/// Slightly modify the example on crate `simd` to make it work on stable channel 
/// Reference link : https://github.com/rust-lang-nursery/simd

extern crate ssimd;
use ssimd::{f32x4, f32x8};

#[inline(never)]
pub fn axpy(z: &mut [f32], a: f32, x: &[f32], y: &[f32]) {
    assert_eq!(x.len(), y.len());
    assert_eq!(x.len(), z.len());

    let len = std::cmp::min(std::cmp::min(x.len(), y.len()), z.len());

    let mut i = 0;
    while i < len & !3 {
        let x = f32x4::load(x, i);
        let y = f32x4::load(y, i);
        (f32x4::splat(a) * x + y).store(z, i);
        i += 4
    }
}

#[inline(never)]
pub fn axpy8(z: &mut [f32], a: f32, x: &[f32], y: &[f32]) {
    assert_eq!(x.len(), y.len());
    assert_eq!(x.len(), z.len());

    let len = std::cmp::min(std::cmp::min(x.len(), y.len()), z.len());

    let mut i = 0;
    while i < len & !7 {
        let x = f32x8::load(x, i);
        let y = f32x8::load(y, i);
        (f32x8::splat(a) * x + y).store(z, i);
        i += 8
    }
}

fn main() {
    let mut z = vec![0.; 4];
    axpy(&mut z, 2., &[1.0, 3.0, 5.0, 7.0], &[2.0, 4.0, 6.0, 8.0]);
    println!("{:?}", z);
    let mut z = vec![0.; 8];
    axpy(&mut z, 3., &[1.0, 3.0, 6.0, 7.0, 10.0, 6.0, 3.0, 2.0],
                       &[2.0, 4.0, 6.0, 8.0, 2.0, 4.0, 6.0, 8.0]);
    println!("{:?}", z);

    let mut z = vec![0.; 4];
    axpy8(&mut z, 2., &[1.0, 3.0, 5.0, 7.0], &[2.0, 4.0, 6.0, 8.0]);
    println!("{:?}", z);
    let mut z = vec![0.; 8];
    axpy8(&mut z, 3., &[1.0, 3.0, 6.0, 7.0, 10.0, 6.0, 3.0, 2.0],
                       &[2.0, 4.0, 6.0, 8.0, 2.0, 4.0, 6.0, 8.0]);
    println!("{:?}", z);
}