#![feature(test, asm)]
extern crate test;
use test::Bencher;
use std::alloc::{alloc, dealloc, alloc_zeroed, Layout};

#[bench]
fn bench_alloc_4096(b: &mut Bencher) {
    let layout = Layout::from_size_align(4096, 1).unwrap();
    b.iter(|| unsafe {
        let x = alloc(layout);
        *x = 1;
        asm!("" : : "m"(x) : :"volatile");
        dealloc(x, layout);
    });
}

#[bench]
fn bench_alloc_memset_4096(b: &mut Bencher) {
    let layout = Layout::from_size_align(4096, 1).unwrap();
    b.iter(|| unsafe {
        let x = alloc(layout);
        std::ptr::write_bytes(x, 0, layout.size());
        *x = 1;
        asm!("" : : "m"(x) : :"volatile");
        dealloc(x, layout);
    });
}


#[bench]
fn bench_alloc_zeroed_4096(b: &mut Bencher) {
    let layout = Layout::from_size_align(4096, 1).unwrap();
    b.iter(|| unsafe {
        let x = alloc_zeroed(layout);
        *x = 1;
        asm!("" : : "m"(x) : :"volatile");
        dealloc(x, layout);
    });
}

/*
rustc +nightly -O --test foo.rs && ./foo --bench

running 3 tests
test bench_alloc_4096        ... bench:          47 ns/iter (+/- 11)
test bench_alloc_memset_4096 ... bench:         133 ns/iter (+/- 9)
test bench_alloc_zeroed_4096 ... bench:         137 ns/iter (+/- 23)

test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured; 0 filtered out

*/