) [Rx]

Displacement Index

dis (Rn) [Rx]

Displacement Deferred
Index

@dis(Rn) [Rx]

Relative Index

address[Rx]

Relative Def erred Index

@.address[Rx]

Absolute Index

@#address[Rx]

General Index

G"'address[Rx]

* Key:
Rn
Any general register RO through Rl2 or the AP, FP,
register.

Rx
Any general register RO through Rl2 or the AP, FP, or SP
register.
Rx cannot be the same register as Rn in the
autoincrement index, autoincrement deferred index, and
decrement index addressing modes.
dis
An expression specifying a displacement.
address
An expression specifying an address.
Notes
1.

If the base mode alters the contents of its register
(autoincrement, autoincrement deferred, and autodecrement),
the index mode cannot specify the same register.

The index register is added to the address after the base
mode is completely evaluated. For example, in autoincrement
deferred index mode, the base register contains the address
of the operand address. The index register (times the length
of the operand data type) is added to the operand address
rather than to the address stored in the base register.

4-16

ADDRESSING MODES

4.4

BRANCH MODE

In branch mode, the address is stored as an implied displacement from
PC.
This mode can only be used in branch instructions.
The
displacement for conditional branch instructions
and
the
BRB
instruction is stored in a byte.
The displacement for the BRW
instruction is stored in a word (2 bytes). A byte displacement allows
a range of 127 bytes forward and 128 bytes backward.
A word
displacement allows a range of 32767 bytes forward and 32768 bytes
backward.
The displacement is relative to the updated PC, the byte
past the byte or word where the displacement is stored.
See the
VAX-11 Architecture Handbook for more information on the branch
instructions.
Format

address
address
An expression that represents an address.
Example

ADDL3

(Rl)+,RO,TOTAL

BLEQ

LABELl

BRW

LABEL

TOTAL VALUES AND SET CONDITION
CODES
BRANCH TO LABELl IF RESULT IS
LESS THAN OR EQUAL TO 0
BRANCH UNCONDITIONALLY TO LABEL

4-17

CHAPTER 5

GENERAL ASSEMBLER DIRECTIVES

The general assembler directives provide facilities for performing
eleven types of functions. Table 5-1 lists these types of functions
and the directives that fall under them.
The remainder of this
chapter describes the directives in detail, showing their formats and
giving examples of their use. For ease of reference, the directives
are presented in alphabetical order in this chapter. In addition,
Appendix B contains a summary of all assembler directives.
Table 5-1
Summary of General Assembler Directives
Directivesl

Category
Listing Control
Directives

(.LIST)
.SHOW
( .NLIST)
.NOS HOW
.TITLE
.SUBTITLE (. SBTTL)
• IDENT
.PAGE

Message Display
Directives

.PRINT
.WARN
.ERROR

Assembler Option·
Directives

.ENABLE (.ENABL)
.DISABLE (.DSABL)
.DEFAULT

Data Storage
Directives

.BYTE
.WORD
.LONG
.ADDRESS
.QUAD
.OCTA
.PACKED
.ASCII
.ASCIC
.ASCID
.ASCIZ
• F FLOATING (.FLOAT)
.D-FLOATING (.DOUBLE)
.G FLOATING
• H-FLOATING
.SIGNED BYTE
.SIGNED-WORD

1. The alternate form, if any, is given in parentheses.
(continued on next page)
5-1

GENERAL ASSEMBLER DIRECTIVES
Table 5-1 (Cont.)
Summary of General Assembler Directives
Category

Directives 1

Location Control
Directives

.ALIGN
.EVEN
.ODD
.BLKA
.BLKB
.BLKD
.BLKF
.BLKG
.BLKH
.BLKL
.BLKO
.BLKQ
.BLKW
.END

Program
Sectioning
Directives

.PSECT
.SAVE PSECT
(.SAVE)
.RESTORE PSECT (.RESTORE)

Symbol Control
Directives
Directives

.GLOBAL
( .GLOBL)
.EXTERNAL (.EXTRN)
.DEBUG
.WEAK

Routine Entry Point
Definition
Directives

.ENTRY
.TRANSFER
.MASK

Conditional
and Subconditional
Assembly
Block Directives

.IF
.ENDC
(.!FF)
.IF FALSE
• IF-TRUE
(.!FT)
• IF-TRUE FALSE (. IFTF)
.IIF
-

Cross-Reference
Directives

.CROSS
.NOCROSS

Instruction
Generation
Directives

.OPDEF
.REFl
.REF2
.REF4
.REFS
.REF16

1. The alternate form,

if any, is given in parentheses.

5-2

GENERAL ASSEMBLER DIRECTIVES

.ADDRESS
.ADDRESS -- ADDRESS STORAGE DIRECTIVE
.ADDRESS stores successive longwords containing addresses
in the
object module. DIGITAL recommends that .ADDRESS rather than .LONG be
used for storing address data to provide additional information to the
linker.
In shareable images,
addresses specified with
.ADDRESS
produce position-independent code.
See the VAX-11 MACRO User's Guide
for a discussion of specifying addresses in position-independent code.

Format
.ADDRESS address-list

Parameter
address-list
A list of symbols or expressions,
separated by commas,
that
VAX-11 MACRO interprets as addresses.
Repetition factors are not
allowed.

Example
TABLE:

.ADDRESS

LAB_4,LAB_3,ROUTTERM

5-3

REFERENCE TABLE

GENERAL ASSEMBLER DIRECTIVES

.ALIGN
.ALIGN

LOCATION COUNTER ALIGNMENT DIRECTIVE

.ALIGN aligns the location counter to the boundary specified by either
an integer or a keyword.
Formats
.ALIGN integer[,expression]
.ALIGN keyword[,expression]
Parameters
integer
An integer in the range of 0 through 9. The location counter is
aligned at an address that is the value of 2 raised to the power
of the integer.
keyword
One of five keywords that specify the alignment boundary.
The
location counter is aligned to an address that is the next
multiple of the values listed below.
Keyword

Size (in Bytes)

BYTE
WORD
LONG
QUAD
PAGE

2"0
1
2"1 = 2
2"2 = 4
2"3
8
2"9
512

expression
Specifies the fill value to be stored in each byte.
The
expression must not contain any undefined symbols and must be an
absolute expression (see Section 3.5).
Example
.ALIGN
.ALIGN
.ALIGN
.ALIGN

BYTE,O
WORD
3,"A/ I
PAGE

BYTE ALIGNMENT-FILL WITH NULL
WORD ALIGNMENT
QUAD ALIGNMENT-FILL WITH BLANKS
PAGE ALIGNMENT

Notes
1.

The alignment specified in .ALIGN cannot exceed the alignment
of the program section in which the alignment is attempted
(see the description of .PSECT). For example, if the default
program section alignment (BYTE) is being used and .ALIGN is
specified with a WORD or larger alignment, the assembler
displays an error message.

If the optional expression is supplied, the bytes skipped by
the location counter (if any) are filled with the value of
that expression. Otherwise, the bytes are zero filled.

5-4

GENERAL ASSEMBLER DIRECTIVES
3.

Although most instructions do not require any data alignment
other than byte alignment, execution speed is improved by the
following alignments:

Data Length

Alignment

Word
Longword
Quadword

5-5

GENERAL ASSEMBLER DIRECTIVES

.ASClx
.ASCix -- ASCII CHARACTER STORAGE DIRECTIVES
VAX-11 MACRO has four ASCII character storage directives:
Directive

Function

ASCII
ASCIC
ASCID
ASCIZ

ASCII string storage
Counted ASCII string storage
String-descriptor ASCII string storage
Zero-terminated ASCII string storage

Each directive is followed by a string of characters enclosed in a
pair of matching delimiters.
The delimiters can be any printable
character except the space, tab, equal sign (=), semicolon (;), or
left angle bracket {<). The character used as the delimiter cannot
appear in the string itself. Alphanumeric characters can be used as
delimiters;
however, nonalphanumeric characters should be used to
avoid confusion.
Any character except the null, carriage return, and form feed
characters can appear within the string.
The assembler does not
convert lowercase alphabetic characters to uppercase.
ASCII character storage directives convert the characters to their
8-bit ASCII value (see Appendix A) and store them one character to a
byte.
Any character, including the null, carriage return, and form feed
characters, can also be represented by an expression enclosed in angle
brackets outside of the delimiters. You must define the ASCII values
of null, carriage return, and form feed with a direct assignment
statement. The ASCII character storage directives store the 8-bit
binary value specified by the expression.
ASCII strings can be continued over several lines but the string on
each line must be delimited at both ends; however, a different pair
of delimiters can be used for each line. For example:
CR=l3
LF=lO
.ASCII
.ASCIZ
.ASCIC
.ASCII
.ASCII
.ASCII
.ASCII

/ABC DEFG/
@Any character can be delimiter@
? lowercase is not converted to UPPER?
? this is a test!?<CR><LF>!Isn't it?!
\ Angle Brackets <are part <of> this> string \
I This string is continued I \ on the next line \
<CR><LF>! this string includes an expression! -

<128+CR>? whose value is a 13 plus 128?
The following sections describe each of the four ASCII character
storage directives, giving the formats and examples of each.

5-6

GENERAL ASSEMBLER DIRECTIVES

.ASCII
.ASCII -- ASCII STRING STORAGE DIRECTIVE
.ASCII stores in the next available byte the ASCII value of each
character in the ASCII string or the value of each byte expression.
Format
.ASCII string
Parameter
string
A delimited ASCII string.
Example
CR=l3
LF=lO
.ASCII
.ASCII

"DATE:
17-NOV-1979"
/EOF/<CR><LF>

DIRECT ASSIGNMENT STATEMENTS
DEFINE CR AND LF
DELIMITER IS "
DELIMITER IS /

.ASCIC
.ASCIC -- COUNTED ASCII STRING STORAGE DIRECTIVE
.ASCIC performs the same function as
.ASCII, except that
.ASCIC
inserts a count byte before the string data.
The count byte contains
the length of the string in bytes.
The length given includes any
bytes of nonprintable characters outside the delimited string but
excludes the count byte •
• ASCIC is useful in copying text
length of the text to be copied.

because

the

count

indicates

the

Format
.ASCIC

string

Parameter
string
A delimited ASCII string.
Example
CR=l3

DIRECT ASSIGNMENT STATEMENT DEFINES CR
.ASCIC

#HELLO#<CR>

.BYTE
.ASCII

6
#HELLO#<CR>

THIS COUNTED ASCII STRING
IS EQUIVALENT TO
THE COUNT
FOLLOWED BY THE ASCII STRING

5-7

GENERAL ASSEMBLER DIRECTIVES

.ASCID
.ASCID -- STRING-DESCRIPTOR ASCII STRING STORAGE DIRECTIVE
.ASCID performs the same function as ASCII, except that .ASCID inserts
a string descriptor before the string data. The string descriptor
consists of 1) two bytes that specify the length of the string, 2) two
bytes of descriptor information, and 3)
a longword containing a
position-independent pointer to the string.
String descriptors are
used in calling procedures (see Appendix C of the VAX-11 Architecture
Handbook). Position-independence is discussed in the VAX-11 MACRO
User's Guide.

Format
.ASCID string

Parameter
string
A delimited ASCII string.

Example
DESCRl: .ASCID
DESCR2: .ASCID

PUS HAL
PUS HAL
CALLS

/ARGUMENT FOR CALL/
/SECOND ARGUMENT/

STRING DESCRIPTOR
ANOTHER ONE

DESCRl
DESCR2
#2,STRNG_PROC

PUT ADDRESS OF DESCRIPTORS
ON THE STACK
CALL PROCEDURE

.ASCIZ
.ASCIZ -- ZERO-TERMINATED ASCII STRING STORAGE DIRECTIVE
.ASCIZ performs the same function as .ASCII, except that .ASCIZ
appends a null byte as the final character of the string. Thus, when
a list or text string is created with an .ASCIZ directive, the user
need only perform a search for the null character in the last byte to
determine the end of the string.

Format
.ASCIZ string

Parameter
string
A delimited ASCII string.

Example
DEFINE FF

FF=l2
.ASCIZ

/ABCDEF/

.ASCIZ

/A/<FF>/B/

6 CHARACTERS IN STRING
7 BYTES OF DATA
3 CHARACTERS IN STRINGS
4 BYTES OF DATA
5-8

GENERAL ASSEMBLER DIRECTIVES

.BLKx
.BLKx -- BLOCK STORAGE ALLOCATION DIRECTIVES

VAX-11 MACRO has ten block storage directives:
Directive

Function

.BLKA

Reserves storage for addresses (longwords)

.BLKB

Reserves storage for byte data

.BLKD

Reserves storage for double-precision,
floating-point data (quadwords)

.BLKF

Reserves storage for single-precision,
floating-point data (longwords)

.BLKG

Reserves storage for G floating data (quadwords)

.BLKH

Reserves storage for H floating data (octawords)

.BLKL

Reserves storage for longword data

.BLKO

Reserves storage for octaword data

.BLKQ

Reserves storage for quadword data

.BLKW

Reserves storage for word data

Each directive reserves storage for a different data type. The value
of the expression determines the number of data items for which VAX-11
MACRO reserves storage. For example, .BLKL 4 reserves storage for 4
longwords of data and .BLKB 2 reserves storage for 2 bytes of data.
The total number of bytes reserved is equal to the length of the
type times the value of the expression as follows:
Directive

Number of Bytes Allocated

.BLKB

Value of expression

.BLKW

2 * value of expression

.BLKA
.BLKF
.BLKL

4 * value of expression

.BLKD
.BLKG
.BLKQ

8 * value of expression

.BLKH
.BLKO

* value of expression

5-9

data

GENERAL ASSEMBLER DIRECTIVES
Formats
.BLKA expression
.BLKB expression
.BLKD expression
.BLKF expression
.BLKG expression
.BLKH expression
.BLKL expression
.BLKO expression
.BLKQ expression
.BLKW expression

Parameter
expression
An expression specifying the amount of storage to be allocated.
All the symbols in the expression must be defined and the
expression must be an absolute expression (see Section 3.5).
If
the expression is omitted, a default value of 1 is assumed.

Example
.BLKB
.BLKO
.BLKL
.BLKF

SPACE FOR 15 BYTES
SPACE FOR 3 OCTAWORDS (48 BYTES)
SPACE FOR 1 LONGWORD (4 BYTES)
SPACE FOR 12 SINGLE PRECISION
FLOATING-POINT VALUES (48 BYTES)

15
3
1

<3*4>

5-10

GENERAL ASSEMBLER DIRECTIVES

.BYTE
.BYTE -- BYTE STORAGE DIRECTIVE
.BYTE generates successive bytes of binary data in the object module.
Format
.BYTE expression-list
Parameter
expression-list
One or more expressions separated by commas. Each expression is
first evaluated as a longword expression. Then the value of each
expression is truncated to 1 byte. The value of each expression
should be in the range of O through 255 for unsigned data or in
the range of -128 through +127 for signed data.
Each expression optionally can be followed by a repetition factor
delimited by square brackets.
An expression followed by a
repetition factor has the format:
expressionl[expression2]
expressionl
An expression that specifies the value to be stored.
[expression2]
An expression that specifies the number of times the value will
be repeated.
The expression must not contain any undefined
symbols and must be an absolute expression (see Section 3.5).
The square brackets are required.
Example
.BYTE
.BYTE
.BYTE
.BYTE

.<1024-1000>*2
AXA,FIF,10,65-<21*3>
0

X,X+3 [5*4] ,z

STORES A VALUE OF 48
STORES 4 BYTES OF DATA
STORES 1 BYTE OF DATA
STORES 22 BYTES OF DATA

Notes
1.

The assembler displays an error message if the high-order 3
bytes of the longword expression has a value other than 0 or
AXFFFFFF.

At link time, a relocatable expression can result in a value
that exceeds 1 byte. In this case, the VAX-11 Linker issues
a truncation diagnostic message for the object module in
question. For example:
A:

.BYTE

RELOCATABLE VALUE 'A' WILL
CAUSE VAX-11 LINKER TRUNCATION
DIAGNOSTIC IF THE STATEMENT
HAS A VIRTUAL ADDRESS OF 256
OR ABOVE

The .SIGNED BYTE directive is the same as .BYTE except the
assembler displays a diagnostic message if a value in the
range from 128 to 255 is specified. See the description of
.SIGNED BYTE for more information.
5-11

GENERAL ASSEMBLER DIRECTIVES

.CROSS
.NOCROSS
.CROSS AND .NOCROSS -- CROSS-REFERENCE DIRECTIVES
VAX-11 MACRO produces a cross-reference listing when the CROSS
qualifier is specified in the MACRO command. The .CROSS and .NOCROSS
directives control which symbols are included in the cross-reference
listing.
The .CROSS and .NOCROSS directives have an effect only if
/CROSS REFERENCE was specified in the MACRO command
(see the VAX-11
MACRO User's Guide).
By default, the cross-reference listing includes the definition and
all the references to every symbol in the module. The cross-reference
listing can be disabled for all symbols or for a specified list of
symbols •
• NOCROSS without a symbol list disables the cross-reference listing of
all
symbols.
.CROSS
without
a
symbol
list reenables the
cross-reference listing. Any symbol definition or reference that
appears after .NOCROSS without a symbol list and before the next
.CROSS with no argument list is excluded from the cross reference
listing •
• NOCROSS with a symbol list disables the cross-reference listing
the
listed symbols.
.CROSS with a symbol list reenables
cross-reference listing of the listed symbols.

for
the

Formats
.CROSS
.CROSS symbol-list
.NOCROSS
.NOCROSS symbol-list

Parameter
symbol-list
A list of legal symbol names separated by commas.

Examples
LABl:

.NOCROSS
MOVL
.CROSS

LOC1,LOC2

STOP CROSS REFERENCE
COPY DATA
REENABLE CROSS REFERENCE

The definition of LABl and the references to LOCl
included in the cross reference listing.
LAB2:

.NOCROSS
MOVL
.CROSS

LOCl
LOC1,LOC2
LOCl

and

LOC2

are

not

DO NOT CROSS REFERENCE LOCl
COPY DATA
REENABLE CROSS REFERENCE
OF LOCl

The definition of LAB2 and the reference to LOC2 are included in the
cross reference,
but the reference to LOCl is not included in the
cross reference.

5-12

GENERAL ASSEMBLER DIRECTIVES
Notes
1.

not
reenable
the
.CROSS without a symbol list will
cross-reference listing of a symbol specified in ~NOCROSS
with a symbol list.

If the cross-reference listing of all symbols is disabled,
.CROSS with a symbol list will have no effect until the
cross-reference listing is reenabled by .CROSS without a
symbol list.

5-13

GENERAL ASSEMBLER DIRECTIVES

.DEBUG
.DEBUG -- DEBUG SYMBOL ATTRIBUTE DIRECTIVE
.DEBUG specifies that the symbols in the list are made known to the
debugger.
During an interactive debugging session, these symbols can
be used to refer to memory locations or to examine the values assigned
to the symbols.
Format
.DEBUG symbol-list
Parameter
symbol-list
A list of legal symbols separated by commas.
Example
.DEBUG

INPUT,OUTPUT,LAB_30,LAB_40

MAKE THESE SYMBOLS KNOWN
TO THE DEBUGGER

Note
The assembler adds the symbols in the symbol list to the symbol
table in the object module.
The programmer need not specify
global symbols in the .DEBUG directive because global symbols
automatically are put in the object moduule's symbol table. See
the description of .ENABLE for information on making information
about all symbols available to the debugger.

5-14

GENERAL ASSEMBLER DIRECTIVES

.DEFAULT
.DEFAULT -- DEFAULT CONTROL DIRECTIVE
.DEFAULT determines the default displacement length for the relative
and relative deferred addressing modes (see Sections 4.2.1 and 4.2.2).
Format
.DEFAULT

DISPLACEMENT, keyword

Parameter
keyword
One of three keywords--BYTE, WORD, LONG--indicating
displacement length.

the

default

Example
.DEFAULT
DISPLACEMENT,WORD
MOVL
LABEL,Rl
.DEFAULT
DISPLACEMENT,LONG
INCB
@COUNTS+4

WORD IS DEFAULT
ASSEMBLER USES WORD
DISPLACEMENT UNLESS
LABEL HAS BEEN DEFINED
LONG IS DEFAULT
ASSEMBLER USES LONGWORD
DISPLACEMENT UNLESS
COUNTS HAS BEEN DEFINED

Notes
1.

.DEFAULT has no effect on the default displacement for
displacement and displacement deferred addressing modes (see
Sections 4.1.6 and 4.1.7).

If there is no .DEFAULT in a source module, the default
displacement length for the relative and relative deferred
addressing modes is a longword.

5-15

GENERAL ASSEMBLER DIRECTIVES

.D_FLOATING
.DOUBLE
.D FLOATING -- FLOATING POINT STORAGE DIRECTIVE
.D FLOATING evaluates the specified floating-point constants and
stores the results in the object module.
.D FLOATING generates
64-bit, double-precision, floating-point data (1 bit of sign, 8 bits
of exponent, and 55 bits of fraction).
See the description of
.F FLOATING for information on storing single precision floating point
numbers and the descriptions of .G FLOATING and .H FLOATING for
descriptions of other floating point numbers.

Format
.D FLOATING literal-list
.DOUBLE literal-list

Parameter
literal-list
A list of floating-point constants
(see Section 3.2.2).
The
constants cannot contain any unary or binary operators except
unary plus or unary minus.

Example
.D FLOATING 1000,l.OE3,l.OOOOOOOE-9
.DOUBLE
3.1415928, 1.107153423828
.D FLOATING 5, 10, 15, 0, 0.5

CONSTANT
LIST

Notes
1.

Double precision floating point numbers are always
They are not affected by .ENABLE TRUNCATION.

The floating point constants in the literal list must not
preceded by the floating point operator (AF).

5-Hi

rounded.
be

GENERAL ASSEMBLER DIRECTIVES

.DISABLE
.DISABLE -- FUNCTION CONTROL DIRECTIVE
.DISABLE disables, or inhibits, the specified assembler
See the description of .ENABLE for more information.

functions.

Format
.DISABLE argument-list
Parameter
argument-list
One or more of the symbolic arguments listed in Table 5-2 in the
description of .ENABLE. Either the long form or the short form
of the symbolic arguments can be used. If multiple arguments are
specified, they must be separated by commas, spaces, or tabs.
Note
The alternate form of .DISABLE is .DSABL.

.ENABLE
.ENABLE -- FUNCTION CONTROL DIRECTIVE
.ENABLE enables the specified assembly function.
.ENABLE and its
negative form, .DISABLE, control the following assembler functions.
•

Creating local label blocks.

•

Making all local symbols available
enabling the traceback feature.

•

Specifying that
references.

undefined

symbol

•

Truncating
numbers.

rounding

single-precision

•

Suppressing the listing of symbols that are
referenced.

•

Specifying that all PC references are absolute not relative.

the

references

debugger
are

and

external

floating-point
defined

but

not

Format
.ENABLE argument-list
Parameter
argument-list
One or more of the symbolic arguments listed in Table 5-2.
Either the long form or the short form of the symbolic arguments
can be used.
If multiple arguments are specified, they must
commas, spaces, or tabs.
5-17

separated

GENERAL ASSEMBLER DIRECTIVES

Table 5-2
.ENABLE and .DISABLE Symbolic Arguments

Long Form

Short Form

Default
Condition

Function

--------------------------+--"-'"''"___________,__________
ABSOLUTE

AMA

Disabled

When ABSOLUTE is enabled,
all PC relative addressing
modes are assembled as
absolute addressing modes.

DEBUG

DBG

Disabled

When DEBUG is enabled, all
local symbols are included
in the object module's
symbol table for use by
the debugger.

GLOBAL

GBL

Enabled

When GLOBAL is enabled,
all undefined symbols are
considered external
symbols. When GLOBAL is
disabled, any undefined
symbol that is not listed
in a .EXTERNAL directive
causes an assembly error.

LOCAL BLOCK

LSB

Disabled

When LOCAL BLOCK is
enabled, the current local
label block is ended and a
new one is started. When
LOCAL BLOCK is disabled,
the current local label
block is ended. See
Section 3.4 for a complete
description of local label
blocks.

SUPPRESSION

SUP

Disabled

When SUPPRESSION is
enabled, all symbols that
are defined but not
referred to are not listed
in the symbol table. When
SUPPRESSION is disabled,
all symbols that are
defined are listed in the
symbol table.

