duckstation

duckstation, but archived from the revision just before upstream changed it to a proprietary software project, this version is the libre one
git clone https://git.neptards.moe/u3shit/duckstation.git
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xxhash.h (204174B)


      1 /*
      2  * xxHash - Extremely Fast Hash algorithm
      3  * Header File
      4  * Copyright (C) 2012-2020 Yann Collet
      5  *
      6  * BSD 2-Clause License (https://www.opensource.org/licenses/bsd-license.php)
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions are
     10  * met:
     11  *
     12  *    * Redistributions of source code must retain the above copyright
     13  *      notice, this list of conditions and the following disclaimer.
     14  *    * Redistributions in binary form must reproduce the above
     15  *      copyright notice, this list of conditions and the following disclaimer
     16  *      in the documentation and/or other materials provided with the
     17  *      distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  *
     31  * You can contact the author at:
     32  *   - xxHash homepage: https://www.xxhash.com
     33  *   - xxHash source repository: https://github.com/Cyan4973/xxHash
     34  */
     35 /*!
     36  * @mainpage xxHash
     37  *
     38  * @file xxhash.h
     39  * xxHash prototypes and implementation
     40  */
     41 /* TODO: update */
     42 /* Notice extracted from xxHash homepage:
     43 
     44 xxHash is an extremely fast hash algorithm, running at RAM speed limits.
     45 It also successfully passes all tests from the SMHasher suite.
     46 
     47 Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
     48 
     49 Name            Speed       Q.Score   Author
     50 xxHash          5.4 GB/s     10
     51 CrapWow         3.2 GB/s      2       Andrew
     52 MurmurHash 3a   2.7 GB/s     10       Austin Appleby
     53 SpookyHash      2.0 GB/s     10       Bob Jenkins
     54 SBox            1.4 GB/s      9       Bret Mulvey
     55 Lookup3         1.2 GB/s      9       Bob Jenkins
     56 SuperFastHash   1.2 GB/s      1       Paul Hsieh
     57 CityHash64      1.05 GB/s    10       Pike & Alakuijala
     58 FNV             0.55 GB/s     5       Fowler, Noll, Vo
     59 CRC32           0.43 GB/s     9
     60 MD5-32          0.33 GB/s    10       Ronald L. Rivest
     61 SHA1-32         0.28 GB/s    10
     62 
     63 Q.Score is a measure of quality of the hash function.
     64 It depends on successfully passing SMHasher test set.
     65 10 is a perfect score.
     66 
     67 Note: SMHasher's CRC32 implementation is not the fastest one.
     68 Other speed-oriented implementations can be faster,
     69 especially in combination with PCLMUL instruction:
     70 https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html?showComment=1552696407071#c3490092340461170735
     71 
     72 A 64-bit version, named XXH64, is available since r35.
     73 It offers much better speed, but for 64-bit applications only.
     74 Name     Speed on 64 bits    Speed on 32 bits
     75 XXH64       13.8 GB/s            1.9 GB/s
     76 XXH32        6.8 GB/s            6.0 GB/s
     77 */
     78 
     79 #if defined (__cplusplus)
     80 extern "C" {
     81 #endif
     82 
     83 /* ****************************
     84  *  INLINE mode
     85  ******************************/
     86 /*!
     87  * XXH_INLINE_ALL (and XXH_PRIVATE_API)
     88  * Use these build macros to inline xxhash into the target unit.
     89  * Inlining improves performance on small inputs, especially when the length is
     90  * expressed as a compile-time constant:
     91  *
     92  *      https://fastcompression.blogspot.com/2018/03/xxhash-for-small-keys-impressive-power.html
     93  *
     94  * It also keeps xxHash symbols private to the unit, so they are not exported.
     95  *
     96  * Usage:
     97  *     #define XXH_INLINE_ALL
     98  *     #include "xxhash.h"
     99  *
    100  * Do not compile and link xxhash.o as a separate object, as it is not useful.
    101  */
    102 #if (defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)) \
    103     && !defined(XXH_INLINE_ALL_31684351384)
    104    /* this section should be traversed only once */
    105 #  define XXH_INLINE_ALL_31684351384
    106    /* give access to the advanced API, required to compile implementations */
    107 #  undef XXH_STATIC_LINKING_ONLY   /* avoid macro redef */
    108 #  define XXH_STATIC_LINKING_ONLY
    109    /* make all functions private */
    110 #  undef XXH_PUBLIC_API
    111 #  if defined(__GNUC__)
    112 #    define XXH_PUBLIC_API static __inline __attribute__((unused))
    113 #  elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
    114 #    define XXH_PUBLIC_API static inline
    115 #  elif defined(_MSC_VER)
    116 #    define XXH_PUBLIC_API static __inline
    117 #  else
    118      /* note: this version may generate warnings for unused static functions */
    119 #    define XXH_PUBLIC_API static
    120 #  endif
    121 
    122    /*
    123     * This part deals with the special case where a unit wants to inline xxHash,
    124     * but "xxhash.h" has previously been included without XXH_INLINE_ALL, such
    125     * as part of some previously included *.h header file.
    126     * Without further action, the new include would just be ignored,
    127     * and functions would effectively _not_ be inlined (silent failure).
    128     * The following macros solve this situation by prefixing all inlined names,
    129     * avoiding naming collision with previous inclusions.
    130     */
    131 #  ifdef XXH_NAMESPACE
    132 #    error "XXH_INLINE_ALL with XXH_NAMESPACE is not supported"
    133      /*
    134       * Note: Alternative: #undef all symbols (it's a pretty large list).
    135       * Without #error: it compiles, but functions are actually not inlined.
    136       */
    137 #  endif
    138 #  define XXH_NAMESPACE XXH_INLINE_
    139    /*
    140     * Some identifiers (enums, type names) are not symbols, but they must
    141     * still be renamed to avoid redeclaration.
    142     * Alternative solution: do not redeclare them.
    143     * However, this requires some #ifdefs, and is a more dispersed action.
    144     * Meanwhile, renaming can be achieved in a single block
    145     */
    146 #  define XXH_IPREF(Id)   XXH_INLINE_ ## Id
    147 #  define XXH_OK XXH_IPREF(XXH_OK)
    148 #  define XXH_ERROR XXH_IPREF(XXH_ERROR)
    149 #  define XXH_errorcode XXH_IPREF(XXH_errorcode)
    150 #  define XXH32_canonical_t  XXH_IPREF(XXH32_canonical_t)
    151 #  define XXH64_canonical_t  XXH_IPREF(XXH64_canonical_t)
    152 #  define XXH128_canonical_t XXH_IPREF(XXH128_canonical_t)
    153 #  define XXH32_state_s XXH_IPREF(XXH32_state_s)
    154 #  define XXH32_state_t XXH_IPREF(XXH32_state_t)
    155 #  define XXH64_state_s XXH_IPREF(XXH64_state_s)
    156 #  define XXH64_state_t XXH_IPREF(XXH64_state_t)
    157 #  define XXH3_state_s  XXH_IPREF(XXH3_state_s)
    158 #  define XXH3_state_t  XXH_IPREF(XXH3_state_t)
    159 #  define XXH128_hash_t XXH_IPREF(XXH128_hash_t)
    160    /* Ensure the header is parsed again, even if it was previously included */
    161 #  undef XXHASH_H_5627135585666179
    162 #  undef XXHASH_H_STATIC_13879238742
    163 #endif /* XXH_INLINE_ALL || XXH_PRIVATE_API */
    164 
    165 
    166 
    167 /* ****************************************************************
    168  *  Stable API
    169  *****************************************************************/
    170 #ifndef XXHASH_H_5627135585666179
    171 #define XXHASH_H_5627135585666179 1
    172 
    173 
    174 /*!
    175  * @defgroup public Public API
    176  * Contains details on the public xxHash functions.
    177  * @{
    178  */
    179 /* specific declaration modes for Windows */
    180 #if !defined(XXH_INLINE_ALL) && !defined(XXH_PRIVATE_API)
    181 #  if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
    182 #    ifdef XXH_EXPORT
    183 #      define XXH_PUBLIC_API __declspec(dllexport)
    184 #    elif XXH_IMPORT
    185 #      define XXH_PUBLIC_API __declspec(dllimport)
    186 #    endif
    187 #  else
    188 #    define XXH_PUBLIC_API   /* do nothing */
    189 #  endif
    190 #endif
    191 
    192 #ifdef XXH_DOXYGEN
    193 /*!
    194  * @brief Emulate a namespace by transparently prefixing all symbols.
    195  *
    196  * If you want to include _and expose_ xxHash functions from within your own
    197  * library, but also want to avoid symbol collisions with other libraries which
    198  * may also include xxHash, you can use XXH_NAMESPACE to automatically prefix
    199  * any public symbol from xxhash library with the value of XXH_NAMESPACE
    200  * (therefore, avoid empty or numeric values).
    201  *
    202  * Note that no change is required within the calling program as long as it
    203  * includes `xxhash.h`: Regular symbol names will be automatically translated
    204  * by this header.
    205  */
    206 #  define XXH_NAMESPACE /* YOUR NAME HERE */
    207 #  undef XXH_NAMESPACE
    208 #endif
    209 
    210 #ifdef XXH_NAMESPACE
    211 #  define XXH_CAT(A,B) A##B
    212 #  define XXH_NAME2(A,B) XXH_CAT(A,B)
    213 #  define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
    214 /* XXH32 */
    215 #  define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
    216 #  define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
    217 #  define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
    218 #  define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
    219 #  define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
    220 #  define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
    221 #  define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
    222 #  define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
    223 #  define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
    224 /* XXH64 */
    225 #  define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
    226 #  define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
    227 #  define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
    228 #  define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
    229 #  define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
    230 #  define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
    231 #  define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
    232 #  define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
    233 #  define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
    234 /* XXH3_64bits */
    235 #  define XXH3_64bits XXH_NAME2(XXH_NAMESPACE, XXH3_64bits)
    236 #  define XXH3_64bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSecret)
    237 #  define XXH3_64bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSeed)
    238 #  define XXH3_createState XXH_NAME2(XXH_NAMESPACE, XXH3_createState)
    239 #  define XXH3_freeState XXH_NAME2(XXH_NAMESPACE, XXH3_freeState)
    240 #  define XXH3_copyState XXH_NAME2(XXH_NAMESPACE, XXH3_copyState)
    241 #  define XXH3_64bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset)
    242 #  define XXH3_64bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSeed)
    243 #  define XXH3_64bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSecret)
    244 #  define XXH3_64bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_update)
    245 #  define XXH3_64bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_digest)
    246 #  define XXH3_generateSecret XXH_NAME2(XXH_NAMESPACE, XXH3_generateSecret)
    247 /* XXH3_128bits */
    248 #  define XXH128 XXH_NAME2(XXH_NAMESPACE, XXH128)
    249 #  define XXH3_128bits XXH_NAME2(XXH_NAMESPACE, XXH3_128bits)
    250 #  define XXH3_128bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSeed)
    251 #  define XXH3_128bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSecret)
    252 #  define XXH3_128bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset)
    253 #  define XXH3_128bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSeed)
    254 #  define XXH3_128bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSecret)
    255 #  define XXH3_128bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_update)
    256 #  define XXH3_128bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_digest)
    257 #  define XXH128_isEqual XXH_NAME2(XXH_NAMESPACE, XXH128_isEqual)
    258 #  define XXH128_cmp     XXH_NAME2(XXH_NAMESPACE, XXH128_cmp)
    259 #  define XXH128_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH128_canonicalFromHash)
    260 #  define XXH128_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH128_hashFromCanonical)
    261 #endif
    262 
    263 
    264 /* *************************************
    265 *  Version
    266 ***************************************/
    267 #define XXH_VERSION_MAJOR    0
    268 #define XXH_VERSION_MINOR    8
    269 #define XXH_VERSION_RELEASE  0
    270 #define XXH_VERSION_NUMBER  (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)
    271 
    272 /*!
    273  * @brief Obtains the xxHash version.
    274  *
    275  * This is only useful when xxHash is compiled as a shared library, as it is
    276  * independent of the version defined in the header.
    277  *
    278  * @return `XXH_VERSION_NUMBER` as of when the function was compiled.
    279  */
    280 XXH_PUBLIC_API unsigned XXH_versionNumber (void);
    281 
    282 
    283 /* ****************************
    284 *  Definitions
    285 ******************************/
    286 #include <stddef.h>   /* size_t */
    287 typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
    288 
    289 
    290 /*-**********************************************************************
    291 *  32-bit hash
    292 ************************************************************************/
    293 #if defined(XXH_DOXYGEN) /* Don't show <stdint.h> include */
    294 /*!
    295  * @brief An unsigned 32-bit integer.
    296  *
    297  * Not necessarily defined to `uint32_t` but functionally equivalent.
    298  */
    299 typedef uint32_t XXH32_hash_t;
    300 #elif !defined (__VMS) \
    301   && (defined (__cplusplus) \
    302   || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
    303 #   include <stdint.h>
    304     typedef uint32_t XXH32_hash_t;
    305 #else
    306 #   include <limits.h>
    307 #   if UINT_MAX == 0xFFFFFFFFUL
    308       typedef unsigned int XXH32_hash_t;
    309 #   else
    310 #     if ULONG_MAX == 0xFFFFFFFFUL
    311         typedef unsigned long XXH32_hash_t;
    312 #     else
    313 #       error "unsupported platform: need a 32-bit type"
    314 #     endif
    315 #   endif
    316 #endif
    317 
    318 /*!
    319  * @}
    320  *
    321  * @defgroup xxh32_family XXH32 family
    322  * @ingroup public
    323  * Contains functions used in the classic 32-bit xxHash algorithm.
    324  *
    325  * @note
    326  *   XXH32 is considered rather weak by today's standards.
    327  *   The @ref xxh3_family provides competitive speed for both 32-bit and 64-bit
    328  *   systems, and offers true 64/128 bit hash results. It provides a superior
    329  *   level of dispersion, and greatly reduces the risks of collisions.
    330  *
    331  * @see @ref xxh64_family, @ref xxh3_family : Other xxHash families
    332  * @see @ref xxh32_impl for implementation details
    333  * @{
    334  */
    335 
    336 /*!
    337  * @brief Calculates the 32-bit hash of @p input using xxHash32.
    338  *
    339  * Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark): 5.4 GB/s
    340  *
    341  * @param input The block of data to be hashed, at least @p length bytes in size.
    342  * @param length The length of @p input, in bytes.
    343  * @param seed The 32-bit seed to alter the hash's output predictably.
    344  *
    345  * @pre
    346  *   The memory between @p input and @p input + @p length must be valid,
    347  *   readable, contiguous memory. However, if @p length is `0`, @p input may be
    348  *   `NULL`. In C++, this also must be *TriviallyCopyable*.
    349  *
    350  * @return The calculated 32-bit hash value.
    351  *
    352  * @see
    353  *    XXH64(), XXH3_64bits_withSeed(), XXH3_128bits_withSeed(), XXH128():
    354  *    Direct equivalents for the other variants of xxHash.
    355  * @see
    356  *    XXH32_createState(), XXH32_update(), XXH32_digest(): Streaming version.
    357  */
    358 XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, XXH32_hash_t seed);
    359 
    360 /*!
    361  * Streaming functions generate the xxHash value from an incrememtal input.
    362  * This method is slower than single-call functions, due to state management.
    363  * For small inputs, prefer `XXH32()` and `XXH64()`, which are better optimized.
    364  *
    365  * An XXH state must first be allocated using `XXH*_createState()`.
    366  *
    367  * Start a new hash by initializing the state with a seed using `XXH*_reset()`.
    368  *
    369  * Then, feed the hash state by calling `XXH*_update()` as many times as necessary.
    370  *
    371  * The function returns an error code, with 0 meaning OK, and any other value
    372  * meaning there is an error.
    373  *
    374  * Finally, a hash value can be produced anytime, by using `XXH*_digest()`.
    375  * This function returns the nn-bits hash as an int or long long.
    376  *
    377  * It's still possible to continue inserting input into the hash state after a
    378  * digest, and generate new hash values later on by invoking `XXH*_digest()`.
    379  *
    380  * When done, release the state using `XXH*_freeState()`.
    381  *
    382  * Example code for incrementally hashing a file:
    383  * @code{.c}
    384  *    #include <stdio.h>
    385  *    #include <xxhash.h>
    386  *    #define BUFFER_SIZE 256
    387  *
    388  *    // Note: XXH64 and XXH3 use the same interface.
    389  *    XXH32_hash_t
    390  *    hashFile(FILE* stream)
    391  *    {
    392  *        XXH32_state_t* state;
    393  *        unsigned char buf[BUFFER_SIZE];
    394  *        size_t amt;
    395  *        XXH32_hash_t hash;
    396  *
    397  *        state = XXH32_createState();       // Create a state
    398  *        assert(state != NULL);             // Error check here
    399  *        XXH32_reset(state, 0xbaad5eed);    // Reset state with our seed
    400  *        while ((amt = fread(buf, 1, sizeof(buf), stream)) != 0) {
    401  *            XXH32_update(state, buf, amt); // Hash the file in chunks
    402  *        }
    403  *        hash = XXH32_digest(state);        // Finalize the hash
    404  *        XXH32_freeState(state);            // Clean up
    405  *        return hash;
    406  *    }
    407  * @endcode
    408  */
    409 
    410 /*!
    411  * @typedef struct XXH32_state_s XXH32_state_t
    412  * @brief The opaque state struct for the XXH32 streaming API.
    413  *
    414  * @see XXH32_state_s for details.
    415  */
    416 typedef struct XXH32_state_s XXH32_state_t;
    417 
    418 /*!
    419  * @brief Allocates an @ref XXH32_state_t.
    420  *
    421  * Must be freed with XXH32_freeState().
    422  * @return An allocated XXH32_state_t on success, `NULL` on failure.
    423  */
    424 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
    425 /*!
    426  * @brief Frees an @ref XXH32_state_t.
    427  *
    428  * Must be allocated with XXH32_createState().
    429  * @param statePtr A pointer to an @ref XXH32_state_t allocated with @ref XXH32_createState().
    430  * @return XXH_OK.
    431  */
    432 XXH_PUBLIC_API XXH_errorcode  XXH32_freeState(XXH32_state_t* statePtr);
    433 /*!
    434  * @brief Copies one @ref XXH32_state_t to another.
    435  *
    436  * @param dst_state The state to copy to.
    437  * @param src_state The state to copy from.
    438  * @pre
    439  *   @p dst_state and @p src_state must not be `NULL` and must not overlap.
    440  */
    441 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dst_state, const XXH32_state_t* src_state);
    442 
    443 /*!
    444  * @brief Resets an @ref XXH32_state_t to begin a new hash.
    445  *
    446  * This function resets and seeds a state. Call it before @ref XXH32_update().
    447  *
    448  * @param statePtr The state struct to reset.
