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Diffstat (limited to 'vendor/simd-adler32/src/imp/neon.rs')
| -rw-r--r-- | vendor/simd-adler32/src/imp/neon.rs | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/vendor/simd-adler32/src/imp/neon.rs b/vendor/simd-adler32/src/imp/neon.rs new file mode 100644 index 0000000..8398b6d --- /dev/null +++ b/vendor/simd-adler32/src/imp/neon.rs @@ -0,0 +1,241 @@ +use super::Adler32Imp; + +/// Resolves update implementation if CPU supports avx512f and avx512bw instructions. +pub fn get_imp() -> Option<Adler32Imp> { + get_imp_inner() +} + +#[inline] +#[cfg(all(feature = "std", feature = "nightly", target_arch = "arm"))] +fn get_imp_inner() -> Option<Adler32Imp> { + if std::is_arm_feature_detected("neon") { + Some(imp::update) + } else { + None + } +} + +#[inline] +#[cfg(all(feature = "std", feature = "nightly", target_arch = "aarch64"))] +fn get_imp_inner() -> Option<Adler32Imp> { + if std::is_aarch64_feature_detected("neon") { + Some(imp::update) + } else { + None + } +} + +#[inline] +#[cfg(all( + feature = "nightly", + target_feature = "neon", + not(all(feature = "std", any(target_arch = "arm", target_arch = "aarch64"))) +))] +fn get_imp_inner() -> Option<Adler32Imp> { + Some(imp::update) +} + +#[inline] +#[cfg(all( + not(target_feature = "neon"), + not(all( + feature = "std", + feature = "nightly", + any(target_arch = "arm", target_arch = "aarch64") + )) +))] +fn get_imp_inner() -> Option<Adler32Imp> { + None +} + +#[cfg(all( + feature = "nightly", + any(target_arch = "arm", target_arch = "aarch64"), + any(feature = "std", target_feature = "neon") +))] +mod imp { + const MOD: u32 = 65521; + const NMAX: usize = 5552; + const BLOCK_SIZE: usize = 64; + const CHUNK_SIZE: usize = NMAX / BLOCK_SIZE * BLOCK_SIZE; + + #[cfg(target_arch = "aarch64")] + use core::arch::aarch64::*; + #[cfg(target_arch = "arm")] + use core::arch::arm::*; + + pub fn update(a: u16, b: u16, data: &[u8]) -> (u16, u16) { + unsafe { update_imp(a, b, data) } + } + + #[inline] + #[target_feature(enable = "neon")] + unsafe fn update_imp(a: u16, b: u16, data: &[u8]) -> (u16, u16) { + let mut a = a as u32; + let mut b = b as u32; + + let chunks = data.chunks_exact(CHUNK_SIZE); + let remainder = chunks.remainder(); + for chunk in chunks { + update_chunk_block(&mut a, &mut b, chunk); + } + + update_block(&mut a, &mut b, remainder); + + (a as u16, b as u16) + } + + #[inline] + unsafe fn update_chunk_block(a: &mut u32, b: &mut u32, chunk: &[u8]) { + debug_assert_eq!( + chunk.len(), + CHUNK_SIZE, + "Unexpected chunk size (expected {}, got {})", + CHUNK_SIZE, + chunk.len() + ); + + reduce_add_blocks(a, b, chunk); + + *a %= MOD; + *b %= MOD; + } + + #[inline] + unsafe fn update_block(a: &mut u32, b: &mut u32, chunk: &[u8]) { + debug_assert!( + chunk.len() <= CHUNK_SIZE, + "Unexpected chunk size (expected <= {}, got {})", + CHUNK_SIZE, + chunk.len() + ); + + for byte in reduce_add_blocks(a, b, chunk) { + *a += *byte as u32; + *b += *a; + } + + *a %= MOD; + *b %= MOD; + } + + #[inline(always)] + unsafe fn reduce_add_blocks<'a>(a: &mut u32, b: &mut u32, chunk: &'a [u8]) -> &'a [u8] { + if chunk.len() < BLOCK_SIZE { + return chunk; + } + + let blocks = chunk.chunks_exact(BLOCK_SIZE); + let blocks_remainder = blocks.remainder(); + + let one_v = _mm512_set1_epi16(1); + let zero_v = _mm512_setzero_si512(); + let weights = get_weights(); + + let p_v = (*a * blocks.len() as u32) as _; + let mut p_v = _mm512_set_epi32(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, p_v); + let mut a_v = _mm512_setzero_si512(); + let mut b_v = _mm512_set_epi32(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, *b as _); + + for block in blocks { + let block_ptr = block.as_ptr() as *const _; + let block = _mm512_loadu_si512(block_ptr); + + p_v = _mm512_add_epi32(p_v, a_v); + + a_v = _mm512_add_epi32(a_v, _mm512_sad_epu8(block, zero_v)); + let mad = _mm512_maddubs_epi16(block, weights); + b_v = _mm512_add_epi32(b_v, _mm512_madd_epi16(mad, one_v)); + } + + b_v = _mm512_add_epi32(b_v, _mm512_slli_epi32(p_v, 6)); + + *a += reduce_add(a_v); + *b = reduce_add(b_v); + + blocks_remainder + } + + #[inline(always)] + unsafe fn reduce_add(v: __m512i) -> u32 { + let v: [__m256i; 2] = core::mem::transmute(v); + + reduce_add_256(v[0]) + reduce_add_256(v[1]) + } + + #[inline(always)] + unsafe fn reduce_add_256(v: __m256i) -> u32 { + let v: [__m128i; 2] = core::mem::transmute(v); + let sum = _mm_add_epi32(v[0], v[1]); + let hi = _mm_unpackhi_epi64(sum, sum); + + let sum = _mm_add_epi32(hi, sum); + let hi = _mm_shuffle_epi32(sum, crate::imp::_MM_SHUFFLE(2, 3, 0, 1)); + + let sum = _mm_add_epi32(sum, hi); + let sum = _mm_cvtsi128_si32(sum) as _; + + sum + } + + #[inline(always)] + unsafe fn get_weights() -> __m512i { + _mm512_set_epi8( + 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, + 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, + 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, + ) + } +} + +#[cfg(test)] +mod tests { + use rand::Rng; + + #[test] + fn zeroes() { + assert_sum_eq(&[]); + assert_sum_eq(&[0]); + assert_sum_eq(&[0, 0]); + assert_sum_eq(&[0; 100]); + assert_sum_eq(&[0; 1024]); + assert_sum_eq(&[0; 1024 * 1024]); + } + + #[test] + fn ones() { + assert_sum_eq(&[]); + assert_sum_eq(&[1]); + assert_sum_eq(&[1, 1]); + assert_sum_eq(&[1; 100]); + assert_sum_eq(&[1; 1024]); + assert_sum_eq(&[1; 1024 * 1024]); + } + + #[test] + fn random() { + let mut random = [0; 1024 * 1024]; + rand::thread_rng().fill(&mut random[..]); + + assert_sum_eq(&random[..1]); + assert_sum_eq(&random[..100]); + assert_sum_eq(&random[..1024]); + assert_sum_eq(&random[..1024 * 1024]); + } + + /// Example calculation from https://en.wikipedia.org/wiki/Adler-32. + #[test] + fn wiki() { + assert_sum_eq(b"Wikipedia"); + } + + fn assert_sum_eq(data: &[u8]) { + if let Some(update) = super::get_imp() { + let (a, b) = update(1, 0, data); + let left = u32::from(b) << 16 | u32::from(a); + let right = adler::adler32_slice(data); + + assert_eq!(left, right, "len({})", data.len()); + } + } +} |