High Level Assembler for z/OS & z/VM & z/VSE 1.6 Language Reference IBM SC26-4940-09 Note Before using this information and the product it supports, be sure to read the general information under “Notices” on page 371. This edition applies to IBM High Level Assembler for z/OS & z/VM & z/VSE, Release 6, Program Number 5696-234 and to any subsequent releases until otherwise indicated in new editions. Make sure that you are using the correct edition for the level of the product. Order publications through your IBM® representative or the IBM branch office serving your locality. IBM welcomes your comments. For information on how to send comments, see “How to send your comments to IBM” on page xxv. © Copyright International Business Machines Corporation 1992, 2021. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Figures................................................................................................................. xi Tables..................................................................................................................xv About this document...........................................................................................xix Who should use this manual..................................................................................................................... xix Programming interface information..........................................................................................................xix Organization of this manual.......................................................................................................................xix High Level Assembler documentation....................................................................................................... xx Publications...........................................................................................................................................xx Related publications............................................................................................................................ xxi Syntax notation..........................................................................................................................................xxi Format................................................................................................................................................ xxiii How to send your comments to IBM.................................................................... xxv If you have a technical problem............................................................................................................... xxv Summary of changes........................................................................................ xxvii Chapter 1. Introduction......................................................................................... 1 Language compatibility................................................................................................................................1 Assembler language.....................................................................................................................................2 Machine instructions.............................................................................................................................. 2 Assembler instructions...........................................................................................................................2 Macro instructions.................................................................................................................................. 2 Assembler program......................................................................................................................................3 Basic functions....................................................................................................................................... 3 Associated data...................................................................................................................................... 3 Controlling the assembly........................................................................................................................3 Processing sequence..............................................................................................................................4 Relationship of assembler to operating system..........................................................................................5 Coding made easier......................................................................................................................................6 Symbolic representation of program elements.....................................................................................6 Variety in data representation................................................................................................................6 Controlling address assignment.............................................................................................................6 Relocatability.......................................................................................................................................... 6 Sectioning a program..............................................................................................................................7 Linkage between source modules......................................................................................................... 7 Program listings......................................................................................................................................7 Multiple source modules........................................................................................................................7 Double-byte character set notation............................................................................................................ 7 Chapter 2. Coding and structure.............................................................................9 Character set................................................................................................................................................9 Standard character set...........................................................................................................................9 Double-byte character set................................................................................................................... 10 Using EBCDIC characters and double-byte characters...................................................................... 10 Translation table...................................................................................................................................12 Assembler language coding conventions..................................................................................................12 iii Field boundaries...................................................................................................................................12 Continuation lines.................................................................................................................................13 Blank lines............................................................................................................................................ 16 Comment statement format................................................................................................................ 16 Instruction statement format.............................................................................................................. 16 Assembler language structure.................................................................................................................. 18 Overview of assembler language structure......................................................................................... 19 Machine instructions............................................................................................................................ 20 Assembler instructions........................................................................................................................ 21 Conditional assembly instructions.......................................................................................................22 Macro instructions................................................................................................................................23 Mnemonic tags..................................................................................................................................... 23 Terms, literals, and expressions................................................................................................................24 Terms.................................................................................................................................................... 24 Literals.................................................................................................................................................. 37 Expressions.......................................................................................................................................... 40 Chapter 3. Program structures and addressing..................................................... 45 Object program structures.......................................................................................................................