In this book, the word "hacker" is returned to its original meaning - a person who is a passionate, talented programmer, capable of creating extremely efficient and elegant code. The book embodies the author's forty years of experience in the field of compiler development and computer architecture. Here you will find many tricks for working with individual bits, bytes, and calculating various integer functions. Most of the material is accompanied by a strict mathematical justification. Whatever your professionalism, you will definitely find something new for yourself in this book. In addition, the book will make you look at already familiar things from a new perspective. This book will be no less useful for a novice programmer, who can simply use the ready-made tips from the book, applying them in their daily practice.