TRACEBACK

TBK

Enabled

When TRACEBACK is enabled,
the program section names
and lengths, module names,
and routine names are
included in the object
module for use by the
debugger. When TRACEBACK
is disabled, VAX-11 MACRO
excludes this information
and, in addition, does not
make any local symbol
information available to
the debugger.
(continued on next page)

5-18

GENERAL ASSEMBLER DIRECTIVES

Table 5-2 (Cont.)
.ENABLE and .DISABLE Symbolic Arguments

Long Form

Short Form

Default
Condition

TRUNCATION

FPT

Disabled

Function
When TRUNCATION is
enabled, single-precision
floating-point numbers are
truncated. When
TRUNCATION is disabled,
single-precision
floating-point numbers are
rounded. D floating,
G floating,-and H floating
numbers are not affected
by .ENABLE TRUNCATION;
they are always rounded.

Example

.ENABLE ABSOLUTE, GLOBAL

ASSEMBLE RELATIVE ADDRESS MODE
AS ABSOLUTE ADDRESS MODE.
UNDEFINED REFERENCES ARE GLOBAL

• DISABLE TRUNCATION,TRACEBACK

ROUND FLOATING-POINT NUMBERS •
DO NOT PUT ANY DEBUGGING
INFORMATION INTO OBJECT MODULE

Note

The alternate form of .ENABLE is .ENABL.

5-19

GENERAL ASSEMBLER DIRECTIVES

.END
.END -- ASSEMBLY TERMINATION DIRECTIVE
.END terminates the source program. No additional text should occur
beyond this point in the current source file or in any additional
source files specified in the command line for this assembly. If any
additional text does occur, the assembler ignores the text. The
additional text does not appear in either the listing file or the
object file.
Format
.END [symbol]
Parameter
symbol
The address (called the
execution is to begin.

transfer

address)

which

program

Example
.ENTRY

START,O

.END

START

ENTRY MASK
MAIN PROGRAM

Notes
1.

The transfer address must be in a program section
the EXE attribute (see the description of .PSECT).

that

has

When an executable image consisting of several object modules
is linked, only one object module should be terminated by an
.END directive that specifies a transfer address. All other
object modules should be terminated by .END directives that
do not specify a transfer address. If an executable image
either contains no transfer address or contains more than one
transfer address, the VAX-11 Linker displays an
error
message.

If the source program contains an unterminated conditional
code
block when the .END directive is specified, the
assembler displays an error message •

. ENDC
.ENDC -- END CONDITIONAL DIRECTIVE
.ENDC terminates the conditional range started by the .IF directive.
See the description of .IF for more information and examples.
Format
.ENDC

5-20

GENERAL ASSEMBLER DIRECTIVES

.ENTRY
.ENTRY -- ENTRY DIRECTIVE
.ENTRY defines a symbolic name for an entry point and stores a
register save mask (2 bytes) at that location. The symbol is defined
as a global symbol with a value equal to the value of the location
counter at the .ENTRY directive. The entry point can be used as the
transfer address of the program. The register save mask is used to
determine which registers are saved before the procedure is called.
These saved registers are automatically restored when the procedure
returns control to the calling program. See the description of the
procedure call instructions in the VAX-11 Architecture Handbook.
Format
.ENTRY symbol,expression
Parameter
symbol
The symbolic name for the entry point.
expression
The register save mask for the entry point. The expression must
be an absolute expression and must not contain any undefined
symbols.
Example
.ENTRY

CALC,"M<R2,R3,R7>

PROCEDURE STARTS HERE.
REGISTERS 2,3,7 ARE
PRESERVED BY CALL AND
RET INSTRUCTIONS

Notes
1.

The. register mask operator ("M) is convenient to use for
setting the bits in the register save mask (see Section
3.6.2.2).

An assembly error occurs if the expression has bits O, 1, 12,
or 13 set.
These bits correspond to the registers RO, Rl,
AP, and FP and are reserved for the CALL interface.

DIGITAL recommends that .ENTRY be used to define all callable
entry points including the transfer address of the program.
Although the following construct also defines an entry point,
its use is discouraged:
symbo 1 : : • WORD

expression

Although a procedure starting with this construct can be
called, the entry mask 1s not checked for any illegal
registers and the symbol cannot be used in a .MASK directive.

5-21

GENERAL ASSEMBLER DIRECTIVES
4.

.ENTRY should be used only for procedures that will be called
by the CALLS or CALLG instruction. A routine that is entered
by the BSB or JSB instruction should not use .ENTRY because
these instructions do not expect a register save mask. These
routines should begin in the following format:
symbol::

first instruction

The first instruction of the routine immediately follows
symbol.

5-22

the

GENERAL ASSEMBLER DIRECTIVES

.ERROR
.ERROR -- ERROR DIRECTIVE

.ERROR causes the assembler to display an error message on the
terminal or batch log file and in the listing file (if there is one).
Format

.ERROR [expression]

comment

Parameters

expression
An expression whose value is displayed when .ERROR is encountered
during assembly.
comment
A comment that is displayed when .ERROR is encountered
assembly. The comment must be preceded by a semicolon.

during

Example

• IF DEFINED
.IF GREATER
.ERROR 25
.ENDC
.ENDC

LONG MESS
lOoo=woRK AREA
; NEED LARGER WORK AREA

If the symbol LONG MESS is defined and if the symbol WORK AREA has
value of 1000 or less, the following error message is displayed:
%MACRO-E-GENERR, Generated ERROR:

25 NEED LARGER WORK AREA

Notes

.ERROR, .WARN, and .PRINT are called the message display
directives.
They
can be used to display information
indicating that a macro call contains an error or an illegal
set of conditions
(see Chapter n for more information on
macro calls).

When the assembly is finished, the assembler displays the
total number of errors, warnings, and information messages,
and the sequence numbers of the lines causing the errors or
warnings on the terminal. See the VAX-11 MACRO User's Guide
for more information on errors and warnings.

If .ERROR is included in a macro library (see the VAX-11
MACRO
User's
Guide), the comment should end with an
additional semicolon. Otherwise, the librarian will strip
the comment from the directive and it will not be displayed
when the macro is called.

The line containing the .ERROR directive is not
the listing file.

included

If the expression has a value of O, it is
the error message.

displayed

5-23

not

GENERAL ASSEMBLER DIRECTIVES

.EVEN
.EVEN -- EVEN LOCATION COUNTER ALIGNMENT DIRECTIVE
.EVEN ensures that the current value of the location counter is even
by adding 1 if the current value is odd. If the current value is
already even, no action is taken.
Format
.EVEN

.EXTERNAL
.EXTERNAL -- EXTERNAL SYMBOL ATTRIBUTE DIRECTIVE
.EXTERNAL indicates that specified symbols are external; that is, the
symbols are defined in another object module and cannot be defined
until link time (see Section 3.3.3).
Format
.EXTERNAL symbol-list
Parameter
symbol-list
A list of legal symbols separated by commas.
Example
.EXTERNAL
.EXTERNAL

SIN,TAN,COS
SINH,COSH,TANH

THESE SYMBOLS ARE DEFINED IN
EXTERNALLY ASSEMBLED MODULES

Notes
1.

If the GLOBAL argument is enabled (see Table 5-2 in the
description of .ENABLE), all unresolved references will be
marked as global and external. Thus, if GLOBAL is enabled,
the programmer need not specify .EXTERNAL.
However, if
GLOBAL is disabled, the programmer must explicitly specify
.EXTERNAL to declare any symbols that are defined externally
but referred to in the current module.

If GLOBAL is disabled and the assembler finds symbols that
are not defined in the current module and are not listed in a
.EXTERNAL directive, the assembler displays an error message.

The alternate form of .EXTERNAL is .EXTRN.

5-24

GENERAL ASSEMBLER DIRECTIVES

.f_FLOATING

.FLOAT
.F FLOATING (.FLOAT) -- FLOATING-POINT STORAGE DIRECTIVE
.F FLOATING evaluates the specified floating-point constants and
stores the results in the object module.
.F FLOATING generates
32-bit, single-precision, floating-point data {l bit of sign, 8 bits
of exponent,
and 23 bits of fractional significance).
See the
description of .D FLOATING for information on storing double-precision
floating-point
numbers and the descriptions of .G FLOATING and
.H FLOATING for descriptions of other floating point numbers.

Format
.F FLOATING literal-list
.FLOAT literal-list

Parameter
literal-list
A list of floating-point constants
{see Section 3.2.2).
The
constants cannot contain any unary or binary operators except
unary plus and unary minus.

Example
• F FLOATING
• F-FLOATING
• F-FLOATING
.FLOAT

134.5782,74218.34E20
134.2,0.1342E3,1342E-l
-0.75,1E38,-l.OE-37
0,25,50

SINGLE PRECISION
THESE ALL GENERATE 134.2
DATA
LIST

Notes
1.

See the description of .ENABLE for information on
floating-point rounding or truncation.

The floating point constants in the literal list must not
preceded by the floating point unary operator {AF).

5-25

specifying
be

GENERAL ASSEMBLER DIRECTIVES

.G_FLOATING
.G FLOATING -- G FLOATING POINT STORAGE DIRECTIVE
G FLOATING evaluates the specified floating-point constants and stores
tne results in the object module.
.G FLOATING generates n4-bit data
( 1 bi t of s i g n , 11 bi ts- of ex pone n t , and 5 2 bi ts of f r action ) •

Format
.G FLOATING literal-list

Parameters
literal-list
A list of G floating point constants (see Section 3.2.2).
The
constants cannot contain any unary or binary operators except
unary plus or unary minus.

Example
.G FLOATING

1000,

l.OE3,

l.OOOOOOOE-9

;constant list

Notes
1.

G floating point numbers are always rounded.
affected by the .ENABLE TRUNCATION directive.

are

not

The floating point constants in the literal list must not
preceded by the floating point operator (AF).

5-26

They

GENERAL ASSEMBLER DIRECTIVES

.GLOBAL
.GLOBAL -- GLOBAL SYMBOL ATTRIBUTE DIRECTIVE
.GLOBAL indicates that specified symbol names are either globally
defined in the current module or externally defined in another module
(see Section 3.3.3).

Format
.GLOBAL symbol-list

Parameter
symbol-list
A list of legal symbol names separated by commas.
Example
.GLOBAL LAB_40,LAB_30

MAKE THESE SYMBOL NAMES
GLOBALLY KNOWN
TO ALL LINKED MODULES

.GLOBAL UKN 13

Notes
1.

.GLOBAL is provided for MACR0-11 compatibility only.
DIGITAL
recommends that global definitions be specified by a double
colon or double equals sign (see Section 2.2.1 and 3.8)
and
that external references be specified by .EXTERNAL (when
necessary).

2. The alternate form of .GLOBAL is .GLOBL.

5-27

GENERAL ASSEMBLER DIRECTIVES

.H_FLOATING
.H FLOATING -- H FLOATING POINT STORAGE DIRECTIVE

H FLOATING evaluates the specified floating-point constants and stores
the results in the object module. .H FLOATING generates 128-bit data
(1 bit of sign, 15 bits of exponent, and 112 bits of fraction).
Format
.H FLOATING literal-list

Parameters
literal-list
A list of H floating point constants (see Section 3.2.2).
The
constants cannot contain any unary or binary operators exc~pt
unary plus or unary minus.
Example
;constant list

FLOATING

H floating point numbers are always rounded.
affected by the .ENABLE TRUNCATION directive.

are

not

The floating point constants in the literal list must not
preceded by the floating point operator (~F).

36912,

15.0E18,

l.OOOOOOOE-9

Notes

5-28

They

GENERAL ASSEMBLER DIRECTIVES

.IDENT
.!DENT -- IDENTIFICATION DIRECTIVE
.!DENT provides a means of identifying the object module.
This
identification is in addition to the name assigned to the object
module with .TITLE. A character string can be specified in .!DENT to
label the object module. This string is printed in the header of the
listing file as well as appearing in the object module.
Format
.!DENT string
Parameter
string
A 1- to 31-character string that identifies the module, such as a
string that specifies a version number.
The string must be
delimited. The delimiters can be any paired printing characters,
other than the left angle bracket (<) or the semicolon (;), as
long as the delimiting character is not contained in the text
string itself.
Example
• !DENT

/3-47 I

; VERSION AND EDIT NUMBERS

The character string 3-47 is included in the object module.
Notes
1.

If one source module contains more than one .!DENT, the last
directive given establishes the character string that forms
part of the object module identification.

If the delimiting characters do not match, or if an illegal
delimiting character is used, the assembler displays an error
message.

5-29

GENERAL ASSEMBLER DIRECTIVES

.IF
.IF -- CONDITIONAL ASSEMBLY BLOCK DIRECTIVES
A conditional assembly block is a series of source statements that is
assembled only if a certain condition is met.
.IF starts the
conditional block and .ENDC ends the conditional block.
Each .IF must
have a corresponding .ENDC. The .IF directive contains a condition
test and one or two arguments.
The condition test specified is
applied to the argument(s).
If the test is met, all MACRO statements
between .IF and .ENDC are assembled.
If the test
is not met,
the
statements are not assembled.
An exception to this occurs when
subconditional directives are used
(see the description of
.IF x
directive).
Conditional blocks can be nested, that is a conditional block can be
inside of another conditional block.
In this case the statements in
the inner conditional block are assembled only if the condition is met
for both the outer and inner block.
Format
.IF condition argument(s)

range

.ENDC
Parameters
condition
A specified condition that must be met if the block is to be
included in the assembly.
Table 5-3 lists the conditions that
can be tested by the conditional assembly directives.
The
condition must be separated from the argument(s) by a comma,
space, or tab.
argument(s)
The symbolic argument(s)
or expression{s)
of the specified
conditional test.
If the argument is an expression, it cannot
contain any undefined symbols and must be an absolute expression
(see Section 3.5).
range
The block of source code that is conditionally
assembly.

5-30

included

the

GENERAL ASSEMBLER DIRECTIVES
Table 5-3
Condition Tests for Conditional Assembly Directives

Complement
Condition Test

Long
Form

Short
Form

Long
Form

Short
Form

EQUAL

NOT_EQUAL

Expression

Expression is equal to
O /not equal to O

GREATER

LESS_EQUAL

Expression

Expression is greater
than O /less than or
equal to 0

LESS THAN

GREATER_EQUAL

Expression

Expression is less
than O /greater than
or equal to 0

DEFINED

NOT DEFINED

NDF

Symbolic

Symbol is defined /not
defined

BLANK 1

NOT BLANK 1

Macro

Argument is blank
/nonblank

IDENTICAL l

IDN

DIFFERENT l

DIF

Macro

Arguments are
identical /different

Argument Type

Number of
Arguments

Condition that
Assembles Block

Condition Test

1. The BLANK, NOT BLANK, IDENTICAL, and DIFFERENT conditions are only
useful
in macro definitions. Chapter n describes macro directives in
detail.

Examples
1.

An example of a conditional assembly directive is:
.IF EQUAL

ALPHA+l

ASSEMBLE BLOCK IF ALPHA+l=O
DO NOT ASSEMBLE IF ALPHA+l NOT=O

.ENDC
2.

Nested conditional directives take the form:
.IF
.IF

condition,argument(s)
condition,argument(s)

.ENDC
.ENDC

5-31

GENERAL ASSEMBLER DIRECTIVES
3.

The following conditional
assembly is to occur:
.IF DEFINED
.IF DEFINED

directives

can

govern

whether

SY Ml
SYM2

.ENDC
.ENDC
In this example, if the outermost condition is not satisfied, no
deeper level of evaluation of nested conditional statements within the
program occurs. Therefore, both SYMl and SYM2 must be defined for the
code to be assembled.
Notes
1.

If .ENDC occurs outside a conditional
assembler displays an error message.

VAX-11 MACRO permits a nesting depth of 31 conditional
assembly levels.
If a statement attempts to exceed this
nesting level depth, the assembler displays an error message.

The assembler displays an error message if .IF specifies any
of the following: a condition test other than those in Table
5-3, an illegal argument, or a null argument specified in an
.IF directive.

The .SHOW and .NOSHOW directives control whether condition
blocks that are not assembled are included in the listing
file.

5-32

assembly

block,

the

GENERAL ASSEMBLER DIRECTIVES

.IF_x
.IF x -- SUBCONDITIONAL ASSEMBLY BLOCK DIRECTIVES
VAX-11 MACRO has three subconditional assembly block directives:
Directive

Function

.IF FALSE

If the condition of the assembly block tests
false, the program is to include the source code
following the .IF FALSE directive and continuing
up to the next subconditional directive or to the
end of the conditional assembly block.

.IF TRUE

If the condition of the assembly block tests true,
the
program
is to include the source code
following the .IF TRUE directive and continuing up
to the next subconditional directive or to the end
of the conditional assembly block •

• IF TRUE FALSE Always include the source code fo)lowing the
.IF TRUE FALSE directive and continuing up to the
next subconditional directive or to the end of the
conditional assembly block. This source code is
included regardless of whether the condition of
the assembly block tests true or false.
The implied argument of a subconditional directive is the condition
test specified when the conditional assembly block was entered. A
conditional or subconditional directive in a nested conditional
assembly block is not evaluated if the preceding (or outer) condition
in the block is not satisfied (see examples 3 and 4 below).
A conditional block with a subconditional directive is different than
a nested conditional block. If the condition in the .IF is not met,
the inner conditional block(s) are not assembled, but a subconditional
directive can cause a block to be assembled.
Formats
.IF FALSE
• IF-TRUE
.IF-TRUE FALSE

5-33

GENERAL ASSEMBLER DIRECTIVES
Examples
1.

Assume that symbol SYM is defined:
• IF DEFINED

SYM

TESTS TRUE SINCE SYM IS DEFINED.
ASSEMBLES THE FOLLOWING CODE.

.IF FALSE

TESTS FALSE SINCE PREVIOUS
.IF WAS TRUE. DO NOT
ASSEMBLE THE FOLLOWING CODE.

• IF TRUE

TESTS TRUE. SYM IS DEFINED •
ASSEMBLES THE FOLLOWING CODE •

• IF TRUE FALSE

ASSEMBLES FOLLOWING CODE
UNCONDITIONALLY •

• IF. TRUE

TESTS TRUE. SYM IS DEFINED.
ASSEMBLES REMAINDER OF
CONDITIONAL ASSEMBLY BLOCK •

• ENDC
2.

Assume that symbol
• IF DEFINED
.IF DEFINED

x is defined and that symbol Y is not defined:

TESTS TRUE. SYMBOL X IS DEFINED •
TESTS FALSE. SYMBOL Y IS NOT
DEFINED.
TESTS TRUE. SYMBOL Y IS NOT
DEFINED.
ASSEMBLES THE FOLLOWING CODE.

.IF FALSE

TESTS FALSE. SYMBOL Y IS NOT
DEFINED.
DOES NOT ASSEMBLE THE FOLLOWING
CODE •

.IF TRUE

• ENDC
.ENDC
3.

Assume that symbol A is defined and that symbol B is not defined:
.IF DEFINED

TESTS TRUE. A IS DEFINED.
ASSEMBLES THE FOLLOWING CODE.

.IF FALSE

TESTS FALSE. A IS DEFINED. DOES
NOT ASSEMBLE THE FOLLOWING CODE.

.IF NOT DEFINED B

NESTED CONDITIONAL DIRECTIVE
IS NOT EVALUATED •

• ENDC
.ENDC

5-34

GENERAL ASSEMBLER DIRECTIVES
4.

Assume that symbol X is not defined but symbol Y is defined:

• IF DEFINED

TESTS FALSE. SYMBOL X IS NOT
DEFINED.
DOES NOT ASSEMBLE THE
FOLLOWING CODE.
NESTED CONDITIONAL DIRECTIVE
IS NOT EVALUATED.

• IF FALSE

NESTED SUBCONDITIONAL
DIRECTIVE IS NOT EVALUATED •

• IF TRUE

NESTED SUBCONDITIONAL
DIRECTIVE IS NOT EVALUATED •

• ENDC
.ENDC
Notes

If a subconditional directive appears outside a conditional
assembly block, the assembler displays an error message.

The
alternate
forms
of
.IF FALSE,
.IF TRUE FALSE are .!FF, .!FT, and-.IFTF.

5-35

• IF_TRUE,,

and

GENERAL ASSEMBLER DIRECTIVES

.llF'
.IIF

IMMEDIATE CONDITIONAL ASSEMBLY BLOCK DIRECTIVE

.IIF provides a means of writing a one-line conditional assembly
block.
The condition to be tested and the conditional assembly block
are expressed completely within the line containing
the
.IIF
directive; no terminating .ENDC statement is required.
Format
.IIF condition argument(s), statement
Parameters
condition
One of the legal condition tests defined for conditional assembly
blocks in Table 5-3 (See the description of .IF). The condition
must be separated from the argument(s) by a comma, space, or tab.
argument(s)
The argument associated with the immediate conditional directive;
that is, an expression or symbolic argument (described in Table
5-3). If the argument is an expression, it cannot contain any
undefined symbols and must be an absolute expression (see Section
3.3.3). The argument(s) must be separated from the statement by
a comma.
statement
The statement to be assembled if the condition is satisfied.
Example
Condition Argument

Statement

.IIF DEFINED EXAM,

BEQL

ALPHA

This directive generates the following code
defined within the source program:
BEQL

the

symbol

EXAM

ALPHA

Note
The assembler displays an error message if .IIF specifies any of
the following: a condition test other than those listed in Table
5-3, an illegal argument, or a null argument.

5-36

GENERAL ASSEMBLER DIRECTIVES

.LIST
.LIST

LISTING DIRECTIVE

.LIST is equivalent to the .SHOW.
more information.

See the description

.SHOW

for

Formats
.LIST
.LIST argument-list
Parameter
argument-list
One or more of the symbolic argument defined in Table 5-7 in the
description of .SHOW. Either the long form or the short form of
the arguments can be used. If multiple arguments are specified,
they must be separated by commas, spaces, or tabs.

5-37

GENERAL ASSEMBLER DIRECTIVES

.LONG
.LONG -- LONGWORD STORAGE DIRECTIVE
.LONG generates successive longwords (4 bytes) of data in
module.

the

object

Format
.LONG expression-list
Parameters
expression-list
One or more expressions separated by commas.
Each expression
optionally can be followed by a repetition factor delimited by
square brackets.
An expression followed by a repetition factor has the format:
expressionl[expression2]
expressionl
An expression that specifies the value to be stored.
[expression2]
An expression that specifies the number of times the value will
be repeated.
The expression must not contain any undefined
symbols and must be an absolute expression (see Section 3.5).
The square brackets are required.
Example
LAB 3:

.LONG
.LONG
.LONG

LAB 3,AX7FFFFFFF,AA'ABCD'
AXF@4
0[22]

3 LONGWORDS OF DATA
1 LONGWORD OF DATA
22 LONGWORDS OF DATA

Note
Each expression in the list
represented in 32 bits.

must

5-38

have

value

that

can

GENERAL ASSEMBLER DIRECTIVES

.MASK
.MASK -- MASK DIRECTIVE
.MASK reserves a word for a register save mask for a transfer vector.
See the description of .TRANSFER for more information and for an
example of .MASK.
Format
.MASK symbol[,expression]
Parameters
symbol
A symbol defined in an .ENTRY directive.
expression
A register save mask.
Notes
1.

If .MASK does not contain an expression, the assembler
directs the linker to copy the register save mask specified
in .ENTRY to the word reserved by .MASK.

If .MASK contains an expression, the assembler directs the
linker to combine this expression with the register save mask
specified in .ENTRY and store the result in the word reserved
by .MASK.
The linker performs an inclusive OR operation to
combine the mask in the entry point and the value of the
expression.
Consequently, a register specified in either
.ENTRY or .MASK will be included in the combined mask.
See
the description of .ENTRY for more information on entry
masks.

.NLIST
.NLIST

LISTING DIRECTIVE

.NLIST is equivalent to .NOSHOW.
more information.

See the

description

.SHOW

for

Formats
.NLIST
.NLIST argument-list
Parameter
argument-list
One or more of the symbolic arguments listed in Table 5-7 in the
description of .SHOW. Either the long form or the short form of
the arguments can be used. If multiple arguments are specified,
they must be separated by commas, spaces, or tabs.

