Benchmarking libc::random vs. XorShiftRng

bench.rs

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

extern crate test;
extern crate rand;

use rand::Rng;

extern "C" {
    pub fn random() -> i64;
    pub fn srandom(arg1: u32);
}

#[cfg(test)]
mod tests {
	use super::*;
	use test::Bencher;

	#[bench]
	fn libc_random(b: &mut Bencher) {
		b.iter(|| unsafe{random()});
	}

	#[bench]
	fn xorshift_random(b: &mut Bencher) {
		let mut rng = rand::XorShiftRng::new_unseeded();
		b.iter(|| rng.next_u64());
	}
}