mirrors/kitty
1
0
Fork 0
mirror of https://github.com/kovidgoyal/kitty synced 2026-07-13 04:03:16 +02:00
Code Issues Packages Projects Releases Wiki Activity

Use a fast SIMD implementation to XOR data going into the disk cache

Browse Source
This commit is contained in:
Kovid Goyal
2024-02-13 13:18:34 +05:30
parent 88f3c8c5ee
commit ad3ab877f8
5 changed files with 72 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
kitty/simd-string-impl.h
View File

@@ -7,6 +7,7 @@
#pragma once
#include "data-types.h"
#include "simd-string.h"
#include <stdalign.h>
#ifndef KITTY_SIMD_LEVEL
#define KITTY_SIMD_LEVEL 128
@@ -19,6 +20,7 @@
#define NOSIMD { fatal("No SIMD implementations for this CPU"); }
bool FUNC(utf8_decode_to_esc)(UTF8Decoder *d UNUSED, const uint8_t *src UNUSED, size_t src_sz UNUSED) NOSIMD
const uint8_t* FUNC(find_either_of_two_bytes)(const uint8_t *haystack UNUSED, const size_t sz UNUSED, const uint8_t a UNUSED, const uint8_t b UNUSED) NOSIMD
void FUNC(xor_data64)(const uint8_t key[64], uint8_t* data, const size_t data_sz);
#undef NOSIMD
#else
@@ -52,11 +54,13 @@ END_IGNORE_DIAGNOSTIC
#define load_unaligned simde_mm_loadu_si128
#define load_aligned(x) simde_mm_load_si128((const integer_t*)(x))
#define store_unaligned simde_mm_storeu_si128
#define store_aligned(dest, vec) simde_mm_store_si128((integer_t*)dest, vec)
#define cmpeq_epi8 simde_mm_cmpeq_epi8
#define cmplt_epi8 simde_mm_cmplt_epi8
#define cmpgt_epi8 simde_mm_cmpgt_epi8
#define or_si simde_mm_or_si128
#define and_si simde_mm_and_si128
#define xor_si simde_mm_xor_si128
#define andnot_si simde_mm_andnot_si128
#define movemask_epi8 simde_mm_movemask_epi8
#define extract_lower_quarter_as_chars simde_mm_cvtepu8_epi32
@@ -118,11 +122,13 @@ w(left, sixteen_bytes, 16)
#define load_unaligned simde_mm256_loadu_si256
#define load_aligned(x) simde_mm256_load_si256((const integer_t*)(x))
#define store_unaligned simde_mm256_storeu_si256
#define store_aligned(dest, vec) simde_mm256_store_si256((integer_t*)dest, vec)
#define cmpeq_epi8 simde_mm256_cmpeq_epi8
#define cmpgt_epi8 simde_mm256_cmpgt_epi8
#define cmplt_epi8(a, b) cmpgt_epi8(b, a)
#define or_si simde_mm256_or_si256
#define and_si simde_mm256_and_si256
#define xor_si simde_mm256_xor_si256
#define andnot_si simde_mm256_andnot_si256
#define movemask_epi8 simde_mm256_movemask_epi8
#define extract_lower_half_as_chars simde_mm256_cvtepu8_epi32
@@ -307,6 +313,42 @@ zero_last_n_bytes(const integer_t vec, const char n) {
return and_si(mask, vec);
}
#define KEY_SIZE 64
void
FUNC(xor_data64)(const uint8_t key[KEY_SIZE], uint8_t* data, const size_t data_sz) {
// First process unaligned bytes at the start of data
const uintptr_t unaligned_bytes = KEY_SIZE - ((uintptr_t)data & (KEY_SIZE - 1));
if (data_sz <= unaligned_bytes) { for (unsigned i = 0; i < data_sz; i++) data[i] ^= key[i]; return; }
for (unsigned i = 0; i < unaligned_bytes; i++) data[i] ^= key[i];
// Rotate the key by unaligned_bytes
alignas(sizeof(integer_t)) char aligned_key[KEY_SIZE];
memcpy(aligned_key, key + unaligned_bytes, KEY_SIZE - unaligned_bytes);
memcpy(aligned_key + KEY_SIZE - unaligned_bytes, key, unaligned_bytes);
const integer_t v1 = load_aligned(aligned_key), v2 = load_aligned(aligned_key + sizeof(integer_t));
#if KITTY_SIMD_LEVEL == 128
const integer_t v3 = load_aligned(aligned_key + 2*sizeof(integer_t)), v4 = load_aligned(aligned_key + 3 * sizeof(integer_t));
#endif
// Process KEY_SIZE aligned chunks using SIMD
integer_t d;
uint8_t *p = data + unaligned_bytes, *limit = data + data_sz;
const uintptr_t trailing_bytes = (uintptr_t)limit & (KEY_SIZE - 1);
limit -= trailing_bytes;
#define do_one(which) d = load_aligned(p); store_aligned(p, xor_si(which, d)); p += sizeof(integer_t);
while (p < limit) {
do_one(v1); do_one(v2);
#if KITTY_SIMD_LEVEL == 128
do_one(v3); do_one(v4);
#endif
}
#undef do_one
// Process remaining trailing_bytes
for (unsigned i = 0; i < trailing_bytes; i++) limit[i] ^= aligned_key[i];
zero_upper(); return;
}
#undef KEY_SIZE
#define check_chunk() if (n > -1) { \
const uint8_t *ans = haystack + n; \
zero_upper(); \
@@ -716,11 +758,13 @@ start_classification:
#undef load_unaligned
#undef load_aligned
#undef store_unaligned
#undef store_aligned
#undef cmpeq_epi8
#undef cmplt_epi8
#undef cmpgt_epi8
#undef or_si
#undef and_si
#undef xor_si
#undef andnot_si
#undef movemask_epi8
#undef CONCAT