Compiling the Web - Building a Just-in-Time Compiler for JavaScript

Опубликовано 6 сентября 2016, 18:03

Over the last decade we have made great strides towards improving the execution performance of virtual-machine (VM) based high level programming languages. Today, dynamic compilation is standard in most Java and C# VMs, enabling programs written in these languages to execute with similar efficiency as legacy type-unsafe C or assembly code. However, for the past decade much of the research and development effort in the Just-in-Time compilation domain was focused on the runtime compilation of statically typed languages, leaving an important and steadily growing field of programming languages behind: dynamically typed high level languages such as JavaScript, Python, PHP and Ruby. Combined with an explosive growth of web applications and the wide-spread use of dynamically typed programming languages for the client and server side of such web applications, this has created a situation where bytecode interpretation is suddenly again the predominant mode of execution for much of the code used on a daily basis on desktop computers, including popular web programs and services like Google Mail or Google Docs. In this talk I will report on the design and development of TraceMonkey, the JavaScript Just-in-Time compiler in Mozilla's Firefox web browser. I will discuss the fundamental differences between statically typed and dynamically typed languages from the perspective of a compiler constructor, and I will highlight some of the unique challenges for compiling dynamically typed languages such as JavaScript.