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GitHub Repository: Kitware/CMake
Path: blob/master/Utilities/cmzstd/lib/common/xxhash.h
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/*
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* xxHash - Fast Hash algorithm
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* You can contact the author at :
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* - xxHash homepage: https://cyan4973.github.io/xxHash/
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* - xxHash source repository : https://github.com/Cyan4973/xxHash
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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#ifndef XXH_NO_XXH3
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# define XXH_NO_XXH3
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#endif
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#ifndef XXH_NAMESPACE
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# define XXH_NAMESPACE ZSTD_
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#endif
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/*!
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* @mainpage xxHash
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*
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* @file xxhash.h
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* xxHash prototypes and implementation
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*/
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/* TODO: update */
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/* Notice extracted from xxHash homepage:
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xxHash is an extremely fast hash algorithm, running at RAM speed limits.
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It also successfully passes all tests from the SMHasher suite.
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Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
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Name Speed Q.Score Author
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xxHash 5.4 GB/s 10
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CrapWow 3.2 GB/s 2 Andrew
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MurmurHash 3a 2.7 GB/s 10 Austin Appleby
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SpookyHash 2.0 GB/s 10 Bob Jenkins
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SBox 1.4 GB/s 9 Bret Mulvey
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Lookup3 1.2 GB/s 9 Bob Jenkins
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SuperFastHash 1.2 GB/s 1 Paul Hsieh
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CityHash64 1.05 GB/s 10 Pike & Alakuijala
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FNV 0.55 GB/s 5 Fowler, Noll, Vo
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CRC32 0.43 GB/s 9
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MD5-32 0.33 GB/s 10 Ronald L. Rivest
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SHA1-32 0.28 GB/s 10
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Q.Score is a measure of quality of the hash function.
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It depends on successfully passing SMHasher test set.
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10 is a perfect score.
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Note: SMHasher's CRC32 implementation is not the fastest one.
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Other speed-oriented implementations can be faster,
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especially in combination with PCLMUL instruction:
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https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html?showComment=1552696407071#c3490092340461170735
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A 64-bit version, named XXH64, is available since r35.
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It offers much better speed, but for 64-bit applications only.
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Name Speed on 64 bits Speed on 32 bits
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XXH64 13.8 GB/s 1.9 GB/s
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XXH32 6.8 GB/s 6.0 GB/s
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*/
67
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#if defined (__cplusplus)
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extern "C" {
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#endif
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/* ****************************
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* INLINE mode
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******************************/
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/*!
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* XXH_INLINE_ALL (and XXH_PRIVATE_API)
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* Use these build macros to inline xxhash into the target unit.
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* Inlining improves performance on small inputs, especially when the length is
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* expressed as a compile-time constant:
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*
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* https://fastcompression.blogspot.com/2018/03/xxhash-for-small-keys-impressive-power.html
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*
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* It also keeps xxHash symbols private to the unit, so they are not exported.
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*
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* Usage:
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* #define XXH_INLINE_ALL
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* #include "xxhash.h"
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*
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* Do not compile and link xxhash.o as a separate object, as it is not useful.
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*/
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#if (defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)) \
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&& !defined(XXH_INLINE_ALL_31684351384)
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/* this section should be traversed only once */
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# define XXH_INLINE_ALL_31684351384
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/* give access to the advanced API, required to compile implementations */
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# undef XXH_STATIC_LINKING_ONLY /* avoid macro redef */
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# define XXH_STATIC_LINKING_ONLY
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/* make all functions private */
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# undef XXH_PUBLIC_API
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# if defined(__GNUC__)
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# define XXH_PUBLIC_API static __inline __attribute__((unused))
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# elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
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# define XXH_PUBLIC_API static inline
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# elif defined(_MSC_VER)
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# define XXH_PUBLIC_API static __inline
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# else
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/* note: this version may generate warnings for unused static functions */
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# define XXH_PUBLIC_API static
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# endif
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/*
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* This part deals with the special case where a unit wants to inline xxHash,
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* but "xxhash.h" has previously been included without XXH_INLINE_ALL,
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* such as part of some previously included *.h header file.
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* Without further action, the new include would just be ignored,
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* and functions would effectively _not_ be inlined (silent failure).
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* The following macros solve this situation by prefixing all inlined names,
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* avoiding naming collision with previous inclusions.
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*/
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/* Before that, we unconditionally #undef all symbols,
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* in case they were already defined with XXH_NAMESPACE.
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* They will then be redefined for XXH_INLINE_ALL
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*/
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# undef XXH_versionNumber
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/* XXH32 */
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# undef XXH32
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# undef XXH32_createState
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# undef XXH32_freeState
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# undef XXH32_reset
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# undef XXH32_update
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# undef XXH32_digest
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# undef XXH32_copyState
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# undef XXH32_canonicalFromHash
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# undef XXH32_hashFromCanonical
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/* XXH64 */
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# undef XXH64
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# undef XXH64_createState
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# undef XXH64_freeState
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# undef XXH64_reset
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# undef XXH64_update
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# undef XXH64_digest
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# undef XXH64_copyState
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# undef XXH64_canonicalFromHash
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# undef XXH64_hashFromCanonical
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/* XXH3_64bits */
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# undef XXH3_64bits
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# undef XXH3_64bits_withSecret
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# undef XXH3_64bits_withSeed
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# undef XXH3_64bits_withSecretandSeed
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# undef XXH3_createState
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# undef XXH3_freeState
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# undef XXH3_copyState
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# undef XXH3_64bits_reset
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# undef XXH3_64bits_reset_withSeed
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# undef XXH3_64bits_reset_withSecret
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# undef XXH3_64bits_update
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# undef XXH3_64bits_digest
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# undef XXH3_generateSecret
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/* XXH3_128bits */
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# undef XXH128
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# undef XXH3_128bits
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# undef XXH3_128bits_withSeed
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# undef XXH3_128bits_withSecret
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# undef XXH3_128bits_reset
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# undef XXH3_128bits_reset_withSeed
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# undef XXH3_128bits_reset_withSecret
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# undef XXH3_128bits_reset_withSecretandSeed
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# undef XXH3_128bits_update
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# undef XXH3_128bits_digest
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# undef XXH128_isEqual
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# undef XXH128_cmp
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# undef XXH128_canonicalFromHash
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# undef XXH128_hashFromCanonical
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/* Finally, free the namespace itself */
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# undef XXH_NAMESPACE
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/* employ the namespace for XXH_INLINE_ALL */
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# define XXH_NAMESPACE XXH_INLINE_
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/*
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* Some identifiers (enums, type names) are not symbols,
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* but they must nonetheless be renamed to avoid redeclaration.
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* Alternative solution: do not redeclare them.
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* However, this requires some #ifdefs, and has a more dispersed impact.
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* Meanwhile, renaming can be achieved in a single place.
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*/
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# define XXH_IPREF(Id) XXH_NAMESPACE ## Id
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# define XXH_OK XXH_IPREF(XXH_OK)
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# define XXH_ERROR XXH_IPREF(XXH_ERROR)
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# define XXH_errorcode XXH_IPREF(XXH_errorcode)
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# define XXH32_canonical_t XXH_IPREF(XXH32_canonical_t)
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# define XXH64_canonical_t XXH_IPREF(XXH64_canonical_t)
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# define XXH128_canonical_t XXH_IPREF(XXH128_canonical_t)
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# define XXH32_state_s XXH_IPREF(XXH32_state_s)
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# define XXH32_state_t XXH_IPREF(XXH32_state_t)
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# define XXH64_state_s XXH_IPREF(XXH64_state_s)
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# define XXH64_state_t XXH_IPREF(XXH64_state_t)
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# define XXH3_state_s XXH_IPREF(XXH3_state_s)
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# define XXH3_state_t XXH_IPREF(XXH3_state_t)
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# define XXH128_hash_t XXH_IPREF(XXH128_hash_t)
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/* Ensure the header is parsed again, even if it was previously included */
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# undef XXHASH_H_5627135585666179
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# undef XXHASH_H_STATIC_13879238742
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#endif /* XXH_INLINE_ALL || XXH_PRIVATE_API */
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/* ****************************************************************
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* Stable API
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*****************************************************************/
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#ifndef XXHASH_H_5627135585666179
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#define XXHASH_H_5627135585666179 1
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213
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/*!
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* @defgroup public Public API
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* Contains details on the public xxHash functions.
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* @{
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*/
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/* specific declaration modes for Windows */
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#if !defined(XXH_INLINE_ALL) && !defined(XXH_PRIVATE_API)
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# if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
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# ifdef XXH_EXPORT
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# define XXH_PUBLIC_API __declspec(dllexport)
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# elif XXH_IMPORT
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# define XXH_PUBLIC_API __declspec(dllimport)
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# endif
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# else
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# define XXH_PUBLIC_API /* do nothing */
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# endif
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#endif
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#ifdef XXH_DOXYGEN
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/*!
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* @brief Emulate a namespace by transparently prefixing all symbols.
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*
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* If you want to include _and expose_ xxHash functions from within your own
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* library, but also want to avoid symbol collisions with other libraries which
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* may also include xxHash, you can use XXH_NAMESPACE to automatically prefix
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* any public symbol from xxhash library with the value of XXH_NAMESPACE
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* (therefore, avoid empty or numeric values).
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*
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* Note that no change is required within the calling program as long as it
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* includes `xxhash.h`: Regular symbol names will be automatically translated
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* by this header.
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*/
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# define XXH_NAMESPACE /* YOUR NAME HERE */
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# undef XXH_NAMESPACE
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#endif
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#ifdef XXH_NAMESPACE
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# define XXH_CAT(A,B) A##B
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# define XXH_NAME2(A,B) XXH_CAT(A,B)
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# define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
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/* XXH32 */
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# define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
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# define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
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# define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
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# define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
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# define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
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# define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
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# define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
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# define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
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# define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
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/* XXH64 */
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# define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
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# define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
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# define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
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# define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
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# define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
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# define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
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# define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
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# define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
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# define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
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/* XXH3_64bits */
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# define XXH3_64bits XXH_NAME2(XXH_NAMESPACE, XXH3_64bits)
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# define XXH3_64bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSecret)
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# define XXH3_64bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSeed)
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# define XXH3_64bits_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSecretandSeed)
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# define XXH3_createState XXH_NAME2(XXH_NAMESPACE, XXH3_createState)
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# define XXH3_freeState XXH_NAME2(XXH_NAMESPACE, XXH3_freeState)
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# define XXH3_copyState XXH_NAME2(XXH_NAMESPACE, XXH3_copyState)
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# define XXH3_64bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset)
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# define XXH3_64bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSeed)
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# define XXH3_64bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSecret)
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# define XXH3_64bits_reset_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSecretandSeed)
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# define XXH3_64bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_update)
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# define XXH3_64bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_digest)
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# define XXH3_generateSecret XXH_NAME2(XXH_NAMESPACE, XXH3_generateSecret)
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# define XXH3_generateSecret_fromSeed XXH_NAME2(XXH_NAMESPACE, XXH3_generateSecret_fromSeed)
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/* XXH3_128bits */
291
# define XXH128 XXH_NAME2(XXH_NAMESPACE, XXH128)
292
# define XXH3_128bits XXH_NAME2(XXH_NAMESPACE, XXH3_128bits)
293
# define XXH3_128bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSeed)
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# define XXH3_128bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSecret)
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# define XXH3_128bits_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSecretandSeed)
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# define XXH3_128bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset)
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# define XXH3_128bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSeed)
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# define XXH3_128bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSecret)
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# define XXH3_128bits_reset_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSecretandSeed)
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# define XXH3_128bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_update)
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# define XXH3_128bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_digest)
302
# define XXH128_isEqual XXH_NAME2(XXH_NAMESPACE, XXH128_isEqual)
303
# define XXH128_cmp XXH_NAME2(XXH_NAMESPACE, XXH128_cmp)
304
# define XXH128_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH128_canonicalFromHash)
305
# define XXH128_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH128_hashFromCanonical)
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#endif
307
308
309
/* *************************************
310
* Version
311
***************************************/
312
#define XXH_VERSION_MAJOR 0
313
#define XXH_VERSION_MINOR 8
314
#define XXH_VERSION_RELEASE 1
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#define XXH_VERSION_NUMBER (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)
316
317
/*!
318
* @brief Obtains the xxHash version.
319
*
320
* This is mostly useful when xxHash is compiled as a shared library,
321
* since the returned value comes from the library, as opposed to header file.
322
*
323
* @return `XXH_VERSION_NUMBER` of the invoked library.
324
*/
325
XXH_PUBLIC_API unsigned XXH_versionNumber (void);
326
327
328
/* ****************************
329
* Common basic types
330
******************************/
331
#include <stddef.h> /* size_t */
332
typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
333
334
335
/*-**********************************************************************
336
* 32-bit hash
337
************************************************************************/
338
#if defined(XXH_DOXYGEN) /* Don't show <stdint.h> include */
339
/*!
340
* @brief An unsigned 32-bit integer.
341
*
342
* Not necessarily defined to `uint32_t` but functionally equivalent.
343
*/
344
typedef uint32_t XXH32_hash_t;
345
346
#elif !defined (__VMS) \
347
&& (defined (__cplusplus) \
348
|| (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
349
# include <stdint.h>
350
typedef uint32_t XXH32_hash_t;
351
352
#else
353
# include <limits.h>
354
# if UINT_MAX == 0xFFFFFFFFUL
355
typedef unsigned int XXH32_hash_t;
356
# else
357
# if ULONG_MAX == 0xFFFFFFFFUL
358
typedef unsigned long XXH32_hash_t;
359
# else
360
# error "unsupported platform: need a 32-bit type"
361
# endif
362
# endif
363
#endif
364
365
/*!
366
* @}
367
*
368
* @defgroup xxh32_family XXH32 family
369
* @ingroup public
370
* Contains functions used in the classic 32-bit xxHash algorithm.
371
*
372
* @note
373
* XXH32 is useful for older platforms, with no or poor 64-bit performance.
374
* Note that @ref xxh3_family provides competitive speed
375
* for both 32-bit and 64-bit systems, and offers true 64/128 bit hash results.
376
*
377
* @see @ref xxh64_family, @ref xxh3_family : Other xxHash families
378
* @see @ref xxh32_impl for implementation details
379
* @{
380
*/
381
382
/*!
383
* @brief Calculates the 32-bit hash of @p input using xxHash32.
384
*
385
* Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark): 5.4 GB/s
386
*
387
* @param input The block of data to be hashed, at least @p length bytes in size.
388
* @param length The length of @p input, in bytes.
389
* @param seed The 32-bit seed to alter the hash's output predictably.
390
*
391
* @pre
392
* The memory between @p input and @p input + @p length must be valid,
393
* readable, contiguous memory. However, if @p length is `0`, @p input may be
394
* `NULL`. In C++, this also must be *TriviallyCopyable*.
395
*
396
* @return The calculated 32-bit hash value.
397
*
398
* @see
399
* XXH64(), XXH3_64bits_withSeed(), XXH3_128bits_withSeed(), XXH128():
400
* Direct equivalents for the other variants of xxHash.
401
* @see
402
* XXH32_createState(), XXH32_update(), XXH32_digest(): Streaming version.
403
*/
404
XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, XXH32_hash_t seed);
405
406
/*!
407
* Streaming functions generate the xxHash value from an incremental input.
408
* This method is slower than single-call functions, due to state management.
409
* For small inputs, prefer `XXH32()` and `XXH64()`, which are better optimized.
410
*
411
* An XXH state must first be allocated using `XXH*_createState()`.
412
*
413
* Start a new hash by initializing the state with a seed using `XXH*_reset()`.
414
*
415
* Then, feed the hash state by calling `XXH*_update()` as many times as necessary.
416
*
417
* The function returns an error code, with 0 meaning OK, and any other value
418
* meaning there is an error.
419
*
420
* Finally, a hash value can be produced anytime, by using `XXH*_digest()`.
421
* This function returns the nn-bits hash as an int or long long.
422
*
423
* It's still possible to continue inserting input into the hash state after a
424
* digest, and generate new hash values later on by invoking `XXH*_digest()`.
425
*
426
* When done, release the state using `XXH*_freeState()`.
427
*
428
* Example code for incrementally hashing a file:
429
* @code{.c}
430
* #include <stdio.h>
431
* #include <xxhash.h>
432
* #define BUFFER_SIZE 256
433
*
434
* // Note: XXH64 and XXH3 use the same interface.
435
* XXH32_hash_t
436
* hashFile(FILE* stream)
437
* {
438
* XXH32_state_t* state;
439
* unsigned char buf[BUFFER_SIZE];
440
* size_t amt;
441
* XXH32_hash_t hash;
442
*
443
* state = XXH32_createState(); // Create a state
444
* assert(state != NULL); // Error check here
445
* XXH32_reset(state, 0xbaad5eed); // Reset state with our seed
446
* while ((amt = fread(buf, 1, sizeof(buf), stream)) != 0) {
447
* XXH32_update(state, buf, amt); // Hash the file in chunks
448
* }
449
* hash = XXH32_digest(state); // Finalize the hash
450
* XXH32_freeState(state); // Clean up
451
* return hash;
452
* }
453
* @endcode
454
*/
455
456
/*!
457
* @typedef struct XXH32_state_s XXH32_state_t
458
* @brief The opaque state struct for the XXH32 streaming API.
459
*
460
* @see XXH32_state_s for details.
461
*/
462
typedef struct XXH32_state_s XXH32_state_t;
463
464
/*!
465
* @brief Allocates an @ref XXH32_state_t.
466
*
467
* Must be freed with XXH32_freeState().
468
* @return An allocated XXH32_state_t on success, `NULL` on failure.
469
*/
470
XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
471
/*!
472
* @brief Frees an @ref XXH32_state_t.
473
*
474
* Must be allocated with XXH32_createState().
475
* @param statePtr A pointer to an @ref XXH32_state_t allocated with @ref XXH32_createState().
476
* @return XXH_OK.
477
*/
478
XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr);
479
/*!
480
* @brief Copies one @ref XXH32_state_t to another.
481
*
482
* @param dst_state The state to copy to.
483
* @param src_state The state to copy from.
484
* @pre
485
* @p dst_state and @p src_state must not be `NULL` and must not overlap.
486
*/
487
XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dst_state, const XXH32_state_t* src_state);
488
489
/*!
490
* @brief Resets an @ref XXH32_state_t to begin a new hash.
491
*
492
* This function resets and seeds a state. Call it before @ref XXH32_update().
493
*
494
* @param statePtr The state struct to reset.
495
* @param seed The 32-bit seed to alter the hash result predictably.
496
*
497
* @pre
498
* @p statePtr must not be `NULL`.
499
*
500
* @return @ref XXH_OK on success, @ref XXH_ERROR on failure.
501
*/
502
XXH_PUBLIC_API XXH_errorcode XXH32_reset (XXH32_state_t* statePtr, XXH32_hash_t seed);
503
504
/*!
505
* @brief Consumes a block of @p input to an @ref XXH32_state_t.
506
*
507
* Call this to incrementally consume blocks of data.
508
*
509
* @param statePtr The state struct to update.
510
* @param input The block of data to be hashed, at least @p length bytes in size.
511
* @param length The length of @p input, in bytes.
512
*
513
* @pre
514
* @p statePtr must not be `NULL`.
515
* @pre
516
* The memory between @p input and @p input + @p length must be valid,
517
* readable, contiguous memory. However, if @p length is `0`, @p input may be
518
* `NULL`. In C++, this also must be *TriviallyCopyable*.
519
*
520
* @return @ref XXH_OK on success, @ref XXH_ERROR on failure.
521
*/
522
XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
523
524
/*!
525
* @brief Returns the calculated hash value from an @ref XXH32_state_t.
526
*
527
* @note
528
* Calling XXH32_digest() will not affect @p statePtr, so you can update,
529
* digest, and update again.
530
*
531
* @param statePtr The state struct to calculate the hash from.
532
*
533
* @pre
534
* @p statePtr must not be `NULL`.
535
*
536
* @return The calculated xxHash32 value from that state.
537
*/
538
XXH_PUBLIC_API XXH32_hash_t XXH32_digest (const XXH32_state_t* statePtr);
539
540
/******* Canonical representation *******/
541
542
/*
543
* The default return values from XXH functions are unsigned 32 and 64 bit
544
* integers.
545
* This the simplest and fastest format for further post-processing.
546
*
547
* However, this leaves open the question of what is the order on the byte level,
548
* since little and big endian conventions will store the same number differently.
549
*
550
* The canonical representation settles this issue by mandating big-endian
551
* convention, the same convention as human-readable numbers (large digits first).
552
*
553
* When writing hash values to storage, sending them over a network, or printing
554
* them, it's highly recommended to use the canonical representation to ensure
555
* portability across a wider range of systems, present and future.
556
*
557
* The following functions allow transformation of hash values to and from
558
* canonical format.
559
*/
560
561
/*!
562
* @brief Canonical (big endian) representation of @ref XXH32_hash_t.
563
*/
564
typedef struct {
565
unsigned char digest[4]; /*!< Hash bytes, big endian */
566
} XXH32_canonical_t;
567
568
/*!
569
* @brief Converts an @ref XXH32_hash_t to a big endian @ref XXH32_canonical_t.
570
*
571
* @param dst The @ref XXH32_canonical_t pointer to be stored to.
572
* @param hash The @ref XXH32_hash_t to be converted.
573
*
574
* @pre
575
* @p dst must not be `NULL`.
576
*/
577
XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);
578
579
/*!
580
* @brief Converts an @ref XXH32_canonical_t to a native @ref XXH32_hash_t.
581
*
582
* @param src The @ref XXH32_canonical_t to convert.
583
*
584
* @pre
585
* @p src must not be `NULL`.
586
*
587
* @return The converted hash.
588
*/
589
XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
590
591
592
#ifdef __has_attribute
593
# define XXH_HAS_ATTRIBUTE(x) __has_attribute(x)
594
#else
595
# define XXH_HAS_ATTRIBUTE(x) 0
596
#endif
597
598
/* C-language Attributes are added in C23. */
599
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute)
600
# define XXH_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
601
#else
602
# define XXH_HAS_C_ATTRIBUTE(x) 0
603
#endif
604
605
#if defined(__cplusplus) && defined(__has_cpp_attribute)
606
# define XXH_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
607
#else
608
# define XXH_HAS_CPP_ATTRIBUTE(x) 0
609
#endif
610
611
/*
612
Define XXH_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute
613
introduced in CPP17 and C23.
614
CPP17 : https://en.cppreference.com/w/cpp/language/attributes/fallthrough
615
C23 : https://en.cppreference.com/w/c/language/attributes/fallthrough
616
*/
617
#if XXH_HAS_C_ATTRIBUTE(x)
618
# define XXH_FALLTHROUGH [[fallthrough]]
619
#elif XXH_HAS_CPP_ATTRIBUTE(x)
620
# define XXH_FALLTHROUGH [[fallthrough]]
621
#elif XXH_HAS_ATTRIBUTE(__fallthrough__)
622
# define XXH_FALLTHROUGH __attribute__ ((fallthrough))
623
#else
624
# define XXH_FALLTHROUGH
625
#endif
626
627
/*!
628
* @}
629
* @ingroup public
630
* @{
631
*/
632
633
#ifndef XXH_NO_LONG_LONG
634
/*-**********************************************************************
635
* 64-bit hash
636
************************************************************************/
637
#if defined(XXH_DOXYGEN) /* don't include <stdint.h> */
638
/*!
639
* @brief An unsigned 64-bit integer.
640
*
641
* Not necessarily defined to `uint64_t` but functionally equivalent.
642
*/
643
typedef uint64_t XXH64_hash_t;
644
#elif !defined (__VMS) \
645
&& (defined (__cplusplus) \
646
|| (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
647
# include <stdint.h>
648
typedef uint64_t XXH64_hash_t;
649
#else
650
# include <limits.h>
651
# if defined(__LP64__) && ULONG_MAX == 0xFFFFFFFFFFFFFFFFULL
652
/* LP64 ABI says uint64_t is unsigned long */
653
typedef unsigned long XXH64_hash_t;
654
# else
655
/* the following type must have a width of 64-bit */
656
typedef unsigned long long XXH64_hash_t;
657
# endif
658
#endif
659
660
/*!
661
* @}
662
*
663
* @defgroup xxh64_family XXH64 family
664
* @ingroup public
665
* @{
666
* Contains functions used in the classic 64-bit xxHash algorithm.
667
*
668
* @note
669
* XXH3 provides competitive speed for both 32-bit and 64-bit systems,
670
* and offers true 64/128 bit hash results.
671
* It provides better speed for systems with vector processing capabilities.
672
*/
673
674
675
/*!
676
* @brief Calculates the 64-bit hash of @p input using xxHash64.
677
*
678
* This function usually runs faster on 64-bit systems, but slower on 32-bit
679
* systems (see benchmark).
680
*
681
* @param input The block of data to be hashed, at least @p length bytes in size.
682
* @param length The length of @p input, in bytes.
683
* @param seed The 64-bit seed to alter the hash's output predictably.
684
*
685
* @pre
686
* The memory between @p input and @p input + @p length must be valid,
687
* readable, contiguous memory. However, if @p length is `0`, @p input may be
688
* `NULL`. In C++, this also must be *TriviallyCopyable*.
689
*
690
* @return The calculated 64-bit hash.
691
*
692
* @see
693
* XXH32(), XXH3_64bits_withSeed(), XXH3_128bits_withSeed(), XXH128():
694
* Direct equivalents for the other variants of xxHash.
695
* @see
696
* XXH64_createState(), XXH64_update(), XXH64_digest(): Streaming version.
697
*/
698
XXH_PUBLIC_API XXH64_hash_t XXH64(const void* input, size_t length, XXH64_hash_t seed);
699
700
/******* Streaming *******/
701
/*!
702
* @brief The opaque state struct for the XXH64 streaming API.
703
*
704
* @see XXH64_state_s for details.
705
*/
706
typedef struct XXH64_state_s XXH64_state_t; /* incomplete type */
707
XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);
708
XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr);
709
XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dst_state, const XXH64_state_t* src_state);
710
711
XXH_PUBLIC_API XXH_errorcode XXH64_reset (XXH64_state_t* statePtr, XXH64_hash_t seed);
712
XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
713
XXH_PUBLIC_API XXH64_hash_t XXH64_digest (const XXH64_state_t* statePtr);
714
715
/******* Canonical representation *******/
716
typedef struct { unsigned char digest[sizeof(XXH64_hash_t)]; } XXH64_canonical_t;
717
XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
718
XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
719
720
#ifndef XXH_NO_XXH3
721
/*!
722
* @}
723
* ************************************************************************
724
* @defgroup xxh3_family XXH3 family
725
* @ingroup public
726
* @{
727
*
728
* XXH3 is a more recent hash algorithm featuring:
729
* - Improved speed for both small and large inputs
730
* - True 64-bit and 128-bit outputs
731
* - SIMD acceleration
732
* - Improved 32-bit viability
733
*
734
* Speed analysis methodology is explained here:
735
*
736
* https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html
737
*
738
* Compared to XXH64, expect XXH3 to run approximately
739
* ~2x faster on large inputs and >3x faster on small ones,
740
* exact differences vary depending on platform.
741
*
742
* XXH3's speed benefits greatly from SIMD and 64-bit arithmetic,
743
* but does not require it.
744
* Any 32-bit and 64-bit targets that can run XXH32 smoothly
745
* can run XXH3 at competitive speeds, even without vector support.
746
* Further details are explained in the implementation.
747
*
748
* Optimized implementations are provided for AVX512, AVX2, SSE2, NEON, POWER8,
749
* ZVector and scalar targets. This can be controlled via the XXH_VECTOR macro.
750
*
751
* XXH3 implementation is portable:
752
* it has a generic C90 formulation that can be compiled on any platform,
753
* all implementations generage exactly the same hash value on all platforms.
754
* Starting from v0.8.0, it's also labelled "stable", meaning that
755
* any future version will also generate the same hash value.
756
*
757
* XXH3 offers 2 variants, _64bits and _128bits.
758
*
759
* When only 64 bits are needed, prefer invoking the _64bits variant, as it
760
* reduces the amount of mixing, resulting in faster speed on small inputs.
761
* It's also generally simpler to manipulate a scalar return type than a struct.
762
*
763
* The API supports one-shot hashing, streaming mode, and custom secrets.
764
*/
765
766
/*-**********************************************************************
767
* XXH3 64-bit variant
768
************************************************************************/
769
770
/* XXH3_64bits():
771
* default 64-bit variant, using default secret and default seed of 0.
772
* It's the fastest variant. */
773
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(const void* data, size_t len);
774
775
/*
776
* XXH3_64bits_withSeed():
777
* This variant generates a custom secret on the fly
778
* based on default secret altered using the `seed` value.
779
* While this operation is decently fast, note that it's not completely free.
780
* Note: seed==0 produces the same results as XXH3_64bits().
781
*/
782
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_withSeed(const void* data, size_t len, XXH64_hash_t seed);
783
784
/*!
785
* The bare minimum size for a custom secret.
786
*
787
* @see
788
* XXH3_64bits_withSecret(), XXH3_64bits_reset_withSecret(),
789
* XXH3_128bits_withSecret(), XXH3_128bits_reset_withSecret().
790
*/
791
#define XXH3_SECRET_SIZE_MIN 136
792
793
/*
794
* XXH3_64bits_withSecret():
795
* It's possible to provide any blob of bytes as a "secret" to generate the hash.
796
* This makes it more difficult for an external actor to prepare an intentional collision.
797
* The main condition is that secretSize *must* be large enough (>= XXH3_SECRET_SIZE_MIN).
798
* However, the quality of the secret impacts the dispersion of the hash algorithm.
799
* Therefore, the secret _must_ look like a bunch of random bytes.
800
* Avoid "trivial" or structured data such as repeated sequences or a text document.
801
* Whenever in doubt about the "randomness" of the blob of bytes,
802
* consider employing "XXH3_generateSecret()" instead (see below).
803
* It will generate a proper high entropy secret derived from the blob of bytes.
804
* Another advantage of using XXH3_generateSecret() is that
805
* it guarantees that all bits within the initial blob of bytes
806
* will impact every bit of the output.
807
* This is not necessarily the case when using the blob of bytes directly
808
* because, when hashing _small_ inputs, only a portion of the secret is employed.
809
*/
810
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_withSecret(const void* data, size_t len, const void* secret, size_t secretSize);
811
812
813
/******* Streaming *******/
814
/*
815
* Streaming requires state maintenance.
816
* This operation costs memory and CPU.
817
* As a consequence, streaming is slower than one-shot hashing.
818
* For better performance, prefer one-shot functions whenever applicable.
819
*/
820
821
/*!
822
* @brief The state struct for the XXH3 streaming API.
