2.8 KiB
MicroJIT (uJIT)
DISCLAIMER: Please note that this project is in early stages of development. It is very much a work in progress, it may cause your software to crash, and current performance results are likely to leave you feeling unimpressed.
MicroJIT is a lightweight, minimalistic Ruby JIT built inside the CRuby/MRI binary. It lazily compiles code using a Basic Block Versioning (BBV) architecture. The target use case is that of servers running Ruby on Rails, an area where CRuby's MJIT has not yet managed to deliver speedups. To simplify development, we currently support only MacOS and Linux on x86-64, but an ARM64 backend is part of future plans. This project is open source and falls under the same license as CRuby.
If you would like to learn more about BBV, there are two published papers, and associated conference talks:
- Simple and Effective Type Check Removal through Lazy Basic Block Versioning (ECOOP 2015 talk)
- Interprocedural Type Specialization of JavaScript Programs Without Type Analysis (ECOOP 2016 talk)
Installation
Start by cloning the microjit
branch of the Shopify/ruby
repository:
git clone https://github.com/Shopify/ruby.git microjit
cd microjit
git checkout microjit
The uJIT ruby
binary can be built with either GCC or Clang. We recommend enabling debug symbols so that assertions are enabled:
autoconf
./configure cppflags=-DRUBY_DEBUG --prefix=$HOME/.rubies/ruby-microjit
make -j16 install
You can test that uJIT works correctly by running:
# Quick tests found in /bootstraptest
make btest
# Complete set of tests
make -j16 test-all
Once uJIT is built, you can either use ./miniruby
from within your build directory, or switch to the uJIT version of ruby
by using the chruby
tool:
chruby ruby-microjit
Source Code Organization
The uJIT source code is divided between:
ujit_asm.c
: x86 in-memory assembler we use to generate machine codeujit_codegen.c
: logic for translating Ruby bytecode to machine codeujit_core.c
: basic block versioning logic, core structure of uJITujit_iface.c
: code uJIT uses to interface with the rest of CRubyujit.rb
:UJIT
module that is exposed to Ruby code
The core of CRuby's interpreter logic is found in:
insns.def
: defines Ruby's bytecode instructionsvm_insnshelper.c
: logic used by Ruby's bytecode instructionsvm_exec.c
: Ruby interpreter loop
Contributing
We welcome open source contributors. If you are interested in contributing to this project, please contact Maxime Chevalier (@Love2Code) via twitter.