book

The Art of Assembly Language, 2nd Edition

by Randall Hyde

March 2010

Beginner

760 pages

18h 51m

English

No Starch Press

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First EditionSecond Edition
1.1 The Anatomy of an HLA Program

1.9.1 Boolean Expressions in HLA Statements1.9.2 The HLA if..then..elseif..else..endif Statement1.9.3 Conjunction, Disjunction, and Negation in Boolean Expressions1.9.4 The while..endwhile Statement1.9.5 The for..endfor Statement1.9.6 The repeat..until Statement1.9.7 The break and breakif Statements1.9.8 The forever..endfor Statement1.9.9 The try..exception..endtry Statement
1.10.1 Predefined Constants in the stdio Module1.10.2 Standard In and Standard Out1.10.3 The stdout.newln Routine1.10.4 The stdout.putiX Routines1.10.5 The stdout.putiXSize Routines1.10.6 The stdout.put Routine1.10.7 The stdin.getc Routine1.10.8 The stdin.geti X Routines1.10.9 The stdin.readLn and stdin.flushInput Routines1.10.10 The stdin.get Routine
1.11.1 Nesting try..endtry Statements1.11.2 The unprotected Clause in a try..endtry Statement1.11.3 The anyexception Clause in a try..endtry Statement1.11.4 Registers and the try..endtry Statement
2.1 Numbering Systems2.1.1 A Review of the Decimal System2.1.2 The Binary Numbering System2.1.3 Binary Formats
2.3.1 Bits2.3.2 Nibbles2.3.3 Bytes2.3.4 Words2.3.5 Double Words2.3.6 Quad Words and Long Words
2.12.1 IEEE Floating-Point Formats2.12.2 HLA Support for Floating-Point Values
2.14.1 The ASCII Character Encoding2.14.2 HLA Support for ASCII Characters
3.1 The 80x86 Addressing Modes3.1.1 80x86 Register Addressing Modes3.1.2 80x86 32-Bit Memory Addressing Modes3.1.2.1 The Displacement-Only Addressing Mode3.1.2.2 The Register-Indirect Addressing Modes3.1.2.3 Indexed Addressing Modes3.1.2.4 Variations on the Indexed Addressing Mode3.1.2.5 Scaled-Indexed Addressing Modes3.1.2.6 Addressing Mode Wrap-up
3.2.1 The code Section3.2.2 The static Section3.2.3 The readonly Data Section3.2.4 The storage Section3.2.5 The @nostorage Attribute3.2.6 The var Section3.2.7 Organization of Declaration Sections Within Your Programs
3.8.1 The Basic push Instruction3.8.2 The Basic pop Instruction3.8.3 Preserving Registers with the push and pop Instructions
3.9.1 Other push and pop Instructions3.9.2 Removing Data from the Stack Without Popping It
4.1 Some Additional Instructions: intmul, bound, into
4.2.1 Constant Types4.2.2 String and Character Literal Constants4.2.3 String and Text Constants in the const Section4.2.4 Constant Expressions4.2.5 Multiple const Sections and Their Order in an HLA Program4.2.6 The HLA val Section4.2.7 Modifying val Objects at Arbitrary Points in Your Programs
4.5.1 Using Pointers in Assembly Language4.5.2 Declaring Pointers in HLA4.5.3 Pointer Constants and Pointer Constant Expressions4.5.4 Pointer Variables and Dynamic Memory Allocation4.5.5 Common Pointer Problems
4.22.1 Row-Major Ordering4.22.2 Column-Major Ordering
5.1 Procedures
5.6.1 Pass by Value5.6.2 Pass by Reference
5.7.1 Returning Function Results5.7.2 Instruction Composition in HLA5.7.3 The HLA @returns Option in Procedures
5.17.1 Passing Parameters in Registers5.17.2 Passing Parameters in the Code Stream5.17.3 Passing Parameters on the Stack5.17.3.1 Accessing Value Parameters on the Stack5.17.3.2 Passing Value Parameters on the Stack5.17.3.3 Accessing Reference Parameters on the Stack5.17.3.4 Passing Reference Parameters on the Stack5.17.3.5 Passing Formal Parameters as Actual Parameters5.17.3.6 HLA Hybrid Parameter-Passing Facilities5.17.3.7 Mixing Register and Stack-Based Parameters
