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perf: optimize simd escaping for small strings

This commit is contained in:
Kogia-sima 2020-12-19 16:50:28 +09:00
parent 15f397348a
commit c6a3985dfd
3 changed files with 10 additions and 75 deletions
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41
sailfish/src/runtime/escape/avx2.rs
View File

@ -10,20 +10,19 @@ use super::super::Buffer;
use super::{ESCAPED, ESCAPED_LEN, ESCAPE_LUT};
const VECTOR_BYTES: usize = std::mem::size_of::<__m256i>();
const VECTOR_ALIGN: usize = VECTOR_BYTES - 1;
#[target_feature(enable = "avx2")]
pub unsafe fn escape(feed: &str, buffer: &mut Buffer) {
debug_assert!(feed.len() >= 16);
let len = feed.len();
if len < VECTOR_BYTES {
escape_small(feed, buffer);
return;
}
let mut start_ptr = feed.as_ptr();
let mut ptr = start_ptr;
let end_ptr = start_ptr.add(len);
let v_independent1 = _mm256_set1_epi8(5);
@ -38,39 +37,8 @@ pub unsafe fn escape(feed: &str, buffer: &mut Buffer) {
)) as u32
};
let mut ptr = start_ptr;
let aligned_ptr = ptr.add(VECTOR_BYTES - (start_ptr as usize & VECTOR_ALIGN));
{
while ptr <= end_ptr.sub(VECTOR_BYTES) {
let mut mask = maskgen(_mm256_loadu_si256(ptr as *const __m256i));
loop {
let trailing_zeros = mask.trailing_zeros() as usize;
let ptr2 = ptr.add(trailing_zeros);
if ptr2 >= aligned_ptr {
break;
}
let c = ESCAPE_LUT[*ptr2 as usize] as usize;
if c < ESCAPED_LEN {
if start_ptr < ptr2 {
let slc = slice::from_raw_parts(
start_ptr,
ptr2 as usize - start_ptr as usize,
);
buffer.push_str(std::str::from_utf8_unchecked(slc));
}
buffer.push_str(*ESCAPED.get_unchecked(c));
start_ptr = ptr2.add(1);
}
mask ^= 1 << trailing_zeros;
}
}
ptr = aligned_ptr;
let mut next_ptr = ptr.add(VECTOR_BYTES);
while next_ptr <= end_ptr {
let mut mask = maskgen(_mm256_load_si256(ptr as *const __m256i));
while mask != 0 {
let trailing_zeros = mask.trailing_zeros() as usize;
let ptr2 = ptr.add(trailing_zeros);
@ -89,11 +57,10 @@ pub unsafe fn escape(feed: &str, buffer: &mut Buffer) {
mask ^= 1 << trailing_zeros;
}
ptr = next_ptr;
next_ptr = next_ptr.add(VECTOR_BYTES);
ptr = ptr.add(VECTOR_BYTES);
}
debug_assert!(next_ptr > end_ptr);
debug_assert!(ptr.add(VECTOR_BYTES) > end_ptr);
if ptr < end_ptr {
debug_assert!((end_ptr as usize - ptr as usize) < VECTOR_BYTES);

2
sailfish/src/runtime/escape/fallback.rs
View File

@ -58,7 +58,7 @@ pub unsafe fn escape(feed: &str, buffer: &mut Buffer) {
ptr = aligned_ptr;
while ptr.add(USIZE_BYTES) <= end_ptr {
while ptr <= end_ptr.sub(USIZE_BYTES) {
debug_assert_eq!((ptr as usize) % USIZE_BYTES, 0);
let chunk = *(ptr as *const usize);

42
sailfish/src/runtime/escape/sse2.rs
View File

@ -10,12 +10,12 @@ use super::super::Buffer;
use super::{ESCAPED, ESCAPED_LEN, ESCAPE_LUT};
const VECTOR_BYTES: usize = std::mem::size_of::<__m128i>();
const VECTOR_ALIGN: usize = VECTOR_BYTES - 1;
#[target_feature(enable = "sse2")]
pub unsafe fn escape(feed: &str, buffer: &mut Buffer) {
let len = feed.len();
let mut start_ptr = feed.as_ptr();
let mut ptr = start_ptr;
let end_ptr = start_ptr.add(len);
let v_independent1 = _mm_set1_epi8(5);
@ -30,40 +30,9 @@ pub unsafe fn escape(feed: &str, buffer: &mut Buffer) {
)) as u32
};
let mut ptr = start_ptr;
let aligned_ptr = ptr.add(VECTOR_BYTES - (start_ptr as usize & VECTOR_ALIGN));
{
let mut mask = maskgen(_mm_loadu_si128(ptr as *const __m128i));
loop {
let trailing_zeros = mask.trailing_zeros() as usize;
let ptr2 = ptr.add(trailing_zeros);
if ptr2 >= aligned_ptr {
break;
}
let c = ESCAPE_LUT[*ptr2 as usize] as usize;
if c < ESCAPED_LEN {
if start_ptr < ptr2 {
let slc = slice::from_raw_parts(
start_ptr,
ptr2 as usize - start_ptr as usize,
);
buffer.push_str(std::str::from_utf8_unchecked(slc));
}
buffer.push_str(*ESCAPED.get_unchecked(c));
start_ptr = ptr2.add(1);
}
mask ^= 1 << trailing_zeros;
}
}
ptr = aligned_ptr;
let mut next_ptr = ptr.add(VECTOR_BYTES);
while next_ptr <= end_ptr {
while ptr <= end_ptr.sub(VECTOR_BYTES) {
debug_assert_eq!((ptr as usize) % VECTOR_BYTES, 0);
let mut mask = maskgen(_mm_load_si128(ptr as *const __m128i));
let mut mask = maskgen(_mm_loadu_si128(ptr as *const __m128i));
while mask != 0 {
let trailing_zeros = mask.trailing_zeros() as usize;
let ptr2 = ptr.add(trailing_zeros);
@ -82,11 +51,10 @@ pub unsafe fn escape(feed: &str, buffer: &mut Buffer) {
mask ^= 1 << trailing_zeros;
}
ptr = next_ptr;
next_ptr = next_ptr.add(VECTOR_BYTES);
ptr = ptr.add(VECTOR_BYTES);
}
debug_assert!(next_ptr > end_ptr);
debug_assert!(ptr.add(VECTOR_BYTES) > end_ptr);
if ptr < end_ptr {
debug_assert!((end_ptr as usize - ptr as usize) < VECTOR_BYTES);