// Copyright 2015-2017 Parity Technologies
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! benchmarking for bigint
//! should be started with:
//! ```bash
//! rustup run nightly cargo bench
//! ```

#![feature(test)]
#![feature(asm)]

extern crate test;
extern crate bigint;

use test::{Bencher, black_box};
use bigint::{U256, U512, U128};

#[bench]
fn u256_add(b: &mut Bencher) {
	b.iter(|| {
		let n = black_box(10000);
		let zero = black_box(U256::zero());
		(0..n).fold(zero, |old, new| { old.overflowing_add(U256::from(black_box(new))).0 })
	});
}

#[bench]
fn u256_sub(b: &mut Bencher) {
	b.iter(|| {
		let n = black_box(10000);
		let max = black_box(U256::max_value());
		(0..n).fold(max, |old, new| { old.overflowing_sub(U256::from(black_box(new))).0 })
	});
}

#[bench]
fn u512_sub(b: &mut Bencher) {
	b.iter(|| {
		let n = black_box(10000);
		let max = black_box(U512::max_value());
		(0..n).fold(
			max,
			|old, new| {
				let new = black_box(new);
				let p = new % 2;
				old.overflowing_sub(U512([p, p, p, p, p, p, p, new])).0
			}
		)
	});
}

#[bench]
fn u512_add(b: &mut Bencher) {
	b.iter(|| {
		let n = black_box(10000);
		let zero = black_box(U512::zero());
		(0..n).fold(zero,
			|old, new| {
				let new = black_box(new);
				old.overflowing_add(U512([new, new, new, new, new, new, new, new])).0
			})
	});
}

#[bench]
fn u256_mul(b: &mut Bencher) {
	b.iter(|| {
		let n = black_box(10000);
		let one = black_box(U256::one());
		(0..n).fold(one, |old, new| { old.overflowing_mul(U256::from(black_box(new))).0 })
	});
}


#[bench]
fn u256_full_mul(b: &mut Bencher) {
	b.iter(|| {
		let n = black_box(10000);
		let one = black_box(U256::one());
		(0..n).fold(one,
			|old, new| {
				let new = black_box(new);
				let U512(ref u512words) = old.full_mul(U256([new, new, new, new]));
				U256([u512words[0], u512words[2], u512words[2], u512words[3]])
			})
	});
}


#[bench]
fn u128_mul(b: &mut Bencher) {
	b.iter(|| {
		let n = black_box(10000);
		(0..n).fold(U128([12345u64, 0u64]), |old, new| { old.overflowing_mul(U128::from(new)).0 })
	});
}