book

Write Great Code

by Randall Hyde

November 2004

Intermediate to advanced

456 pages

15h 57m

English

No Starch Press

Read now

Unlock full access

1.1 The Write Great Code Series1.2 What This Volume Covers1.3 Assumptions This Volume Makes1.4 Characteristics of Great Code1.5 The Environment for This Volume1.6 For More Information
2.1 What Is a Number?2.2 Numbering Systems2.2.1 The Decimal Positional Numbering System2.2.2 Radix (Base)2.2.3 The Binary Numbering System2.2.3.1 Converting Between Decimal and Binary Representation2.2.3.2 Making Binary Numbers Easier to Read2.2.3.3 Binary Representation in Programming Languages2.2.4 The Hexadecimal Numbering System2.2.4.1 Hexadecimal Representation in Programming Languages2.2.4.2 Converting Between Hexadecimal and Binary Representations2.2.5 The Octal (Base-8) Numbering System2.2.5.1 Octal Representation in Programming Languages2.2.5.2 Converting Between Octal and Binary Representation2.3 Numeric/String Conversions2.4 Internal Numeric Representation2.4.1 Bits2.4.2 Bit Strings2.5 Signed and Unsigned Numbers2.6 Some Useful Properties of Binary Numbers2.7 Sign Extension, Zero Extension, and Contraction2.8 Saturation2.9 Binary-Coded Decimal (BCD) Representation2.10 Fixed-Point Representation2.11 Scaled Numeric Formats2.12 Rational Representation2.13 For More Information
3.1 Arithmetic Operations on Binary and Hexadecimal Numbers3.1.1 Adding Binary Values3.1.2 Subtracting Binary Values3.1.3 Multiplying Binary Values3.1.4 Dividing Binary Values3.2 Logical Operations on Bits3.3 Logical Operations on Binary Numbers and Bit Strings3.4 Useful Bit Operations3.4.1 Testing Bits in a Bit String Using AND3.4.2 Testing a Set of Bits for Zero/Not Zero Using AND3.4.3 Comparing a Set of Bits Within a Binary String3.4.4 Creating Modulo-n Counters Using AND3.5 Shifts and Rotates3.6 Bit Fields and Packed Data3.7 Packing and Unpacking Data3.8 For More Information
4.1 Introduction to Floating-Point Arithmetic4.2 IEEE Floating-Point Formats4.2.1 Single-Precision Floating-Point Format4.2.2 Double-Precision Floating-Point Format4.2.3 Extended-Precision Floating-Point Format4.3 Normalization and Denormalized Values4.4 Rounding4.5 Special Floating-Point Values4.6 Floating-Point Exceptions4.7 Floating-Point Operations4.7.1 Floating-Point Representation4.7.2 Floating-Point Addition and Subtraction4.7.3 Floating-Point Multiplication and Division4.7.3.1 Floating-Point Multiplication4.7.3.2 Floating-Point Division4.8 For More Information
5.1 Character Data5.1.1 The ASCII Character Set5.1.2 The EBCDIC Character Set5.1.3 Double-Byte Character Sets5.1.4 The Unicode Character Set5.2 Character Strings5.2.1 Character String Formats5.2.1.1 Zero-Terminated Strings5.2.1.2 Length-Prefixed Strings5.2.1.3 Seven-Bit Strings5.2.1.4 HLA Strings5.2.1.5 Descriptor-Based Strings5.2.2 Types of Strings: Static, Pseudo-Dynamic, and Dynamic5.2.2.1 Static Strings5.2.2.2 Pseudo-Dynamic Strings5.2.2.3 Dynamic Strings5.2.3 Reference Counting for Strings5.2.4 Delphi/Kylix Strings5.2.5 Creating Your Own String Formats5.3 Character Sets5.3.1 Powerset Representation of Character Sets5.3.2 List Representation of Character Sets5.4 Designing Your Own Character Set5.4.1 Designing an Efficient Character Set5.4.2 Grouping the Character Codes for Numeric Digits5.4.3 Grouping Alphabetic Characters5.4.4 Comparing Alphabetic Characters5.4.5 Other Character Groupings5.5 For More Information
6.1 The Basic System Components6.1.1 The System Bus6.1.1.1 The Data Bus6.1.2 The Address Bus6.1.3 The Control Bus6.2 Physical Organization of Memory6.2.1 8-Bit Data Buses6.2.2 16-Bit Data Buses6.2.3 32-Bit Data Buses6.2.4 64-Bit Buses6.2.5 Small Accesses on Non-80x86 Processors6.3 Big Endian Versus Little Endian Organization6.4 The System Clock6.4.1 Memory Access and the System Clock6.4.2 Wait States6.4.3 Cache Memory6.5 CPU Memory Access6.5.1 The Direct Memory Addressing Mode6.5.2 The Indirect Addressing Mode6.5.3 The Indexed Addressing Mode6.5.4 The Scaled Indexed Addressing Modes6.6 For More Information
7.1 Pointer Types7.1.1 Pointer Implementation7.1.2 Pointers and Dynamic Memory Allocation7.1.3 Pointer Operations and Pointer Arithmetic7.1.3.1 Adding an Integer to a Pointer7.1.3.2 Subtracting an Integer from a Pointer7.1.3.3 Subtracting a Pointer from a Pointer7.1.3.4 Comparing Pointers7.2 Arrays7.2.1 Array Declarations7.2.2 Array Representation in Memory7.2.3 Accessing Elements of an Array7.2.4 Multidimensional Arrays7.2.4.1 Row-Major Ordering7.2.4.2 Column-Major Ordering7.2.4.3 Declaring Multidimensional Arrays7.2.4.4 Accessing Elements of a Multidimensional Array7.3 Records/Structures7.3.1 Records in Pascal/Delphi7.3.2 Records in C/C++7.3.3 Records in HLA7.3.4 Memory Storage of Records7.4 Discriminant Unions7.4.1 Unions in C/C++7.4.2 Unions in Pascal/Delphi/Kylix7.4.3 Unions in HLA7.4.4 Memory Storage of Unions7.4.5 Other Uses of Unions7.5 For More Information
8.1 Boolean Algebra8.1.1 The Boolean Operators8.1.2 Boolean Postulates8.1.3 Boolean Operator Precedence8.2 Boolean Functions and Truth Tables8.3 Function Numbers8.4 Algebraic Manipulation of Boolean Expressions8.5 Canonical Forms8.5.1 Sum of Minterms Canonical Form and Truth Tables8.5.2 Deriving the Sum of Minterms Canonical Form Algebraically8.5.3 Product of Maxterms Canonical Form8.6 Simplification of Boolean Functions8.7 What Does This Have to Do with Computers, Anyway?8.7.1 Correspondence Between Electronic Circuits and Boolean Functions8.7.2 Combinatorial Circuits8.7.2.1 Addition Circuits8.7.2.2 Seven-Segment LED Decoders8.7.2.3 Decoding Memory Addresses8.7.2.4 Decoding Machine Instructions8.7.3 Sequential and Clocked Logic8.7.3.1 The Set/Reset Flip-Flop8.7.3.2 The D Flip-Flop8.8 For More Information

