You just create f32x4 types, the wide crate does this. Then it autovectorizes just fine. But it still isn't the best idea if you are comparing values. We had a defect due to this recently.

I suspect I am misunderstanding. If you create an f32x4 type, aren't you manually vectorizing? Auto-vectoring is magic SIMD use the compiler does in some cases. (But usually doesn't...)