823
*
824
* @see XXH3_state_s for details.
825
*/
826
typedef struct XXH3_state_s XXH3_state_t;
827
XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void);
828
XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr);
829
XXH_PUBLIC_API void XXH3_copyState(XXH3_state_t* dst_state, const XXH3_state_t* src_state);
830
831
/*
832
* XXH3_64bits_reset():
833
* Initialize with default parameters.
834
* digest will be equivalent to `XXH3_64bits()`.
835
*/
836
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset(XXH3_state_t* statePtr);
837
/*
838
* XXH3_64bits_reset_withSeed():
839
* Generate a custom secret from `seed`, and store it into `statePtr`.
840
* digest will be equivalent to `XXH3_64bits_withSeed()`.
841
*/
842
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed);
843
/*
844
* XXH3_64bits_reset_withSecret():
845
* `secret` is referenced, it _must outlive_ the hash streaming session.
846
* Similar to one-shot API, `secretSize` must be >= `XXH3_SECRET_SIZE_MIN`,
847
* and the quality of produced hash values depends on secret's entropy
848
* (secret's content should look like a bunch of random bytes).
849
* When in doubt about the randomness of a candidate `secret`,
850
* consider employing `XXH3_generateSecret()` instead (see below).
851
*/
852
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize);
853
854
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_update (XXH3_state_t* statePtr, const void* input, size_t length);
855
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_digest (const XXH3_state_t* statePtr);
856
857
/* note : canonical representation of XXH3 is the same as XXH64
858
* since they both produce XXH64_hash_t values */
859
860
861
/*-**********************************************************************
862
* XXH3 128-bit variant
863
************************************************************************/
864
865
/*!
866
* @brief The return value from 128-bit hashes.
867
*
868
* Stored in little endian order, although the fields themselves are in native
869
* endianness.
870
*/
871
typedef struct {
872
XXH64_hash_t low64; /*!< `value & 0xFFFFFFFFFFFFFFFF` */
873
XXH64_hash_t high64; /*!< `value >> 64` */
874
} XXH128_hash_t;
875
876
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(const void* data, size_t len);
877
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_withSeed(const void* data, size_t len, XXH64_hash_t seed);
878
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_withSecret(const void* data, size_t len, const void* secret, size_t secretSize);
879
880
/******* Streaming *******/
881
/*
882
* Streaming requires state maintenance.
883
* This operation costs memory and CPU.
884
* As a consequence, streaming is slower than one-shot hashing.
885
* For better performance, prefer one-shot functions whenever applicable.
886
*
887
* XXH3_128bits uses the same XXH3_state_t as XXH3_64bits().
888
* Use already declared XXH3_createState() and XXH3_freeState().
889
*
890
* All reset and streaming functions have same meaning as their 64-bit counterpart.
891
*/
892
893
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset(XXH3_state_t* statePtr);
894
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed);
895
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize);
896
897
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_update (XXH3_state_t* statePtr, const void* input, size_t length);
898
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (const XXH3_state_t* statePtr);
899
900
/* Following helper functions make it possible to compare XXH128_hast_t values.
901
* Since XXH128_hash_t is a structure, this capability is not offered by the language.
902
* Note: For better performance, these functions can be inlined using XXH_INLINE_ALL */
903
904
/*!
905
* XXH128_isEqual():
906
* Return: 1 if `h1` and `h2` are equal, 0 if they are not.
907
*/
908
XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2);
909
910
/*!
911
* XXH128_cmp():
912
*
913
* This comparator is compatible with stdlib's `qsort()`/`bsearch()`.
914
*
915
* return: >0 if *h128_1 > *h128_2
916
* =0 if *h128_1 == *h128_2
917
* <0 if *h128_1 < *h128_2
918
*/
919
XXH_PUBLIC_API int XXH128_cmp(const void* h128_1, const void* h128_2);
920
921
922
/******* Canonical representation *******/
923
typedef struct { unsigned char digest[sizeof(XXH128_hash_t)]; } XXH128_canonical_t;
924
XXH_PUBLIC_API void XXH128_canonicalFromHash(XXH128_canonical_t* dst, XXH128_hash_t hash);
925
XXH_PUBLIC_API XXH128_hash_t XXH128_hashFromCanonical(const XXH128_canonical_t* src);
926
927
928
#endif /* !XXH_NO_XXH3 */
929
#endif /* XXH_NO_LONG_LONG */
930
931
/*!
932
* @}
933
*/
934
#endif /* XXHASH_H_5627135585666179 */
935
936
937
938
#if defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742)
939
#define XXHASH_H_STATIC_13879238742
940
/* ****************************************************************************
941
* This section contains declarations which are not guaranteed to remain stable.
942
* They may change in future versions, becoming incompatible with a different
943
* version of the library.
944
* These declarations should only be used with static linking.
945
* Never use them in association with dynamic linking!
946
***************************************************************************** */
947
948
/*
949
* These definitions are only present to allow static allocation
950
* of XXH states, on stack or in a struct, for example.
951
* Never **ever** access their members directly.
952
*/
953
954
/*!
955
* @internal
956
* @brief Structure for XXH32 streaming API.
957
*
958
* @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
959
* @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
960
* an opaque type. This allows fields to safely be changed.
961
*
962
* Typedef'd to @ref XXH32_state_t.
963
* Do not access the members of this struct directly.
964
* @see XXH64_state_s, XXH3_state_s
965
*/
966
struct XXH32_state_s {
967
XXH32_hash_t total_len_32; /*!< Total length hashed, modulo 2^32 */
968
XXH32_hash_t large_len; /*!< Whether the hash is >= 16 (handles @ref total_len_32 overflow) */
969
XXH32_hash_t v[4]; /*!< Accumulator lanes */
970
XXH32_hash_t mem32[4]; /*!< Internal buffer for partial reads. Treated as unsigned char[16]. */
971
XXH32_hash_t memsize; /*!< Amount of data in @ref mem32 */
972
XXH32_hash_t reserved; /*!< Reserved field. Do not read nor write to it. */
973
}; /* typedef'd to XXH32_state_t */
974
975
976
#ifndef XXH_NO_LONG_LONG /* defined when there is no 64-bit support */
977
978
/*!
979
* @internal
980
* @brief Structure for XXH64 streaming API.
981
*
982
* @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
983
* @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
984
* an opaque type. This allows fields to safely be changed.
985
*
986
* Typedef'd to @ref XXH64_state_t.
987
* Do not access the members of this struct directly.
988
* @see XXH32_state_s, XXH3_state_s
989
*/
990
struct XXH64_state_s {
991
XXH64_hash_t total_len; /*!< Total length hashed. This is always 64-bit. */
992
XXH64_hash_t v[4]; /*!< Accumulator lanes */
993
XXH64_hash_t mem64[4]; /*!< Internal buffer for partial reads. Treated as unsigned char[32]. */
994
XXH32_hash_t memsize; /*!< Amount of data in @ref mem64 */
995
XXH32_hash_t reserved32; /*!< Reserved field, needed for padding anyways*/
996
XXH64_hash_t reserved64; /*!< Reserved field. Do not read or write to it. */
997
}; /* typedef'd to XXH64_state_t */
998
999
1000
#ifndef XXH_NO_XXH3
1001
1002
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* >= C11 */
1003
# include <stdalign.h>
1004
# define XXH_ALIGN(n) alignas(n)
1005
#elif defined(__cplusplus) && (__cplusplus >= 201103L) /* >= C++11 */
1006
/* In C++ alignas() is a keyword */
1007
# define XXH_ALIGN(n) alignas(n)
1008
#elif defined(__GNUC__)
1009
# define XXH_ALIGN(n) __attribute__ ((aligned(n)))
1010
#elif defined(_MSC_VER)
1011
# define XXH_ALIGN(n) __declspec(align(n))
1012
#else
1013
# define XXH_ALIGN(n) /* disabled */
1014
#endif
1015
1016
/* Old GCC versions only accept the attribute after the type in structures. */
1017
#if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)) /* C11+ */ \
1018
&& ! (defined(__cplusplus) && (__cplusplus >= 201103L)) /* >= C++11 */ \
1019
&& defined(__GNUC__)
1020
# define XXH_ALIGN_MEMBER(align, type) type XXH_ALIGN(align)
1021
#else
1022
# define XXH_ALIGN_MEMBER(align, type) XXH_ALIGN(align) type
1023
#endif
1024
1025
/*!
1026
* @brief The size of the internal XXH3 buffer.
1027
*
1028
* This is the optimal update size for incremental hashing.
1029
*
1030
* @see XXH3_64b_update(), XXH3_128b_update().
1031
*/
1032
#define XXH3_INTERNALBUFFER_SIZE 256
1033
1034
/*!
1035
* @brief Default size of the secret buffer (and @ref XXH3_kSecret).
1036
*
1037
* This is the size used in @ref XXH3_kSecret and the seeded functions.
1038
*
1039
* Not to be confused with @ref XXH3_SECRET_SIZE_MIN.
1040
*/
1041
#define XXH3_SECRET_DEFAULT_SIZE 192
1042
1043
/*!
1044
* @internal
1045
* @brief Structure for XXH3 streaming API.
1046
*
1047
* @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
1048
* @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined.
1049
* Otherwise it is an opaque type.
1050
* Never use this definition in combination with dynamic library.
1051
* This allows fields to safely be changed in the future.
1052
*
1053
* @note ** This structure has a strict alignment requirement of 64 bytes!! **
1054
* Do not allocate this with `malloc()` or `new`,
1055
* it will not be sufficiently aligned.
1056
* Use @ref XXH3_createState() and @ref XXH3_freeState(), or stack allocation.
1057
*
1058
* Typedef'd to @ref XXH3_state_t.
1059
* Do never access the members of this struct directly.
1060
*
1061
* @see XXH3_INITSTATE() for stack initialization.
1062
* @see XXH3_createState(), XXH3_freeState().
1063
* @see XXH32_state_s, XXH64_state_s
1064
*/
1065
struct XXH3_state_s {
1066
XXH_ALIGN_MEMBER(64, XXH64_hash_t acc[8]);
1067
/*!< The 8 accumulators. Similar to `vN` in @ref XXH32_state_s::v1 and @ref XXH64_state_s */
1068
XXH_ALIGN_MEMBER(64, unsigned char customSecret[XXH3_SECRET_DEFAULT_SIZE]);
1069
/*!< Used to store a custom secret generated from a seed. */
1070
XXH_ALIGN_MEMBER(64, unsigned char buffer[XXH3_INTERNALBUFFER_SIZE]);
1071
/*!< The internal buffer. @see XXH32_state_s::mem32 */
1072
XXH32_hash_t bufferedSize;
1073
/*!< The amount of memory in @ref buffer, @see XXH32_state_s::memsize */
1074
XXH32_hash_t useSeed;
1075
/*!< Reserved field. Needed for padding on 64-bit. */
1076
size_t nbStripesSoFar;
1077
/*!< Number or stripes processed. */
1078
XXH64_hash_t totalLen;
1079
/*!< Total length hashed. 64-bit even on 32-bit targets. */
1080
size_t nbStripesPerBlock;
1081
/*!< Number of stripes per block. */
1082
size_t secretLimit;
1083
/*!< Size of @ref customSecret or @ref extSecret */
1084
XXH64_hash_t seed;
1085
/*!< Seed for _withSeed variants. Must be zero otherwise, @see XXH3_INITSTATE() */
1086
XXH64_hash_t reserved64;
1087
/*!< Reserved field. */
1088
const unsigned char* extSecret;
1089
/*!< Reference to an external secret for the _withSecret variants, NULL
1090
* for other variants. */
1091
/* note: there may be some padding at the end due to alignment on 64 bytes */
1092
}; /* typedef'd to XXH3_state_t */
1093
1094
#undef XXH_ALIGN_MEMBER
1095
1096
/*!
1097
* @brief Initializes a stack-allocated `XXH3_state_s`.
1098
*
1099
* When the @ref XXH3_state_t structure is merely emplaced on stack,
1100
* it should be initialized with XXH3_INITSTATE() or a memset()
1101
* in case its first reset uses XXH3_NNbits_reset_withSeed().
1102
* This init can be omitted if the first reset uses default or _withSecret mode.
1103
* This operation isn't necessary when the state is created with XXH3_createState().
1104
* Note that this doesn't prepare the state for a streaming operation,
1105
* it's still necessary to use XXH3_NNbits_reset*() afterwards.
1106
*/
1107
#define XXH3_INITSTATE(XXH3_state_ptr) { (XXH3_state_ptr)->seed = 0; }
1108
1109
1110
/* XXH128() :
1111
* simple alias to pre-selected XXH3_128bits variant
1112
*/
1113
XXH_PUBLIC_API XXH128_hash_t XXH128(const void* data, size_t len, XXH64_hash_t seed);
1114
1115
1116
/* === Experimental API === */
1117
/* Symbols defined below must be considered tied to a specific library version. */
1118
1119
/*
1120
* XXH3_generateSecret():
1121
*
1122
* Derive a high-entropy secret from any user-defined content, named customSeed.
1123
* The generated secret can be used in combination with `*_withSecret()` functions.
1124
* The `_withSecret()` variants are useful to provide a higher level of protection than 64-bit seed,
1125
* as it becomes much more difficult for an external actor to guess how to impact the calculation logic.
1126
*
1127
* The function accepts as input a custom seed of any length and any content,
1128
* and derives from it a high-entropy secret of length @secretSize
1129
* into an already allocated buffer @secretBuffer.
1130
* @secretSize must be >= XXH3_SECRET_SIZE_MIN
1131
*
1132
* The generated secret can then be used with any `*_withSecret()` variant.
1133
* Functions `XXH3_128bits_withSecret()`, `XXH3_64bits_withSecret()`,
1134
* `XXH3_128bits_reset_withSecret()` and `XXH3_64bits_reset_withSecret()`
1135
* are part of this list. They all accept a `secret` parameter
1136
* which must be large enough for implementation reasons (>= XXH3_SECRET_SIZE_MIN)
1137
* _and_ feature very high entropy (consist of random-looking bytes).
1138
* These conditions can be a high bar to meet, so
1139
* XXH3_generateSecret() can be employed to ensure proper quality.
1140
*
1141
* customSeed can be anything. It can have any size, even small ones,
1142
* and its content can be anything, even "poor entropy" sources such as a bunch of zeroes.
1143
* The resulting `secret` will nonetheless provide all required qualities.
1144
*
1145
* When customSeedSize > 0, supplying NULL as customSeed is undefined behavior.
1146
*/
1147
XXH_PUBLIC_API XXH_errorcode XXH3_generateSecret(void* secretBuffer, size_t secretSize, const void* customSeed, size_t customSeedSize);
1148
1149
1150
/*
1151
* XXH3_generateSecret_fromSeed():
1152
*
1153
* Generate the same secret as the _withSeed() variants.
1154
*
1155
* The resulting secret has a length of XXH3_SECRET_DEFAULT_SIZE (necessarily).
1156
* @secretBuffer must be already allocated, of size at least XXH3_SECRET_DEFAULT_SIZE bytes.
1157
*
1158
* The generated secret can be used in combination with
1159
*`*_withSecret()` and `_withSecretandSeed()` variants.
1160
* This generator is notably useful in combination with `_withSecretandSeed()`,
1161
* as a way to emulate a faster `_withSeed()` variant.
1162
*/
1163
XXH_PUBLIC_API void XXH3_generateSecret_fromSeed(void* secretBuffer, XXH64_hash_t seed);
1164
1165
/*
1166
* *_withSecretandSeed() :
1167
* These variants generate hash values using either
1168
* @seed for "short" keys (< XXH3_MIDSIZE_MAX = 240 bytes)
1169
* or @secret for "large" keys (>= XXH3_MIDSIZE_MAX).
1170
*
1171
* This generally benefits speed, compared to `_withSeed()` or `_withSecret()`.
1172
* `_withSeed()` has to generate the secret on the fly for "large" keys.
1173
* It's fast, but can be perceptible for "not so large" keys (< 1 KB).
1174
* `_withSecret()` has to generate the masks on the fly for "small" keys,
1175
* which requires more instructions than _withSeed() variants.
1176
* Therefore, _withSecretandSeed variant combines the best of both worlds.
1177
*
1178
* When @secret has been generated by XXH3_generateSecret_fromSeed(),
1179
* this variant produces *exactly* the same results as `_withSeed()` variant,
1180
* hence offering only a pure speed benefit on "large" input,
1181
* by skipping the need to regenerate the secret for every large input.
1182
*
1183
* Another usage scenario is to hash the secret to a 64-bit hash value,
1184
* for example with XXH3_64bits(), which then becomes the seed,
1185
* and then employ both the seed and the secret in _withSecretandSeed().
1186
* On top of speed, an added benefit is that each bit in the secret
1187
* has a 50% chance to swap each bit in the output,
1188
* via its impact to the seed.
1189
* This is not guaranteed when using the secret directly in "small data" scenarios,
1190
* because only portions of the secret are employed for small data.
1191
*/
1192
XXH_PUBLIC_API XXH64_hash_t
1193
XXH3_64bits_withSecretandSeed(const void* data, size_t len,
1194
const void* secret, size_t secretSize,
1195
XXH64_hash_t seed);
1196
1197
XXH_PUBLIC_API XXH128_hash_t
1198
XXH3_128bits_withSecretandSeed(const void* data, size_t len,
1199
const void* secret, size_t secretSize,
1200
XXH64_hash_t seed64);
1201
1202
XXH_PUBLIC_API XXH_errorcode
1203
XXH3_64bits_reset_withSecretandSeed(XXH3_state_t* statePtr,
1204
const void* secret, size_t secretSize,
1205
XXH64_hash_t seed64);
1206
1207
XXH_PUBLIC_API XXH_errorcode
1208
XXH3_128bits_reset_withSecretandSeed(XXH3_state_t* statePtr,
1209
const void* secret, size_t secretSize,
1210
XXH64_hash_t seed64);
1211
1212
1213
#endif /* XXH_NO_XXH3 */
1214
#endif /* XXH_NO_LONG_LONG */
1215
#if defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)
1216
# define XXH_IMPLEMENTATION
1217
#endif
1218
1219
#endif /* defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742) */
1220
1221
1222
/* ======================================================================== */
1223
/* ======================================================================== */
1224
/* ======================================================================== */
1225
1226
1227
/*-**********************************************************************
1228
* xxHash implementation
1229
*-**********************************************************************
1230
* xxHash's implementation used to be hosted inside xxhash.c.
1231
*
1232
* However, inlining requires implementation to be visible to the compiler,
1233
* hence be included alongside the header.
1234
* Previously, implementation was hosted inside xxhash.c,
1235
* which was then #included when inlining was activated.
1236
* This construction created issues with a few build and install systems,
1237
* as it required xxhash.c to be stored in /include directory.
1238
*
1239
* xxHash implementation is now directly integrated within xxhash.h.
1240
* As a consequence, xxhash.c is no longer needed in /include.
1241
*
1242
* xxhash.c is still available and is still useful.
1243
* In a "normal" setup, when xxhash is not inlined,
1244
* xxhash.h only exposes the prototypes and public symbols,
1245
* while xxhash.c can be built into an object file xxhash.o
1246
* which can then be linked into the final binary.
1247
************************************************************************/
1248
1249
#if ( defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API) \
1250
|| defined(XXH_IMPLEMENTATION) ) && !defined(XXH_IMPLEM_13a8737387)
1251
# define XXH_IMPLEM_13a8737387
1252
1253
/* *************************************
1254
* Tuning parameters
1255
***************************************/
1256
1257
/*!
1258
* @defgroup tuning Tuning parameters
1259
* @{
1260
*
1261
* Various macros to control xxHash's behavior.
1262
*/
1263
#ifdef XXH_DOXYGEN
1264
/*!
1265
* @brief Define this to disable 64-bit code.
1266
*
1267
* Useful if only using the @ref xxh32_family and you have a strict C90 compiler.
1268
*/
1269
# define XXH_NO_LONG_LONG
1270
# undef XXH_NO_LONG_LONG /* don't actually */
1271
/*!
1272
* @brief Controls how unaligned memory is accessed.
1273
*
1274
* By default, access to unaligned memory is controlled by `memcpy()`, which is
1275
* safe and portable.
1276
*
1277
* Unfortunately, on some target/compiler combinations, the generated assembly
1278
* is sub-optimal.
1279
*
1280
* The below switch allow selection of a different access method
1281
* in the search for improved performance.
1282
*
1283
* @par Possible options:
1284
*
1285
* - `XXH_FORCE_MEMORY_ACCESS=0` (default): `memcpy`
1286
* @par
1287
* Use `memcpy()`. Safe and portable. Note that most modern compilers will
1288
* eliminate the function call and treat it as an unaligned access.
1289
*
1290
* - `XXH_FORCE_MEMORY_ACCESS=1`: `__attribute__((packed))`
1291
* @par
1292
* Depends on compiler extensions and is therefore not portable.
1293
* This method is safe _if_ your compiler supports it,
1294
* and *generally* as fast or faster than `memcpy`.
1295
*
1296
* - `XXH_FORCE_MEMORY_ACCESS=2`: Direct cast
1297
* @par
1298
* Casts directly and dereferences. This method doesn't depend on the
1299
* compiler, but it violates the C standard as it directly dereferences an
1300
* unaligned pointer. It can generate buggy code on targets which do not
1301
* support unaligned memory accesses, but in some circumstances, it's the
1302
* only known way to get the most performance.
1303
*
1304
* - `XXH_FORCE_MEMORY_ACCESS=3`: Byteshift
1305
* @par
1306
* Also portable. This can generate the best code on old compilers which don't
1307
* inline small `memcpy()` calls, and it might also be faster on big-endian
1308
* systems which lack a native byteswap instruction. However, some compilers
1309
* will emit literal byteshifts even if the target supports unaligned access.
1310
* .
1311
*
1312
* @warning
1313
* Methods 1 and 2 rely on implementation-defined behavior. Use these with
1314
* care, as what works on one compiler/platform/optimization level may cause
1315
* another to read garbage data or even crash.
1316
*
1317
* See https://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html for details.
1318
*
1319
* Prefer these methods in priority order (0 > 3 > 1 > 2)
1320
*/
1321
# define XXH_FORCE_MEMORY_ACCESS 0
1322
1323
/*!
1324
* @def XXH_FORCE_ALIGN_CHECK
1325
* @brief If defined to non-zero, adds a special path for aligned inputs (XXH32()
1326
* and XXH64() only).
1327
*
1328
* This is an important performance trick for architectures without decent
1329
* unaligned memory access performance.
1330
*
1331
* It checks for input alignment, and when conditions are met, uses a "fast
1332
* path" employing direct 32-bit/64-bit reads, resulting in _dramatically
1333
* faster_ read speed.
1334
*
1335
* The check costs one initial branch per hash, which is generally negligible,
1336
* but not zero.
1337
*
1338
* Moreover, it's not useful to generate an additional code path if memory
1339
* access uses the same instruction for both aligned and unaligned
1340
* addresses (e.g. x86 and aarch64).
1341
*
1342
* In these cases, the alignment check can be removed by setting this macro to 0.
1343
* Then the code will always use unaligned memory access.
1344
* Align check is automatically disabled on x86, x64 & arm64,
1345
* which are platforms known to offer good unaligned memory accesses performance.
1346
*
1347
* This option does not affect XXH3 (only XXH32 and XXH64).
1348
*/
1349
# define XXH_FORCE_ALIGN_CHECK 0
1350
1351
/*!
1352
* @def XXH_NO_INLINE_HINTS
1353
* @brief When non-zero, sets all functions to `static`.
1354
*
1355
* By default, xxHash tries to force the compiler to inline almost all internal
1356
* functions.
1357
*
1358
* This can usually improve performance due to reduced jumping and improved
1359
* constant folding, but significantly increases the size of the binary which
1360
* might not be favorable.
1361
*
1362
* Additionally, sometimes the forced inlining can be detrimental to performance,
1363
* depending on the architecture.
1364
*
1365
* XXH_NO_INLINE_HINTS marks all internal functions as static, giving the
1366
* compiler full control on whether to inline or not.
1367
*
1368
* When not optimizing (-O0), optimizing for size (-Os, -Oz), or using
1369
* -fno-inline with GCC or Clang, this will automatically be defined.
1370
*/
1371
# define XXH_NO_INLINE_HINTS 0
1372
1373
/*!
1374
* @def XXH32_ENDJMP
1375
* @brief Whether to use a jump for `XXH32_finalize`.
1376
*
1377
* For performance, `XXH32_finalize` uses multiple branches in the finalizer.
1378
* This is generally preferable for performance,
1379
* but depending on exact architecture, a jmp may be preferable.
1380
*
1381
* This setting is only possibly making a difference for very small inputs.
1382
*/
1383
# define XXH32_ENDJMP 0
1384
1385
/*!
1386
* @internal
1387
* @brief Redefines old internal names.
1388
*
1389
* For compatibility with code that uses xxHash's internals before the names
1390
* were changed to improve namespacing. There is no other reason to use this.
1391
*/
1392
# define XXH_OLD_NAMES
1393
# undef XXH_OLD_NAMES /* don't actually use, it is ugly. */
1394
#endif /* XXH_DOXYGEN */
1395
/*!
1396
* @}
1397
*/
1398
1399
#ifndef XXH_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */
1400
/* prefer __packed__ structures (method 1) for gcc on armv7+ and mips */
1401
# if !defined(__clang__) && \
1402
( \
1403
(defined(__INTEL_COMPILER) && !defined(_WIN32)) || \
1404
( \
1405
defined(__GNUC__) && ( \
1406
(defined(__ARM_ARCH) && __ARM_ARCH >= 7) || \
1407
( \
1408
defined(__mips__) && \
1409
(__mips <= 5 || __mips_isa_rev < 6) && \
1410
(!defined(__mips16) || defined(__mips_mips16e2)) \
1411
) \
1412
) \
1413
) \
1414
)
1415
# define XXH_FORCE_MEMORY_ACCESS 1
1416
# endif
1417
#endif
1418
1419
#ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
1420
# if defined(__i386) || defined(__x86_64__) || defined(__aarch64__) \
1421
|| defined(_M_IX86) || defined(_M_X64) || defined(_M_ARM64) /* visual */
1422
# define XXH_FORCE_ALIGN_CHECK 0
1423
# else
1424
# define XXH_FORCE_ALIGN_CHECK 1
1425
# endif
1426
#endif
1427
1428
#ifndef XXH_NO_INLINE_HINTS
1429
# if defined(__OPTIMIZE_SIZE__) /* -Os, -Oz */ \
1430
|| defined(__NO_INLINE__) /* -O0, -fno-inline */
1431
# define XXH_NO_INLINE_HINTS 1
1432
# else
1433
# define XXH_NO_INLINE_HINTS 0
1434
# endif
1435
#endif
1436
1437
#ifndef XXH32_ENDJMP
1438
/* generally preferable for performance */
1439
# define XXH32_ENDJMP 0
1440
#endif
1441
1442
/*!
1443
* @defgroup impl Implementation
1444
* @{
1445
*/
1446
1447
1448
/* *************************************
1449
* Includes & Memory related functions
1450
***************************************/
1451
/* Modify the local functions below should you wish to use some other memory routines */
1452
/* for ZSTD_malloc(), ZSTD_free() */
1453
#define ZSTD_DEPS_NEED_MALLOC
1454
#include "zstd_deps.h" /* size_t, ZSTD_malloc, ZSTD_free, ZSTD_memcpy */
1455
static void* XXH_malloc(size_t s) { return ZSTD_malloc(s); }
1456
static void XXH_free (void* p) { ZSTD_free(p); }
1457
static void* XXH_memcpy(void* dest, const void* src, size_t size) { return ZSTD_memcpy(dest,src,size); }
1458
1459
1460
/* *************************************
1461
* Compiler Specific Options
1462
***************************************/
1463
#ifdef _MSC_VER /* Visual Studio warning fix */
1464
# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
1465
#endif
1466
1467
#if XXH_NO_INLINE_HINTS /* disable inlining hints */
1468
# if defined(__GNUC__) || defined(__clang__)
1469
# define XXH_FORCE_INLINE static __attribute__((unused))
1470
# else
1471
# define XXH_FORCE_INLINE static
1472
# endif
1473
# define XXH_NO_INLINE static
1474
/* enable inlining hints */
1475
#elif defined(__GNUC__) || defined(__clang__)
1476
# define XXH_FORCE_INLINE static __inline__ __attribute__((always_inline, unused))
1477
# define XXH_NO_INLINE static __attribute__((noinline))
1478
#elif defined(_MSC_VER) /* Visual Studio */
1479
# define XXH_FORCE_INLINE static __forceinline
1480
# define XXH_NO_INLINE static __declspec(noinline)
1481
#elif defined (__cplusplus) \
1482
|| (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) /* C99 */
1483
# define XXH_FORCE_INLINE static inline
1484
# define XXH_NO_INLINE static
1485
#else
1486
# define XXH_FORCE_INLINE static
1487
# define XXH_NO_INLINE static
1488
#endif
1489
1490
1491
1492
/* *************************************
1493
* Debug
1494
***************************************/
1495
/*!
1496
* @ingroup tuning
1497
* @def XXH_DEBUGLEVEL
1498
* @brief Sets the debugging level.
1499
*
1500
* XXH_DEBUGLEVEL is expected to be defined externally, typically via the
1501
* compiler's command line options. The value must be a number.
1502
*/
1503
#ifndef XXH_DEBUGLEVEL
1504
# ifdef DEBUGLEVEL /* backwards compat */
1505
# define XXH_DEBUGLEVEL DEBUGLEVEL
1506
# else
1507
# define XXH_DEBUGLEVEL 0
1508
# endif
1509
#endif
1510
1511
#if (XXH_DEBUGLEVEL>=1)
1512
# include <assert.h> /* note: can still be disabled with NDEBUG */
1513
# define XXH_ASSERT(c) assert(c)
1514
#else
1515
# define XXH_ASSERT(c) ((void)0)
1516
#endif
1517
1518
/* note: use after variable declarations */
1519
#ifndef XXH_STATIC_ASSERT
1520
# if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* C11 */
1521
# include <assert.h>
1522
# define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { static_assert((c),m); } while(0)
1523
# elif defined(__cplusplus) && (__cplusplus >= 201103L) /* C++11 */
1524
# define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { static_assert((c),m); } while(0)
1525
# else
1526
# define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { struct xxh_sa { char x[(c) ? 1 : -1]; }; } while(0)
1527
# endif
1528
# define XXH_STATIC_ASSERT(c) XXH_STATIC_ASSERT_WITH_MESSAGE((c),#c)
1529
#endif
1530
1531
/*!
1532
* @internal
1533
* @def XXH_COMPILER_GUARD(var)
1534
* @brief Used to prevent unwanted optimizations for @p var.
