https://doc.rust-lang.org/stable/core/arch/x86/fn._mm256_extracti64x2_epi64.html
_mm256_extracti64x2_epi64 in core::arch::x86 - Rust
Extracts 128 bits (composed of 2 packed 64-bit integers) from a, selected with IMM8, and stores the result in dst.
corearchrust