Appendix D. Machine Instruction Mnemonic Operation Code.

173 Pages·2009·10.64 MB·English

File No. 8360-21
Order No. GC28-6514-9
Systems Reference Library
OS Assembler Language
OS Release 21
This publication contains specifications
for the ~BM System/360 Operating System
Assembler Language (Leyels E and F) .
The assembler language is a symbolic
programming language used to write programs
for the IBM System/360. The language pro
vides a convenient means for representing
the machine instructions and related data
necessary to program the IBM System/360.
The IBM Systelt1/360 Operating System Assem
bler Program processes the language and
provides auxiliary functions useful in the
preparation and documentation of a program,
and includes facilities for processing the
assembler macro language.
Part I of this publication describes the
assembler language.
Part II of this publication describes an
extension of the assembler language -- the
macro language used to define macro
instructions.
PREFACE
This publication is a reference manual operations are discussed in the publication
for the programmer using the assembler IBM System/360 Principles of Operation,
language and its features. Order No. GA22-682l. The IBM System/370
machine operations are discussed in the
Part I of this publication presents publication IBM System/370 Principles of
information common to all parts of the Operation, Order No. GA22-7000. Information
language followed by specific information on program assembling, linkage editing,
concerning the symbolic machine instruction executing, interpreting listings, and
codes and the assembler program functions assembler programming considerations is
provided for t:he programmer I s use. Part II provided in OS Assembler (F} Programmer's
contains a description of the macro lan Guide, Order No. GC26-3756.
guage and procedures for its use.
Appendixes A through J follow Part II.
Appendixes A through F are associated with
The following publications are referred to
Parts I and II and present such items as a
in this publication:
summary chart for constants, instruction
listings, character set representations,
OS Introduction, Order No. GC28-6534
and other aids to programming. Appendix G
contains macro language summary charts, and
OS Utilities, Order No. GC28-6586
Appendix H is a sample program. Appendix I
is a features comparison chart of
System/360 assemblers. Appendix J includes OS Loader and Linkage Edito~,
Order No. GC28-6538
samples of macro definitions.
Knowledge of IBH System/360 machine OS Supervisor Services and Macro
operations, particularly storage address Instructions, Order No. GC28-6646
ing, data formats, and machine instruction
formats and functions, is prerequisite to OS Data Management Macro Instructions,
using this publication, as is experience Order No. GC26-3794
with programming concepts and techniques or
completion of basic courses of instruction OS Data Management Services Guide,
in these areas. IBM System/360 machine Order No. GC26-3746
lenth Edition (January, 1974)
This is a reprint of GC28-6514-8 incorporating changes released in the following Technical
Newsletter:
GN33-8154 (dated April 30, 1973)
This Technical Newsletter is a part of release 21.7 of OS/MPT and OS/MVT.
This edition applies to release 21 of IBM System/360 Operating System and to all subsequent
releases until otherwise indicated in new editions or Technical Newsletters. Changes are continually
made to specifications herein; before using this publication in connection with the operation of
IBM systems, consult tJile IBM System/360 and System/370 Bibliography, Order No. GA22-6822,
for the editions that are applicable and current.
Requests for copies of IBM publications should be made to your IBM representative or to the IBM
branch office serving your locality.
A form is provided at the back of this publication for readers' comments. If the form has been
removed, comments may be addressed to IBM Nordic Laboratory, Product Communications,
Box 962, S-181 09 Lidingo 9, Sweden. Comments become the property of IBM.