1535
*
1536
* It uses an empty GCC inline assembly statement with a register constraint
1537
* which forces @p var into a general purpose register (e.g. eax, ebx, ecx
1538
* on x86) and marks it as modified.
1539
*
1540
* This is used in a few places to avoid unwanted autovectorization (e.g.
1541
* XXH32_round()). All vectorization we want is explicit via intrinsics,
1542
* and _usually_ isn't wanted elsewhere.
1543
*
1544
* We also use it to prevent unwanted constant folding for AArch64 in
1545
* XXH3_initCustomSecret_scalar().
1546
*/
1547
#if defined(__GNUC__) || defined(__clang__)
1548
# define XXH_COMPILER_GUARD(var) __asm__ __volatile__("" : "+r" (var))
1549
#else
1550
# define XXH_COMPILER_GUARD(var) ((void)0)
1551
#endif
1552
1553
/* *************************************
1554
* Basic Types
1555
***************************************/
1556
#if !defined (__VMS) \
1557
&& (defined (__cplusplus) \
1558
|| (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
1559
# include <stdint.h>
1560
typedef uint8_t xxh_u8;
1561
#else
1562
typedef unsigned char xxh_u8;
1563
#endif
1564
typedef XXH32_hash_t xxh_u32;
1565
1566
#ifdef XXH_OLD_NAMES
1567
# define BYTE xxh_u8
1568
# define U8 xxh_u8
1569
# define U32 xxh_u32
1570
#endif
1571
1572
/* *** Memory access *** */
1573
1574
/*!
1575
* @internal
1576
* @fn xxh_u32 XXH_read32(const void* ptr)
1577
* @brief Reads an unaligned 32-bit integer from @p ptr in native endianness.
1578
*
1579
* Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1580
*
1581
* @param ptr The pointer to read from.
1582
* @return The 32-bit native endian integer from the bytes at @p ptr.
1583
*/
1584
1585
/*!
1586
* @internal
1587
* @fn xxh_u32 XXH_readLE32(const void* ptr)
1588
* @brief Reads an unaligned 32-bit little endian integer from @p ptr.
1589
*
1590
* Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1591
*
1592
* @param ptr The pointer to read from.
1593
* @return The 32-bit little endian integer from the bytes at @p ptr.
1594
*/
1595
1596
/*!
1597
* @internal
1598
* @fn xxh_u32 XXH_readBE32(const void* ptr)
1599
* @brief Reads an unaligned 32-bit big endian integer from @p ptr.
1600
*
1601
* Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1602
*
1603
* @param ptr The pointer to read from.
1604
* @return The 32-bit big endian integer from the bytes at @p ptr.
1605
*/
1606
1607
/*!
1608
* @internal
1609
* @fn xxh_u32 XXH_readLE32_align(const void* ptr, XXH_alignment align)
1610
* @brief Like @ref XXH_readLE32(), but has an option for aligned reads.
1611
*
1612
* Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1613
* Note that when @ref XXH_FORCE_ALIGN_CHECK == 0, the @p align parameter is
1614
* always @ref XXH_alignment::XXH_unaligned.
1615
*
1616
* @param ptr The pointer to read from.
1617
* @param align Whether @p ptr is aligned.
1618
* @pre
1619
* If @p align == @ref XXH_alignment::XXH_aligned, @p ptr must be 4 byte
1620
* aligned.
1621
* @return The 32-bit little endian integer from the bytes at @p ptr.
1622
*/
1623
1624
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
1625
/*
1626
* Manual byteshift. Best for old compilers which don't inline memcpy.
1627
* We actually directly use XXH_readLE32 and XXH_readBE32.
1628
*/
1629
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
1630
1631
/*
1632
* Force direct memory access. Only works on CPU which support unaligned memory
1633
* access in hardware.
1634
*/
1635
static xxh_u32 XXH_read32(const void* memPtr) { return *(const xxh_u32*) memPtr; }
1636
1637
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
1638
1639
/*
1640
* __pack instructions are safer but compiler specific, hence potentially
1641
* problematic for some compilers.
1642
*
1643
* Currently only defined for GCC and ICC.
1644
*/
1645
#ifdef XXH_OLD_NAMES
1646
typedef union { xxh_u32 u32; } __attribute__((packed)) unalign;
1647
#endif
1648
static xxh_u32 XXH_read32(const void* ptr)
1649
{
1650
typedef union { xxh_u32 u32; } __attribute__((packed)) xxh_unalign;
1651
return ((const xxh_unalign*)ptr)->u32;
1652
}
1653
1654
#else
1655
1656
/*
1657
* Portable and safe solution. Generally efficient.
1658
* see: https://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html
1659
*/
1660
static xxh_u32 XXH_read32(const void* memPtr)
1661
{
1662
xxh_u32 val;
1663
XXH_memcpy(&val, memPtr, sizeof(val));
1664
return val;
1665
}
1666
1667
#endif /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
1668
1669
1670
/* *** Endianness *** */
1671
1672
/*!
1673
* @ingroup tuning
1674
* @def XXH_CPU_LITTLE_ENDIAN
1675
* @brief Whether the target is little endian.
1676
*
1677
* Defined to 1 if the target is little endian, or 0 if it is big endian.
1678
* It can be defined externally, for example on the compiler command line.
1679
*
1680
* If it is not defined,
1681
* a runtime check (which is usually constant folded) is used instead.
1682
*
1683
* @note
1684
* This is not necessarily defined to an integer constant.
1685
*
1686
* @see XXH_isLittleEndian() for the runtime check.
1687
*/
1688
#ifndef XXH_CPU_LITTLE_ENDIAN
1689
/*
1690
* Try to detect endianness automatically, to avoid the nonstandard behavior
1691
* in `XXH_isLittleEndian()`
1692
*/
1693
# if defined(_WIN32) /* Windows is always little endian */ \
1694
|| defined(__LITTLE_ENDIAN__) \
1695
|| (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
1696
# define XXH_CPU_LITTLE_ENDIAN 1
1697
# elif defined(__BIG_ENDIAN__) \
1698
|| (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
1699
# define XXH_CPU_LITTLE_ENDIAN 0
1700
# else
1701
/*!
1702
* @internal
1703
* @brief Runtime check for @ref XXH_CPU_LITTLE_ENDIAN.
1704
*
1705
* Most compilers will constant fold this.
1706
*/
1707
static int XXH_isLittleEndian(void)
1708
{
1709
/*
1710
* Portable and well-defined behavior.
1711
* Don't use static: it is detrimental to performance.
1712
*/
1713
const union { xxh_u32 u; xxh_u8 c[4]; } one = { 1 };
1714
return one.c[0];
1715
}
1716
# define XXH_CPU_LITTLE_ENDIAN XXH_isLittleEndian()
1717
# endif
1718
#endif
1719
1720
1721
1722
1723
/* ****************************************
1724
* Compiler-specific Functions and Macros
1725
******************************************/
1726
#define XXH_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
1727
1728
#ifdef __has_builtin
1729
# define XXH_HAS_BUILTIN(x) __has_builtin(x)
1730
#else
1731
# define XXH_HAS_BUILTIN(x) 0
1732
#endif
1733
1734
/*!
1735
* @internal
1736
* @def XXH_rotl32(x,r)
1737
* @brief 32-bit rotate left.
1738
*
1739
* @param x The 32-bit integer to be rotated.
1740
* @param r The number of bits to rotate.
1741
* @pre
1742
* @p r > 0 && @p r < 32
1743
* @note
1744
* @p x and @p r may be evaluated multiple times.
1745
* @return The rotated result.
1746
*/
1747
#if !defined(NO_CLANG_BUILTIN) && XXH_HAS_BUILTIN(__builtin_rotateleft32) \
1748
&& XXH_HAS_BUILTIN(__builtin_rotateleft64)
1749
# define XXH_rotl32 __builtin_rotateleft32
1750
# define XXH_rotl64 __builtin_rotateleft64
1751
/* Note: although _rotl exists for minGW (GCC under windows), performance seems poor */
1752
#elif defined(_MSC_VER)
1753
# define XXH_rotl32(x,r) _rotl(x,r)
1754
# define XXH_rotl64(x,r) _rotl64(x,r)
1755
#else
1756
# define XXH_rotl32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
1757
# define XXH_rotl64(x,r) (((x) << (r)) | ((x) >> (64 - (r))))
1758
#endif
1759
1760
/*!
1761
* @internal
1762
* @fn xxh_u32 XXH_swap32(xxh_u32 x)
1763
* @brief A 32-bit byteswap.
1764
*
1765
* @param x The 32-bit integer to byteswap.
1766
* @return @p x, byteswapped.
1767
*/
1768
#if defined(_MSC_VER) /* Visual Studio */
1769
# define XXH_swap32 _byteswap_ulong
1770
#elif XXH_GCC_VERSION >= 403
1771
# define XXH_swap32 __builtin_bswap32
1772
#else
1773
static xxh_u32 XXH_swap32 (xxh_u32 x)
1774
{
1775
return ((x << 24) & 0xff000000 ) |
1776
((x << 8) & 0x00ff0000 ) |
1777
((x >> 8) & 0x0000ff00 ) |
1778
((x >> 24) & 0x000000ff );
1779
}
1780
#endif
1781
1782
1783
/* ***************************
1784
* Memory reads
1785
*****************************/
1786
1787
/*!
1788
* @internal
1789
* @brief Enum to indicate whether a pointer is aligned.
1790
*/
1791
typedef enum {
1792
XXH_aligned, /*!< Aligned */
1793
XXH_unaligned /*!< Possibly unaligned */
1794
} XXH_alignment;
1795
1796
/*
1797
* XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load.
1798
*
1799
* This is ideal for older compilers which don't inline memcpy.
1800
*/
1801
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
1802
1803
XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* memPtr)
1804
{
1805
const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
1806
return bytePtr[0]
1807
| ((xxh_u32)bytePtr[1] << 8)
1808
| ((xxh_u32)bytePtr[2] << 16)
1809
| ((xxh_u32)bytePtr[3] << 24);
1810
}
1811
1812
XXH_FORCE_INLINE xxh_u32 XXH_readBE32(const void* memPtr)
1813
{
1814
const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
1815
return bytePtr[3]
1816
| ((xxh_u32)bytePtr[2] << 8)
1817
| ((xxh_u32)bytePtr[1] << 16)
1818
| ((xxh_u32)bytePtr[0] << 24);
1819
}
1820
1821
#else
1822
XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* ptr)
1823
{
1824
return XXH_CPU_LITTLE_ENDIAN ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
1825
}
1826
1827
static xxh_u32 XXH_readBE32(const void* ptr)
1828
{
1829
return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
1830
}
1831
#endif
1832
1833
XXH_FORCE_INLINE xxh_u32
1834
XXH_readLE32_align(const void* ptr, XXH_alignment align)
1835
{
1836
if (align==XXH_unaligned) {
1837
return XXH_readLE32(ptr);
1838
} else {
1839
return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u32*)ptr : XXH_swap32(*(const xxh_u32*)ptr);
1840
}
1841
}
1842
1843
1844
/* *************************************
1845
* Misc
1846
***************************************/
1847
/*! @ingroup public */
1848
XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
1849
1850
1851
/* *******************************************************************
1852
* 32-bit hash functions
1853
*********************************************************************/
1854
/*!
1855
* @}
1856
* @defgroup xxh32_impl XXH32 implementation
1857
* @ingroup impl
1858
* @{
1859
*/
1860
/* #define instead of static const, to be used as initializers */
1861
#define XXH_PRIME32_1 0x9E3779B1U /*!< 0b10011110001101110111100110110001 */
1862
#define XXH_PRIME32_2 0x85EBCA77U /*!< 0b10000101111010111100101001110111 */
1863
#define XXH_PRIME32_3 0xC2B2AE3DU /*!< 0b11000010101100101010111000111101 */
1864
#define XXH_PRIME32_4 0x27D4EB2FU /*!< 0b00100111110101001110101100101111 */
1865
#define XXH_PRIME32_5 0x165667B1U /*!< 0b00010110010101100110011110110001 */
1866
1867
#ifdef XXH_OLD_NAMES
1868
# define PRIME32_1 XXH_PRIME32_1
1869
# define PRIME32_2 XXH_PRIME32_2
1870
# define PRIME32_3 XXH_PRIME32_3
1871
# define PRIME32_4 XXH_PRIME32_4
1872
# define PRIME32_5 XXH_PRIME32_5
1873
#endif
1874
1875
/*!
1876
* @internal
1877
* @brief Normal stripe processing routine.
1878
*
1879
* This shuffles the bits so that any bit from @p input impacts several bits in
1880
* @p acc.
1881
*
1882
* @param acc The accumulator lane.
1883
* @param input The stripe of input to mix.
1884
* @return The mixed accumulator lane.
1885
*/
1886
static xxh_u32 XXH32_round(xxh_u32 acc, xxh_u32 input)
1887
{
1888
acc += input * XXH_PRIME32_2;
1889
acc = XXH_rotl32(acc, 13);
1890
acc *= XXH_PRIME32_1;
1891
#if (defined(__SSE4_1__) || defined(__aarch64__)) && !defined(XXH_ENABLE_AUTOVECTORIZE)
1892
/*
1893
* UGLY HACK:
1894
* A compiler fence is the only thing that prevents GCC and Clang from
1895
* autovectorizing the XXH32 loop (pragmas and attributes don't work for some
1896
* reason) without globally disabling SSE4.1.
1897
*
1898
* The reason we want to avoid vectorization is because despite working on
1899
* 4 integers at a time, there are multiple factors slowing XXH32 down on
1900
* SSE4:
1901
* - There's a ridiculous amount of lag from pmulld (10 cycles of latency on
1902
* newer chips!) making it slightly slower to multiply four integers at
1903
* once compared to four integers independently. Even when pmulld was
1904
* fastest, Sandy/Ivy Bridge, it is still not worth it to go into SSE
1905
* just to multiply unless doing a long operation.
1906
*
1907
* - Four instructions are required to rotate,
1908
* movqda tmp, v // not required with VEX encoding
1909
* pslld tmp, 13 // tmp <<= 13
1910
* psrld v, 19 // x >>= 19
1911
* por v, tmp // x |= tmp
1912
* compared to one for scalar:
1913
* roll v, 13 // reliably fast across the board
1914
* shldl v, v, 13 // Sandy Bridge and later prefer this for some reason
1915
*
1916
* - Instruction level parallelism is actually more beneficial here because
1917
* the SIMD actually serializes this operation: While v1 is rotating, v2
1918
* can load data, while v3 can multiply. SSE forces them to operate
1919
* together.
1920
*
1921
* This is also enabled on AArch64, as Clang autovectorizes it incorrectly
1922
* and it is pointless writing a NEON implementation that is basically the
1923
* same speed as scalar for XXH32.
1924
*/
1925
XXH_COMPILER_GUARD(acc);
1926
#endif
1927
return acc;
1928
}
1929
1930
/*!
1931
* @internal
1932
* @brief Mixes all bits to finalize the hash.
1933
*
1934
* The final mix ensures that all input bits have a chance to impact any bit in
1935
* the output digest, resulting in an unbiased distribution.
1936
*
1937
* @param h32 The hash to avalanche.
1938
* @return The avalanched hash.
1939
*/
1940
static xxh_u32 XXH32_avalanche(xxh_u32 h32)
1941
{
1942
h32 ^= h32 >> 15;
1943
h32 *= XXH_PRIME32_2;
1944
h32 ^= h32 >> 13;
1945
h32 *= XXH_PRIME32_3;
1946
h32 ^= h32 >> 16;
1947
return(h32);
1948
}
1949
1950
#define XXH_get32bits(p) XXH_readLE32_align(p, align)
1951
1952
/*!
1953
* @internal
1954
* @brief Processes the last 0-15 bytes of @p ptr.
1955
*
1956
* There may be up to 15 bytes remaining to consume from the input.
1957
* This final stage will digest them to ensure that all input bytes are present
1958
* in the final mix.
1959
*
1960
* @param h32 The hash to finalize.
1961
* @param ptr The pointer to the remaining input.
1962
* @param len The remaining length, modulo 16.
1963
* @param align Whether @p ptr is aligned.
1964
* @return The finalized hash.
1965
*/
1966
static xxh_u32
1967
XXH32_finalize(xxh_u32 h32, const xxh_u8* ptr, size_t len, XXH_alignment align)
1968
{
1969
#define XXH_PROCESS1 do { \
1970
h32 += (*ptr++) * XXH_PRIME32_5; \
1971
h32 = XXH_rotl32(h32, 11) * XXH_PRIME32_1; \
1972
} while (0)
1973
1974
#define XXH_PROCESS4 do { \
1975
h32 += XXH_get32bits(ptr) * XXH_PRIME32_3; \
1976
ptr += 4; \
1977
h32 = XXH_rotl32(h32, 17) * XXH_PRIME32_4; \
1978
} while (0)
1979
1980
if (ptr==NULL) XXH_ASSERT(len == 0);
1981
1982
/* Compact rerolled version; generally faster */
1983
if (!XXH32_ENDJMP) {
1984
len &= 15;
1985
while (len >= 4) {
1986
XXH_PROCESS4;
1987
len -= 4;
1988
}
1989
while (len > 0) {
1990
XXH_PROCESS1;
1991
--len;
1992
}
1993
return XXH32_avalanche(h32);
1994
} else {
1995
switch(len&15) /* or switch(bEnd - p) */ {
1996
case 12: XXH_PROCESS4;
1997
XXH_FALLTHROUGH;
1998
case 8: XXH_PROCESS4;
1999
XXH_FALLTHROUGH;
2000
case 4: XXH_PROCESS4;
2001
return XXH32_avalanche(h32);
2002
2003
case 13: XXH_PROCESS4;
2004
XXH_FALLTHROUGH;
2005
case 9: XXH_PROCESS4;
2006
XXH_FALLTHROUGH;
2007
case 5: XXH_PROCESS4;
2008
XXH_PROCESS1;
2009
return XXH32_avalanche(h32);
2010
2011
case 14: XXH_PROCESS4;
2012
XXH_FALLTHROUGH;
2013
case 10: XXH_PROCESS4;
2014
XXH_FALLTHROUGH;
2015
case 6: XXH_PROCESS4;
2016
XXH_PROCESS1;
2017
XXH_PROCESS1;
2018
return XXH32_avalanche(h32);
2019
2020
case 15: XXH_PROCESS4;
2021
XXH_FALLTHROUGH;
2022
case 11: XXH_PROCESS4;
2023
XXH_FALLTHROUGH;
2024
case 7: XXH_PROCESS4;
2025
XXH_FALLTHROUGH;
2026
case 3: XXH_PROCESS1;
2027
XXH_FALLTHROUGH;
2028
case 2: XXH_PROCESS1;
2029
XXH_FALLTHROUGH;
2030
case 1: XXH_PROCESS1;
2031
XXH_FALLTHROUGH;
2032
case 0: return XXH32_avalanche(h32);
2033
}
2034
XXH_ASSERT(0);
2035
return h32; /* reaching this point is deemed impossible */
2036
}
2037
}
2038
2039
#ifdef XXH_OLD_NAMES
2040
# define PROCESS1 XXH_PROCESS1
2041
# define PROCESS4 XXH_PROCESS4
2042
#else
2043
# undef XXH_PROCESS1
2044
# undef XXH_PROCESS4
2045
#endif
2046
2047
/*!
2048
* @internal
2049
* @brief The implementation for @ref XXH32().
2050
*
2051
* @param input , len , seed Directly passed from @ref XXH32().
2052
* @param align Whether @p input is aligned.
2053
* @return The calculated hash.
2054
*/
2055
XXH_FORCE_INLINE xxh_u32
2056
XXH32_endian_align(const xxh_u8* input, size_t len, xxh_u32 seed, XXH_alignment align)
2057
{
2058
xxh_u32 h32;
2059
2060
if (input==NULL) XXH_ASSERT(len == 0);
2061
2062
if (len>=16) {
2063
const xxh_u8* const bEnd = input + len;
2064
const xxh_u8* const limit = bEnd - 15;
2065
xxh_u32 v1 = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
2066
xxh_u32 v2 = seed + XXH_PRIME32_2;
2067
xxh_u32 v3 = seed + 0;
2068
xxh_u32 v4 = seed - XXH_PRIME32_1;
2069
2070
do {
2071
v1 = XXH32_round(v1, XXH_get32bits(input)); input += 4;
2072
v2 = XXH32_round(v2, XXH_get32bits(input)); input += 4;
2073
v3 = XXH32_round(v3, XXH_get32bits(input)); input += 4;
2074
v4 = XXH32_round(v4, XXH_get32bits(input)); input += 4;
2075
} while (input < limit);
2076
2077
h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7)
2078
+ XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
2079
} else {
2080
h32 = seed + XXH_PRIME32_5;
2081
}
2082
2083
h32 += (xxh_u32)len;
2084
2085
return XXH32_finalize(h32, input, len&15, align);
2086
}
2087
2088
/*! @ingroup xxh32_family */
2089
XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t len, XXH32_hash_t seed)
2090
{
2091
#if 0
2092
/* Simple version, good for code maintenance, but unfortunately slow for small inputs */
2093
XXH32_state_t state;
2094
XXH32_reset(&state, seed);
2095
XXH32_update(&state, (const xxh_u8*)input, len);
2096
return XXH32_digest(&state);
2097
#else
2098
if (XXH_FORCE_ALIGN_CHECK) {
2099
if ((((size_t)input) & 3) == 0) { /* Input is 4-bytes aligned, leverage the speed benefit */
2100
return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
2101
} }
2102
2103
return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);
2104
#endif
2105
}
2106
2107
2108
2109
/******* Hash streaming *******/
2110
/*!
2111
* @ingroup xxh32_family
2112
*/
2113
XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
2114
{
2115
return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
2116
}
2117
/*! @ingroup xxh32_family */
2118
XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
2119
{
2120
XXH_free(statePtr);
2121
return XXH_OK;
2122
}
2123
2124
/*! @ingroup xxh32_family */
2125
XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dstState, const XXH32_state_t* srcState)
2126
{
2127
XXH_memcpy(dstState, srcState, sizeof(*dstState));
2128
}
2129
2130
/*! @ingroup xxh32_family */
2131
XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, XXH32_hash_t seed)
2132
{
2133
XXH_ASSERT(statePtr != NULL);
2134
memset(statePtr, 0, sizeof(*statePtr));
2135
statePtr->v[0] = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
2136
statePtr->v[1] = seed + XXH_PRIME32_2;
2137
statePtr->v[2] = seed + 0;
2138
statePtr->v[3] = seed - XXH_PRIME32_1;
2139
return XXH_OK;
2140
}
2141
2142
2143
/*! @ingroup xxh32_family */
2144
XXH_PUBLIC_API XXH_errorcode
2145
XXH32_update(XXH32_state_t* state, const void* input, size_t len)
2146
{
2147
if (input==NULL) {
2148
XXH_ASSERT(len == 0);
2149
return XXH_OK;
2150
}
2151
2152
{ const xxh_u8* p = (const xxh_u8*)input;
2153
const xxh_u8* const bEnd = p + len;
2154
2155
state->total_len_32 += (XXH32_hash_t)len;
2156
state->large_len |= (XXH32_hash_t)((len>=16) | (state->total_len_32>=16));
2157
2158
if (state->memsize + len < 16) { /* fill in tmp buffer */
2159
XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, len);
2160
state->memsize += (XXH32_hash_t)len;
2161
return XXH_OK;
2162
}
2163
2164
if (state->memsize) { /* some data left from previous update */
2165
XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, 16-state->memsize);
2166
{ const xxh_u32* p32 = state->mem32;
2167
state->v[0] = XXH32_round(state->v[0], XXH_readLE32(p32)); p32++;
2168
state->v[1] = XXH32_round(state->v[1], XXH_readLE32(p32)); p32++;
2169
state->v[2] = XXH32_round(state->v[2], XXH_readLE32(p32)); p32++;
2170
state->v[3] = XXH32_round(state->v[3], XXH_readLE32(p32));
2171
}
2172
p += 16-state->memsize;
2173
state->memsize = 0;
2174
}
2175
2176
if (p <= bEnd-16) {
2177
const xxh_u8* const limit = bEnd - 16;
2178
2179
do {
2180
state->v[0] = XXH32_round(state->v[0], XXH_readLE32(p)); p+=4;
2181
state->v[1] = XXH32_round(state->v[1], XXH_readLE32(p)); p+=4;
2182
state->v[2] = XXH32_round(state->v[2], XXH_readLE32(p)); p+=4;
2183
state->v[3] = XXH32_round(state->v[3], XXH_readLE32(p)); p+=4;
2184
} while (p<=limit);
2185
2186
}
2187
2188
if (p < bEnd) {
2189
XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
2190
state->memsize = (unsigned)(bEnd-p);
2191
}
2192
}
2193
2194
return XXH_OK;
2195
}
2196
2197
2198
/*! @ingroup xxh32_family */
2199
XXH_PUBLIC_API XXH32_hash_t XXH32_digest(const XXH32_state_t* state)
2200
{
2201
xxh_u32 h32;
2202
2203
if (state->large_len) {
2204
h32 = XXH_rotl32(state->v[0], 1)
2205
+ XXH_rotl32(state->v[1], 7)
2206
+ XXH_rotl32(state->v[2], 12)
2207
+ XXH_rotl32(state->v[3], 18);
2208
} else {
2209
h32 = state->v[2] /* == seed */ + XXH_PRIME32_5;
2210
}
2211
2212
h32 += state->total_len_32;
2213
2214
return XXH32_finalize(h32, (const xxh_u8*)state->mem32, state->memsize, XXH_aligned);
2215
}
2216
2217
2218
/******* Canonical representation *******/
2219
2220
/*!
2221
* @ingroup xxh32_family
2222
* The default return values from XXH functions are unsigned 32 and 64 bit
2223
* integers.
2224
*
2225
* The canonical representation uses big endian convention, the same convention
2226
* as human-readable numbers (large digits first).
2227
*
2228
* This way, hash values can be written into a file or buffer, remaining
2229
* comparable across different systems.
2230
*
2231
* The following functions allow transformation of hash values to and from their
2232
* canonical format.
2233
*/
2234
XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
2235
{
2236
/* XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t)); */
2237
if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
2238
XXH_memcpy(dst, &hash, sizeof(*dst));
2239
}
2240
/*! @ingroup xxh32_family */
2241
XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
2242
{
2243
return XXH_readBE32(src);
2244
}
2245
2246
2247
#ifndef XXH_NO_LONG_LONG
2248
2249
/* *******************************************************************
2250
* 64-bit hash functions
2251
*********************************************************************/
2252
/*!
2253
* @}
2254
* @ingroup impl
2255
* @{
2256
*/
2257
/******* Memory access *******/
2258
2259
typedef XXH64_hash_t xxh_u64;
2260
2261
#ifdef XXH_OLD_NAMES
2262
# define U64 xxh_u64
2263
#endif
2264
2265
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
2266
/*
2267
* Manual byteshift. Best for old compilers which don't inline memcpy.
2268
* We actually directly use XXH_readLE64 and XXH_readBE64.
2269
*/
2270
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
2271
2272
/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
2273
static xxh_u64 XXH_read64(const void* memPtr)
2274
{
2275
return *(const xxh_u64*) memPtr;
2276
}
2277
2278
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
2279
2280
/*
2281
* __pack instructions are safer, but compiler specific, hence potentially
2282
* problematic for some compilers.
2283
*
2284
* Currently only defined for GCC and ICC.
2285
*/
2286
#ifdef XXH_OLD_NAMES
2287
typedef union { xxh_u32 u32; xxh_u64 u64; } __attribute__((packed)) unalign64;
2288
#endif
2289
static xxh_u64 XXH_read64(const void* ptr)
2290
{
2291
typedef union { xxh_u32 u32; xxh_u64 u64; } __attribute__((packed)) xxh_unalign64;
2292
return ((const xxh_unalign64*)ptr)->u64;
2293
}
2294
2295
#else
2296
2297
/*
2298
* Portable and safe solution. Generally efficient.
2299
* see: https://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html
2300
*/
2301
static xxh_u64 XXH_read64(const void* memPtr)
2302
{
2303
xxh_u64 val;
2304
XXH_memcpy(&val, memPtr, sizeof(val));
2305
return val;
2306
}
2307
2308
#endif /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
2309
2310
#if defined(_MSC_VER) /* Visual Studio */
2311
# define XXH_swap64 _byteswap_uint64
2312
#elif XXH_GCC_VERSION >= 403
2313
# define XXH_swap64 __builtin_bswap64
2314
#else
2315
static xxh_u64 XXH_swap64(xxh_u64 x)
2316
{
2317
return ((x << 56) & 0xff00000000000000ULL) |
2318
((x << 40) & 0x00ff000000000000ULL) |
2319
((x << 24) & 0x0000ff0000000000ULL) |
2320
((x << 8) & 0x000000ff00000000ULL) |
2321
((x >> 8) & 0x00000000ff000000ULL) |
2322
((x >> 24) & 0x0000000000ff0000ULL) |
2323
((x >> 40) & 0x000000000000ff00ULL) |
2324
((x >> 56) & 0x00000000000000ffULL);
2325
}
2326
#endif
2327
2328
2329
/* XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load. */
2330
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
2331
2332
XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* memPtr)
2333
{
2334
const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
2335
return bytePtr[0]
2336
| ((xxh_u64)bytePtr[1] << 8)
2337
| ((xxh_u64)bytePtr[2] << 16)
2338
| ((xxh_u64)bytePtr[3] << 24)
2339
| ((xxh_u64)bytePtr[4] << 32)
2340
| ((xxh_u64)bytePtr[5] << 40)
2341
| ((xxh_u64)bytePtr[6] << 48)
2342
| ((xxh_u64)bytePtr[7] << 56);
2343
}
2344
2345
XXH_FORCE_INLINE xxh_u64 XXH_readBE64(const void* memPtr)
2346
{
2347
const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
2348
return bytePtr[7]
2349
| ((xxh_u64)bytePtr[6] << 8)
2350
| ((xxh_u64)bytePtr[5] << 16)
2351
| ((xxh_u64)bytePtr[4] << 24)
2352
| ((xxh_u64)bytePtr[3] << 32)
2353
| ((xxh_u64)bytePtr[2] << 40)
2354
| ((xxh_u64)bytePtr[1] << 48)
2355
| ((xxh_u64)bytePtr[0] << 56);
2356
}
2357
2358
#else
2359
XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* ptr)
2360
{
2361
return XXH_CPU_LITTLE_ENDIAN ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
2362
}
2363
2364
static xxh_u64 XXH_readBE64(const void* ptr)
2365
{
2366
return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
2367
}
2368
#endif
2369
2370
XXH_FORCE_INLINE xxh_u64
2371
XXH_readLE64_align(const void* ptr, XXH_alignment align)
2372
{
2373
if (align==XXH_unaligned)
2374
return XXH_readLE64(ptr);
2375
else
2376
return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u64*)ptr : XXH_swap64(*(const xxh_u64*)ptr);
2377
}
2378
2379
2380
/******* xxh64 *******/
2381
/*!
