jiniux / brainfuck_interpreter

My attempt to create a Brainfuck interpreter in C.

Brainfuck interpreter

Optimized lightweight Brainfuck interpreter made in C (needless to say: from scratch).

Build

It requires The Meson Build System to be compiled. Once you have it installed, do:

$ meson build/
$ meson compile -C build/

Then, inside the build directory you will find the binaries.

Features

• 65535 8-bit cells.
• Bytecode parsing and optimization.

Just-In-Time code compilation

The interpreter also includes a JIT compiler for Brainfuck, that can be used with the --jit flag, although it is only supported on few platforms:

• Linux (x86_64)

Usage

$ brainfuck_interpreter <filename.bf> [--jit]

Benchmarks

The following tests were conducted on an Intel Core i7-7700k 4.20GHz processor on Ubuntu 20.04 LTS; the program was compiled using GCC 9.3.0 with the following flags: -O3 -march=native.

Program	Interpreter	JIT compiled code
mandelbrot.bf	3.62s	1.42s
hanoi.bf	0.32s	0.17s
project_euler_1.bf	12.24s	4.78s

Optimizations

Currently the interpreter has the optimization features shown below.

Combining instructions

>, <, +, - instructions are not executed one by one, but the interpreter sums/subtracts the times they are repeated either to ptr or *ptr. For example, >>> becomes ptr+=3.

Position jump

Unlike some other interpreter, this one automatically jumps at the end and at the start of cycles without crossing them entirely.

Loops to zero

When [-] or [+] (loops that continues till the current cell becomes zero) occur, the interpreter directly sets *ptr to 0.

Special thanks

Thanks to GaggiX for helping.