©Copyright International Business Machines Corporation 1966, 1968, 1969, 1970, 1972, 1974
CONTENTS
PART 1 -- THE ASSEMBLER LANGUAGE CSECT -- Identify Control
SECTION 1: INTRODUCTION. 3 Section • • • • • • • • • • 23
Compatibility •• 3 Unnamed Control Section. • • 24
DSECT -- Identify Dummy Section. • 24
The Assembler Language • • 3 External Dummy Sections(Assemb1er F}. 25
Machine Operation Codes. 3 DXD -- Define External Dummy
Assembler Operation Codes •• 3 Section. • • • • • • • • • • • • • • 25
Macro Instructions • 3 CXD - Cumulative Length External
Dummy Section. • • • • • • •• • • • 25
The Assembler Program. 4 COM -- Define Blank Common Control
Basic Functions. 4 Section. • • • • • • • • • • • 26
Symbolic Linkages • • •• • • • 26
Programmer Aids. 4 ENTRY -- Identify Entry-Point
Symbol • • • •• • • • • • • • • 27
Operating System Relationships • 5 EXTRN -- Identify External Symbol • • 27
Addressing External Control
SECTION 2: GENERAL INFORMATION •• 7 sections. • • • • • • • • 28
AsseJ';:.)ler Language Coding Conventions. • 7 SECTION 4: MACHINE-INSTRUCTIONS •• 29
Coding Form. • • • • 7
Continuation Lines • 7 Machine-Instruction Statements • • • 29
Statement Boundaries 8 Instruction Alignment and
Statement Format • • • • • 8 Checking. • • • •••••• • 29
Identification-Sequence Field. 9 Operand Fields and Subfields •• • 29
Summary of Statement Format. 9 Lengths -- Explicit and Implied • 30
Character Set ••••••••••• 10
Machine-Instruction Mnemonic Codes • 31
Assembler Language Structure • • • 10 Machine-Instruction Examples. • 31
RR Format. 31
Terms and Expressions. • 10 RX Format. 32
Terms . . • • • • • • • 10 RS Format. • • • • • • 32
Symbols. • • • • • 10 SI Format. • 32
Self-Defining Terms. • 12 SS Format ••• 32
Location Counter Reference • • 14
Literals • • • • • • • • • 14 Extended Mnemonic Codes. 32
Symbol Length Attribute
Reference • • • • • • • • 15 SECTION 5: ASSEMBLER INSTRUCTION
Terms in Parentheses. • 16 STATEMENTS. • • • • • • • • • 35
Expressions • • • • • • • • • • • 16
Evaluation of Expressions. • • 16 Symbol Definition Instruction. • • • 35
Absolute and Relocatable EQU -- EQUATE SYMBOL. • • • • • 35
Expressions • • • • • • • • • 17
Operation Code Definition Instruction. 36
SECTION 3: ADDRESSING -- PROGRAM OPSYN -- EQUATE OPERATION CODE . . . 36
SECTIONING AND LINKING. • .19 Data Definition Instructions • • • • • • 36
DC -- DEFINE CONSTANT • • • • • • • • 36
Addressing • • • • . • • • • 19 Operand Subfield 1: DUplication
Addresses -- Explicit and Implied. • 19 Factor. • • • • • • • 0 • •• 38
Base Register Instructions ••• • 19 Operand Subfield 2: Type. •• 38
USING -- Use Base Address Operand Subfield 3: Modifiers. 38
Register. • • • • • • • • • • 19 Operand Subfield 4: Constant • 41
DROP -- Drop Base Register • • 20 DS -- Define Storage. • • • • • • • • 48
Programming with the USING Special Uses of the Duplication
Instruction. • • • • 21 Factor. • • • • • • • • • • 50
Relative Addressing • • • • • • 21 CCW -- Define Channel Command Word. • 50
Program Sectioning and Linking • • • 22 Listing Control Instructions . • 51
Control Sections •••••• • 22 TITLE Identify Assembly Output 51
Control Section Location EJECT Start New Page 52
Assignment ••••••• • 22 SPACE Space Listing. 52
First Control section • • • • 23 PRINT Print Optional Data. • 52
START -- Start Assembly. • • • 23
iii
Program Control Instructions . .. .53 Inner Macro Instructions . . 73
ICTL -- Input Format Control ..... 53
