HLASM: V1R6 Language Ref

ContentsAbout this manual . . . . . . . . . . viiWho should use this manual . . . . . . . . viiProgramming interface information . . . . . . viiOrganization of this manual . . . . . . . . viiiIBM High Level Assembler for z/OS & z/VM &z/VSE Publications . . . . . . . . . . . viiiHardcopy Publications . . . . . . . . . .ixOnline publications . . . . . . . . . . .xRelated publications . . . . . . . . . . . .xSyntax notation . . . . . . . . . . . . .xDouble-byte character set notation . . . . . . . xiiSummary of changes . . . . . . . . xvPart 1. Assemblerlanguage—structure and concepts . . 1Chapter 1. Introduction . . . . . . . . 3Language compatibility . . . . . . . . . . .4Assembler language . . . . . . . . . . . .4Machine instructions . . . . . . . . . . .5Assembler instructions . . . . . . . . . .5Macro instructions . . . . . . . . . . .5Assembler program . . . . . . . . . . . .5Basic functions . . . . . . . . . . . . .6Associated data . . . . . . . . . . . .6Controlling the assembly . . . . . . . . .6Processing sequence . . . . . . . . . . .7Relationship of assembler to operating system . . .7Coding made easier . . . . . . . . . . . .9Symbolic representation of program elements . .9Variety in data representation . . . . . . . .9Controlling address assignment . . . . . . .9Relocatability . . . . . . . . . . . . .9Sectioning a program . . . . . . . . . .9Linkage between source modules . . . . . .9Program listings . . . . . . . . . . . .10Multiple source modules . . . . . . . . .10Chapter 2. Coding and structure . . . . 11Character set . . . . . . . . . . . . . .11Standard character set . . . . . . . . . .11Double-byte character set . . . . . . . . .12Translation table . . . . . . . . . . . .13Assembler language coding conventions . . . . .13Field boundaries . . . . . . . . . . . .14Continuation lines . . . . . . . . . . .15Blank lines . . . . . . . . . . . . .18Comment statement format . . . . . . . .18Instruction statement format . . . . . . . .18Assembler language structure . . . . . . . .20Overview of assembler language structure . . .22Machine instructions . . . . . . . . . .23Assembler instructions . . . . . . . . .24|Conditional assembly instructions . . . . . .25Macro instructions . . . . . . . . . . .26Mnemonic tags . . . . . . . . . . . .26Terms, literals, and expressions . . . . . . . .27Terms . . . . . . . . . . . . . . .27Literals . . . . . . . . . . . . . . .40Expressions . . . . . . . . . . . . .43Chapter 3. Program structures andaddressing . . . . . . . . . . . . . 49Object program structures . . . . . . . . .49Source program structures . . . . . . . . .50Source module . . . . . . . . . . . .51Sections, elements, and parts . . . . . . .51Sections . . . . . . . . . . . . . .52Reference control sections . . . . . . . .55Classes (z/OS and CMS) . . . . . . . . .57Parts (z/OS and CMS) . . . . . . . . . .59Location counter setting . . . . . . . . .60Addressing . . . . . . . . . . . . . .62Addressing within source modules: establishingaddressability . . . . . . . . . . . . .62Base register instructions . . . . . . . . .64Qualified addressing . . . . . . . . . .65Dependent addressing . . . . . . . . . .65Relative addressing . . . . . . . . . . .66Literal pools . . . . . . . . . . . . .66Establishing residence and addressing mode . .66Symbolic linkages . . . . . . . . . . .67External symbol dictionary entries . . . . . .70Summary of source and object programstructures . . . . . . . . . . . . . .71Part 2. Machine and assemblerinstruction statements . . . . . . . 73Chapter 4. Machine instructionstatements . . . . . . . . . . . . . 75General instructions . . . . . . . . . . .75Decimal instructions . . . . . . . . . . .75Floating-point instructions . . . . . . . . .76Control instructions . . . . . . . . . . .76Input/output operations . . . . . . . . . .76Branching with extended mnemonic codes . . . .77Alternative mnemonics for some branch relativeinstructions . . . . . . . . . . . . .80Statement formats . . . . . . . . . . . .80Symbolic operation codes . . . . . . . . . .81Operand entries . . . . . . . . . . . . .82Registers . . . . . . . . . . . . . .83Addresses . . . . . . . . . . . . . .84Lengths . . . . . . . . . . . . . . .86Immediate data . . . . . . . . . . . .87Examples of coded machine instructions . . . . .87© Copyright IBM Corp. 1982, 2008 iii