5-39

GENERAL ASSEMBLER DIRECTIVES

.NOCROSS
.NOCROSS -- CROSS REFERENCE DIRECTIVE
VAX-11 MACRO produces a cross-reference listing when the CROSS
qualifier is specified in the MACRO command. The .CROSS and .NOCROSS
directives control which symbols are included in the cross-reference
listing. The description of .NOCROSS is included with the description
of .CROSS.
Formats
.NOCROSS
.NOCROSS symbol-list
Parameter
symbol-list
A list of legal symbol names separated by commas •

. NOSHOW
.NOSHOW -- LISTING DIRECTIVE
.NOSHOW specifies listing control options.
.SHOW for more information.

See

the

description

Formats
.NOSHOW
.NOSHOW argument-list
Parameter
argument-list
One or more of the symbolic arguments listed in Table 5-7 in the
description of .SHOW. Either the long form or the short form of
the arguments can be used. If multiple arguments are specified,
they must be separated by commas, spaces, or tabs.

5-40

GENERAL ASSEMBLER DIRECTIVES

.OCTA
.OCTA -- OCTAWORD STORAGE DIRECTIVE
.OCTA generates 128 bits (16 bytes) of binary data.
Format
.OCTA literal
.OCTA symbol
Parameters
literal
Any constant value. This value can be preceded by Ao, AB, AX, or
AD to specify the radix as octal, binary, hexadecimal, or
decimal, respectively; or it can be preceded by AA to specify
ASCII text. Decimal is the default radix.
symbol
A symbol defined elsewhere in the program. This symbol results
in a sign-extended, 32-bit value being stored in an octaword.
Example
.OCTA

AA"FEDCBA987654321"

.OCTA
.OCTA
.OCTA

EACH ASCII CHARACTER IS STORED
IN A BYTE
OCTA 0
OCTA HEX VALUE SPECIFIED
VINTERVAL HAS A 32 BIT VALUE
SIGN EXTENDED

AX01234ABCD5678F9
VINTERVAL

Note
.OCTA is like .QUAD and unlike other data storage directives
(.BYTE,
.WORD,
and .LONG) in that it does not evaluate
expressions and that it accepts only one value.
It does not
accept a list.

.ODD
.ODD -- ODD LOCATION COUNTER ALIGNMENT DIRECTIVE
.ODD ensures that the current value of the location counter is odd by
adding 1 if the current value is even. If the current value is
already odd, no action is taken.
Format
.ODD

5-41

GENERAL ASSEMBLER DIRECTIVES

.OPDEF
.OPDEF -- OPCODE DEFINITION DIRECTIVE
.OPDEF defines an opcode, which it inserts into a user-defined opcode
table.
The assembler searches this table before it searches the
permanent symbol table.
This directive can redefine an existing
opcode name or create a new one.
Format
.OPDEF

opcode

value,operand-descriptor-list

Parameters
opcode
An ASCII string specifying the name of the opcode.
The string
can be up to 31 characters long and can contain the letters A
through z; the digits 0 through 9; and the special characters
underline { ) , dollar sign {$), and period (.). The string
should not start with a digit and should not be surrounded by
delimiters.
value
An expression that specifies the value of the opcode.
The
expression must not contain any undefined values and must be an
absolute expression {see - Section 3.5).
The value of
the
expression must be in the range of 0 through decimal 65535
{hexadecimal FFFF), but the values 252 through 255 cannot be
used. The expression is represented as follows:
if 0 < expression < 251
i f expression

expression is a one-byte opcode.
expression bits 15:8 are the
first byte of the opcode and
expression bits 7:0 are
the
second byte of the opcode.

> 255

Values 252 through 255 cannot be used because the architecture
specifies these as the start of a two-byte opcode. Note that
this representation does not correspond to the representation of
these numbers in memory.
operand-descriptor-list
A list of operand descriptors that specifies the number of
operands and the type of each. Up to lfi operand descriptors are
allowed in the list. Table 5-4 lists the operand descriptors.

5-42

GENERAL ASSEMBLER DIRECTIVES
Table 5-4
Operand Descriptors
---------------- ---------.
Data Type
Access
Type

Byte

Word

Longword

Read-only

Modify

Write-only

Field

Branch

---- -

Address

Flo a ting Double
Floating
Po in t
Point
··-·

G floating
Point

H floating
Point

Quadword

Octaword

-+-·-----

---

'-------------'-----

Examples
.OPDEF

MOVL3

.OPDEF
.OPDEF
.OPDEF

DIVF2
MOVC5
CALL

; DEFINES AN
INSTRUCTION, MOVL3, WHICH USES
THE RESERVED OPCODE FF.
~X46,RF,MF
; REDEFINES THE DIVF2 AND
~X2C,RW,AB,AB,RW,AB
; MOVC5 INSTRUCTIONS.
~XlO,BB
; EQUIVALENT TO A BSBB
~XFFA9,RL,ML,WL

Notes
1.

A macro can also be used to redefine an opcode (see the
description of .MACRO in Chapter 6). Note that the macro
name table is searched before the user-defined opcode table.

.OPDEF is useful in creating "custom" instructions that
execute us~r-written microcode. This directive is supplied
to allow programmers to execute their microcode in a MACRO
program.

The operand descriptors are specified in a format similar to
the operand specifier notation described in the VAX-11
Architecture Handbook. The first character specifies the
operand access type and the second character specifies the
operand data type.

5-43

GENERAL ASSEMBLER DIRECTIVES

.PACKED
.PACKED -- PACKED DECIMAL STRING STORAGE DIRECTIVE
.PACKED generates packed decimal data, 2 digits per byte.
Packed
decimal data is useful in calculations requiring exact accuracy.
Packed decimal data is operated on by the decimal string instructions.
See the VAX-11 Architecture Handbook for more information on the
format of packed decimal data.
Format
.PACKED decimal-string[,symbol]
Parameters
decimal-string
A decimal number from 0 through 31 digits long with an optional
sign. Each digit can be in the range of 0 through 9 (see Section
3.2.3).
symbol
An optional symbol that is assigned a value equivalent to the
number of decimal digits in the string. The sign is not counted
as a digit.
Example
.PACKED -12,PACK SIZE
.PACKED +500
.PACKED 0
.PACKED -0,SUM_SIZE

PACK SIZE GETS VALUE OF 2
SUM SIZE GETS VALUE OF 1

.PAGE
.PAGE -- PAGE EJECTION DIRECTIVE
.PAGE forces a new page in the listing;
printed in the listing.

the directive itself

VAX-11 MACRO ignores .PAGE in a macro definition.
operation is performed only during macro expansion.
describes macro directives and facilities in detail.
Format
.PAGE

5-44

not

The paging
Chapter 6

GENERAL ASSEMBLER DIRECTIVES

.PRINT
.PRINT -- ASSEMBLY MESSAGE DIRECTIVE
.PRINT causes the assembler to display an informational message.
The
message consists of the value of the expression and the comment
specified in the .PRINT directive. The message is displayed on the
terminal for interactive jobs and in the log file for batch jobs. The
message produced by .PRINT is not considered an error or warning
message.
Format
.PRINT [expression] ;comment
Parameters
expression
An expression whose value is displayed when .PRINT is encountered
during assembly.
comment
A comment that is displayed when .PRINT is encountered
assembly. The comment must be preceded by a semicolon.

during

Example
.PRINT

THE SINE ROUTINE HAS BEEN CHANGED

Notes
1.

.PRINT, .ERROR, and .WARN are called the message display
directives.
They
can be used to display information
indicating that a macro call contains an error or an illegal
set of conditions (See Chapter 6 for more information on
macro calls) •

If .PRINT is included in a macro library (see the VAX-11
MACRO
User's
Guide), the comment should end with an
additional semicolon.
Otherwise, the comment
will
be
stripped from the directive and will not be displayed when
the macro is called.

If the expression has a value of
the message.

5-45

o, it is not displayed

with

GENERAL ASSEMBLER DIRECTIVES

.PSECT
.PSECT -- PROGRAM SECTIONING DIRECTIVE
.PSECT defines a program section and its attributes and
program section once it is defined.

refers

Program sections can be used to:
•

Develop modular programs

•

Separate instructions from data

•

Allow different modules to access the same data

•

Protect read-only data and instructions from being modified

•

Identify sections of the object module to the debugger

•

Control the order in which
virtual memory

See the VAX-11 MACRO
program sections.

User's

program

Guide

for

sections

are

information

stored
on

using

The assembler automatically defines two program sections:
the
absolute program section and the unnamed (or blank) program section.
Any symbol definitions that appear before any instruction, data, or
.PSECT directive are placed in the absolute program section. Any
instructions or data that appear before the first named program
section is defined are placed in the unnamed program section. Any
.PSECT directive that does not include a program section name
specifies the unnamed program section.
A maximum of 254 user-defined, named program sections can be defined.
When the assembler encounters a .PSECT directive that specifies a new
program section name, it creates a new program section and stores the
name, attributes, and alignment of the program section. The assembler
includes all data and instructions that follow the .PSECT directive in
that program section until it encounters another .PSECT directive.
The assembler starts all program sections at a location counter of 0
which is relocatable.
If the assembler encounters a .PSECT directive that specifies the name
of a previously defined progr~m section, it stores the new data or
instructions after the last entry in the previously defined program
section.
The location counter is set to the value of the location
counter at the end of the previously defined program section.
The
programmer need not list the attributes when continuing a program
section but any attributes that are listed must be the same as those
previously in effect for the program section. A continuation of a
program section cannot contain attributes conflicting with those
specified in the original .PSECT directive.
The attributes listed in the .PSECT directive only describe the
contents of the program section.
The assembler does not check to
ensure that the contents of the program section actually include the
attributes listed.

5-46

GENERAL ASSEMBLER DIRECTIVES
However, the assembler and the linker do check that all program
sections with the same name have exactly the same attributes. The
assembler and linker display an error message if the program section
attributes are not consistent.
Program section names are independent of local symbol, global symbol,
and macro names.
Thus, the same symbolic name can be used for a
program section and for a local symbol, global symbol, or macro name.
Formats
.PSECT
.PSECT program section-name[,argument-list]
Parameters
program-section-name
The name of the program section. This name can be up to 31
characters long and can contain any alphanumeric character and
the underline ( ) , dollar sign ($), and period (.) characters.
However, the first character must not be a digit.
argument-list
A list containing the program section attributes and the program
section alignment.
Table 5-5 lists the attributes and their
functions. Table 5-6 lists the default attributes and their
opposites.
Program sections are aligned when an integer in the
range of 0 through 9 is specified or when one of the five
keywords listed below is specified. If an integer is specified,
the program section is linked to begin at the next virtual
address that is a multiple of 2 raised to the power of the
integer. If a keyword is specified, the program section is
linked to begin at the next virtual address that is a multiple of
the values listed below:
Keyword

Size (in Bytes)

BYTE
WORD
LONG
QUAD
PAGE

2"'0
1
2"'1 = 2
2"'2
4
2"'3
8
2"'9
512

BYTE is the default.

5-47

GENERAL ASSEMBLER DIRECTIVES
Table 5-5
Program Section Attributes
Attribute
Name

Function

-------+---·----·-·--··-------··--------------------~

ABS

Absolute--The linker assigns the program section an
absolute
address.
The contents of the program
section can be only symbol definitions (usually
definitions of symbolic offsets to data structures
that are used by the routines being assembled).
An
absolute program section contributes no binary code
to the image, so its byte allocation request to the
linker is O.
The size of the data structure being
defined is the size of the absolute program section
printed in the "program section synopsis" at the end
of the listing.
Compare this attribute with its
opposite, REL.

CON

Concatenate--Program sections with the same name
attributes
(including CON) are merged into
program section. Their contents are merged in
order
in which the linker acquires them.
allocated virtual address space is the sum of
individual requested allocations.

EXE

Executable--The
program
section
contains
instructions. This attribute provides the capability
of separating instructions
from
read-only
and
read/write data.
The linker uses this attribute in
gathering program sections and in verifying that the
transfer address is in an executable program section.

GBL

Global--Program sections that have the same name and
attributes, including GBL and OVR, will have the same
relocatable address in memory even when the program
sections are in different clusters (see the VAX-11
Linker Reference Manual for more information on
clusters).
This attribute is specified for FORTRAN
COMMON block program sections (see the VAX-11 FORTRAN
User's Guide).
Compare this attribute with its
opposite, LCL.

LCL

Local--The program section is restricted to its
cluster.
Compare this attribute with its opposite,
GBL.

LIB

Library Segment--Reserved for future use.

NO EXE

Not Executable--The program section contains
only; it does not contain instructions.

NOP IC

Non-Position-Independent Content--The program section
is assigned to a fixed location in virtual memory
(when it is in a shareable image).

NORD

Nonreadable--Reserved for future use.

NOS HR

No Share--The program section is reserved for private
use at execution time by the initiating process.

and
one
the
The
the

data

(continued on next page}

5-48

GENERAL ASSEMBLER DIRECTIVES
Table 5-5 (Cont.)
Program Section Attributes
Attribute
Name

Function

NOWRT

Nonwritable--The program section's contents cannot be
altered (written into) at execution time.

OVR

Overlay--Program sections with the same name and
attributes, including OVR, have the same relocatable
base address in memory.
The allocated
virtual
address space is the requested allocation of the
largest overlaying program section.
Compare this
attribute with its opposite, CON.

PIC

Position-Independent Content--The program section can
be relocated;
that is, it can be assigned to any
memory area {when it is in a shareable image).

Readable--Reserved for future use.

REL

Relocatable--The linker assigns the program section a
relocatable
base address.
The contents of the
program section can be code or data.
Compare this
attribute with its opposite, ABS.

SHR

Share--The program section can be shared at execution
time
by multiple processes.
This attribute is
assigned to a program section that can be linked into
a shareable image.

USR

User Segment--Reserved for future use.

VEC

vector-Containing--The program section contains a
change mode vector indicating a privileged shareable
image. The SHR attribute must be used with VEC.

Write--The program section's contents can be
(written into) at execution time.

Table 5-6
Default Program Section Attributes
Default
Attribute

Opposite
Attribute

CON
EXE
LCL
NOP IC
NOS HR
RD
REL
WRT
NOV EC

OVR
NO EXE
GBL
PIC
SHR
NORD
ABS
NOWRT
VEC

5-49

altered

GENERAL ASSEMBLER DIRECTIVES
Examples
.PSECT

CODE,NOWRT,EXE,LONG

.PSECT

RWDATA,WRT,NOEXE,QUAD

PROGRAM SECTION TO CONTAIN
EXECUTABLE CODE
PROGRAM SECTION TO CONTAIN
MODIFIABLE DATA

Notes
1.

The .ALIGN directive cannot specify an alignment greater than
that of the current program section; consequently, .PSECT
should specify the largest alignment needed in the program
section.
For efficiency of execution, an alignment of
longword or larger is recommended for all program sections
that have longword data.

The attributes of the def a ult absolute and the default
unnamed program sections are listed below. Note that the
program section names include the periods and enclosed
spaces.

Program Section
Name
ABS
• BLANK •

Attributes and Alignment
NOPIC,USR,CON,ABS,LCL,NOSHR,NOEXE,NORD,NOWRT,NOVEC,BYTE
NOPIC,USR,CON,REL,LCL,NOSHR,NOEXE,RD,WRT,NOVEC,BYTE

5-50

GENERAL ASSEMBLER DIRECTIVES

.QUAD
.QUAD -- QUADWORD STORAGE DIRECTIVE

.QUAD generates 64 bits (8 bytes) of binary data.
Format

.QUAD literal
.QUAD symbol
Parameters

literal
Any constant value. This value can be preceded by Ao, AB, AX, or
AD to specify the radix as octal, binary, hexadecimal, or
decimal, respectively; or it can be preceded by AA to specify
the ASCII text operator. Decimal is the default radix.
symbol
A symbol defined elsewhere in the program. This symbol results
in a sign-extended, 32-bit value being stored in a quadword.
Example

.QUAD

AA I • • ASK? •• I

.QUAD
.QUAD
.QUAD
.QUAD

AX0123456789ABCDEF
AB1111000111001101
LABEL

EACH ASCII CHARACTER IS STORED
IN A BYTE
QUAD 0
QUAD HEX VALUE SPECIFIED
QUAD BINARY VALUE SPECIFIED
LABEL HAS A 32 BIT
VALUE ZERO EXTENDED.

Note

.QUAD is like .OCTA and different from other data storage
directives (.BYTE, .WORD, and .LONG) in that it does not evaluate
expressions and that it accepts only one value.
It does not
accept a list.

5-51

GENERAL ASSEMBLER DIRECTIVES

.REFn
.REFn -- OPERAND GENERATION DIRECTIVES
VAX-11 MACRO has five operand generation
(see Chapter 6) to define new opcodes:

directives

Directive

Function

.REFl

Generates a byte operand

.REF2

Generates a word operand

.REF4

Generates a longword operand

.REF8

Generates a quadword operand

.REF16

Generates an octaword operand

used

macros

The .REFn directives are provided for compatibility with VAX-11 MACRO
Vl.O.
The
.OPDEF directive provides greater functionality and is
easier to use than .REFn;
consequently, .OPDEF should be used instead
of .REFn.

Formats
.RE·Fl
.REF2
.REF4
.REF8
.REF16

operand
operand
operand
operand
operand

Parameter
operand
An operand of byte,
context, respectively.

word,

longword,

quadword,

octaword

Example
.MACRO
.BYTE
.REF4
.REF4
.REF4
.ENDM

MOVL3 A,B,C
"XFF,"XA9

MOVL3

RO,@LAB-l,(R7)+[Rl0]

A
B

THIS OPERAND HAS LONGWORD CONTEXT
THIS OPERAND HAS LONGWORD CONTEXT
THIS OPERAND HAS LONGWORD CONTEXT

MOVL3

This example uses .REF4 to create a new instruction, MOVL3, which uses
the reserved opcode FF.
See the example in .OPDEF for a preferred
method to create a new instruction.

GENERAL ASSEMBLER DIRECTIVES

. RESTORE_PSECT
.RESTORE PSECT -- RESTORE PREVIOUS PROGRAM SECTION CONTEXT DIRECTIVE
.RESTORE PSECT retrieves the program section from the top of the
program section context stack, an internal stack in the assembler.
If
the stack is empty when .RESTORE PSECT is issued, the assembler
displays an error message. When-.RESTORE PSECT retrieves a program
section, it restores the current location counter to the value it had
when the program section was saved. The local label block is also
restored if it was saved when the program section was saved. See the
descriptipn of .SAVE_PSECT.

Format
.RESTORE PSECT

Example
.RESTORE PSECT and .SAVE PSECT are especially useful in macros
that
define program sections
(see Chapter 6).
The macro
definition below saves the current program section context and
defines new program sections.
Then,
it restores the saved
program section.
If the macro did not save and restore the
program section context each time the macro was invoked, the
program section would change •
• MACRO

INITD

INITIALIZE SYMBOLS
AND DATA AREAS
SAVE THE CURRENT PSECT
DEFINE NEW PSECT
DEFINE SYMBOLS

.SAVE PSECT
.PSECT SYMBOLS,ABS
HELP LEV=2
MAXNUM=lOO
RATE1=16
RATE2=4
.PSECT DATA,NOEXE,LONG
TABL:
.BLKL
100
TEMP:
.BLKB
16
.RESTORE PSECT

DEFINE ANOTHER PSECT
100 LONGWORDS IN TABL
MORE STORAGE
RESTORE THE PSECT
IN EFFECT WHEN
MACRO IS INVOKED

.ENDM

Note
The alternate form of .RESTORE PSECT is .RESTORE.

5-53

GENERAL ASSEMBLER DIRECTIVES

.SAVE_PSECT
.SAVE PSECT -- SAVE CURRENT PROGRAM SECTION CONTEXT DIRECTIVE
.SAVE PSECT stores the current program section context on the top of
the program section context stack, an internal assembler stack, while
leaving the current program section context in effect.
The program
section context stack can hold 31 entries.
Each entry includes the
value of the current location counter and the maximum value assigned
to the location center in the current program section.
If the stack
is full when .SAVE_PSECT is encountered, an error occurs •
• SAVE PSECT and .RESTORE PSECT are especially useful
in macros that
define program sections (s~e Chapter fi).
See the description of
.RESTORE PSECT for another example of using .SAVE PSECT.
Format
.SAVE PSECT [LOCAL_BLOCK]
Parameter
LOCAL BLOCK
An optional keyword that specifies that the current
is to be saved with the program section context.

local

label

Example
MACRO DEFINITION:
.MACRO

ERR_MESSAGE, TEXT

; SET UP LISTS OF MESSAGES AND
; POINTERS
.IIF NOT DEFINED
MESSAGE INDEX, MESSAGE INDEX=O
.SAVE PSECT
LOCAL BLOCK
KEEP LOCAL LABELS
.PSECT MESSAGE TEXT
LIST OF ERROR MESSAGES
MESSAGE:: .ASCIC /TEXT/ADDRESSES OF ERROR MESSAGES
.PSECT MESSAGE POINTERS
STORE ONE POINTER
.ADDRESS
-MESSAGE
GET BACK LOCAL LABELS
.RESTORE PSECT
PUSHL
#MESSAGE INDEX
PRINT MESSAGE
CALLS
#1, PRINT_MESS
MESSAGE INDEX=MESSAGE INDEX+l
.ENDM
ERR MESSAGE
MACRO CALL:
RESETS: CLRL
R4
BLBC
RO, 30$
;
<STRING TOO SHORT>
ADD "STRING TOO SHORT"
ERR MESSAGE
; TO LIST OF ERROR MESSAGES
30$:
RSB
The use of .SAVE PSECT LOCAL BLOCK here means that the local label 30$
is defined in tne same locaT label block as the reference to 30$.
If
a local label is not defined in the block in which it is referenced,
the assembler produces the following error message:
%MACRO-E-UNDEFSYM, Undefined Symbol
Note
1.

The alternate form of .SAVE PSECT is .SAVE.

5-54

GENERAL ASSEMBLER DIRECTIVES

.SHOW
.NOSHOW
.SHOW AND .NOSHOW -- LISTING DIRECTIVES
.SHOW and .NOSHOW specify listing control options in the source text
of a program.
.SHOW and .NOSHOW can be used with or without an
argument 1 ist.
When used with an argument list, .SHOW causes certain types of lines
to be included in the listing file and .NOSHOW causes certain types of
lines to be excluded.
.SHOW and .NOSHOW control the listing of the
source lines that are in conditional assembly blocks (see the
description of .IF}, macros, and repeat blocks (see Chapter n}.
When used without arguments, these directives alter the listing level
count.
The listing level count is initialized to o. Each time .SHOW
appears in a program, the listing level count is incremented;
each
time .NOSHOW appears in a program, the listing level count is
decremented.
When the listing level count is negative, the listing is suppressed
(unless the line contains an error}. Conversely, when the listing
level count is positive, the listing is generated. When the count is
O, the line is either listed or suppressed, depending on the value of
the listing control symbolic arguments.

Formats
.SHOW
.SHOW argument-list
.NOSHOW
.NOSHOW argument-list

Parameter
argument-list
One or more of the optional symbolic arguments, defined in Table
5-7. Either the long form or the short form of the arguments can
be used. Each argument can be used alone or in combination with
other arguments. If multiple arguments are specified, they must
be separated by commas, tabs, or spaces. If any argument is not
specifically included in a listing control statement, its default
value (Show or Noshow} is assumed throughout the source program.

5-55

GENERAL ASSEMBLER DIRECTIVES
Table 5-7
.SHOW and .NOSHOW Symbolic Arguments

...

~--~·-·-----.--·------·----~.------------r---------------

Long Form

Short Form

Default

Function

BINARY

MEB

No show

Lists macro expansions and
repeat block expansions
that generate binary code.
BINARY is a subset of
EXPANSIONS.

CALLS

Show

Lists macro calls and
repeat block specifiers.

CONDITIONALS

CND

Show

Lists unsatisfied
conditional code
associated with the
conditional assembly
directives.

DEFINITIONS

Show

Lists macro and repeat
range definitions that
appear in an. input source
file.

EXPANSIONS

No show

Lists macro and repeat
range expansions.

'-------~-"--··-----·-------

'---·-·-- ___

..___··--·~-------~~---~--J

Example
.MACRO

.SHOW

LIST NEXT LINE.

.NOS HOW

DO NOT LIST REMAINDER OF MACRO
EXPANSION •

X=.

• ENDM
DO NOT LIST MACRO EXPANSIONS •

• NOSHOW EXPANSIONS

xx
X=.
Notes
1.

The listing level count allows macros
to
be
listed
selectively;
a macro definition can specify .NOSHOW at the
beginning to decrement the listing count and can specify
.SHOW at the end to restore the listing count to its original
value.

