Ruby Lands "YJIT" As A Speedy, In-Process JIT Compiler

Written by Michael Larabel in Programming on 21 October 2021 at 12:00 AM EDT. 19 Comments
The Ruby programming language implementation has merged YJIT, its new just-in-time (JIT) compiler.

YJIT is a JIT compiler for Ruby that leverages the lazy Basic Block Versioning (LBBV) architecture. YJIT has been in the works for a number of years. Most exciting for end-users and developers is that YJIT yields an average speed-up of around 23% compared to the current CRuby interpreter for realistic benchmarks.

With Ruby 3.1 the plan is to include it as a preview release to help test it and enjoy the performance gains, but it is currently disabled by default. The "--yjit" or "YJIT_RUBY_ENABLE=1" options are needed to currently enable this Ruby JIT. YJIT additionally supports just Linux and macOS platforms so far on x86-64 CPUs. Unsupported platforms will see the conventional Ruby interpreter used.

More details on Ruby's YJIT that was merged on Wednesday can be found via its merge request.
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