Awesome

Brainf*ck

Build

It should be fairly easy for anyone who has make installed.

The interpreter

run ./bfi <bf source> or simply omit the argument and provide your source using the stdin.

./bfi <<EOF
++++++++++
[>+++++++>
++++++++++
>+++>+<<<<
-]>++.>+.+
++++++..++
+.>++.<<++
++++++++++
+++.>.+++.
------.---
-----.>+.>.
EOF

should give you back the classic "Hello World!"

A section on quine

A quine is included, and its construction is also included.

Specifically, You can take a look at the Makefile, quine-data.c and quine-code.part. These three files should give you some clue about how the quine is constructed.

To generate it by yourself, you can first remove quine.bf by rm quine.bf and then run make quine.bf, or simply make clean quine.bf.

To check that it is indeed a quine, diff should be helpful. diff quine.bf <(./bfi quine.bf) should show you nothing.

JIT

This BF interpreter also has JIT support on x86-64. The JIT will kick in every time a real backward jump happens, i.e., ] encountered when the current cell is non-zero. This avoids compilation when the loop is never or only executed once. When the loop is finished, the execution will be handled back to the interpreter and the interpreter will start executing bytecode until the next backward jump happens. The assembler is currently hacky but it works. The blocks are organized in the code page and are linked by jumps.

As measured, the performance boost of the JIT compiler on a Macbook Pro 2018 is 10x on mandelbrot-titanic.b.