hammcmp_256bit_avx2.rs

#[cfg(all(target_arch = "x86_64", target_feature = "avx2"))]
unsafe fn hammcmp_256bit_avx2(mut a: &[u8], mut b: &[u8]) -> u32 {
    use std::arch::x86_64::{*};
    let mut dist = 0;
    while a.len() >= 32 {
        let av = _mm256_loadu_si256(a.as_ptr() as *const _);
        let bv = _mm256_loadu_si256(b.as_ptr() as *const _);
        let axorb = _mm256_xor_si256(av, bv);
        dist += _popcnt64(_mm256_extract_epi64(axorb, 0));
        dist += _popcnt64(_mm256_extract_epi64(axorb, 1));
        dist += _popcnt64(_mm256_extract_epi64(axorb, 2));
        dist += _popcnt64(_mm256_extract_epi64(axorb, 3));
        a = &a[32..];
        b = &b[32..];
    }
    debug_assert_eq!(a.len(), 0);
    dist as u32
}