The alternate forms
.NLIST.

.SHOW

5-56

and

.NOSHOW

are

.LIST

and

GENERAL ASSEMBLER DIRECTIVES

.SIGNED_BVTE
.SIGNED BYTE -- SIGNED BYTE DATA DIRECTIVE
.SIGNED BYTE is equivalent to .BYTE, except that VAX-11
MACRO
indicates that the data is signed in the object module. The linker
uses this information to test for overflow conditions.
Format
.SIGNED BYTE expression-list
Parameters
expression-list
An expression or list of expressions separated by commas.
Each
expression optionally can be followed by a repetition factor
delimited by square brackets.
An expression followed by a repetition factor has the format:
expressionl[expression2]
expressionl
An expression that specifies the value to be stored.
must be in the range -128 to +127.

The

value

[expression2]
An expression that specifies the number of times the value will
be repeated.
The expression must not contain any undefined
symbols and must be an absolute expression (see Section 3.5).
The square brackets are required.
Example
.SIGNED BYTE
.SIGNED-BYTE

LABEL1-LABEL2
ALPHA [ 20]

DATA MUST FIT
IN BYTE

Note
Specifying .SIGNED BYTE allows the linker to detect overflow
conditions when the value of the expression is in the range of
128 through 255. Values in this range can be stored as unsigned
data but cannot be stored as signed data in a byte.

5-57

GENERAL ASSEMBLER DIRECTIVES

.SIGNED_WORD
.SIGNED_WORD -- SIGNED WORD STORAGE DIRECTIVE
.SIGNED WORD is equivalent to .WORD except that the
assembler
indicates that the data is signed in the object module. The linker
uses this information to test for overflow conditions.
.SIGNED WORD
is useful after the case instruction to ensure that the displacement
fits in a word.
Format
.SIGNED WORD expression-list
Parameters
expression-list
An expression or list of expressions separated by commas.
Each
expression optionally can be followed by a repetition factor
delimited by square brackets.
An expression followed by a repetition factor has the format:
expressionl[expression2]
expression!
An expression that specifies the value to be stored.
must be in the range -32768 to +32767.

The

value

CASE,SRC,DISPLIST,TYPE=W,LIMIT=#O,NMODE=SA#,?BASE,?MAX
MACRO TO USE CASE INSTRUCTION
SRC IS SELECTOR, DISPLIST IS LIST
OF DISPLACEMENTS, TYPE IS B-BYTE
W-WORD, L-LONG, LIMIT IS THE BASE
; VALUE OF SELECTOR
CASE'TYPE
SRC,LIMIT,NMODE'<<MAX-BASE>/2>-1
CASE INSTRUCTION
BASE:
LOCAL LABEL SPECIFYING BASE
.IRP
EP,<DISPLIST>
TO SET UP OFFSET LIST
.SIGNED WORD
EP-BASE
OFFSET LIST
.ENDR MAX:
LOCAL LABEL USED TO COUNT ARGS
CASE
.ENDM
CASE
CASEW

IVAR
<ERR PROC,SORT,REV SORT>
IVAR,#0,SA#<(30001$-30000$)/2>-l

5-58

IF IVAR=O, ERROR;

GENERAL ASSEMBLER DIRECTIVES
30000$:
.SIGNED WORD
.SIGNED-WORD
.SIGNED-WORD
30001$:

ERR PROC-30000$
SORT-30000$
REV SORT-30000$

LOCAL LABEL SPECIFYING BASE
; OFFSET LIST
; -OFFSET LIST
; OFFSET LIST
LOCAL LABEL USED TO COUNT ARGS
=l, FOWARD SORT; =2,BACKWARD SORT

CASE
CASEL

TEST
<TEST1,TEST2,TEST3>,L,#l
TEST,#l,SA#<<30003$-30002$>/2>-l
; LOCAL LABEL SPECIFYING BASE
30002:
; OFFSET LIST
.SIGNED WORD
TESTl-30002$
.SIGNED-WORD
TEST2-30002$
; OFFSET LIST
.SIGNED-WORD
; OFFSET LIST
TEST3-30002$
LOCAL LABEL USED TO COUNT ARGS
30003$:
VALUE OF TEST CAN BE 1,2, OR 3
In this example, the CASE macro 'uses .SIGNED WORD to create a CASEB,
CASEW, or CASEL instruction. See Chapter 6 for a description of the
directives used to define the macro.

Note
Specifying .SIGNED WORD allows the linker to detect overflow
conditions when the value of the expression is in the range of
32768 through 65535. Values in this range can be stored as
unsigned data but cannot be stored as signed data in a word.

5-59

GENERAL ASSEMBLER DIRECTIVES

.SUBTITLE
.SUBTITLE -- SUBTITLE DIRECTIVE
.SUBTITLE causes the assembler to print a line of text in the table of
contents that is produced immediately before the assembly listing.
The assembler also prints the line of text as the subtitle on the
second line of each assembly listing page. This subtitle text is
printed on each page until altered by a subsequent .SUBTITLE directive
in the program.
Format
.SUBTITLE comment-string
Parameter
comment-string
An ASCII string from 1 to 40 characters long;
excess characters
are truncated.
This string represents the line of text to be
printed in the table of contents and as the subtitle in the
assembly listing.
Example

.SUBTITLE CONDITIONAL ASSEMBLY
This directive causes the assembler to print
text as the subtitle of the assembly listing:

the

following

CONDITIONAL ASSEMBLY
It also causes the text to be printed out in the listing's
table of contents, along with the source page number and the
line sequence number of the source statement where
.SUBTITLE
was
specified.
The table of contents would have the
following format:

TABLE OF CONTENTS
(1)
(2)
(2)
(3)
(4)
(4)
(5)

5000 ASSEMBLER DIRECTIVES
300 MACRO DEFINITIONS
2300 DATA TABLES AND INITIALIZATION
4800 MAIN ROUTINE
2800 CALCULATIONS
5000 I/O ROUTINES
1300 CONDITIONAL ASSEMBLY

Note
The alternate form of .SUBTITLE is .SBTTL.

5-60

GENERAL ASSEMBLER DIRECTIVES

.TITLE
.TITLE -- TITLE DIRECTIVE

.TITLE assigns a name to the object module. This name is the first 31
or fewer nQnblank characters following the directive.
Format

.TITLE module-name comment-string
Parameters

module-name
An identifier from 1 to 31 characters long.
comment-string
An ASCII string from 1 to 40 characters long;
are truncated.

excess

characters

Example

.TITLE

EVAL

EVALUATES EXPRESSIONS

Notes

The module name specified with .TITLE bears no relationship
to the file specification of the object module, as specified
in the VAX-11 MACRO command line. Rather, the object module
name appears in the linker load map, and is also the module
name that the debugger and librarian recognize.

If .TITLE is not specified, MACRO assigns the default name
.MAIN.
to the object module.
If more than one .TITLE
directive is specified in the source program, the last .TITLE
directive encountered establishes the name for the entire
object module.

When evaluating the module-name, MACRO ignores all spaces
and/or tabs up to the first nonspace/nontab character after
.TITLE.

5-61

GENERAL ASSEMBLER DIRECTIVES

.TRANSFER
.TRANSFER -- TRANSFER DIRECTIVE

.TRANSFER redefines a global symbol for use in a shareable image. The
linker redefines the symbol as the value of the location counter at
the .TRANSFER directive after a shareable image is linked.
Whenever possible, programs should not need to be relinked when the
shareable images to which they are linked change. This can only be
achieved if:
•

the total size of the shareable image does not change

•

the entry points in the shareable image do not change their
addresses when the shareable code is changed and the image is
relinked.

To avoid changing the size of the shareable image, reserve extra space
when first creating the image. To insure that the entry points do not
change, create an object module that contains a transfer vector for
each entry point and does not change the order of the transfer
vectors. Link this object module at the beginning of the shareable
image and the addresses will remain fixed even if source code for a
routine is changed. After each .TRANSFER directive, a register save
mask (for procedures only) and a branch to the first instruction of
the routine should appear.
The .TRANSFER directive does not cause any memory to be allocated and
does not generate any binary code. It merely generates instructions
to the linker to redefine the symbol when a shareable image is being
created •
• TRANSFER can be used with procedures entered by the CALLS or CALLG
instruction.
In this case, .TRANSFER is used with the .ENTRY and
.MASK directives. The branch to the actual routine must be a branch
to the entry point plus 2. Adding 2 to the address is necessary to
bypass the 2-byte register save mask.
Figure 5-1 illustrates the use of transfer vectors.

5-62

GENERAL ASSEMBLER DIRECTIVES

Linked with Object Modules

Linked with Shareable Image

Program
Calling
Procedure

Transfer
Vector
Module

..
.
CALLS

Program
Calling
Procedure

ROUTB

.
.TRANSFER
.MASK
BRW
.TRANSFER
.MASK
BRW

CALLS

ROUTB---

ROUT A
ROUT A
ROUTA+2
ROUTB~

ROUTB
ROUTB+2-+-

Shareable
Image

Other
Object
Modules

ROUTB,O
.ENTRY
; START OF ROUTINE..._1-

ENTRY
ROUTB,O ...............
; START OF ROUTINE

RET

Figure 5-1

Object
Modules

Using Transfer Vectors

5-n3

GENERAL ASSEMBLER DIRECTIVES
Format
.TRANSFER symbol
Parameter
symbol
A global symbol that is an entry point in a procedure or routine.
Example
.TRANSFER ROUTINE A
.MASK
ROUTINE=A,AM<R4,R5>
BRW

ROUTINE A+2

.ENTRY

ROUTINE_A,AM<R2,R3>

COPY ENTRY MASK
AND ADD REGISTERS
4 AND 5
BRANCH TO ROUTINE
(PAST ENTRY MASK)

ENTRY POINT, SAVE
REGISTERS 2 AND 3

RET
In this example, .MASK copies a routine's entry mask to the new entry
address specified by .TRANSFER.
If the routine is placed in a
shareable image and then called, registers 2, 3, 4, and 5 will be
saved.

5-64

GENERAL ASSEMBLER DIRECTIVES

.WARN
.WARN -- WARNING DIRECTIVE
.WARN causes the assembler to display a warning message on the
terminal or batch log file and in the listing file (if there is one).
Format
.WARN [expression] ;comment
Parameters
expression
An expression whose value is displayed when .WARN is
during assembly.

encountered

;comment
A comment that is displayed when .WARN
comment must be preceded by a semicolon.

encountered.

The

Example
• IF DEFINED
• IF DEFINED
.WARN
.ENDC
.ENDC

FULL
DOUBLE PREC
; THIS-COMBINATION NOT TESTED

If the symbols FULL and DOUBLE PREC are both
warning message is displayed. %MACRO-W-GENWRN, Generated WARNING:

defined,

the

following

THIS COMBINATION NOT TESTED

Notes
1.

.WARN, .ERROR, and .PRINT are called the message display
directives.
They
can be used to display information
indicating that a macro call contains an error or an illegal
set of conditions (see Chapter n for more information on
macro calls) •

When the assembly is finished, the assembler displays the
total number of errors, warnings, and information messages,
and the page numbers and line numbers of the lines causing
the errors or warning on the terminal (or in the batch log
file).
See the VAX-11 MACRO User's
Guide
for
more
information on errors and warnings.

If .WARN is included in a macro ~ibrary (see the VAX-11 MACRO
User's Guide), the comment should end with an additional
semicolon. Otherwise, the comment will be stripped from the
directive and will not be displayed when the macro is called.

The line containing the .WARN directive is not included
the listing file.
If the expression has a value of O, it is not displayed
the warning message.

5-65

in
in

GENERAL ASSEMBLER DIRECTIVES

.WEAK
.WEAK -- WEAK SYMBOL ATTRIBUTE DIRECTIVE
.WEAK specifies symbols that are either defined externally in another
module or defined globally in the current module. .WEAK suppresses
any object library search for the symbol.
When .WEAK specifies a symbol that is not defined in the current
module, the symbol is externally defined. If the linker finds the
symbol's definition in another module, it uses that definition.
If
the linker does not find an external definition, the symbol has a
value of 0 and the linker does not report an error. The linker does
not search a library for the symbol, but if a module brought in from a
library for another reason contains the symbol definition, the linker
uses it.
When .WEAK specifies a symbol that is defined in the current module,
the symbol is considered to be globally defined. However, if this
module is inserted in an object library, this symbol is not inserted
in the library's symbol table. Consequently, searching the library at
link time to resolve this symbol does not cause the module to be
included.
Format
.WEAK

symbol-list

Parameter
symbol-list
A list of legal symbols separated by commas.
Example
.WEAK

IOCAR,LAB_3

5-66

GENERAL ASSEMBLER DIRECTIVES

.WORD
.WORD -- WORD STORAGE DIRECTIVE
.WORD generates successive words (2
module.

bytes)

data

the

object

Format
.WORD

expression-list

Parameter
expression-list
One or more expressions separated by commas.
Each expression
optionally can be followed by a repetition factor delimited by
square brackets.
An expression followed by a repetition factor has the format:
expressionl[expression2]
expressionl
An expression that specifies the value to be stored.
[expression2]
An expression that specifies the number of times the value will
be repeated.
The expression must not contain any undefined
symbols and must be an absolute expression (see Section 3.5).
The square brackets are required.
Example
.WORD

"X3F,FIVE[3] ,32

Notes
1. The expression is first evaluated as a longword, then
truncated to a word. The value of the expression should be
in the range of -32768 through 32767 for signed data or O
through 65535 for unsigned data. The assembler displays an
error if the high-order 2 bytes of the longword expression
have a value other than O or "XFFFF.
2.

The .SIGNED WORD directive is the same as .WORD except that
the assembler displays a diagnostic message if a value is in
the range from 32768 to 65535.

5-67

CHAPTER 6
MACROS

By using macros, a programmer can use a
sequence of source lines into a program.

single

line

insert

A macro definition contains the source lines of the macro. The macro
definition
can optionally have formal arguments.
These formal
arguments can be used throughout the sequence of source lines. Later,
the formal arguments are replaced by the actual arguments in the macro
call.
The macro call consists of the macro name optionally followed by
actual arguments.
The assembler replaces the line containing the
macro call with the source lines in the macro definition. It replaces
any occurrences of formal arguments in the macro definition with the
actual arguments specified in the macro call. This process is called
the macro expansion.
By default, macro expansions are not printed in the assembly listing.
They are printed only when the .SHOW directive (see description in
Chapter 5), or the /SHOW qualifier, described in the VAX-11 MACRO
User's Guide, specifies the EXPANSIONS argument. In the examples in
this chapter, the macro expansions are listed as they would appear if
.SHOW EXPANSIONS was specified in the source file or /SHOW EXPANSIONS
was specified in the MACRO command string.
The macro directives provide facilities
for
performing
eight
categories of functions.
Table 6-1 lists these categories and the
directives that fall under them.
Section 6.1 describes
macro
arguments.
Section 6.2 describes the directives in detail. For ease
of reference, the directives are presented in alphabetical order.

6-1

MACROS

Table 6-1
Summary of Macro Directives
Directives 1

Category
Macro Definition
Directives

.MACRO
.ENDM

Macro Library
Directives

• LIBRARY
.MCALL

Macro Deletion
Directive

.MDELETE

Macro Exit
Directive

.MEXIT

Argument Attribute
Directives

.NARG
.NCHR
.NTYPE

Indefinite Repeat
Block Directives

.IRP
• IRPC

Repeat Block
Directives

.REPEAT (.REPT)

End Range
Directive

.ENDR

'-----------~----''----"·-~-·-···

·----·-----

1. The alternate form, if any, is given in parentheses.

6.1

ARGUMENTS IN MACROS

Macros have two types of arguments:
actual and formal.
Actual
arguments are the strings given in the macro call after the name of
the macro. Formal arguments are specified by name in the macro
definition:
that is, after the macro name in the .MACRO directive.
Actual arguments in macro calls and formal arguments in macro
definitions can be separated by commas, tabs, or spaces.
The number of actual arguments in the macro call can be less than or
equal to the number of formal arguments in the macro definition.
But if the number of actual arguments is greater than the number of
formal arguments, the assembler displays an error message.
Formal and actual arguments normally maintain a strict positional
relationship.
That is, the first actual argument in a macro call
replaces all occurrences of the first formal argument in the macro
definition.
However, this strict positional relationship can be
overridden by the use of keyword arguments (see Section 6.1.2).
An example of a macro definition using formal arguments follows:
.MACRO
.LONG
.WORD
.BYTE
.ENDM

STORE
ARGl
ARG3
ARG2
STORE

ARG1,ARG2,ARG3
ARGl IS FIRST ARGUMENT
ARG3 IS THIRD ARGUMENT
ARG2 IS SECOND ARGUMENT

6-2

MACROS

The following two examples show possible calls and expansions
macro defined above.

STORE
.LONG
.WORD
.BYTE

3,2,1
3
1
2

MACRO CALL
3 IS FIRST ARGUMENT
1 IS THIRD ARGUMENT
2 IS SECOND ARGUMENT

STORE
.LONG
.WORD
.BYTE

X,X-Y,Z

MACRO CALL
X IS FIRST ARGUMENT
Z IS THIRD ARGUMENT
X-Y IS SECOND ARGUMENT

6.1.1

x
z

X-Y

the

Default Values

Default values are values that are defined in the macro definition.
They are used when no value is specified in the macro call for a
formal argument.
Default values are specified in the .MACRO directive as follows:
formal-argument-name = default-value
An example of a macro definition specifying default values follows:
.MACRO
.LONG
.WORD
.BYTE
.ENDM

STORE
ARGl
ARG3
ARG2
STORE

ARG1=12,ARG2=0,ARG3=1000

The following three examples show possible calls and expansions of the
macro defined above.
1.

STORE
.LONG
.WORD
.BYTE

NO ARGUMENTS SUPPLIED
12
1000
0

STORE
.LONG
.WORD
.BYTE

1
1
1000
0

6.1.2

Keyword Arguments

,5,X
12

LAST TWO ARGUMENTS SUPPLIED

5
FIRST ARGUMENT SUPPLIED

Keyword arguments allow a macro call to specify the arguments
in any
order;
however, the macro call must specify the same formal argument
names that appear in the macro definition.
Keyword arguments are
useful when a macro definition has many formal arguments, only some of
which need to be specified in the call.
In any one macro call the arguments should be either all positional
arguments or all keyword arguments.
When positional and keyword
arguments are combined in a macro,
only the positional arguments

6-3

MACROS
correspond by position to the formal arguments; the keyword arguments
are not used. If a formal argument corresponds to both a positional
argument and a keyword argument, the argument that appears last in the
macro call overrides any other argument definition for the same
argument.
For example, the following macro definition specifies three arguments:
.MACRO
.LONG
.WORD
.BYTE
.ENDM

STORE
ARGl
ARG3
ARG2
STORE

ARGl ,ARG2 ,ARG3

The following macro call specifies keyword arguments:
STORE
.LONG
.WORD
.BYTF

ARG3=27+5/4,ARG2=5,ARGl=SYMBL
SYMBL
27+5/4
5

Because the keywords are specified in the macro call, the arguments in
the macro call need not be given in the order they were listed in the
macro definition.

6.1.3

String Arguments

If an actual argument is a string containing characters that the
assembler interprets as separators (such as a tab, space, or comma),
the string must be enclosed by delimiters.
String delimiters are
usually paired angle brackets (<>).
However, the assembler also
interprets any character after an initial circumflex (A) as a
delimiter.
Thus, to pass an angle bracket as part of a string, the
programmer can use the circumflex form of the delimiter.
The following are examples of delimited macro arguments:
<HAVE THE SUPPLIES RUN OUT?>
<LAST NAME, FIRST NAME>
<LAB:
CLRL
R4>
A%ARGUMENT rs <LAST,FIRST> FOR CALL%
A?EXPRESSION IS <5+3>*<4+2>?
In the last two examples the initial circumflex indicates that the
percent sign (%)
and question mark
(?),
respectively, are the
delimiters. Note that only the left hand delimiter is preceded by a
circumflex.
The assembler interprets a string argument enclosed by delimiters as
one actual argument and associates it with one formal argument. If a
string argument that contains separator characters is not enclosed by
delimiters, the assembler interprets it as successive actual arguments
and associates it with successive formal arguments.
For example, the following macro call has one formal argument.
.MACRO
.ASCII
.ASCII
.ENDM

REPEAT STRNG
/STRNG/
/STRNG/
REPEAT

'i-4

MACROS

The following two macro calls demonstrate actual
without delimiters.
1.

REPEAT
.ASCII
.ASCII

arguments

with

and

<A B C D E>
/A B C D E/
/A B C D E/

REPEAT A B C D E
%MACRO-E-TOOMNYARGS, Too many arguments in MACRO call

Note that the assembler interpreted the second macro call as having
five actual arguments instead of one actual argument with spaces.
When a macro is called, the assembler removes
present) around a string before associating
arguments.

the delimiters (if
it with the formal

If a string contains a semicolon, the string must be enclosed by
delimiters, or the semicolon will mark the start of the comment field.
To pass a number containing a radix or unary operator (for example,
"XF19), the entire argument must be enclosed by delimiters, or the
assembler will interpret the radix operator as a delimiter.
The
following are macro arguments that are enclosed in delimiters because
they contain radix operators:
<"XF19>
<"'BOllOOOll>
<"'Fl.5>
Macros can be nested, that is a macro definition can contain a call to
another macro. If within a macro definition, another macro is called
and passed a string argument, the programmer must delimit the argument
so that the entire string is passed to the second macro as one
argument.
The following macro definition contains a call
defined in an earlier example:
LABl:

the

REPEAT

.MACRO
.BYTE

CNTRPT LAB1,LAB2,STR ARG
LAB2-LAB1-l
LENGTH OF 2+STRING

REPEAT

.ENDM

CNTRPT

macro

CALL REPEAT MACRO

LAB2:
Note that the argument in the call to REPEAT is enclosed in angle
brackets even though the actual argument does not contain any
separator characters. This is done because the actual argument in the
call to REPEAT is a formal argument in the macro definition and will
be replaced with an actual argument that may contain separator
characters.
The following example calls the macro CNTRPT which in turn
macro REPEAT:
ST:

CNTRPT
.BYTE
REPEAT
.ASCII
.ASCII

ST,FIN,<LEARN YOUR ABC'S>
FIN-ST-1
LENGTH OF 2*STRING
CALL REPEAT MACRO
<LEARN YOUR ABC'S>
/LEARN YOUR ABC'S/
/LEARN YOUR ABC'S/

FIN:

6-5

calls

the

MACROS

An alternative method to pass string arguments in nested macros is to
enclose the macro argument in nested delimiters. In this case the
macro calls in the macro definitions should not have delimiters. Each
time the delimited argument is used in a macro call, the assembler
removes the outermost pair of delimiters before associating it with
the formal argument.
This method is not recommended because it
requires that the programmer know how deeply a macro is nested.
The following macro definition also contains
macro:
LABl:

call

the

.MACRO
.BYTE

CNTRPT2 LAB1,LAB2,STR ARG
LAB2-LAB1-l
LENGTH OF 2*STRING

REPEAT

STR ARG

.ENDM

CNTRPT2

repeat

CALL REPEAT MACRO

LAB2:
Note that the argument in the call to REPEAT is not enclosed in
brackets.

angle

The following example calls the macro CNTRPT2:
BEG:

CNTRPT2 BEG,TERM,<<MIND YOUR P'S AND Q'S>>
LENGTH OF 2*STRING
.BYTE
TERM-BEG-1
REPEAT <MIND YOUR P'S AND Q'S> ; CALL REPEAT MACRO
.ASCII /MIND YOUR P'S AND Q'S/
.ASCII /MIND YOUR P'S AND Q'S/

TERM:
Note that even though the call to REPEAT in the macro definition is
not enclosed in delimiters, the call in the expansion is enclosed in
delimiters because the call to CNTRPT2 contains nested delimiters
around the string argument.

6.1.4

Argument Concatenation

The argument concatenation operator, the apostrophe ('), concatenates
a macro argument with some constant text. Apostrophes can either
precede or follow a formal argument name in the macro source.
If an apostrophe precedes the argument name, the text before the
apostrophe is concatenated with the actual argument when the macro is
expanded. For example, if ARGl is a formal argument associated with
the actual argument TEST, ABCDE'ARGl is expanded to ABCDETEST.
If an apostrophe follows the formal argument name, the actual argument
is concatenated with the text that follows the apostrophe when the
macro is expanded.
For example, if ARG2 is a formal argument
associated with the actual argument MOV, ARG2'L is expanded to MOVL.
Note that
expansion.

the

apostrophe

itself

does

not

appear

the

macro

To concatenate two arguments, separate the two formal arguments with
two successive apostrophes. Two apostrophes are needed because each
concatenation operation discards an apostrophe from the expansion.

