rusty-numbers/benches/stock_functions.rs

use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
use rusty_numbers::num::Unsigned;
use rusty_numbers::{factorial, fibonacci, it_factorial, mem_fibonacci, rec_fibonacci};

fn bench_factorial(c: &mut Criterion) {
    let mut group = c.benchmark_group("Factorials");

    for i in [0usize, 5, 10, 15, 20, 25, 30, 34].iter() {
        group.bench_with_input(BenchmarkId::new("Recursive naive", i), i, |b, i| {
            b.iter(|| factorial(black_box(*i)))
        });
        group.bench_with_input(BenchmarkId::new("Iterative", i), i, |b, i| {
            b.iter(|| it_factorial(black_box(*i)))
        });
    }
    group.finish();
}

fn bench_fibonacci(c: &mut Criterion) {
    let mut group = c.benchmark_group("Fibonacci");

    for i in [0usize, 10, 20, 30, 40, 50, 70, 93, 140, 186].iter() {
        group.bench_with_input(BenchmarkId::new("Recursive memoized", i), i, |b, i| {
            b.iter(|| mem_fibonacci(black_box(*i)))
        });
        group.bench_with_input(BenchmarkId::new("Iterative", i), i, |b, i| {
            b.iter(|| fibonacci(black_box(*i)))
        });
    }

    group.finish();

    let mut group = c.benchmark_group("Recursive Fibonacci");
    for i in [0usize, 10, 20, 25, 26, 27, 28, 29, 30].iter() {
        group.bench_with_input(BenchmarkId::new("Naive Recursive", i), i, |b, i| {
            b.iter(|| rec_fibonacci(black_box(*i)))
        });
    }
    group.finish();
}

fn bench_gcd(c: &mut Criterion) {
    let mut group = c.benchmark_group("GCD");

    #[derive(Debug)]
    struct Gcd {
        left: u128,
        right: u128,
        left_fib: u128,
        right_fib: u128,
    }

    impl Gcd {
        fn new(left: u128, right: u128) -> Self {
            Gcd {
                left,
                right,
                left_fib: fibonacci(left as usize).unwrap(),
                right_fib: fibonacci(right as usize).unwrap(),
            }
        }
    }

    let max = Gcd::new(185, 186);
    let med = Gcd::new(92, 93);
    let small = Gcd::new(14, 15);

    for input in [small, med, max].iter() {
        group.bench_with_input(
            BenchmarkId::new("Binary", input.left),
            input,
            |bench, input| {
                let a = input.left_fib;
                let b = input.right_fib;
                bench.iter(|| u128::gcd(black_box(a), black_box(b)))
            },
        );
        group.bench_with_input(
            BenchmarkId::new("Stein", input.left),
            input,
            |bench, input| {
                let a = input.left_fib;
                let b = input.right_fib;
                bench.iter(|| u128::stein_gcd(black_box(a), black_box(b)))
            },
        );
        group.bench_with_input(
            BenchmarkId::new("Euclid", input.left),
            input,
            |bench, input| {
                let a = input.left_fib;
                let b = input.right_fib;
                bench.iter(|| u128::e_gcd(black_box(a), black_box(b)))
            },
        );
    }
    group.finish();
}

criterion_group!(benches, bench_factorial, bench_fibonacci, bench_gcd);
criterion_main!(benches);