Hacker’s Delight

“This is the first book that promises to tell the deep, dark secrets of computer arithmetic, and it delivers in spades. It contains every trick I knew plus many, many more. A godsend for library developers, compiler writers, and lovers of elegant hacks, it deserves a spot on your shelf right next to Knuth.”

–Josh Bloch (Praise for the first edition)

In Hacker’s Delight, Second Edition, Hank Warren once again compiles an irresistible collection of programming hacks: timesaving techniques, algorithms, and tricks that help programmers build more elegant and efficient software, while also gaining deeper insights into their craft. Warren’s hacks are eminently practical, but they’re also intrinsically interesting, and sometimes unexpected, much like the solution to a great puzzle. They are, in a word, a delight to any programmer who is excited by the opportunity to improve.

Extensive additions in this edition include

• A new chapter on cyclic redundancy checking (CRC), including routines for the commonly used CRC-32 code
• A new chapter on error correcting codes (ECC), including routines for the Hamming code
• More coverage of integer division by constants, including methods using only shifts and adds
• Computing remainders without computing a quotient
• More coverage of population count and counting leading zeros
• Array population count
• New algorithms for compress and expand
• An LRU algorithm
• Floating-point to/from integer conversions
• Approximate floating-point reciprocal square root routine
• A gallery of graphs of discrete functions
• Now with exercises and answers

Table of Contents

CHAPTER 1. INTRODUCTION

CHAPTER 2. BASICS

CHAPTER 3. POWER-OF-2 BOUNDARIES

CHAPTER 4. ARITHMETIC BOUNDS

CHAPTER 5. COUNTING BITS

CHAPTER 6. SEARCHING WORDS

CHAPTER 7. REARRANGING BITS AND BYTES

CHAPTER 8. MULTIPLICATION

CHAPTER 9. INTEGER DIVISION

CHAPTER 10. INTEGER DIVISION BY CONSTANTS

CHAPTER 11 . SOME ELEM ENT ARY FUNCTIONS

CHAPTER 12. UNUSUAL BASES FOR NUMBER SYSTEMS

CHAPTER 13. GRAY CODE

CHAPTER 14. CYCLIC REDUNDANCY CHECK

CHAPTER 15. ERROR-CORRECTING CODES

CHAPTER 16. HILBERT’S CURVE

CHAPTER 17. FLOATING-POINT

CHAPTER 18. FORMULAS FOR PRIMES

About the Author

Henry S. Warren, Jr., has had a fifty-year career with IBM, spanning from the IBM 704 to the PowerPC and beyond. He has worked on various military command and control systems and on the SETL (SET Language) project under Jack Schwartz. Since 1973, Hank has been with IBM’s Research Division, focusing on compilers and computer architectures. He currently works on a supercomputer project aimed at an exaflop. Hank received his Ph.D. in computer science from the Courant Institute at New York University.