🎷 Debug Like a Human: Scaling LLM-based Fault Localization to Processor Design via Block-Level Instruction-Oriented Slicing

Note

We recently refactored BluesFL into sv-analyzer — a cleaner codebase with the core Blues slicing engine, plus TUI, CLI, MCP server, and VS Code extension support for IDE/agent integration. Note that sv-analyzer is still in active development and may not yet be stable.

This artifact includes:

• the code for our BluesFL tool in: src/bin/sv_analysis
• bug inject tool in : src/bin/mutator
• metric calculator: src/cal_metric
• our dataset: dataset
• results of BluesFL and other baselines: results
• run experiment scripts: exps and scripts

Note

You may find the name "BiosFL" in this artifact, which was the initial name for our "BluesFL". Since BIOS sounds very similar to the Basic I/O System (BIOS), we decided to update it in our paper.

1. Installation

Environment

We only test BluesFL in Ubuntu 22.04.

export SV_ANALYSIS_HOME=$(pwd)

cp .env.example .env
# fill in your api key in .env

Python

Please make sure that you have Python in version 3.12 or newer installed. We have tested all scripts with Python 3.12.2.

Rust

Please make sure you have a recent version of Rust installed. Update your version to the latest (most commonly through rustup update). We build BluesFL with rustc 1.89.0-nightly (5d707b07e 2025-06-02).

Verilator

We are using a custom Verilator that dumps AST information after removing all parameter-controlled code. But the modification is very little, so you can download the source of Verilator and apply our patch to version 5.037, then compile and install it.

git apply doc/patches/0001-verilator-dump-rm-params.patch

# Prerequisites:
#sudo apt-get install git help2man perl python3 make autoconf g++ flex bison ccache
#sudo apt-get install libgoogle-perftools-dev numactl perl-doc
#sudo apt-get install libfl2  # Ubuntu only (ignore if it gives an error)
#sudo apt-get install libfl-dev  # Ubuntu only (ignore if it gives an error)
#sudo apt-get install zlibc zlib1g zlib1g-dev  # Ubuntu only (ignore if it gives an error)

git clone https://github.com/verilator/verilator
cd verilator
git checkout v5.037
git apply $SV_ANALYSIS_HOME/doc/patches/0001-verilator-dump-rm-params.patch

autoconf         # Create ./configure script
./configure      # Configure and create Makefile
make -j `nproc`  # Build Verilator itself (if error, try just 'make')
sudo make install

$ verilator --version                                              
Verilator 5.037 devel rev UNKNOWN.REV (mod)

2. Setup Dataset

See the full guide in setup_dataset.md.

3. Artifact Setup

Building BluesFL is very simple, just cargo build, it will build the final bin at target/debug/sv_analysis.

cd $SV_ANALYSIS_HOME
git submodule update --init --recursive
cargo build

4. Artifact Instructions

Run BluesFL & Baselines

See the full guide in run_bluesfl.md and baselines.md.

After running all, results are all saved to results folder in respective folders.

Calculate Metric

Run script exps/metric_all.sh, and all metric results will be saved in exps/metrics_out.

Generate Tables

We provide scripts to plot Figure 4, 5 and 7 in our experiment section from the data we previously collected.

• Figure 4:

# After running BluesFL, a file `blocks.json` will be generated.
python scripts/plot_blocks.py 

• Figure 5:

python scripts/plot_trace_size_dis.py --root /home/lzz/dac26/hdl_fl_data/dataset \ 
    --prefix biosfl_res_gpt-4o_vt2_vk2 biosfl_res_b268051_ablation_rm_exe_path_gpt-4o_vt2_vk2 biosfl_res_fd36321_ablation_rm_sig_values_gpt-4o_vt2_vk2 \
    --name-map BluesFL "w/o instruction path" "w/o signal values"

• Figure 7:

python scripts/cal_hit_or_not.py