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#ifndef AWS_CHECKSUMS_PRIVATE_CRC_UTIL_H
#define AWS_CHECKSUMS_PRIVATE_CRC_UTIL_H
/**
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0.
*/
#include <aws/common/byte_order.h>
#include <aws/common/stdint.h>
#include <limits.h>
#include <stdlib.h>
#define large_buffer_apply_impl(Name, T) \
static T aws_large_buffer_apply_##Name( \
T (*checksum_fn)(const uint8_t *, int, T), const uint8_t *buffer, size_t length, T previous) { \
T val = previous; \
while (length > INT_MAX) { \
val = checksum_fn(buffer, INT_MAX, val); \
buffer += (size_t)INT_MAX; \
length -= (size_t)INT_MAX; \
} \
val = checksum_fn(buffer, (int)length, val); \
return val; \
}
/* helper function to reverse byte order on big-endian platforms*/
static inline uint32_t aws_bswap32_if_be(uint32_t x) {
if (!aws_is_big_endian()) {
return x;
}
#if _MSC_VER
return _byteswap_ulong(x);
#elif defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
return __builtin_bswap32(x);
#elif defined(__clang__) && __clang_major__ >= 3
return __builtin_bswap32(x);
#else
return (
((x & 0xff000000u) >> 24) | ((x & 0x00ff0000u) >> 8) | ((x & 0x0000ff00u) << 8) | ((x & 0x000000ffu) << 24));
#endif
}
/* Reverse the bytes in a 64-bit word. */
static inline uint64_t aws_bswap64_if_be(uint64_t x) {
if (!aws_is_big_endian()) {
return x;
}
#if _MSC_VER
return _byteswap_uint64(x);
#elif defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
/* Note: gcc supports it starting with 4.2. here its just picking the lowest version we run test on. */
return __builtin_bswap64(x);
#elif defined(__clang__) && __clang_major__ >= 3
return __builtin_bswap64(x);
#else
return ((x << 56) & 0xff00000000000000ULL) | ((x << 40) & 0x00ff000000000000ULL) |
((x << 24) & 0x0000ff0000000000ULL) | ((x << 8) & 0x000000ff00000000ULL) |
((x >> 8) & 0x00000000ff000000ULL) | ((x >> 24) & 0x0000000000ff0000ULL) |
((x >> 40) & 0x000000000000ff00ULL) | ((x >> 56) & 0x00000000000000ffULL);
#endif
}
#endif /* AWS_CHECKSUMS_PRIVATE_CRC_UTIL_H */
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