use std::arch::aarch64::*;
#[target_feature(enable = "neon")]
#[allow(clippy::missing_safety_doc)]
pub unsafe fn neon_cosine_similarity_bytes(v1: &[u8], v2: &[u8]) -> f32 {
debug_assert!(v1.len() == v2.len());
let mut ptr1: *const u8 = v1.as_ptr();
let mut ptr2: *const u8 = v2.as_ptr();
unsafe {
let mut mul1 = vdupq_n_u32(0);
let mut mul2 = vdupq_n_u32(0);
let mut norm11 = vdupq_n_u32(0);
let mut norm12 = vdupq_n_u32(0);
let mut norm21 = vdupq_n_u32(0);
let mut norm22 = vdupq_n_u32(0);
let len = v1.len();
for _ in 0..len / 16 {
let p1 = vld1q_u8(ptr1);
let p2 = vld1q_u8(ptr2);
ptr1 = ptr1.add(16);
ptr2 = ptr2.add(16);
let p1_low = vget_low_u8(p1);
let p1_high = vget_high_u8(p1);
let p2_low = vget_low_u8(p2);
let p2_high = vget_high_u8(p2);
let mul_low = vmull_u8(p1_low, p2_low);
let mul_high = vmull_u8(p1_high, p2_high);
mul1 = vpadalq_u16(mul1, mul_low);
mul2 = vpadalq_u16(mul2, mul_high);
let mul_low = vmull_u8(p1_low, p1_low);
let mul_high = vmull_u8(p1_high, p1_high);
norm11 = vpadalq_u16(norm11, mul_low);
norm12 = vpadalq_u16(norm12, mul_high);
let mul_low = vmull_u8(p2_low, p2_low);
let mul_high = vmull_u8(p2_high, p2_high);
norm21 = vpadalq_u16(norm21, mul_low);
norm22 = vpadalq_u16(norm22, mul_high);
}
let mut dot_product = vaddvq_u32(vaddq_u32(mul1, mul2)) as f32;
let mut norm1 = vaddvq_u32(vaddq_u32(norm11, norm12)) as f32;
let mut norm2 = vaddvq_u32(vaddq_u32(norm21, norm22)) as f32;
let remainder = len % 16;
if remainder != 0 {
let mut remainder_dot_product = 0;
let mut remainder_norm1 = 0;
let mut remainder_norm2 = 0;
for _ in 0..remainder {
let v1 = *ptr1;
let v2 = *ptr2;
ptr1 = ptr1.add(1);
ptr2 = ptr2.add(1);
remainder_dot_product += i32::from(v1) * i32::from(v2);
remainder_norm1 += i32::from(v1) * i32::from(v1);
remainder_norm2 += i32::from(v2) * i32::from(v2);
}
dot_product += remainder_dot_product as f32;
norm1 += remainder_norm1 as f32;
norm2 += remainder_norm2 as f32;
}
let denominator = norm1 * norm2;
if denominator == 0.0 {
return 0.0;
}
dot_product / denominator.sqrt()
}
}
#[cfg(test)]
mod tests {
use std::arch::is_aarch64_feature_detected;
use super::*;
use crate::segment::spaces::metric_uint::simple_cosine::cosine_similarity_bytes;
#[test]
fn test_spaces_neon() {
if is_aarch64_feature_detected!("neon") {
let v1: Vec<u8> = vec![
255, 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 255, 255,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 255, 255, 0, 1, 2, 3,
4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 255, 255, 0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 255, 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17,
];
let v2: Vec<u8> = vec![
255, 255, 0, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241,
240, 239, 238, 255, 255, 255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245,
244, 243, 242, 241, 240, 239, 238, 255, 255, 255, 254, 253, 252, 251, 250, 249,
248, 247, 246, 245, 244, 243, 242, 241, 240, 239, 238, 255, 255, 255, 254, 253,
252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 240, 239, 238, 255,
255, 255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241,
240, 239, 238,
];
let dot_simd = unsafe { neon_cosine_similarity_bytes(&v1, &v2) };
let dot = cosine_similarity_bytes(&v1, &v2);
assert_eq!(dot_simd, dot);
} else {
println!("neon test skipped");
}
}
#[test]
fn test_zero_neon() {
if is_aarch64_feature_detected!("neon") {
let v1: Vec<u8> = vec![0, 0, 0, 0, 0, 0, 0, 0];
let v2: Vec<u8> = vec![255, 255, 0, 254, 253, 252, 251, 250];
let dot_simd = unsafe { neon_cosine_similarity_bytes(&v1, &v2) };
assert_eq!(dot_simd, 0.0);
let dot_simd = unsafe { neon_cosine_similarity_bytes(&v2, &v1) };
assert_eq!(dot_simd, 0.0);
let dot_simd = unsafe { neon_cosine_similarity_bytes(&v1, &v1) };
assert_eq!(dot_simd, 0.0);
} else {
println!("neon test skipped");
}
}
}