    449  * @param seed The 32-bit seed to alter the hash result predictably.
    450  *
    451  * @pre
    452  *   @p statePtr must not be `NULL`.
    453  *
    454  * @return @ref XXH_OK on success, @ref XXH_ERROR on failure.
    455  */
    456 XXH_PUBLIC_API XXH_errorcode XXH32_reset  (XXH32_state_t* statePtr, XXH32_hash_t seed);
    457 
    458 /*!
    459  * @brief Consumes a block of @p input to an @ref XXH32_state_t.
    460  *
    461  * Call this to incrementally consume blocks of data.
    462  *
    463  * @param statePtr The state struct to update.
    464  * @param input The block of data to be hashed, at least @p length bytes in size.
    465  * @param length The length of @p input, in bytes.
    466  *
    467  * @pre
    468  *   @p statePtr must not be `NULL`.
    469  * @pre
    470  *   The memory between @p input and @p input + @p length must be valid,
    471  *   readable, contiguous memory. However, if @p length is `0`, @p input may be
    472  *   `NULL`. In C++, this also must be *TriviallyCopyable*.
    473  *
    474  * @return @ref XXH_OK on success, @ref XXH_ERROR on failure.
    475  */
    476 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
    477 
    478 /*!
    479  * @brief Returns the calculated hash value from an @ref XXH32_state_t.
    480  *
    481  * @note
    482  *   Calling XXH32_digest() will not affect @p statePtr, so you can update,
    483  *   digest, and update again.
    484  *
    485  * @param statePtr The state struct to calculate the hash from.
    486  *
    487  * @pre
    488  *  @p statePtr must not be `NULL`.
    489  *
    490  * @return The calculated xxHash32 value from that state.
    491  */
    492 XXH_PUBLIC_API XXH32_hash_t  XXH32_digest (const XXH32_state_t* statePtr);
    493 
    494 /*******   Canonical representation   *******/
    495 
    496 /*
    497  * The default return values from XXH functions are unsigned 32 and 64 bit
    498  * integers.
    499  * This the simplest and fastest format for further post-processing.
    500  *
    501  * However, this leaves open the question of what is the order on the byte level,
    502  * since little and big endian conventions will store the same number differently.
    503  *
    504  * The canonical representation settles this issue by mandating big-endian
    505  * convention, the same convention as human-readable numbers (large digits first).
    506  *
    507  * When writing hash values to storage, sending them over a network, or printing
    508  * them, it's highly recommended to use the canonical representation to ensure
    509  * portability across a wider range of systems, present and future.
    510  *
    511  * The following functions allow transformation of hash values to and from
    512  * canonical format.
    513  */
    514 
    515 /*!
    516  * @brief Canonical (big endian) representation of @ref XXH32_hash_t.
    517  */
    518 typedef struct {
    519     unsigned char digest[4]; /*!< Hash bytes, big endian */
    520 } XXH32_canonical_t;
    521 
    522 /*!
    523  * @brief Converts an @ref XXH32_hash_t to a big endian @ref XXH32_canonical_t.
    524  *
    525  * @param dst The @ref XXH32_canonical_t pointer to be stored to.
    526  * @param hash The @ref XXH32_hash_t to be converted.
    527  *
    528  * @pre
    529  *   @p dst must not be `NULL`.
    530  */
    531 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);
    532 
    533 /*!
    534  * @brief Converts an @ref XXH32_canonical_t to a native @ref XXH32_hash_t.
    535  *
    536  * @param src The @ref XXH32_canonical_t to convert.
    537  *
    538  * @pre
    539  *   @p src must not be `NULL`.
    540  *
    541  * @return The converted hash.
    542  */
    543 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
    544 
    545 
    546 /*!
    547  * @}
    548  * @ingroup public
    549  * @{
    550  */
    551 
    552 #ifndef XXH_NO_LONG_LONG
    553 /*-**********************************************************************
    554 *  64-bit hash
    555 ************************************************************************/
    556 #if defined(XXH_DOXYGEN) /* don't include <stdint.h> */
    557 /*!
    558  * @brief An unsigned 64-bit integer.
    559  *
    560  * Not necessarily defined to `uint64_t` but functionally equivalent.
    561  */
    562 typedef uint64_t XXH64_hash_t;
    563 #elif !defined (__VMS) \
    564   && (defined (__cplusplus) \
    565   || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
    566 #  include <stdint.h>
    567    typedef uint64_t XXH64_hash_t;
    568 #else
    569 #  include <limits.h>
    570 #  if defined(__LP64__) && ULONG_MAX == 0xFFFFFFFFFFFFFFFFULL
    571      /* LP64 ABI says uint64_t is unsigned long */
    572      typedef unsigned long XXH64_hash_t;
    573 #  else
    574      /* the following type must have a width of 64-bit */
    575      typedef unsigned long long XXH64_hash_t;
    576 #  endif
    577 #endif
    578 
    579 /*!
    580  * @}
    581  *
    582  * @defgroup xxh64_family XXH64 family
    583  * @ingroup public
    584  * @{
    585  * Contains functions used in the classic 64-bit xxHash algorithm.
    586  *
    587  * @note
    588  *   XXH3 provides competitive speed for both 32-bit and 64-bit systems,
    589  *   and offers true 64/128 bit hash results. It provides a superior level of
    590  *   dispersion, and greatly reduces the risks of collisions.
    591  */
    592 
    593 
    594 /*!
    595  * @brief Calculates the 64-bit hash of @p input using xxHash64.
    596  *
    597  * This function usually runs faster on 64-bit systems, but slower on 32-bit
    598  * systems (see benchmark).
    599  *
    600  * @param input The block of data to be hashed, at least @p length bytes in size.
    601  * @param length The length of @p input, in bytes.
    602  * @param seed The 64-bit seed to alter the hash's output predictably.
    603  *
    604  * @pre
    605  *   The memory between @p input and @p input + @p length must be valid,
    606  *   readable, contiguous memory. However, if @p length is `0`, @p input may be
    607  *   `NULL`. In C++, this also must be *TriviallyCopyable*.
    608  *
    609  * @return The calculated 64-bit hash.
    610  *
    611  * @see
    612  *    XXH32(), XXH3_64bits_withSeed(), XXH3_128bits_withSeed(), XXH128():
    613  *    Direct equivalents for the other variants of xxHash.
    614  * @see
    615  *    XXH64_createState(), XXH64_update(), XXH64_digest(): Streaming version.
    616  */
    617 XXH_PUBLIC_API XXH64_hash_t XXH64(const void* input, size_t length, XXH64_hash_t seed);
    618 
    619 /*******   Streaming   *******/
    620 /*!
    621  * @brief The opaque state struct for the XXH64 streaming API.
    622  *
    623  * @see XXH64_state_s for details.
    624  */
    625 typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */
    626 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);
    627 XXH_PUBLIC_API XXH_errorcode  XXH64_freeState(XXH64_state_t* statePtr);
    628 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dst_state, const XXH64_state_t* src_state);
    629 
    630 XXH_PUBLIC_API XXH_errorcode XXH64_reset  (XXH64_state_t* statePtr, XXH64_hash_t seed);
    631 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
    632 XXH_PUBLIC_API XXH64_hash_t  XXH64_digest (const XXH64_state_t* statePtr);
    633 
    634 /*******   Canonical representation   *******/
    635 typedef struct { unsigned char digest[sizeof(XXH64_hash_t)]; } XXH64_canonical_t;
    636 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
    637 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
    638 
    639 /*!
    640  * @}
    641  * ************************************************************************
    642  * @defgroup xxh3_family XXH3 family
    643  * @ingroup public
    644  * @{
    645  *
    646  * XXH3 is a more recent hash algorithm featuring:
    647  *  - Improved speed for both small and large inputs
    648  *  - True 64-bit and 128-bit outputs
    649  *  - SIMD acceleration
    650  *  - Improved 32-bit viability
    651  *
    652  * Speed analysis methodology is explained here:
    653  *
    654  *    https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html
    655  *
    656  * Compared to XXH64, expect XXH3 to run approximately
    657  * ~2x faster on large inputs and >3x faster on small ones,
    658  * exact differences vary depending on platform.
    659  *
    660  * XXH3's speed benefits greatly from SIMD and 64-bit arithmetic,
    661  * but does not require it.
    662  * Any 32-bit and 64-bit targets that can run XXH32 smoothly
    663  * can run XXH3 at competitive speeds, even without vector support.
    664  * Further details are explained in the implementation.
    665  *
    666  * Optimized implementations are provided for AVX512, AVX2, SSE2, NEON, POWER8,
    667  * ZVector and scalar targets. This can be controlled via the XXH_VECTOR macro.
    668  *
    669  * XXH3 implementation is portable:
    670  * it has a generic C90 formulation that can be compiled on any platform,
    671  * all implementations generage exactly the same hash value on all platforms.
    672  * Starting from v0.8.0, it's also labelled "stable", meaning that
    673  * any future version will also generate the same hash value.
    674  *
    675  * XXH3 offers 2 variants, _64bits and _128bits.
    676  *
    677  * When only 64 bits are needed, prefer invoking the _64bits variant, as it
    678  * reduces the amount of mixing, resulting in faster speed on small inputs.
    679  * It's also generally simpler to manipulate a scalar return type than a struct.
    680  *
    681  * The API supports one-shot hashing, streaming mode, and custom secrets.
    682  */
    683 
    684 /*-**********************************************************************
    685 *  XXH3 64-bit variant
    686 ************************************************************************/
    687 
    688 /* XXH3_64bits():
    689  * default 64-bit variant, using default secret and default seed of 0.
    690  * It's the fastest variant. */
    691 XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(const void* data, size_t len);
    692 
    693 /*
    694  * XXH3_64bits_withSeed():
    695  * This variant generates a custom secret on the fly
    696  * based on default secret altered using the `seed` value.
    697  * While this operation is decently fast, note that it's not completely free.
    698  * Note: seed==0 produces the same results as XXH3_64bits().
    699  */
    700 XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_withSeed(const void* data, size_t len, XXH64_hash_t seed);
    701 
    702 /*!
    703  * The bare minimum size for a custom secret.
    704  *
    705  * @see
    706  *  XXH3_64bits_withSecret(), XXH3_64bits_reset_withSecret(),
    707  *  XXH3_128bits_withSecret(), XXH3_128bits_reset_withSecret().
    708  */
    709 #define XXH3_SECRET_SIZE_MIN 136
    710 
    711 /*
    712  * XXH3_64bits_withSecret():
    713  * It's possible to provide any blob of bytes as a "secret" to generate the hash.
    714  * This makes it more difficult for an external actor to prepare an intentional collision.
    715  * The main condition is that secretSize *must* be large enough (>= XXH3_SECRET_SIZE_MIN).
    716  * However, the quality of produced hash values depends on secret's entropy.
    717  * Technically, the secret must look like a bunch of random bytes.
    718  * Avoid "trivial" or structured data such as repeated sequences or a text document.
    719  * Whenever unsure about the "randomness" of the blob of bytes,
    720  * consider relabelling it as a "custom seed" instead,
    721  * and employ "XXH3_generateSecret()" (see below)
    722  * to generate a high entropy secret derived from the custom seed.
    723  */
    724 XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_withSecret(const void* data, size_t len, const void* secret, size_t secretSize);
    725 
    726 
    727 /*******   Streaming   *******/
    728 /*
    729  * Streaming requires state maintenance.
    730  * This operation costs memory and CPU.
    731  * As a consequence, streaming is slower than one-shot hashing.
    732  * For better performance, prefer one-shot functions whenever applicable.
    733  */
    734 
    735 /*!
    736  * @brief The state struct for the XXH3 streaming API.
    737  *
    738  * @see XXH3_state_s for details.
    739  */
    740 typedef struct XXH3_state_s XXH3_state_t;
    741 XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void);
    742 XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr);
    743 XXH_PUBLIC_API void XXH3_copyState(XXH3_state_t* dst_state, const XXH3_state_t* src_state);
    744 
    745 /*
    746  * XXH3_64bits_reset():
    747  * Initialize with default parameters.
    748  * digest will be equivalent to `XXH3_64bits()`.
    749  */
    750 XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset(XXH3_state_t* statePtr);
    751 /*
    752  * XXH3_64bits_reset_withSeed():
    753  * Generate a custom secret from `seed`, and store it into `statePtr`.
    754  * digest will be equivalent to `XXH3_64bits_withSeed()`.
    755  */
    756 XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed);
    757 /*
    758  * XXH3_64bits_reset_withSecret():
    759  * `secret` is referenced, it _must outlive_ the hash streaming session.
    760  * Similar to one-shot API, `secretSize` must be >= `XXH3_SECRET_SIZE_MIN`,
    761  * and the quality of produced hash values depends on secret's entropy
    762  * (secret's content should look like a bunch of random bytes).
    763  * When in doubt about the randomness of a candidate `secret`,
    764  * consider employing `XXH3_generateSecret()` instead (see below).
    765  */
    766 XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize);
    767 
    768 XXH_PUBLIC_API XXH_errorcode XXH3_64bits_update (XXH3_state_t* statePtr, const void* input, size_t length);
    769 XXH_PUBLIC_API XXH64_hash_t  XXH3_64bits_digest (const XXH3_state_t* statePtr);
    770 
    771 /* note : canonical representation of XXH3 is the same as XXH64
    772  * since they both produce XXH64_hash_t values */
    773 
    774 
    775 /*-**********************************************************************
    776 *  XXH3 128-bit variant
    777 ************************************************************************/
    778 
    779 /*!
    780  * @brief The return value from 128-bit hashes.
    781  *
    782  * Stored in little endian order, although the fields themselves are in native
    783  * endianness.
    784  */
    785 typedef struct {
    786     XXH64_hash_t low64;   /*!< `value & 0xFFFFFFFFFFFFFFFF` */
    787     XXH64_hash_t high64;  /*!< `value >> 64` */
    788 } XXH128_hash_t;
    789 
    790 XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(const void* data, size_t len);
    791 XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_withSeed(const void* data, size_t len, XXH64_hash_t seed);
    792 XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_withSecret(const void* data, size_t len, const void* secret, size_t secretSize);
    793 
    794 /*******   Streaming   *******/
    795 /*
    796  * Streaming requires state maintenance.
    797  * This operation costs memory and CPU.
    798  * As a consequence, streaming is slower than one-shot hashing.
    799  * For better performance, prefer one-shot functions whenever applicable.
    800  *
    801  * XXH3_128bits uses the same XXH3_state_t as XXH3_64bits().
    802  * Use already declared XXH3_createState() and XXH3_freeState().
    803  *
    804  * All reset and streaming functions have same meaning as their 64-bit counterpart.
    805  */
    806 
    807 XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset(XXH3_state_t* statePtr);
    808 XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed);
    809 XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize);
    810 
    811 XXH_PUBLIC_API XXH_errorcode XXH3_128bits_update (XXH3_state_t* statePtr, const void* input, size_t length);
    812 XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (const XXH3_state_t* statePtr);
    813 
    814 /* Following helper functions make it possible to compare XXH128_hast_t values.
    815  * Since XXH128_hash_t is a structure, this capability is not offered by the language.
    816  * Note: For better performance, these functions can be inlined using XXH_INLINE_ALL */
    817 
    818 /*!
    819  * XXH128_isEqual():
    820  * Return: 1 if `h1` and `h2` are equal, 0 if they are not.
    821  */
    822 XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2);
    823 
    824 /*!
    825  * XXH128_cmp():
    826  *
    827  * This comparator is compatible with stdlib's `qsort()`/`bsearch()`.
    828  *
    829  * return: >0 if *h128_1  > *h128_2
    830  *         =0 if *h128_1 == *h128_2
    831  *         <0 if *h128_1  < *h128_2
    832  */
    833 XXH_PUBLIC_API int XXH128_cmp(const void* h128_1, const void* h128_2);
    834 
    835 
    836 /*******   Canonical representation   *******/
    837 typedef struct { unsigned char digest[sizeof(XXH128_hash_t)]; } XXH128_canonical_t;
    838 XXH_PUBLIC_API void XXH128_canonicalFromHash(XXH128_canonical_t* dst, XXH128_hash_t hash);
    839 XXH_PUBLIC_API XXH128_hash_t XXH128_hashFromCanonical(const XXH128_canonical_t* src);
    840 
    841 
    842 #endif  /* XXH_NO_LONG_LONG */
    843 
    844 /*!
    845  * @}
    846  */
    847 #endif /* XXHASH_H_5627135585666179 */
    848 
    849 
    850 
    851 #if defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742)
    852 #define XXHASH_H_STATIC_13879238742
    853 /* ****************************************************************************
    854  * This section contains declarations which are not guaranteed to remain stable.
    855  * They may change in future versions, becoming incompatible with a different
    856  * version of the library.
    857  * These declarations should only be used with static linking.
    858  * Never use them in association with dynamic linking!
    859  ***************************************************************************** */
    860 
    861 /*
    862  * These definitions are only present to allow static allocation
    863  * of XXH states, on stack or in a struct, for example.
    864  * Never **ever** access their members directly.
    865  */
    866 
    867 /*!
    868  * @internal
    869  * @brief Structure for XXH32 streaming API.
    870  *
    871  * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
    872  * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
    873  * an opaque type. This allows fields to safely be changed.
    874  *
    875  * Typedef'd to @ref XXH32_state_t.
    876  * Do not access the members of this struct directly.
    877  * @see XXH64_state_s, XXH3_state_s
    878  */
    879 struct XXH32_state_s {
    880    XXH32_hash_t total_len_32; /*!< Total length hashed, modulo 2^32 */
    881    XXH32_hash_t large_len;    /*!< Whether the hash is >= 16 (handles @ref total_len_32 overflow) */
    882    XXH32_hash_t v1;           /*!< First accumulator lane */
    883    XXH32_hash_t v2;           /*!< Second accumulator lane */
    884    XXH32_hash_t v3;           /*!< Third accumulator lane */
    885    XXH32_hash_t v4;           /*!< Fourth accumulator lane */
    886    XXH32_hash_t mem32[4];     /*!< Internal buffer for partial reads. Treated as unsigned char[16]. */
    887    XXH32_hash_t memsize;      /*!< Amount of data in @ref mem32 */
    888    XXH32_hash_t reserved;     /*!< Reserved field. Do not read or write to it, it may be removed. */
    889 };   /* typedef'd to XXH32_state_t */
    890 
    891 
    892 #ifndef XXH_NO_LONG_LONG  /* defined when there is no 64-bit support */
    893 
    894 /*!
    895  * @internal
    896  * @brief Structure for XXH64 streaming API.
    897  *
    898  * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
    899  * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
    900  * an opaque type. This allows fields to safely be changed.
    901  *
    902  * Typedef'd to @ref XXH64_state_t.
    903  * Do not access the members of this struct directly.
