Book Image

Practical WebAssembly

By : Sendil Kumar Nellaiyapen
Book Image

Practical WebAssembly

By: Sendil Kumar Nellaiyapen

Overview of this book

Rust is an open source language tuned toward safety, concurrency, and performance. WebAssembly brings all the capabilities of the native world into the JavaScript world. Together, Rust and WebAssembly provide a way to create robust and performant web applications. They help make your web applications blazingly fast and have small binaries. Developers working with JavaScript will be able to put their knowledge to work with this practical guide to developing faster and maintainable code. Complete with step-by-step explanations of essential concepts, examples, and self-assessment questions, you’ll begin by exploring WebAssembly, using the various tools provided by the ecosystem, and understanding how to use WebAssembly and JavaScript together to build a high-performing application. You’ll then learn binary code to work with a variety of tools that help you to convert native code into WebAssembly. The book will introduce you to the world of Rust and the ecosystem that makes it easy to build/ship WebAssembly-based applications. By the end of this WebAssembly Rust book, you’ll be able to create and ship your own WebAssembly applications using Rust and JavaScript, understand how to debug, and use the right tools to optimize and deliver high-performing applications.
Table of Contents (15 chapters)
1
Section 1: Introduction to WebAssembly
5
Section 2: WebAssembly Tools
9
Section 3: Rust and WebAssembly

Understanding various levels of optimizations

C/C++ programs are compiled and converted into native code via Clang or the GCC compiler. Clang or the GCC compiler converts the C/C++ program based on the target. Target here refers to the end machine where the code is executed. emcc has the Clang compiler built in. The emcc compiler is responsible for converting the C or C++ source code into LLVM byte code.

In this section, we will see how to improve the optimization and code size of the generated WebAssembly binary code.

To improve the efficiency and generated code size, the Emscripten compiler has the following options:

  • Optimizations
  • Closure Compiler

Lets talk about optimizations first.

Optimizations

The goal of the compiler is to reduce the cost of compilation, that is, the compile time. With the -O optimization flag, the compiler tries to improve the code size and/or the performance at the expense of the compile time. In terms of compiler optimizations...