diff options
Diffstat (limited to 'vendor/crc32fast/src/specialized/aarch64.rs')
-rw-r--r-- | vendor/crc32fast/src/specialized/aarch64.rs | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/vendor/crc32fast/src/specialized/aarch64.rs b/vendor/crc32fast/src/specialized/aarch64.rs deleted file mode 100644 index 49de6b0..0000000 --- a/vendor/crc32fast/src/specialized/aarch64.rs +++ /dev/null @@ -1,88 +0,0 @@ -use std::arch::aarch64 as arch; - -#[derive(Clone)] -pub struct State { - state: u32, -} - -impl State { - pub fn new(state: u32) -> Option<Self> { - if std::arch::is_aarch64_feature_detected!("crc") { - // SAFETY: The conditions above ensure that all - // required instructions are supported by the CPU. - Some(Self { state }) - } else { - None - } - } - - pub fn update(&mut self, buf: &[u8]) { - // SAFETY: The `State::new` constructor ensures that all - // required instructions are supported by the CPU. - self.state = unsafe { calculate(self.state, buf) } - } - - pub fn finalize(self) -> u32 { - self.state - } - - pub fn reset(&mut self) { - self.state = 0; - } - - pub fn combine(&mut self, other: u32, amount: u64) { - self.state = ::combine::combine(self.state, other, amount); - } -} - -// target_feature is necessary to allow rustc to inline the crc32* wrappers -#[target_feature(enable = "crc")] -pub unsafe fn calculate(crc: u32, data: &[u8]) -> u32 { - let mut c32 = !crc; - let (pre_quad, quads, post_quad) = data.align_to::<u64>(); - - c32 = pre_quad.iter().fold(c32, |acc, &b| arch::__crc32b(acc, b)); - - // unrolling increases performance by a lot - let mut quad_iter = quads.chunks_exact(8); - for chunk in &mut quad_iter { - c32 = arch::__crc32d(c32, chunk[0]); - c32 = arch::__crc32d(c32, chunk[1]); - c32 = arch::__crc32d(c32, chunk[2]); - c32 = arch::__crc32d(c32, chunk[3]); - c32 = arch::__crc32d(c32, chunk[4]); - c32 = arch::__crc32d(c32, chunk[5]); - c32 = arch::__crc32d(c32, chunk[6]); - c32 = arch::__crc32d(c32, chunk[7]); - } - c32 = quad_iter - .remainder() - .iter() - .fold(c32, |acc, &q| arch::__crc32d(acc, q)); - - c32 = post_quad.iter().fold(c32, |acc, &b| arch::__crc32b(acc, b)); - - !c32 -} - -#[cfg(test)] -mod test { - quickcheck! { - fn check_against_baseline(init: u32, chunks: Vec<(Vec<u8>, usize)>) -> bool { - let mut baseline = super::super::super::baseline::State::new(init); - let mut aarch64 = super::State::new(init).expect("not supported"); - for (chunk, mut offset) in chunks { - // simulate random alignments by offsetting the slice by up to 15 bytes - offset &= 0xF; - if chunk.len() <= offset { - baseline.update(&chunk); - aarch64.update(&chunk); - } else { - baseline.update(&chunk[offset..]); - aarch64.update(&chunk[offset..]); - } - } - aarch64.finalize() == baseline.finalize() - } - } -} |