6-6

MACROS
An example of a macro definition that uses concatenation follows:
.MACRO CONCAT
INST,SIZE,NUM
TEST'NUM':
INST''SIZE
RO,R'NUM
TEST'NUM'X:
.ENDM
CONCAT
Note that two successive apostrophes are used when
two formal arguments INST and SIZE.

concatenating

the

An example of a macro call and expansion follows:
CON CAT
TESTS: MOVL
TESTSX:

6.1.5

MOV,L,5
RO,RS

Passing Numeric Values of Symbols

When a symbol is specified as an actual argument, the name of the
symbol, not the numeric value of the symbol, is passed to the macro.
However, the value of the symbol can be passed by inserting a
backslash before the symbol in the macro call. The assembler then
passes the characters representing the decimal value of the symbol to
the macro. For example, if the symbol COUNT has a value of 2 and the
actual argument specified is \COUNT, the assembler passes the string
"2" to the macro; it does not pass the name of the symbol, "COUNT".
Passing numeric values of symbols is especially useful with
apostrophe (') concatenation operator for creating new symbols.

the

An example of a macro definition for passing numeric values of symbols
follows:
.MACRO
.ENTRY
.ENDM

TESTDEF,TESTNO,ENTRYMASK=A?AM<>?
TEST'TESTNO,ENTRYMASK
; USES ARG CONCATENATION
TESTDEF

The following example shows a possible call and expansion of the macro
defined above:
COUNT = 2
TESTDEF \COUNT
.ENTRY TEST2,AM<>
COUNT
COUNT + 1
TESTDEF \COUNT,A?AM<R3,R4>?
.ENTRY TEST3,AM<R3,R4>

6.1.6

Created Local Labels

Local labels are often very useful in macros. Although the programmer
can specify local labels in the macro definition, these local labels
might be duplicated elsewhere in the local label block and might thus
cause errors. However, the programmer can use the assembler to create
local labels in the macro expansion which will not conflict with other
local labels. These labels are called created local labels.
Created local labels range from 30000$ through 65535$. Each time the
assembler creates a new local label, it increments the numeric part of
the label name by 1.
Consequently, no user-defined local labels
should be in the range of 30000$ through 65535$.

6-7

MACROS

The programmer specifies a created local label by a question mark (?)
placed in front of the formal argument name. When the macro is
expanded, the assembler creates a new local label if the corresponding
actual argument is blank.
If the corresponding actual argument is
specified, the assembler substitutes the actual argument for the
formal argument. Created local symbols can be used only in the first
31 formal arguments specified in the .MACRO directive.
Created local labels can be associated only with positional actual
arguments;
created local labels cannot be associated with keyword
actual arguments.
The following example is a macro definition specifying a created local
label:
.MACRO
TSTL
BGEQ
MN EGL
.ENDM

Ll:

POSITIVE
ARGl
L"l
ARGl ,ARGl
POSITIVE

ARGl, ?Ll

The following three calls and expansions of the macro defined above
show both created local labels and a user-specified local label:
1.

POSITIVE
TSTL
RO
BGEQ
30000$
MNEGL
RO,RO

30000$:
2.

POSITIVE
COUNT
TSTL
COUNT
BGEQ
30001$
MNEGL
COUNT,COUNT

30001$:
3.

POSITIVE
VALUE,10$
TSTL
VALUE
BGEQ
10$
MNEGL
VALUE,VALUE

10$:

Macro String Operators

6.1.7

The three macro string operators are:
•

%LENGTH

•

%LOCATE

%EXTRACT

These operators perform string manipulations on macro arguments and
ASCII strings.
They can be used only in macros and repeat blocks.
The following sections describe these operators and give their formats
and examples of their use.

6-8

MACROS
0

/oLENGTH

6.1.7.1 %LENGTH Operator - The %LENGTH operator returns the length of
a string. For example, the value of %LENGTH(<ABCDE>) is 5.

Format
%LENGTH(string)

Parameters
string
A macro argument or a delimited string.
The
delimited by angle brackets or a character
circumflex (see Section 6.1.3).

string can be
preceded by a

Examples
Macro definition:
.MACRO CHK'SIZE
ARGl
; MACRO CHECKS IF ARGl
.IF GREATER-EQUAL
%LENGTH(ARG1)-3
; IS BETWEEN 3 AND
.IF LESS THAN
6-%LENGTH(ARG1)
; 6 CHARACTERS LONG
.ERROR ARGUMENT ARGl IS GREATER THAN 6 CHARACTERS
; IF MORE THAN 6
.ENDC
; IF LESS THAN 3
.IF FALSE
ARGUMENT ARGl IS LESS THAN 3 CHARACTERS
.ERROR
; OTHERWISE DO
.ENDC
; NOTHING
.ENDM
CHK SIZE
Macro calls and expansions of the macro defined above:
; SHOULD BE TOO SHORT
CHK SIZE
A
.IF-GREATER EQUAL
1-3 ; IS BETWEEN 3 AND
6-1 ; 6 CHARACTERS LONG
.IF LESS THAN
ARGUMENT A IS GREATER THAN 6 CHARACTERS
.ERROR ; IF MORE THAN 6
.ENDC
.IF FALSE
; IF LESS THAN 3
%MACRO-E-GENERR, Generated ERROR: ARGUMENT A IS LESS THAN 3 CHARACTERS

.ENDC
2.

; OTHERWISE DO

CHK SIZE
ABC
; SHOULD BE OK
.IF-GREATER EQUAL
3-3 ; IS BETWEEN 3 AND
.IF LESS THAN
6-3 ; 6 CHARACTERS LONG
.ERROR
ARGUMENT ABC IS GREATER THAN 6 CHARACTERS
.ENDC
; IF MORE THAN 6
.IF FALSE
; IF LESS THAN 3
.ERROR
ARGUMENT ABC IS LESS THAN 3 CHARACTERS
.ENDC
; OTHERWISE DO

6-9

MACROS

%LOCATE
6.1.7.2 %LOCATE Operator - The %LOCATE operator locates a substring
within a string.
If %LOCATE finds a match of the substring, it
returns the character position of the first character of the match in
the string.
For example, the value of %LOCATE(<D>,<ABCDEF>) is 3.
Note that the first character position of a string is o.
If %LOCATE
does not find a match, it returns a value equal to the length of the
string. For example, the value of %LOCATE(<Z>,<ABCDEF>) is 6.
The %LOCATE operator returns a numeric value that can be used
expression.

any

Format

%LOCATE(stringl,string2 [,symbol] )
Parameters

stringl
A string that specifies the substring.
The substring can be
either a macro argument or a delimited string. The delimiters
can be either angle brackets or a character preceded by a
circumflex.
string2
The string that is searched for the substring. The string can be
either a macro argument or a delimited string. The delimiters
can be either angle brackets or a character preceded by a
circumflex.
symbol
An optional symbol or decimal number that specifies the position
in string2 at which the assembler should start the search. If
this argument is omitted, the assembler starts the search at
position 0 (the beginning of the string). A symbol must be an
absolute symbol that has been previously defined and a number
must be an unsigned decimal number.
Expressions and radix
operators are not allowed.
Example

Macro definition:
.MACRO BIT NAME
ARGl
; CHECKS IF ARGl IS IN LIST
%LOCATE(ARG1,<DELDFWDLTDMOESC>)-15
.IF EQUAL
; IF IT IS NOT PRINT ERROR
.ERROR
ARGl IS AN INVALID BIT NAME
; IF IT IS DO
.ENDC
BIT NAME
; NOTHING
.ENDM

6-10

MACROS

Macro calls and expansions of the macro defined above:
1.

IS IN LIST

BIT NAME
.IF-EQUAL

ESC
12-15

.ERROR
.ENDC

IF IT IS NOT PRINT ERROR
; ESC IS AN INVALID BIT NAME
IF IT IS DO

BIT NAME
• IF-EQUAL

FOO
15-15

%MACRO-E-GENERR, Generated ERROR:

NOT IN LIST
IF IT IS NOT PRINT ERROR
FOO IS AN INVALID BIT NAME

.ENDC

; IF IT IS DO

Note

If the optional symbol is specified, the search begins at the
character position of string2 specified by the symbol. For
example, the value of %LOCATE(<ACE>,<SPACE HOLDER>,5) is 12
because there is no match after the 5th character position.

6.1.7.3 %EXTRACT Operator - The
%EXTRACT
operator
extracts
a
substring from a string. It returns the substring that begins at the
specified position and is the specified length.
For example, the
value of %EXTRACT(2,3,<ABCDEF>) is CDE. Note that the first character
in a string is in position o.
Format

%EXTRACT(symboll,symbol2,string)
Parameters

symboll
A symbol or rlecimal number that specifies the starting position
of the substring. A symbol must be an absolute symbol that has
been previously defined and a number must be an unsigned decimal
number. Expressions and radix operators are not allowed.
symbol2
A symbol or decimal number that specifies the length of the
substring.
A symbol must be an absolute symbol that has been
previously defined and a number must be an unsigned decimal
number. Expressions and radix operators are not allowed.
string
A macro argument or a delimited string.
The
delimited by angle brackets or a character
circumflex.

6-11

string can be
preceded by a

MACROS

Example
Macro definition:
XX

.MACRO RESERVE ARGl
%LOCATE(<=>,ARG1)
.IF EQUAL
XX-%LENGTH(ARG1)
.WARN
; INCORRECT FORMAT FOR MACRO CALL - ARGl
.MEX IT
.ENDC

%EXTRACT(O,XX,ARG1) ::
XX = XX+l
.BLKB
%EXTRACT(XX,3,ARG1)
.ENDM
RESERVE
Macro calls and expansions of the macro defined above:
1.

xx = 6

RESERVE FOOBAR

.IF EQUAL XX-6
%MACRO-W-GENWRN, Generated WARNING:

INCORRECT FORMAT FOR MACRO CALL - FOOBA

.MEXIT
2.

RESERVE LOCATION=l2
8

• IF EQUAL XX-11
.WARN
INCORRECT FORMAT FOR MACRO CALL - LOCATION=l2
.MEX IT
.ENDC
LOCATION::
XX = XX+l
.BLKB

Notes

If the starting position specified is greater than or equal to
the length of the string, %EXTRACT returns a null string (a
string of O characters).
If the length specified is o, %EXTRACT
returns a null string.

6-12

6.2

MACRO DIRECTIVES

The remainder of this chapter describes the macro directives in
detail, showing their formats and giving examples of their use. The
directives are presented in alphabetical order.

.ENDM
.ENDM--END DEFINITION DIRECTIVE
.ENDM terminates the macro definition.
for an example of the use of .ENDM.

See the description of

.MACRO

Format
.ENDM [macro-name]
Parameter
macro-name
The
The name of the macro whose definition is to be terminated.
macro name is optional;
but, if specified, it must match the
The macro name
name defined in the matching .MACRO directive.
should be specified so that the assembler can detect any
improperly nested macro definitions.
Note
If .ENDM is encountered outside a macro definition, the assembler
displays an error message.

.ENDR
.ENDR--END RANGE DIRECTIVE
.ENDR indicates the end of a repeat range.
It must be the final
statement of every indefinite repeat block directive (.IRP and .IRPC)
and every repeat block directive (.REPEAT). See the description of
these directives for examples of the use of .ENDR.
Format
.ENDR

6-13

MACROS

.IRP
.IRP--INDEFINITE REPEAT ARGUMENT DIRECTIVE
.IRP replaces a formal argument with successive actual arguments
specified in an argument list. This replacement process occurs during
the expansion of the indefinite repeat block range.
The .ENDR
directive specifies the end of the range •
• IRP is analogous to a macro definition with only one formal argument.
At each expansion of the repeat block, this formal argument is
replaced with successive elements from the argument list.
The
directive and its range are coded inline within the source program.
This type of macro definition and its range do not require calling the
macro by name, as do other macros described in this chapter •
• IRP can appear either within or outside another macro definition,
indefinite repeat block, or repeat block (see the description of
.REPEAT). The rules for specifying .IRP arguments are the same as
those for specifying macro arguments.
Format
.IRP symbol,<argument list>

range

.ENDR
Parameters
symbol
A formal argument that is successively replaced with
the
specified actual arguments enclosed in angle brackets. If no
formal argument is specified, the assembler displays an error
message.
<argument list>
A list of actual arguments enclosed in angle brackets and used in
expanding the indefinite repeat range. An actual argument can
consist of one or more characters; multiple arguments must be
separated by a legal separator (comma, space, or tab). If no
actual arguments are specified, no action is taken.
range
The block of source text to be repeated once for each occurrence
of an actual argument in the list. The range can contain macro
definitions and repeat ranges. .MEXIT is legal within the range.

6-14

MACROS

Example
Macro definition:
SUBR,Al,A2,A3,A4,A5,A6,A7,A8,A9,Al0
.MACRO CALL SUB
.NARG
COUNT
.!RP
ARG,<Al0,A9,A8,A7,A6,A5,A4,A3,A2,Al>
.IIF NOT BLANK
ARG,
PUSHL ARG
.ENDR
CALLS
; NOTE SUBR IS COUNTED
#<COUNT-1>,SUBR
.ENDM
CALL SUB
Macro call and expansion of the macro defined above:
CALL SUB
TEST,INRES,INTES,UNLIS,OUTCON,#205
.NARG
COUNT
.IRP
ARG,<,,,,,#205,0UTCON,UNLIS,INTES,INRES>
.IIF NOT BLANK ARG,
PUSHL
ARG
.ENDR
• II F NOT BLANK
PUSHL
.IIF NOT-BLANK
PUSHL
.IIF NOT-BLANK
PUSHL
• !IF NOT-BLANK
PUSHL
.IIF NOT-BLANK
,
PUSHL
.IIF NOT-BLANK #205,
PUSHL
#205
.IIF NOT-BLANK OUTCON, PUSHL
OUTCON
.IIF NOT-BLANK UNLIS, PUSHL
UN LIS
.IIF NOT-BLANK INTES, PUSHL
INT ES
.IIF NOT-BLANK INRES, PUSHL
IN RES
CALLS
i<COUNT-1>,TEST
; NOTE TEST IS COUNTED
This example uses the .NARG directive to count the arguments and the
.IIF NOT_BLANK directive (see descriptions of .IF and .IIF in Chapter
5). to determine whether the actual argument is blank.
If the
argument is blank, no binary code is generated.

~-15

MACROS

.IRPC
.IRPC--INDEFINITE REPEAT CHARACTER DIRECTIVE
.IRPC is similar to .IRP except that .IRPC permits single-character
substitution, rather than argument substitution. On each iteration of
the indefinite repeat range, the formal argument is replaced with each
successive character in the specified string. The .ENDR directive
specifies the end of the range •
• IRPC is analogous to a macro definition with only one formal
argument. At each expansion of the repeat block, this formal argument
is replaced with successive characters from the actual argument
string.
The directive and its range are coded inline within the
source program and do not require calling the macro by name, as do
other macros described in this chapter •
• IRPC can appear either within or outside another macro definition,
indefinite repeat block, or repeat block (see description of .REPEAT).
Format

.IRPC

symbol,<string>

range

.ENDR
Parameters

symbol
A formal argument that is successively replaced with
the
specified characters enclosed in angle brackets. If no formal
argument is specified, the assembler displays an error message.
I

<string>
A sequence of characters enclosed in angle brackets and used in
the expansion of the indefinite repeat range. Although the angle
brackets are required only when the string contains separating
characters, their use is recommended for legibility.
range
The block of source text to be repeated once for each occurrence
of a character in the list.
The range can contain macro
definitions and repeat ranges. .MEXIT is legal within the range.

6-16

MACROS

Example
Macro Definition:

.MACRO
.NCHR
.IRPC
HV+"A?CHR?
.ENDR
.ENDM

HASH SYM
HV, <SYMBOL>
CHR, <SYMBOL>

SYMBOL

HASH SYM

Macro call and expansion of the macro defined above:

HV
HV
HV
HV
HV
HV

HASH SYM
<MOVC5>
.NCHR
HV,<MOVC5>
.IRPC
CHR,<MOVC5>
HV+"A?CHR?
.ENDR
HV+"A?M?
HV+"A?O?
HV+"A?V?
HV+"A?C?
HV+"A?5?

This example uses the
.NCHR
characters in actual argument.

directive

fi-17

count

the

number

MACROS

.LIBRARY
.LIBRARY--MACRO LIBRARY DIRECTIVE
.LIBRARY adds a name to the macro library list that is searched
whenever a .MCALL or an undefined opcode is encountered.
The
libraries are searched in the reverse order in which they were
specified to the assembler.
If the programmer omits any information from the macro-library-name
argument, default values are assumed.
The device defaults to the
user's disk; the directory defaults to the user's directory; and the
file type defaults to MLB.
DIGITAL recommends that libraries be specified in the MACRO command
line with the /LIBRARY qualifier rather than with the .LIBRARY
directive. The .LIBRARY directive makes moving files cumbersome.
Format
.LIBRARY macro-library-name
Parameter
macro-library-name
A delimited string that is the
library.

file

specification

Example
.LIBRARY
.LIBRARY
.LIBRARY

MACRO LIBRARY USERM.MLB

/DBl:[TEST]USERM/
?DBl:SYSDEF.MLB?
\CURRENT.MLB\

6-18

macro

MACROS

.MACRO
.MACRO--MACRO DEFINITION DIRECTIVE
.MACRO begins the definition of a macro. It gives the macro name and
a list of formal arguments (see Section 6.1). If the name specified
is the same as the name of a previously defined macro, the previous
definition is deleted and replaced with the new one. The .MACRO
directive is followed by the source text to be included in the macro
expansion. The .ENDM directive specifies the end of the range.
Macro names do not conflict with user-defined symbols.
user-defined symbol can both have the same name.

A macro and

When the assembler encounters a .MACRO directive, it adds the macro
name to its macro name table and stores the source text of the macro
(up to the matching .ENDM directive).
No other processing occurs
until the macro is expanded.
The symbols in the formal argument list are associated with the macro
name and are limited to the scope of the definition of that macro.
For this reason, the symbols that appear in the formal argument list
can also appear elsewhere in the program.

Format
.MACRO macro-name

[formal-argument-list]

range

.ENDM [macro name]

Parameters
macro-name
The name of the macro to be defined;
symbol up to 31 characters long.

this name can be any

legal

formal-argument-list
The symbols, separated by commas, to be replaced
arguments in the macro call.

range
The source text to be included in the macro expansion.

n-19

the

actual

MACROS
Example
Macro definition:
.MACRO
.PSECT

USERDEF
DEFS,ABS

MYSYM= 5
HIVAL= "XFFF123
LOWVAL= 0
.PSECT RWDATA,NOEXE,LONG
TABLE:
.BLKL
100
LIST:
.BLKB
10
.MACRO USERDEF
.ENDM
USERDEF
.ENDM
USERDEF

REDEFINE IT TO NULL

Macro calls and expansions of the macro defined above:
USERDF
.PSECT

SHOULD EXPAND DATA
DEFS,ABS

MYSYM= 5
HIVAL= "XFFF123
LOWVAL= 0
.PSECT RWDATA,NOEXE,LONG
TABLE: .BLKL
100
LIST:
.BLKB
10
.MACRO USERDEF
USERDEF
.ENDM
USERDF

REDEFINE IT TO NULL

SHOULD EXPAND NOTHING

In this example, when the macro is called the first time it defines
some symbols and data storage areas and then redefines itself. When
the macro is called a second time, the macro expansion contains no
source text.
Notes
1.

If a macro has the same name as a VAX-11 opcode, the macro is
used instead of the instruction.
This feature allows a
programmer to temporarily redefine an opcode.

If a macro has the same name as a VAX-11 opcode and is in a
macro library, the .MCALL directive must be used to define
the macro. Otherwise, because the symbol is already defined
(as the opcode), the assembler will not search the macro
libraries.

The programmer can redefine a macro with new source text
during assembly by specifying a second .MACRO directive with
the same name. Including a second .MACRO directive within
the original macro definition causes the first macro call to
redefine the macro. This is useful when a macro performs
initialization
or
defines symbols;
that is, when an
operation is performed only once. The macro redefinition can
eliminate unneeded source text in a macro or it can delete
the entire macro. The .MDELETE directive provides another
way to delete macros.

6-20

MACROS

.MCALL
.MCALL--MACRO CALL DIRECTIVE

.MCALL specifies the names of the system and/or user-defined macros
that are required to assemble the source program but are not defined
in the source file.
If any named macro is not.found upon completion of the search (that
is, if the macro is not defined in any of the macro libraries), the
assembler displays an error message.
Format

.MCALL macro-name-list
Parameter

macro-name-list
A list of macros to be defined for this assembly.
be separated by commas.

The names must

Example

.MCALL

INSQUE

SUBSTITUTE MACRO IN
LIBRARY FOR INSQUE
INSTRUCTION

Note

.MCALL is provided for compatibility with MACR0-11;
DIGITAL
recommends that it not be used.
When VAX-11 MACRO finds an
unknown symbol in the opcode field, it automatically searches all
macro libraries.
If it finds the symbol in a library, it uses
the macro definition and expands the macro reference. If VAX-11
MACRO does not find the unknown symbol in the library, it
displays an error message. There is one exception for which
.MCALL must be used: when a macro has the same name as an opcode
(see description of .MACRO).

6-21

MACROS

.MDELETE
.MDELETE--MACRO DELETION DIRECTIVE
.MDELETE deletes the definitions of specified macros. The number of
macros actually deleted is printed in the assembly listing on the same
line as the .MDELETE directive •
• MDELETE completely deletes the macro, freeing memory as necessary,
whereas
the
technique of macro redefinition explained in the
description of .MACRO merely redefines the macro.
Format
.MDELETE macro-name-list
Parameter
macro-name-list
A list of macros whose definitions are to be deleted.
must be separated by commas.
Example
.MDELETE

USERDEF,$SSDEF,ALTR

6-22

The

names

MACROS

.MEXIT
.MEXIT--MACRO EXIT DIRECTIVE

.MEXIT terminates a macro expansion before the end of the macro.
Termination is the same as if .ENDM was encountered. The directive
can also be used within repeat blocks.
.MEXIT is most useful in
conditional expansion of macros because it bypasses the complexities
of nested conditional directives and alternate assembly paths.
Format

.MEX IT
Example

.MACRO

POLO

• IF EQ

N,A,B
START CONDITIONAL ASSEMBLY BLOCK •

• MEX IT
• ENDC
.ENDM

TERMINATE MACRO EXPANSION •
END CONDITIONAL ASSEMBLY BLOCK •
POLO

; NORMAL END OF MACRO.

In this example, if the actual argument for the formal argument N
equals O, the conditional block would be assembled, and the macro
expansion would be terminated by .MEXIT.
Notes

When .MEXIT occurs in a repeat block,
the
assembler
terminates the current repetition of the range and suppresses
further expansion of the repeat range.

When macros or repeat blocks are nested, .MEXIT exits to
next higher level of expansion.

If .MEXIT occurs outside a macro definition or
block, the assembler displays an error message.

6-23

the

repeat

MACROS

.NARG
.NARG--NUMBER OF ARGUMENTS DIRECTIVE

.NARG determines the number of arguments in the current macro call •
• NARG counts all the positional arguments specified in the macro call,
including null arguments {specified by adjacent commas). The value
assigned to the specified symbol does not include either any keyword
arguments or any formal arguments that have default values.
Format

.NARG

symbol

Parameter

symbol
A symbol that is assigned a
arguments in the macro call.

value

equal

the

number

Example

Macro definition:
.MACRO
.NARG
.WORD
.ENDM

CNT ARG Al,A2,A3,A4,A5,A6,A7,A8,A9=DEF9,Al0=DEF10
COUNTER
; COUNTER IS SET TO NO. OF ARGS
COUNTER
; STORE VALUE OF COUNTER
CNT ARG

Macro calls and expansions of the macro defined above:
1.

