YJIT: Building a New JIT Compiler Inside CRuby

The 1980s and 1990s saw the genesis of Perl, Ruby, Python, PHP and JavaScript: interpreted, dynamically-typed programming languages which favored ease of use and flexibility over performance. In many ways, these programming languages are a product of the surrounding context. The 90s were the peak of the dot-com hype, and CPU clock speeds were still doubling roughly every 18 months. It looked like the growth was never going to end. You didn’t really have to try to make your software run fast, because computers were just going to get faster, and the problem would take care of itself. Today, things are a little different. We’re reaching the limit of current fabrication technologies, we can’t rely on single-core performance increases to solve our performance problems, and because of mobile devices and environmental concerns, we’re starting to realize that energy efficiency matters.