    904  * @see XXH32_state_s, XXH3_state_s
    905  */
    906 struct XXH64_state_s {
    907    XXH64_hash_t total_len;    /*!< Total length hashed. This is always 64-bit. */
    908    XXH64_hash_t v1;           /*!< First accumulator lane */
    909    XXH64_hash_t v2;           /*!< Second accumulator lane */
    910    XXH64_hash_t v3;           /*!< Third accumulator lane */
    911    XXH64_hash_t v4;           /*!< Fourth accumulator lane */
    912    XXH64_hash_t mem64[4];     /*!< Internal buffer for partial reads. Treated as unsigned char[32]. */
    913    XXH32_hash_t memsize;      /*!< Amount of data in @ref mem64 */
    914    XXH32_hash_t reserved32;   /*!< Reserved field, needed for padding anyways*/
    915    XXH64_hash_t reserved64;   /*!< Reserved field. Do not read or write to it, it may be removed. */
    916 };   /* typedef'd to XXH64_state_t */
    917 
    918 #if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)   /* C11+ */
    919 #  include <stdalign.h>
    920 #  define XXH_ALIGN(n)      alignas(n)
    921 #elif defined(__GNUC__)
    922 #  define XXH_ALIGN(n)      __attribute__ ((aligned(n)))
    923 #elif defined(_MSC_VER)
    924 #  define XXH_ALIGN(n)      __declspec(align(n))
    925 #else
    926 #  define XXH_ALIGN(n)   /* disabled */
    927 #endif
    928 
    929 /* Old GCC versions only accept the attribute after the type in structures. */
    930 #if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L))   /* C11+ */ \
    931     && defined(__GNUC__)
    932 #   define XXH_ALIGN_MEMBER(align, type) type XXH_ALIGN(align)
    933 #else
    934 #   define XXH_ALIGN_MEMBER(align, type) XXH_ALIGN(align) type
    935 #endif
    936 
    937 /*!
    938  * @brief The size of the internal XXH3 buffer.
    939  *
    940  * This is the optimal update size for incremental hashing.
    941  *
    942  * @see XXH3_64b_update(), XXH3_128b_update().
    943  */
    944 #define XXH3_INTERNALBUFFER_SIZE 256
    945 
    946 /*!
    947  * @brief Default size of the secret buffer (and @ref XXH3_kSecret).
    948  *
    949  * This is the size used in @ref XXH3_kSecret and the seeded functions.
    950  *
    951  * Not to be confused with @ref XXH3_SECRET_SIZE_MIN.
    952  */
    953 #define XXH3_SECRET_DEFAULT_SIZE 192
    954 
    955 /*!
    956  * @internal
    957  * @brief Structure for XXH3 streaming API.
    958  *
    959  * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
    960  * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
    961  * an opaque type. This allows fields to safely be changed.
    962  *
    963  * @note **This structure has a strict alignment requirement of 64 bytes.** Do
    964  * not allocate this with `malloc()` or `new`, it will not be sufficiently
    965  * aligned. Use @ref XXH3_createState() and @ref XXH3_freeState(), or stack
    966  * allocation.
    967  *
    968  * Typedef'd to @ref XXH3_state_t.
    969  * Do not access the members of this struct directly.
    970  *
    971  * @see XXH3_INITSTATE() for stack initialization.
    972  * @see XXH3_createState(), XXH3_freeState().
    973  * @see XXH32_state_s, XXH64_state_s
    974  */
    975 struct XXH3_state_s {
    976    XXH_ALIGN_MEMBER(64, XXH64_hash_t acc[8]);
    977        /*!< The 8 accumulators. Similar to `vN` in @ref XXH32_state_s::v1 and @ref XXH64_state_s */
    978    XXH_ALIGN_MEMBER(64, unsigned char customSecret[XXH3_SECRET_DEFAULT_SIZE]);
    979        /*!< Used to store a custom secret generated from a seed. */
    980    XXH_ALIGN_MEMBER(64, unsigned char buffer[XXH3_INTERNALBUFFER_SIZE]);
    981        /*!< The internal buffer. @see XXH32_state_s::mem32 */
    982    XXH32_hash_t bufferedSize;
    983        /*!< The amount of memory in @ref buffer, @see XXH32_state_s::memsize */
    984    XXH32_hash_t reserved32;
    985        /*!< Reserved field. Needed for padding on 64-bit. */
    986    size_t nbStripesSoFar;
    987        /*!< Number or stripes processed. */
    988    XXH64_hash_t totalLen;
    989        /*!< Total length hashed. 64-bit even on 32-bit targets. */
    990    size_t nbStripesPerBlock;
    991        /*!< Number of stripes per block. */
    992    size_t secretLimit;
    993        /*!< Size of @ref customSecret or @ref extSecret */
    994    XXH64_hash_t seed;
    995        /*!< Seed for _withSeed variants. Must be zero otherwise, @see XXH3_INITSTATE() */
    996    XXH64_hash_t reserved64;
    997        /*!< Reserved field. */
    998    const unsigned char* extSecret;
    999        /*!< Reference to an external secret for the _withSecret variants, NULL
   1000         *   for other variants. */
   1001    /* note: there may be some padding at the end due to alignment on 64 bytes */
   1002 }; /* typedef'd to XXH3_state_t */
   1003 
   1004 #undef XXH_ALIGN_MEMBER
   1005 
   1006 /*!
   1007  * @brief Initializes a stack-allocated `XXH3_state_s`.
   1008  *
   1009  * When the @ref XXH3_state_t structure is merely emplaced on stack,
   1010  * it should be initialized with XXH3_INITSTATE() or a memset()
   1011  * in case its first reset uses XXH3_NNbits_reset_withSeed().
   1012  * This init can be omitted if the first reset uses default or _withSecret mode.
   1013  * This operation isn't necessary when the state is created with XXH3_createState().
   1014  * Note that this doesn't prepare the state for a streaming operation,
   1015  * it's still necessary to use XXH3_NNbits_reset*() afterwards.
   1016  */
   1017 #define XXH3_INITSTATE(XXH3_state_ptr)   { (XXH3_state_ptr)->seed = 0; }
   1018 
   1019 
   1020 /* ===   Experimental API   === */
   1021 /* Symbols defined below must be considered tied to a specific library version. */
   1022 
   1023 /*
   1024  * XXH3_generateSecret():
   1025  *
   1026  * Derive a high-entropy secret from any user-defined content, named customSeed.
   1027  * The generated secret can be used in combination with `*_withSecret()` functions.
   1028  * The `_withSecret()` variants are useful to provide a higher level of protection than 64-bit seed,
   1029  * as it becomes much more difficult for an external actor to guess how to impact the calculation logic.
   1030  *
   1031  * The function accepts as input a custom seed of any length and any content,
   1032  * and derives from it a high-entropy secret of length XXH3_SECRET_DEFAULT_SIZE
   1033  * into an already allocated buffer secretBuffer.
   1034  * The generated secret is _always_ XXH_SECRET_DEFAULT_SIZE bytes long.
   1035  *
   1036  * The generated secret can then be used with any `*_withSecret()` variant.
   1037  * Functions `XXH3_128bits_withSecret()`, `XXH3_64bits_withSecret()`,
   1038  * `XXH3_128bits_reset_withSecret()` and `XXH3_64bits_reset_withSecret()`
   1039  * are part of this list. They all accept a `secret` parameter
   1040  * which must be very long for implementation reasons (>= XXH3_SECRET_SIZE_MIN)
   1041  * _and_ feature very high entropy (consist of random-looking bytes).
   1042  * These conditions can be a high bar to meet, so
   1043  * this function can be used to generate a secret of proper quality.
   1044  *
   1045  * customSeed can be anything. It can have any size, even small ones,
   1046  * and its content can be anything, even stupidly "low entropy" source such as a bunch of zeroes.
   1047  * The resulting `secret` will nonetheless provide all expected qualities.
   1048  *
   1049  * Supplying NULL as the customSeed copies the default secret into `secretBuffer`.
   1050  * When customSeedSize > 0, supplying NULL as customSeed is undefined behavior.
   1051  */
   1052 XXH_PUBLIC_API void XXH3_generateSecret(void* secretBuffer, const void* customSeed, size_t customSeedSize);
   1053 
   1054 
   1055 /* simple short-cut to pre-selected XXH3_128bits variant */
   1056 XXH_PUBLIC_API XXH128_hash_t XXH128(const void* data, size_t len, XXH64_hash_t seed);
   1057 
   1058 
   1059 #endif  /* XXH_NO_LONG_LONG */
   1060 #if defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)
   1061 #  define XXH_IMPLEMENTATION
   1062 #endif
   1063 
   1064 #endif  /* defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742) */
   1065 
   1066 
   1067 /* ======================================================================== */
   1068 /* ======================================================================== */
   1069 /* ======================================================================== */
   1070 
   1071 
   1072 /*-**********************************************************************
   1073  * xxHash implementation
   1074  *-**********************************************************************
   1075  * xxHash's implementation used to be hosted inside xxhash.c.
   1076  *
   1077  * However, inlining requires implementation to be visible to the compiler,
   1078  * hence be included alongside the header.
   1079  * Previously, implementation was hosted inside xxhash.c,
   1080  * which was then #included when inlining was activated.
   1081  * This construction created issues with a few build and install systems,
   1082  * as it required xxhash.c to be stored in /include directory.
   1083  *
   1084  * xxHash implementation is now directly integrated within xxhash.h.
   1085  * As a consequence, xxhash.c is no longer needed in /include.
   1086  *
   1087  * xxhash.c is still available and is still useful.
   1088  * In a "normal" setup, when xxhash is not inlined,
   1089  * xxhash.h only exposes the prototypes and public symbols,
   1090  * while xxhash.c can be built into an object file xxhash.o
   1091  * which can then be linked into the final binary.
   1092  ************************************************************************/
   1093 
   1094 #if ( defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API) \
   1095    || defined(XXH_IMPLEMENTATION) ) && !defined(XXH_IMPLEM_13a8737387)
   1096 #  define XXH_IMPLEM_13a8737387
   1097 
   1098 /* *************************************
   1099 *  Tuning parameters
   1100 ***************************************/
   1101 
   1102 /*!
   1103  * @defgroup tuning Tuning parameters
   1104  * @{
   1105  *
   1106  * Various macros to control xxHash's behavior.
   1107  */
   1108 #ifdef XXH_DOXYGEN
   1109 /*!
   1110  * @brief Define this to disable 64-bit code.
   1111  *
   1112  * Useful if only using the @ref xxh32_family and you have a strict C90 compiler.
   1113  */
   1114 #  define XXH_NO_LONG_LONG
   1115 #  undef XXH_NO_LONG_LONG /* don't actually */
   1116 /*!
   1117  * @brief Controls how unaligned memory is accessed.
   1118  *
   1119  * By default, access to unaligned memory is controlled by `memcpy()`, which is
   1120  * safe and portable.
   1121  *
   1122  * Unfortunately, on some target/compiler combinations, the generated assembly
   1123  * is sub-optimal.
   1124  *
   1125  * The below switch allow selection of a different access method
   1126  * in the search for improved performance.
   1127  *
   1128  * @par Possible options:
   1129  *
   1130  *  - `XXH_FORCE_MEMORY_ACCESS=0` (default): `memcpy`
   1131  *   @par
   1132  *     Use `memcpy()`. Safe and portable. Note that most modern compilers will
   1133  *     eliminate the function call and treat it as an unaligned access.
   1134  *
   1135  *  - `XXH_FORCE_MEMORY_ACCESS=1`: `__attribute__((packed))`
   1136  *   @par
   1137  *     Depends on compiler extensions and is therefore not portable.
   1138  *     This method is safe if your compiler supports it, and *generally* as
   1139  *     fast or faster than `memcpy`.
   1140  *
   1141  *  - `XXH_FORCE_MEMORY_ACCESS=2`: Direct cast
   1142  *  @par
   1143  *     Casts directly and dereferences. This method doesn't depend on the
   1144  *     compiler, but it violates the C standard as it directly dereferences an
   1145  *     unaligned pointer. It can generate buggy code on targets which do not
   1146  *     support unaligned memory accesses, but in some circumstances, it's the
   1147  *     only known way to get the most performance (example: GCC + ARMv6).
   1148  *
   1149  *  - `XXH_FORCE_MEMORY_ACCESS=3`: Byteshift
   1150  *  @par
   1151  *     Also portable. This can generate the best code on old compilers which don't
   1152  *     inline small `memcpy()` calls, and it might also be faster on big-endian
   1153  *     systems which lack a native byteswap instruction. However, some compilers
   1154  *     will emit literal byteshifts even if the target supports unaligned access.
   1155  *
   1156  *  .
   1157  *
   1158  * @warning
   1159  *   Methods 1 and 2 rely on implementation-defined behavior. Use these with
   1160  *   care, as what works on one compiler/platform/optimization level may cause
   1161  *   another to read garbage data or even crash.
   1162  *
   1163  * See https://stackoverflow.com/a/32095106/646947 for details.
   1164  *
   1165  * Prefer these methods in priority order (0 > 3 > 1 > 2)
   1166  */
   1167 #  define XXH_FORCE_MEMORY_ACCESS 0
   1168 /*!
   1169  * @def XXH_ACCEPT_NULL_INPUT_POINTER
   1170  * @brief Whether to add explicit `NULL` checks.
   1171  *
   1172  * If the input pointer is `NULL` and the length is non-zero, xxHash's default
   1173  * behavior is to dereference it, triggering a segfault.
   1174  *
   1175  * When this macro is enabled, xxHash actively checks the input for a null pointer.
   1176  * If it is, the result for null input pointers is the same as a zero-length input.
   1177  */
   1178 #  define XXH_ACCEPT_NULL_INPUT_POINTER 0
   1179 /*!
   1180  * @def XXH_FORCE_ALIGN_CHECK
   1181  * @brief If defined to non-zero, adds a special path for aligned inputs (XXH32()
   1182  * and XXH64() only).
   1183  *
   1184  * This is an important performance trick for architectures without decent
   1185  * unaligned memory access performance.
   1186  *
   1187  * It checks for input alignment, and when conditions are met, uses a "fast
   1188  * path" employing direct 32-bit/64-bit reads, resulting in _dramatically
   1189  * faster_ read speed.
   1190  *
   1191  * The check costs one initial branch per hash, which is generally negligible,
   1192  * but not zero.
   1193  *
   1194  * Moreover, it's not useful to generate an additional code path if memory
   1195  * access uses the same instruction for both aligned and unaligned
   1196  * adresses (e.g. x86 and aarch64).
   1197  *
   1198  * In these cases, the alignment check can be removed by setting this macro to 0.
   1199  * Then the code will always use unaligned memory access.
   1200  * Align check is automatically disabled on x86, x64 & arm64,
   1201  * which are platforms known to offer good unaligned memory accesses performance.
   1202  *
   1203  * This option does not affect XXH3 (only XXH32 and XXH64).
   1204  */
   1205 #  define XXH_FORCE_ALIGN_CHECK 0
   1206 
   1207 /*!
   1208  * @def XXH_NO_INLINE_HINTS
   1209  * @brief When non-zero, sets all functions to `static`.
   1210  *
   1211  * By default, xxHash tries to force the compiler to inline almost all internal
   1212  * functions.
   1213  *
   1214  * This can usually improve performance due to reduced jumping and improved
   1215  * constant folding, but significantly increases the size of the binary which
   1216  * might not be favorable.
   1217  *
   1218  * Additionally, sometimes the forced inlining can be detrimental to performance,
   1219  * depending on the architecture.
   1220  *
   1221  * XXH_NO_INLINE_HINTS marks all internal functions as static, giving the
   1222  * compiler full control on whether to inline or not.
   1223  *
   1224  * When not optimizing (-O0), optimizing for size (-Os, -Oz), or using
   1225  * -fno-inline with GCC or Clang, this will automatically be defined.
   1226  */
   1227 #  define XXH_NO_INLINE_HINTS 0
   1228 
   1229 /*!
   1230  * @def XXH_REROLL
   1231  * @brief Whether to reroll `XXH32_finalize` and `XXH64_finalize`.
   1232  *
   1233  * For performance, `XXH32_finalize` and `XXH64_finalize` use an unrolled loop
   1234  * in the form of a switch statement.
   1235  *
   1236  * This is not always desirable, as it generates larger code, and depending on
   1237  * the architecture, may even be slower
   1238  *
   1239  * This is automatically defined with `-Os`/`-Oz` on GCC and Clang.
   1240  */
   1241 #  define XXH_REROLL 0
   1242 
   1243 /*!
   1244  * @internal
   1245  * @brief Redefines old internal names.
   1246  *
   1247  * For compatibility with code that uses xxHash's internals before the names
   1248  * were changed to improve namespacing. There is no other reason to use this.
   1249  */
   1250 #  define XXH_OLD_NAMES
   1251 #  undef XXH_OLD_NAMES /* don't actually use, it is ugly. */
   1252 #endif /* XXH_DOXYGEN */
   1253 /*!
   1254  * @}
   1255  */
   1256 
   1257 #ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
   1258 #  if !defined(__clang__) && defined(__GNUC__) && defined(__ARM_FEATURE_UNALIGNED) && defined(__ARM_ARCH) && (__ARM_ARCH == 6)
   1259 #    define XXH_FORCE_MEMORY_ACCESS 2
   1260 #  elif !defined(__clang__) && ((defined(__INTEL_COMPILER) && !defined(_WIN32)) || \
   1261   (defined(__GNUC__) && (defined(__ARM_ARCH) && __ARM_ARCH >= 7)))
   1262 #    define XXH_FORCE_MEMORY_ACCESS 1
   1263 #  endif
   1264 #endif
   1265 
   1266 #ifndef XXH_ACCEPT_NULL_INPUT_POINTER   /* can be defined externally */
   1267 #  define XXH_ACCEPT_NULL_INPUT_POINTER 0
   1268 #endif
   1269 
   1270 #ifndef XXH_FORCE_ALIGN_CHECK  /* can be defined externally */
   1271 #  if defined(__i386)  || defined(__x86_64__) || defined(__aarch64__) \
   1272    || defined(_M_IX86) || defined(_M_X64)     || defined(_M_ARM64) /* visual */
   1273 #    define XXH_FORCE_ALIGN_CHECK 0
   1274 #  else
   1275 #    define XXH_FORCE_ALIGN_CHECK 1
   1276 #  endif
   1277 #endif
   1278 
   1279 #ifndef XXH_NO_INLINE_HINTS
   1280 #  if defined(__OPTIMIZE_SIZE__) /* -Os, -Oz */ \
   1281    || defined(__NO_INLINE__)     /* -O0, -fno-inline */
   1282 #    define XXH_NO_INLINE_HINTS 1
   1283 #  else
   1284 #    define XXH_NO_INLINE_HINTS 0
   1285 #  endif
   1286 #endif
   1287 
   1288 #ifndef XXH_REROLL
   1289 #  if defined(__OPTIMIZE_SIZE__)
   1290 #    define XXH_REROLL 1
   1291 #  else
   1292 #    define XXH_REROLL 0
   1293 #  endif
   1294 #endif
   1295 
   1296 /*!
