Confusing difference between float and integer in min and max

[lukaslihotzki]

I tried this code:

let a = u32x4::from_array([0, 1, 0, 1]);
let b = u32x4::from_array([1, 0, 1, 0]);
print!("{:x?} ", a.min(b));

let a = f32x4::from_array([0., 1., 0., 1.]);
let b = f32x4::from_array([1., 0., 1., 0.]);
print!("{:x?}\n", a.min(b));

I expected to see this happen: [0, 0, 0, 0] [0.0, 0.0, 0.0, 0.0].
[0, 1, 0, 1] [0.0, 1.0, 0.0, 1.0] would be a little surprising, because that isn't commonly available as native SIMD instruction.

Instead, this happened: [0, 1, 0, 1] [0.0, 0.0, 0.0, 0.0]

This is inconsistent. I expected either min or lanes_min (like in lanes_eq) to get the minimum for each lane.

Also, when you search min( in https://rust-lang.github.io/portable-simd/core_simd/simd/struct.Simd.html#method.min-1, where it says "Returns the minimum of each lane.", you have to scroll up quite a bit to see it is for floats only and the documentation of min and max for integers is very generic, doesn't explicitly mention that this isn't per lane.

[programmerjake]

we should probably add integer min/max operations.

[calebzulawski]

I added them in #206 but that never made it to master 😔

[programmerjake]

ran into this same issue with clamp in #253