2382
* @}
2383
* @defgroup xxh64_impl XXH64 implementation
2384
* @ingroup impl
2385
* @{
2386
*/
2387
/* #define rather that static const, to be used as initializers */
2388
#define XXH_PRIME64_1 0x9E3779B185EBCA87ULL /*!< 0b1001111000110111011110011011000110000101111010111100101010000111 */
2389
#define XXH_PRIME64_2 0xC2B2AE3D27D4EB4FULL /*!< 0b1100001010110010101011100011110100100111110101001110101101001111 */
2390
#define XXH_PRIME64_3 0x165667B19E3779F9ULL /*!< 0b0001011001010110011001111011000110011110001101110111100111111001 */
2391
#define XXH_PRIME64_4 0x85EBCA77C2B2AE63ULL /*!< 0b1000010111101011110010100111011111000010101100101010111001100011 */
2392
#define XXH_PRIME64_5 0x27D4EB2F165667C5ULL /*!< 0b0010011111010100111010110010111100010110010101100110011111000101 */
2393
2394
#ifdef XXH_OLD_NAMES
2395
# define PRIME64_1 XXH_PRIME64_1
2396
# define PRIME64_2 XXH_PRIME64_2
2397
# define PRIME64_3 XXH_PRIME64_3
2398
# define PRIME64_4 XXH_PRIME64_4
2399
# define PRIME64_5 XXH_PRIME64_5
2400
#endif
2401
2402
static xxh_u64 XXH64_round(xxh_u64 acc, xxh_u64 input)
2403
{
2404
acc += input * XXH_PRIME64_2;
2405
acc = XXH_rotl64(acc, 31);
2406
acc *= XXH_PRIME64_1;
2407
return acc;
2408
}
2409
2410
static xxh_u64 XXH64_mergeRound(xxh_u64 acc, xxh_u64 val)
2411
{
2412
val = XXH64_round(0, val);
2413
acc ^= val;
2414
acc = acc * XXH_PRIME64_1 + XXH_PRIME64_4;
2415
return acc;
2416
}
2417
2418
static xxh_u64 XXH64_avalanche(xxh_u64 h64)
2419
{
2420
h64 ^= h64 >> 33;
2421
h64 *= XXH_PRIME64_2;
2422
h64 ^= h64 >> 29;
2423
h64 *= XXH_PRIME64_3;
2424
h64 ^= h64 >> 32;
2425
return h64;
2426
}
2427
2428
2429
#define XXH_get64bits(p) XXH_readLE64_align(p, align)
2430
2431
static xxh_u64
2432
XXH64_finalize(xxh_u64 h64, const xxh_u8* ptr, size_t len, XXH_alignment align)
2433
{
2434
if (ptr==NULL) XXH_ASSERT(len == 0);
2435
len &= 31;
2436
while (len >= 8) {
2437
xxh_u64 const k1 = XXH64_round(0, XXH_get64bits(ptr));
2438
ptr += 8;
2439
h64 ^= k1;
2440
h64 = XXH_rotl64(h64,27) * XXH_PRIME64_1 + XXH_PRIME64_4;
2441
len -= 8;
2442
}
2443
if (len >= 4) {
2444
h64 ^= (xxh_u64)(XXH_get32bits(ptr)) * XXH_PRIME64_1;
2445
ptr += 4;
2446
h64 = XXH_rotl64(h64, 23) * XXH_PRIME64_2 + XXH_PRIME64_3;
2447
len -= 4;
2448
}
2449
while (len > 0) {
2450
h64 ^= (*ptr++) * XXH_PRIME64_5;
2451
h64 = XXH_rotl64(h64, 11) * XXH_PRIME64_1;
2452
--len;
2453
}
2454
return XXH64_avalanche(h64);
2455
}
2456
2457
#ifdef XXH_OLD_NAMES
2458
# define PROCESS1_64 XXH_PROCESS1_64
2459
# define PROCESS4_64 XXH_PROCESS4_64
2460
# define PROCESS8_64 XXH_PROCESS8_64
2461
#else
2462
# undef XXH_PROCESS1_64
2463
# undef XXH_PROCESS4_64
2464
# undef XXH_PROCESS8_64
2465
#endif
2466
2467
XXH_FORCE_INLINE xxh_u64
2468
XXH64_endian_align(const xxh_u8* input, size_t len, xxh_u64 seed, XXH_alignment align)
2469
{
2470
xxh_u64 h64;
2471
if (input==NULL) XXH_ASSERT(len == 0);
2472
2473
if (len>=32) {
2474
const xxh_u8* const bEnd = input + len;
2475
const xxh_u8* const limit = bEnd - 31;
2476
xxh_u64 v1 = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
2477
xxh_u64 v2 = seed + XXH_PRIME64_2;
2478
xxh_u64 v3 = seed + 0;
2479
xxh_u64 v4 = seed - XXH_PRIME64_1;
2480
2481
do {
2482
v1 = XXH64_round(v1, XXH_get64bits(input)); input+=8;
2483
v2 = XXH64_round(v2, XXH_get64bits(input)); input+=8;
2484
v3 = XXH64_round(v3, XXH_get64bits(input)); input+=8;
2485
v4 = XXH64_round(v4, XXH_get64bits(input)); input+=8;
2486
} while (input<limit);
2487
2488
h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
2489
h64 = XXH64_mergeRound(h64, v1);
2490
h64 = XXH64_mergeRound(h64, v2);
2491
h64 = XXH64_mergeRound(h64, v3);
2492
h64 = XXH64_mergeRound(h64, v4);
2493
2494
} else {
2495
h64 = seed + XXH_PRIME64_5;
2496
}
2497
2498
h64 += (xxh_u64) len;
2499
2500
return XXH64_finalize(h64, input, len, align);
2501
}
2502
2503
2504
/*! @ingroup xxh64_family */
2505
XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t len, XXH64_hash_t seed)
2506
{
2507
#if 0
2508
/* Simple version, good for code maintenance, but unfortunately slow for small inputs */
2509
XXH64_state_t state;
2510
XXH64_reset(&state, seed);
2511
XXH64_update(&state, (const xxh_u8*)input, len);
2512
return XXH64_digest(&state);
2513
#else
2514
if (XXH_FORCE_ALIGN_CHECK) {
2515
if ((((size_t)input) & 7)==0) { /* Input is aligned, let's leverage the speed advantage */
2516
return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
2517
} }
2518
2519
return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);
2520
2521
#endif
2522
}
2523
2524
/******* Hash Streaming *******/
2525
2526
/*! @ingroup xxh64_family*/
2527
XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
2528
{
2529
return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
2530
}
2531
/*! @ingroup xxh64_family */
2532
XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
2533
{
2534
XXH_free(statePtr);
2535
return XXH_OK;
2536
}
2537
2538
/*! @ingroup xxh64_family */
2539
XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dstState, const XXH64_state_t* srcState)
2540
{
2541
XXH_memcpy(dstState, srcState, sizeof(*dstState));
2542
}
2543
2544
/*! @ingroup xxh64_family */
2545
XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, XXH64_hash_t seed)
2546
{
2547
XXH_ASSERT(statePtr != NULL);
2548
memset(statePtr, 0, sizeof(*statePtr));
2549
statePtr->v[0] = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
2550
statePtr->v[1] = seed + XXH_PRIME64_2;
2551
statePtr->v[2] = seed + 0;
2552
statePtr->v[3] = seed - XXH_PRIME64_1;
2553
return XXH_OK;
2554
}
2555
2556
/*! @ingroup xxh64_family */
2557
XXH_PUBLIC_API XXH_errorcode
2558
XXH64_update (XXH64_state_t* state, const void* input, size_t len)
2559
{
2560
if (input==NULL) {
2561
XXH_ASSERT(len == 0);
2562
return XXH_OK;
2563
}
2564
2565
{ const xxh_u8* p = (const xxh_u8*)input;
2566
const xxh_u8* const bEnd = p + len;
2567
2568
state->total_len += len;
2569
2570
if (state->memsize + len < 32) { /* fill in tmp buffer */
2571
XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, len);
2572
state->memsize += (xxh_u32)len;
2573
return XXH_OK;
2574
}
2575
2576
if (state->memsize) { /* tmp buffer is full */
2577
XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, 32-state->memsize);
2578
state->v[0] = XXH64_round(state->v[0], XXH_readLE64(state->mem64+0));
2579
state->v[1] = XXH64_round(state->v[1], XXH_readLE64(state->mem64+1));
2580
state->v[2] = XXH64_round(state->v[2], XXH_readLE64(state->mem64+2));
2581
state->v[3] = XXH64_round(state->v[3], XXH_readLE64(state->mem64+3));
2582
p += 32 - state->memsize;
2583
state->memsize = 0;
2584
}
2585
2586
if (p+32 <= bEnd) {
2587
const xxh_u8* const limit = bEnd - 32;
2588
2589
do {
2590
state->v[0] = XXH64_round(state->v[0], XXH_readLE64(p)); p+=8;
2591
state->v[1] = XXH64_round(state->v[1], XXH_readLE64(p)); p+=8;
2592
state->v[2] = XXH64_round(state->v[2], XXH_readLE64(p)); p+=8;
2593
state->v[3] = XXH64_round(state->v[3], XXH_readLE64(p)); p+=8;
2594
} while (p<=limit);
2595
2596
}
2597
2598
if (p < bEnd) {
2599
XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
2600
state->memsize = (unsigned)(bEnd-p);
2601
}
2602
}
2603
2604
return XXH_OK;
2605
}
2606
2607
2608
/*! @ingroup xxh64_family */
2609
XXH_PUBLIC_API XXH64_hash_t XXH64_digest(const XXH64_state_t* state)
2610
{
2611
xxh_u64 h64;
2612
2613
if (state->total_len >= 32) {
2614
h64 = XXH_rotl64(state->v[0], 1) + XXH_rotl64(state->v[1], 7) + XXH_rotl64(state->v[2], 12) + XXH_rotl64(state->v[3], 18);
2615
h64 = XXH64_mergeRound(h64, state->v[0]);
2616
h64 = XXH64_mergeRound(h64, state->v[1]);
2617
h64 = XXH64_mergeRound(h64, state->v[2]);
2618
h64 = XXH64_mergeRound(h64, state->v[3]);
2619
} else {
2620
h64 = state->v[2] /*seed*/ + XXH_PRIME64_5;
2621
}
2622
2623
h64 += (xxh_u64) state->total_len;
2624
2625
return XXH64_finalize(h64, (const xxh_u8*)state->mem64, (size_t)state->total_len, XXH_aligned);
2626
}
2627
2628
2629
/******* Canonical representation *******/
2630
2631
/*! @ingroup xxh64_family */
2632
XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
2633
{
2634
/* XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t)); */
2635
if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
2636
XXH_memcpy(dst, &hash, sizeof(*dst));
2637
}
2638
2639
/*! @ingroup xxh64_family */
2640
XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
2641
{
2642
return XXH_readBE64(src);
2643
}
2644
2645
#ifndef XXH_NO_XXH3
2646
2647
/* *********************************************************************
2648
* XXH3
2649
* New generation hash designed for speed on small keys and vectorization
2650
************************************************************************ */
2651
/*!
2652
* @}
2653
* @defgroup xxh3_impl XXH3 implementation
2654
* @ingroup impl
2655
* @{
2656
*/
2657
2658
/* === Compiler specifics === */
2659
2660
#if ((defined(sun) || defined(__sun)) && __cplusplus) /* Solaris includes __STDC_VERSION__ with C++. Tested with GCC 5.5 */
2661
# define XXH_RESTRICT /* disable */
2662
#elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* >= C99 */
2663
# define XXH_RESTRICT restrict
2664
#else
2665
/* Note: it might be useful to define __restrict or __restrict__ for some C++ compilers */
2666
# define XXH_RESTRICT /* disable */
2667
#endif
2668
2669
#if (defined(__GNUC__) && (__GNUC__ >= 3)) \
2670
|| (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) \
2671
|| defined(__clang__)
2672
# define XXH_likely(x) __builtin_expect(x, 1)
2673
# define XXH_unlikely(x) __builtin_expect(x, 0)
2674
#else
2675
# define XXH_likely(x) (x)
2676
# define XXH_unlikely(x) (x)
2677
#endif
2678
2679
#if defined(__GNUC__) || defined(__clang__)
2680
# if defined(__ARM_NEON__) || defined(__ARM_NEON) \
2681
|| defined(__aarch64__) || defined(_M_ARM) \
2682
|| defined(_M_ARM64) || defined(_M_ARM64EC)
2683
# define inline __inline__ /* circumvent a clang bug */
2684
# include <arm_neon.h>
2685
# undef inline
2686
# elif defined(__AVX2__)
2687
# include <immintrin.h>
2688
# elif defined(__SSE2__)
2689
# include <emmintrin.h>
2690
# endif
2691
#endif
2692
2693
#if defined(_MSC_VER)
2694
# include <intrin.h>
2695
#endif
2696
2697
/*
2698
* One goal of XXH3 is to make it fast on both 32-bit and 64-bit, while
2699
* remaining a true 64-bit/128-bit hash function.
2700
*
2701
* This is done by prioritizing a subset of 64-bit operations that can be
2702
* emulated without too many steps on the average 32-bit machine.
2703
*
2704
* For example, these two lines seem similar, and run equally fast on 64-bit:
2705
*
2706
* xxh_u64 x;
2707
* x ^= (x >> 47); // good
2708
* x ^= (x >> 13); // bad
2709
*
2710
* However, to a 32-bit machine, there is a major difference.
2711
*
2712
* x ^= (x >> 47) looks like this:
2713
*
2714
* x.lo ^= (x.hi >> (47 - 32));
2715
*
2716
* while x ^= (x >> 13) looks like this:
2717
*
2718
* // note: funnel shifts are not usually cheap.
2719
* x.lo ^= (x.lo >> 13) | (x.hi << (32 - 13));
2720
* x.hi ^= (x.hi >> 13);
2721
*
2722
* The first one is significantly faster than the second, simply because the
2723
* shift is larger than 32. This means:
2724
* - All the bits we need are in the upper 32 bits, so we can ignore the lower
2725
* 32 bits in the shift.
2726
* - The shift result will always fit in the lower 32 bits, and therefore,
2727
* we can ignore the upper 32 bits in the xor.
2728
*
2729
* Thanks to this optimization, XXH3 only requires these features to be efficient:
2730
*
2731
* - Usable unaligned access
2732
* - A 32-bit or 64-bit ALU
2733
* - If 32-bit, a decent ADC instruction
2734
* - A 32 or 64-bit multiply with a 64-bit result
2735
* - For the 128-bit variant, a decent byteswap helps short inputs.
2736
*
2737
* The first two are already required by XXH32, and almost all 32-bit and 64-bit
2738
* platforms which can run XXH32 can run XXH3 efficiently.
2739
*
2740
* Thumb-1, the classic 16-bit only subset of ARM's instruction set, is one
2741
* notable exception.
2742
*
2743
* First of all, Thumb-1 lacks support for the UMULL instruction which
2744
* performs the important long multiply. This means numerous __aeabi_lmul
2745
* calls.
2746
*
2747
* Second of all, the 8 functional registers are just not enough.
2748
* Setup for __aeabi_lmul, byteshift loads, pointers, and all arithmetic need
2749
* Lo registers, and this shuffling results in thousands more MOVs than A32.
2750
*
2751
* A32 and T32 don't have this limitation. They can access all 14 registers,
2752
* do a 32->64 multiply with UMULL, and the flexible operand allowing free
2753
* shifts is helpful, too.
2754
*
2755
* Therefore, we do a quick sanity check.
2756
*
2757
* If compiling Thumb-1 for a target which supports ARM instructions, we will
2758
* emit a warning, as it is not a "sane" platform to compile for.
2759
*
2760
* Usually, if this happens, it is because of an accident and you probably need
2761
* to specify -march, as you likely meant to compile for a newer architecture.
2762
*
2763
* Credit: large sections of the vectorial and asm source code paths
2764
* have been contributed by @easyaspi314
2765
*/
2766
#if defined(__thumb__) && !defined(__thumb2__) && defined(__ARM_ARCH_ISA_ARM)
2767
# warning "XXH3 is highly inefficient without ARM or Thumb-2."
2768
#endif
2769
2770
/* ==========================================
2771
* Vectorization detection
2772
* ========================================== */
2773
2774
#ifdef XXH_DOXYGEN
2775
/*!
2776
* @ingroup tuning
2777
* @brief Overrides the vectorization implementation chosen for XXH3.
2778
*
2779
* Can be defined to 0 to disable SIMD or any of the values mentioned in
2780
* @ref XXH_VECTOR_TYPE.
2781
*
2782
* If this is not defined, it uses predefined macros to determine the best
2783
* implementation.
2784
*/
2785
# define XXH_VECTOR XXH_SCALAR
2786
/*!
2787
* @ingroup tuning
2788
* @brief Possible values for @ref XXH_VECTOR.
2789
*
2790
* Note that these are actually implemented as macros.
2791
*
2792
* If this is not defined, it is detected automatically.
2793
* @ref XXH_X86DISPATCH overrides this.
2794
*/
2795
enum XXH_VECTOR_TYPE /* fake enum */ {
2796
XXH_SCALAR = 0, /*!< Portable scalar version */
2797
XXH_SSE2 = 1, /*!<
2798
* SSE2 for Pentium 4, Opteron, all x86_64.
2799
*
2800
* @note SSE2 is also guaranteed on Windows 10, macOS, and
2801
* Android x86.
2802
*/
2803
XXH_AVX2 = 2, /*!< AVX2 for Haswell and Bulldozer */
2804
XXH_AVX512 = 3, /*!< AVX512 for Skylake and Icelake */
2805
XXH_NEON = 4, /*!< NEON for most ARMv7-A and all AArch64 */
2806
XXH_VSX = 5, /*!< VSX and ZVector for POWER8/z13 (64-bit) */
2807
};
2808
/*!
2809
* @ingroup tuning
2810
* @brief Selects the minimum alignment for XXH3's accumulators.
2811
*
2812
* When using SIMD, this should match the alignment required for said vector
2813
* type, so, for example, 32 for AVX2.
2814
*
2815
* Default: Auto detected.
2816
*/
2817
# define XXH_ACC_ALIGN 8
2818
#endif
2819
2820
/* Actual definition */
2821
#ifndef XXH_DOXYGEN
2822
# define XXH_SCALAR 0
2823
# define XXH_SSE2 1
2824
# define XXH_AVX2 2
2825
# define XXH_AVX512 3
2826
# define XXH_NEON 4
2827
# define XXH_VSX 5
2828
#endif
2829
2830
#ifndef XXH_VECTOR /* can be defined on command line */
2831
# if ( \
2832
defined(__ARM_NEON__) || defined(__ARM_NEON) /* gcc */ \
2833
|| defined(_M_ARM) || defined(_M_ARM64) || defined(_M_ARM64EC) /* msvc */ \
2834
) && ( \
2835
defined(_WIN32) || defined(__LITTLE_ENDIAN__) /* little endian only */ \
2836
|| (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) \
2837
)
2838
# define XXH_VECTOR XXH_NEON
2839
# elif defined(__AVX512F__)
2840
# define XXH_VECTOR XXH_AVX512
2841
# elif defined(__AVX2__)
2842
# define XXH_VECTOR XXH_AVX2
2843
# elif defined(__SSE2__) || defined(_M_AMD64) || defined(_M_X64) || (defined(_M_IX86_FP) && (_M_IX86_FP == 2))
2844
# define XXH_VECTOR XXH_SSE2
2845
# elif (defined(__PPC64__) && defined(__POWER8_VECTOR__)) \
2846
|| (defined(__s390x__) && defined(__VEC__)) \
2847
&& defined(__GNUC__) /* TODO: IBM XL */
2848
# define XXH_VECTOR XXH_VSX
2849
# else
2850
# define XXH_VECTOR XXH_SCALAR
2851
# endif
2852
#endif
2853
2854
/*
2855
* Controls the alignment of the accumulator,
2856
* for compatibility with aligned vector loads, which are usually faster.
2857
*/
2858
#ifndef XXH_ACC_ALIGN
2859
# if defined(XXH_X86DISPATCH)
2860
# define XXH_ACC_ALIGN 64 /* for compatibility with avx512 */
2861
# elif XXH_VECTOR == XXH_SCALAR /* scalar */
2862
# define XXH_ACC_ALIGN 8
2863
# elif XXH_VECTOR == XXH_SSE2 /* sse2 */
2864
# define XXH_ACC_ALIGN 16
2865
# elif XXH_VECTOR == XXH_AVX2 /* avx2 */
2866
# define XXH_ACC_ALIGN 32
2867
# elif XXH_VECTOR == XXH_NEON /* neon */
2868
# define XXH_ACC_ALIGN 16
2869
# elif XXH_VECTOR == XXH_VSX /* vsx */
2870
# define XXH_ACC_ALIGN 16
2871
# elif XXH_VECTOR == XXH_AVX512 /* avx512 */
2872
# define XXH_ACC_ALIGN 64
2873
# endif
2874
#endif
2875
2876
#if defined(XXH_X86DISPATCH) || XXH_VECTOR == XXH_SSE2 \
2877
|| XXH_VECTOR == XXH_AVX2 || XXH_VECTOR == XXH_AVX512
2878
# define XXH_SEC_ALIGN XXH_ACC_ALIGN
2879
#else
2880
# define XXH_SEC_ALIGN 8
2881
#endif
2882
2883
/*
2884
* UGLY HACK:
2885
* GCC usually generates the best code with -O3 for xxHash.
2886
*
2887
* However, when targeting AVX2, it is overzealous in its unrolling resulting
2888
* in code roughly 3/4 the speed of Clang.
2889
*
2890
* There are other issues, such as GCC splitting _mm256_loadu_si256 into
2891
* _mm_loadu_si128 + _mm256_inserti128_si256. This is an optimization which
2892
* only applies to Sandy and Ivy Bridge... which don't even support AVX2.
2893
*
2894
* That is why when compiling the AVX2 version, it is recommended to use either
2895
* -O2 -mavx2 -march=haswell
2896
* or
2897
* -O2 -mavx2 -mno-avx256-split-unaligned-load
2898
* for decent performance, or to use Clang instead.
2899
*
2900
* Fortunately, we can control the first one with a pragma that forces GCC into
2901
* -O2, but the other one we can't control without "failed to inline always
2902
* inline function due to target mismatch" warnings.
2903
*/
2904
#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
2905
&& defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
2906
&& defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
2907
# pragma GCC push_options
2908
# pragma GCC optimize("-O2")
2909
#endif
2910
2911
2912
#if XXH_VECTOR == XXH_NEON
2913
/*
2914
* NEON's setup for vmlal_u32 is a little more complicated than it is on
2915
* SSE2, AVX2, and VSX.
2916
*
2917
* While PMULUDQ and VMULEUW both perform a mask, VMLAL.U32 performs an upcast.
2918
*
2919
* To do the same operation, the 128-bit 'Q' register needs to be split into
2920
* two 64-bit 'D' registers, performing this operation::
2921
*
2922
* [ a | b ]
2923
* | '---------. .--------' |
2924
* | x |
2925
* | .---------' '--------. |
2926
* [ a & 0xFFFFFFFF | b & 0xFFFFFFFF ],[ a >> 32 | b >> 32 ]
2927
*
2928
* Due to significant changes in aarch64, the fastest method for aarch64 is
2929
* completely different than the fastest method for ARMv7-A.
2930
*
2931
* ARMv7-A treats D registers as unions overlaying Q registers, so modifying
2932
* D11 will modify the high half of Q5. This is similar to how modifying AH
2933
* will only affect bits 8-15 of AX on x86.
2934
*
2935
* VZIP takes two registers, and puts even lanes in one register and odd lanes
2936
* in the other.
2937
*
2938
* On ARMv7-A, this strangely modifies both parameters in place instead of
2939
* taking the usual 3-operand form.
2940
*
2941
* Therefore, if we want to do this, we can simply use a D-form VZIP.32 on the
2942
* lower and upper halves of the Q register to end up with the high and low
2943
* halves where we want - all in one instruction.
2944
*
2945
* vzip.32 d10, d11 @ d10 = { d10[0], d11[0] }; d11 = { d10[1], d11[1] }
2946
*
2947
* Unfortunately we need inline assembly for this: Instructions modifying two
2948
* registers at once is not possible in GCC or Clang's IR, and they have to
2949
* create a copy.
2950
*
2951
* aarch64 requires a different approach.
2952
*
2953
* In order to make it easier to write a decent compiler for aarch64, many
2954
* quirks were removed, such as conditional execution.
2955
*
2956
* NEON was also affected by this.
2957
*
2958
* aarch64 cannot access the high bits of a Q-form register, and writes to a
2959
* D-form register zero the high bits, similar to how writes to W-form scalar
2960
* registers (or DWORD registers on x86_64) work.
2961
*
2962
* The formerly free vget_high intrinsics now require a vext (with a few
2963
* exceptions)
2964
*
2965
* Additionally, VZIP was replaced by ZIP1 and ZIP2, which are the equivalent
2966
* of PUNPCKL* and PUNPCKH* in SSE, respectively, in order to only modify one
2967
* operand.
2968
*
2969
* The equivalent of the VZIP.32 on the lower and upper halves would be this
2970
* mess:
2971
*
2972
* ext v2.4s, v0.4s, v0.4s, #2 // v2 = { v0[2], v0[3], v0[0], v0[1] }
2973
* zip1 v1.2s, v0.2s, v2.2s // v1 = { v0[0], v2[0] }
2974
* zip2 v0.2s, v0.2s, v1.2s // v0 = { v0[1], v2[1] }
2975
*
2976
* Instead, we use a literal downcast, vmovn_u64 (XTN), and vshrn_n_u64 (SHRN):
2977
*
2978
* shrn v1.2s, v0.2d, #32 // v1 = (uint32x2_t)(v0 >> 32);
2979
* xtn v0.2s, v0.2d // v0 = (uint32x2_t)(v0 & 0xFFFFFFFF);
2980
*
2981
* This is available on ARMv7-A, but is less efficient than a single VZIP.32.
2982
*/
2983
2984
/*!
2985
* Function-like macro:
2986
* void XXH_SPLIT_IN_PLACE(uint64x2_t &in, uint32x2_t &outLo, uint32x2_t &outHi)
2987
* {
2988
* outLo = (uint32x2_t)(in & 0xFFFFFFFF);
2989
* outHi = (uint32x2_t)(in >> 32);
2990
* in = UNDEFINED;
2991
* }
2992
*/
2993
# if !defined(XXH_NO_VZIP_HACK) /* define to disable */ \
2994
&& (defined(__GNUC__) || defined(__clang__)) \
2995
&& (defined(__arm__) || defined(__thumb__) || defined(_M_ARM))
2996
# define XXH_SPLIT_IN_PLACE(in, outLo, outHi) \
2997
do { \
2998
/* Undocumented GCC/Clang operand modifier: %e0 = lower D half, %f0 = upper D half */ \
2999
/* https://github.com/gcc-mirror/gcc/blob/38cf91e5/gcc/config/arm/arm.c#L22486 */ \
3000
/* https://github.com/llvm-mirror/llvm/blob/2c4ca683/lib/Target/ARM/ARMAsmPrinter.cpp#L399 */ \
3001
__asm__("vzip.32 %e0, %f0" : "+w" (in)); \
3002
(outLo) = vget_low_u32 (vreinterpretq_u32_u64(in)); \
3003
(outHi) = vget_high_u32(vreinterpretq_u32_u64(in)); \
3004
} while (0)
3005
# else
3006
# define XXH_SPLIT_IN_PLACE(in, outLo, outHi) \
3007
do { \
3008
(outLo) = vmovn_u64 (in); \
3009
(outHi) = vshrn_n_u64 ((in), 32); \
3010
} while (0)
3011
# endif
3012
3013
/*!
3014
* @ingroup tuning
3015
* @brief Controls the NEON to scalar ratio for XXH3
3016
*
3017
* On AArch64 when not optimizing for size, XXH3 will run 6 lanes using NEON and
3018
* 2 lanes on scalar by default.
3019
*
3020
* This can be set to 2, 4, 6, or 8. ARMv7 will default to all 8 NEON lanes, as the
3021
* emulated 64-bit arithmetic is too slow.
3022
*
3023
* Modern ARM CPUs are _very_ sensitive to how their pipelines are used.
3024
*
3025
* For example, the Cortex-A73 can dispatch 3 micro-ops per cycle, but it can't
3026
* have more than 2 NEON (F0/F1) micro-ops. If you are only using NEON instructions,
3027
* you are only using 2/3 of the CPU bandwidth.
3028
*
3029
* This is even more noticeable on the more advanced cores like the A76 which
3030
* can dispatch 8 micro-ops per cycle, but still only 2 NEON micro-ops at once.
3031
*
3032
* Therefore, @ref XXH3_NEON_LANES lanes will be processed using NEON, and the
3033
* remaining lanes will use scalar instructions. This improves the bandwidth
3034
* and also gives the integer pipelines something to do besides twiddling loop
3035
* counters and pointers.
3036
*
3037
* This change benefits CPUs with large micro-op buffers without negatively affecting
3038
* other CPUs:
3039
*
3040
* | Chipset | Dispatch type | NEON only | 6:2 hybrid | Diff. |
3041
* |:----------------------|:--------------------|----------:|-----------:|------:|
3042
* | Snapdragon 730 (A76) | 2 NEON/8 micro-ops | 8.8 GB/s | 10.1 GB/s | ~16% |
3043
* | Snapdragon 835 (A73) | 2 NEON/3 micro-ops | 5.1 GB/s | 5.3 GB/s | ~5% |
3044
* | Marvell PXA1928 (A53) | In-order dual-issue | 1.9 GB/s | 1.9 GB/s | 0% |
3045
*
3046
* It also seems to fix some bad codegen on GCC, making it almost as fast as clang.
3047
*
3048
* @see XXH3_accumulate_512_neon()
3049
*/
3050
# ifndef XXH3_NEON_LANES
3051
# if (defined(__aarch64__) || defined(__arm64__) || defined(_M_ARM64) || defined(_M_ARM64EC)) \
3052
&& !defined(__OPTIMIZE_SIZE__)
3053
# define XXH3_NEON_LANES 6
3054
# else
3055
# define XXH3_NEON_LANES XXH_ACC_NB
3056
# endif
3057
# endif
3058
#endif /* XXH_VECTOR == XXH_NEON */
3059
3060
/*
3061
* VSX and Z Vector helpers.