CNT ARG TEST,FIND,ANS
.NARG
COUNTER
COUNTER
.WORD

COUNTER WILL = 3
COUNTER IS SET TO NO. OF ARGS
STORE VALUE OF COUNTER

CNT ARG
COUNTER
.NARG
COUNTER
.WORD

COUNTER WILL = 0
COUNTER IS SET TO NO. OF ARGS
STORE VALUE OF COUNTER

CNT ARG TEST,A2=SYMB2,A3=SY3
.NARG
COUNTER
COUNTER
.WORD

COUNTER WILL = 1
COUNTER rs SET TO NO. OF ARGS
STORE VALUE OF COUNTER
KEYWORD ARGUMENTS ARE NOT CO UN TE

CNT ARG ,SYMBL,,
.NARG
COUNTER
COUNTER
.WORD

COUNTER WILL = 3
COUNTER IS SET TO NO. OF ARGS
STORE VALUE OF COUNTER
NULL ARGUMENTS ARE COUNTED

Note

If .NARG appears outside of
message.

6-24

macro,

the

assembler

displays

MACROS

.NCHR
.NCHR--NUMBER OF CHARACTERS DIRECTIVE
.NCHR determines the number of characters in a specified character
string.
It can appear anywhere in a VAX-11 MACRO program and is
useful in calculating the length of macro arguments.
Format
.NCHR

symbol,<string>

Parameters
symbol
A symbol that is assigned a value equal to
characters in the specified character string.

the

number

<string>
A sequence of printable characters. The character string must be
delimited by angle brackets or a character preceded by a
circumflex only if the specified character string contains a
legal separator (comma, space, and/or tab) or a semicolon.
Example
Macro definition:
.MACRO
.NCHR
.WORD
.ASCII
.ENDM

DEFINE MACRO
ASSIGN VALUE TO CHRCNT
STORE VALUE
STORE CHARACTERS
FINISH

CHAR
MESS
CHRCNT,<MESS>
CHRCNT
/MESS/
CHAR

Macro calls and expansions of the macro defined above:
CHRCNT WILL = 5
ASSIGN VALUE TO CHRCNT
STORE VALUE
STORE CHARACTERS

CHAR
.NCHR
.WORD
.ASCII

<HELLO>
CHRCNT,<HELLO>
CHRCNT
/HELLO/

CHAR
.NCHR
.WORD
.ASCII

<14, 75.39 4>
CHRCNT,<14, 75.39
CHRCNT
/14, 75.39 4/

6-25

CHRCNT WILL= 12(DEC)
ASSIGN VALUE TO CHRCNT
STORE VALUE
STORE CHARACTERS

MACROS

.NTYPE
.NTYPE--OPERAND TYPE DIRECTIVE
.NTYPE determines the addressing mode of the specified operand.
The value of the symbol is set to the specified addressing mode.
In
most cases, an 8-bit (1-byte) value is returned. Bits O through 3
specify the register associated with the mode, and bits 4 through 7
specify
the
addressing
mode.
To provide concise addressing
information, the mode bits 4 through 7 are not exactly the same as the
numeric
value of the addressing mode described in Table 4-1.
Specifically, literal mode is indicated by a O in bits 4 through 7
instead of the values 0 through 3 described in Table 4-1. Mode 1
indicates an immediate mode operand, mode 2 indicates an absolute mode
operand, and mode 3 indicates a general mode operand.
For indexed addressing mode, a 16-bit (2-byte) value is returned. The
high-order byte contains the addressing mode of the base operand
specifier and the low-order byte contains the addressing mode of the
primary operand (the index register).
See the VAX-11 Architecture Handbook and Chapter 4 of this manual
more information on-addressing modes.

for

Format
.NTYPE

symbol,operand

Parameter
symbol
Any legal VAX-11 MACRO symbol. This symbol is assigned a value
equal to the 8- or 16-bit addressing mode of the operand argument
that follows.
operand
Any legal address expression, as used
argument is specified, 0 is assumed.

6-26

with

opcode.

MACROS

Example
Macro Definition:
THE FOLLOWING MACRO IS USED TO PUSH AN ADDRESS ON THE STACK.
IT CHECKS
THE OPERAND TYPE (BY USING .NTYPE) TO DETERMINE IF THE OPERAND IS AN
ADDRESS AND, IF NOT, THE MACRO SIMPLY PUSHES THE ARGUMENT ON THE STACK
AND GENERATES A WARNING MESSAGE •

ERR

• MACRO PUSHADR ADDR
.NTYPE A,ADDR
A@-4&"'XF
.IF IDENTICAL O,<ADDR>
PUSHL
#0
.MEXIT
.ENDC

ASSIGNS OPERAND TYPE TO A
ISOLATE ADDRESSING MODE
IS ARGUMENT EXACTLY 0
STACK ZERO
EXIT FROM MACRO

.IIF LESS EQUAL A-1,
ERR=l
.IIF EQUAL A-5,
ERR=l
.IF EQUAL ERR
PUSHAL ADDR
.IFF
PUSHL
ADDR
.WARN
; ADDR IS NOT AN ADDRESS
.ENDC
.ENDM
PUSHADR

ERR TELLS IF MODE IS ADDRESS
ERR = 0 FOR ADDRESS, 1 WHEN NOT
IS MODE NOT LITERAL OR IMMEDIATE
IS MODE NOT REGISTER
IS MODE ADDRESS?
YES, STACK ADDRESS
NO
THEN STACK OPERAND & WARN

Macro calls and expansions of the macro defined above:
1.

PUSHADR (RO)
PUS HAL
(RO)

VALID ARGUMENT
YES, STACK ADDRESS

PUSHADR (Rl) [R4]
PUS HAL
(Rl) [R4]

VALID ARGUMENT
YES, STACK ADDRESS

PUSHADR 0
PUSHL
#0

IS ZERO
STACK ZERO

PUSHADR #1
NOT AN ADDRESS
PUSHL
; THEN STACK OPERAND & WARN
#1
%MACRO-W-GENWRN, Generated WARNING: #1 IS NOT AN ADDRESS
5.

PUSHADR RO
NOT AN ADDRESS
PUSHL
RO
; THEN STACK OPERAND & WARN
%MACRO-W-GENWRN, Generated WARNING: RO IS NOT AN ADDRESS
Note that to save space, this example is listed as it would appear if
.SHOW BINARY, not
.SHOW EXPANSIONS, was specified in the source
program.

6-27

MACROS

.REPEAT
.REPEAT--REPEAT BLOCK DIRECTIVE
.REPEAT repeats a block of code, a specified number of times,
inline
with other source code. The .ENDR directive specifies the end of the
range.
Format
.REPEAT expression

range

.ENDR

Parameters
expression
An expression whose value controls the number of times the range
is to be assembled within the program. When the expression is
less than or equal to O, the repeat block is not assembled.
The
expression must not contain any undefined symbols and must be an
absolute expression (see Section 3.5).
range
The source text to be repeated the number of times specified by
the value of the expression. The repeat block can contain macro
definitions, indefinite repeat blocks, or other repeat blocks •
• MEXIT is legal within the range.

Example
Macro definition:
.MACRO COPIES STRING,NUM
• REPEAT -NUM
.ASCII /STRING/
.ENDR
.BYTE
0
• ENDM
COPIES
Macro calls and expansions of the macro defined above:
1.

COPIES <ABCDEF>,5
.REPEAT 5
.ASCII /ABCDEF/
.ENDR
.ASCII /ABCDEF/
.ASCII /ABCDEF/
.ASCII /ABCDEF/
.ASCII /ABCDEF/
.ASCII /ABCDEF/
.BYTE
0

6-28

MACROS

2.
VARB

COPIES <HOW MANY
.REPEAT 3
.ASCII /HOW MANY
.ENDR
.ASCII /HOW MANY
.ASCII /HOW MANY
.ASCII /HOW MANY
.BYTE
0

TIMES>,\VARB
TIMES/
TIMES/
TIMES/
TIMES/

Note
The alternate form of .REPEAT is .REPT.

6-29

APPENDIX A
ASCII CHARACTER SET

Table A-1 lists the ASCII characters
each.

and

the

hexadecimal

code

Table A-1
Hexadecimal/ASCII Conversion
HEX
Code

ASCII
Char.

HEX
Code

ASCII
Char.

HEX
Code

00
01
02
03
04
OS
06
07
08
09
OA
OB

NUL
SOH
STX
ETX
EQT
ENQ
ACK
BEL
BS
HT
LF
VT
FF
CR

20
21
22
23
24
2S
26
27
28
29
2A
2B
2C
2D
2E
2F
30
31
32
33
34
3S
36
37
38
39
3A
3i3
3C
30
3E
3F

40
41
42
43
44
4S
46
47
48
49
4A
4B
4C
4D
4E
4F

OD
OE
OF
10
11
12
13
14
lS
16
17
18
19
lA
lB

lC
lD

lE
lF

SI
DLE
DCl
DC2
DC3
DC4
NAK
SYN
ETB
CAN
EM
SUB
ESC
FS
GS
RS

#
$
%
&
I

(
)

0
1
2
3
4

6
7
8
9
:
;

<
=

>
?

A-1

ASCII
Char.

HEX
Code

ASCII
Char.

A
B

61
62
63
64
6S
66
r,7
68
69
6A
6B
6C
6D
6E
6F
70
71
72
73
74
7S
76
77
78
79
7A
7B
7C
7D
7E
7F

a
b
c
d
e
f

D
E
F
G
H
I
J
K

L
M

N
0

Sl
S2
S3
54
SS
S6
57
SS
S9
SA
SB
SC
SD
SE
SF

Q
R

v
w
x
y

z
[

\
]

h
i
j
k

1
m
n
0

p
q

r
s
t
u

w
x
y

DEL

for

APPENDIX B
VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY

B.l

ASSEMBLER DIRECTIVES

The following table summarizes the VAX-11 MACRO assembler directives.
Table B-1
Assembler Directives
Format

Operation

.ADDRESS address-list

Stores successive longwords of
address data

.ALIGN keyword [,expression]

Aligns the location counter to
the boundary specified by the
keyword

.ALIGN integer [,expression]

Aligns location counter to the
boundary specified by (2~integer)

.ASCIC string

Stores the ASCII string string
(enclosed in delimiters),
preceded by a count byte

.ASCID string

Stores the ASCII (enclosed in
delimiters), preceded by a string
descriptor

.ASCII string

Stores the ASCII string (enclosed
in delimiters)

.ASCIZ string

Stores the ASCII string (enclosed
in delimiters) followed by a 0
byte.

.BLKA expression

Reserves longwords of address
data

.BLKB expression

Reserves bytes for data

.BLKD expression

Reserves quadwords for
double-precision, floating-point
data
(continued on next page)

B-1

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
Table B-1 (Cont.)
Assembler Directives
Operation

Format
.BLKF expression

Reserves longwords for
single-precision, floating-point
data

.BLKG expression

Reserves quadwords for
floating-point data

.BLKH expression

Reserves octawords for
extended-precision floating-point
data

.BLKL expression

Reserves longwords for data

.BLKO expression

Reserves octawords for data

.BLKQ expression

Reserves quadwords for data

.BLKW expression

Reserves words for data

.BYTE expression-list

Generates successive bytes of
data; each byte contains the
value of the specified expression

.CROSS

Enables cross-referencing of all
symbols

.CROSS symbol-list

Cross-references specified
symbols

.DEBUG symbol-list

Makes symbol names known to the
debugger

.DEFAULT DISPLACEMENT, keyword

Specifies the default
displacement length for the
relative addressing modes

.D FLOATING literal-list

Generates 8-byte,
double-precision, floating-point
data

.DISABLE argument-list

Disables function(s) specified in
argument-Ii st

.DOUBLE literal-list

Equivalent to .D_FLOATING

.DSABL argument-list

Equivalent to .DISABLE

.ENABL argument-list

Equivalent to .ENABLE

.ENABLE argument-list

Enables function(s) specified in
argument-list

.END [symbol]

Indicates logical end of source
program; optional symbol
specifies transfer address
(continued on next page)

B-2

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
Table B-1 (Cont.)
Assembler Directives
Format

Operation

.ENDC

Indicates end of conditional
assembly block

.ENDM [macro-name]

Indicates end of macro definition

.ENDR

Indicates end of repeat block

.ENTRY symbol
~ERROR

[,expression]

[expression]

;comment

Procedure entry directive
Displays specified error message

.EVEN

Ensures that the current location
counter has an even value (adds 1
if it is odd)

.EXTERNAL symbol-list

Indicates specified symbols are
externally defined

.EXTRN symbol-list

Equivalent to .EXTERNAL

.F FLOATING literal-list

Generates 4-byte,
single-precision, floating point
data

.FLOAT literal-list

Equivalent to .F_FLOATING

.G FLOATING literal-list

Generates 8-byte G_floating-point
data

.GLOBAL symbol-list

Indicates specified symbols are
global symbols

.GLOBL

Equivalent to .GLOBAL

.H FLOATING literal-list

Generates 16-byte, extended
precision H_floating-point data

.!DENT string

Provides means of labeling object
module with additional data

.IF condition argument(s)

Begins a conditional assembly
block of source code which is
included in the assembly only if
the stated condition is met with
respect to the argument(s)
specified

.IFF

Equivalent to .IF FALSE

.IF FALSE

Appears only within a conditional
assembly block;
begins block of
code to be assembled if the
original condition tests false

.IFT

Equivalent to .IF TRUE
(continued on next page)

B-3

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
Table B-1 (Cont.)
Assembler Directives
Format

Operation

.IFTF

Equivalent to .IF_TRUE_FALSE

.IF TRUE

Appears only within a conditional
assembly block; begins block of
code to be assembled if the
original condition tests true

.IF TRUE FALSE

Appears only within a conditional
assembly block; begins block of
code to be assembled
unconditionally

.IIF condition argument(s),
statement

Acts as a
1-line conditional
assembly block where the
condition is tested for the
argument specified; the
statement is assembled only if
the condition tests true

.IRP sym<argument list>

Replaces a formal argument with
successive actual arguments
specified in an argument list

.IRPC sym,<string>

Replaces a formal argument with
successive single characters
specified in string

.LIBRARY macro-library-name

Specifies a macro library

.LIST [argument-list]

Equivalent to .SHOW

.LONG expression-list

Generates successive longwords of
data; each longword contains the
value of the specified
expression •

• MACRO macro-name,argument-list

Begins a macro definition

.MASK symbol [,expression]

Reserves a word for and copies a
register save mask

.MCALL macro-name-list

Specifies the system and/or
user-defined macros in libraries
that are required to assemble the
source program

.MDELETE macro-name-list

Deletes from memory the macro
definitions of the macros in the
list

.MEXIT

Exits from the expansion of a
macro before the end of the macro
is encountered
(continued on next page)

B-4

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY

Table B-1 (Cont.)
Assembler Directives
Format

Operation

.NARG symbol

Determines the number of
arguments in the current macro
call

.NCHR symbol,<string>

Determines the number of
characters in a specified
character string

.NLIST [argument-list]

Equivalent to .NOSHOW

.NOCROSS

Disables cross-referencing of all
symbols

.NOCROSS symbol-list

Disables cross-referencing of
specified symbols

.NOSHOW

Decrements listing level count

.NOSHOW argument-list

Controls listing of macros and
conditional assembly blocks

.NTYPE symbol,operand

Can appear only within a macro
definition; equates the symbol
to the addressing mode of the
specified operand

.OCTA literal

Stores 16 bytes of data

.OCTA symbol

Stores 16 bytes of data

.ODD

Ensures that the current location
counter has an odd value (adds 1
if it is even)

.OPDEF opcode value,
operand-descriptor-list

Defines an opcode and its
operand list

.PACKED decimal-string [,symbol] Generates packed decimal data, 2
digits per byte
.PAGE

Causes the assembly listing to
skip to the top of the next page,
and to increment the page count

.PRINT [expression] ;comment

Displays the specified message

.PSECT

Begins or resumes the blank
program section

.PSECT section-name
argument-list

Begins or resumes a user-defined
program section
(continued on next page)

B-5

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
Table B-1 (Cont.)
Assembler Directives
Format

Operation

• QUAD Ii teral

Stores 8 bytes of data

.QUAD symbol

Stores 8 bytes of data

.REFl operand

Generates byte operand

.REF2 operand

Generates word operand

.REF4 operand

Generates longword operand

.REF8 operand

Generates quadword operand

.REF16 operand

Generates octaword operand

.REPEAT expression

Begins a repeat
section of code
.ENDR directive
number of times
expression

.REPT

Equivalent to .REPEAT

.RESTORE

Equivalent to .RESTORE_PSECT

.RESTORE PSECT

Restores program section context
from the program section context
stack

.SAVE [LOCAL_BLOCK]

Equivalent to .SAVE_PSECT

.SAVE_PSECT [LOCAL_BLOCK]

Saves current program section
context on the program section
context stack

.SBTTL comment-string

Equivalent to .SUBTITLE

.SHOW

Increments listing level count

.SHOW argument-list

Controls listing of macros and
conditional assembly blocks

.SIGNED_BYTE expression-list

Stores successive bytes (8 bits)
of signed data

.SIGNED WORD expression-list

Stores successive words (16 bits)
of signed data

.SUBTITLE comment-string

Causes the specified string to be
printed as part of the assembly
listing page header; the string
component of each .SUBTITLE is
collected into a table of
contents at the beginning of the
assembly listing

block; the
up to the next
is repeated the
specified by the

(continued on next page)

B-6

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
Table B-1 (Cont.)
Assembler Directives
Format

Operation

.TITLE module-name
comment-string

Assigns the first 15 characters in
the string as an object module
name and causes the string to
appear on each page of the
assembly listing

.TRANSFER symbol

Directs the linker to redefine
the value of the global symbol
for use in a shareable image

.WARN [expression] ;comment

Displays specified warning
message

.WEAK symbol-list

Indicates that each of the listed
symbols has the weak attribute

.WORD expression-list

Generates successive words of
data; each word contains the
value of the corresponding
specified expression

SPECIAL CHARACTERS

B.2

The following table summarizes the VAX-11 MACRO special characters.
Table B-2
Special Characters Used in VAX-11 MACRO Statements
Character

Character Name

Function(s)

Underline

Character in symbol names

Dollar sign

Character in symbol names

Period

Character in symbol names,
current location counter, and
decimal point

Colon

Label terminator

Equal sign

Direct assignment operator and
macro keyword argument terminator

Tab

Field terminator

Space

Field terminator

Number sign

Immediate addressing mode
indicator

(continued on next page)

B-7

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
Table B-2 (Cont.)
Special Characters Used in VAX-11 MACRO Statements
Character

Character Name

Function(s)

At sign

Def erred addressing mode
indicator and arithmetic shift
operator

Comma

Field, operand, and item
separator

Semicolon

Comment field indicator

Plus sign

Autoincrement addressing mode
indicator, unary plus operator,
and arithmetic addition operator

Minus sign

Autodecrement addressing mode
indicator, unary minus operator,
arithmetic subtraction operator,
and line continuation indicator

Asterisk

Arithmetic multiplication
operator

Slash

Arithmetic division operator

Ampersand

Logi~al

Exclamation
point

Logical inclusive OR operator

Backslash

Logical exclusive OR and numeric
conversion indicator in macro
arguments

...

Circumflex

Unary operator indicator and
macro argument delimiter

Square brackets

Index addressing mode and repeat
count indicators

()

Parentheses

Angle brackets

Argument or expression grouping
delimiters

Question mark

Created label indicator in macro
arguments

Apostrophe

Macro argument concatenation
indicator

Percent sign

Macro string operators

B-8

AND operator

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
B.3

OPERATORS

B.3.1

Unary Operators

The following table summarizes the VAX-11 MACRO unary operators.
Table B-3
Unary Operators
Unary
Operator

Operator
Name

Plus sign

Results in the positive
value of A •(default)

Minus sign

-A

Results in the negative
(2's complement) value
of A

Binary

"'BllOOOlll

Specifies that 11000111
is a binary number

"'o

Decimal

"'0127

Specifies that 127 is a
decimal number

"'o

Octal

"'034

Specifies that 34 is an
octal number

"'x

Hexadecimal

"'XFCF9

Specifies that FCF9 is
a hexadecimal number

ASCII

"'A/ABC/

Produces an ASCII
string; the characters
between the matching
delimiters are
converted to ASCII
representation

"'M<R3,R4,R5>

Specifies the registers
R3, R4, and RS in the
register mask

Floating point

"'F3 .O

Specifies that 3.0 is a
floating-point number

Complement

"'C24

Produces the l's
complement value of 24
(decimal)

"'c

Example

B-9

Effect

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
B.3.2

Binary Operators

The following table summarizes the VAX-11 MACRO binary operators.
Table B-4
Binary Operators
...

Binary
Operator

Operator
Name

Example

Plus sign

A+B

Addition

Minus sign

A-B

Subtraction

Asterisk

A*B

Multiplication

Slash

A/B

Division

At sign

A@B

Arithmetic Shift

Ampersand

A&B

Logical AND

Exclamation point

A!B

Logical inclusive OR

Backslash

A\B

Logical exclusive OR

------.
B.3.3

Operation

,..,.,.._.

Macro String Operators

The following table summarizes the macro
operators can be used only in macros.

string

operators.

These

Table B-5
Macro String Operators
-·---····-----------

Format

-----------------Function

%LENGTH(string)

Returns the length of the
string

%LOCATE(stringl,string2[,symbol])

Locates the substring
stringl within string2
starting the search at the
character position specified
by symbol

%EXTRACT(symboll,symbol2,string)

Extracts a substring from
string that begins at
character position specified
by symboll and has a length
specified by symbol2

B-10

VAX-11 MACRO ASSEMBLER DIRECTIVES AND LANGUAGE SUMMARY
B.4

ADDRESSING MODES

The following table summarizes the VAX-11 MACRO addressing modes.
Table B-6
Addressing Modes

Type

Addressing
Mode

Hexadecimal
Value

Formatl

General
Register

Indexable?

Description

-1

~""-

(Rn)

Yes

Auto increment

(Rn)+

Register contains the addr ess of the
operand;
the processor
increments the register co ntents
by the size of the operand data
type

Yes

Auto increment
Deferred

@(Rn)+

Yes

Autodecrement

-(Rn)

The processor decrements t he
register contents by the s lZe
of the operand data type;
the
register then contains the
address of the operand

Yes

Displacement

dis (Rn)
BAdis(Rn)
WAdis(Rn)
LAdis(Rn)

The sum of the contents of the
register and the displacem ent is
the address of the operand, BA,
WA 1 and LA indicate byte, word,
and longword displacement,
respectively

Yes

The sum of the contents of the
register and the displacem ent is
the address of the operand
address; BA, WA, and LA
indicate byte, word, and
longword displacement,
respectively

Yes

The literal specified is t he
the operand; the literal is
stored as a short literal

The address specified is t he
address of the operand; t he
address specified is store d as a
displacement from PC; BA, WA,
and LA indicate byte, word , and
longword displacement,
respectively

Yes

The address specified is t he address
of the operand address; t he address
specified is stored as a
displacement from PC; BA, WA,
and LA indicate byte, word , and
longword displacement,
respectively

Yes

The address specified is t he address
of the operand; the addre SS
specified is stored as an
absolute virtual address ( not as
a displacement)

Yes

The literal specified is t he
operand; the literal is s to red
as a byte, word, longword, or
quadword

Displacement
Def erred

General
Register
(Cont.)

Literal

Program
Counter

Relative

Relative
Deferred

@dis(Rn)
@BAdis(Rn)
@WAdis(Rn)
@LAdis(Rn)

D
F

#literal
SA#literal

0-3

address
BA address
WA address
LAaddress

@address
@BA address
@.WA address
@.LAaddress

D
F

Absolute

@#address

Immediate

#literal
IA#literal

---

•------

-----·~--·------·--~

(continued on next page)

B-ll

Table B-6 (Cont.)
Addressing Modes

Addressing
Mode

Format!

General

GA address

Index

base-mode[Rx]

Branch

address

Type

.__, -------·"·---1

Hexadecimal
Value

Description

Indexable?

The address specified is the
address of the operand; if the
address is defined as
relocatable, the linker stores
the address as a displacement
from PC; if the address is
defined as an absolute virtual
address, the linker stores the
address as an absolute value

Yes

The address specified is the
operand; this address is stored
as a displacement to PC; branch
mode can only be used with the
branch instructions

1. Key:

Any general register RO through Rl2.
register can be used in place of Rn.

Note that the AP, FP, or SP

Any general register RO through Rl2. Note that the AP, FP, or SP
register can be used in place of Rx. Rx cannot be the same as
the Rn specified in the base-mode for certain base modes (see
Section 4.3).
dis

An expression specifying a displacement.
address
An expression specifying an address.
literal
An expression, an integer constant, or a floating-point constant.

