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path: root/vendor/httparse/src/simd/avx2.rs
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-rw-r--r--vendor/httparse/src/simd/avx2.rs206
1 files changed, 0 insertions, 206 deletions
diff --git a/vendor/httparse/src/simd/avx2.rs b/vendor/httparse/src/simd/avx2.rs
deleted file mode 100644
index 2adf0a28..00000000
--- a/vendor/httparse/src/simd/avx2.rs
+++ /dev/null
@@ -1,206 +0,0 @@
-use crate::iter::Bytes;
-
-#[inline]
-#[target_feature(enable = "avx2")]
-pub unsafe fn match_uri_vectored(bytes: &mut Bytes) {
- while bytes.as_ref().len() >= 32 {
-
- let advance = match_url_char_32_avx(bytes.as_ref());
-
- bytes.advance(advance);
-
- if advance != 32 {
- return;
- }
- }
- // NOTE: use SWAR for <32B, more efficient than falling back to SSE4.2
- super::swar::match_uri_vectored(bytes)
-}
-
-#[inline(always)]
-#[allow(non_snake_case, overflowing_literals)]
-#[allow(unused)]
-unsafe fn match_url_char_32_avx(buf: &[u8]) -> usize {
- // NOTE: This check might be not necessary since this function is only used in
- // `match_uri_vectored` where buffer overflow is taken care of.
- debug_assert!(buf.len() >= 32);
-
- #[cfg(target_arch = "x86")]
- use core::arch::x86::*;
- #[cfg(target_arch = "x86_64")]
- use core::arch::x86_64::*;
-
- // pointer to buffer
- let ptr = buf.as_ptr();
-
- // %x21-%x7e %x80-%xff
- //
- // Character ranges allowed by this function, can also be interpreted as:
- // 33 =< (x != 127) =< 255
- //
- // Create a vector full of DEL (0x7f) characters.
- let DEL: __m256i = _mm256_set1_epi8(0x7f);
- // Create a vector full of exclamation mark (!) (0x21) characters.
- // Used as lower threshold, characters in URLs cannot be smaller than this.
- let LOW: __m256i = _mm256_set1_epi8(0x21);
-
- // Load a chunk of 32 bytes from `ptr` as a vector.
- // We can check 32 bytes in parallel at most with AVX2 since
- // YMM registers can only have 256 bits most.
- let dat = _mm256_lddqu_si256(ptr as *const _);
-
- // unsigned comparison dat >= LOW
- //
- // `_mm256_max_epu8` creates a new vector by comparing vectors `dat` and `LOW`
- // and picks the max. values from each for all indices.
- // So if a byte in `dat` is <= 32, it'll be represented as 33
- // which is the smallest valid character.
- //
- // Then, we compare the new vector with `dat` for equality.
- //
- // `_mm256_cmpeq_epi8` returns a new vector where;
- // * matching bytes are set to 0xFF (all bits set),
- // * nonmatching bytes are set to 0 (no bits set).
- let low = _mm256_cmpeq_epi8(_mm256_max_epu8(dat, LOW), dat);
- // Similar to what we did before, but now invalid characters are set to 0xFF.
- let del = _mm256_cmpeq_epi8(dat, DEL);
-
- // We glue the both comparisons via `_mm256_andnot_si256`.
- //
- // Since the representation of truthiness differ in these comparisons,
- // we are in need of bitwise NOT to convert valid characters of `del`.
- let bit = _mm256_andnot_si256(del, low);
- // This creates a bitmask from the most significant bit of each byte.
- // Simply, we're converting a vector value to scalar value here.
- let res = _mm256_movemask_epi8(bit) as u32;
-
- // Count trailing zeros to find the first encountered invalid character.
- // Bitwise NOT is required once again to flip truthiness.