9.1 Basic CPU Design9.2 Decoding and Executing Instructions: Random Logic Versus Microcode9.3 Executing Instructions, Step by Step9.3.1 The mov Instruction9.3.2 The add Instruction9.3.3 The jnz Instruction9.3.4 The loop Instruction9.4 Parallelism — The Key to Faster Processing9.4.1 The Prefetch Queue9.4.1.1 Saving Fetched Bytes9.4.1.2 Using Unused Bus Cycles9.4.1.3 Overlapping Instructions9.4.1.4 Summary of Background Prefetch Events9.4.2 Conditions That Hinder the Performance of the Prefetch Queue9.4.3 Pipelining — Overlapping the Execution of Multiple Instructions9.4.3.1 A Typical Pipeline9.4.3.2 Stalls in a Pipeline9.4.4 Instruction Caches — Providing Multiple Paths to Memory9.4.5 Pipeline Hazards9.4.6 Superscalar Operation — Executing Instructions in Parallel9.4.7 Out-of-Order Execution9.4.8 Register Renaming9.4.9 Very Long Instruction Word (VLIW) Architecture9.4.10 Parallel Processing9.4.11 Multiprocessing9.5 For More Information
10.1 The Importance of the Design of the Instruction Set10.2 Basic Instruction Design Goals10.2.1 Choosing Opcode Length10.2.2 Planning for the Future10.2.3 Choosing Instructions10.2.4 Assigning Opcodes to Instructions10.3 The Y86 Hypothetical Processor10.3.1 Y86 Limitations10.3.2 Y86 Instructions10.3.2.1 The mov Instruction10.3.2.2 Arithmetic and Logical Instructions10.3.2.3 Control Transfer Instructions10.3.2.4 Miscellaneous Instructions10.3.3 Addressing Modes on the Y8610.3.4 Encoding Y86 Instructions10.3.4.1 Eight Generic Y86 Instructions10.3.4.2 Using the Special Expansion Opcode10.3.5 Examples of Encoding Y86 Instructions10.3.5.1 The add Instruction10.3.5.2 The mov Instruction10.3.5.3 The not Instruction10.3.5.4 The Jump Instructions10.3.5.5 The Zero-Operand Instructions10.3.6 Extending the Y86 Instruction Set10.4 Encoding 80x86 Instructions10.4.1 Encoding Instruction Operands10.4.2 Encoding the add Instruction — Some Examples10.4.3 Encoding Immediate Operands10.4.4 Encoding 8-, 16-, and 32-Bit Operands10.4.5 Alternate Encodings for Instructions10.5 Implications of Instruction Set Design to the Programmer10.6 For More Information
11.1 The Memory Hierarchy11.2 How the Memory Hierarchy Operates11.3 Relative Performance of Memory Subsystems11.4 Cache Architecture11.4.1 Direct-Mapped Cache11.4.2 Fully Associative Cache11.4.3 n-Way Set Associative Cache11.4.4 Matching the Caching Scheme to the Type of Data Access11.4.5 Cache Line Replacement Policies11.4.6 Writing Data to Memory11.4.7 Cache Use and Software11.5 Virtual Memory, Protection, and Paging11.6 Thrashing11.7 NUMA and Peripheral Devices11.8 Writing Software That Is Cognizant of the Memory Hierarchy11.9 Run-Time Memory Organization11.9.1 Static and Dynamic Objects, Binding, and Lifetime11.9.2 The Code, Read-Only, and Constant Sections11.9.3 The Static Variables Section11.9.4 The Uninitialized Storage (BSS) Section11.9.5 The Stack Section11.9.6 The Heap Section and Dynamic Memory Allocation11.9.6.1 Memory Allocation11.9.6.2 Garbage Collection11.9.6.3 The OS and Memory Allocation11.9.6.4 Heap Memory Overhead11.10 For More Information
12.1 Connecting a CPU to the Outside World12.2 Other Ways to Connect Ports to the System12.3 I/O Mechanisms12.3.1 Memory-Mapped I/O12.3.2 I/O and the Cache12.3.3 I/O-Mapped Input/Output12.3.4 Direct Memory Access (DMA)12.4 I/O Speed Hierarchy12.5 System Buses and Data Transfer Rates12.5.1 Performance of the PCI Bus12.5.2 Performance of the ISA Bus12.5.3 The AGP Bus12.6 Buffering12.7 Handshaking12.8 Time-outs on an I/O Port12.9 Interrupts and Polled I/O12.10 Protected Mode Operation and Device Drivers12.10.1 Device Drivers12.10.2 Communicating with Device Drivers and “Files”12.11 Exploring Specific PC Peripheral Devices12.12 The Keyboard12.13 The Standard PC Parallel Port12.14 Serial Ports12.15 Disk Drives12.15.1 Floppy Drives12.15.2 Hard Drives12.15.3 RAID Systems12.15.4 Zip and Other Floptical Drives12.15.5 Optical Drives12.15.6 CD-ROM, CD-R, CR-R/W, DVD, DVD-R, DVD-RAM, and DVD-R/W Drives12.16 Tape Drives12.17 Flash Storage12.18 RAM Disks and Semiconductor Disks12.19 SCSI Devices and Controllers12.20 The IDE/ATA Interface12.21 File Systems on Mass Storage Devices12.21.1 Maintaining Files Using a Free-Space Bitmap12.21.2 File Allocation Tables12.21.3 List-of-Blocks File Organization12.22 Writing Software That Manipulates Data on a Mass Storage Device12.22.1 File Access Performance12.22.2 Synchronous and Asynchronous I/O12.22.3 The Implications of I/O Type12.22.4 Memory-Mapped Files12.23 The Universal Serial Bus (USB)12.23.1 USB Design12.23.2 USB Performance12.23.3 Types of USB Transmissions12.23.4 USB Device Drivers12.24 Mice, Trackpads, and Other Pointing Devices12.25 Joysticks and Game Controllers12.26 Sound Cards12.26.1 How Audio Interface Peripherals Produce Sound12.26.2 The Audio and MIDI File Formats12.26.3 Programming Audio Devices12.27 For More Information

Overview

If you've asked someone the secret to writing efficient, well-written software, the answer that you've probably gotten is "learn assembly language programming." By learning assembly language programming, you learn how the machine really operates and that knowledge will help you write better high-level language code. A dirty little secret assembly language programmers rarely admit to, however, is that what you really need to learn is machine organization, not assembly language programming. Write Great Code Vol I , the first in a series from assembly language expert Randall Hyde, dives right into machine organization without the extra overhead of learning assembly language programming at the same time. And since Write Great Code Vol I concentrates on the machine organization, not assembly language, the reader will learn in greater depth those subjects that are language-independent and of concern to a high level language programmer. Write Great Code Vol I will help programmers make wiser choices with respect to programming statements and data types when writing software, no matter which language they use.