Function abs_s 

pub const fn abs_s(a: f32) -> f32

ABS.S — clears the sign bit.

Written as an explicit bit clear rather than f32::abs. The two are equivalent, including for NaN payloads — mutation testing confirmed swapping them changes nothing — so this is a readability choice, not a correctness one: the hardware operation is a bit clear, and saying so makes the NaN-payload behavior obvious instead of something to look up.