   1297  * @defgroup impl Implementation
   1298  * @{
   1299  */
   1300 
   1301 
   1302 /* *************************************
   1303 *  Includes & Memory related functions
   1304 ***************************************/
   1305 /*
   1306  * Modify the local functions below should you wish to use
   1307  * different memory routines for malloc() and free()
   1308  */
   1309 #include <stdlib.h>
   1310 
   1311 /*!
   1312  * @internal
   1313  * @brief Modify this function to use a different routine than malloc().
   1314  */
   1315 static void* XXH_malloc(size_t s) { return malloc(s); }
   1316 
   1317 /*!
   1318  * @internal
   1319  * @brief Modify this function to use a different routine than free().
   1320  */
   1321 static void XXH_free(void* p) { free(p); }
   1322 
   1323 #include <string.h>
   1324 
   1325 /*!
   1326  * @internal
   1327  * @brief Modify this function to use a different routine than memcpy().
   1328  */
   1329 static void* XXH_memcpy(void* dest, const void* src, size_t size)
   1330 {
   1331     return memcpy(dest,src,size);
   1332 }
   1333 
   1334 #include <limits.h>   /* ULLONG_MAX */
   1335 
   1336 
   1337 /* *************************************
   1338 *  Compiler Specific Options
   1339 ***************************************/
   1340 #ifdef _MSC_VER /* Visual Studio warning fix */
   1341 #  pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
   1342 #endif
   1343 
   1344 #if XXH_NO_INLINE_HINTS  /* disable inlining hints */
   1345 #  if defined(__GNUC__)
   1346 #    define XXH_FORCE_INLINE static __attribute__((unused))
   1347 #  else
   1348 #    define XXH_FORCE_INLINE static
   1349 #  endif
   1350 #  define XXH_NO_INLINE static
   1351 /* enable inlining hints */
   1352 #elif defined(_MSC_VER)  /* Visual Studio */
   1353 #  define XXH_FORCE_INLINE static __forceinline
   1354 #  define XXH_NO_INLINE static __declspec(noinline)
   1355 #elif defined(__GNUC__)
   1356 #  define XXH_FORCE_INLINE static __inline__ __attribute__((always_inline, unused))
   1357 #  define XXH_NO_INLINE static __attribute__((noinline))
   1358 #elif defined (__cplusplus) \
   1359   || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L))   /* C99 */
   1360 #  define XXH_FORCE_INLINE static inline
   1361 #  define XXH_NO_INLINE static
   1362 #else
   1363 #  define XXH_FORCE_INLINE static
   1364 #  define XXH_NO_INLINE static
   1365 #endif
   1366 
   1367 
   1368 
   1369 /* *************************************
   1370 *  Debug
   1371 ***************************************/
   1372 /*!
   1373  * @ingroup tuning
   1374  * @def XXH_DEBUGLEVEL
   1375  * @brief Sets the debugging level.
   1376  *
   1377  * XXH_DEBUGLEVEL is expected to be defined externally, typically via the
   1378  * compiler's command line options. The value must be a number.
   1379  */
   1380 #ifndef XXH_DEBUGLEVEL
   1381 #  ifdef DEBUGLEVEL /* backwards compat */
   1382 #    define XXH_DEBUGLEVEL DEBUGLEVEL
   1383 #  else
   1384 #    define XXH_DEBUGLEVEL 0
   1385 #  endif
   1386 #endif
   1387 
   1388 #if (XXH_DEBUGLEVEL>=1)
   1389 #  include <assert.h>   /* note: can still be disabled with NDEBUG */
   1390 #  define XXH_ASSERT(c)   assert(c)
   1391 #else
   1392 #  define XXH_ASSERT(c)   ((void)0)
   1393 #endif
   1394 
   1395 /* note: use after variable declarations */
   1396 #define XXH_STATIC_ASSERT(c)  do { enum { XXH_sa = 1/(int)(!!(c)) }; } while (0)
   1397 
   1398 
   1399 /* *************************************
   1400 *  Basic Types
   1401 ***************************************/
   1402 #if !defined (__VMS) \
   1403  && (defined (__cplusplus) \
   1404  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
   1405 # include <stdint.h>
   1406   typedef uint8_t xxh_u8;
   1407 #else
   1408   typedef unsigned char xxh_u8;
   1409 #endif
   1410 typedef XXH32_hash_t xxh_u32;
   1411 
   1412 #ifdef XXH_OLD_NAMES
   1413 #  define BYTE xxh_u8
   1414 #  define U8   xxh_u8
   1415 #  define U32  xxh_u32
   1416 #endif
   1417 
   1418 /* ***   Memory access   *** */
   1419 
   1420 /*!
   1421  * @internal
   1422  * @fn xxh_u32 XXH_read32(const void* ptr)
   1423  * @brief Reads an unaligned 32-bit integer from @p ptr in native endianness.
   1424  *
   1425  * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
   1426  *
   1427  * @param ptr The pointer to read from.
   1428  * @return The 32-bit native endian integer from the bytes at @p ptr.
   1429  */
   1430 
   1431 /*!
   1432  * @internal
   1433  * @fn xxh_u32 XXH_readLE32(const void* ptr)
   1434  * @brief Reads an unaligned 32-bit little endian integer from @p ptr.
   1435  *
   1436  * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
   1437  *
   1438  * @param ptr The pointer to read from.
   1439  * @return The 32-bit little endian integer from the bytes at @p ptr.
   1440  */
   1441 
   1442 /*!
   1443  * @internal
   1444  * @fn xxh_u32 XXH_readBE32(const void* ptr)
   1445  * @brief Reads an unaligned 32-bit big endian integer from @p ptr.
   1446  *
   1447  * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
   1448  *
   1449  * @param ptr The pointer to read from.
   1450  * @return The 32-bit big endian integer from the bytes at @p ptr.
   1451  */
   1452 
   1453 /*!
   1454  * @internal
   1455  * @fn xxh_u32 XXH_readLE32_align(const void* ptr, XXH_alignment align)
   1456  * @brief Like @ref XXH_readLE32(), but has an option for aligned reads.
   1457  *
   1458  * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
   1459  * Note that when @ref XXH_FORCE_ALIGN_CHECK == 0, the @p align parameter is
   1460  * always @ref XXH_alignment::XXH_unaligned.
   1461  *
   1462  * @param ptr The pointer to read from.
   1463  * @param align Whether @p ptr is aligned.
   1464  * @pre
   1465  *   If @p align == @ref XXH_alignment::XXH_aligned, @p ptr must be 4 byte
   1466  *   aligned.
   1467  * @return The 32-bit little endian integer from the bytes at @p ptr.
   1468  */
   1469 
   1470 #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
   1471 /*
   1472  * Manual byteshift. Best for old compilers which don't inline memcpy.
   1473  * We actually directly use XXH_readLE32 and XXH_readBE32.
   1474  */
   1475 #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
   1476 
   1477 /*
   1478  * Force direct memory access. Only works on CPU which support unaligned memory
   1479  * access in hardware.
   1480  */
   1481 static xxh_u32 XXH_read32(const void* memPtr) { return *(const xxh_u32*) memPtr; }
   1482 
   1483 #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
   1484 
   1485 /*
   1486  * __pack instructions are safer but compiler specific, hence potentially
   1487  * problematic for some compilers.
   1488  *
   1489  * Currently only defined for GCC and ICC.
   1490  */
   1491 #ifdef XXH_OLD_NAMES
   1492 typedef union { xxh_u32 u32; } __attribute__((packed)) unalign;
   1493 #endif
   1494 static xxh_u32 XXH_read32(const void* ptr)
   1495 {
   1496     typedef union { xxh_u32 u32; } __attribute__((packed)) xxh_unalign;
   1497     return ((const xxh_unalign*)ptr)->u32;
   1498 }
   1499 
   1500 #else
   1501 
   1502 /*
   1503  * Portable and safe solution. Generally efficient.
   1504  * see: https://stackoverflow.com/a/32095106/646947
   1505  */
   1506 static xxh_u32 XXH_read32(const void* memPtr)
   1507 {
   1508     xxh_u32 val;
   1509     memcpy(&val, memPtr, sizeof(val));
   1510     return val;
   1511 }
   1512 
   1513 #endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
   1514 
   1515 
   1516 /* ***   Endianess   *** */
   1517 typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;
   1518 
   1519 /*!
   1520  * @ingroup tuning
   1521  * @def XXH_CPU_LITTLE_ENDIAN
   1522  * @brief Whether the target is little endian.
   1523  *
   1524  * Defined to 1 if the target is little endian, or 0 if it is big endian.
   1525  * It can be defined externally, for example on the compiler command line.
   1526  *
   1527  * If it is not defined, a runtime check (which is usually constant folded)
   1528  * is used instead.
   1529  *
   1530  * @note
   1531  *   This is not necessarily defined to an integer constant.
   1532  *
   1533  * @see XXH_isLittleEndian() for the runtime check.
   1534  */
   1535 #ifndef XXH_CPU_LITTLE_ENDIAN
   1536 /*
   1537  * Try to detect endianness automatically, to avoid the nonstandard behavior
   1538  * in `XXH_isLittleEndian()`
   1539  */
   1540 #  if defined(_WIN32) /* Windows is always little endian */ \
   1541      || defined(__LITTLE_ENDIAN__) \
   1542      || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
   1543 #    define XXH_CPU_LITTLE_ENDIAN 1
   1544 #  elif defined(__BIG_ENDIAN__) \
   1545      || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
   1546 #    define XXH_CPU_LITTLE_ENDIAN 0
   1547 #  else
   1548 /*!
   1549  * @internal
   1550  * @brief Runtime check for @ref XXH_CPU_LITTLE_ENDIAN.
   1551  *
   1552  * Most compilers will constant fold this.
   1553  */
   1554 static int XXH_isLittleEndian(void)
   1555 {
   1556     /*
   1557      * Portable and well-defined behavior.
   1558      * Don't use static: it is detrimental to performance.
   1559      */
   1560     const union { xxh_u32 u; xxh_u8 c[4]; } one = { 1 };
   1561     return one.c[0];
   1562 }
   1563 #   define XXH_CPU_LITTLE_ENDIAN   XXH_isLittleEndian()
   1564 #  endif
   1565 #endif
   1566 
   1567 
   1568 
   1569 
   1570 /* ****************************************
   1571 *  Compiler-specific Functions and Macros
   1572 ******************************************/
   1573 #define XXH_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
   1574 
   1575 #ifdef __has_builtin
   1576 #  define XXH_HAS_BUILTIN(x) __has_builtin(x)
   1577 #else
   1578 #  define XXH_HAS_BUILTIN(x) 0
   1579 #endif
   1580 
   1581 /*!
   1582  * @internal
   1583  * @def XXH_rotl32(x,r)
   1584  * @brief 32-bit rotate left.
   1585  *
   1586  * @param x The 32-bit integer to be rotated.
   1587  * @param r The number of bits to rotate.
   1588  * @pre
   1589  *   @p r > 0 && @p r < 32
   1590  * @note
   1591  *   @p x and @p r may be evaluated multiple times.
   1592  * @return The rotated result.
   1593  */
   1594 #if !defined(NO_CLANG_BUILTIN) && XXH_HAS_BUILTIN(__builtin_rotateleft32) \
   1595                                && XXH_HAS_BUILTIN(__builtin_rotateleft64)
   1596 #  define XXH_rotl32 __builtin_rotateleft32
   1597 #  define XXH_rotl64 __builtin_rotateleft64
   1598 /* Note: although _rotl exists for minGW (GCC under windows), performance seems poor */
   1599 #elif defined(_MSC_VER)
   1600 #  define XXH_rotl32(x,r) _rotl(x,r)
   1601 #  define XXH_rotl64(x,r) _rotl64(x,r)
   1602 #else
   1603 #  define XXH_rotl32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
   1604 #  define XXH_rotl64(x,r) (((x) << (r)) | ((x) >> (64 - (r))))
   1605 #endif
   1606 
   1607 /*!
   1608  * @internal
   1609  * @fn xxh_u32 XXH_swap32(xxh_u32 x)
   1610  * @brief A 32-bit byteswap.
   1611  *
   1612  * @param x The 32-bit integer to byteswap.
   1613  * @return @p x, byteswapped.
   1614  */
   1615 #if defined(_MSC_VER)     /* Visual Studio */
   1616 #  define XXH_swap32 _byteswap_ulong
   1617 #elif XXH_GCC_VERSION >= 403
   1618 #  define XXH_swap32 __builtin_bswap32
   1619 #else
   1620 static xxh_u32 XXH_swap32 (xxh_u32 x)
   1621 {
   1622     return  ((x << 24) & 0xff000000 ) |
   1623             ((x <<  8) & 0x00ff0000 ) |
   1624             ((x >>  8) & 0x0000ff00 ) |
   1625             ((x >> 24) & 0x000000ff );
   1626 }
   1627 #endif
   1628 
   1629 
   1630 /* ***************************
   1631 *  Memory reads
   1632 *****************************/
   1633 
   1634 /*!
   1635  * @internal
   1636  * @brief Enum to indicate whether a pointer is aligned.
   1637  */
   1638 typedef enum {
   1639     XXH_aligned,  /*!< Aligned */
   1640     XXH_unaligned /*!< Possibly unaligned */
   1641 } XXH_alignment;
   1642 
   1643 /*
   1644  * XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load.
   1645  *
   1646  * This is ideal for older compilers which don't inline memcpy.
   1647  */
   1648 #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
   1649 
   1650 XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* memPtr)
   1651 {
   1652     const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
   1653     return bytePtr[0]
   1654          | ((xxh_u32)bytePtr[1] << 8)
   1655          | ((xxh_u32)bytePtr[2] << 16)
   1656          | ((xxh_u32)bytePtr[3] << 24);
   1657 }
   1658 
   1659 XXH_FORCE_INLINE xxh_u32 XXH_readBE32(const void* memPtr)
   1660 {
   1661     const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
   1662     return bytePtr[3]
   1663          | ((xxh_u32)bytePtr[2] << 8)
   1664          | ((xxh_u32)bytePtr[1] << 16)
   1665          | ((xxh_u32)bytePtr[0] << 24);
   1666 }
   1667 
   1668 #else
   1669 XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* ptr)
   1670 {
   1671     return XXH_CPU_LITTLE_ENDIAN ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
   1672 }
   1673 
   1674 static xxh_u32 XXH_readBE32(const void* ptr)
   1675 {
   1676     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
   1677 }
   1678 #endif
   1679 
   1680 XXH_FORCE_INLINE xxh_u32
   1681 XXH_readLE32_align(const void* ptr, XXH_alignment align)
   1682 {
   1683     if (align==XXH_unaligned) {
   1684         return XXH_readLE32(ptr);
   1685     } else {
   1686         return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u32*)ptr : XXH_swap32(*(const xxh_u32*)ptr);
   1687     }
   1688 }
   1689 
   1690 
   1691 /* *************************************
   1692 *  Misc
   1693 ***************************************/
   1694 /*! @ingroup public */
   1695 XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
   1696 
   1697 
   1698 /* *******************************************************************
   1699 *  32-bit hash functions
   1700 *********************************************************************/
   1701 /*!
   1702  * @}
   1703  * @defgroup xxh32_impl XXH32 implementation
   1704  * @ingroup impl
   1705  * @{
   1706  */
   1707 static const xxh_u32 XXH_PRIME32_1 = 0x9E3779B1U;   /*!< 0b10011110001101110111100110110001 */
   1708 static const xxh_u32 XXH_PRIME32_2 = 0x85EBCA77U;   /*!< 0b10000101111010111100101001110111 */
   1709 static const xxh_u32 XXH_PRIME32_3 = 0xC2B2AE3DU;   /*!< 0b11000010101100101010111000111101 */
   1710 static const xxh_u32 XXH_PRIME32_4 = 0x27D4EB2FU;   /*!< 0b00100111110101001110101100101111 */
   1711 static const xxh_u32 XXH_PRIME32_5 = 0x165667B1U;   /*!< 0b00010110010101100110011110110001 */
   1712 
   1713 #ifdef XXH_OLD_NAMES
   1714 #  define PRIME32_1 XXH_PRIME32_1
   1715 #  define PRIME32_2 XXH_PRIME32_2
   1716 #  define PRIME32_3 XXH_PRIME32_3
   1717 #  define PRIME32_4 XXH_PRIME32_4
   1718 #  define PRIME32_5 XXH_PRIME32_5
   1719 #endif
   1720 
   1721 /*!
   1722  * @internal
   1723  * @brief Normal stripe processing routine.
   1724  *
   1725  * This shuffles the bits so that any bit from @p input impacts several bits in
   1726  * @p acc.
   1727  *
   1728  * @param acc The accumulator lane.
   1729  * @param input The stripe of input to mix.
   1730  * @return The mixed accumulator lane.
   1731  */
   1732 static xxh_u32 XXH32_round(xxh_u32 acc, xxh_u32 input)
   1733 {
   1734     acc += input * XXH_PRIME32_2;
   1735     acc  = XXH_rotl32(acc, 13);
   1736     acc *= XXH_PRIME32_1;
   1737 #if defined(__GNUC__) && defined(__SSE4_1__) && !defined(XXH_ENABLE_AUTOVECTORIZE)
   1738     /*
   1739      * UGLY HACK:
   1740      * This inline assembly hack forces acc into a normal register. This is the
   1741      * only thing that prevents GCC and Clang from autovectorizing the XXH32
   1742      * loop (pragmas and attributes don't work for some resason) without globally
   1743      * disabling SSE4.1.
   1744      *
   1745      * The reason we want to avoid vectorization is because despite working on
   1746      * 4 integers at a time, there are multiple factors slowing XXH32 down on
   1747      * SSE4:
   1748      * - There's a ridiculous amount of lag from pmulld (10 cycles of latency on
   1749      *   newer chips!) making it slightly slower to multiply four integers at
   1750      *   once compared to four integers independently. Even when pmulld was
   1751      *   fastest, Sandy/Ivy Bridge, it is still not worth it to go into SSE
   1752      *   just to multiply unless doing a long operation.
   1753      *
   1754      * - Four instructions are required to rotate,
   1755      *      movqda tmp,  v // not required with VEX encoding
   1756      *      pslld  tmp, 13 // tmp <<= 13
   1757      *      psrld  v,   19 // x >>= 19
   1758      *      por    v,  tmp // x |= tmp
   1759      *   compared to one for scalar:
   1760      *      roll   v, 13    // reliably fast across the board
   1761      *      shldl  v, v, 13 // Sandy Bridge and later prefer this for some reason
   1762      *
   1763      * - Instruction level parallelism is actually more beneficial here because
   1764      *   the SIMD actually serializes this operation: While v1 is rotating, v2
   1765      *   can load data, while v3 can multiply. SSE forces them to operate
   1766      *   together.