5.24.1 Behavior of the external Directive5.24.2 Header Files in HLA
6.1 80x86 Integer Arithmetic Instructions6.1.1 The mul and imul Instructions6.1.2 The div and idiv Instructions6.1.3 The cmp Instruction6.1.4 The setcc Instructions6.1.5 The test Instruction
6.2.1 Simple Assignments6.2.2 Simple Expressions6.2.3 Complex Expressions6.2.4 Commutative Operators
6.4.1 Multiplying without mul, imul, or intmul6.4.2 Division Without div or idiv6.4.3 Implementing Modulo-N Counters with and
6.5.1 FPU Registers6.5.1.1 FPU Data Registers6.5.1.2 The FPU Control Register6.5.1.3 The FPU Status Register6.5.2 FPU Data Types6.5.3 The FPU Instruction Set6.5.4 FPU Data Movement Instructions6.5.4.1 The fld Instruction6.5.4.2 The fst and fstp Instructions6.5.4.3 The fxch Instruction6.5.5 Conversions6.5.5.1 The fild Instruction6.5.5.2 The fist, fistp, and fisttp Instructions6.5.5.3 The fbld and fbstp Instructions6.5.6 Arithmetic Instructions6.5.6.1 The fadd and faddp Instructions6.5.6.2 The fsub, fsubp, fsubr, and fsurpb Instructions6.5.6.3 The fmul and fmulp Instructions6.5.6.4 The fdiv, fdivp, fdivr, and fdivrp Instructions6.5.6.5 The fsqrt Instruction6.5.6.6 The fprem and fprem1 Instructions6.5.6.7 The frndint Instruction6.5.6.8 The fabs Instruction6.5.6.9 The fchs Instruction6.5.7 Comparison Instructions6.5.7.1 The fcom, fcomp, and fcompp Instructions6.5.7.2 The fcomi and fcomip Instructions6.5.7.3 The ftst Instruction6.5.8 Constant Instructions6.5.9 Transcendental Instructions6.5.9.1 The f2xm1 Instruction6.5.9.2 The fsin, fcos, and fsincos Instructions6.5.9.3 The fptan Instruction6.5.9.4 The fpatan Instruction6.5.9.5 The fyl2x Instruction6.5.9.6 The fyl2xp1 Instruction6.5.10 Miscellaneous Instructions6.5.10.1 The finit and fninit Instructions6.5.10.2 The fldcw and fstcw Instructions6.5.10.3 The fclex and fnclex Instructions6.5.10.4 The fstsw and fnstsw Instructions6.5.11 Integer Operations
6.6.1 Converting Arithmetic Expressions to Postfix Notation6.6.2 Converting Postfix Notation to Assembly Language
7.1 Low-Level Control Structures
7.7.1 if..then..else Sequences7.7.2 Translating HLA if Statements into Pure Assembly Languageif( flag_specification ) then stmts endif;if( register ) then stmts endif;if( !register ) then stmts endif;if( boolean_variable ) then stmts endif;if( !boolean_variable ) then stmts endif;if( mem_reg relop mem_reg_const ) then stmts endif;if( reg/mem in LowConst..HiConst ) then stmts endif;if( reg/mem not in LowConst..HiConst ) then stmts endif;7.7.3 Implementing Complex if Statements Using Complete Boolean Evaluation7.7.4 Short-Circuit Boolean Evaluation7.7.5 Short-Circuit vs. Complete Boolean Evaluation7.7.6 Efficient Implementation of if Statements in Assembly Language7.7.6.1 Know Your Data!7.7.6.2 Rearranging Expressions7.7.6.3 Destructuring Your Code7.7.6.4 Calculation Rather Than Branching7.7.7 switch/case Statements
7.10.1 while Loops7.10.2 repeat..until Loops7.10.3 forever..endfor Loops7.10.4 for Loops7.10.5 The break and continue Statementsforever..continue..endforwhile..continue..endwhilefor..continue..endforrepeat..continue..until7.10.6 Register Usage and Loops
