Book Image

The Art of Writing Efficient Programs

By : Fedor G. Pikus
3 (2)
Book Image

The Art of Writing Efficient Programs

3 (2)
By: Fedor G. Pikus

Overview of this book

The great free lunch of "performance taking care of itself" is over. Until recently, programs got faster by themselves as CPUs were upgraded, but that doesn't happen anymore. The clock frequency of new processors has almost peaked, and while new architectures provide small improvements to existing programs, this only helps slightly. To write efficient software, you now have to know how to program by making good use of the available computing resources, and this book will teach you how to do that. The Art of Efficient Programming covers all the major aspects of writing efficient programs, such as using CPU resources and memory efficiently, avoiding unnecessary computations, measuring performance, and how to put concurrency and multithreading to good use. You'll also learn about compiler optimizations and how to use the programming language (C++) more efficiently. Finally, you'll understand how design decisions impact performance. By the end of this book, you'll not only have enough knowledge of processors and compilers to write efficient programs, but you'll also be able to understand which techniques to use and what to measure while improving performance. At its core, this book is about learning how to learn.
Table of Contents (18 chapters)
1
Section 1 – Performance Fundamentals
7
Section 2 – Advanced Concurrency
11
Section 3 – Designing and Coding High-Performance Programs

Performance measurements by example

We will have time to learn about each of the performance analysis tools in more detail in the rest of this chapter, but in this section, we will do a quick end-to-end example and analyze the performance of a simple program. This will show you what the typical performance analysis flow looks like and how different tools are used.

There is also a hidden agenda: by the end of this section, you will come to believe that you should never guess about performance.

Any real-world program that you may have to analyze and optimize is likely to be large enough to take many pages in this book, so we will use a simplified example. This program sorts substrings in a very long string: suppose we have a string S, such as "abcdcba" (this is not so long; our actual strings will have millions of characters). We can have a substring starting from any character in this string, for example, the substring S0 starts with the offset 0 and, therefore, has...