3062
*
3063
* This is very messy, and any pull requests to clean this up are welcome.
3064
*
3065
* There are a lot of problems with supporting VSX and s390x, due to
3066
* inconsistent intrinsics, spotty coverage, and multiple endiannesses.
3067
*/
3068
#if XXH_VECTOR == XXH_VSX
3069
# if defined(__s390x__)
3070
# include <s390intrin.h>
3071
# else
3072
/* gcc's altivec.h can have the unwanted consequence to unconditionally
3073
* #define bool, vector, and pixel keywords,
3074
* with bad consequences for programs already using these keywords for other purposes.
3075
* The paragraph defining these macros is skipped when __APPLE_ALTIVEC__ is defined.
3076
* __APPLE_ALTIVEC__ is _generally_ defined automatically by the compiler,
3077
* but it seems that, in some cases, it isn't.
3078
* Force the build macro to be defined, so that keywords are not altered.
3079
*/
3080
# if defined(__GNUC__) && !defined(__APPLE_ALTIVEC__)
3081
# define __APPLE_ALTIVEC__
3082
# endif
3083
# include <altivec.h>
3084
# endif
3085
3086
typedef __vector unsigned long long xxh_u64x2;
3087
typedef __vector unsigned char xxh_u8x16;
3088
typedef __vector unsigned xxh_u32x4;
3089
3090
# ifndef XXH_VSX_BE
3091
# if defined(__BIG_ENDIAN__) \
3092
|| (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
3093
# define XXH_VSX_BE 1
3094
# elif defined(__VEC_ELEMENT_REG_ORDER__) && __VEC_ELEMENT_REG_ORDER__ == __ORDER_BIG_ENDIAN__
3095
# warning "-maltivec=be is not recommended. Please use native endianness."
3096
# define XXH_VSX_BE 1
3097
# else
3098
# define XXH_VSX_BE 0
3099
# endif
3100
# endif /* !defined(XXH_VSX_BE) */
3101
3102
# if XXH_VSX_BE
3103
# if defined(__POWER9_VECTOR__) || (defined(__clang__) && defined(__s390x__))
3104
# define XXH_vec_revb vec_revb
3105
# else
3106
/*!
3107
* A polyfill for POWER9's vec_revb().
3108
*/
3109
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_revb(xxh_u64x2 val)
3110
{
3111
xxh_u8x16 const vByteSwap = { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
3112
0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08 };
3113
return vec_perm(val, val, vByteSwap);
3114
}
3115
# endif
3116
# endif /* XXH_VSX_BE */
3117
3118
/*!
3119
* Performs an unaligned vector load and byte swaps it on big endian.
3120
*/
3121
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_loadu(const void *ptr)
3122
{
3123
xxh_u64x2 ret;
3124
XXH_memcpy(&ret, ptr, sizeof(xxh_u64x2));
3125
# if XXH_VSX_BE
3126
ret = XXH_vec_revb(ret);
3127
# endif
3128
return ret;
3129
}
3130
3131
/*
3132
* vec_mulo and vec_mule are very problematic intrinsics on PowerPC
3133
*
3134
* These intrinsics weren't added until GCC 8, despite existing for a while,
3135
* and they are endian dependent. Also, their meaning swap depending on version.
3136
* */
3137
# if defined(__s390x__)
3138
/* s390x is always big endian, no issue on this platform */
3139
# define XXH_vec_mulo vec_mulo
3140
# define XXH_vec_mule vec_mule
3141
# elif defined(__clang__) && XXH_HAS_BUILTIN(__builtin_altivec_vmuleuw)
3142
/* Clang has a better way to control this, we can just use the builtin which doesn't swap. */
3143
# define XXH_vec_mulo __builtin_altivec_vmulouw
3144
# define XXH_vec_mule __builtin_altivec_vmuleuw
3145
# else
3146
/* gcc needs inline assembly */
3147
/* Adapted from https://github.com/google/highwayhash/blob/master/highwayhash/hh_vsx.h. */
3148
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mulo(xxh_u32x4 a, xxh_u32x4 b)
3149
{
3150
xxh_u64x2 result;
3151
__asm__("vmulouw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
3152
return result;
3153
}
3154
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mule(xxh_u32x4 a, xxh_u32x4 b)
3155
{
3156
xxh_u64x2 result;
3157
__asm__("vmuleuw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
3158
return result;
3159
}
3160
# endif /* XXH_vec_mulo, XXH_vec_mule */
3161
#endif /* XXH_VECTOR == XXH_VSX */
3162
3163
3164
/* prefetch
3165
* can be disabled, by declaring XXH_NO_PREFETCH build macro */
3166
#if defined(XXH_NO_PREFETCH)
3167
# define XXH_PREFETCH(ptr) (void)(ptr) /* disabled */
3168
#else
3169
# if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_IX86)) /* _mm_prefetch() not defined outside of x86/x64 */
3170
# include <mmintrin.h> /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
3171
# define XXH_PREFETCH(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
3172
# elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
3173
# define XXH_PREFETCH(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
3174
# else
3175
# define XXH_PREFETCH(ptr) (void)(ptr) /* disabled */
3176
# endif
3177
#endif /* XXH_NO_PREFETCH */
3178
3179
3180
/* ==========================================
3181
* XXH3 default settings
3182
* ========================================== */
3183
3184
#define XXH_SECRET_DEFAULT_SIZE 192 /* minimum XXH3_SECRET_SIZE_MIN */
3185
3186
#if (XXH_SECRET_DEFAULT_SIZE < XXH3_SECRET_SIZE_MIN)
3187
# error "default keyset is not large enough"
3188
#endif
3189
3190
/*! Pseudorandom secret taken directly from FARSH. */
3191
XXH_ALIGN(64) static const xxh_u8 XXH3_kSecret[XXH_SECRET_DEFAULT_SIZE] = {
3192
0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c,
3193
0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f,
3194
0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,
3195
0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c,
3196
0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3,
3197
0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,
3198
0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d,
3199
0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64,
3200
0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,
3201
0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e,
3202
0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce,
3203
0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,
3204
};
3205
3206
3207
#ifdef XXH_OLD_NAMES
3208
# define kSecret XXH3_kSecret
3209
#endif
3210
3211
#ifdef XXH_DOXYGEN
3212
/*!
3213
* @brief Calculates a 32-bit to 64-bit long multiply.
3214
*
3215
* Implemented as a macro.
3216
*
3217
* Wraps `__emulu` on MSVC x86 because it tends to call `__allmul` when it doesn't
3218
* need to (but it shouldn't need to anyways, it is about 7 instructions to do
3219
* a 64x64 multiply...). Since we know that this will _always_ emit `MULL`, we
3220
* use that instead of the normal method.
3221
*
3222
* If you are compiling for platforms like Thumb-1 and don't have a better option,
3223
* you may also want to write your own long multiply routine here.
3224
*
3225
* @param x, y Numbers to be multiplied
3226
* @return 64-bit product of the low 32 bits of @p x and @p y.
3227
*/
3228
XXH_FORCE_INLINE xxh_u64
3229
XXH_mult32to64(xxh_u64 x, xxh_u64 y)
3230
{
3231
return (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF);
3232
}
3233
#elif defined(_MSC_VER) && defined(_M_IX86)
3234
# define XXH_mult32to64(x, y) __emulu((unsigned)(x), (unsigned)(y))
3235
#else
3236
/*
3237
* Downcast + upcast is usually better than masking on older compilers like
3238
* GCC 4.2 (especially 32-bit ones), all without affecting newer compilers.
3239
*
3240
* The other method, (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF), will AND both operands
3241
* and perform a full 64x64 multiply -- entirely redundant on 32-bit.
3242
*/
3243
# define XXH_mult32to64(x, y) ((xxh_u64)(xxh_u32)(x) * (xxh_u64)(xxh_u32)(y))
3244
#endif
3245
3246
/*!
3247
* @brief Calculates a 64->128-bit long multiply.
3248
*
3249
* Uses `__uint128_t` and `_umul128` if available, otherwise uses a scalar
3250
* version.
3251
*
3252
* @param lhs , rhs The 64-bit integers to be multiplied
3253
* @return The 128-bit result represented in an @ref XXH128_hash_t.
3254
*/
3255
static XXH128_hash_t
3256
XXH_mult64to128(xxh_u64 lhs, xxh_u64 rhs)
3257
{
3258
/*
3259
* GCC/Clang __uint128_t method.
3260
*
3261
* On most 64-bit targets, GCC and Clang define a __uint128_t type.
3262
* This is usually the best way as it usually uses a native long 64-bit
3263
* multiply, such as MULQ on x86_64 or MUL + UMULH on aarch64.
3264
*
3265
* Usually.
3266
*
3267
* Despite being a 32-bit platform, Clang (and emscripten) define this type
3268
* despite not having the arithmetic for it. This results in a laggy
3269
* compiler builtin call which calculates a full 128-bit multiply.
3270
* In that case it is best to use the portable one.
3271
* https://github.com/Cyan4973/xxHash/issues/211#issuecomment-515575677
3272
*/
3273
#if (defined(__GNUC__) || defined(__clang__)) && !defined(__wasm__) \
3274
&& defined(__SIZEOF_INT128__) \
3275
|| (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
3276
3277
__uint128_t const product = (__uint128_t)lhs * (__uint128_t)rhs;
3278
XXH128_hash_t r128;
3279
r128.low64 = (xxh_u64)(product);
3280
r128.high64 = (xxh_u64)(product >> 64);
3281
return r128;
3282
3283
/*
3284
* MSVC for x64's _umul128 method.
3285
*
3286
* xxh_u64 _umul128(xxh_u64 Multiplier, xxh_u64 Multiplicand, xxh_u64 *HighProduct);
3287
*
3288
* This compiles to single operand MUL on x64.
3289
*/
3290
#elif (defined(_M_X64) || defined(_M_IA64)) && !defined(_M_ARM64EC)
3291
3292
#ifndef _MSC_VER
3293
# pragma intrinsic(_umul128)
3294
#endif
3295
xxh_u64 product_high;
3296
xxh_u64 const product_low = _umul128(lhs, rhs, &product_high);
3297
XXH128_hash_t r128;
3298
r128.low64 = product_low;
3299
r128.high64 = product_high;
3300
return r128;
3301
3302
/*
3303
* MSVC for ARM64's __umulh method.
3304
*
3305
* This compiles to the same MUL + UMULH as GCC/Clang's __uint128_t method.
3306
*/
3307
#elif defined(_M_ARM64) || defined(_M_ARM64EC)
3308
3309
#ifndef _MSC_VER
3310
# pragma intrinsic(__umulh)
3311
#endif
3312
XXH128_hash_t r128;
3313
r128.low64 = lhs * rhs;
3314
r128.high64 = __umulh(lhs, rhs);
3315
return r128;
3316
3317
#else
3318
/*
3319
* Portable scalar method. Optimized for 32-bit and 64-bit ALUs.
3320
*
3321
* This is a fast and simple grade school multiply, which is shown below
3322
* with base 10 arithmetic instead of base 0x100000000.
3323
*
3324
* 9 3 // D2 lhs = 93
3325
* x 7 5 // D2 rhs = 75
3326
* ----------
3327
* 1 5 // D2 lo_lo = (93 % 10) * (75 % 10) = 15
3328
* 4 5 | // D2 hi_lo = (93 / 10) * (75 % 10) = 45
3329
* 2 1 | // D2 lo_hi = (93 % 10) * (75 / 10) = 21
3330
* + 6 3 | | // D2 hi_hi = (93 / 10) * (75 / 10) = 63
3331
* ---------
3332
* 2 7 | // D2 cross = (15 / 10) + (45 % 10) + 21 = 27
3333
* + 6 7 | | // D2 upper = (27 / 10) + (45 / 10) + 63 = 67
3334
* ---------
3335
* 6 9 7 5 // D4 res = (27 * 10) + (15 % 10) + (67 * 100) = 6975
3336
*
3337
* The reasons for adding the products like this are:
3338
* 1. It avoids manual carry tracking. Just like how
3339
* (9 * 9) + 9 + 9 = 99, the same applies with this for UINT64_MAX.
3340
* This avoids a lot of complexity.
3341
*
3342
* 2. It hints for, and on Clang, compiles to, the powerful UMAAL
3343
* instruction available in ARM's Digital Signal Processing extension
3344
* in 32-bit ARMv6 and later, which is shown below:
3345
*
3346
* void UMAAL(xxh_u32 *RdLo, xxh_u32 *RdHi, xxh_u32 Rn, xxh_u32 Rm)
3347
* {
3348
* xxh_u64 product = (xxh_u64)*RdLo * (xxh_u64)*RdHi + Rn + Rm;
3349
* *RdLo = (xxh_u32)(product & 0xFFFFFFFF);
3350
* *RdHi = (xxh_u32)(product >> 32);
3351
* }
3352
*
3353
* This instruction was designed for efficient long multiplication, and
3354
* allows this to be calculated in only 4 instructions at speeds
3355
* comparable to some 64-bit ALUs.
3356
*
3357
* 3. It isn't terrible on other platforms. Usually this will be a couple
3358
* of 32-bit ADD/ADCs.
3359
*/
3360
3361
/* First calculate all of the cross products. */
3362
xxh_u64 const lo_lo = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs & 0xFFFFFFFF);
3363
xxh_u64 const hi_lo = XXH_mult32to64(lhs >> 32, rhs & 0xFFFFFFFF);
3364
xxh_u64 const lo_hi = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs >> 32);
3365
xxh_u64 const hi_hi = XXH_mult32to64(lhs >> 32, rhs >> 32);
3366
3367
/* Now add the products together. These will never overflow. */
3368
xxh_u64 const cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi;
3369
xxh_u64 const upper = (hi_lo >> 32) + (cross >> 32) + hi_hi;
3370
xxh_u64 const lower = (cross << 32) | (lo_lo & 0xFFFFFFFF);
3371
3372
XXH128_hash_t r128;
3373
r128.low64 = lower;
3374
r128.high64 = upper;
3375
return r128;
3376
#endif
3377
}
3378
3379
/*!
3380
* @brief Calculates a 64-bit to 128-bit multiply, then XOR folds it.
3381
*
3382
* The reason for the separate function is to prevent passing too many structs
3383
* around by value. This will hopefully inline the multiply, but we don't force it.
3384
*
3385
* @param lhs , rhs The 64-bit integers to multiply
3386
* @return The low 64 bits of the product XOR'd by the high 64 bits.
3387
* @see XXH_mult64to128()
3388
*/
3389
static xxh_u64
3390
XXH3_mul128_fold64(xxh_u64 lhs, xxh_u64 rhs)
3391
{
3392
XXH128_hash_t product = XXH_mult64to128(lhs, rhs);
3393
return product.low64 ^ product.high64;
3394
}
3395
3396
/*! Seems to produce slightly better code on GCC for some reason. */
3397
XXH_FORCE_INLINE xxh_u64 XXH_xorshift64(xxh_u64 v64, int shift)
3398
{
3399
XXH_ASSERT(0 <= shift && shift < 64);
3400
return v64 ^ (v64 >> shift);
3401
}
3402
3403
/*
3404
* This is a fast avalanche stage,
3405
* suitable when input bits are already partially mixed
3406
*/
3407
static XXH64_hash_t XXH3_avalanche(xxh_u64 h64)
3408
{
3409
h64 = XXH_xorshift64(h64, 37);
3410
h64 *= 0x165667919E3779F9ULL;
3411
h64 = XXH_xorshift64(h64, 32);
3412
return h64;
3413
}
3414
3415
/*
3416
* This is a stronger avalanche,
3417
* inspired by Pelle Evensen's rrmxmx
3418
* preferable when input has not been previously mixed
3419
*/
3420
static XXH64_hash_t XXH3_rrmxmx(xxh_u64 h64, xxh_u64 len)
3421
{
3422
/* this mix is inspired by Pelle Evensen's rrmxmx */
3423
h64 ^= XXH_rotl64(h64, 49) ^ XXH_rotl64(h64, 24);
3424
h64 *= 0x9FB21C651E98DF25ULL;
3425
h64 ^= (h64 >> 35) + len ;
3426
h64 *= 0x9FB21C651E98DF25ULL;
3427
return XXH_xorshift64(h64, 28);
3428
}
3429
3430
3431
/* ==========================================
3432
* Short keys
3433
* ==========================================
3434
* One of the shortcomings of XXH32 and XXH64 was that their performance was
3435
* sub-optimal on short lengths. It used an iterative algorithm which strongly
3436
* favored lengths that were a multiple of 4 or 8.
3437
*
3438
* Instead of iterating over individual inputs, we use a set of single shot
3439
* functions which piece together a range of lengths and operate in constant time.
3440
*
3441
* Additionally, the number of multiplies has been significantly reduced. This
3442
* reduces latency, especially when emulating 64-bit multiplies on 32-bit.
3443
*
3444
* Depending on the platform, this may or may not be faster than XXH32, but it
3445
* is almost guaranteed to be faster than XXH64.
3446
*/
3447
3448
/*
3449
* At very short lengths, there isn't enough input to fully hide secrets, or use
3450
* the entire secret.
3451
*
3452
* There is also only a limited amount of mixing we can do before significantly
3453
* impacting performance.
3454
*
3455
* Therefore, we use different sections of the secret and always mix two secret
3456
* samples with an XOR. This should have no effect on performance on the
3457
* seedless or withSeed variants because everything _should_ be constant folded
3458
* by modern compilers.
3459
*
3460
* The XOR mixing hides individual parts of the secret and increases entropy.
3461
*
3462
* This adds an extra layer of strength for custom secrets.
3463
*/
3464
XXH_FORCE_INLINE XXH64_hash_t
3465
XXH3_len_1to3_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3466
{
3467
XXH_ASSERT(input != NULL);
3468
XXH_ASSERT(1 <= len && len <= 3);
3469
XXH_ASSERT(secret != NULL);
3470
/*
3471
* len = 1: combined = { input[0], 0x01, input[0], input[0] }
3472
* len = 2: combined = { input[1], 0x02, input[0], input[1] }
3473
* len = 3: combined = { input[2], 0x03, input[0], input[1] }
3474
*/
3475
{ xxh_u8 const c1 = input[0];
3476
xxh_u8 const c2 = input[len >> 1];
3477
xxh_u8 const c3 = input[len - 1];
3478
xxh_u32 const combined = ((xxh_u32)c1 << 16) | ((xxh_u32)c2 << 24)
3479
| ((xxh_u32)c3 << 0) | ((xxh_u32)len << 8);
3480
xxh_u64 const bitflip = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
3481
xxh_u64 const keyed = (xxh_u64)combined ^ bitflip;
3482
return XXH64_avalanche(keyed);
3483
}
3484
}
3485
3486
XXH_FORCE_INLINE XXH64_hash_t
3487
XXH3_len_4to8_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3488
{
3489
XXH_ASSERT(input != NULL);
3490
XXH_ASSERT(secret != NULL);
3491
XXH_ASSERT(4 <= len && len <= 8);
3492
seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
3493
{ xxh_u32 const input1 = XXH_readLE32(input);
3494
xxh_u32 const input2 = XXH_readLE32(input + len - 4);
3495
xxh_u64 const bitflip = (XXH_readLE64(secret+8) ^ XXH_readLE64(secret+16)) - seed;
3496
xxh_u64 const input64 = input2 + (((xxh_u64)input1) << 32);
3497
xxh_u64 const keyed = input64 ^ bitflip;
3498
return XXH3_rrmxmx(keyed, len);
3499
}
3500
}
3501
3502
XXH_FORCE_INLINE XXH64_hash_t
3503
XXH3_len_9to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3504
{
3505
XXH_ASSERT(input != NULL);
3506
XXH_ASSERT(secret != NULL);
3507
XXH_ASSERT(9 <= len && len <= 16);
3508
{ xxh_u64 const bitflip1 = (XXH_readLE64(secret+24) ^ XXH_readLE64(secret+32)) + seed;
3509
xxh_u64 const bitflip2 = (XXH_readLE64(secret+40) ^ XXH_readLE64(secret+48)) - seed;
3510
xxh_u64 const input_lo = XXH_readLE64(input) ^ bitflip1;
3511
xxh_u64 const input_hi = XXH_readLE64(input + len - 8) ^ bitflip2;
3512
xxh_u64 const acc = len
3513
+ XXH_swap64(input_lo) + input_hi
3514
+ XXH3_mul128_fold64(input_lo, input_hi);
3515
return XXH3_avalanche(acc);
3516
}
3517
}
3518
3519
XXH_FORCE_INLINE XXH64_hash_t
3520
XXH3_len_0to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3521
{
3522
XXH_ASSERT(len <= 16);
3523
{ if (XXH_likely(len > 8)) return XXH3_len_9to16_64b(input, len, secret, seed);
3524
if (XXH_likely(len >= 4)) return XXH3_len_4to8_64b(input, len, secret, seed);
3525
if (len) return XXH3_len_1to3_64b(input, len, secret, seed);
3526
return XXH64_avalanche(seed ^ (XXH_readLE64(secret+56) ^ XXH_readLE64(secret+64)));
3527
}
3528
}
3529
3530
/*
3531
* DISCLAIMER: There are known *seed-dependent* multicollisions here due to
3532
* multiplication by zero, affecting hashes of lengths 17 to 240.
3533
*
3534
* However, they are very unlikely.
3535
*
3536
* Keep this in mind when using the unseeded XXH3_64bits() variant: As with all
3537
* unseeded non-cryptographic hashes, it does not attempt to defend itself
3538
* against specially crafted inputs, only random inputs.
3539
*
3540
* Compared to classic UMAC where a 1 in 2^31 chance of 4 consecutive bytes
3541
* cancelling out the secret is taken an arbitrary number of times (addressed
3542
* in XXH3_accumulate_512), this collision is very unlikely with random inputs
3543
* and/or proper seeding:
3544
*
3545
* This only has a 1 in 2^63 chance of 8 consecutive bytes cancelling out, in a
3546
* function that is only called up to 16 times per hash with up to 240 bytes of
3547
* input.
3548
*
3549
* This is not too bad for a non-cryptographic hash function, especially with
3550
* only 64 bit outputs.
3551
*
3552
* The 128-bit variant (which trades some speed for strength) is NOT affected
3553
* by this, although it is always a good idea to use a proper seed if you care
3554
* about strength.
3555
*/
3556
XXH_FORCE_INLINE xxh_u64 XXH3_mix16B(const xxh_u8* XXH_RESTRICT input,
3557
const xxh_u8* XXH_RESTRICT secret, xxh_u64 seed64)
3558
{
3559
#if defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
3560
&& defined(__i386__) && defined(__SSE2__) /* x86 + SSE2 */ \
3561
&& !defined(XXH_ENABLE_AUTOVECTORIZE) /* Define to disable like XXH32 hack */
3562
/*
3563
* UGLY HACK:
3564
* GCC for x86 tends to autovectorize the 128-bit multiply, resulting in
3565
* slower code.
3566
*
3567
* By forcing seed64 into a register, we disrupt the cost model and
3568
* cause it to scalarize. See `XXH32_round()`
3569
*
3570
* FIXME: Clang's output is still _much_ faster -- On an AMD Ryzen 3600,
3571
* XXH3_64bits @ len=240 runs at 4.6 GB/s with Clang 9, but 3.3 GB/s on
3572
* GCC 9.2, despite both emitting scalar code.
3573
*
3574
* GCC generates much better scalar code than Clang for the rest of XXH3,
3575
* which is why finding a more optimal codepath is an interest.
3576
*/
3577
XXH_COMPILER_GUARD(seed64);
3578
#endif
3579
{ xxh_u64 const input_lo = XXH_readLE64(input);
3580
xxh_u64 const input_hi = XXH_readLE64(input+8);
3581
return XXH3_mul128_fold64(
3582
input_lo ^ (XXH_readLE64(secret) + seed64),
3583
input_hi ^ (XXH_readLE64(secret+8) - seed64)
3584
);
3585
}
3586
}
3587
3588
/* For mid range keys, XXH3 uses a Mum-hash variant. */
3589
XXH_FORCE_INLINE XXH64_hash_t
3590
XXH3_len_17to128_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
3591
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
3592
XXH64_hash_t seed)
3593
{
3594
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
3595
XXH_ASSERT(16 < len && len <= 128);
3596
3597
{ xxh_u64 acc = len * XXH_PRIME64_1;
3598
if (len > 32) {
3599
if (len > 64) {
3600
if (len > 96) {
3601
acc += XXH3_mix16B(input+48, secret+96, seed);
3602
acc += XXH3_mix16B(input+len-64, secret+112, seed);
3603
}
3604
acc += XXH3_mix16B(input+32, secret+64, seed);
3605
acc += XXH3_mix16B(input+len-48, secret+80, seed);
3606
}
3607
acc += XXH3_mix16B(input+16, secret+32, seed);
3608
acc += XXH3_mix16B(input+len-32, secret+48, seed);
3609
}
3610
acc += XXH3_mix16B(input+0, secret+0, seed);
3611
acc += XXH3_mix16B(input+len-16, secret+16, seed);
3612
3613
return XXH3_avalanche(acc);
3614
}
3615
}
3616
3617
#define XXH3_MIDSIZE_MAX 240
3618
3619
XXH_NO_INLINE XXH64_hash_t
3620
XXH3_len_129to240_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
3621
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
3622
XXH64_hash_t seed)
3623
{
3624
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
3625
XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
3626
3627
#define XXH3_MIDSIZE_STARTOFFSET 3
3628
#define XXH3_MIDSIZE_LASTOFFSET 17
3629
3630
{ xxh_u64 acc = len * XXH_PRIME64_1;
3631
int const nbRounds = (int)len / 16;
3632
int i;
3633
for (i=0; i<8; i++) {
3634
acc += XXH3_mix16B(input+(16*i), secret+(16*i), seed);
3635
}
3636
acc = XXH3_avalanche(acc);
3637
XXH_ASSERT(nbRounds >= 8);
3638
#if defined(__clang__) /* Clang */ \
3639
&& (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */ \
3640
&& !defined(XXH_ENABLE_AUTOVECTORIZE) /* Define to disable */
3641
/*
3642
* UGLY HACK:
3643
* Clang for ARMv7-A tries to vectorize this loop, similar to GCC x86.
3644
* In everywhere else, it uses scalar code.
3645
*
3646
* For 64->128-bit multiplies, even if the NEON was 100% optimal, it
3647
* would still be slower than UMAAL (see XXH_mult64to128).
3648
*
3649
* Unfortunately, Clang doesn't handle the long multiplies properly and
3650
* converts them to the nonexistent "vmulq_u64" intrinsic, which is then
3651
* scalarized into an ugly mess of VMOV.32 instructions.
3652
*
3653
* This mess is difficult to avoid without turning autovectorization
3654
* off completely, but they are usually relatively minor and/or not
3655
* worth it to fix.
3656
*
3657
* This loop is the easiest to fix, as unlike XXH32, this pragma
3658
* _actually works_ because it is a loop vectorization instead of an
3659
* SLP vectorization.
3660
*/
3661
#pragma clang loop vectorize(disable)
3662
#endif
3663
for (i=8 ; i < nbRounds; i++) {
3664
acc += XXH3_mix16B(input+(16*i), secret+(16*(i-8)) + XXH3_MIDSIZE_STARTOFFSET, seed);
3665
}
3666
/* last bytes */
3667
acc += XXH3_mix16B(input + len - 16, secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET, seed);
3668
return XXH3_avalanche(acc);
3669
}
3670
}
3671
3672
3673
/* ======= Long Keys ======= */
3674
3675
#define XXH_STRIPE_LEN 64
3676
#define XXH_SECRET_CONSUME_RATE 8 /* nb of secret bytes consumed at each accumulation */
3677
#define XXH_ACC_NB (XXH_STRIPE_LEN / sizeof(xxh_u64))
3678
3679
#ifdef XXH_OLD_NAMES
3680
# define STRIPE_LEN XXH_STRIPE_LEN
3681
# define ACC_NB XXH_ACC_NB
3682
#endif
3683
3684
XXH_FORCE_INLINE void XXH_writeLE64(void* dst, xxh_u64 v64)
3685
{
3686
if (!XXH_CPU_LITTLE_ENDIAN) v64 = XXH_swap64(v64);
3687
XXH_memcpy(dst, &v64, sizeof(v64));
3688
}
3689
3690
/* Several intrinsic functions below are supposed to accept __int64 as argument,
3691
* as documented in https://software.intel.com/sites/landingpage/IntrinsicsGuide/ .
3692
* However, several environments do not define __int64 type,
3693
* requiring a workaround.
3694
*/
3695
#if !defined (__VMS) \
3696
&& (defined (__cplusplus) \
3697
|| (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
3698
typedef int64_t xxh_i64;
3699
#else
3700
/* the following type must have a width of 64-bit */
3701
typedef long long xxh_i64;
3702
#endif
3703
3704
3705
/*
3706
* XXH3_accumulate_512 is the tightest loop for long inputs, and it is the most optimized.
3707
*
3708
* It is a hardened version of UMAC, based off of FARSH's implementation.
3709
*
3710
* This was chosen because it adapts quite well to 32-bit, 64-bit, and SIMD
3711
* implementations, and it is ridiculously fast.
3712
*
3713
* We harden it by mixing the original input to the accumulators as well as the product.
3714
*
3715
* This means that in the (relatively likely) case of a multiply by zero, the
3716
* original input is preserved.
3717
*
3718
* On 128-bit inputs, we swap 64-bit pairs when we add the input to improve
3719
* cross-pollination, as otherwise the upper and lower halves would be
3720
* essentially independent.
3721
*
3722
* This doesn't matter on 64-bit hashes since they all get merged together in
3723
* the end, so we skip the extra step.
3724
*
3725
* Both XXH3_64bits and XXH3_128bits use this subroutine.
