Safety Net: A Memory-Safe Netlist Data Structure via Reference Counting

Description

A Rust library for compiling and mutating netlists in a memory-safe way

You can read the docs for the netlist library here, but you may also want to check out the cool side-projects using safety-net:

• nl-compiler - Verilog frontend compilation into safety-net
• safety-pass - Build your own compiler pass pipelines that operate over safety-net netlists + provides a library of logic cells
• eqmap - uses equality saturation to superoptimize netlists

Getting Started

Below is a minimal example to get you started:

use safety_net::{Gate, Netlist};

fn and_gate() -> Gate {
    Gate::new_logical(
        "AND".into(),
        vec!["A".into(), "B".into()],
        "Y".into(),
    )
}

fn main() {
    let netlist = Netlist::new("example".to_string());

    // Add the the two inputs
    let a = netlist.insert_input("a".into());
    let b = netlist.insert_input("b".into());

    // Instantiate an AND gate
    let instance = netlist
        .insert_gate(and_gate(), "inst_0".into(), &[a, b])
        .unwrap();

    // Make this AND gate an output
    instance.expose_with_name("y".into());

    // Print the netlist
    println!("{netlist}");
}

This code is included in the crate and you can run it with cargo run --example simple. Of course, you should generate the documentation with cargo doc and give it a review.

Exporting to MultiDiGraph with the petgraph Crate

The API provides the basic iterators needed to implement graph algorithms like static timing analysis:

• iter() (The circuit nodes)
• connections() (The edges)
• node_dfs() (Depth-first search)

However, you may want to use another library that leverages a denser representation and already has all the classic algorithms implemented. This crate provides integration with petgraph. Here is a ripple-carry adder example which converts the netlist to a petgraph which is then converted to a dot graph:

cargo run --features graph --example pretty | dot -Tsvg > adder.svg

Then, open it up and take a look: