Function safe_arch::unpack_low_m128d

#[must_use]pub fn unpack_low_m128d(a: m128d, b: m128d) -> m128d

This is supported with target feature sse2 only.

Unpack and interleave low lanes of a and b.

let a = m128d::from_array([92.0, 87.5]);
let b = m128d::from_array([100.0, -6.0]);
let c = unpack_low_m128d(a, b).to_array();
assert_eq!(c, [92.0, 100.0]);