   1767      *
   1768      * How this hack works:
   1769      * __asm__(""       // Declare an assembly block but don't declare any instructions
   1770      *          :       // However, as an Input/Output Operand,
   1771      *          "+r"    // constrain a read/write operand (+) as a general purpose register (r).
   1772      *          (acc)   // and set acc as the operand
   1773      * );
   1774      *
   1775      * Because of the 'r', the compiler has promised that seed will be in a
   1776      * general purpose register and the '+' says that it will be 'read/write',
   1777      * so it has to assume it has changed. It is like volatile without all the
   1778      * loads and stores.
   1779      *
   1780      * Since the argument has to be in a normal register (not an SSE register),
   1781      * each time XXH32_round is called, it is impossible to vectorize.
   1782      */
   1783     __asm__("" : "+r" (acc));
   1784 #endif
   1785     return acc;
   1786 }
   1787 
   1788 /*!
   1789  * @internal
   1790  * @brief Mixes all bits to finalize the hash.
   1791  *
   1792  * The final mix ensures that all input bits have a chance to impact any bit in
   1793  * the output digest, resulting in an unbiased distribution.
   1794  *
   1795  * @param h32 The hash to avalanche.
   1796  * @return The avalanched hash.
   1797  */
   1798 static xxh_u32 XXH32_avalanche(xxh_u32 h32)
   1799 {
   1800     h32 ^= h32 >> 15;
   1801     h32 *= XXH_PRIME32_2;
   1802     h32 ^= h32 >> 13;
   1803     h32 *= XXH_PRIME32_3;
   1804     h32 ^= h32 >> 16;
   1805     return(h32);
   1806 }
   1807 
   1808 #define XXH_get32bits(p) XXH_readLE32_align(p, align)
   1809 
   1810 /*!
   1811  * @internal
   1812  * @brief Processes the last 0-15 bytes of @p ptr.
   1813  *
   1814  * There may be up to 15 bytes remaining to consume from the input.
   1815  * This final stage will digest them to ensure that all input bytes are present
   1816  * in the final mix.
   1817  *
   1818  * @param h32 The hash to finalize.
   1819  * @param ptr The pointer to the remaining input.
   1820  * @param len The remaining length, modulo 16.
   1821  * @param align Whether @p ptr is aligned.
   1822  * @return The finalized hash.
   1823  */
   1824 static xxh_u32
   1825 XXH32_finalize(xxh_u32 h32, const xxh_u8* ptr, size_t len, XXH_alignment align)
   1826 {
   1827 #define XXH_PROCESS1 do {                           \
   1828     h32 += (*ptr++) * XXH_PRIME32_5;                \
   1829     h32 = XXH_rotl32(h32, 11) * XXH_PRIME32_1;      \
   1830 } while (0)
   1831 
   1832 #define XXH_PROCESS4 do {                           \
   1833     h32 += XXH_get32bits(ptr) * XXH_PRIME32_3;      \
   1834     ptr += 4;                                   \
   1835     h32  = XXH_rotl32(h32, 17) * XXH_PRIME32_4;     \
   1836 } while (0)
   1837 
   1838     /* Compact rerolled version */
   1839     if (XXH_REROLL) {
   1840         len &= 15;
   1841         while (len >= 4) {
   1842             XXH_PROCESS4;
   1843             len -= 4;
   1844         }
   1845         while (len > 0) {
   1846             XXH_PROCESS1;
   1847             --len;
   1848         }
   1849         return XXH32_avalanche(h32);
   1850     } else {
   1851          switch(len&15) /* or switch(bEnd - p) */ {
   1852            case 12:      XXH_PROCESS4;
   1853                          /* fallthrough */
   1854            case 8:       XXH_PROCESS4;
   1855                          /* fallthrough */
   1856            case 4:       XXH_PROCESS4;
   1857                          return XXH32_avalanche(h32);
   1858 
   1859            case 13:      XXH_PROCESS4;
   1860                          /* fallthrough */
   1861            case 9:       XXH_PROCESS4;
   1862                          /* fallthrough */
   1863            case 5:       XXH_PROCESS4;
   1864                          XXH_PROCESS1;
   1865                          return XXH32_avalanche(h32);
   1866 
   1867            case 14:      XXH_PROCESS4;
   1868                          /* fallthrough */
   1869            case 10:      XXH_PROCESS4;
   1870                          /* fallthrough */
   1871            case 6:       XXH_PROCESS4;
   1872                          XXH_PROCESS1;
   1873                          XXH_PROCESS1;
   1874                          return XXH32_avalanche(h32);
   1875 
   1876            case 15:      XXH_PROCESS4;
   1877                          /* fallthrough */
   1878            case 11:      XXH_PROCESS4;
   1879                          /* fallthrough */
   1880            case 7:       XXH_PROCESS4;
   1881                          /* fallthrough */
   1882            case 3:       XXH_PROCESS1;
   1883                          /* fallthrough */
   1884            case 2:       XXH_PROCESS1;
   1885                          /* fallthrough */
   1886            case 1:       XXH_PROCESS1;
   1887                          /* fallthrough */
   1888            case 0:       return XXH32_avalanche(h32);
   1889         }
   1890         XXH_ASSERT(0);
   1891         return h32;   /* reaching this point is deemed impossible */
   1892     }
   1893 }
   1894 
   1895 #ifdef XXH_OLD_NAMES
   1896 #  define PROCESS1 XXH_PROCESS1
   1897 #  define PROCESS4 XXH_PROCESS4
   1898 #else
   1899 #  undef XXH_PROCESS1
   1900 #  undef XXH_PROCESS4
   1901 #endif
   1902 
   1903 /*!
   1904  * @internal
   1905  * @brief The implementation for @ref XXH32().
   1906  *
   1907  * @param input, len, seed Directly passed from @ref XXH32().
   1908  * @param align Whether @p input is aligned.
   1909  * @return The calculated hash.
   1910  */
   1911 XXH_FORCE_INLINE xxh_u32
   1912 XXH32_endian_align(const xxh_u8* input, size_t len, xxh_u32 seed, XXH_alignment align)
   1913 {
   1914     const xxh_u8* bEnd = input + len;
   1915     xxh_u32 h32;
   1916 
   1917 #if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
   1918     if (input==NULL) {
   1919         len=0;
   1920         bEnd=input=(const xxh_u8*)(size_t)16;
   1921     }
   1922 #endif
   1923 
   1924     if (len>=16) {
   1925         const xxh_u8* const limit = bEnd - 15;
   1926         xxh_u32 v1 = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
   1927         xxh_u32 v2 = seed + XXH_PRIME32_2;
   1928         xxh_u32 v3 = seed + 0;
   1929         xxh_u32 v4 = seed - XXH_PRIME32_1;
   1930 
   1931         do {
   1932             v1 = XXH32_round(v1, XXH_get32bits(input)); input += 4;
   1933             v2 = XXH32_round(v2, XXH_get32bits(input)); input += 4;
   1934             v3 = XXH32_round(v3, XXH_get32bits(input)); input += 4;
   1935             v4 = XXH32_round(v4, XXH_get32bits(input)); input += 4;
   1936         } while (input < limit);
   1937 
   1938         h32 = XXH_rotl32(v1, 1)  + XXH_rotl32(v2, 7)
   1939             + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
   1940     } else {
   1941         h32  = seed + XXH_PRIME32_5;
   1942     }
   1943 
   1944     h32 += (xxh_u32)len;
   1945 
   1946     return XXH32_finalize(h32, input, len&15, align);
   1947 }
   1948 
   1949 /*! @ingroup xxh32_family */
   1950 XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t len, XXH32_hash_t seed)
   1951 {
   1952 #if 0
   1953     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
   1954     XXH32_state_t state;
   1955     XXH32_reset(&state, seed);
   1956     XXH32_update(&state, (const xxh_u8*)input, len);
   1957     return XXH32_digest(&state);
   1958 #else
   1959     if (XXH_FORCE_ALIGN_CHECK) {
   1960         if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */
   1961             return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
   1962     }   }
   1963 
   1964     return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);
   1965 #endif
   1966 }
   1967 
   1968 
   1969 
   1970 /*******   Hash streaming   *******/
   1971 /*!
   1972  * @ingroup xxh32_family
   1973  */
   1974 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
   1975 {
   1976     return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
   1977 }
   1978 /*! @ingroup xxh32_family */
   1979 XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
   1980 {
   1981     XXH_free(statePtr);
   1982     return XXH_OK;
   1983 }
   1984 
   1985 /*! @ingroup xxh32_family */
   1986 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dstState, const XXH32_state_t* srcState)
   1987 {
   1988     memcpy(dstState, srcState, sizeof(*dstState));
   1989 }
   1990 
   1991 /*! @ingroup xxh32_family */
   1992 XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, XXH32_hash_t seed)
   1993 {
   1994     XXH32_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
   1995     memset(&state, 0, sizeof(state));
   1996     state.v1 = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
   1997     state.v2 = seed + XXH_PRIME32_2;
   1998     state.v3 = seed + 0;
   1999     state.v4 = seed - XXH_PRIME32_1;
   2000     /* do not write into reserved, planned to be removed in a future version */
   2001     memcpy(statePtr, &state, sizeof(state) - sizeof(state.reserved));
   2002     return XXH_OK;
   2003 }
   2004 
   2005 
   2006 /*! @ingroup xxh32_family */
   2007 XXH_PUBLIC_API XXH_errorcode
   2008 XXH32_update(XXH32_state_t* state, const void* input, size_t len)
   2009 {
   2010     if (input==NULL)
   2011 #if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
   2012         return XXH_OK;
   2013 #else
   2014         return XXH_ERROR;
   2015 #endif
   2016 
   2017     {   const xxh_u8* p = (const xxh_u8*)input;
   2018         const xxh_u8* const bEnd = p + len;
   2019 
   2020         state->total_len_32 += (XXH32_hash_t)len;
   2021         state->large_len |= (XXH32_hash_t)((len>=16) | (state->total_len_32>=16));
   2022 
   2023         if (state->memsize + len < 16)  {   /* fill in tmp buffer */
   2024             XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, len);
   2025             state->memsize += (XXH32_hash_t)len;
   2026             return XXH_OK;
   2027         }
   2028 
   2029         if (state->memsize) {   /* some data left from previous update */
   2030             XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, 16-state->memsize);
   2031             {   const xxh_u32* p32 = state->mem32;
   2032                 state->v1 = XXH32_round(state->v1, XXH_readLE32(p32)); p32++;
   2033                 state->v2 = XXH32_round(state->v2, XXH_readLE32(p32)); p32++;
   2034                 state->v3 = XXH32_round(state->v3, XXH_readLE32(p32)); p32++;
   2035                 state->v4 = XXH32_round(state->v4, XXH_readLE32(p32));
   2036             }
   2037             p += 16-state->memsize;
   2038             state->memsize = 0;
   2039         }
   2040 
   2041         if (p <= bEnd-16) {
   2042             const xxh_u8* const limit = bEnd - 16;
   2043             xxh_u32 v1 = state->v1;
   2044             xxh_u32 v2 = state->v2;
   2045             xxh_u32 v3 = state->v3;
   2046             xxh_u32 v4 = state->v4;
   2047 
   2048             do {
   2049                 v1 = XXH32_round(v1, XXH_readLE32(p)); p+=4;
   2050                 v2 = XXH32_round(v2, XXH_readLE32(p)); p+=4;
   2051                 v3 = XXH32_round(v3, XXH_readLE32(p)); p+=4;
   2052                 v4 = XXH32_round(v4, XXH_readLE32(p)); p+=4;
   2053             } while (p<=limit);
   2054 
   2055             state->v1 = v1;
   2056             state->v2 = v2;
   2057             state->v3 = v3;
   2058             state->v4 = v4;
   2059         }
   2060 
   2061         if (p < bEnd) {
   2062             XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
   2063             state->memsize = (unsigned)(bEnd-p);
   2064         }
   2065     }
   2066 
   2067     return XXH_OK;
   2068 }
   2069 
   2070 
   2071 /*! @ingroup xxh32_family */
   2072 XXH_PUBLIC_API XXH32_hash_t XXH32_digest(const XXH32_state_t* state)
   2073 {
   2074     xxh_u32 h32;
   2075 
   2076     if (state->large_len) {
   2077         h32 = XXH_rotl32(state->v1, 1)
   2078             + XXH_rotl32(state->v2, 7)
   2079             + XXH_rotl32(state->v3, 12)
   2080             + XXH_rotl32(state->v4, 18);
   2081     } else {
   2082         h32 = state->v3 /* == seed */ + XXH_PRIME32_5;
   2083     }
   2084 
   2085     h32 += state->total_len_32;
   2086 
   2087     return XXH32_finalize(h32, (const xxh_u8*)state->mem32, state->memsize, XXH_aligned);
   2088 }
   2089 
   2090 
   2091 /*******   Canonical representation   *******/
   2092 
   2093 /*!
   2094  * @ingroup xxh32_family
   2095  * The default return values from XXH functions are unsigned 32 and 64 bit
   2096  * integers.
   2097  *
   2098  * The canonical representation uses big endian convention, the same convention
   2099  * as human-readable numbers (large digits first).
   2100  *
   2101  * This way, hash values can be written into a file or buffer, remaining
   2102  * comparable across different systems.
   2103  *
   2104  * The following functions allow transformation of hash values to and from their
   2105  * canonical format.
   2106  */
   2107 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
   2108 {
   2109     XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
   2110     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
   2111     memcpy(dst, &hash, sizeof(*dst));
   2112 }
   2113 /*! @ingroup xxh32_family */
   2114 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
   2115 {
   2116     return XXH_readBE32(src);
   2117 }
   2118 
   2119 
   2120 #ifndef XXH_NO_LONG_LONG
   2121 
   2122 /* *******************************************************************
   2123 *  64-bit hash functions
   2124 *********************************************************************/
   2125 /*!
   2126  * @}
   2127  * @ingroup impl
   2128  * @{
   2129  */
   2130 /*******   Memory access   *******/
   2131 
   2132 typedef XXH64_hash_t xxh_u64;
   2133 
   2134 #ifdef XXH_OLD_NAMES
   2135 #  define U64 xxh_u64
   2136 #endif
   2137 
   2138 /*!
   2139  * XXH_REROLL_XXH64:
   2140  * Whether to reroll the XXH64_finalize() loop.
   2141  *
   2142  * Just like XXH32, we can unroll the XXH64_finalize() loop. This can be a
   2143  * performance gain on 64-bit hosts, as only one jump is required.
   2144  *
   2145  * However, on 32-bit hosts, because arithmetic needs to be done with two 32-bit
   2146  * registers, and 64-bit arithmetic needs to be simulated, it isn't beneficial
   2147  * to unroll. The code becomes ridiculously large (the largest function in the
   2148  * binary on i386!), and rerolling it saves anywhere from 3kB to 20kB. It is
   2149  * also slightly faster because it fits into cache better and is more likely
   2150  * to be inlined by the compiler.
   2151  *
   2152  * If XXH_REROLL is defined, this is ignored and the loop is always rerolled.
   2153  */
   2154 #ifndef XXH_REROLL_XXH64
   2155 #  if (defined(__ILP32__) || defined(_ILP32)) /* ILP32 is often defined on 32-bit GCC family */ \
   2156    || !(defined(__x86_64__) || defined(_M_X64) || defined(_M_AMD64) /* x86-64 */ \
   2157      || defined(_M_ARM64) || defined(__aarch64__) || defined(__arm64__) /* aarch64 */ \
   2158      || defined(__PPC64__) || defined(__PPC64LE__) || defined(__ppc64__) || defined(__powerpc64__) /* ppc64 */ \
   2159      || defined(__mips64__) || defined(__mips64)) /* mips64 */ \
   2160    || (!defined(SIZE_MAX) || SIZE_MAX < ULLONG_MAX) /* check limits */
   2161 #    define XXH_REROLL_XXH64 1
   2162 #  else
   2163 #    define XXH_REROLL_XXH64 0
   2164 #  endif
   2165 #endif /* !defined(XXH_REROLL_XXH64) */
   2166 
   2167 #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
   2168 /*
   2169  * Manual byteshift. Best for old compilers which don't inline memcpy.
   2170  * We actually directly use XXH_readLE64 and XXH_readBE64.
   2171  */
   2172 #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
   2173 
   2174 /* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
   2175 static xxh_u64 XXH_read64(const void* memPtr)
   2176 {
   2177     return *(const xxh_u64*) memPtr;
   2178 }
   2179 
   2180 #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
   2181 
   2182 /*
   2183  * __pack instructions are safer, but compiler specific, hence potentially
   2184  * problematic for some compilers.
   2185  *
   2186  * Currently only defined for GCC and ICC.
   2187  */
   2188 #ifdef XXH_OLD_NAMES
   2189 typedef union { xxh_u32 u32; xxh_u64 u64; } __attribute__((packed)) unalign64;
   2190 #endif
   2191 static xxh_u64 XXH_read64(const void* ptr)
   2192 {
   2193     typedef union { xxh_u32 u32; xxh_u64 u64; } __attribute__((packed)) xxh_unalign64;
   2194     return ((const xxh_unalign64*)ptr)->u64;
   2195 }
   2196 
   2197 #else
   2198 
   2199 /*
   2200  * Portable and safe solution. Generally efficient.