7.11.1 Moving the Termination Condition to the End of a Loop7.11.2 Executing the Loop Backwards7.11.3 Loop-Invariant Computations7.11.4 Unraveling Loops7.11.5 Induction Variables
8.1 Multiprecision Operations8.1.1 HLA Standard Library Support for Extended-Precision Operations8.1.2 Multiprecision Addition Operations8.1.3 Multiprecision Subtraction Operations8.1.4 Extended-Precision Comparisons8.1.5 Extended-Precision Multiplication8.1.6 Extended-Precision Division8.1.7 Extended-Precision neg Operations8.1.8 Extended-Precision and Operations8.1.9 Extended-Precision or Operations8.1.10 Extended-Precision xor Operations8.1.11 Extended-Precision not Operations8.1.12 Extended-Precision Shift Operations8.1.13 Extended-Precision Rotate Operations8.1.14 Extended-Precision I/O8.1.14.1 Extended-Precision Hexadecimal Output8.1.14.2 Extended-Precision Unsigned Decimal Output8.1.14.3 Extended-Precision Signed Decimal Output8.1.14.4 Extended-Precision Formatted Output8.1.14.5 Extended-Precision Input Routines8.1.14.6 Extended-Precision Hexadecimal Input8.1.14.7 Extended-Precision Unsigned Decimal Input8.1.14.8 Extended-Precision Signed Decimal Input
8.3.1 Literal BCD Constants8.3.2 The 80x86 daa and das Instructions8.3.3 The 80x86 aaa, aas, aam, and aad Instructions8.3.4 Packed Decimal Arithmetic Using the FPU
8.4.1 Function Computation via Table Lookup8.4.2 Domain Conditioning8.4.3 Generating Tables8.4.4 Table Lookup Performance
9.1 Introduction to the Compile-Time Language (CTL)
9.5.1 Type-Conversion Compile-Time Functions9.5.2 Numeric Compile-Time Functions9.5.3 Character-Classification Compile-Time Functions9.5.4 Compile-Time String Functions9.5.5 Compile-Time Symbol Information9.5.6 Miscellaneous Compile-Time Functions9.5.7 Compile-Time Type Conversions of Text Objects
9.8.1 Standard Macros9.8.2 Macro Parameters9.8.2.1 Standard Macro Parameter Expansion9.8.2.2 Macros with a Variable Number of Parameters9.8.2.3 Required vs. Optional Macro Parameters9.8.3 Local Symbols in a Macro9.8.4 Macros as Compile-Time Procedures9.8.5 Simulating Function Overloading with Macros
9.9.1 Constructing Data Tables at Compile Time9.9.2 Unrolling Loops
10.1 What Is Bit Data, Anyway?
11.1 The 80x86 String Instructions11.1.1 How the String Instructions Operate11.1.2 The rep/repe/repz and repnz/repne Prefixes11.1.3 The Direction Flag11.1.4 The movs Instruction11.1.5 The cmps Instruction11.1.6 The scas Instruction11.1.7 The stos Instruction11.1.8 The lods Instruction11.1.9 Building Complex String Functions from lods and stos
12.1 General Principles
12.8.1 Virtual Method Tables12.8.2 Object Representation with Inheritance
12.9.1 Dynamic Object Allocation Within the Constructor12.9.2 Constructors and Inheritance12.9.3 Constructor Parameters and Procedure Overloading

Content preview from The Art of Assembly Language, 2nd Edition

10.3 The Carry Flag as a Bit Accumulator

The btx, shift, and rotate instructions set or clear the carry flag depending on the operation and selected bit. Because these instructions place their "bit result" in the carry flag, it is often convenient to think of the carry flag as a 1-bit register or accumulator for bit operations. In this section we will explore some of the operations possible with this bit result in the carry flag.

Instructions that will be useful for manipulating bit results in the carry flag are those that use the carry flag as some sort of input value. The following is a sampling of such instructions: