llvm-block

llvm-block catches identical basic blocks between two modules.
Since llvm-block draws on debug info, input modules should be generated with -g option.

Prerequisites

cmake >= 3.25 
llvm >= 14

Build

git clone https://github.com/kc-ml2/llvm-block.git
cd llvm-block
export LLVM_ROOT=<path to llvm source root>
cmake --preset=default && cmake --build build 
./llvm-block/llvm-block <before> <after>

*If would like to build in a MacOS environment, run with the macos preset instead (cmake --preset=macos && cmake --build build)

Quick Commands

clang -O0 -g -Xclang -disable-O0-optnone -emit-llvm -S *.c
llvm-link *.ll -S -o beforeg.ll
opt beforeg.ll -S <transform pass> -o afterg.ll

<path to llvm-block>/llvm-block beforeg.ll afterg.ll 2> output

opt —strip-debug -S beforeg.ll -o before.ll
opt —strip-debug -S afterg.ll -o after.ll

mkdir before after
opt -dot-cfg before.ll
mv .*.dot before
opt -dot-cfg after.ll
mv .*.dot after

TLDR script

If you are too bothered to run the commands above, simply run run-llvm-block.sh with the following instructions.

1. First add a *.c file to any directory, say you have foo/a.c.

2. Then simply run bash run-llvm-block.sh foo (checkout the code for more options if you are on MacOS).