   2201  * see: https://stackoverflow.com/a/32095106/646947
   2202  */
   2203 static xxh_u64 XXH_read64(const void* memPtr)
   2204 {
   2205     xxh_u64 val;
   2206     memcpy(&val, memPtr, sizeof(val));
   2207     return val;
   2208 }
   2209 
   2210 #endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
   2211 
   2212 #if defined(_MSC_VER)     /* Visual Studio */
   2213 #  define XXH_swap64 _byteswap_uint64
   2214 #elif XXH_GCC_VERSION >= 403
   2215 #  define XXH_swap64 __builtin_bswap64
   2216 #else
   2217 static xxh_u64 XXH_swap64(xxh_u64 x)
   2218 {
   2219     return  ((x << 56) & 0xff00000000000000ULL) |
   2220             ((x << 40) & 0x00ff000000000000ULL) |
   2221             ((x << 24) & 0x0000ff0000000000ULL) |
   2222             ((x << 8)  & 0x000000ff00000000ULL) |
   2223             ((x >> 8)  & 0x00000000ff000000ULL) |
   2224             ((x >> 24) & 0x0000000000ff0000ULL) |
   2225             ((x >> 40) & 0x000000000000ff00ULL) |
   2226             ((x >> 56) & 0x00000000000000ffULL);
   2227 }
   2228 #endif
   2229 
   2230 
   2231 /* XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load. */
   2232 #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
   2233 
   2234 XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* memPtr)
   2235 {
   2236     const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
   2237     return bytePtr[0]
   2238          | ((xxh_u64)bytePtr[1] << 8)
   2239          | ((xxh_u64)bytePtr[2] << 16)
   2240          | ((xxh_u64)bytePtr[3] << 24)
   2241          | ((xxh_u64)bytePtr[4] << 32)
   2242          | ((xxh_u64)bytePtr[5] << 40)
   2243          | ((xxh_u64)bytePtr[6] << 48)
   2244          | ((xxh_u64)bytePtr[7] << 56);
   2245 }
   2246 
   2247 XXH_FORCE_INLINE xxh_u64 XXH_readBE64(const void* memPtr)
   2248 {
   2249     const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
   2250     return bytePtr[7]
   2251          | ((xxh_u64)bytePtr[6] << 8)
   2252          | ((xxh_u64)bytePtr[5] << 16)
   2253          | ((xxh_u64)bytePtr[4] << 24)
   2254          | ((xxh_u64)bytePtr[3] << 32)
   2255          | ((xxh_u64)bytePtr[2] << 40)
   2256          | ((xxh_u64)bytePtr[1] << 48)
   2257          | ((xxh_u64)bytePtr[0] << 56);
   2258 }
   2259 
   2260 #else
   2261 XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* ptr)
   2262 {
   2263     return XXH_CPU_LITTLE_ENDIAN ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
   2264 }
   2265 
   2266 static xxh_u64 XXH_readBE64(const void* ptr)
   2267 {
   2268     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
   2269 }
   2270 #endif
   2271 
   2272 XXH_FORCE_INLINE xxh_u64
   2273 XXH_readLE64_align(const void* ptr, XXH_alignment align)
   2274 {
   2275     if (align==XXH_unaligned)
   2276         return XXH_readLE64(ptr);
   2277     else
   2278         return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u64*)ptr : XXH_swap64(*(const xxh_u64*)ptr);
   2279 }
   2280 
   2281 
   2282 /*******   xxh64   *******/
   2283 /*!
   2284  * @}
   2285  * @defgroup xxh64_impl XXH64 implementation
   2286  * @ingroup impl
   2287  * @{
   2288  */
   2289 static const xxh_u64 XXH_PRIME64_1 = 0x9E3779B185EBCA87ULL;   /*!< 0b1001111000110111011110011011000110000101111010111100101010000111 */
   2290 static const xxh_u64 XXH_PRIME64_2 = 0xC2B2AE3D27D4EB4FULL;   /*!< 0b1100001010110010101011100011110100100111110101001110101101001111 */
   2291 static const xxh_u64 XXH_PRIME64_3 = 0x165667B19E3779F9ULL;   /*!< 0b0001011001010110011001111011000110011110001101110111100111111001 */
   2292 static const xxh_u64 XXH_PRIME64_4 = 0x85EBCA77C2B2AE63ULL;   /*!< 0b1000010111101011110010100111011111000010101100101010111001100011 */
   2293 static const xxh_u64 XXH_PRIME64_5 = 0x27D4EB2F165667C5ULL;   /*!< 0b0010011111010100111010110010111100010110010101100110011111000101 */
   2294 
   2295 #ifdef XXH_OLD_NAMES
   2296 #  define PRIME64_1 XXH_PRIME64_1
   2297 #  define PRIME64_2 XXH_PRIME64_2
   2298 #  define PRIME64_3 XXH_PRIME64_3
   2299 #  define PRIME64_4 XXH_PRIME64_4
   2300 #  define PRIME64_5 XXH_PRIME64_5
   2301 #endif
   2302 
   2303 static xxh_u64 XXH64_round(xxh_u64 acc, xxh_u64 input)
   2304 {
   2305     acc += input * XXH_PRIME64_2;
   2306     acc  = XXH_rotl64(acc, 31);
   2307     acc *= XXH_PRIME64_1;
   2308     return acc;
   2309 }
   2310 
   2311 static xxh_u64 XXH64_mergeRound(xxh_u64 acc, xxh_u64 val)
   2312 {
   2313     val  = XXH64_round(0, val);
   2314     acc ^= val;
   2315     acc  = acc * XXH_PRIME64_1 + XXH_PRIME64_4;
   2316     return acc;
   2317 }
   2318 
   2319 static xxh_u64 XXH64_avalanche(xxh_u64 h64)
   2320 {
   2321     h64 ^= h64 >> 33;
   2322     h64 *= XXH_PRIME64_2;
   2323     h64 ^= h64 >> 29;
   2324     h64 *= XXH_PRIME64_3;
   2325     h64 ^= h64 >> 32;
   2326     return h64;
   2327 }
   2328 
   2329 
   2330 #define XXH_get64bits(p) XXH_readLE64_align(p, align)
   2331 
   2332 static xxh_u64
   2333 XXH64_finalize(xxh_u64 h64, const xxh_u8* ptr, size_t len, XXH_alignment align)
   2334 {
   2335 #define XXH_PROCESS1_64 do {                                   \
   2336     h64 ^= (*ptr++) * XXH_PRIME64_5;                           \
   2337     h64 = XXH_rotl64(h64, 11) * XXH_PRIME64_1;                 \
   2338 } while (0)
   2339 
   2340 #define XXH_PROCESS4_64 do {                                   \
   2341     h64 ^= (xxh_u64)(XXH_get32bits(ptr)) * XXH_PRIME64_1;      \
   2342     ptr += 4;                                              \
   2343     h64 = XXH_rotl64(h64, 23) * XXH_PRIME64_2 + XXH_PRIME64_3;     \
   2344 } while (0)
   2345 
   2346 #define XXH_PROCESS8_64 do {                                   \
   2347     xxh_u64 const k1 = XXH64_round(0, XXH_get64bits(ptr)); \
   2348     ptr += 8;                                              \
   2349     h64 ^= k1;                                             \
   2350     h64  = XXH_rotl64(h64,27) * XXH_PRIME64_1 + XXH_PRIME64_4;     \
   2351 } while (0)
   2352 
   2353     /* Rerolled version for 32-bit targets is faster and much smaller. */
   2354     if (XXH_REROLL || XXH_REROLL_XXH64) {
   2355         len &= 31;
   2356         while (len >= 8) {
   2357             XXH_PROCESS8_64;
   2358             len -= 8;
   2359         }
   2360         if (len >= 4) {
   2361             XXH_PROCESS4_64;
   2362             len -= 4;
   2363         }
   2364         while (len > 0) {
   2365             XXH_PROCESS1_64;
   2366             --len;
   2367         }
   2368          return  XXH64_avalanche(h64);
   2369     } else {
   2370         switch(len & 31) {
   2371            case 24: XXH_PROCESS8_64;
   2372                          /* fallthrough */
   2373            case 16: XXH_PROCESS8_64;
   2374                          /* fallthrough */
   2375            case  8: XXH_PROCESS8_64;
   2376                     return XXH64_avalanche(h64);
   2377 
   2378            case 28: XXH_PROCESS8_64;
   2379                          /* fallthrough */
   2380            case 20: XXH_PROCESS8_64;
   2381                          /* fallthrough */
   2382            case 12: XXH_PROCESS8_64;
   2383                          /* fallthrough */
   2384            case  4: XXH_PROCESS4_64;
   2385                     return XXH64_avalanche(h64);
   2386 
   2387            case 25: XXH_PROCESS8_64;
   2388                          /* fallthrough */
   2389            case 17: XXH_PROCESS8_64;
   2390                          /* fallthrough */
   2391            case  9: XXH_PROCESS8_64;
   2392                     XXH_PROCESS1_64;
   2393                     return XXH64_avalanche(h64);
   2394 
   2395            case 29: XXH_PROCESS8_64;
   2396                          /* fallthrough */
   2397            case 21: XXH_PROCESS8_64;
   2398                          /* fallthrough */
   2399            case 13: XXH_PROCESS8_64;
   2400                          /* fallthrough */
   2401            case  5: XXH_PROCESS4_64;
   2402                     XXH_PROCESS1_64;
   2403                     return XXH64_avalanche(h64);
   2404 
   2405            case 26: XXH_PROCESS8_64;
   2406                          /* fallthrough */
   2407            case 18: XXH_PROCESS8_64;
   2408                          /* fallthrough */
   2409            case 10: XXH_PROCESS8_64;
   2410                     XXH_PROCESS1_64;
   2411                     XXH_PROCESS1_64;
   2412                     return XXH64_avalanche(h64);
   2413 
   2414            case 30: XXH_PROCESS8_64;
   2415                          /* fallthrough */
   2416            case 22: XXH_PROCESS8_64;
   2417                          /* fallthrough */
   2418            case 14: XXH_PROCESS8_64;
   2419                          /* fallthrough */
   2420            case  6: XXH_PROCESS4_64;
   2421                     XXH_PROCESS1_64;
   2422                     XXH_PROCESS1_64;
   2423                     return XXH64_avalanche(h64);
   2424 
   2425            case 27: XXH_PROCESS8_64;
   2426                          /* fallthrough */
   2427            case 19: XXH_PROCESS8_64;
   2428                          /* fallthrough */
   2429            case 11: XXH_PROCESS8_64;
   2430                     XXH_PROCESS1_64;
   2431                     XXH_PROCESS1_64;
   2432                     XXH_PROCESS1_64;
   2433                     return XXH64_avalanche(h64);
   2434 
   2435            case 31: XXH_PROCESS8_64;
   2436                          /* fallthrough */
   2437            case 23: XXH_PROCESS8_64;
   2438                          /* fallthrough */
   2439            case 15: XXH_PROCESS8_64;
   2440                          /* fallthrough */
   2441            case  7: XXH_PROCESS4_64;
   2442                          /* fallthrough */
   2443            case  3: XXH_PROCESS1_64;
   2444                          /* fallthrough */
   2445            case  2: XXH_PROCESS1_64;
   2446                          /* fallthrough */
   2447            case  1: XXH_PROCESS1_64;
   2448                          /* fallthrough */
   2449            case  0: return XXH64_avalanche(h64);
   2450         }
   2451     }
   2452     /* impossible to reach */
   2453     XXH_ASSERT(0);
   2454     return 0;  /* unreachable, but some compilers complain without it */
   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     const xxh_u8* bEnd = input + len;
   2471     xxh_u64 h64;
   2472 
   2473 #if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
   2474     if (input==NULL) {
   2475         len=0;
   2476         bEnd=input=(const xxh_u8*)(size_t)32;
   2477     }
   2478 #endif
   2479 
   2480     if (len>=32) {
   2481         const xxh_u8* const limit = bEnd - 32;
   2482         xxh_u64 v1 = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
   2483         xxh_u64 v2 = seed + XXH_PRIME64_2;
   2484         xxh_u64 v3 = seed + 0;
   2485         xxh_u64 v4 = seed - XXH_PRIME64_1;
   2486 
   2487         do {
   2488             v1 = XXH64_round(v1, XXH_get64bits(input)); input+=8;
   2489             v2 = XXH64_round(v2, XXH_get64bits(input)); input+=8;
   2490             v3 = XXH64_round(v3, XXH_get64bits(input)); input+=8;
   2491             v4 = XXH64_round(v4, XXH_get64bits(input)); input+=8;
   2492         } while (input<=limit);
   2493 
   2494         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
   2495         h64 = XXH64_mergeRound(h64, v1);
   2496         h64 = XXH64_mergeRound(h64, v2);
   2497         h64 = XXH64_mergeRound(h64, v3);
   2498         h64 = XXH64_mergeRound(h64, v4);
   2499 
   2500     } else {
   2501         h64  = seed + XXH_PRIME64_5;
   2502     }
   2503 
   2504     h64 += (xxh_u64) len;
   2505 
   2506     return XXH64_finalize(h64, input, len, align);
   2507 }
   2508 
   2509 
   2510 /*! @ingroup xxh64_family */
   2511 XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t len, XXH64_hash_t seed)
   2512 {
   2513 #if 0
   2514     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
   2515     XXH64_state_t state;
   2516     XXH64_reset(&state, seed);
   2517     XXH64_update(&state, (const xxh_u8*)input, len);
   2518     return XXH64_digest(&state);
   2519 #else
   2520     if (XXH_FORCE_ALIGN_CHECK) {
   2521         if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */
   2522             return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
   2523     }   }
   2524 
   2525     return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);
   2526 
   2527 #endif
   2528 }
   2529 
   2530 /*******   Hash Streaming   *******/
   2531 
   2532 /*! @ingroup xxh64_family*/
   2533 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
   2534 {
   2535     return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
   2536 }
   2537 /*! @ingroup xxh64_family */
   2538 XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
   2539 {
   2540     XXH_free(statePtr);
   2541     return XXH_OK;
   2542 }
   2543 
   2544 /*! @ingroup xxh64_family */
   2545 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dstState, const XXH64_state_t* srcState)
   2546 {
   2547     memcpy(dstState, srcState, sizeof(*dstState));
   2548 }
   2549 
   2550 /*! @ingroup xxh64_family */
   2551 XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, XXH64_hash_t seed)
   2552 {
   2553     XXH64_state_t state;   /* use a local state to memcpy() in order to avoid strict-aliasing warnings */
   2554     memset(&state, 0, sizeof(state));
   2555     state.v1 = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
   2556     state.v2 = seed + XXH_PRIME64_2;
   2557     state.v3 = seed + 0;
   2558     state.v4 = seed - XXH_PRIME64_1;
   2559      /* do not write into reserved64, might be removed in a future version */
   2560     memcpy(statePtr, &state, sizeof(state) - sizeof(state.reserved64));
   2561     return XXH_OK;
   2562 }
   2563 
   2564 /*! @ingroup xxh64_family */
   2565 XXH_PUBLIC_API XXH_errorcode
   2566 XXH64_update (XXH64_state_t* state, const void* input, size_t len)
   2567 {
   2568     if (input==NULL)
   2569 #if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
   2570         return XXH_OK;
   2571 #else
   2572         return XXH_ERROR;
   2573 #endif
   2574 
   2575     {   const xxh_u8* p = (const xxh_u8*)input;
   2576         const xxh_u8* const bEnd = p + len;
   2577 
   2578         state->total_len += len;
   2579 
   2580         if (state->memsize + len < 32) {  /* fill in tmp buffer */
   2581             XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, len);
   2582             state->memsize += (xxh_u32)len;
   2583             return XXH_OK;
   2584         }
   2585 
   2586         if (state->memsize) {   /* tmp buffer is full */
   2587             XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, 32-state->memsize);
   2588             state->v1 = XXH64_round(state->v1, XXH_readLE64(state->mem64+0));
   2589             state->v2 = XXH64_round(state->v2, XXH_readLE64(state->mem64+1));
   2590             state->v3 = XXH64_round(state->v3, XXH_readLE64(state->mem64+2));
   2591             state->v4 = XXH64_round(state->v4, XXH_readLE64(state->mem64+3));
   2592             p += 32 - state->memsize;
   2593             state->memsize = 0;
   2594         }
   2595 
   2596         if (p+32 <= bEnd) {
   2597             const xxh_u8* const limit = bEnd - 32;
   2598             xxh_u64 v1 = state->v1;
   2599             xxh_u64 v2 = state->v2;
   2600             xxh_u64 v3 = state->v3;
   2601             xxh_u64 v4 = state->v4;
   2602 
   2603             do {
   2604                 v1 = XXH64_round(v1, XXH_readLE64(p)); p+=8;
   2605                 v2 = XXH64_round(v2, XXH_readLE64(p)); p+=8;
   2606                 v3 = XXH64_round(v3, XXH_readLE64(p)); p+=8;
   2607                 v4 = XXH64_round(v4, XXH_readLE64(p)); p+=8;
   2608             } while (p<=limit);
   2609 
   2610             state->v1 = v1;
   2611             state->v2 = v2;
   2612             state->v3 = v3;
   2613             state->v4 = v4;
   2614         }
   2615 
   2616         if (p < bEnd) {
   2617             XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
   2618             state->memsize = (unsigned)(bEnd-p);
   2619         }
   2620     }
   2621 
   2622     return XXH_OK;
   2623 }
   2624 
   2625 
   2626 /*! @ingroup xxh64_family */
   2627 XXH_PUBLIC_API XXH64_hash_t XXH64_digest(const XXH64_state_t* state)
   2628 {
   2629     xxh_u64 h64;
   2630 
   2631     if (state->total_len >= 32) {
   2632         xxh_u64 const v1 = state->v1;
   2633         xxh_u64 const v2 = state->v2;
   2634         xxh_u64 const v3 = state->v3;
   2635         xxh_u64 const v4 = state->v4;
   2636 
   2637         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
   2638         h64 = XXH64_mergeRound(h64, v1);
   2639         h64 = XXH64_mergeRound(h64, v2);
   2640         h64 = XXH64_mergeRound(h64, v3);
   2641         h64 = XXH64_mergeRound(h64, v4);
   2642     } else {
   2643         h64  = state->v3 /*seed*/ + XXH_PRIME64_5;
   2644     }
   2645 
   2646     h64 += (xxh_u64) state->total_len;
   2647 
   2648     return XXH64_finalize(h64, (const xxh_u8*)state->mem64, (size_t)state->total_len, XXH_aligned);
   2649 }
   2650 
   2651 
   2652 /******* Canonical representation   *******/
   2653 
   2654 /*! @ingroup xxh64_family */
   2655 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
   2656 {
   2657     XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
   2658     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
   2659     memcpy(dst, &hash, sizeof(*dst));
   2660 }
   2661 
   2662 /*! @ingroup xxh64_family */
   2663 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
   2664 {
   2665     return XXH_readBE64(src);
   2666 }
   2667 
   2668 
   2669 
   2670 /* *********************************************************************
   2671 *  XXH3
   2672 *  New generation hash designed for speed on small keys and vectorization
   2673 ************************************************************************ */
   2674 /*!
   2675  * @}
   2676  * @defgroup xxh3_impl XXH3 implementation
   2677  * @ingroup impl
   2678  * @{
   2679  */
   2680 
   2681 /* ===   Compiler specifics   === */
   2682 
   2683 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* >= C99 */
   2684 #  define XXH_RESTRICT   restrict
   2685 #else
   2686 /* Note: it might be useful to define __restrict or __restrict__ for some C++ compilers */
   2687 #  define XXH_RESTRICT   /* disable */
   2688 #endif
   2689 
   2690 #if (defined(__GNUC__) && (__GNUC__ >= 3))  \
   2691   || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) \
   2692   || defined(__clang__)
   2693 #    define XXH_likely(x) __builtin_expect(x, 1)
   2694 #    define XXH_unlikely(x) __builtin_expect(x, 0)
   2695 #else
   2696 #    define XXH_likely(x) (x)
   2697 #    define XXH_unlikely(x) (x)
   2698 #endif
   2699 
   2700 #if defined(__GNUC__)
   2701 #  if defined(__AVX2__)
   2702 #    include <immintrin.h>
   2703 #  elif defined(__SSE2__)
   2704 #    include <emmintrin.h>
   2705 #  elif defined(__ARM_NEON__) || defined(__ARM_NEON)
   2706 #    define inline __inline__  /* circumvent a clang bug */
   2707 #    include <arm_neon.h>
   2708 #    undef inline
   2709 #  endif
   2710 #elif defined(_MSC_VER)
   2711 #  include <intrin.h>
   2712 #endif
   2713 
   2714 /*
   2715  * One goal of XXH3 is to make it fast on both 32-bit and 64-bit, while
   2716  * remaining a true 64-bit/128-bit hash function.