- // TODO: use .trailing_ones() once MSRV >= 1.46
- (!res).trailing_zeros() as usize
-}
-
-#[target_feature(enable = "avx2")]
-pub unsafe fn match_header_value_vectored(bytes: &mut Bytes) {
- while bytes.as_ref().len() >= 32 {
- let advance = match_header_value_char_32_avx(bytes.as_ref());
- bytes.advance(advance);
-
- if advance != 32 {
- return;
- }
- }
- // NOTE: use SWAR for <32B, more efficient than falling back to SSE4.2
- super::swar::match_header_value_vectored(bytes)
-}
-
-#[inline(always)]
-#[allow(non_snake_case)]
-#[allow(unused)]
-unsafe fn match_header_value_char_32_avx(buf: &[u8]) -> usize {
- debug_assert!(buf.len() >= 32);
-
- #[cfg(target_arch = "x86")]
- use core::arch::x86::*;
- #[cfg(target_arch = "x86_64")]
- use core::arch::x86_64::*;
-
- let ptr = buf.as_ptr();
-
- // %x09 %x20-%x7e %x80-%xff
- // Create a vector full of horizontal tab (\t) (0x09) characters.
- let TAB: __m256i = _mm256_set1_epi8(0x09);
- // Create a vector full of DEL (0x7f) characters.
- let DEL: __m256i = _mm256_set1_epi8(0x7f);
- // Create a vector full of space (0x20) characters.
- let LOW: __m256i = _mm256_set1_epi8(0x20);
-
- // Load a chunk of 32 bytes from `ptr` as a vector.
- let dat = _mm256_lddqu_si256(ptr as *const _);
-
- // unsigned comparison dat >= LOW
- //
- // Same as what we do in `match_url_char_32_avx`.
- // This time the lower threshold is set to space character though.
- let low = _mm256_cmpeq_epi8(_mm256_max_epu8(dat, LOW), dat);
- // Check if `dat` includes `TAB` characters.
- let tab = _mm256_cmpeq_epi8(dat, TAB);
- // Check if `dat` includes `DEL` characters.
- let del = _mm256_cmpeq_epi8(dat, DEL);
-
- // Combine all comparisons together, notice that we're also using OR
- // to connect `low` and `tab` but flip bits of `del`.
- //
- // In the end, this is simply:
- // ~del & (low | tab)
- let bit = _mm256_andnot_si256(del, _mm256_or_si256(low, tab));
- // This creates a bitmask from the most significant bit of each byte.
- // Creates a scalar value from vector value.
- let res = _mm256_movemask_epi8(bit) as u32;
-
- // Count trailing zeros to find the first encountered invalid character.
- // Bitwise NOT is required once again to flip truthiness.
- // TODO: use .trailing_ones() once MSRV >= 1.46
- (!res).trailing_zeros() as usize
-}
-
-#[test]
-fn avx2_code_matches_uri_chars_table() {
- if !is_x86_feature_detected!("avx2") {
- return;
- }
-
- #[allow(clippy::undocumented_unsafe_blocks)]
- unsafe {
- assert!(byte_is_allowed(b'_', match_uri_vectored));
-
- for (b, allowed) in crate::URI_MAP.iter().cloned().enumerate() {
- assert_eq!(
- byte_is_allowed(b as u8, match_uri_vectored), allowed,
- "byte_is_allowed({:?}) should be {:?}", b, allowed,
- );
- }
- }
-}
-
-#[test]
-fn avx2_code_matches_header_value_chars_table() {
- if !is_x86_feature_detected!("avx2") {
- return;
- }
-
- #[allow(clippy::undocumented_unsafe_blocks)]
- unsafe {
- assert!(byte_is_allowed(b'_', match_header_value_vectored));
-
- for (b, allowed) in crate::HEADER_VALUE_MAP.iter().cloned().enumerate() {
- assert_eq!(
- byte_is_allowed(b as u8, match_header_value_vectored), allowed,
- "byte_is_allowed({:?}) should be {:?}", b, allowed,
- );
- }
- }
-}
-
-#[cfg(test)]
-unsafe fn byte_is_allowed(byte: u8, f: unsafe fn(bytes: &mut Bytes<'_>)) -> bool {
- let slice = [
- b'_', b'_', b'_', b'_',
- b'_', b'_', b'_', b'_',
- b'_', b'_', b'_', b'_',
- b'_', b'_', b'_', b'_',
- b'_', b'_', b'_', b'_',
- b'_', b'_', b'_', b'_',
- b'_', b'_', byte, b'_',
- b'_', b'_', b'_', b'_',
- ];
- let mut bytes = Bytes::new(&slice);
-
- f(&mut bytes);
-
- match bytes.pos() {
- 32 => true,
- 26 => false,
- _ => unreachable!(),
- }
-}
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