mirror of
https://github.com/Tencent/MMKV.git
synced 2026-10-18 13:10:43 +08:00
guoling
135 lines
3.9 KiB
C++
135 lines
3.9 KiB
C++
/*
|
|
* Tencent is pleased to support the open source community by making
|
|
* MMKV available.
|
|
*
|
|
* Copyright (C) 2020 THL A29 Limited, a Tencent company.
|
|
* All rights reserved.
|
|
*
|
|
* Licensed under the BSD 3-Clause License (the "License"); you may not use
|
|
* this file except in compliance with the License. You may obtain a copy of
|
|
* the License at
|
|
*
|
|
* https://opensource.org/licenses/BSD-3-Clause
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#include "Checksum.h"
|
|
|
|
#ifdef MMKV_USE_ARMV8_CRC32
|
|
|
|
# ifdef CRC32
|
|
// nothing to do
|
|
# elif MMKV_EMBED_ZLIB
|
|
|
|
static inline uint32_t _crc32Wrap(uint32_t crc, const uint8_t *buf, size_t len) {
|
|
return static_cast<uint32_t>(zlib::crc32(crc, buf, static_cast<uInt>(len)));
|
|
}
|
|
|
|
CRC32_Func_t CRC32 = _crc32Wrap;
|
|
|
|
# else
|
|
# include <zlib.h>
|
|
|
|
static inline uint32_t _crc32Wrap(uint32_t crc, const uint8_t *buf, size_t len) {
|
|
return static_cast<uint32_t>(::crc32(crc, buf, static_cast<uInt>(len)));
|
|
}
|
|
|
|
CRC32_Func_t CRC32 = _crc32Wrap;
|
|
|
|
# endif
|
|
|
|
// targeting armv8 with crc instruction extension
|
|
#if defined(__GNUC__) && !defined(__clang__)
|
|
# define TARGET_ARM_CRC __attribute__((target("+crc")))
|
|
# define __builtin_arm_crc32b(a, b) __builtin_aarch64_crc32b(a, b)
|
|
# define __builtin_arm_crc32h(a, b) __builtin_aarch64_crc32h(a, b)
|
|
# define __builtin_arm_crc32w(a, b) __builtin_aarch64_crc32w(a, b)
|
|
# define __builtin_arm_crc32d(a, b) __builtin_aarch64_crc32x(a, b)
|
|
#else
|
|
# define TARGET_ARM_CRC __attribute__((target("crc")))
|
|
#endif
|
|
|
|
TARGET_ARM_CRC static inline uint32_t __crc32b(uint32_t a, uint8_t b) {
|
|
return __builtin_arm_crc32b(a, b);
|
|
}
|
|
|
|
TARGET_ARM_CRC static inline uint32_t __crc32h(uint32_t a, uint16_t b) {
|
|
return __builtin_arm_crc32h(a, b);
|
|
}
|
|
|
|
TARGET_ARM_CRC static inline uint32_t __crc32w(uint32_t a, uint32_t b) {
|
|
return __builtin_arm_crc32w(a, b);
|
|
}
|
|
|
|
TARGET_ARM_CRC static inline uint32_t __crc32d(uint32_t a, uint64_t b) {
|
|
return __builtin_arm_crc32d(a, b);
|
|
}
|
|
|
|
TARGET_ARM_CRC static inline uint32_t armv8_crc32_small(uint32_t crc, const uint8_t *buf, size_t len) {
|
|
if (len >= sizeof(uint32_t)) {
|
|
crc = __crc32w(crc, *(const uint32_t *) buf);
|
|
buf += sizeof(uint32_t);
|
|
len -= sizeof(uint32_t);
|
|
}
|
|
if (len >= sizeof(uint16_t)) {
|
|
crc = __crc32h(crc, *(const uint16_t *) buf);
|
|
buf += sizeof(uint16_t);
|
|
len -= sizeof(uint16_t);
|
|
}
|
|
if (len >= sizeof(uint8_t)) {
|
|
crc = __crc32b(crc, *(const uint8_t *) buf);
|
|
}
|
|
|
|
return crc;
|
|
}
|
|
|
|
namespace mmkv {
|
|
|
|
TARGET_ARM_CRC uint32_t armv8_crc32(uint32_t crc, const uint8_t *buf, size_t len) {
|
|
|
|
crc = crc ^ 0xffffffffUL;
|
|
|
|
// roundup to 8 byte pointer
|
|
auto offset = std::min(len, (uintptr_t) buf & 7);
|
|
if (offset) {
|
|
crc = armv8_crc32_small(crc, buf, offset);
|
|
buf += offset;
|
|
len -= offset;
|
|
}
|
|
if (!len) {
|
|
return crc ^ 0xffffffffUL;
|
|
}
|
|
|
|
// unroll to 8 * 8 byte per loop
|
|
auto ptr64 = (const uint64_t *) buf;
|
|
for (constexpr auto step = 8 * sizeof(uint64_t); len >= step; len -= step) {
|
|
crc = __crc32d(crc, *ptr64++);
|
|
crc = __crc32d(crc, *ptr64++);
|
|
crc = __crc32d(crc, *ptr64++);
|
|
crc = __crc32d(crc, *ptr64++);
|
|
crc = __crc32d(crc, *ptr64++);
|
|
crc = __crc32d(crc, *ptr64++);
|
|
crc = __crc32d(crc, *ptr64++);
|
|
crc = __crc32d(crc, *ptr64++);
|
|
}
|
|
|
|
for (constexpr auto step = sizeof(uint64_t); len >= step; len -= step) {
|
|
crc = __crc32d(crc, *ptr64++);
|
|
}
|
|
|
|
if (len) {
|
|
crc = armv8_crc32_small(crc, (const uint8_t *) ptr64, len);
|
|
}
|
|
|
|
return crc ^ 0xffffffffUL;
|
|
}
|
|
|
|
} // namespace mmkv
|
|
|
|
#endif // MMKV_USE_ARMV8_CRC32
|