   2717  *
   2718  * This is done by prioritizing a subset of 64-bit operations that can be
   2719  * emulated without too many steps on the average 32-bit machine.
   2720  *
   2721  * For example, these two lines seem similar, and run equally fast on 64-bit:
   2722  *
   2723  *   xxh_u64 x;
   2724  *   x ^= (x >> 47); // good
   2725  *   x ^= (x >> 13); // bad
   2726  *
   2727  * However, to a 32-bit machine, there is a major difference.
   2728  *
   2729  * x ^= (x >> 47) looks like this:
   2730  *
   2731  *   x.lo ^= (x.hi >> (47 - 32));
   2732  *
   2733  * while x ^= (x >> 13) looks like this:
   2734  *
   2735  *   // note: funnel shifts are not usually cheap.
   2736  *   x.lo ^= (x.lo >> 13) | (x.hi << (32 - 13));
   2737  *   x.hi ^= (x.hi >> 13);
   2738  *
   2739  * The first one is significantly faster than the second, simply because the
   2740  * shift is larger than 32. This means:
   2741  *  - All the bits we need are in the upper 32 bits, so we can ignore the lower
   2742  *    32 bits in the shift.
   2743  *  - The shift result will always fit in the lower 32 bits, and therefore,
   2744  *    we can ignore the upper 32 bits in the xor.
   2745  *
   2746  * Thanks to this optimization, XXH3 only requires these features to be efficient:
   2747  *
   2748  *  - Usable unaligned access
   2749  *  - A 32-bit or 64-bit ALU
   2750  *      - If 32-bit, a decent ADC instruction
   2751  *  - A 32 or 64-bit multiply with a 64-bit result
   2752  *  - For the 128-bit variant, a decent byteswap helps short inputs.
   2753  *
   2754  * The first two are already required by XXH32, and almost all 32-bit and 64-bit
   2755  * platforms which can run XXH32 can run XXH3 efficiently.
   2756  *
   2757  * Thumb-1, the classic 16-bit only subset of ARM's instruction set, is one
   2758  * notable exception.
   2759  *
   2760  * First of all, Thumb-1 lacks support for the UMULL instruction which
   2761  * performs the important long multiply. This means numerous __aeabi_lmul
   2762  * calls.
   2763  *
   2764  * Second of all, the 8 functional registers are just not enough.
   2765  * Setup for __aeabi_lmul, byteshift loads, pointers, and all arithmetic need
   2766  * Lo registers, and this shuffling results in thousands more MOVs than A32.
   2767  *
   2768  * A32 and T32 don't have this limitation. They can access all 14 registers,
   2769  * do a 32->64 multiply with UMULL, and the flexible operand allowing free
   2770  * shifts is helpful, too.
   2771  *
   2772  * Therefore, we do a quick sanity check.
   2773  *
   2774  * If compiling Thumb-1 for a target which supports ARM instructions, we will
   2775  * emit a warning, as it is not a "sane" platform to compile for.
   2776  *
   2777  * Usually, if this happens, it is because of an accident and you probably need
   2778  * to specify -march, as you likely meant to compile for a newer architecture.
   2779  *
   2780  * Credit: large sections of the vectorial and asm source code paths
   2781  *         have been contributed by @easyaspi314
   2782  */
   2783 #if defined(__thumb__) && !defined(__thumb2__) && defined(__ARM_ARCH_ISA_ARM)
   2784 #   warning "XXH3 is highly inefficient without ARM or Thumb-2."
   2785 #endif
   2786 
   2787 /* ==========================================
   2788  * Vectorization detection
   2789  * ========================================== */
   2790 
   2791 #ifdef XXH_DOXYGEN
   2792 /*!
   2793  * @ingroup tuning
   2794  * @brief Overrides the vectorization implementation chosen for XXH3.
   2795  *
   2796  * Can be defined to 0 to disable SIMD or any of the values mentioned in
   2797  * @ref XXH_VECTOR_TYPE.
   2798  *
   2799  * If this is not defined, it uses predefined macros to determine the best
   2800  * implementation.
   2801  */
   2802 #  define XXH_VECTOR XXH_SCALAR
   2803 /*!
   2804  * @ingroup tuning
   2805  * @brief Possible values for @ref XXH_VECTOR.
   2806  *
   2807  * Note that these are actually implemented as macros.
   2808  *
   2809  * If this is not defined, it is detected automatically.
   2810  * @ref XXH_X86DISPATCH overrides this.
   2811  */
   2812 enum XXH_VECTOR_TYPE /* fake enum */ {
   2813     XXH_SCALAR = 0,  /*!< Portable scalar version */
   2814     XXH_SSE2   = 1,  /*!<
   2815                       * SSE2 for Pentium 4, Opteron, all x86_64.
   2816                       *
   2817                       * @note SSE2 is also guaranteed on Windows 10, macOS, and
   2818                       * Android x86.
   2819                       */
   2820     XXH_AVX2   = 2,  /*!< AVX2 for Haswell and Bulldozer */
   2821     XXH_AVX512 = 3,  /*!< AVX512 for Skylake and Icelake */
   2822     XXH_NEON   = 4,  /*!< NEON for most ARMv7-A and all AArch64 */
   2823     XXH_VSX    = 5,  /*!< VSX and ZVector for POWER8/z13 (64-bit) */
   2824 };
   2825 /*!
   2826  * @ingroup tuning
   2827  * @brief Selects the minimum alignment for XXH3's accumulators.
   2828  *
   2829  * When using SIMD, this should match the alignment reqired for said vector
   2830  * type, so, for example, 32 for AVX2.
   2831  *
   2832  * Default: Auto detected.
   2833  */
   2834 #  define XXH_ACC_ALIGN 8
   2835 #endif
   2836 
   2837 /* Actual definition */
   2838 #ifndef XXH_DOXYGEN
   2839 #  define XXH_SCALAR 0
   2840 #  define XXH_SSE2   1
   2841 #  define XXH_AVX2   2
   2842 #  define XXH_AVX512 3
   2843 #  define XXH_NEON   4
   2844 #  define XXH_VSX    5
   2845 #endif
   2846 
   2847 #ifndef XXH_VECTOR    /* can be defined on command line */
   2848 #  if defined(__AVX512F__)
   2849 #    define XXH_VECTOR XXH_AVX512
   2850 #  elif defined(__AVX2__)
   2851 #    define XXH_VECTOR XXH_AVX2
   2852 #  elif defined(__SSE2__) || defined(_M_AMD64) || defined(_M_X64) || (defined(_M_IX86_FP) && (_M_IX86_FP == 2))
   2853 #    define XXH_VECTOR XXH_SSE2
   2854 #  elif defined(__GNUC__) /* msvc support maybe later */ \
   2855   && (defined(__ARM_NEON__) || defined(__ARM_NEON)) \
   2856   && (defined(__LITTLE_ENDIAN__) /* We only support little endian NEON */ \
   2857     || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
   2858 #    define XXH_VECTOR XXH_NEON
   2859 #  elif (defined(__PPC64__) && defined(__POWER8_VECTOR__)) \
   2860      || (defined(__s390x__) && defined(__VEC__)) \
   2861      && defined(__GNUC__) /* TODO: IBM XL */
   2862 #    define XXH_VECTOR XXH_VSX
   2863 #  else
   2864 #    define XXH_VECTOR XXH_SCALAR
   2865 #  endif
   2866 #endif
   2867 
   2868 /*
   2869  * Controls the alignment of the accumulator,
   2870  * for compatibility with aligned vector loads, which are usually faster.
   2871  */
   2872 #ifndef XXH_ACC_ALIGN
   2873 #  if defined(XXH_X86DISPATCH)
   2874 #     define XXH_ACC_ALIGN 64  /* for compatibility with avx512 */
   2875 #  elif XXH_VECTOR == XXH_SCALAR  /* scalar */
   2876 #     define XXH_ACC_ALIGN 8
   2877 #  elif XXH_VECTOR == XXH_SSE2  /* sse2 */
   2878 #     define XXH_ACC_ALIGN 16
   2879 #  elif XXH_VECTOR == XXH_AVX2  /* avx2 */
   2880 #     define XXH_ACC_ALIGN 32
   2881 #  elif XXH_VECTOR == XXH_NEON  /* neon */
   2882 #     define XXH_ACC_ALIGN 16
   2883 #  elif XXH_VECTOR == XXH_VSX   /* vsx */
   2884 #     define XXH_ACC_ALIGN 16
   2885 #  elif XXH_VECTOR == XXH_AVX512  /* avx512 */
   2886 #     define XXH_ACC_ALIGN 64
   2887 #  endif
   2888 #endif
   2889 
   2890 #if defined(XXH_X86DISPATCH) || XXH_VECTOR == XXH_SSE2 \
   2891     || XXH_VECTOR == XXH_AVX2 || XXH_VECTOR == XXH_AVX512
   2892 #  define XXH_SEC_ALIGN XXH_ACC_ALIGN
   2893 #else
   2894 #  define XXH_SEC_ALIGN 8
   2895 #endif
   2896 
   2897 /*
   2898  * UGLY HACK:
   2899  * GCC usually generates the best code with -O3 for xxHash.
   2900  *
   2901  * However, when targeting AVX2, it is overzealous in its unrolling resulting
   2902  * in code roughly 3/4 the speed of Clang.
   2903  *
   2904  * There are other issues, such as GCC splitting _mm256_loadu_si256 into
   2905  * _mm_loadu_si128 + _mm256_inserti128_si256. This is an optimization which
   2906  * only applies to Sandy and Ivy Bridge... which don't even support AVX2.
   2907  *
   2908  * That is why when compiling the AVX2 version, it is recommended to use either
   2909  *   -O2 -mavx2 -march=haswell
   2910  * or
   2911  *   -O2 -mavx2 -mno-avx256-split-unaligned-load
   2912  * for decent performance, or to use Clang instead.
   2913  *
   2914  * Fortunately, we can control the first one with a pragma that forces GCC into
   2915  * -O2, but the other one we can't control without "failed to inline always
   2916  * inline function due to target mismatch" warnings.
   2917  */
   2918 #if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
   2919   && defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
   2920   && defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
   2921 #  pragma GCC push_options
   2922 #  pragma GCC optimize("-O2")
   2923 #endif
   2924 
   2925 
   2926 #if XXH_VECTOR == XXH_NEON
   2927 /*
   2928  * NEON's setup for vmlal_u32 is a little more complicated than it is on
   2929  * SSE2, AVX2, and VSX.
   2930  *
   2931  * While PMULUDQ and VMULEUW both perform a mask, VMLAL.U32 performs an upcast.
   2932  *
   2933  * To do the same operation, the 128-bit 'Q' register needs to be split into
   2934  * two 64-bit 'D' registers, performing this operation::
   2935  *
   2936  *   [                a                 |                 b                ]
   2937  *            |              '---------. .--------'                |
   2938  *            |                         x                          |
   2939  *            |              .---------' '--------.                |
   2940  *   [ a & 0xFFFFFFFF | b & 0xFFFFFFFF ],[    a >> 32     |     b >> 32    ]
   2941  *
   2942  * Due to significant changes in aarch64, the fastest method for aarch64 is
   2943  * completely different than the fastest method for ARMv7-A.
   2944  *
   2945  * ARMv7-A treats D registers as unions overlaying Q registers, so modifying
   2946  * D11 will modify the high half of Q5. This is similar to how modifying AH
   2947  * will only affect bits 8-15 of AX on x86.
   2948  *
   2949  * VZIP takes two registers, and puts even lanes in one register and odd lanes
   2950  * in the other.
   2951  *
   2952  * On ARMv7-A, this strangely modifies both parameters in place instead of
   2953  * taking the usual 3-operand form.
   2954  *
   2955  * Therefore, if we want to do this, we can simply use a D-form VZIP.32 on the
   2956  * lower and upper halves of the Q register to end up with the high and low
   2957  * halves where we want - all in one instruction.
   2958  *
   2959  *   vzip.32   d10, d11       @ d10 = { d10[0], d11[0] }; d11 = { d10[1], d11[1] }
   2960  *
   2961  * Unfortunately we need inline assembly for this: Instructions modifying two
   2962  * registers at once is not possible in GCC or Clang's IR, and they have to
   2963  * create a copy.
   2964  *
   2965  * aarch64 requires a different approach.
   2966  *
   2967  * In order to make it easier to write a decent compiler for aarch64, many
   2968  * quirks were removed, such as conditional execution.
   2969  *
   2970  * NEON was also affected by this.
   2971  *
   2972  * aarch64 cannot access the high bits of a Q-form register, and writes to a
   2973  * D-form register zero the high bits, similar to how writes to W-form scalar
   2974  * registers (or DWORD registers on x86_64) work.
   2975  *
   2976  * The formerly free vget_high intrinsics now require a vext (with a few
   2977  * exceptions)
   2978  *
   2979  * Additionally, VZIP was replaced by ZIP1 and ZIP2, which are the equivalent
   2980  * of PUNPCKL* and PUNPCKH* in SSE, respectively, in order to only modify one
   2981  * operand.
   2982  *
   2983  * The equivalent of the VZIP.32 on the lower and upper halves would be this
   2984  * mess:
   2985  *
   2986  *   ext     v2.4s, v0.4s, v0.4s, #2 // v2 = { v0[2], v0[3], v0[0], v0[1] }
   2987  *   zip1    v1.2s, v0.2s, v2.2s     // v1 = { v0[0], v2[0] }
   2988  *   zip2    v0.2s, v0.2s, v1.2s     // v0 = { v0[1], v2[1] }
   2989  *
   2990  * Instead, we use a literal downcast, vmovn_u64 (XTN), and vshrn_n_u64 (SHRN):
   2991  *
   2992  *   shrn    v1.2s, v0.2d, #32  // v1 = (uint32x2_t)(v0 >> 32);
   2993  *   xtn     v0.2s, v0.2d       // v0 = (uint32x2_t)(v0 & 0xFFFFFFFF);
   2994  *
   2995  * This is available on ARMv7-A, but is less efficient than a single VZIP.32.
   2996  */
   2997 
   2998 /*!
   2999  * Function-like macro:
   3000  * void XXH_SPLIT_IN_PLACE(uint64x2_t &in, uint32x2_t &outLo, uint32x2_t &outHi)
   3001  * {
   3002  *     outLo = (uint32x2_t)(in & 0xFFFFFFFF);
   3003  *     outHi = (uint32x2_t)(in >> 32);
   3004  *     in = UNDEFINED;
   3005  * }
   3006  */
   3007 # if !defined(XXH_NO_VZIP_HACK) /* define to disable */ \
   3008    && defined(__GNUC__) \
   3009    && !defined(__aarch64__) && !defined(__arm64__)
   3010 #  define XXH_SPLIT_IN_PLACE(in, outLo, outHi)                                              \
   3011     do {                                                                                    \
   3012       /* Undocumented GCC/Clang operand modifier: %e0 = lower D half, %f0 = upper D half */ \
   3013       /* https://github.com/gcc-mirror/gcc/blob/38cf91e5/gcc/config/arm/arm.c#L22486 */     \
   3014       /* https://github.com/llvm-mirror/llvm/blob/2c4ca683/lib/Target/ARM/ARMAsmPrinter.cpp#L399 */ \
   3015       __asm__("vzip.32  %e0, %f0" : "+w" (in));                                             \
   3016       (outLo) = vget_low_u32 (vreinterpretq_u32_u64(in));                                   \
   3017       (outHi) = vget_high_u32(vreinterpretq_u32_u64(in));                                   \
   3018    } while (0)
   3019 # else
   3020 #  define XXH_SPLIT_IN_PLACE(in, outLo, outHi)                                            \
   3021     do {                                                                                  \
   3022       (outLo) = vmovn_u64    (in);                                                        \
   3023       (outHi) = vshrn_n_u64  ((in), 32);                                                  \
   3024     } while (0)
   3025 # endif
   3026 #endif  /* XXH_VECTOR == XXH_NEON */
   3027 
   3028 /*
   3029  * VSX and Z Vector helpers.
   3030  *
   3031  * This is very messy, and any pull requests to clean this up are welcome.
   3032  *
   3033  * There are a lot of problems with supporting VSX and s390x, due to
   3034  * inconsistent intrinsics, spotty coverage, and multiple endiannesses.
   3035  */
   3036 #if XXH_VECTOR == XXH_VSX
   3037 #  if defined(__s390x__)
   3038 #    include <s390intrin.h>
   3039 #  else
   3040 /* gcc's altivec.h can have the unwanted consequence to unconditionally
   3041  * #define bool, vector, and pixel keywords,
   3042  * with bad consequences for programs already using these keywords for other purposes.
   3043  * The paragraph defining these macros is skipped when __APPLE_ALTIVEC__ is defined.
   3044  * __APPLE_ALTIVEC__ is _generally_ defined automatically by the compiler,
   3045  * but it seems that, in some cases, it isn't.
   3046  * Force the build macro to be defined, so that keywords are not altered.
   3047  */
   3048 #    if defined(__GNUC__) && !defined(__APPLE_ALTIVEC__)
   3049 #      define __APPLE_ALTIVEC__
   3050 #    endif
   3051 #    include <altivec.h>
   3052 #  endif
   3053 
   3054 typedef __vector unsigned long long xxh_u64x2;
   3055 typedef __vector unsigned char xxh_u8x16;
   3056 typedef __vector unsigned xxh_u32x4;
   3057 
   3058 # ifndef XXH_VSX_BE
   3059 #  if defined(__BIG_ENDIAN__) \
   3060   || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
   3061 #    define XXH_VSX_BE 1
   3062 #  elif defined(__VEC_ELEMENT_REG_ORDER__) && __VEC_ELEMENT_REG_ORDER__ == __ORDER_BIG_ENDIAN__
   3063 #    warning "-maltivec=be is not recommended. Please use native endianness."
   3064 #    define XXH_VSX_BE 1
   3065 #  else
   3066 #    define XXH_VSX_BE 0
   3067 #  endif
   3068 # endif /* !defined(XXH_VSX_BE) */
   3069 
   3070 # if XXH_VSX_BE
   3071 #  if defined(__POWER9_VECTOR__) || (defined(__clang__) && defined(__s390x__))
   3072 #    define XXH_vec_revb vec_revb
   3073 #  else
   3074 /*!