3726
*/
3727
3728
#if (XXH_VECTOR == XXH_AVX512) \
3729
|| (defined(XXH_DISPATCH_AVX512) && XXH_DISPATCH_AVX512 != 0)
3730
3731
#ifndef XXH_TARGET_AVX512
3732
# define XXH_TARGET_AVX512 /* disable attribute target */
3733
#endif
3734
3735
XXH_FORCE_INLINE XXH_TARGET_AVX512 void
3736
XXH3_accumulate_512_avx512(void* XXH_RESTRICT acc,
3737
const void* XXH_RESTRICT input,
3738
const void* XXH_RESTRICT secret)
3739
{
3740
__m512i* const xacc = (__m512i *) acc;
3741
XXH_ASSERT((((size_t)acc) & 63) == 0);
3742
XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));
3743
3744
{
3745
/* data_vec = input[0]; */
3746
__m512i const data_vec = _mm512_loadu_si512 (input);
3747
/* key_vec = secret[0]; */
3748
__m512i const key_vec = _mm512_loadu_si512 (secret);
3749
/* data_key = data_vec ^ key_vec; */
3750
__m512i const data_key = _mm512_xor_si512 (data_vec, key_vec);
3751
/* data_key_lo = data_key >> 32; */
3752
__m512i const data_key_lo = _mm512_shuffle_epi32 (data_key, (_MM_PERM_ENUM)_MM_SHUFFLE(0, 3, 0, 1));
3753
/* product = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
3754
__m512i const product = _mm512_mul_epu32 (data_key, data_key_lo);
3755
/* xacc[0] += swap(data_vec); */
3756
__m512i const data_swap = _mm512_shuffle_epi32(data_vec, (_MM_PERM_ENUM)_MM_SHUFFLE(1, 0, 3, 2));
3757
__m512i const sum = _mm512_add_epi64(*xacc, data_swap);
3758
/* xacc[0] += product; */
3759
*xacc = _mm512_add_epi64(product, sum);
3760
}
3761
}
3762
3763
/*
3764
* XXH3_scrambleAcc: Scrambles the accumulators to improve mixing.
3765
*
3766
* Multiplication isn't perfect, as explained by Google in HighwayHash:
3767
*
3768
* // Multiplication mixes/scrambles bytes 0-7 of the 64-bit result to
3769
* // varying degrees. In descending order of goodness, bytes
3770
* // 3 4 2 5 1 6 0 7 have quality 228 224 164 160 100 96 36 32.
3771
* // As expected, the upper and lower bytes are much worse.
3772
*
3773
* Source: https://github.com/google/highwayhash/blob/0aaf66b/highwayhash/hh_avx2.h#L291
3774
*
3775
* Since our algorithm uses a pseudorandom secret to add some variance into the
3776
* mix, we don't need to (or want to) mix as often or as much as HighwayHash does.
3777
*
3778
* This isn't as tight as XXH3_accumulate, but still written in SIMD to avoid
3779
* extraction.
3780
*
3781
* Both XXH3_64bits and XXH3_128bits use this subroutine.
3782
*/
3783
3784
XXH_FORCE_INLINE XXH_TARGET_AVX512 void
3785
XXH3_scrambleAcc_avx512(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
3786
{
3787
XXH_ASSERT((((size_t)acc) & 63) == 0);
3788
XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));
3789
{ __m512i* const xacc = (__m512i*) acc;
3790
const __m512i prime32 = _mm512_set1_epi32((int)XXH_PRIME32_1);
3791
3792
/* xacc[0] ^= (xacc[0] >> 47) */
3793
__m512i const acc_vec = *xacc;
3794
__m512i const shifted = _mm512_srli_epi64 (acc_vec, 47);
3795
__m512i const data_vec = _mm512_xor_si512 (acc_vec, shifted);
3796
/* xacc[0] ^= secret; */
3797
__m512i const key_vec = _mm512_loadu_si512 (secret);
3798
__m512i const data_key = _mm512_xor_si512 (data_vec, key_vec);
3799
3800
/* xacc[0] *= XXH_PRIME32_1; */
3801
__m512i const data_key_hi = _mm512_shuffle_epi32 (data_key, (_MM_PERM_ENUM)_MM_SHUFFLE(0, 3, 0, 1));
3802
__m512i const prod_lo = _mm512_mul_epu32 (data_key, prime32);
3803
__m512i const prod_hi = _mm512_mul_epu32 (data_key_hi, prime32);
3804
*xacc = _mm512_add_epi64(prod_lo, _mm512_slli_epi64(prod_hi, 32));
3805
}
3806
}
3807
3808
XXH_FORCE_INLINE XXH_TARGET_AVX512 void
3809
XXH3_initCustomSecret_avx512(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
3810
{
3811
XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 63) == 0);
3812
XXH_STATIC_ASSERT(XXH_SEC_ALIGN == 64);
3813
XXH_ASSERT(((size_t)customSecret & 63) == 0);
3814
(void)(&XXH_writeLE64);
3815
{ int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m512i);
3816
__m512i const seed = _mm512_mask_set1_epi64(_mm512_set1_epi64((xxh_i64)seed64), 0xAA, (xxh_i64)(0U - seed64));
3817
3818
const __m512i* const src = (const __m512i*) ((const void*) XXH3_kSecret);
3819
__m512i* const dest = ( __m512i*) customSecret;
3820
int i;
3821
XXH_ASSERT(((size_t)src & 63) == 0); /* control alignment */
3822
XXH_ASSERT(((size_t)dest & 63) == 0);
3823
for (i=0; i < nbRounds; ++i) {
3824
/* GCC has a bug, _mm512_stream_load_si512 accepts 'void*', not 'void const*',
3825
* this will warn "discards 'const' qualifier". */
3826
union {
3827
const __m512i* cp;
3828
void* p;
3829
} remote_const_void;
3830
remote_const_void.cp = src + i;
3831
dest[i] = _mm512_add_epi64(_mm512_stream_load_si512(remote_const_void.p), seed);
3832
} }
3833
}
3834
3835
#endif
3836
3837
#if (XXH_VECTOR == XXH_AVX2) \
3838
|| (defined(XXH_DISPATCH_AVX2) && XXH_DISPATCH_AVX2 != 0)
3839
3840
#ifndef XXH_TARGET_AVX2
3841
# define XXH_TARGET_AVX2 /* disable attribute target */
3842
#endif
3843
3844
XXH_FORCE_INLINE XXH_TARGET_AVX2 void
3845
XXH3_accumulate_512_avx2( void* XXH_RESTRICT acc,
3846
const void* XXH_RESTRICT input,
3847
const void* XXH_RESTRICT secret)
3848
{
3849
XXH_ASSERT((((size_t)acc) & 31) == 0);
3850
{ __m256i* const xacc = (__m256i *) acc;
3851
/* Unaligned. This is mainly for pointer arithmetic, and because
3852
* _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
3853
const __m256i* const xinput = (const __m256i *) input;
3854
/* Unaligned. This is mainly for pointer arithmetic, and because
3855
* _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
3856
const __m256i* const xsecret = (const __m256i *) secret;
3857
3858
size_t i;
3859
for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
3860
/* data_vec = xinput[i]; */
3861
__m256i const data_vec = _mm256_loadu_si256 (xinput+i);
3862
/* key_vec = xsecret[i]; */
3863
__m256i const key_vec = _mm256_loadu_si256 (xsecret+i);
3864
/* data_key = data_vec ^ key_vec; */
3865
__m256i const data_key = _mm256_xor_si256 (data_vec, key_vec);
3866
/* data_key_lo = data_key >> 32; */
3867
__m256i const data_key_lo = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
3868
/* product = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
3869
__m256i const product = _mm256_mul_epu32 (data_key, data_key_lo);
3870
/* xacc[i] += swap(data_vec); */
3871
__m256i const data_swap = _mm256_shuffle_epi32(data_vec, _MM_SHUFFLE(1, 0, 3, 2));
3872
__m256i const sum = _mm256_add_epi64(xacc[i], data_swap);
3873
/* xacc[i] += product; */
3874
xacc[i] = _mm256_add_epi64(product, sum);
3875
} }
3876
}
3877
3878
XXH_FORCE_INLINE XXH_TARGET_AVX2 void
3879
XXH3_scrambleAcc_avx2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
3880
{
3881
XXH_ASSERT((((size_t)acc) & 31) == 0);
3882
{ __m256i* const xacc = (__m256i*) acc;
3883
/* Unaligned. This is mainly for pointer arithmetic, and because
3884
* _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
3885
const __m256i* const xsecret = (const __m256i *) secret;
3886
const __m256i prime32 = _mm256_set1_epi32((int)XXH_PRIME32_1);
3887
3888
size_t i;
3889
for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
3890
/* xacc[i] ^= (xacc[i] >> 47) */
3891
__m256i const acc_vec = xacc[i];
3892
__m256i const shifted = _mm256_srli_epi64 (acc_vec, 47);
3893
__m256i const data_vec = _mm256_xor_si256 (acc_vec, shifted);
3894
/* xacc[i] ^= xsecret; */
3895
__m256i const key_vec = _mm256_loadu_si256 (xsecret+i);
3896
__m256i const data_key = _mm256_xor_si256 (data_vec, key_vec);
3897
3898
/* xacc[i] *= XXH_PRIME32_1; */
3899
__m256i const data_key_hi = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
3900
__m256i const prod_lo = _mm256_mul_epu32 (data_key, prime32);
3901
__m256i const prod_hi = _mm256_mul_epu32 (data_key_hi, prime32);
3902
xacc[i] = _mm256_add_epi64(prod_lo, _mm256_slli_epi64(prod_hi, 32));
3903
}
3904
}
3905
}
3906
3907
XXH_FORCE_INLINE XXH_TARGET_AVX2 void XXH3_initCustomSecret_avx2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
3908
{
3909
XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 31) == 0);
3910
XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE / sizeof(__m256i)) == 6);
3911
XXH_STATIC_ASSERT(XXH_SEC_ALIGN <= 64);
3912
(void)(&XXH_writeLE64);
3913
XXH_PREFETCH(customSecret);
3914
{ __m256i const seed = _mm256_set_epi64x((xxh_i64)(0U - seed64), (xxh_i64)seed64, (xxh_i64)(0U - seed64), (xxh_i64)seed64);
3915
3916
const __m256i* const src = (const __m256i*) ((const void*) XXH3_kSecret);
3917
__m256i* dest = ( __m256i*) customSecret;
3918
3919
# if defined(__GNUC__) || defined(__clang__)
3920
/*
3921
* On GCC & Clang, marking 'dest' as modified will cause the compiler:
3922
* - do not extract the secret from sse registers in the internal loop
3923
* - use less common registers, and avoid pushing these reg into stack
3924
*/
3925
XXH_COMPILER_GUARD(dest);
3926
# endif
3927
XXH_ASSERT(((size_t)src & 31) == 0); /* control alignment */
3928
XXH_ASSERT(((size_t)dest & 31) == 0);
3929
3930
/* GCC -O2 need unroll loop manually */
3931
dest[0] = _mm256_add_epi64(_mm256_stream_load_si256(src+0), seed);
3932
dest[1] = _mm256_add_epi64(_mm256_stream_load_si256(src+1), seed);
3933
dest[2] = _mm256_add_epi64(_mm256_stream_load_si256(src+2), seed);
3934
dest[3] = _mm256_add_epi64(_mm256_stream_load_si256(src+3), seed);
3935
dest[4] = _mm256_add_epi64(_mm256_stream_load_si256(src+4), seed);
3936
dest[5] = _mm256_add_epi64(_mm256_stream_load_si256(src+5), seed);
3937
}
3938
}
3939
3940
#endif
3941
3942
/* x86dispatch always generates SSE2 */
3943
#if (XXH_VECTOR == XXH_SSE2) || defined(XXH_X86DISPATCH)
3944
3945
#ifndef XXH_TARGET_SSE2
3946
# define XXH_TARGET_SSE2 /* disable attribute target */
3947
#endif
3948
3949
XXH_FORCE_INLINE XXH_TARGET_SSE2 void
3950
XXH3_accumulate_512_sse2( void* XXH_RESTRICT acc,
3951
const void* XXH_RESTRICT input,
3952
const void* XXH_RESTRICT secret)
3953
{
3954
/* SSE2 is just a half-scale version of the AVX2 version. */
3955
XXH_ASSERT((((size_t)acc) & 15) == 0);
3956
{ __m128i* const xacc = (__m128i *) acc;
3957
/* Unaligned. This is mainly for pointer arithmetic, and because
3958
* _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
3959
const __m128i* const xinput = (const __m128i *) input;
3960
/* Unaligned. This is mainly for pointer arithmetic, and because
3961
* _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
3962
const __m128i* const xsecret = (const __m128i *) secret;
3963
3964
size_t i;
3965
for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
3966
/* data_vec = xinput[i]; */
3967
__m128i const data_vec = _mm_loadu_si128 (xinput+i);
3968
/* key_vec = xsecret[i]; */
3969
__m128i const key_vec = _mm_loadu_si128 (xsecret+i);
3970
/* data_key = data_vec ^ key_vec; */
3971
__m128i const data_key = _mm_xor_si128 (data_vec, key_vec);
3972
/* data_key_lo = data_key >> 32; */
3973
__m128i const data_key_lo = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
3974
/* product = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
3975
__m128i const product = _mm_mul_epu32 (data_key, data_key_lo);
3976
/* xacc[i] += swap(data_vec); */
3977
__m128i const data_swap = _mm_shuffle_epi32(data_vec, _MM_SHUFFLE(1,0,3,2));
3978
__m128i const sum = _mm_add_epi64(xacc[i], data_swap);
3979
/* xacc[i] += product; */
3980
xacc[i] = _mm_add_epi64(product, sum);
3981
} }
3982
}
3983
3984
XXH_FORCE_INLINE XXH_TARGET_SSE2 void
3985
XXH3_scrambleAcc_sse2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
3986
{
3987
XXH_ASSERT((((size_t)acc) & 15) == 0);
3988
{ __m128i* const xacc = (__m128i*) acc;
3989
/* Unaligned. This is mainly for pointer arithmetic, and because
3990
* _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
3991
const __m128i* const xsecret = (const __m128i *) secret;
3992
const __m128i prime32 = _mm_set1_epi32((int)XXH_PRIME32_1);
3993
3994
size_t i;
3995
for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
3996
/* xacc[i] ^= (xacc[i] >> 47) */
3997
__m128i const acc_vec = xacc[i];
3998
__m128i const shifted = _mm_srli_epi64 (acc_vec, 47);
3999
__m128i const data_vec = _mm_xor_si128 (acc_vec, shifted);
4000
/* xacc[i] ^= xsecret[i]; */
4001
__m128i const key_vec = _mm_loadu_si128 (xsecret+i);
4002
__m128i const data_key = _mm_xor_si128 (data_vec, key_vec);
4003
4004
/* xacc[i] *= XXH_PRIME32_1; */
4005
__m128i const data_key_hi = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
4006
__m128i const prod_lo = _mm_mul_epu32 (data_key, prime32);
4007
__m128i const prod_hi = _mm_mul_epu32 (data_key_hi, prime32);
4008
xacc[i] = _mm_add_epi64(prod_lo, _mm_slli_epi64(prod_hi, 32));
4009
}
4010
}
4011
}
4012
4013
XXH_FORCE_INLINE XXH_TARGET_SSE2 void XXH3_initCustomSecret_sse2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
4014
{
4015
XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
4016
(void)(&XXH_writeLE64);
4017
{ int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m128i);
4018
4019
# if defined(_MSC_VER) && defined(_M_IX86) && _MSC_VER < 1900
4020
/* MSVC 32bit mode does not support _mm_set_epi64x before 2015 */
4021
XXH_ALIGN(16) const xxh_i64 seed64x2[2] = { (xxh_i64)seed64, (xxh_i64)(0U - seed64) };
4022
__m128i const seed = _mm_load_si128((__m128i const*)seed64x2);
4023
# else
4024
__m128i const seed = _mm_set_epi64x((xxh_i64)(0U - seed64), (xxh_i64)seed64);
4025
# endif
4026
int i;
4027
4028
const void* const src16 = XXH3_kSecret;
4029
__m128i* dst16 = (__m128i*) customSecret;
4030
# if defined(__GNUC__) || defined(__clang__)
4031
/*
4032
* On GCC & Clang, marking 'dest' as modified will cause the compiler:
4033
* - do not extract the secret from sse registers in the internal loop
4034
* - use less common registers, and avoid pushing these reg into stack
4035
*/
4036
XXH_COMPILER_GUARD(dst16);
4037
# endif
4038
XXH_ASSERT(((size_t)src16 & 15) == 0); /* control alignment */
4039
XXH_ASSERT(((size_t)dst16 & 15) == 0);
4040
4041
for (i=0; i < nbRounds; ++i) {
4042
dst16[i] = _mm_add_epi64(_mm_load_si128((const __m128i *)src16+i), seed);
4043
} }
4044
}
4045
4046
#endif
4047
4048
#if (XXH_VECTOR == XXH_NEON)
4049
4050
/* forward declarations for the scalar routines */
4051
XXH_FORCE_INLINE void
4052
XXH3_scalarRound(void* XXH_RESTRICT acc, void const* XXH_RESTRICT input,
4053
void const* XXH_RESTRICT secret, size_t lane);
4054
4055
XXH_FORCE_INLINE void
4056
XXH3_scalarScrambleRound(void* XXH_RESTRICT acc,
4057
void const* XXH_RESTRICT secret, size_t lane);
4058
4059
/*!
4060
* @internal
4061
* @brief The bulk processing loop for NEON.
4062
*
4063
* The NEON code path is actually partially scalar when running on AArch64. This
4064
* is to optimize the pipelining and can have up to 15% speedup depending on the
4065
* CPU, and it also mitigates some GCC codegen issues.
4066
*
4067
* @see XXH3_NEON_LANES for configuring this and details about this optimization.
4068
*/
4069
XXH_FORCE_INLINE void
4070
XXH3_accumulate_512_neon( void* XXH_RESTRICT acc,
4071
const void* XXH_RESTRICT input,
4072
const void* XXH_RESTRICT secret)
4073
{
4074
XXH_ASSERT((((size_t)acc) & 15) == 0);
4075
XXH_STATIC_ASSERT(XXH3_NEON_LANES > 0 && XXH3_NEON_LANES <= XXH_ACC_NB && XXH3_NEON_LANES % 2 == 0);
4076
{
4077
uint64x2_t* const xacc = (uint64x2_t *) acc;
4078
/* We don't use a uint32x4_t pointer because it causes bus errors on ARMv7. */
4079
uint8_t const* const xinput = (const uint8_t *) input;
4080
uint8_t const* const xsecret = (const uint8_t *) secret;
4081
4082
size_t i;
4083
/* NEON for the first few lanes (these loops are normally interleaved) */
4084
for (i=0; i < XXH3_NEON_LANES / 2; i++) {
4085
/* data_vec = xinput[i]; */
4086
uint8x16_t data_vec = vld1q_u8(xinput + (i * 16));
4087
/* key_vec = xsecret[i]; */
4088
uint8x16_t key_vec = vld1q_u8(xsecret + (i * 16));
4089
uint64x2_t data_key;
4090
uint32x2_t data_key_lo, data_key_hi;
4091
/* xacc[i] += swap(data_vec); */
4092
uint64x2_t const data64 = vreinterpretq_u64_u8(data_vec);
4093
uint64x2_t const swapped = vextq_u64(data64, data64, 1);
4094
xacc[i] = vaddq_u64 (xacc[i], swapped);
4095
/* data_key = data_vec ^ key_vec; */
4096
data_key = vreinterpretq_u64_u8(veorq_u8(data_vec, key_vec));
4097
/* data_key_lo = (uint32x2_t) (data_key & 0xFFFFFFFF);
4098
* data_key_hi = (uint32x2_t) (data_key >> 32);
4099
* data_key = UNDEFINED; */
4100
XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
4101
/* xacc[i] += (uint64x2_t) data_key_lo * (uint64x2_t) data_key_hi; */
4102
xacc[i] = vmlal_u32 (xacc[i], data_key_lo, data_key_hi);
4103
4104
}
4105
/* Scalar for the remainder. This may be a zero iteration loop. */
4106
for (i = XXH3_NEON_LANES; i < XXH_ACC_NB; i++) {
4107
XXH3_scalarRound(acc, input, secret, i);
4108
}
4109
}
4110
}
4111
4112
XXH_FORCE_INLINE void
4113
XXH3_scrambleAcc_neon(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
4114
{
4115
XXH_ASSERT((((size_t)acc) & 15) == 0);
4116
4117
{ uint64x2_t* xacc = (uint64x2_t*) acc;
4118
uint8_t const* xsecret = (uint8_t const*) secret;
4119
uint32x2_t prime = vdup_n_u32 (XXH_PRIME32_1);
4120
4121
size_t i;
4122
/* NEON for the first few lanes (these loops are normally interleaved) */
4123
for (i=0; i < XXH3_NEON_LANES / 2; i++) {
4124
/* xacc[i] ^= (xacc[i] >> 47); */
4125
uint64x2_t acc_vec = xacc[i];
4126
uint64x2_t shifted = vshrq_n_u64 (acc_vec, 47);
4127
uint64x2_t data_vec = veorq_u64 (acc_vec, shifted);
4128
4129
/* xacc[i] ^= xsecret[i]; */
4130
uint8x16_t key_vec = vld1q_u8 (xsecret + (i * 16));
4131
uint64x2_t data_key = veorq_u64 (data_vec, vreinterpretq_u64_u8(key_vec));
4132
4133
/* xacc[i] *= XXH_PRIME32_1 */
4134
uint32x2_t data_key_lo, data_key_hi;
4135
/* data_key_lo = (uint32x2_t) (xacc[i] & 0xFFFFFFFF);
4136
* data_key_hi = (uint32x2_t) (xacc[i] >> 32);
4137
* xacc[i] = UNDEFINED; */
4138
XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
4139
{ /*
4140
* prod_hi = (data_key >> 32) * XXH_PRIME32_1;
4141
*
4142
* Avoid vmul_u32 + vshll_n_u32 since Clang 6 and 7 will
4143
* incorrectly "optimize" this:
4144
* tmp = vmul_u32(vmovn_u64(a), vmovn_u64(b));
4145
* shifted = vshll_n_u32(tmp, 32);
4146
* to this:
4147
* tmp = "vmulq_u64"(a, b); // no such thing!
4148
* shifted = vshlq_n_u64(tmp, 32);
4149
*
4150
* However, unlike SSE, Clang lacks a 64-bit multiply routine
4151
* for NEON, and it scalarizes two 64-bit multiplies instead.
4152
*
4153
* vmull_u32 has the same timing as vmul_u32, and it avoids
4154
* this bug completely.
4155
* See https://bugs.llvm.org/show_bug.cgi?id=39967
4156
*/
4157
uint64x2_t prod_hi = vmull_u32 (data_key_hi, prime);
4158
/* xacc[i] = prod_hi << 32; */
4159
xacc[i] = vshlq_n_u64(prod_hi, 32);
4160
/* xacc[i] += (prod_hi & 0xFFFFFFFF) * XXH_PRIME32_1; */
4161
xacc[i] = vmlal_u32(xacc[i], data_key_lo, prime);
4162
}
4163
}
4164
/* Scalar for the remainder. This may be a zero iteration loop. */
4165
for (i = XXH3_NEON_LANES; i < XXH_ACC_NB; i++) {
4166
XXH3_scalarScrambleRound(acc, secret, i);
4167
}
4168
}
4169
}
4170
4171
#endif
4172
4173
#if (XXH_VECTOR == XXH_VSX)
4174
4175
XXH_FORCE_INLINE void
4176
XXH3_accumulate_512_vsx( void* XXH_RESTRICT acc,
4177
const void* XXH_RESTRICT input,
4178
const void* XXH_RESTRICT secret)
4179
{
4180
/* presumed aligned */
4181
unsigned int* const xacc = (unsigned int*) acc;
4182
xxh_u64x2 const* const xinput = (xxh_u64x2 const*) input; /* no alignment restriction */
4183
xxh_u64x2 const* const xsecret = (xxh_u64x2 const*) secret; /* no alignment restriction */
4184
xxh_u64x2 const v32 = { 32, 32 };
4185
size_t i;
4186
for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
4187
/* data_vec = xinput[i]; */
4188
xxh_u64x2 const data_vec = XXH_vec_loadu(xinput + i);
4189
/* key_vec = xsecret[i]; */
4190
xxh_u64x2 const key_vec = XXH_vec_loadu(xsecret + i);
4191
xxh_u64x2 const data_key = data_vec ^ key_vec;
4192
/* shuffled = (data_key << 32) | (data_key >> 32); */
4193
xxh_u32x4 const shuffled = (xxh_u32x4)vec_rl(data_key, v32);
4194
/* product = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)shuffled & 0xFFFFFFFF); */
4195
xxh_u64x2 const product = XXH_vec_mulo((xxh_u32x4)data_key, shuffled);
4196
/* acc_vec = xacc[i]; */
4197
xxh_u64x2 acc_vec = (xxh_u64x2)vec_xl(0, xacc + 4 * i);
4198
acc_vec += product;
4199
4200
/* swap high and low halves */
4201
#ifdef __s390x__
4202
acc_vec += vec_permi(data_vec, data_vec, 2);
4203
#else
4204
acc_vec += vec_xxpermdi(data_vec, data_vec, 2);
4205
#endif
4206
/* xacc[i] = acc_vec; */
4207
vec_xst((xxh_u32x4)acc_vec, 0, xacc + 4 * i);
4208
}
4209
}
4210
4211
XXH_FORCE_INLINE void
4212
XXH3_scrambleAcc_vsx(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
4213
{
4214
XXH_ASSERT((((size_t)acc) & 15) == 0);
4215
4216
{ xxh_u64x2* const xacc = (xxh_u64x2*) acc;
4217
const xxh_u64x2* const xsecret = (const xxh_u64x2*) secret;
4218
/* constants */
4219
xxh_u64x2 const v32 = { 32, 32 };
4220
xxh_u64x2 const v47 = { 47, 47 };
4221
xxh_u32x4 const prime = { XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1 };
4222
size_t i;
4223
for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
4224
/* xacc[i] ^= (xacc[i] >> 47); */
4225
xxh_u64x2 const acc_vec = xacc[i];
4226
xxh_u64x2 const data_vec = acc_vec ^ (acc_vec >> v47);
4227
4228
/* xacc[i] ^= xsecret[i]; */
4229
xxh_u64x2 const key_vec = XXH_vec_loadu(xsecret + i);
4230
xxh_u64x2 const data_key = data_vec ^ key_vec;
4231
4232
/* xacc[i] *= XXH_PRIME32_1 */
4233
/* prod_lo = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)prime & 0xFFFFFFFF); */
4234
xxh_u64x2 const prod_even = XXH_vec_mule((xxh_u32x4)data_key, prime);
4235
/* prod_hi = ((xxh_u64x2)data_key >> 32) * ((xxh_u64x2)prime >> 32); */
4236
xxh_u64x2 const prod_odd = XXH_vec_mulo((xxh_u32x4)data_key, prime);
4237
xacc[i] = prod_odd + (prod_even << v32);
4238
} }
4239
}
4240
4241
#endif
4242
4243
/* scalar variants - universal */
4244
4245
/*!
4246
* @internal
4247
* @brief Scalar round for @ref XXH3_accumulate_512_scalar().
4248
*
4249
* This is extracted to its own function because the NEON path uses a combination
4250
* of NEON and scalar.
4251
*/
4252
XXH_FORCE_INLINE void
4253
XXH3_scalarRound(void* XXH_RESTRICT acc,
4254
void const* XXH_RESTRICT input,
4255
void const* XXH_RESTRICT secret,
4256
size_t lane)
4257
{
4258
xxh_u64* xacc = (xxh_u64*) acc;
4259
xxh_u8 const* xinput = (xxh_u8 const*) input;
4260
xxh_u8 const* xsecret = (xxh_u8 const*) secret;
4261
XXH_ASSERT(lane < XXH_ACC_NB);
4262
XXH_ASSERT(((size_t)acc & (XXH_ACC_ALIGN-1)) == 0);
4263
{
4264
xxh_u64 const data_val = XXH_readLE64(xinput + lane * 8);
4265
xxh_u64 const data_key = data_val ^ XXH_readLE64(xsecret + lane * 8);
4266
xacc[lane ^ 1] += data_val; /* swap adjacent lanes */
4267
xacc[lane] += XXH_mult32to64(data_key & 0xFFFFFFFF, data_key >> 32);
4268
}
4269
}
4270
4271
/*!
4272
* @internal
4273
* @brief Processes a 64 byte block of data using the scalar path.
4274
*/
4275
XXH_FORCE_INLINE void
4276
XXH3_accumulate_512_scalar(void* XXH_RESTRICT acc,
4277
const void* XXH_RESTRICT input,
4278
const void* XXH_RESTRICT secret)
4279
{
4280
size_t i;
4281
for (i=0; i < XXH_ACC_NB; i++) {
4282
XXH3_scalarRound(acc, input, secret, i);
4283
}
4284
}
4285
4286
/*!
4287
* @internal
4288
* @brief Scalar scramble step for @ref XXH3_scrambleAcc_scalar().
4289
*
4290
* This is extracted to its own function because the NEON path uses a combination
4291
* of NEON and scalar.
4292
*/
4293
XXH_FORCE_INLINE void
4294
XXH3_scalarScrambleRound(void* XXH_RESTRICT acc,
4295
void const* XXH_RESTRICT secret,
4296
size_t lane)
4297
{
4298
xxh_u64* const xacc = (xxh_u64*) acc; /* presumed aligned */
4299
const xxh_u8* const xsecret = (const xxh_u8*) secret; /* no alignment restriction */
4300
XXH_ASSERT((((size_t)acc) & (XXH_ACC_ALIGN-1)) == 0);
4301
XXH_ASSERT(lane < XXH_ACC_NB);
4302
{
4303
xxh_u64 const key64 = XXH_readLE64(xsecret + lane * 8);
4304
xxh_u64 acc64 = xacc[lane];
4305
acc64 = XXH_xorshift64(acc64, 47);
4306
acc64 ^= key64;
4307
acc64 *= XXH_PRIME32_1;
4308
xacc[lane] = acc64;
4309
}
4310
}
4311
4312
/*!
4313
* @internal
4314
* @brief Scrambles the accumulators after a large chunk has been read
4315
*/
4316
XXH_FORCE_INLINE void
4317
XXH3_scrambleAcc_scalar(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
4318
{
4319
size_t i;
4320
for (i=0; i < XXH_ACC_NB; i++) {
4321
XXH3_scalarScrambleRound(acc, secret, i);
4322
}
4323
}
4324
4325
XXH_FORCE_INLINE void
4326
XXH3_initCustomSecret_scalar(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
4327
{
4328
/*
4329
* We need a separate pointer for the hack below,
4330
* which requires a non-const pointer.
4331
* Any decent compiler will optimize this out otherwise.
4332
*/
4333
const xxh_u8* kSecretPtr = XXH3_kSecret;
4334
XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
4335
4336
#if defined(__clang__) && defined(__aarch64__)
4337
/*
4338
* UGLY HACK:
4339
* Clang generates a bunch of MOV/MOVK pairs for aarch64, and they are
4340
* placed sequentially, in order, at the top of the unrolled loop.
4341
*
4342
* While MOVK is great for generating constants (2 cycles for a 64-bit
4343
* constant compared to 4 cycles for LDR), it fights for bandwidth with
4344
* the arithmetic instructions.
