Function safe_arch::truncate_to_i64_m128d_s

pub fn truncate_to_i64_m128d_s(a: m128d) -> i64

Truncate the lower lane into an i64.

let a = m128d::from_array([1.7, 2.6]);
assert_eq!(truncate_to_i64_m128d_s(a), 1_i64);