B-12

APPENDIX C
PERMANENT SYMBOL TABLE

The permanent symbol table (PST) contains the symbols that VAX-11
MACRO automatically recognizes. These symbols consist of both opcodes
and assembler directives. Sections C.l and C.2 below present the
opcodes
(instruction set) in alphabetical and numerical order,
respectively. Appendix B (in Section B.l) presents the assembler
directives.
The VAX-11 Architecture Handbook provides a
the instruction set.

C.l

6F
4F
4FFD
6FFD
Fl
3D
58

80
81

60
61
40
41
40FD
41FD
60FD
61FD
Cl
20
21

AO
Al
DB
F3
F2
78
F8
79

description

OPCODES (ALPHABETIC ORDER)

Hexadecimal
Value

detailed

Mnemonic

Functional Name

ACBB
ACBD
ACBF
ACBG
ACBH
ACBL
ACBW
ADAWI
ADDB2
ADDB3

Add compare and branch byte
Add compare and branch D floating
Add compare and branch F-floating
Add compare and branch G-floating
Add compare and branch H-floating
Add compare and branch long
Add compare and branch word
Add aligned word interlocked
Add byte 2 operand
Add byte 3 operand

ADDD2
ADDD3
ADDF2
ADDF3
ADDG2
ADDG3
ADDH2
ADDH3
ADDL2
ADDL3
ADDP4
ADDP6

Add D-floating 2 operand
Add D-f loating 3 operand
Add F floating 2 operand
Add F-f loating 3 operand
Add G-f loating 2 operand
Add G-floating 3 operand
Add H-floating 2 operand
Add H-floating 3 operand
Add long 2 operand
Add long 3 operand
Add packed 4 operand
Add packed 6 operand

ADDW2
ADDW3
ADWC
AOBLEQ
AOBLSS
ASHL
ASHP
ASHQ

Add word 2 opetand
Add word 3 operand
Add with carry
Add one and branch on less or equal
Add one and branch on less
Arithmetic shift long
Arithmetic shift and round packed
Arithmetic shift quad

C-1

PERMANENT SYMBOL TABLE
Hexadecimal
Value
El
ES
E7
E3
EO
E4
E2
E6

lE
IF
13

lB
IE
14
IA
BA

BB
CA
CB
89

AA
AB

BB
B9
CB

BB
AB
A9
93
03

83
E9

EB
15
18
19

lF
12
12
03

31
10
30

ID
FA
FB
8F

CF
AF

Mnemonic

Functional Name

BBC
BBCC
BBC CI
BBCS
BBS
BBSC
BBSS
BBS SI

Branch on bit clear
Branch on bit clear and clear
Branch on bit clear and clear interlocked
Branch on bit clear and set
Branch on bit set
Branch on bit set and clear
Branch on bit set and set
Branch on bit set and set interlocked

BCC
BCS
BEQL
BEQLU
BGEQ
BGEQU
BGTR
BGTRU

Branch on carry clear
Branch on carry set
Branch on equal
Branch on equal unsigned
Branch on greater or equal
Branch on greater or equal unsigned
Branch on greater
Branch on greater unsigned

BICB2
BICB3
BICL2
BICL3
BICPSW
BICW2
BICW3
BISB2

Bit clear byte 2 operand
Bit clear byte 3 operand
Bit clear long 2 operand
Bit clear long 3 operand
Bit clear program status word
Bit clear word 2 operand
Bit clear word 3 operand
Bit set byte 2 operand

BISB3
BISL2
BISL3
BISPSW
BISW2
BISW3
BITS
BITL

Bit set byte 3 operand
Bit set long 2 operand
Bit set long 3 operand
Bit set program status word
Bit set word 2 operand
Bit set word 3 operand
Bit test byte
Bit test long

BITW
BLBC
BLBS
BLEQ
BLEQU
BLSS
BLSSU
BNEQ

Bit test word
Branch on low bit clear
Branch on low bit set
Branch on less or equal
Branch on less or equal unsigned
Branch on less
Branch on less unsigned
Branch on not equal

BNEQU
BPT
BRB
BRW
BSBB
BSBW
BVC
BVS

Branch on not equal unsigned
Break point trap
Branch with byte displacement
Branch with word displacement
Branch to subroutine with byte displacement
Branch to subroutine with word displacement
Branch on overflow clear
Branch on overflow set

CAL LG
CALLS
CASES
CASEL
CASEW

Call with general argument list
Call with stack
Case byte
Case long
Case word

C-2

PERMANENT SYMBOL TABLE

Hexadecimal
Value

Mnemonic

Functional Name

BD
BC
BE
BF
94

CHME
CHMK
CHMS
CHMU
CLRB

Change mode
Change mode
Change mode
Change mode
Clear byte

7C
DF
7C
7CFD
D4
7CFD
7C
B4
91

CLRD
CLRF
CLRG
CLRH
CLRL
CLRO
CLRQ
CLRW
CMPB

Clear D floating
Clear F-floating
Clear G-floating
Clear H-floating
Clear long
Clear octa
Clear quad
Clear word
Compare byte

29
2D

CMPC3
CMPC5
CMPD
CMPF
CMPG
CMPH
CMPL
CMPP3
CMPP4
CMPV

Compare character 3 operand
Compare character 5 operand
Compare D floating
Compare F-floating
Compare G-f loating
Compare H-floating
Compare long
Compare packed 3 operand
Compare packed 4 operand
Compare field

6C
4C
4CFD
6CFD
98
99
68

CMPW
CMPZV
CRC
CVTBD
CVTBF
CVTBG
CVTBH
CVTBL
CVTBW
CVTDB

Compare word
Compare zero-extended field
Calculate cyclic redundancy check
Convert byte to D floating
Convert byte to F-floating
Convert byte to G-f loating
Convert byte to H-floating
Convert byte to long
Convert byte to word
Convert D_floating to byte

76
32FD
6A
69
48
56
99FD
98FD
4A
49
48FD
33FD
56FD
4AFD
49FD

CVTDF
CVTDH
CVTDL
CVTDW
CVTFB
CVTFD
CVTFG
CVTFH
CVTFL
CVTFW
CVTGB
CVTGF
CVTGH
CVTGL
CVTGW

Convert D floating
Convert D-floating
Convert D-floating
Convert D-floating
Convert F-floating
Convert F-floating
Convert F-floating
Convert F-floating
Convert F-floating
Convert F-f loating
Convert G-floating
Convert G-f loating
Convert G-f loating
Convert G-floating
Convert G=f loating

68FD
F7FD
F6FD
76FD
6AFD
69FD
F6

CVTHB
CVTHD
CVTHF
CVTHG
CVTHL
CVTHW
CVTLB

Convert
Convert
Convert
Convert
Convert
Convert
Convert

51
51FD
71FD

Dl
35
37
EC
Bl
ED

to
to
to
to

executive
kernel
supervisor
user

to
to
to
to
to
to
to
to
to
to
to
to
to
to
to

F floating
H-floating
long
word
byte
D floating
G-f loating
H-floating
long
word
byte
F floating
H-f loating
long
word

H floating to
H-f loating to
H-floating to
H-floating to
H-floating to
H-floating to
long to byte

byte
D floating
F-floating
G-f loating
long
word

C-3

PERMANENT SYMBOL TABLE
Hexadecimal
Value

Mnemonic

Functional Name

6E
4E
4EFD
fiEFD
F9
F7
36
08
24
68

CVTLD
CVTLF
CVTLG
CVTLH
CVTLP
CVTLW
CVTPL
CVTPS
CVTPT
CVTRDL

Convert
Convert
Convert
Convert
Convert
Convert
Convert
Convert
Convert
Convert

CVTRFL
CVTRGL
CVTRHL
CVTSP
CVTTP
CVTWB
CVTWD
CVTWF
CVTWG
CVTWH
CVTWL
DECB

Convert rounded F floating to long
Convert rounded G-floating to long
Convert rounded H-floating to long
Convert leading separate to packed
Convert trailing to packed
Convert word to byte
Convert word to D floating
Convert word to F-floating
Convert word to G-f loating
Convert word to H-floating
Convert word to long
Decrement byte

DECL
DECW
DIVB2
DIVB3
DIVD2
DIVD3
DIVF2
DIVF3
DIVG2
DIVG3
DIVH2
DIVH3
DIVL2
DIVL3
DIVP
DIVW2
DIVW3
EDITPC
EDIV
EMO DD

Decrement long
Decrement word
Divide byte 2 operand
Divide byte 3 operand
Divide D floating 2 operand
Divide D-floating 3 operand
Divide F-floating 2 operand
Divide F-floating 3 operand
Divide G-floating 2 operand
Divide G-floating 3 operand
Divide H-floating 2 operand
Divide H-floating 3 operand
Divide long 2 operand
Divide long 3 operand
Divide packed
Divide word 2 operand
Divide word 3 operand
Edit packed to character
Extended divide
Extended modulus D_floating

EMODF
EMODG
EMO DH
EMUL
EXTV
EXTZV
FFC
FFS
HALT
INCB

Extended modulus F floating
Extended modulus G-f loating
Extended modulus H-floating
Extended multiply Extract field
Extract zero-extended field
Find first clear bit
Find first set bit
Halt
Increment byte

INCL
INCW
INDEX

Increment long
Increment word
Index calculation

4BFG
6BFD
09
26
33
60

40
4DFD
6DFD
32
97

87
86
87
66
67
46
47
46FD
47FD
66FD
67FD
C6
C7
27
A6

A7
38

78
74
54
54FD
74FD

7A
EE
EF
EB
EA
00
96

D6
86

long to D floating
long to F-f loating
long to G-f loating
long to H-f loating
long to packed
long to word
packed to long
packed to leading separate
packed to trailing
rounded D_floating to long

C-4

PERMANENT SYMBOL TABLE
Hexadecimal
Value

Mnemonic

Functional Name

SC
SD
OE
FO
17
16
06

INSQHI
INSQTI
INSQUE
INSV
JMP
JSB
LDPCTX

Insert into queue at head, interlocked
Insert into queue at tail, interlocked
Insert into queue
Insert field
Jump
Jump to subroutine
Load program context

3A
39
92
D2
B2
DB
8E
72

LOCC
MATCHC
MCOMB
MCOML
MCOMW
MFPR
MNEGB
MNEGD

Locate character
Match characters
Move complemented byte
Move complemented long
Move complemented word
Move from processor register
Move negated byte
Move negated D~floating

52
52FD
72FD
CE
AE
9E
7E
DE
7E
7EFD
DE
7EFD
7E

MNEGF
MNEGG
MNEGH
MNEGL
MNEGW
MOVAB
MOVAD
MOVAF
MOVAG
MOVAH
MOVAL
MOVAO
MOVAQ

Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move

negated F floating
negated G-floating
negated H-floating
negated long
negated word
address of byte
address of D floating
address of F-f loating
address of G-f loating
address of H-floating
address of long
address of octa
address of quad

3E
90
28
2C
70
50
50FD
70FD
DO
7DFD
34
DC
7D
2E
2F
BO
OA
9B
3C

MOVAW
MOVB
MOVC3
MOVC5
MOVD
MOVF
MOVG
MOVH
MOVL
MOVO
MOVP
MOVPSL
MOVQ
MOVTC
MOVTUC
MOVW
MOVZBL
MOVZBW
MOVZWL

Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move
Move

address of word
byte
character 3 operand
character 5 operand
D floating
F-floating
G-floating
H-floating
long
data
packed
program status longword
quad
translated characters
translated until character
word
zero-extended byte to long
zero-extended byte to word
zero-extended word to long

DA
84
85
64
65
44
45
44FD
45FD

MTPR
MULB2
MULB3
MULD2
MULD3
MULF2
MULF3
MULG2
MULG3

Move to processor register
Multiply byte 2 operand
Multiply byte 3 operand
Multiply D floating 2 operand
Multiply D-floating 3 operand
Multiply F-floating 2 operand
Multiply F-floating 3 operand
Multiply G-floating 2 operand
Multiply G=floating 3 operand

C-5

PERMANENT SYMBOL TABLE

Hexadecimal
Value

Mnemonic

Functional Name

64FD
6SFD
C4

MULH2
MULH3
MULL2

Multiply H floating 2 operand
Multiply H-floating 3 operand
Multiply long 2 operand

MULL3
MULP
MULW2
MULW3
NOP
POL YD
POLYF
POLYG
POLYH
POPR

Multiply long 3 operand
Multiply packed
Multiply word 2 operand
Multiply word 3 operand
No operation
Evaluate polynomial D floating
Evaluate polynomial F-floating
Evaluate polynomial G-floating
Evaluate polynomial H=floating
Pop registers

PROBER
PRO BEW
PUSHAB
PU SHAD
PUSHAF
PU SHAG
PU SHAH
PUS HAL
PU SHAO
PUS HAQ
PUSHAW

Probe read access
Probe write access
Push address of byte
Push address of D floating
Push address of F-floating
Push address of G-floating
Push address of H-floating
Push address of long
Push address of octa
Push address of quad
Push address of word

PUSHL
PUS HR
REI
REMQHI
REMQTI
REMQUE
RET
ROTL
RSB
SBWC

Push long
Push registers
Return from exception or interrupt
Remove from queue at head, interlocked
Remove from queue at tail, interlocked
Remove from queue
Return from called procedure
Rotate long
Return from subroutine
Subtract with carry

2A
3B
F4
FS
2B
82
83
62

SCANC
SKPC
SOBGEQ
SOBGTR
SPANC
SUBB2
SUBB3
SUBD2

Scan for character
Skip character
Subtract one and branch on greater or equal
Subtract one and branch on greater
Span characters
Subtract byte 2 operand
Subtract byte 3 operand
Subtract D_floating 2 operand

63
42
43
42FD
43FD
62FD
63FD
C2
C3
22
23
A2
A3

SUBD3
SUBF2
SUBF3
SUBG2
SUBG3
SUBH2
SUBH3
SUBL2
SUBL3
SUBP4
SUBP6
SUBW2
SUBW3

Subtract D floating 3 operand
Subtract F-floating 2 operand
Subtract F-floating 3 operand
Subtract G-f loating 2 operand
Subtract G-floating 3 operand
Subtract H-floating 2 operand
Subtract H-floating 3 operand
Subtract long 2 operand
Subtract long 3 operand
Subtract packed 4 operand
Subtract packed 6 operand
Subtract word 2 operand
Subtract word 3 operand

2S
A4
AS
01
7S
SS
SSFD
7SFD
BA

oc
OD
9F
7F
DF
7F
7FFD
DF
7FFD
7F
3F
DD
BB
02
SE
SF

OF
04

9C
OS

C-6

PERMANENT SYMBOL TABLE
Hexadecimal
Value
07
95
73
53
53FD
73FD
D5

BS
FC
8C
8D

CD
AC
AD

Mnemonic

Functional Name

SVPCTX
TSTB
TSTD
TSTF
TSTG
TSTH
TSTL
TSTW
XFC

Save process context
Test byte
Test D_floating
Test F floating
Test G- floating
Test I-I- floating
Test long
Test word
Extended function call

XORB2
XORB3
XORL2
XORL3
XORW2
XORW3

Exclusive-OR byte
Exclusive-OR byte
Exclusive-OR long
Exclusive-OR long
Exclusive-OR word
Exclusive-OR word

C-7

2 operand
3 operand
2 operand
3 operand
2 operand
3 operand

C.2

OPCODES (NUMERIC ORDER)

HEX

Value

Instruction

00
01
02
03
04
OS
06
07
OS
09
OA
OB

HALT
NOP
REI
BPT
RET
RSB
LDPCTX
SVPCTX
CVTPS
CVTSP
INDEX
CRC
PROBER
PROBEW
INSQUE
REMQUE
BSBB
BRB
BNEQ, BNEQU
BEQL, BEQLU
BGTR
B:r..EQ
JSB
JMP
BGEQ
BLSS
BGTRU
BLEQU
BVC
BVS
BCC, BGEQU
BCS, BLSSU
ADDP4
ADDP6
SUBP4
SUBP6
CVTPT

OD
OE
OF
10
11

CJ
I
(X)

12
13
14
lS
16
17
lS
19
lA

lB
lC
10
lE
lF
20
21
22
23
24
2S
26
27
2S
29
2A
2B
2C
2D
2E
2F

MULP

CVTTP
DIVP
MOVC3
CMPC3
SCANC
SPANC
MOVCS
CMPCS
MOVTC
MOVTUC

HEX
Value
30
31
32
33
34
3S
36
37
3S
39
3A
3B
3C
3D
3E
3F
40
41
42
43
44
4S
46
47
4S
49
4A
4B
4C
40
4E
4F

Sl
S2
S3
S4
SS
S6
S7
SS
S9
SA
SB
SC
SD
SE
SF

Instruction

HEX
Value

BSBW
BRW
CVTWL
CVTWB
MOVP
CMPP3
CVTPL
CMPP4
EDITPC
MATCHC
LOCC
SKPC
MOVZWL
ACBW
MOVAW
PUSHAW
ADDF2
ADDF3
SUBF2
SUBF3
MULF2
MULF3
DIVF2
DIVF3
CVTFB
CVTFW
CVTFL
CVTRFL
CVTBF
CVTWF
CVTLF
ACBF
MOVF
CMPF
MNEGF
TSTF
EMODF
POLYP
CVTFD
reserved
ADAWI
reserved
reserved
reserved
INSQHI
INSQTI
REMQHI
REMQTI

60
61
62
63
64
6S
66
67
6B
69
6A
6B
6C
6D
6E
6F
70
71
72
73
74
7S
76
77
7S
79
7A
7B
7C
70
7E
7F
80
Sl
S2
S3
B4
SS
B6
87
BS
S9
SA
BB
SC
SD
BE
SF

Instruction
ADDD2
ADDD3
SUBD2
SUBD3
MULD2
MULD3
DIVD2
DIVD3
CVTDB
CVTDW
CVTDL
CVTRDL
CVTBD
CVTWD

HEX
Value
90
91
92
93
94
9S
96
97
9B
99
9A
9B
9C
9D
9E
9F
AO
Al
A2
A3
A4
AS
A6
A7
AS
A9

CVTLD
ACBD
MOVD
CMPD
MNEGD
TSTD
EMODD
POL YD
CVTDF
reserved
ASHL
ASHQ
EMUL
AA
EDIV
AB
CLRD, CLRQ, CLRG
AC
MOVQ
AD
MOVAD, MOVAQ, MOVAG
AE
PUSHAD, PUSHAQ, PU SHAG AF
ADDB2
BO
ADDB3
Bl
SUBB2
B2
SUBB3
B3
MULB2
B4
MULB3
BS
DIVB2
B6
DIVB3
B7
BISB2
BS
BISB3
B9
BICB2
BA
BICB3
BB
XORB2
BC
XORB3
BD
MNEGB
BE
CASEB
BF

Instruction
MOVB
CMPB
MCOMB
BITB
CLRB
TSTB
INCB
DECB
CVTBL
CVTBW
MOVZBL
!oiOVZBW
ROTL
ACBB
MOVAB
PUSHAB
ADDW2
ADDW3
SUBW2
SUBW3
MULW2
MULW3
DIVW2
DIVW3
BISW2
BISW3
BICW2
BICW3
XORW2
XORW3
MNEGW
CASEW
MOVW
CMPW
MCOMW
BITW
CLRW
TSTW
INCW
DECW
BISPSW
BICPSW
POPR
PUS HR
CHMK
CHME
CHMS
CHMU

HEX
Value

co
Cl
C2
C3
C4

cs
C6
C7
CB
C9
CA

CD
CE

DO
Dl
D2
D3
D4
DS
D6
D7
DS
D9
DA
DB
DC

DD
DE
DF
EO
El
E2
E3
E4
ES
E6
E7
EB
E9
EA

EB
EC
ED
EE
EF

Instruction

HEX
Value

FO
ADDL2
Fl
ADDL3
F2
SUBL2
F3
SUBL3
F4
MULL2
FS
MULL3
DIVL2
F6
F7
DIVL3
FS
BISL2
F9
BISL3
FA
BICL2
FB
BICL3
FC
XORL2
XORL3
FD
MNEGL
FE
CASEL
FF
32FD
MOVL
CMPL
33FD
MCOML
40FD
BITL
41FD
CLRF, CLRL
42FD
TSTL
43FD
INCL
44FD
DECL
4SFD
46FD
ADWC
SBWC
47FD
MTPR
4SFD
MFPR
49FD
MOVPSL
4AFD
PUSHL
4BFD
MOVAF, MOVAL
4CFD
PUSHAF, PUSHAL 4DFD
BBS
4EFD
BBC
4FFD
BBSS
SOFD
BBCS
SlFD
S2FD
BBSC
S3FD
BBCC
BBSSI
S4FD
SSFD
BBCCI
S6FD
BLBS
60FD
BLBG
FFS
61FD
FFC
62FD
CMPV
63FD
CMPZV
64FD
EXTV
6SHD
EXTZV
66FD

Instruction
INSV
ACBL
AO BL SS
AOBLEQ
SOBGEQ
SOBGTR
CVTLB
CVTLW
ASHP
CVTLP
CALLG
CALLS
XFC
reserved
reserved
reserved
CVTDH
CVTGF
ADDG2
ADDG3
SUBG2
SUBG3
MULG2
MULG3
DIVG2
DIVG3
CVTGB
CVTGW
CVTGL
CVTRGL
CVTBG
CVTWG
CVTLG
ACBG
MOVG
CMPG
MNEGG
TSTG
EMODG
POLYG
CVTGH
ADDH2
ADDH3
SUBH2
SUBH3
MULH2
MULH3
DIVH2

HEX
Value
67FD
6SFD
69FD
6AFD
6BFD
6CFD
6DFD
6EFD
6FFD
70FD
71FD
72FD
73FD
74FD
7SFD
76FD
7CFD
7DFD
7EFD
7FFD
9SFD
99FD
F6FD
F7FD

Instruction
DIVH3
CVTHB
CVTHW
CVTHL
CVTRHL
CVTBH
CVTWH

CVTLH
ACBH
MOVH
CMPH
MNEGH
TSTH
EMODH
POLYH
CVTHG
CLRH, CLRO
MOVO
MOVAH, MOVAO
PUSHAB, PUSHAO
CVTFH
CVTFG
CVTHF
CVTHD

.,,
,,
t:rJ

z~
t:rJ
z
toi

°'

t""

toi

°'

t""
t:rJ

APPENDIX D

HEXADECIMAL/DECIMAL CONVERSION

Table D-1 lists the decimal value for each possible hexadecimal value
in
each
byte of a longword.
The following sections contain
instructions to use the table to convert hexadecimal numbers to
decimal and vice versa.

D.l

HEXADECIMAL TO DECIMAL

For each integer position of the hexadecimal value, locate the
corresponding column integer and record its decimal equivalent in the
conversion table. Add the decimal equivalent to obtain the decimal
value.
For example:
D0500ADO {16)

D.2

?{10)

DOOOOOOO
500000
AOO
DO

3,489,660,928
5,242,880
2,560
208

D0500ADO

3,494,904,576

DECIMAL TO HEXADECIMAL

Step 1: locate in the conversion table the largest decimal value that
does not exceed the decimal number to be converted. Step 2: record
the hexadecimal equivalent followed by the number of Os
that
corresponds to the integer column minus 1. Step 3: subtract the
table decimal value from the decimal number to be converted. Step 4:
repeat steps 1 through 3 until the subtraction balance equals o. Add
the hexadecimal equivalents to obtain the hexadecimal value.