ISEQ -- Input Sequence Checking ... 54 Levels of Macro Instructions 74
a
PUNCH -- Punch Card . . . .. .54
REPRO -- Reproduce Following Card .. 55 SECTION 9: HOW TO WRITE CONDI'l'IONAL
ORG -- Set Location Counter ..... 55 ASSEMBLY INSTRUCTIONS . 75
LTORG -- Begin Literal Pool ..... 55
Special Addressing Consideration .56 SET Symbols ..... . • • 75
Duplicate Literals ........ 56 Defining SET Symbols . • 75
CNOP -- Conditional No Operation ... 56 Using Variable Symbols . • • • • • 75
COpy -- Copy Predefined Source
Coding . . . . . . . . . . • .57 Attributes . . . . . . . . . . 76
END End Assembly . . . ... 58 Type Attribute (T'). ... . . 77
Length (L'), Scaling (S'), and
PART 2 -- THE MACRO LANGUAGE
Integer (I') Attributes. . 78
SECTION 6: INTRODUCTION TO THE MACRO Count Attribute (K') • 78
LANGUAGE. .61 Number Attribute (NI ). • • 79
Assigning Attributes to Symbols .. 79
The Macro Instruction Statement. .61
The Macro Definition .61 Sequence Symbols . . . . . · 80
The Macro Library .. · .61 LCLA,LCLB,LCLC -- Define SET Symbols . . 81
System & Programmer Macro Definitions .. 62 SETA -- Set Arithmetic . 81
Evaluation of Arithmetic
System Macro Instructions. . . .. .62
Expressions . . . 82
Varying the Generated Statements .62 Using SETA Symbols . · 82
Variable Symbols ............ 62 SETC -- Set Character ... • 83
Types of Variable Symbols.. .62 Type Attribute . . 83
Assigning Values to Variable Character Expression . . • • 83
Symbols . . . . . . . . . . . . .63 Substring Notation . 84
Global SET Symbols .. ....63 Using SETC Symbols . · 85
Organization of this Part of the SETB -- Set Binary . . . . . · 86
Publication . . . .. . ... 63 Evaluation of Logical
Expressions . . . . • • 87
SECTION 7: HOW TO PREPARE MACRO Using SETB Symbols . . 87
DEFINITIONS . .... . .65
AIF Conditiona+ Branch. 88
MACRO -- Macro Definition Header . .65
AGO Unconditional Branch. • • • • 89
MEND -- Macro Definition Trailer .... 65
ACTR -- Conditional Assembly Loop
Macro Instruction Prototype .. · .65 Counter . . . . . . . . . . . • • 89
Statement Format . . . . . . . 66
ANOP -- Assembly No Operation. . . . . . 90
Model Statements . . . · .66
Conditional Assembly Elements. • •• 90
Symbolic Parameters. . . .67
Concatenating Symbolic SECTION 10: EXTENDED FEATURES OF THE
Parameters with Other MACRO LANGUAGE. . . . . . . . . 93
Characters or Other Symbolic
Parameters .. .68 MEXIT Macro Definition Exit 93
Comments Statements. • .69
MNOTE Request for Error Message 93
COpy Statements ... · .69
Global and Local Variable Symbols. • 94
SECTION 8: HOW TO WRITE MACRO Defining Local and Global SET
INSTRUCTIONS ... · .71 Symbols . . • • 95
Using Global and Local SET
Macro Instruction Operands . · .71 Symbols . . . . . . . . 95
Subscripted SET Symbols .. • • 97
Statement Format . ••• 72
SYSTEM VARIABLE SYMBOLS. . .. . .. 98
Omitted Operands . • .72 &SYSNDX -- Macro Instruction
Index . . . . . . . . . .. . 98
Operand Sublists . . · .72
iv
&SYSECT -- Current Control APPENDIX C: MACHINE-INSTRUCTION FORMAT.119
Section . . . . . . . .. . 99
&SYSLIST -- Macro Instruction APPENDIX D: MACHINE-INSTRUCTION
Operand. . . .. . .... 100 MNEMONIC OPERATION CODES .... .. 121
Keyword Macro Definitions And APPENDIX E: ASSEMBLER INSTRUCTIONS. .131
Instructions . . . . . . . . .. 100
Keyword Prototype ... .101 APPENDIX F: SUMMARY OF CONSTANTS. .135
Keyword Macro Instruction. . .. 101
APPENDIX G: MACRO LANGUAGE SUMMARY. .137
Mixed-Mode Macro Definitions and
.