4345
*
4346
* I L S
4347
* MOVK
4348
* MOVK
4349
* MOVK
4350
* MOVK
4351
* ADD
4352
* SUB STR
4353
* STR
4354
* By forcing loads from memory (as the asm line causes Clang to assume
4355
* that XXH3_kSecretPtr has been changed), the pipelines are used more
4356
* efficiently:
4357
* I L S
4358
* LDR
4359
* ADD LDR
4360
* SUB STR
4361
* STR
4362
*
4363
* See XXH3_NEON_LANES for details on the pipsline.
4364
*
4365
* XXH3_64bits_withSeed, len == 256, Snapdragon 835
4366
* without hack: 2654.4 MB/s
4367
* with hack: 3202.9 MB/s
4368
*/
4369
XXH_COMPILER_GUARD(kSecretPtr);
4370
#endif
4371
/*
4372
* Note: in debug mode, this overrides the asm optimization
4373
* and Clang will emit MOVK chains again.
4374
*/
4375
XXH_ASSERT(kSecretPtr == XXH3_kSecret);
4376
4377
{ int const nbRounds = XXH_SECRET_DEFAULT_SIZE / 16;
4378
int i;
4379
for (i=0; i < nbRounds; i++) {
4380
/*
4381
* The asm hack causes Clang to assume that kSecretPtr aliases with
4382
* customSecret, and on aarch64, this prevented LDP from merging two
4383
* loads together for free. Putting the loads together before the stores
4384
* properly generates LDP.
4385
*/
4386
xxh_u64 lo = XXH_readLE64(kSecretPtr + 16*i) + seed64;
4387
xxh_u64 hi = XXH_readLE64(kSecretPtr + 16*i + 8) - seed64;
4388
XXH_writeLE64((xxh_u8*)customSecret + 16*i, lo);
4389
XXH_writeLE64((xxh_u8*)customSecret + 16*i + 8, hi);
4390
} }
4391
}
4392
4393
4394
typedef void (*XXH3_f_accumulate_512)(void* XXH_RESTRICT, const void*, const void*);
4395
typedef void (*XXH3_f_scrambleAcc)(void* XXH_RESTRICT, const void*);
4396
typedef void (*XXH3_f_initCustomSecret)(void* XXH_RESTRICT, xxh_u64);
4397
4398
4399
#if (XXH_VECTOR == XXH_AVX512)
4400
4401
#define XXH3_accumulate_512 XXH3_accumulate_512_avx512
4402
#define XXH3_scrambleAcc XXH3_scrambleAcc_avx512
4403
#define XXH3_initCustomSecret XXH3_initCustomSecret_avx512
4404
4405
#elif (XXH_VECTOR == XXH_AVX2)
4406
4407
#define XXH3_accumulate_512 XXH3_accumulate_512_avx2
4408
#define XXH3_scrambleAcc XXH3_scrambleAcc_avx2
4409
#define XXH3_initCustomSecret XXH3_initCustomSecret_avx2
4410
4411
#elif (XXH_VECTOR == XXH_SSE2)
4412
4413
#define XXH3_accumulate_512 XXH3_accumulate_512_sse2
4414
#define XXH3_scrambleAcc XXH3_scrambleAcc_sse2
4415
#define XXH3_initCustomSecret XXH3_initCustomSecret_sse2
4416
4417
#elif (XXH_VECTOR == XXH_NEON)
4418
4419
#define XXH3_accumulate_512 XXH3_accumulate_512_neon
4420
#define XXH3_scrambleAcc XXH3_scrambleAcc_neon
4421
#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
4422
4423
#elif (XXH_VECTOR == XXH_VSX)
4424
4425
#define XXH3_accumulate_512 XXH3_accumulate_512_vsx
4426
#define XXH3_scrambleAcc XXH3_scrambleAcc_vsx
4427
#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
4428
4429
#else /* scalar */
4430
4431
#define XXH3_accumulate_512 XXH3_accumulate_512_scalar
4432
#define XXH3_scrambleAcc XXH3_scrambleAcc_scalar
4433
#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
4434
4435
#endif
4436
4437
4438
4439
#ifndef XXH_PREFETCH_DIST
4440
# ifdef __clang__
4441
# define XXH_PREFETCH_DIST 320
4442
# else
4443
# if (XXH_VECTOR == XXH_AVX512)
4444
# define XXH_PREFETCH_DIST 512
4445
# else
4446
# define XXH_PREFETCH_DIST 384
4447
# endif
4448
# endif /* __clang__ */
4449
#endif /* XXH_PREFETCH_DIST */
4450
4451
/*
4452
* XXH3_accumulate()
4453
* Loops over XXH3_accumulate_512().
4454
* Assumption: nbStripes will not overflow the secret size
4455
*/
4456
XXH_FORCE_INLINE void
4457
XXH3_accumulate( xxh_u64* XXH_RESTRICT acc,
4458
const xxh_u8* XXH_RESTRICT input,
4459
const xxh_u8* XXH_RESTRICT secret,
4460
size_t nbStripes,
4461
XXH3_f_accumulate_512 f_acc512)
4462
{
4463
size_t n;
4464
for (n = 0; n < nbStripes; n++ ) {
4465
const xxh_u8* const in = input + n*XXH_STRIPE_LEN;
4466
XXH_PREFETCH(in + XXH_PREFETCH_DIST);
4467
f_acc512(acc,
4468
in,
4469
secret + n*XXH_SECRET_CONSUME_RATE);
4470
}
4471
}
4472
4473
XXH_FORCE_INLINE void
4474
XXH3_hashLong_internal_loop(xxh_u64* XXH_RESTRICT acc,
4475
const xxh_u8* XXH_RESTRICT input, size_t len,
4476
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
4477
XXH3_f_accumulate_512 f_acc512,
4478
XXH3_f_scrambleAcc f_scramble)
4479
{
4480
size_t const nbStripesPerBlock = (secretSize - XXH_STRIPE_LEN) / XXH_SECRET_CONSUME_RATE;
4481
size_t const block_len = XXH_STRIPE_LEN * nbStripesPerBlock;
4482
size_t const nb_blocks = (len - 1) / block_len;
4483
4484
size_t n;
4485
4486
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
4487
4488
for (n = 0; n < nb_blocks; n++) {
4489
XXH3_accumulate(acc, input + n*block_len, secret, nbStripesPerBlock, f_acc512);
4490
f_scramble(acc, secret + secretSize - XXH_STRIPE_LEN);
4491
}
4492
4493
/* last partial block */
4494
XXH_ASSERT(len > XXH_STRIPE_LEN);
4495
{ size_t const nbStripes = ((len - 1) - (block_len * nb_blocks)) / XXH_STRIPE_LEN;
4496
XXH_ASSERT(nbStripes <= (secretSize / XXH_SECRET_CONSUME_RATE));
4497
XXH3_accumulate(acc, input + nb_blocks*block_len, secret, nbStripes, f_acc512);
4498
4499
/* last stripe */
4500
{ const xxh_u8* const p = input + len - XXH_STRIPE_LEN;
4501
#define XXH_SECRET_LASTACC_START 7 /* not aligned on 8, last secret is different from acc & scrambler */
4502
f_acc512(acc, p, secret + secretSize - XXH_STRIPE_LEN - XXH_SECRET_LASTACC_START);
4503
} }
4504
}
4505
4506
XXH_FORCE_INLINE xxh_u64
4507
XXH3_mix2Accs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret)
4508
{
4509
return XXH3_mul128_fold64(
4510
acc[0] ^ XXH_readLE64(secret),
4511
acc[1] ^ XXH_readLE64(secret+8) );
4512
}
4513
4514
static XXH64_hash_t
4515
XXH3_mergeAccs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret, xxh_u64 start)
4516
{
4517
xxh_u64 result64 = start;
4518
size_t i = 0;
4519
4520
for (i = 0; i < 4; i++) {
4521
result64 += XXH3_mix2Accs(acc+2*i, secret + 16*i);
4522
#if defined(__clang__) /* Clang */ \
4523
&& (defined(__arm__) || defined(__thumb__)) /* ARMv7 */ \
4524
&& (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */ \
4525
&& !defined(XXH_ENABLE_AUTOVECTORIZE) /* Define to disable */
4526
/*
4527
* UGLY HACK:
4528
* Prevent autovectorization on Clang ARMv7-a. Exact same problem as
4529
* the one in XXH3_len_129to240_64b. Speeds up shorter keys > 240b.
4530
* XXH3_64bits, len == 256, Snapdragon 835:
4531
* without hack: 2063.7 MB/s
4532
* with hack: 2560.7 MB/s
4533
*/
4534
XXH_COMPILER_GUARD(result64);
4535
#endif
4536
}
4537
4538
return XXH3_avalanche(result64);
4539
}
4540
4541
#define XXH3_INIT_ACC { XXH_PRIME32_3, XXH_PRIME64_1, XXH_PRIME64_2, XXH_PRIME64_3, \
4542
XXH_PRIME64_4, XXH_PRIME32_2, XXH_PRIME64_5, XXH_PRIME32_1 }
4543
4544
XXH_FORCE_INLINE XXH64_hash_t
4545
XXH3_hashLong_64b_internal(const void* XXH_RESTRICT input, size_t len,
4546
const void* XXH_RESTRICT secret, size_t secretSize,
4547
XXH3_f_accumulate_512 f_acc512,
4548
XXH3_f_scrambleAcc f_scramble)
4549
{
4550
XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;
4551
4552
XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, f_acc512, f_scramble);
4553
4554
/* converge into final hash */
4555
XXH_STATIC_ASSERT(sizeof(acc) == 64);
4556
/* do not align on 8, so that the secret is different from the accumulator */
4557
#define XXH_SECRET_MERGEACCS_START 11
4558
XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
4559
return XXH3_mergeAccs(acc, (const xxh_u8*)secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)len * XXH_PRIME64_1);
4560
}
4561
4562
/*
4563
* It's important for performance to transmit secret's size (when it's static)
4564
* so that the compiler can properly optimize the vectorized loop.
4565
* This makes a big performance difference for "medium" keys (<1 KB) when using AVX instruction set.
4566
*/
4567
XXH_FORCE_INLINE XXH64_hash_t
4568
XXH3_hashLong_64b_withSecret(const void* XXH_RESTRICT input, size_t len,
4569
XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
4570
{
4571
(void)seed64;
4572
return XXH3_hashLong_64b_internal(input, len, secret, secretLen, XXH3_accumulate_512, XXH3_scrambleAcc);
4573
}
4574
4575
/*
4576
* It's preferable for performance that XXH3_hashLong is not inlined,
4577
* as it results in a smaller function for small data, easier to the instruction cache.
4578
* Note that inside this no_inline function, we do inline the internal loop,
4579
* and provide a statically defined secret size to allow optimization of vector loop.
4580
*/
4581
XXH_NO_INLINE XXH64_hash_t
4582
XXH3_hashLong_64b_default(const void* XXH_RESTRICT input, size_t len,
4583
XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
4584
{
4585
(void)seed64; (void)secret; (void)secretLen;
4586
return XXH3_hashLong_64b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_accumulate_512, XXH3_scrambleAcc);
4587
}
4588
4589
/*
4590
* XXH3_hashLong_64b_withSeed():
4591
* Generate a custom key based on alteration of default XXH3_kSecret with the seed,
4592
* and then use this key for long mode hashing.
4593
*
4594
* This operation is decently fast but nonetheless costs a little bit of time.
4595
* Try to avoid it whenever possible (typically when seed==0).
4596
*
4597
* It's important for performance that XXH3_hashLong is not inlined. Not sure
4598
* why (uop cache maybe?), but the difference is large and easily measurable.
4599
*/
4600
XXH_FORCE_INLINE XXH64_hash_t
4601
XXH3_hashLong_64b_withSeed_internal(const void* input, size_t len,
4602
XXH64_hash_t seed,
4603
XXH3_f_accumulate_512 f_acc512,
4604
XXH3_f_scrambleAcc f_scramble,
4605
XXH3_f_initCustomSecret f_initSec)
4606
{
4607
if (seed == 0)
4608
return XXH3_hashLong_64b_internal(input, len,
4609
XXH3_kSecret, sizeof(XXH3_kSecret),
4610
f_acc512, f_scramble);
4611
{ XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
4612
f_initSec(secret, seed);
4613
return XXH3_hashLong_64b_internal(input, len, secret, sizeof(secret),
4614
f_acc512, f_scramble);
4615
}
4616
}
4617
4618
/*
4619
* It's important for performance that XXH3_hashLong is not inlined.
4620
*/
4621
XXH_NO_INLINE XXH64_hash_t
4622
XXH3_hashLong_64b_withSeed(const void* input, size_t len,
4623
XXH64_hash_t seed, const xxh_u8* secret, size_t secretLen)
4624
{
4625
(void)secret; (void)secretLen;
4626
return XXH3_hashLong_64b_withSeed_internal(input, len, seed,
4627
XXH3_accumulate_512, XXH3_scrambleAcc, XXH3_initCustomSecret);
4628
}
4629
4630
4631
typedef XXH64_hash_t (*XXH3_hashLong64_f)(const void* XXH_RESTRICT, size_t,
4632
XXH64_hash_t, const xxh_u8* XXH_RESTRICT, size_t);
4633
4634
XXH_FORCE_INLINE XXH64_hash_t
4635
XXH3_64bits_internal(const void* XXH_RESTRICT input, size_t len,
4636
XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
4637
XXH3_hashLong64_f f_hashLong)
4638
{
4639
XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
4640
/*
4641
* If an action is to be taken if `secretLen` condition is not respected,
4642
* it should be done here.
4643
* For now, it's a contract pre-condition.
4644
* Adding a check and a branch here would cost performance at every hash.
4645
* Also, note that function signature doesn't offer room to return an error.
4646
*/
4647
if (len <= 16)
4648
return XXH3_len_0to16_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
4649
if (len <= 128)
4650
return XXH3_len_17to128_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
4651
if (len <= XXH3_MIDSIZE_MAX)
4652
return XXH3_len_129to240_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
4653
return f_hashLong(input, len, seed64, (const xxh_u8*)secret, secretLen);
4654
}
4655
4656
4657
/* === Public entry point === */
4658
4659
/*! @ingroup xxh3_family */
4660
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(const void* input, size_t len)
4661
{
4662
return XXH3_64bits_internal(input, len, 0, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_default);
4663
}
4664
4665
/*! @ingroup xxh3_family */
4666
XXH_PUBLIC_API XXH64_hash_t
4667
XXH3_64bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
4668
{
4669
return XXH3_64bits_internal(input, len, 0, secret, secretSize, XXH3_hashLong_64b_withSecret);
4670
}
4671
4672
/*! @ingroup xxh3_family */
4673
XXH_PUBLIC_API XXH64_hash_t
4674
XXH3_64bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
4675
{
4676
return XXH3_64bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_withSeed);
4677
}
4678
4679
XXH_PUBLIC_API XXH64_hash_t
4680
XXH3_64bits_withSecretandSeed(const void* input, size_t len, const void* secret, size_t secretSize, XXH64_hash_t seed)
4681
{
4682
if (len <= XXH3_MIDSIZE_MAX)
4683
return XXH3_64bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), NULL);
4684
return XXH3_hashLong_64b_withSecret(input, len, seed, (const xxh_u8*)secret, secretSize);
4685
}
4686
4687
4688
/* === XXH3 streaming === */
4689
4690
/*
4691
* Malloc's a pointer that is always aligned to align.
4692
*
4693
* This must be freed with `XXH_alignedFree()`.
4694
*
4695
* malloc typically guarantees 16 byte alignment on 64-bit systems and 8 byte
4696
* alignment on 32-bit. This isn't enough for the 32 byte aligned loads in AVX2
4697
* or on 32-bit, the 16 byte aligned loads in SSE2 and NEON.
4698
*
4699
* This underalignment previously caused a rather obvious crash which went
4700
* completely unnoticed due to XXH3_createState() not actually being tested.
4701
* Credit to RedSpah for noticing this bug.
4702
*
4703
* The alignment is done manually: Functions like posix_memalign or _mm_malloc
4704
* are avoided: To maintain portability, we would have to write a fallback
4705
* like this anyways, and besides, testing for the existence of library
4706
* functions without relying on external build tools is impossible.
4707
*
4708
* The method is simple: Overallocate, manually align, and store the offset
4709
* to the original behind the returned pointer.
4710
*
4711
* Align must be a power of 2 and 8 <= align <= 128.
4712
*/
4713
static void* XXH_alignedMalloc(size_t s, size_t align)
4714
{
4715
XXH_ASSERT(align <= 128 && align >= 8); /* range check */
4716
XXH_ASSERT((align & (align-1)) == 0); /* power of 2 */
4717
XXH_ASSERT(s != 0 && s < (s + align)); /* empty/overflow */
4718
{ /* Overallocate to make room for manual realignment and an offset byte */
4719
xxh_u8* base = (xxh_u8*)XXH_malloc(s + align);
4720
if (base != NULL) {
4721
/*
4722
* Get the offset needed to align this pointer.
4723
*
4724
* Even if the returned pointer is aligned, there will always be
4725
* at least one byte to store the offset to the original pointer.
4726
*/
4727
size_t offset = align - ((size_t)base & (align - 1)); /* base % align */
4728
/* Add the offset for the now-aligned pointer */
4729
xxh_u8* ptr = base + offset;
4730
4731
XXH_ASSERT((size_t)ptr % align == 0);
4732
4733
/* Store the offset immediately before the returned pointer. */
4734
ptr[-1] = (xxh_u8)offset;
4735
return ptr;
4736
}
4737
return NULL;
4738
}
4739
}
4740
/*
4741
* Frees an aligned pointer allocated by XXH_alignedMalloc(). Don't pass
4742
* normal malloc'd pointers, XXH_alignedMalloc has a specific data layout.
4743
*/
4744
static void XXH_alignedFree(void* p)
4745
{
4746
if (p != NULL) {
4747
xxh_u8* ptr = (xxh_u8*)p;
4748
/* Get the offset byte we added in XXH_malloc. */
4749
xxh_u8 offset = ptr[-1];
4750
/* Free the original malloc'd pointer */
4751
xxh_u8* base = ptr - offset;
4752
XXH_free(base);
4753
}
4754
}
4755
/*! @ingroup xxh3_family */
4756
XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void)
4757
{
4758
XXH3_state_t* const state = (XXH3_state_t*)XXH_alignedMalloc(sizeof(XXH3_state_t), 64);
4759
if (state==NULL) return NULL;
4760
XXH3_INITSTATE(state);
4761
return state;
4762
}
4763
4764
/*! @ingroup xxh3_family */
4765
XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr)
4766
{
4767
XXH_alignedFree(statePtr);
4768
return XXH_OK;
4769
}
4770
4771
/*! @ingroup xxh3_family */
4772
XXH_PUBLIC_API void
4773
XXH3_copyState(XXH3_state_t* dst_state, const XXH3_state_t* src_state)
4774
{
4775
XXH_memcpy(dst_state, src_state, sizeof(*dst_state));
4776
}
4777
4778
static void
4779
XXH3_reset_internal(XXH3_state_t* statePtr,
4780
XXH64_hash_t seed,
4781
const void* secret, size_t secretSize)
4782
{
4783
size_t const initStart = offsetof(XXH3_state_t, bufferedSize);
4784
size_t const initLength = offsetof(XXH3_state_t, nbStripesPerBlock) - initStart;
4785
XXH_ASSERT(offsetof(XXH3_state_t, nbStripesPerBlock) > initStart);
4786
XXH_ASSERT(statePtr != NULL);
4787
/* set members from bufferedSize to nbStripesPerBlock (excluded) to 0 */
4788
memset((char*)statePtr + initStart, 0, initLength);
4789
statePtr->acc[0] = XXH_PRIME32_3;
4790
statePtr->acc[1] = XXH_PRIME64_1;
4791
statePtr->acc[2] = XXH_PRIME64_2;
4792
statePtr->acc[3] = XXH_PRIME64_3;
4793
statePtr->acc[4] = XXH_PRIME64_4;
4794
statePtr->acc[5] = XXH_PRIME32_2;
4795
statePtr->acc[6] = XXH_PRIME64_5;
4796
statePtr->acc[7] = XXH_PRIME32_1;
4797
statePtr->seed = seed;
4798
statePtr->useSeed = (seed != 0);
4799
statePtr->extSecret = (const unsigned char*)secret;
4800
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
4801
statePtr->secretLimit = secretSize - XXH_STRIPE_LEN;
4802
statePtr->nbStripesPerBlock = statePtr->secretLimit / XXH_SECRET_CONSUME_RATE;
4803
}
4804
4805
/*! @ingroup xxh3_family */
4806
XXH_PUBLIC_API XXH_errorcode
4807
XXH3_64bits_reset(XXH3_state_t* statePtr)
4808
{
4809
if (statePtr == NULL) return XXH_ERROR;
4810
XXH3_reset_internal(statePtr, 0, XXH3_kSecret, XXH_SECRET_DEFAULT_SIZE);
4811
return XXH_OK;
4812
}
4813
4814
/*! @ingroup xxh3_family */
4815
XXH_PUBLIC_API XXH_errorcode
4816
XXH3_64bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
4817
{
4818
if (statePtr == NULL) return XXH_ERROR;
4819
XXH3_reset_internal(statePtr, 0, secret, secretSize);
4820
if (secret == NULL) return XXH_ERROR;
4821
if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
4822
return XXH_OK;
4823
}
4824
4825
/*! @ingroup xxh3_family */
4826
XXH_PUBLIC_API XXH_errorcode
4827
XXH3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
4828
{
4829
if (statePtr == NULL) return XXH_ERROR;
4830
if (seed==0) return XXH3_64bits_reset(statePtr);
4831
if ((seed != statePtr->seed) || (statePtr->extSecret != NULL))
4832
XXH3_initCustomSecret(statePtr->customSecret, seed);
4833
XXH3_reset_internal(statePtr, seed, NULL, XXH_SECRET_DEFAULT_SIZE);
4834
return XXH_OK;
4835
}
4836
4837
/*! @ingroup xxh3_family */
4838
XXH_PUBLIC_API XXH_errorcode
4839
XXH3_64bits_reset_withSecretandSeed(XXH3_state_t* statePtr, const void* secret, size_t secretSize, XXH64_hash_t seed64)
4840
{
4841
if (statePtr == NULL) return XXH_ERROR;
4842
if (secret == NULL) return XXH_ERROR;
4843
if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
4844
XXH3_reset_internal(statePtr, seed64, secret, secretSize);
4845
statePtr->useSeed = 1; /* always, even if seed64==0 */
4846
return XXH_OK;
4847
}
4848
4849
/* Note : when XXH3_consumeStripes() is invoked,
4850
* there must be a guarantee that at least one more byte must be consumed from input
4851
* so that the function can blindly consume all stripes using the "normal" secret segment */
4852
XXH_FORCE_INLINE void
4853
XXH3_consumeStripes(xxh_u64* XXH_RESTRICT acc,
4854
size_t* XXH_RESTRICT nbStripesSoFarPtr, size_t nbStripesPerBlock,
4855
const xxh_u8* XXH_RESTRICT input, size_t nbStripes,
4856
const xxh_u8* XXH_RESTRICT secret, size_t secretLimit,
4857
XXH3_f_accumulate_512 f_acc512,
4858
XXH3_f_scrambleAcc f_scramble)
4859
{
4860
XXH_ASSERT(nbStripes <= nbStripesPerBlock); /* can handle max 1 scramble per invocation */
4861
XXH_ASSERT(*nbStripesSoFarPtr < nbStripesPerBlock);
4862
if (nbStripesPerBlock - *nbStripesSoFarPtr <= nbStripes) {
4863
/* need a scrambling operation */
4864
size_t const nbStripesToEndofBlock = nbStripesPerBlock - *nbStripesSoFarPtr;
4865
size_t const nbStripesAfterBlock = nbStripes - nbStripesToEndofBlock;
4866
XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, nbStripesToEndofBlock, f_acc512);
4867
f_scramble(acc, secret + secretLimit);
4868
XXH3_accumulate(acc, input + nbStripesToEndofBlock * XXH_STRIPE_LEN, secret, nbStripesAfterBlock, f_acc512);
4869
*nbStripesSoFarPtr = nbStripesAfterBlock;
4870
} else {
4871
XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, nbStripes, f_acc512);
4872
*nbStripesSoFarPtr += nbStripes;
4873
}
4874
}
4875
4876
#ifndef XXH3_STREAM_USE_STACK
4877
# ifndef __clang__ /* clang doesn't need additional stack space */
4878
# define XXH3_STREAM_USE_STACK 1
4879
# endif
4880
#endif
4881
/*
4882
* Both XXH3_64bits_update and XXH3_128bits_update use this routine.
4883
*/
4884
XXH_FORCE_INLINE XXH_errorcode
4885
XXH3_update(XXH3_state_t* XXH_RESTRICT const state,
4886
const xxh_u8* XXH_RESTRICT input, size_t len,
4887
XXH3_f_accumulate_512 f_acc512,
4888
XXH3_f_scrambleAcc f_scramble)
4889
{
4890
if (input==NULL) {
4891
XXH_ASSERT(len == 0);
4892
return XXH_OK;
4893
}
4894
4895
XXH_ASSERT(state != NULL);
4896
{ const xxh_u8* const bEnd = input + len;
4897
const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
4898
#if defined(XXH3_STREAM_USE_STACK) && XXH3_STREAM_USE_STACK >= 1
4899
/* For some reason, gcc and MSVC seem to suffer greatly
4900
* when operating accumulators directly into state.
4901
* Operating into stack space seems to enable proper optimization.
4902
* clang, on the other hand, doesn't seem to need this trick */
4903
XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[8]; memcpy(acc, state->acc, sizeof(acc));
4904
#else
4905
xxh_u64* XXH_RESTRICT const acc = state->acc;
4906
#endif
4907
state->totalLen += len;
4908
XXH_ASSERT(state->bufferedSize <= XXH3_INTERNALBUFFER_SIZE);
4909
4910
/* small input : just fill in tmp buffer */
4911
if (state->bufferedSize + len <= XXH3_INTERNALBUFFER_SIZE) {
4912
XXH_memcpy(state->buffer + state->bufferedSize, input, len);
4913
state->bufferedSize += (XXH32_hash_t)len;
4914
return XXH_OK;
4915
}
4916
4917
/* total input is now > XXH3_INTERNALBUFFER_SIZE */
4918
#define XXH3_INTERNALBUFFER_STRIPES (XXH3_INTERNALBUFFER_SIZE / XXH_STRIPE_LEN)
4919
XXH_STATIC_ASSERT(XXH3_INTERNALBUFFER_SIZE % XXH_STRIPE_LEN == 0); /* clean multiple */
4920
4921
/*
4922
* Internal buffer is partially filled (always, except at beginning)
4923
* Complete it, then consume it.
4924
*/
4925
if (state->bufferedSize) {
4926
size_t const loadSize = XXH3_INTERNALBUFFER_SIZE - state->bufferedSize;
4927
XXH_memcpy(state->buffer + state->bufferedSize, input, loadSize);
4928
input += loadSize;
4929
XXH3_consumeStripes(acc,
4930
&state->nbStripesSoFar, state->nbStripesPerBlock,
4931
state->buffer, XXH3_INTERNALBUFFER_STRIPES,
4932
secret, state->secretLimit,
4933
f_acc512, f_scramble);
4934
state->bufferedSize = 0;
4935
}
4936
XXH_ASSERT(input < bEnd);
4937
4938
/* large input to consume : ingest per full block */
4939
if ((size_t)(bEnd - input) > state->nbStripesPerBlock * XXH_STRIPE_LEN) {
4940
size_t nbStripes = (size_t)(bEnd - 1 - input) / XXH_STRIPE_LEN;
4941
XXH_ASSERT(state->nbStripesPerBlock >= state->nbStripesSoFar);
4942
/* join to current block's end */
4943
{ size_t const nbStripesToEnd = state->nbStripesPerBlock - state->nbStripesSoFar;
4944
XXH_ASSERT(nbStripesToEnd <= nbStripes);
4945
XXH3_accumulate(acc, input, secret + state->nbStripesSoFar * XXH_SECRET_CONSUME_RATE, nbStripesToEnd, f_acc512);
4946
f_scramble(acc, secret + state->secretLimit);
4947
state->nbStripesSoFar = 0;
4948
input += nbStripesToEnd * XXH_STRIPE_LEN;
4949
nbStripes -= nbStripesToEnd;
4950
}
4951
/* consume per entire blocks */
4952
while(nbStripes >= state->nbStripesPerBlock) {
4953
XXH3_accumulate(acc, input, secret, state->nbStripesPerBlock, f_acc512);
4954
f_scramble(acc, secret + state->secretLimit);
4955
input += state->nbStripesPerBlock * XXH_STRIPE_LEN;
4956
nbStripes -= state->nbStripesPerBlock;
4957
}
4958
/* consume last partial block */
4959
XXH3_accumulate(acc, input, secret, nbStripes, f_acc512);
4960
input += nbStripes * XXH_STRIPE_LEN;
4961
XXH_ASSERT(input < bEnd); /* at least some bytes left */
4962
state->nbStripesSoFar = nbStripes;
4963
/* buffer predecessor of last partial stripe */
4964
XXH_memcpy(state->buffer + sizeof(state->buffer) - XXH_STRIPE_LEN, input - XXH_STRIPE_LEN, XXH_STRIPE_LEN);
4965
XXH_ASSERT(bEnd - input <= XXH_STRIPE_LEN);
4966
} else {
4967
/* content to consume <= block size */
4968
/* Consume input by a multiple of internal buffer size */
4969
if (bEnd - input > XXH3_INTERNALBUFFER_SIZE) {
4970
const xxh_u8* const limit = bEnd - XXH3_INTERNALBUFFER_SIZE;
4971
do {
4972
XXH3_consumeStripes(acc,
4973
&state->nbStripesSoFar, state->nbStripesPerBlock,
4974
input, XXH3_INTERNALBUFFER_STRIPES,
4975
secret, state->secretLimit,
4976
f_acc512, f_scramble);
4977
input += XXH3_INTERNALBUFFER_SIZE;
4978
} while (input<limit);
4979
/* buffer predecessor of last partial stripe */
4980
XXH_memcpy(state->buffer + sizeof(state->buffer) - XXH_STRIPE_LEN, input - XXH_STRIPE_LEN, XXH_STRIPE_LEN);
4981
}
4982
}
4983
4984
/* Some remaining input (always) : buffer it */
4985
XXH_ASSERT(input < bEnd);
4986
XXH_ASSERT(bEnd - input <= XXH3_INTERNALBUFFER_SIZE);
4987
XXH_ASSERT(state->bufferedSize == 0);
4988
XXH_memcpy(state->buffer, input, (size_t)(bEnd-input));
4989
state->bufferedSize = (XXH32_hash_t)(bEnd-input);
4990
#if defined(XXH3_STREAM_USE_STACK) && XXH3_STREAM_USE_STACK >= 1
4991
/* save stack accumulators into state */
4992
memcpy(state->acc, acc, sizeof(acc));
4993
#endif
4994
}
4995
4996
return XXH_OK;
4997
}
4998
4999
/*! @ingroup xxh3_family */
5000
XXH_PUBLIC_API XXH_errorcode
5001
XXH3_64bits_update(XXH3_state_t* state, const void* input, size_t len)
5002
{
5003
return XXH3_update(state, (const xxh_u8*)input, len,
5004
XXH3_accumulate_512, XXH3_scrambleAcc);
5005
}
5006
5007
5008
XXH_FORCE_INLINE void
5009
XXH3_digest_long (XXH64_hash_t* acc,
5010
const XXH3_state_t* state,
5011
const unsigned char* secret)
5012
{
5013
/*
5014
* Digest on a local copy. This way, the state remains unaltered, and it can
5015
* continue ingesting more input afterwards.