D-1

HEXADECIMAL/DECIMAL CONVERSION
Example:
22,466 (10)

= ?(16)

20,480
1,792
192

5000
700

22,4nn
-20,480

l,98n
- 1,792

22,466

57C2

194
192
2
2

D.3

POWERS OF 2 AND 16

This section lists the decimal values of powers of 2 and 16.
These
values are often useful in converting decimal numbers to hexadecimal.
Powers of 2

Powers of Hi

2**n

Hi**n

256
512
1024
2048
4096
8192
16384
32768
65536
131072
262144
524288
1048576
2097152
4194304
8388608
16 777 216

8
9
10
11
12
13
14
15

1
16
256
4096
65536
1048576
111777216
2'18435456
4294%7296
n8719476736
1099511627776
175921860444ln
28147497671065()
450359962737049fi
72057594037927936
115292150460l184n976

0
l

17
18
19
20
21
22
23
24

D-2

2
3
4
5
fi
7
8
9
10
11
12
13
14
15

Table D-1
Hexadecimal/Decimal Conversion

HEX

DEC

HEX

0
1
2
3
4
5
6
7
8
9

0
268,435,456
536,870,912
805,306,368
1,073,741,824
1,342,177,280
1,610,612,736
1,879,048,192
2,147,483,643
2,415,919,104
2,684,354,560
2,952,790,016
3,221,225,472
3,489,660,928
3,758,096,384
4,026,531,840

D
E
F

DEC
0

16,777,216
33,554,432
50,331,648
67,108,864
83,886,080
100,663,296
117,440,512
134,217,728
150,994,944
167, 772 ,160
184,549,376
201,326,592
218,103,808
234,881,024
251,658,240

HEX

DEC

HEX

DEC

HEX

DEC

HEX

DEC

HEX

DEC

HEX

DEC

0
1
2
3
4
5
6
7
8
9

0
1,048,576
2,097,152
3,145,728
4,194,304
5,242,880
6,291,456
7,340,032
8,388,608
9,437,184
10,485,760
11,534,336
12,582,912
13,631,488
14,680,064
15,728,640

0
1
2
3
4
5
6
7
8
9

0
65,536
131,072
196,608
262,144
327,680
393,216
458,752
524,288
589,824
655,360
720, 896
786,432
851,968
917,504
983,040

0
1
2
3
4
5
6
7

0
4,096
8,192
12,288
16,384
20,480
.24,576
28,672
32,768
36,864
40,960
45,056
49,152
53,248
57,344
61,440

0
1
2
3
4
5
6
7
8
9

0
256
512
768
1,024
1,280
1,536
1,792
2,048
2,304
2,560
2,816
3,072
3,328
3,584
3,840

0
1
2
3
4
5
6
7
8
9

0
16
32
48
64
80
96
112
128
144
160
176
192
208
224
240

0
1
2
3
4
5
6
7
8
9

0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

c
D
E
F

D
E
F

9
A

c
D
E
F

D
E
F

::c

tSJ

>
0

tSJ

t-1

'n
0

tSJ

t-1

0
z
<
tSJ

,,
Cll

BYTE

BYTE
WORD

BYTE

BYTE
WORD

LONGWORD

t-1

INDEX

A
AA operator, 3-11, 3-13
Absolute,
index mode, 4-15, 4-17
mode, 4-3, 4-13, 4-14
program sections, 5-46, 5-48
ABS program section attribute,
5-48
Accuracy of floating-point
numbers, 3-4
Addition, 3-15
Address data,
initializing memory with, 5-3
reserving memory for, 5-9
.ADDRESS directive, 5-3
Address, starting, 5-21, 5-22
Address, transfer, 5-20, 5-21
Addressing modes, 2-3, 4-1
through 4-18
summary of, 4-2 through 4-4,
B-11 through B-13
.ALIGN directive, 5-4, 5-5
Alignment,
data, 5-4, 5-5
location counter, 5-4, 5-5,
5-24' 5-41
program section, 5-47, 5-50
AMA argument, 5-18
AND operator, 3-16
AP register, 3-5
Argument,
concatenation in macros, 6-6
macro, 6-1 through 6-8
pointer, 3-5
Arithmetic shift,
operator, 3-16
Arithmetic trap enable, 3-13, 3-14
.ASCIC directive, 5-7
.ASCID directive, 5-8
ASCII character set, A-1
.ASCII directive, 5-7
ASCII,
hexadecimal conversion, A-1
operator, 3-11, 3-13
strings, 3-11, 3-13, 5-6
through 5-9
string storage, 5-6 through 5-9
.ASCix storage directives, 5-6
through 5-9
.ASCIZ directive, 5-8
Assembler directives, 2-3, 5-1
through 5-67, 6-1 through 6-29
summary of, 5-1, 5-2, 6-2, B-1
through B-7
Assembler functions, 5-17 through
5-19

Assigning a value, 3-17
Assignment statements, 3-17, 3-18
Attributes, program section, 5-46
through 5-50
Autodecrement index mode, 4-15,
4-17
Autodecrement mode, 4-7
Autoincrement deferred index mode,
4-15, 4-16, 4-17
Autoincrement deferred mode, 4-6,
4-7
Autoincrement index mode, 4-15,
4-16, 4-17
Autoincrement mode, 4-6

B
BA displacement specifier, 4-8,
4-9' 4-12
AB unary operator, 3-11, 3-12
Base mode, 4-15, 4-17
Binary operators, 3-15 through
3-17, B-10
Binary radix, 3-11, 3-12
Blank lines, 2-2
.BLKA directive, 5-9, 5-10
.BLKB directive, 5-9, 5-10
.BLKD directive, 5-9, 5-10
.BLKF directive, 5-9, 5-10
~BLKG directive, 5-9, 5-10
.BLKH directive, 5-9, 5-10
.BLKL directive, 5-9, 5-10
.BLKO directive, 5-9, 5-10
.BLKQ directive, 5-9, 5-10
.BLKW directive, 5-9, 5-10
.BLKx directives, 5-9, 5-10
Block labels, 3-7, 3-8
Block storage directives, 5-9,
5-10
Branch addresses, 3-8
Branch instructions, 4-18
Branch mode, 4-18
Byte data,
initializing memory with, 5-11,
5-57
reserving memory for, 5-9, 5-10,
.BYTE directive, 5-11

c
Ac operator, 3-15
Call instruction, 5-21, 5-22
Character,
indefinite repeat block, 6-16,
6-17

Index-1

INDEX

Character, {Cont.)
separating, 3-3
set, 3-1, 3-2
set, ASCII, A-1
special, 3-1, 3-2, B-7, B-8
strings, 3-12, 3-13, 5-6
through 5-8
Characters, counting, 6-9, 6-25
Combining arguments in macros,
6-6
Comment field, 2-1, 2-4
Complement operator, 3-15
Concatenated program sections,
5-48
Concatenating arguments in
macros, 6-6
Conditional assembly blocks,
5-30 through 5-36
controlling listing of, 5-55,
5-56
one line block, 5-36
subconditionals, 5-33 through
5-35
Condition tests, 5-30, 5-31
CON program section attribute,
5-48
Continuation lines, 2-2
Continuing program sections, 5-46
Controlling listings, 5-55, 5-56
Counted ASCII string storage, 5-7
Counter, current location, 3-18
Counting characters, 6-9, 6-25
Counting macro arguments, 6-24
Counts, repeat, 3-10, 5-11, 5-38,
5-57, 5-S8, 5-67
Created local labels, 6-7, 6-8
.CROSS directive, 5-12, 5-13
Cross reference listing, 5-12,
5-13
Current location counter, 3-18

D
AD unary operator, 3-11, 3-12
Data alignment, 5-4, 5-5
Data, reserving memory for, 5-9
Data, initializing memory with,
address, 5-3
ASCII, 5-6 through 5-8
byte, 5-11, 5-57
D floating, 5-16
Double precision, 5-16
F floating, 5-25
floating-point, 5-16, 5-25,
5-26, 5-28
G floating, 5-26
H-floating, 5-28
longword, 5-38
octaword, 5-41

Data, initializing memory
with, {Cont.)
packed decimal, 5-44
quadword, 5-51
signed, 5-57, 5-58, 5-59
word, 5-58, 5-67
DBG argument, 5-18
.DEBUG directive, 5-14
Debugging information, 5-14, 5-18
Decimal/hexadecimal conversion,
D-1 through D-4
Decimal radix, 3-11, 3-12
Decimal strings, 3-4, 3-5, 5-44
.DEFAULT directive, 5-15
Default program sections, 5-46,
5-50
Default radix, 3-12
Default values of macro
arguments, 6-3
Deferred mode,
autoincrement, 4-6, 4-7
displacement, 4-9
register, 4-5
relative, 4-12
Defining,
labels, 2-2
macros, 6-19, 6-20
opcodes, 5-42, 5-43
Degree of precision, 3-4
Deleting a macro, 6-22
Delimited ASCII strings, 5-6
Delimiters in macro arguments,
6-4 through 6-6
Descriptors, string, 5-8
D_floating data,
initializing memory with, 5-16
reserving memory for, 5-9, 5-10
.D_FLOATING directive, 5-16
Direct assignment statements,
3-17, 3-18
Directives, 2-3, 3-5, 5-1 through
5-67, 6-1 through 6-29
summary of, 5-1, 5-2, 6-2, B-1
through B-7
.DISABLE directive, 5-17 through
5-19
LOCAL BLOCK attribute, 3-8
Disabli~g assembler functions,
5-17 through 5-19
Displacement,
controlling default, 5-15
deferred index mode, 4-15
through 4-17
deferred mode, 4-9
index mode, 4-15 through 4-17
mode, 4-7, 4-8
specifier, 4-8, 4-9, 4-12
Division, 3-15
Documenting a program, 2-4

Index-2

INDEX
.DOUBLE directive, 5-16
Double precision, 3-4, 5-16
Double-precision data,
initializing memory with, 5-16
reserving memory for, 5-9, 5-10
.DSABL directive, 5-17 through
5-19

DV arithmetic trap enable, 3-13,
3-14

E
.ENABL directive, 5-17 through
5-19

.ENABLE directive, 5-17 through
5-19

LOCAL_BLOCK attribute, 3-8
Enabling assembler functions, 5-17
through 5-19
.END directive, 5-20
.ENDC directive, 5-20, 5-30
through 5-35
Ending,
conditional assembly blocks,
5-20, 5-30 through 5-35
macro definitions, 6-13, 6-19,
6-20

modules, 5-20
repeat range definitions, 6-13,
6-14 through 6-17
.ENDM directive, 6-13, 6-19, 6-20
.ENDR directive, 6-13 through

F
AF operator, 3-14, 3-15
Factors, repetition, 3-10, 5-11,
5-38, 5-57, 5-58, 5-67

Field,
comment, 2-1, 2-4
label, 2-1 through 2-3
operand, 2-1, 2-3, 2-4
operator, 2-1, 2-3
F floating data,
initializing memory with, 5-25
reserving memory for, 5-9, 5-10
.F FLOATING directive, 5-25
.FLOAT directive, 5-25
Floating-point data,
initializing memory with, 5-16,
5-25, 5-26, 5-28

reserving memory for, 5-9, 5-10
Floating-point expressio~s, 3-14
Floating-point numbers, 3-3, 3-4,
3-14, 3-15

format of, 3-4
rounding of, 5-17, 5-19
truncation of, 5-17, 5-19
Floating-point operator, 3-14
Floating-point short literals,
4-10

Format, statement, 2-1 through 2-4
Formatting with tabs, 2-1, 2-2
FP register, 3-6, 3-14
FPT attribute, 5-19
Frame pointer, 3-6
Functions, assembler, 5-17 through

6-17

5-19

.ENTRY directive, 5-21
Entry mask, 3-13, 3-14, 5-20, 5-21,
5-39

.ERROR directive, 5-23
Exclusive OR operator, 3-17
Executable program sections, 5-46
through 5-50
EXE program section attribute,
5-48

Expanding a macro, 6-1, 6-2
Exponent, 3-4
Expressions, 3-9, 3-10
evaluation of, 3-9
floating point, 3-14
restrictions on, 3-10
Extended precision, 3-4, 5-28
.EXTERNAL directive, 5-24
External symbols, 3-7, 5-24, 5-27,
5-66

%EXTRACT macro string operator,
6-11, 6-12

.EXTRN directive, 5-24
.EVEN directive, 5-24
Exiting a macro, 6-13, 6-19, 6-20

G
GBL argument, 5-18, 5-19
GBL program section attribute,
5-48

General mode, 4-14
General registers, 3-5
General register modes, 4-1
through 4-11
G floating data,
-initializing memory with, 5-26
reserving memory for, 5-9, 5-10
.G_FLOATING directive, 5-26
GLOBAL argument, 5-18, 5-19
Global attribute, 5-48, 5-49
.GLOBAL directive, 5-27
Global program sections, 5-48
Global symbols, 2-2, 3-7, 3-17,
5-18, 5-19, 5-24, 5-27, 5-66

defining, 2-2
weak, 5-66
.GLOBL directive, 5-27

Index-3

INDEX

.IRPC directive, 6-16, 6-17
IV arithmetic trap enable, 3-14

Hexadecimal/ASCII conversion, A-1
Hexadecimal/decimal conversion,
D-1 through D-4
Hexadecimal radix, 3-11, 3-12
H floating data,
-initializing memory with, 5-28
reserving memory for, 5-9, 5-10
.H FLOATING directive, 5-28

K
Keyword arguments in macros, 6-3,
6-4

L
L~

addressing mode, 4-14, 4-15
.IDENT directive, 5-29
Identifying a module, 5-29, 5-61
.IF directive, 5-30 through 5-32
.IF_FALSE directive, S-33 through
5-35
.IF_TRUE directive, 5-33 through
5-35
.IF TRUE FALSE directive, 5-33
-through 5-35
.IFF directive, 5-33 through 5-35
.IFT directive, 5-33 through 5-35
.IFTF directive, 5-33 through
5-35
.IFx directives, 5-33 through
5-35
.IIF directive, 5-36
Immediate conditional block, 5-36
Immediate mode, 4-13, 4-14
Inclusive OR operator, 3-15, 3-17
Indefinite repeat blocks, 6-14,
6-15
Indefinite repeat character blocks,
6-16, 6-17
Index mode, 4-15 through 4-17
Initializing memory with
address data, 5-3
ASCII data, 5-6 through 5-8
byte data, 5-11, 5-57
D floating data, 5-16
fToating-point data, 5-16, 5-25,
5-26, 5-28
G floating data, 5-26
H-floating data, 5-28
longword data, 5-38
octaword data, 5-41
packed data, 5-44
quadword data, 5-51
word data, 5-58, 5-67
Instructions, 1-1, 2-3, 3-5, C-1
through C-8
redefining, 5-42, 5-43, 6-20
Integer expressions, 3-9, 3-10
Integers, 3-3
Internal symbols, 2-2, 3-7, 3-17
.IRP directive, 6-14, 6-15

displacement specifier, 4-8,
4-9, 4-12, 4-13
Label,
defining a, 2-2
field, 2-1, 2-2
local, 3-7, 3-8
names, 2-2
terminator, 2-2
LCL program section attribute,
5-48
%LENGTH macro string operator,
6-9
Length of source line, 2-1
Lexical operators, 6-8 through
6-12
.LIBRARY directive, 6-18
Lines, continuation, 2-2
.LIST directive, 5-37, 5-55, 5-56
Listing,
control of, 5-44, 5-55, 5-56
cross reference, 5-13, 5-14
table of contents, 5-59
Literal mode, 4-10 through 4-12
Literals, short, 4-10 through
4-12
Local label block,
delimiters, 3-8
disabling, 3-8, 5-17, 5-18
enabling, 3-8, 5-17, 5-18
restoring, 5-53
saving, 5-54
Local labels, 3-7, 3-8, 5-17, 5-18
created, 6-7, 6-8
Local program sections, 5-48, 5-49
%LOCATE macro string operator,
6-10, 6-11
Location counter, 3-18
alignment, 5-4, 5-5, 5-24, 5-41
Logical AND operator, 3-16
Logical exclusive OR operator,
3-17
Logical inclusive OR operator,
3-17
.LONG directive, 5-38
Longword data,
initializing memory with, 5-38
reserving memory for, 5-9, 5-10
LSB argument, 3-8, 5-18

Index-4

INDEX

M
AM operator, 3-13, 3-14
Machine instructions, 1-1
.MACRO directive, 6-19, 6-20
Macros, 6-1 through 6-29
arguments in, 6-1 through 6-8
calls to, 2-3
controlling listing of, 5-55, 5-56
definitions of, 6-19, 6-20
deletion of, 6-22
exiting from, 6-23
expanding, 6-1, 6-2
libraries containing, 6-18
maximum line size, 2-2
names of, 3-6, 6-13, 6-19, 6-20
redefining, 6-19, 6-20
string operators in, 6-8 through
6-12
.MASK directive, 5-21, 5-39
Mask operator, 3-13, 3-14
Mask, register save, 3-13, 3-14,
5-21, 5-39
.MCALL directive, 6-21
.MDELETE directive, 6-22
Messages, printing assembly, 5-23,
5-45, 5-65
.MEXIT directive, 6-23
Mnemonic instructions, 3-5, C-1
through C-8
Modes, addressing, 2-3, 4-1
through 4-18
summary of, 4-2 through 4-4,
B-11 through B-13
Module, identifying, 5-29, 5-61
Multiplication, 3-15

N
Names,
macro, 3-6, 6-13, 6-19, 6-20
module, 5-61
register, 3-5
symbol, 3-6
.NARG directive, 6-24
.NCHR directive, 6-25
Negative numbers, 3-3
.NLIST directive, 5-39, 5-55,
5-56
.NOCROSS directive, 5-12, 5-13,
5-40
NOEXE program section attribute,
5-48
NOPIC program section attribute,
5-48
.NOSHOW directive, 5-39, 5-55,
5-56
NOSHR program section attributes,
5-48

NOWRT program section attribute,
5-49
.NTYPE directive, 6-26
Number of macro arguments, 6-1,
6-24
Numbers, 3-3
floating point, 3-3, 3-4, 3-14,
3-15, 5-16, 5-25, 5-26, 5-28
integer, 3-3
packed decimal, 3-4, 3-5, 5-44
Numeric control operators, 3-14,
3-15

0
Ao unary operator, 3-11, 3-12
.OCTA directive, 5-41
Octal radix, 3-11, 3-12
Octaword data,
initializing memory with, 5-28
reserving memory for, 5-9, 5-10
.ODD directive, 5-41
Opcodes, C-1 through C-8
defining, 5-42, 5-43
redefining, 5-42, 6-20
.OPDEF directive, 5-42, 5-43
Operand,
descriptors, 5-43
field, 2-1, 2-3
generation directives, 5-52
types, 6-26
Operator,
binary, 3-15 through 3-17, B-9
field, 2-1, 2-3
macro string, 6-8 through 6-12,
B-10
unary, 3-10 through 3-15, B-8,
B-10
OR operators, 3-17
Overlaid program sections, 5-49
OVR program section attribute, 5-49

p
Packed decimal strings, 3-4, 3-5,
5-44
.PACKED directive, 5-44
.PAGE directive, 5-44
Page ejection, 5-44
Passing numeric values in macros,
6-7
PC register, 3-6
Permanent symbols, 3-5, C-1
PIC program section attribute,
5-49
Position-independent code, 5-49
Precision of floating-point
numbers, 3-4

Index-5

INDEX

.PRINT directive, 5-45
Printing assembly messages, 5-23,
5-45' 5-65
Privileged shareable image attribute, 5-49
Program counter, 3-6
Program counter modes, 4-11
through 4-14
Program section attributes, 5-48,
5-49
def a ult, 5-49
Program sections, 5-46 through
5-50, 5-53, 5-54

Q
.QUAD directive, 5-51
Quadword data,
initializing memory with, 5-51
reserving memory for, 5-9, 5-10

R
Radix control, 3-11, 3-12
Radix default, 3-11
Radix operators, 3-11, 3-12
in macro arguments, 6-5
Rea~ numbers, 3-3, 3-4
Redefining
instructions, 5-42, 6-20
macros, 6-19, 6-20
opcodes, 5-42, 6-20
.REFn directive, 5-52
Register,
deferred index mode, 4-15
through 4-17
deferred mode, 4-5
mask operator, 3-13, 3-14
mode, 4-5
names, 3-5, 3-6
save mask, 3-13, 3-14, 5-21,
5-39
Relative,
default displacement, 5-15
deferred index mode, 4-15, 4-17
deferred mode, 4-12
index mode, 4-15, 4-17
mode, 4-11, 4-12
Relocatable program sections,
5-49' 5-50
REL program section attribute,
5-49
Repeat blocks, 6-28, 6-29
character, indefinite repeat,
6-16, 6-17
controlling listing of, 5-55,
5-56
indefinite, 6-14, 6-15

Repeat counts, 3-10, 5-11, 5-38,
5-57, 5-58, 5-67
.REPEAT directive, 6-28, 6-29
Repeating a block of code, 6-28,
6-29
Repetition factors, 3-10, 5-11,
5-38, 5-57, 5-58, 5-67
.REPT directive, 6-28, 6-29
.RESTORE directive, 5-53
.RESTORE PSECT directive, 5-53
Restoring a program section, 5-53
Reserved bits in entry mask, 3-14,
5-21
Reserving storage, 5-9
Rounding floating-point numbers,
5-19

s
SA addressing mode, 4-10 through
4-12
.SAVE directive, 5-54
.SAVE PSECT directive, 5-54
Saving a program section, 5-54
Saving local label block, 5-54
.SBTTL directive, 5-60
Sections, program, 5-46 through
5-50, 5-53, 5-54
Separating charactars, 3-3
Shareable images, 5-62 through
5-64
Shareable program sections, 5-49
Shift operator, arithmetic, 3-16
Short literals, 4-10, 4-11
.SHOW directive, 5~55, 5-56
SHR program section attribute, 5-49
.SIGNED BYTE directive, 5-57
Signed data storage, 5-57 through
5-59
.SIGNED WORD directive, 5-58,
5-59
Single precision, 3-4, 5-25
Single-precision data,
initializing memory with, 5-25
reserving memory for, 5-9, 5-10
Source lines,
blank, 2-2
continuing, 2-2
format of, 2-1
length of, 2-1
SP register, 3-6
Special characters, 3-1, 3-2,
B-7, B-8
Stack pointer, 3-6
Starting address, 5-21, 5-22
Statement format, 2-1 through 2-4
Storage, reserving, 5-9
ASCII, 5-6 through 5-8
block, 5-9

Index-6

INDEX

Storing,
address, 5-3
ASCII, 5-6 through 5-8
byte, 5-11, 5-57
D floating, 5-16
double-precision, 5-16
F floating, 5-25
floating-point, 5-25
G floating, 5-26
H-floating, 5-28
longword, 5-37
octaword, 5-28
packed decimal, 5-42
signed, 5-57, 5-58
quadword, 5-51
word, 5-58, 5-67
String,
arguments in macros, 6-4 through
6-6
ASCII, 3-12, 3-13, 5-6
descriptors, 5-8
operators, 6-8 through 6-12
packed decimal, 3-4, 3-5, 5-44
Subconditional assembly blocks,
5-33 through 5-35
.SUBTITLE directive, 5-60
Subtraction, 3-15
Suppressing symbol table listing,
5-17, 5-18
Symbols, 3-5, 3-17
external, 3-7, 5-24, 5-27, 5-66
global, 2-2, 3-7, 3-17, 5-18,
5-19, 5-24, 5-27, 5-66
internal, 3-7
names of, 3-6
permanent, 3-5, C-1
undefined, 5-17 through 5-19
user-defined, 2-2, 3-6

T
Tab formatting, 2-1, 2-2
Table of contents, listing, 5-60
TBK argument, 5-18
Temporary labels, 3-7, 3-8
Terms, 3-9
Testing conditions, 5-30 through
5-32
Textual operators, 3-12 through
3-14
.TITLE directive, 5-61
Traceback information, 5-18
.TRANSFER directive, 5-62 through
5-64
Trap enable, arithmetic, 3-13,
3-14
Truncating floating-point number,
5-19

Type of operand in macros, 6-24

u
Unary operators, 3-11 through
3-15, B-9
in macro arguments, 6-5
summary of, 3-11, B-9
Undefined symbols, 5-17 through
5-19
User-defined program sections,
5-46 through 5-50
User-defined symbol, 2-2
User-generated
errors, 5-23
messages, 5-45
opcodes, 5-42, 5-43
operands, 5-52
warnings, 5-65

v
Value, passing arguments by, 6-7
VEC program section attribute,
5-49
Vector, transfer, 5-62 through
5-64
Version number, 5-29

w
WA displacement specifier, 4-8,
4-9, 4-12, 4-13
.WARN directive, 5-65
Warning directive, 5-65
.WEAK directive, 5-66
Weak symbols, 5-66
Word data,
initializing memory with, 5-58,
5-67
reserving memory for, 5-9, 5-10
.WORD directive, 5-67
Write protecting program sections,
5-46, 5-49, 5-50
WRT program section attribute,
5-49

x
AX unary operator, 3-12

z
Zero terminated ASCII stririg, 5-8

Index-7

VAX-11 MACRO

Language Reference Manual
AA-D032C-TE
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