Instructions ..•.•..•..... 103 APPENDIX H: SAMPLE PROGRAM. .141
Mixed-Mode Prototype ...... 103
Mixed-Mode Macro Instruction •. 103 APPENDIX I: ASSEMBLER LANGUAGES--
FEATURES COMPARISON CHART .145
Macro Definition Compatibility .•... 104
APPENDIX J: SAMPLE MACRO DEFINITIONS .. 149
APPENDIXES
INDEX .. .151
APPENDIX A: CHARACTER CODES •.•... 107
APPENDIX B: HEXADECIMAL-DECIMAL
NUMBER CONVERSION TABLE ....•... 113
V'
ILLUSTRATIONS
figures
Figure 2-1. Coding Form 7 Figure 5-2. Bit-Length Specification
F'igure 2-2. Punched Card Form 8 (Single Constant) . . . . . 39
Figure 2-3. Assembler Language Figure 5-3. Bit-Length Specification
Structure--Machine and (Multiple Constants) .... 40
Assembler Instructions. .11 Figure 5-4. Bit-Length Specification
F'igure 3-l. Multiple Base Register (Multiple Operands) . . . . 40
Assignment. .21 Figure 5-5. Floating-Point External
Figure 4-1. Extended Mnemonic Codes .33 Formats . . .. .... 45
Figure 5-1. Type Codes for Constants. .38 Figure 5-6. CNOP Alignment. . . . . . . 57
Tables
'rable 4-1. Address Specification Table 4-2. Details of Length Specifi
Details .........• 30 cations in SS Instructions. 31
vi
SUMMARY OF AMENDMENTS
FOR GC28-6514-8
OS RELEASE 21
USE OF DSECT SYMBOLS IN ADCONS &SYSLIST
The use of DSECT symbols as absolute An explanation of &SYSLIST(O) has been
expressions in adcons has been rewritten added for completeness.
for clarification.
COMMENTS ON ASSEMBLER INSTRUCTIONS
A note has been added explaining why
HEXADECIMAL CONSTANTS AND SYNTAX RULES certain assembler instructions (e.g.,LTORG)
are not flagged when an "operand" is
Clarification of the syntax restriction present.
on the number of hexadecimal digits allow
able per explicit hexadecimal constant POSITIONAL PARAMETERS
specification has been added.
A note has been added explaining that
positional parameters cannot be changed
to keywords by substitution.
MACHINE-INSTRUCTION ON MNEMONIC
OPERATION CODES
MACRO SEQUENCE SYMBOLS
Erroneous instruction names, condition
code settings, and operand formats contained An explanatory note has been added dis
in Appendix D have been corrected. tinguishing the "name field" of a macro
from the name field parameter.
CHARACTER CODE GRAPHICS TITLE CHANGES
The EBCDIC printer graphics for the IBM Cross-references to OS publications
System/360 8-bit code have been added to have been changed to reflect their new
Appendix A. titles.
vii
PART I -- THE ASSEMBLER LANGUAGE
SECTION 1: INTRODUCTION
SECTION 2: GENERAL INFORMATION
SECTION 3: ADDRESSING AND PROGRAM SECTIONING AND LINKING
SECTION 4: MACHINE INSTRUCTIONS
SECTION 5: ASSEMBLER INSTRUCTIONS
SECTION 1: INTRODUCTION
computer programs may be expressed in THE ASSEMBLER LANGUAGE
machine language, i.e., language directly
interpreted by the computer, or in a sym
bolic language, which is much more mean1ng The basis of the assembler language is a
ful to the programmer. The symbolic lan collection of mnemonic symbols which rep
guage, however, must be translated into resent:
machine language before the computer can
execute the program. This fUnction is 1. System/360 machine-language operation
accomplished by a processing program. codes.
2. Operations (auxiliary functions) to be
Of the various symbolic programming lan performed by the assembler program.
guages, assembler languages are closest to
machine language in form and content. The The language is augmented by other sym
assembler language discussed in this manual bols, supplied by the programmer, and used
is a symbolic programming language for the to represent storage addresses or data.
IBM System/360. It enables the programmer Symbols are easier to remember and code
to use all IBM System/360 machine func than their machine-language equivalents.
tions, as if he were coding in System/360 Use of symbols greatly reduces programming
machine language. effort and error.
The programmer may also create a type of
The assembler program that processes the instruction called a macro instruction. A
language translates symbolic instructions mnemonic symbol, supplied by the program
into machine-language instructions, assigns mer, serves as the operation code of the
storage locations" and perf orms auxiliary instruction.
functions necessary to produce an executa
ble machine-language program.
