llvm-brainfuck

A LLVM pass that lowers LLVM IR to Brainfuck.

Work in progress -- not all instructions and types are supported yet.

Quick Start

mkdir build && cd build
cmake .. && make
clang -O1 -S -fpass-plugin=./lib/libLLVMBrainfuck.so -o /dev/null ../tests/c/helloworld.c > helloworld.bf
./interpreter/BFInterp helloworld.bf
 
# For opt, use `-load-pass-plugin` 
# opt -load-pass-plugin ./lib/libLLVMBrainfuck.so -disable-output xxx.ll

Progress

• Basic support for arithmetic, memory and function calls.
• Currently, all types are treated as i8 and conversion are simply ignored.
• ⚡ Fun Fact: Now it can compile a Brainfuck interpreter to Brainfuck. (See: tests/c/bf-interp.c)

Supported Instructions

Terminator Instructions

• ret
• br
• switch
• indirectbr
• invoke
• callbr
• resume
• catchswitch
• catchret
• cleanupret
• unreachable

Unary Operations

• fneg

Binary Operations

• add
• fadd
• sub
• fsub
• mul
• fmul
• udiv
• sdiv
• fdiv
• urem
• srem
• frem

Bitwise Binary Operations

• shl
• lshr
• ashr
• and
• or
• xor

Vector Operations

• extractelement
• insertelement
• shufflevector

Aggregate Operations

• extractvalue
• insertvalue

Memory Access and Addressing Operations

• alloca
• load
• store
• fence
• cmpxchg
• atomicrmw
• getelementptr

Conversion Operations

• trunc ... to
• zext ... to
• sext ... to
• fptrunc ... to
• fpext ... to
• fptoui ... to
• fptosi ... to
• uitofp ... to
• sitofp ... to
• ptrtoint ... to
• inttoptr ... to
• bitcast ... to
• addrspacecast ... to

Other Operations

• icmp
• fcmp
• phi (demote to memory)
• select
• freeze
• call
• va_arg
• landingpad
• catchpad
• cleanuppad

Supported Types

• i8
• ...

License

This project is licensed under the MIT License.
See LICENSE for details.