rbf

A JIT compiling brainfuck interpreter written in rust. It's fast!

The interpreter is split into two crates using a workspace:

• rbf: The executable that let's you run brainfuck code
• librbf: This is where all the interpreter code is implemented

The way this interpreter works is:

1. Parse code into an intermediate representation
2. Apply some optimizations
3. Generate code using dynasm-rs
4. Run the generated code

Installation

This project requires rust 1.45.0 or newer.

Using cargo install

$ cargo install https://github.com/lukad/rbf.git

Compiling manually with cargo

$ git clone https://github.com/lukad/rbf.git
$ cd rbf
$ cargo install

Library usage

Add librbf to your depedencies in the Cargo.toml.

[dependencies]
librbf = { git = "https://github.com/lukad/rbf.git" }

Use it in your code.

use librbf::{parse, Jit};

fn main() {
    let source = "++++++++[>++++++++<-]>.".as_bytes();
    let program = parse(source);
    let fun = Jit::new().compile(&program);
    fun.run();
}

Optimizations

The following optimizations are implemented:

• Fusing of adjacent + and - instructions:
  +-++-+ becomes Add(2)
• Fusing of adjacent > and < instructions:
  >><<<<> becomes Move(-1)
• Detection of set loops:
  [-] becomes Set(0)
• Set instructions will be fused with following Add instructions:
  [-]+++ becomes Set(3)
• Detection of multiplication loops:
  [>++++<-] becomes Mul(1, 8), Set(0)
• Detection of scan looops:
  [>>] becomes Scan(2)
• Elimination of code without effects