Machine Operation Codes
The assembler language provides mnemonic
Compatibility machine-instruction operation codes for all
machine ins'tructions in the IBM System/360
Universal Instruction Set and extended mne
System/360 Operating System assemblers monic operation codes for the conuitional
process source programs written in the branch instruction.
Basic Programming Support/360 basic assem
bler language, the IBM 7090/7094 Support
Package for IBM System/360 assembler lan
guage, the Basic Programming Support Ass Assembler Operation Codes
embler (8K Tape) language, the Basic Oper
ating System Assembler (8K Disk) language,
and the Disk and Tape Systems Assembler The assembler language also contains
language, with the following exceptions: mnemonic assembler-instruction operation
codes, used to specify auxiliary functions
to be performed by the assembler. These
1. The XFR assembler instruction is con are instructions to the assembler program
sidered an invalid mnemonic operation itself and, with a few exceptions, result
code by Operating System/360 assem in the generation of no machine-language
blers. code by the assembler program.
2. The assignment, size, and ordering of
literal pools may differ among the Macro Instructions
assemblers.
Differences in the macro language for The assembler language enables the pro-
System/360 assemblers are described in Sec grammer to define and use macro
tion 10 of this publication. instructions.
Section 1: Introduction 3
Macro instruct~ons are represented by an The amount of main storage allocated to
operation code which stands for a sequence the assembler for use during processing
of machine and/or assembler instructions. determines the maximum number of certain
Macro instructions used in preparing an language elements that may be present in
assembler language source program fall into the source program.
two categories: system macro instructions,
provided by IBM, which relate the object
program to components of the operating
system; and macro instructions created by PROGRAMMER AIDS
the programmer specifically for use in the
program at hand, or for incorporation in a
library, available for future use. The assembler provides auxiliary fUnc
tions that assist the programmer in check
Programmer-created macro instructions ing and documenting programs, in controll
are used to simplify the writing of a ing address assignment, in segmenting a
program and to ensure that a standard program, in data and symbol definition, in
sequence of instructions is used to generating macro instructions, and in con
accomplish a desired function. For trolling the assembler itself. Mnemonic
instance, the logic of a program may operation codes for these functions are
require the same instruction sequence to be provided in the language.
executed again and again. Rather than code
this entire sequence each time it is need
ed, the programmer creates a macro Variety in Data Representation: Decimal,
instruction to represent the sequence and binary, hexadecimal, or character represen
then, each time the sequence is needed, the tation of machine-language binary values
programmer simply codes the macro may be employed by the programmer in writ
instruction statement. During assembly, ing source statements. The prograrr@er se
the sequence of instructions represented by lects the representation best suited to his
the macro instruction is inserted in the purpose.
object program ..
Part II of this publication discusses Base Register Address Calculation: As dis
the language and procedures for defining cussed in IBM System/360: Principles of
and using macro instructions. Operation, the Systern/360 addressing scheme
requires the designation of a base register
(containing a base address value) and a
displacement value in specifying a storage
THE ASSEMBLER PROGRAM location. The assembler assumes the cleri
cal burden of calculating storage addresses
in these terms for the symbolic addresses
The assembler program, also referred to used by the programmer. The programmer
as the "assembler," processes the source retains control of base register usage and
statements written in the assembler the values entered therein.
language.
Relocatability: The object programs pro
duced by the assembler are in a format
Basic Functions enabling relocation from the originally
aSSigned storage area to any other suitable
area.
Processing involves the translation of
source statements into machine language,
the assignment of storage locations to Sectioning and Linkin~ The assembler lan
instructions and other elements of the guage and program provide facilities for
program, and t~he performance of the auxil partitioning an assembly into one or more
iary assembler functions deSignated by the parts called control sections. Control
programmer. The output of the assembler sections may be added or deleted when
program is the object program, a machine loading the object program. Because con
language translation of the source program. trol sections do not have to be loaded
The assembler furnishes a printed listing contiguously in storage, a sect.ioned pro
of the source statements and object program gram may be loaded and executed even though
statements and additional information a continuous block of storage large enough
useful to the programmer in analyzing his to accommodate the entire program may not
program, such as error Indications. The be available.
object program is in the format required by
the linkage editor component of Operating The assembler allows symbols to be
Systerrv360. (See the linkage editor publi defined in one assembly and referred to in
ca·tion. ) another, thus effecting a link between
4