5016
*/
5017
XXH_memcpy(acc, state->acc, sizeof(state->acc));
5018
if (state->bufferedSize >= XXH_STRIPE_LEN) {
5019
size_t const nbStripes = (state->bufferedSize - 1) / XXH_STRIPE_LEN;
5020
size_t nbStripesSoFar = state->nbStripesSoFar;
5021
XXH3_consumeStripes(acc,
5022
&nbStripesSoFar, state->nbStripesPerBlock,
5023
state->buffer, nbStripes,
5024
secret, state->secretLimit,
5025
XXH3_accumulate_512, XXH3_scrambleAcc);
5026
/* last stripe */
5027
XXH3_accumulate_512(acc,
5028
state->buffer + state->bufferedSize - XXH_STRIPE_LEN,
5029
secret + state->secretLimit - XXH_SECRET_LASTACC_START);
5030
} else { /* bufferedSize < XXH_STRIPE_LEN */
5031
xxh_u8 lastStripe[XXH_STRIPE_LEN];
5032
size_t const catchupSize = XXH_STRIPE_LEN - state->bufferedSize;
5033
XXH_ASSERT(state->bufferedSize > 0); /* there is always some input buffered */
5034
XXH_memcpy(lastStripe, state->buffer + sizeof(state->buffer) - catchupSize, catchupSize);
5035
XXH_memcpy(lastStripe + catchupSize, state->buffer, state->bufferedSize);
5036
XXH3_accumulate_512(acc,
5037
lastStripe,
5038
secret + state->secretLimit - XXH_SECRET_LASTACC_START);
5039
}
5040
}
5041
5042
/*! @ingroup xxh3_family */
5043
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_digest (const XXH3_state_t* state)
5044
{
5045
const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
5046
if (state->totalLen > XXH3_MIDSIZE_MAX) {
5047
XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
5048
XXH3_digest_long(acc, state, secret);
5049
return XXH3_mergeAccs(acc,
5050
secret + XXH_SECRET_MERGEACCS_START,
5051
(xxh_u64)state->totalLen * XXH_PRIME64_1);
5052
}
5053
/* totalLen <= XXH3_MIDSIZE_MAX: digesting a short input */
5054
if (state->useSeed)
5055
return XXH3_64bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
5056
return XXH3_64bits_withSecret(state->buffer, (size_t)(state->totalLen),
5057
secret, state->secretLimit + XXH_STRIPE_LEN);
5058
}
5059
5060
5061
5062
/* ==========================================
5063
* XXH3 128 bits (a.k.a XXH128)
5064
* ==========================================
5065
* XXH3's 128-bit variant has better mixing and strength than the 64-bit variant,
5066
* even without counting the significantly larger output size.
5067
*
5068
* For example, extra steps are taken to avoid the seed-dependent collisions
5069
* in 17-240 byte inputs (See XXH3_mix16B and XXH128_mix32B).
5070
*
5071
* This strength naturally comes at the cost of some speed, especially on short
5072
* lengths. Note that longer hashes are about as fast as the 64-bit version
5073
* due to it using only a slight modification of the 64-bit loop.
5074
*
5075
* XXH128 is also more oriented towards 64-bit machines. It is still extremely
5076
* fast for a _128-bit_ hash on 32-bit (it usually clears XXH64).
5077
*/
5078
5079
XXH_FORCE_INLINE XXH128_hash_t
5080
XXH3_len_1to3_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5081
{
5082
/* A doubled version of 1to3_64b with different constants. */
5083
XXH_ASSERT(input != NULL);
5084
XXH_ASSERT(1 <= len && len <= 3);
5085
XXH_ASSERT(secret != NULL);
5086
/*
5087
* len = 1: combinedl = { input[0], 0x01, input[0], input[0] }
5088
* len = 2: combinedl = { input[1], 0x02, input[0], input[1] }
5089
* len = 3: combinedl = { input[2], 0x03, input[0], input[1] }
5090
*/
5091
{ xxh_u8 const c1 = input[0];
5092
xxh_u8 const c2 = input[len >> 1];
5093
xxh_u8 const c3 = input[len - 1];
5094
xxh_u32 const combinedl = ((xxh_u32)c1 <<16) | ((xxh_u32)c2 << 24)
5095
| ((xxh_u32)c3 << 0) | ((xxh_u32)len << 8);
5096
xxh_u32 const combinedh = XXH_rotl32(XXH_swap32(combinedl), 13);
5097
xxh_u64 const bitflipl = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
5098
xxh_u64 const bitfliph = (XXH_readLE32(secret+8) ^ XXH_readLE32(secret+12)) - seed;
5099
xxh_u64 const keyed_lo = (xxh_u64)combinedl ^ bitflipl;
5100
xxh_u64 const keyed_hi = (xxh_u64)combinedh ^ bitfliph;
5101
XXH128_hash_t h128;
5102
h128.low64 = XXH64_avalanche(keyed_lo);
5103
h128.high64 = XXH64_avalanche(keyed_hi);
5104
return h128;
5105
}
5106
}
5107
5108
XXH_FORCE_INLINE XXH128_hash_t
5109
XXH3_len_4to8_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5110
{
5111
XXH_ASSERT(input != NULL);
5112
XXH_ASSERT(secret != NULL);
5113
XXH_ASSERT(4 <= len && len <= 8);
5114
seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
5115
{ xxh_u32 const input_lo = XXH_readLE32(input);
5116
xxh_u32 const input_hi = XXH_readLE32(input + len - 4);
5117
xxh_u64 const input_64 = input_lo + ((xxh_u64)input_hi << 32);
5118
xxh_u64 const bitflip = (XXH_readLE64(secret+16) ^ XXH_readLE64(secret+24)) + seed;
5119
xxh_u64 const keyed = input_64 ^ bitflip;
5120
5121
/* Shift len to the left to ensure it is even, this avoids even multiplies. */
5122
XXH128_hash_t m128 = XXH_mult64to128(keyed, XXH_PRIME64_1 + (len << 2));
5123
5124
m128.high64 += (m128.low64 << 1);
5125
m128.low64 ^= (m128.high64 >> 3);
5126
5127
m128.low64 = XXH_xorshift64(m128.low64, 35);
5128
m128.low64 *= 0x9FB21C651E98DF25ULL;
5129
m128.low64 = XXH_xorshift64(m128.low64, 28);
5130
m128.high64 = XXH3_avalanche(m128.high64);
5131
return m128;
5132
}
5133
}
5134
5135
XXH_FORCE_INLINE XXH128_hash_t
5136
XXH3_len_9to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5137
{
5138
XXH_ASSERT(input != NULL);
5139
XXH_ASSERT(secret != NULL);
5140
XXH_ASSERT(9 <= len && len <= 16);
5141
{ xxh_u64 const bitflipl = (XXH_readLE64(secret+32) ^ XXH_readLE64(secret+40)) - seed;
5142
xxh_u64 const bitfliph = (XXH_readLE64(secret+48) ^ XXH_readLE64(secret+56)) + seed;
5143
xxh_u64 const input_lo = XXH_readLE64(input);
5144
xxh_u64 input_hi = XXH_readLE64(input + len - 8);
5145
XXH128_hash_t m128 = XXH_mult64to128(input_lo ^ input_hi ^ bitflipl, XXH_PRIME64_1);
5146
/*
5147
* Put len in the middle of m128 to ensure that the length gets mixed to
5148
* both the low and high bits in the 128x64 multiply below.
5149
*/
5150
m128.low64 += (xxh_u64)(len - 1) << 54;
5151
input_hi ^= bitfliph;
5152
/*
5153
* Add the high 32 bits of input_hi to the high 32 bits of m128, then
5154
* add the long product of the low 32 bits of input_hi and XXH_PRIME32_2 to
5155
* the high 64 bits of m128.
5156
*
5157
* The best approach to this operation is different on 32-bit and 64-bit.
5158
*/
5159
if (sizeof(void *) < sizeof(xxh_u64)) { /* 32-bit */
5160
/*
5161
* 32-bit optimized version, which is more readable.
5162
*
5163
* On 32-bit, it removes an ADC and delays a dependency between the two
5164
* halves of m128.high64, but it generates an extra mask on 64-bit.
5165
*/
5166
m128.high64 += (input_hi & 0xFFFFFFFF00000000ULL) + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2);
5167
} else {
5168
/*
5169
* 64-bit optimized (albeit more confusing) version.
5170
*
5171
* Uses some properties of addition and multiplication to remove the mask:
5172
*
5173
* Let:
5174
* a = input_hi.lo = (input_hi & 0x00000000FFFFFFFF)
5175
* b = input_hi.hi = (input_hi & 0xFFFFFFFF00000000)
5176
* c = XXH_PRIME32_2
5177
*
5178
* a + (b * c)
5179
* Inverse Property: x + y - x == y
5180
* a + (b * (1 + c - 1))
5181
* Distributive Property: x * (y + z) == (x * y) + (x * z)
5182
* a + (b * 1) + (b * (c - 1))
5183
* Identity Property: x * 1 == x
5184
* a + b + (b * (c - 1))
5185
*
5186
* Substitute a, b, and c:
5187
* input_hi.hi + input_hi.lo + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
5188
*
5189
* Since input_hi.hi + input_hi.lo == input_hi, we get this:
5190
* input_hi + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
5191
*/
5192
m128.high64 += input_hi + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2 - 1);
5193
}
5194
/* m128 ^= XXH_swap64(m128 >> 64); */
5195
m128.low64 ^= XXH_swap64(m128.high64);
5196
5197
{ /* 128x64 multiply: h128 = m128 * XXH_PRIME64_2; */
5198
XXH128_hash_t h128 = XXH_mult64to128(m128.low64, XXH_PRIME64_2);
5199
h128.high64 += m128.high64 * XXH_PRIME64_2;
5200
5201
h128.low64 = XXH3_avalanche(h128.low64);
5202
h128.high64 = XXH3_avalanche(h128.high64);
5203
return h128;
5204
} }
5205
}
5206
5207
/*
5208
* Assumption: `secret` size is >= XXH3_SECRET_SIZE_MIN
5209
*/
5210
XXH_FORCE_INLINE XXH128_hash_t
5211
XXH3_len_0to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5212
{
5213
XXH_ASSERT(len <= 16);
5214
{ if (len > 8) return XXH3_len_9to16_128b(input, len, secret, seed);
5215
if (len >= 4) return XXH3_len_4to8_128b(input, len, secret, seed);
5216
if (len) return XXH3_len_1to3_128b(input, len, secret, seed);
5217
{ XXH128_hash_t h128;
5218
xxh_u64 const bitflipl = XXH_readLE64(secret+64) ^ XXH_readLE64(secret+72);
5219
xxh_u64 const bitfliph = XXH_readLE64(secret+80) ^ XXH_readLE64(secret+88);
5220
h128.low64 = XXH64_avalanche(seed ^ bitflipl);
5221
h128.high64 = XXH64_avalanche( seed ^ bitfliph);
5222
return h128;
5223
} }
5224
}
5225
5226
/*
5227
* A bit slower than XXH3_mix16B, but handles multiply by zero better.
5228
*/
5229
XXH_FORCE_INLINE XXH128_hash_t
5230
XXH128_mix32B(XXH128_hash_t acc, const xxh_u8* input_1, const xxh_u8* input_2,
5231
const xxh_u8* secret, XXH64_hash_t seed)
5232
{
5233
acc.low64 += XXH3_mix16B (input_1, secret+0, seed);
5234
acc.low64 ^= XXH_readLE64(input_2) + XXH_readLE64(input_2 + 8);
5235
acc.high64 += XXH3_mix16B (input_2, secret+16, seed);
5236
acc.high64 ^= XXH_readLE64(input_1) + XXH_readLE64(input_1 + 8);
5237
return acc;
5238
}
5239
5240
5241
XXH_FORCE_INLINE XXH128_hash_t
5242
XXH3_len_17to128_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
5243
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
5244
XXH64_hash_t seed)
5245
{
5246
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
5247
XXH_ASSERT(16 < len && len <= 128);
5248
5249
{ XXH128_hash_t acc;
5250
acc.low64 = len * XXH_PRIME64_1;
5251
acc.high64 = 0;
5252
if (len > 32) {
5253
if (len > 64) {
5254
if (len > 96) {
5255
acc = XXH128_mix32B(acc, input+48, input+len-64, secret+96, seed);
5256
}
5257
acc = XXH128_mix32B(acc, input+32, input+len-48, secret+64, seed);
5258
}
5259
acc = XXH128_mix32B(acc, input+16, input+len-32, secret+32, seed);
5260
}
5261
acc = XXH128_mix32B(acc, input, input+len-16, secret, seed);
5262
{ XXH128_hash_t h128;
5263
h128.low64 = acc.low64 + acc.high64;
5264
h128.high64 = (acc.low64 * XXH_PRIME64_1)
5265
+ (acc.high64 * XXH_PRIME64_4)
5266
+ ((len - seed) * XXH_PRIME64_2);
5267
h128.low64 = XXH3_avalanche(h128.low64);
5268
h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
5269
return h128;
5270
}
5271
}
5272
}
5273
5274
XXH_NO_INLINE XXH128_hash_t
5275
XXH3_len_129to240_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
5276
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
5277
XXH64_hash_t seed)
5278
{
5279
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
5280
XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
5281
5282
{ XXH128_hash_t acc;
5283
int const nbRounds = (int)len / 32;
5284
int i;
5285
acc.low64 = len * XXH_PRIME64_1;
5286
acc.high64 = 0;
5287
for (i=0; i<4; i++) {
5288
acc = XXH128_mix32B(acc,
5289
input + (32 * i),
5290
input + (32 * i) + 16,
5291
secret + (32 * i),
5292
seed);
5293
}
5294
acc.low64 = XXH3_avalanche(acc.low64);
5295
acc.high64 = XXH3_avalanche(acc.high64);
5296
XXH_ASSERT(nbRounds >= 4);
5297
for (i=4 ; i < nbRounds; i++) {
5298
acc = XXH128_mix32B(acc,
5299
input + (32 * i),
5300
input + (32 * i) + 16,
5301
secret + XXH3_MIDSIZE_STARTOFFSET + (32 * (i - 4)),
5302
seed);
5303
}
5304
/* last bytes */
5305
acc = XXH128_mix32B(acc,
5306
input + len - 16,
5307
input + len - 32,
5308
secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET - 16,
5309
0ULL - seed);
5310
5311
{ XXH128_hash_t h128;
5312
h128.low64 = acc.low64 + acc.high64;
5313
h128.high64 = (acc.low64 * XXH_PRIME64_1)
5314
+ (acc.high64 * XXH_PRIME64_4)
5315
+ ((len - seed) * XXH_PRIME64_2);
5316
h128.low64 = XXH3_avalanche(h128.low64);
5317
h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
5318
return h128;
5319
}
5320
}
5321
}
5322
5323
XXH_FORCE_INLINE XXH128_hash_t
5324
XXH3_hashLong_128b_internal(const void* XXH_RESTRICT input, size_t len,
5325
const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
5326
XXH3_f_accumulate_512 f_acc512,
5327
XXH3_f_scrambleAcc f_scramble)
5328
{
5329
XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;
5330
5331
XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, secret, secretSize, f_acc512, f_scramble);
5332
5333
/* converge into final hash */
5334
XXH_STATIC_ASSERT(sizeof(acc) == 64);
5335
XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
5336
{ XXH128_hash_t h128;
5337
h128.low64 = XXH3_mergeAccs(acc,
5338
secret + XXH_SECRET_MERGEACCS_START,
5339
(xxh_u64)len * XXH_PRIME64_1);
5340
h128.high64 = XXH3_mergeAccs(acc,
5341
secret + secretSize
5342
- sizeof(acc) - XXH_SECRET_MERGEACCS_START,
5343
~((xxh_u64)len * XXH_PRIME64_2));
5344
return h128;
5345
}
5346
}
5347
5348
/*
5349
* It's important for performance that XXH3_hashLong is not inlined.
5350
*/
5351
XXH_NO_INLINE XXH128_hash_t
5352
XXH3_hashLong_128b_default(const void* XXH_RESTRICT input, size_t len,
5353
XXH64_hash_t seed64,
5354
const void* XXH_RESTRICT secret, size_t secretLen)
5355
{
5356
(void)seed64; (void)secret; (void)secretLen;
5357
return XXH3_hashLong_128b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret),
5358
XXH3_accumulate_512, XXH3_scrambleAcc);
5359
}
5360
5361
/*
5362
* It's important for performance to pass @secretLen (when it's static)
5363
* to the compiler, so that it can properly optimize the vectorized loop.
5364
*/
5365
XXH_FORCE_INLINE XXH128_hash_t
5366
XXH3_hashLong_128b_withSecret(const void* XXH_RESTRICT input, size_t len,
5367
XXH64_hash_t seed64,
5368
const void* XXH_RESTRICT secret, size_t secretLen)
5369
{
5370
(void)seed64;
5371
return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, secretLen,
5372
XXH3_accumulate_512, XXH3_scrambleAcc);
5373
}
5374
5375
XXH_FORCE_INLINE XXH128_hash_t
5376
XXH3_hashLong_128b_withSeed_internal(const void* XXH_RESTRICT input, size_t len,
5377
XXH64_hash_t seed64,
5378
XXH3_f_accumulate_512 f_acc512,
5379
XXH3_f_scrambleAcc f_scramble,
5380
XXH3_f_initCustomSecret f_initSec)
5381
{
5382
if (seed64 == 0)
5383
return XXH3_hashLong_128b_internal(input, len,
5384
XXH3_kSecret, sizeof(XXH3_kSecret),
5385
f_acc512, f_scramble);
5386
{ XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
5387
f_initSec(secret, seed64);
5388
return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, sizeof(secret),
5389
f_acc512, f_scramble);
5390
}
5391
}
5392
5393
/*
5394
* It's important for performance that XXH3_hashLong is not inlined.
5395
*/
5396
XXH_NO_INLINE XXH128_hash_t
5397
XXH3_hashLong_128b_withSeed(const void* input, size_t len,
5398
XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen)
5399
{
5400
(void)secret; (void)secretLen;
5401
return XXH3_hashLong_128b_withSeed_internal(input, len, seed64,
5402
XXH3_accumulate_512, XXH3_scrambleAcc, XXH3_initCustomSecret);
5403
}
5404
5405
typedef XXH128_hash_t (*XXH3_hashLong128_f)(const void* XXH_RESTRICT, size_t,
5406
XXH64_hash_t, const void* XXH_RESTRICT, size_t);
5407
5408
XXH_FORCE_INLINE XXH128_hash_t
5409
XXH3_128bits_internal(const void* input, size_t len,
5410
XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
5411
XXH3_hashLong128_f f_hl128)
5412
{
5413
XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
5414
/*
5415
* If an action is to be taken if `secret` conditions are not respected,
5416
* it should be done here.
5417
* For now, it's a contract pre-condition.
5418
* Adding a check and a branch here would cost performance at every hash.
5419
*/
5420
if (len <= 16)
5421
return XXH3_len_0to16_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
5422
if (len <= 128)
5423
return XXH3_len_17to128_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
5424
if (len <= XXH3_MIDSIZE_MAX)
5425
return XXH3_len_129to240_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
5426
return f_hl128(input, len, seed64, secret, secretLen);
5427
}
5428
5429
5430
/* === Public XXH128 API === */
5431
5432
/*! @ingroup xxh3_family */
5433
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(const void* input, size_t len)
5434
{
5435
return XXH3_128bits_internal(input, len, 0,
5436
XXH3_kSecret, sizeof(XXH3_kSecret),
5437
XXH3_hashLong_128b_default);
5438
}
5439
5440
/*! @ingroup xxh3_family */
5441
XXH_PUBLIC_API XXH128_hash_t
5442
XXH3_128bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
5443
{
5444
return XXH3_128bits_internal(input, len, 0,
5445
(const xxh_u8*)secret, secretSize,
5446
XXH3_hashLong_128b_withSecret);
5447
}
5448
5449
/*! @ingroup xxh3_family */
5450
XXH_PUBLIC_API XXH128_hash_t
5451
XXH3_128bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
5452
{
5453
return XXH3_128bits_internal(input, len, seed,
5454
XXH3_kSecret, sizeof(XXH3_kSecret),
5455
XXH3_hashLong_128b_withSeed);
5456
}
5457
5458
/*! @ingroup xxh3_family */
5459
XXH_PUBLIC_API XXH128_hash_t
5460
XXH3_128bits_withSecretandSeed(const void* input, size_t len, const void* secret, size_t secretSize, XXH64_hash_t seed)
5461
{
5462
if (len <= XXH3_MIDSIZE_MAX)
5463
return XXH3_128bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), NULL);
5464
return XXH3_hashLong_128b_withSecret(input, len, seed, secret, secretSize);
5465
}
5466
5467
/*! @ingroup xxh3_family */
5468
XXH_PUBLIC_API XXH128_hash_t
5469
XXH128(const void* input, size_t len, XXH64_hash_t seed)
5470
{
5471
return XXH3_128bits_withSeed(input, len, seed);
5472
}
5473
5474
5475
/* === XXH3 128-bit streaming === */
5476
5477
/*
5478
* All initialization and update functions are identical to 64-bit streaming variant.
5479
* The only difference is the finalization routine.
5480
*/
5481
5482
/*! @ingroup xxh3_family */
5483
XXH_PUBLIC_API XXH_errorcode
5484
XXH3_128bits_reset(XXH3_state_t* statePtr)
5485
{
5486
return XXH3_64bits_reset(statePtr);
5487
}
5488
5489
/*! @ingroup xxh3_family */
5490
XXH_PUBLIC_API XXH_errorcode
5491
XXH3_128bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
5492
{
5493
return XXH3_64bits_reset_withSecret(statePtr, secret, secretSize);
5494
}
5495
5496
/*! @ingroup xxh3_family */
5497
XXH_PUBLIC_API XXH_errorcode
5498
XXH3_128bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
5499
{
5500
return XXH3_64bits_reset_withSeed(statePtr, seed);
5501
}
5502
5503
/*! @ingroup xxh3_family */
5504
XXH_PUBLIC_API XXH_errorcode
5505
XXH3_128bits_reset_withSecretandSeed(XXH3_state_t* statePtr, const void* secret, size_t secretSize, XXH64_hash_t seed)
5506
{
5507
return XXH3_64bits_reset_withSecretandSeed(statePtr, secret, secretSize, seed);
5508
}
5509
5510
/*! @ingroup xxh3_family */
5511
XXH_PUBLIC_API XXH_errorcode
5512
XXH3_128bits_update(XXH3_state_t* state, const void* input, size_t len)
5513
{
5514
return XXH3_update(state, (const xxh_u8*)input, len,
5515
XXH3_accumulate_512, XXH3_scrambleAcc);
5516
}
5517
5518
/*! @ingroup xxh3_family */
5519
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (const XXH3_state_t* state)
5520
{
5521
const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
5522
if (state->totalLen > XXH3_MIDSIZE_MAX) {
5523
XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
5524
XXH3_digest_long(acc, state, secret);
5525
XXH_ASSERT(state->secretLimit + XXH_STRIPE_LEN >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
5526
{ XXH128_hash_t h128;
5527
h128.low64 = XXH3_mergeAccs(acc,
5528
secret + XXH_SECRET_MERGEACCS_START,
5529
(xxh_u64)state->totalLen * XXH_PRIME64_1);
5530
h128.high64 = XXH3_mergeAccs(acc,
5531
secret + state->secretLimit + XXH_STRIPE_LEN
5532
- sizeof(acc) - XXH_SECRET_MERGEACCS_START,
5533
~((xxh_u64)state->totalLen * XXH_PRIME64_2));
5534
return h128;
5535
}
5536
}
5537
/* len <= XXH3_MIDSIZE_MAX : short code */
5538
if (state->seed)
5539
return XXH3_128bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
5540
return XXH3_128bits_withSecret(state->buffer, (size_t)(state->totalLen),
5541
secret, state->secretLimit + XXH_STRIPE_LEN);
5542
}
5543
5544
/* 128-bit utility functions */
5545
5546
#include <string.h> /* memcmp, memcpy */
5547
5548
/* return : 1 is equal, 0 if different */
5549
/*! @ingroup xxh3_family */
5550
XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2)
5551
{
5552
/* note : XXH128_hash_t is compact, it has no padding byte */
5553
return !(memcmp(&h1, &h2, sizeof(h1)));
5554
}
5555
5556
/* This prototype is compatible with stdlib's qsort().
5557
* return : >0 if *h128_1 > *h128_2
5558
* <0 if *h128_1 < *h128_2
5559
* =0 if *h128_1 == *h128_2 */
5560
/*! @ingroup xxh3_family */
5561
XXH_PUBLIC_API int XXH128_cmp(const void* h128_1, const void* h128_2)
5562
{
5563
XXH128_hash_t const h1 = *(const XXH128_hash_t*)h128_1;
5564
XXH128_hash_t const h2 = *(const XXH128_hash_t*)h128_2;
5565
int const hcmp = (h1.high64 > h2.high64) - (h2.high64 > h1.high64);
5566
/* note : bets that, in most cases, hash values are different */
5567
if (hcmp) return hcmp;
5568
return (h1.low64 > h2.low64) - (h2.low64 > h1.low64);
5569
}
5570
5571
5572
/*====== Canonical representation ======*/
5573
/*! @ingroup xxh3_family */
5574
XXH_PUBLIC_API void
5575
XXH128_canonicalFromHash(XXH128_canonical_t* dst, XXH128_hash_t hash)
5576
{
5577
XXH_STATIC_ASSERT(sizeof(XXH128_canonical_t) == sizeof(XXH128_hash_t));
5578
if (XXH_CPU_LITTLE_ENDIAN) {
5579
hash.high64 = XXH_swap64(hash.high64);
5580
hash.low64 = XXH_swap64(hash.low64);
5581
}
5582
XXH_memcpy(dst, &hash.high64, sizeof(hash.high64));
5583
XXH_memcpy((char*)dst + sizeof(hash.high64), &hash.low64, sizeof(hash.low64));
5584
}
5585
5586
/*! @ingroup xxh3_family */
5587
XXH_PUBLIC_API XXH128_hash_t
5588
XXH128_hashFromCanonical(const XXH128_canonical_t* src)
5589
{
5590
XXH128_hash_t h;
5591
h.high64 = XXH_readBE64(src);
5592
h.low64 = XXH_readBE64(src->digest + 8);
5593
return h;
5594
}
5595
5596
5597
5598
/* ==========================================
5599
* Secret generators
5600
* ==========================================
5601
*/
5602
#define XXH_MIN(x, y) (((x) > (y)) ? (y) : (x))
5603
5604
XXH_FORCE_INLINE void XXH3_combine16(void* dst, XXH128_hash_t h128)
5605
{
5606
XXH_writeLE64( dst, XXH_readLE64(dst) ^ h128.low64 );
5607
XXH_writeLE64( (char*)dst+8, XXH_readLE64((char*)dst+8) ^ h128.high64 );
5608
}
5609
5610
/*! @ingroup xxh3_family */
5611
XXH_PUBLIC_API XXH_errorcode
5612
XXH3_generateSecret(void* secretBuffer, size_t secretSize, const void* customSeed, size_t customSeedSize)
5613
{
5614
#if (XXH_DEBUGLEVEL >= 1)
5615
XXH_ASSERT(secretBuffer != NULL);
5616
XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
5617
#else
5618
/* production mode, assert() are disabled */
5619
if (secretBuffer == NULL) return XXH_ERROR;
5620
if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
5621
#endif
5622
5623
if (customSeedSize == 0) {
5624
customSeed = XXH3_kSecret;
5625
customSeedSize = XXH_SECRET_DEFAULT_SIZE;
5626
}
5627
#if (XXH_DEBUGLEVEL >= 1)
5628
XXH_ASSERT(customSeed != NULL);
5629
#else
5630
if (customSeed == NULL) return XXH_ERROR;
5631
#endif
5632
5633
/* Fill secretBuffer with a copy of customSeed - repeat as needed */
5634
{ size_t pos = 0;
5635
while (pos < secretSize) {
5636
size_t const toCopy = XXH_MIN((secretSize - pos), customSeedSize);
5637
memcpy((char*)secretBuffer + pos, customSeed, toCopy);
5638
pos += toCopy;
5639
} }
5640
5641
{ size_t const nbSeg16 = secretSize / 16;
5642
size_t n;
5643
XXH128_canonical_t scrambler;
5644
XXH128_canonicalFromHash(&scrambler, XXH128(customSeed, customSeedSize, 0));
5645
for (n=0; n<nbSeg16; n++) {
5646
XXH128_hash_t const h128 = XXH128(&scrambler, sizeof(scrambler), n);
5647
XXH3_combine16((char*)secretBuffer + n*16, h128);
5648
}
5649
/* last segment */
5650
XXH3_combine16((char*)secretBuffer + secretSize - 16, XXH128_hashFromCanonical(&scrambler));
5651
}
5652
return XXH_OK;
5653
}
5654
5655
/*! @ingroup xxh3_family */
5656
XXH_PUBLIC_API void
5657
XXH3_generateSecret_fromSeed(void* secretBuffer, XXH64_hash_t seed)
5658
{
5659
XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
5660
XXH3_initCustomSecret(secret, seed);
5661
XXH_ASSERT(secretBuffer != NULL);
5662
memcpy(secretBuffer, secret, XXH_SECRET_DEFAULT_SIZE);
5663
}
5664
5665
5666
5667
/* Pop our optimization override from above */
5668
#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
5669
&& defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
5670
&& defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
5671
# pragma GCC pop_options
5672
#endif
5673
5674
#endif /* XXH_NO_LONG_LONG */
5675
5676
#endif /* XXH_NO_XXH3 */
5677
5678
/*!
5679
* @}
5680
*/
5681
#endif /* XXH_IMPLEMENTATION */
5682
5683
5684
#if defined (__cplusplus)
5685
}
5686
#endif
5687
5688