   3075  * A polyfill for POWER9's vec_revb().
   3076  */
   3077 XXH_FORCE_INLINE xxh_u64x2 XXH_vec_revb(xxh_u64x2 val)
   3078 {
   3079     xxh_u8x16 const vByteSwap = { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
   3080                                   0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08 };
   3081     return vec_perm(val, val, vByteSwap);
   3082 }
   3083 #  endif
   3084 # endif /* XXH_VSX_BE */
   3085 
   3086 /*!
   3087  * Performs an unaligned vector load and byte swaps it on big endian.
   3088  */
   3089 XXH_FORCE_INLINE xxh_u64x2 XXH_vec_loadu(const void *ptr)
   3090 {
   3091     xxh_u64x2 ret;
   3092     memcpy(&ret, ptr, sizeof(xxh_u64x2));
   3093 # if XXH_VSX_BE
   3094     ret = XXH_vec_revb(ret);
   3095 # endif
   3096     return ret;
   3097 }
   3098 
   3099 /*
   3100  * vec_mulo and vec_mule are very problematic intrinsics on PowerPC
   3101  *
   3102  * These intrinsics weren't added until GCC 8, despite existing for a while,
   3103  * and they are endian dependent. Also, their meaning swap depending on version.
   3104  * */
   3105 # if defined(__s390x__)
   3106  /* s390x is always big endian, no issue on this platform */
   3107 #  define XXH_vec_mulo vec_mulo
   3108 #  define XXH_vec_mule vec_mule
   3109 # elif defined(__clang__) && XXH_HAS_BUILTIN(__builtin_altivec_vmuleuw)
   3110 /* Clang has a better way to control this, we can just use the builtin which doesn't swap. */
   3111 #  define XXH_vec_mulo __builtin_altivec_vmulouw
   3112 #  define XXH_vec_mule __builtin_altivec_vmuleuw
   3113 # else
   3114 /* gcc needs inline assembly */
   3115 /* Adapted from https://github.com/google/highwayhash/blob/master/highwayhash/hh_vsx.h. */
   3116 XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mulo(xxh_u32x4 a, xxh_u32x4 b)
   3117 {
   3118     xxh_u64x2 result;
   3119     __asm__("vmulouw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
   3120     return result;
   3121 }
   3122 XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mule(xxh_u32x4 a, xxh_u32x4 b)
   3123 {
   3124     xxh_u64x2 result;
   3125     __asm__("vmuleuw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
   3126     return result;
   3127 }
   3128 # endif /* XXH_vec_mulo, XXH_vec_mule */
   3129 #endif /* XXH_VECTOR == XXH_VSX */
   3130 
   3131 
   3132 /* prefetch
   3133  * can be disabled, by declaring XXH_NO_PREFETCH build macro */
   3134 #if defined(XXH_NO_PREFETCH)
   3135 #  define XXH_PREFETCH(ptr)  (void)(ptr)  /* disabled */
   3136 #else
   3137 #  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_IX86))  /* _mm_prefetch() not defined outside of x86/x64 */
   3138 #    include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
   3139 #    define XXH_PREFETCH(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
   3140 #  elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
   3141 #    define XXH_PREFETCH(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
   3142 #  else
   3143 #    define XXH_PREFETCH(ptr) (void)(ptr)  /* disabled */
   3144 #  endif
   3145 #endif  /* XXH_NO_PREFETCH */
   3146 
   3147 
   3148 /* ==========================================
   3149  * XXH3 default settings
   3150  * ========================================== */
   3151 
   3152 #define XXH_SECRET_DEFAULT_SIZE 192   /* minimum XXH3_SECRET_SIZE_MIN */
   3153 
   3154 #if (XXH_SECRET_DEFAULT_SIZE < XXH3_SECRET_SIZE_MIN)
   3155 #  error "default keyset is not large enough"
   3156 #endif
   3157 
   3158 /*! Pseudorandom secret taken directly from FARSH. */
   3159 XXH_ALIGN(64) static const xxh_u8 XXH3_kSecret[XXH_SECRET_DEFAULT_SIZE] = {
   3160     0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c,
   3161     0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f,
   3162     0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,
   3163     0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c,
   3164     0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3,
   3165     0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,
   3166     0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d,
   3167     0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64,
   3168     0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,
   3169     0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e,
   3170     0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce,
   3171     0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,
   3172 };
   3173 
   3174 
   3175 #ifdef XXH_OLD_NAMES
   3176 #  define kSecret XXH3_kSecret
   3177 #endif
   3178 
   3179 #ifdef XXH_DOXYGEN
   3180 /*!
   3181  * @brief Calculates a 32-bit to 64-bit long multiply.
   3182  *
   3183  * Implemented as a macro.
   3184  *
   3185  * Wraps `__emulu` on MSVC x86 because it tends to call `__allmul` when it doesn't
   3186  * need to (but it shouldn't need to anyways, it is about 7 instructions to do
   3187  * a 64x64 multiply...). Since we know that this will _always_ emit `MULL`, we
   3188  * use that instead of the normal method.
   3189  *
   3190  * If you are compiling for platforms like Thumb-1 and don't have a better option,
   3191  * you may also want to write your own long multiply routine here.
   3192  *
   3193  * @param x, y Numbers to be multiplied
   3194  * @return 64-bit product of the low 32 bits of @p x and @p y.
   3195  */
   3196 XXH_FORCE_INLINE xxh_u64
   3197 XXH_mult32to64(xxh_u64 x, xxh_u64 y)
   3198 {
   3199    return (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF);
   3200 }
   3201 #elif defined(_MSC_VER) && defined(_M_IX86)
   3202 #    include <intrin.h>
   3203 #    define XXH_mult32to64(x, y) __emulu((unsigned)(x), (unsigned)(y))
   3204 #else
   3205 /*
   3206  * Downcast + upcast is usually better than masking on older compilers like
   3207  * GCC 4.2 (especially 32-bit ones), all without affecting newer compilers.
   3208  *
   3209  * The other method, (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF), will AND both operands
   3210  * and perform a full 64x64 multiply -- entirely redundant on 32-bit.
   3211  */
   3212 #    define XXH_mult32to64(x, y) ((xxh_u64)(xxh_u32)(x) * (xxh_u64)(xxh_u32)(y))
   3213 #endif
   3214 
   3215 /*!
   3216  * @brief Calculates a 64->128-bit long multiply.
   3217  *
   3218  * Uses `__uint128_t` and `_umul128` if available, otherwise uses a scalar
   3219  * version.
   3220  *
   3221  * @param lhs, rhs The 64-bit integers to be multiplied
   3222  * @return The 128-bit result represented in an @ref XXH128_hash_t.
   3223  */
   3224 static XXH128_hash_t
   3225 XXH_mult64to128(xxh_u64 lhs, xxh_u64 rhs)
   3226 {
   3227     /*
   3228      * GCC/Clang __uint128_t method.
   3229      *
   3230      * On most 64-bit targets, GCC and Clang define a __uint128_t type.
   3231      * This is usually the best way as it usually uses a native long 64-bit
   3232      * multiply, such as MULQ on x86_64 or MUL + UMULH on aarch64.
   3233      *
   3234      * Usually.
   3235      *
   3236      * Despite being a 32-bit platform, Clang (and emscripten) define this type
   3237      * despite not having the arithmetic for it. This results in a laggy
   3238      * compiler builtin call which calculates a full 128-bit multiply.
   3239      * In that case it is best to use the portable one.
   3240      * https://github.com/Cyan4973/xxHash/issues/211#issuecomment-515575677
   3241      */
   3242 #if defined(__GNUC__) && !defined(__wasm__) \
   3243     && defined(__SIZEOF_INT128__) \
   3244     || (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
   3245 
   3246     __uint128_t const product = (__uint128_t)lhs * (__uint128_t)rhs;
   3247     XXH128_hash_t r128;
   3248     r128.low64  = (xxh_u64)(product);
   3249     r128.high64 = (xxh_u64)(product >> 64);
   3250     return r128;
   3251 
   3252     /*
   3253      * MSVC for x64's _umul128 method.
   3254      *
   3255      * xxh_u64 _umul128(xxh_u64 Multiplier, xxh_u64 Multiplicand, xxh_u64 *HighProduct);
   3256      *
   3257      * This compiles to single operand MUL on x64.
   3258      */
   3259 #elif defined(_M_X64) || defined(_M_IA64)
   3260 
   3261 #ifndef _MSC_VER
   3262 #   pragma intrinsic(_umul128)
   3263 #endif
   3264     xxh_u64 product_high;
   3265     xxh_u64 const product_low = _umul128(lhs, rhs, &product_high);
   3266     XXH128_hash_t r128;
   3267     r128.low64  = product_low;
   3268     r128.high64 = product_high;
   3269     return r128;
   3270 
   3271 #else
   3272     /*
   3273      * Portable scalar method. Optimized for 32-bit and 64-bit ALUs.
   3274      *
   3275      * This is a fast and simple grade school multiply, which is shown below
   3276      * with base 10 arithmetic instead of base 0x100000000.
   3277      *
   3278      *           9 3 // D2 lhs = 93
   3279      *         x 7 5 // D2 rhs = 75
   3280      *     ----------
   3281      *           1 5 // D2 lo_lo = (93 % 10) * (75 % 10) = 15
   3282      *         4 5 | // D2 hi_lo = (93 / 10) * (75 % 10) = 45
   3283      *         2 1 | // D2 lo_hi = (93 % 10) * (75 / 10) = 21
   3284      *     + 6 3 | | // D2 hi_hi = (93 / 10) * (75 / 10) = 63
   3285      *     ---------
   3286      *         2 7 | // D2 cross = (15 / 10) + (45 % 10) + 21 = 27
   3287      *     + 6 7 | | // D2 upper = (27 / 10) + (45 / 10) + 63 = 67
   3288      *     ---------
   3289      *       6 9 7 5 // D4 res = (27 * 10) + (15 % 10) + (67 * 100) = 6975
   3290      *
   3291      * The reasons for adding the products like this are:
   3292      *  1. It avoids manual carry tracking. Just like how
   3293      *     (9 * 9) + 9 + 9 = 99, the same applies with this for UINT64_MAX.
   3294      *     This avoids a lot of complexity.
   3295      *
   3296      *  2. It hints for, and on Clang, compiles to, the powerful UMAAL
   3297      *     instruction available in ARM's Digital Signal Processing extension
   3298      *     in 32-bit ARMv6 and later, which is shown below:
   3299      *
   3300      *         void UMAAL(xxh_u32 *RdLo, xxh_u32 *RdHi, xxh_u32 Rn, xxh_u32 Rm)
   3301      *         {
   3302      *             xxh_u64 product = (xxh_u64)*RdLo * (xxh_u64)*RdHi + Rn + Rm;
   3303      *             *RdLo = (xxh_u32)(product & 0xFFFFFFFF);
   3304      *             *RdHi = (xxh_u32)(product >> 32);
   3305      *         }
   3306      *
   3307      *     This instruction was designed for efficient long multiplication, and
   3308      *     allows this to be calculated in only 4 instructions at speeds
   3309      *     comparable to some 64-bit ALUs.
   3310      *
   3311      *  3. It isn't terrible on other platforms. Usually this will be a couple
   3312      *     of 32-bit ADD/ADCs.
   3313      */
   3314 
   3315     /* First calculate all of the cross products. */
   3316     xxh_u64 const lo_lo = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs & 0xFFFFFFFF);
   3317     xxh_u64 const hi_lo = XXH_mult32to64(lhs >> 32,        rhs & 0xFFFFFFFF);
   3318     xxh_u64 const lo_hi = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs >> 32);
   3319     xxh_u64 const hi_hi = XXH_mult32to64(lhs >> 32,        rhs >> 32);
   3320 
   3321     /* Now add the products together. These will never overflow. */
   3322     xxh_u64 const cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi;
   3323     xxh_u64 const upper = (hi_lo >> 32) + (cross >> 32)        + hi_hi;
   3324     xxh_u64 const lower = (cross << 32) | (lo_lo & 0xFFFFFFFF);
   3325 
   3326     XXH128_hash_t r128;
   3327     r128.low64  = lower;
   3328     r128.high64 = upper;
   3329     return r128;
   3330 #endif
   3331 }
   3332 
   3333 /*!
   3334  * @brief Calculates a 64-bit to 128-bit multiply, then XOR folds it.
   3335  *
   3336  * The reason for the separate function is to prevent passing too many structs
   3337  * around by value. This will hopefully inline the multiply, but we don't force it.
   3338  *
   3339  * @param lhs, rhs The 64-bit integers to multiply
   3340  * @return The low 64 bits of the product XOR'd by the high 64 bits.
   3341  * @see XXH_mult64to128()
   3342  */
   3343 static xxh_u64
   3344 XXH3_mul128_fold64(xxh_u64 lhs, xxh_u64 rhs)
   3345 {
   3346     XXH128_hash_t product = XXH_mult64to128(lhs, rhs);
   3347     return product.low64 ^ product.high64;
   3348 }
   3349 
   3350 /*! Seems to produce slightly better code on GCC for some reason. */
   3351 XXH_FORCE_INLINE xxh_u64 XXH_xorshift64(xxh_u64 v64, int shift)
   3352 {
   3353     XXH_ASSERT(0 <= shift && shift < 64);
   3354     return v64 ^ (v64 >> shift);
   3355 }
   3356 
   3357 /*
   3358  * This is a fast avalanche stage,
   3359  * suitable when input bits are already partially mixed
   3360  */
   3361 static XXH64_hash_t XXH3_avalanche(xxh_u64 h64)
   3362 {
   3363     h64 = XXH_xorshift64(h64, 37);
   3364     h64 *= 0x165667919E3779F9ULL;
   3365     h64 = XXH_xorshift64(h64, 32);
   3366     return h64;
   3367 }
   3368 
   3369 /*
   3370  * This is a stronger avalanche,
   3371  * inspired by Pelle Evensen's rrmxmx
   3372  * preferable when input has not been previously mixed
   3373  */
   3374 static XXH64_hash_t XXH3_rrmxmx(xxh_u64 h64, xxh_u64 len)
   3375 {
   3376     /* this mix is inspired by Pelle Evensen's rrmxmx */
   3377     h64 ^= XXH_rotl64(h64, 49) ^ XXH_rotl64(h64, 24);
   3378     h64 *= 0x9FB21C651E98DF25ULL;
   3379     h64 ^= (h64 >> 35) + len ;
   3380     h64 *= 0x9FB21C651E98DF25ULL;
   3381     return XXH_xorshift64(h64, 28);
   3382 }
   3383 
   3384 
   3385 /* ==========================================
   3386  * Short keys
   3387  * ==========================================
   3388  * One of the shortcomings of XXH32 and XXH64 was that their performance was
   3389  * sub-optimal on short lengths. It used an iterative algorithm which strongly
   3390  * favored lengths that were a multiple of 4 or 8.
   3391  *
   3392  * Instead of iterating over individual inputs, we use a set of single shot
   3393  * functions which piece together a range of lengths and operate in constant time.
   3394  *
   3395  * Additionally, the number of multiplies has been significantly reduced. This
   3396  * reduces latency, especially when emulating 64-bit multiplies on 32-bit.
   3397  *
   3398  * Depending on the platform, this may or may not be faster than XXH32, but it
   3399  * is almost guaranteed to be faster than XXH64.
   3400  */
   3401 
   3402 /*
   3403  * At very short lengths, there isn't enough input to fully hide secrets, or use
   3404  * the entire secret.
   3405  *
   3406  * There is also only a limited amount of mixing we can do before significantly
   3407  * impacting performance.
   3408  *
   3409  * Therefore, we use different sections of the secret and always mix two secret
   3410  * samples with an XOR. This should have no effect on performance on the
   3411  * seedless or withSeed variants because everything _should_ be constant folded
   3412  * by modern compilers.
   3413  *
   3414  * The XOR mixing hides individual parts of the secret and increases entropy.
   3415  *
   3416  * This adds an extra layer of strength for custom secrets.
   3417  */
   3418 XXH_FORCE_INLINE XXH64_hash_t
   3419 XXH3_len_1to3_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   3420 {
   3421     XXH_ASSERT(input != NULL);
   3422     XXH_ASSERT(1 <= len && len <= 3);
   3423     XXH_ASSERT(secret != NULL);
   3424     /*
   3425      * len = 1: combined = { input[0], 0x01, input[0], input[0] }
   3426      * len = 2: combined = { input[1], 0x02, input[0], input[1] }
   3427      * len = 3: combined = { input[2], 0x03, input[0], input[1] }
   3428      */
   3429     {   xxh_u8  const c1 = input[0];
   3430         xxh_u8  const c2 = input[len >> 1];
   3431         xxh_u8  const c3 = input[len - 1];
   3432         xxh_u32 const combined = ((xxh_u32)c1 << 16) | ((xxh_u32)c2  << 24)
   3433                                | ((xxh_u32)c3 <<  0) | ((xxh_u32)len << 8);
   3434         xxh_u64 const bitflip = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
   3435         xxh_u64 const keyed = (xxh_u64)combined ^ bitflip;
   3436         return XXH64_avalanche(keyed);
   3437     }
   3438 }
   3439 
   3440 XXH_FORCE_INLINE XXH64_hash_t
   3441 XXH3_len_4to8_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   3442 {
   3443     XXH_ASSERT(input != NULL);
   3444     XXH_ASSERT(secret != NULL);
   3445     XXH_ASSERT(4 <= len && len < 8);
   3446     seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
   3447     {   xxh_u32 const input1 = XXH_readLE32(input);
   3448         xxh_u32 const input2 = XXH_readLE32(input + len - 4);
   3449         xxh_u64 const bitflip = (XXH_readLE64(secret+8) ^ XXH_readLE64(secret+16)) - seed;
   3450         xxh_u64 const input64 = input2 + (((xxh_u64)input1) << 32);
   3451         xxh_u64 const keyed = input64 ^ bitflip;
   3452         return XXH3_rrmxmx(keyed, len);
   3453     }
   3454 }
   3455 
   3456 XXH_FORCE_INLINE XXH64_hash_t
   3457 XXH3_len_9to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   3458 {
   3459     XXH_ASSERT(input != NULL);
   3460     XXH_ASSERT(secret != NULL);
   3461     XXH_ASSERT(8 <= len && len <= 16);
   3462     {   xxh_u64 const bitflip1 = (XXH_readLE64(secret+24) ^ XXH_readLE64(secret+32)) + seed;
   3463         xxh_u64 const bitflip2 = (XXH_readLE64(secret+40) ^ XXH_readLE64(secret+48)) - seed;
   3464         xxh_u64 const input_lo = XXH_readLE64(input)           ^ bitflip1;
   3465         xxh_u64 const input_hi = XXH_readLE64(input + len - 8) ^ bitflip2;
   3466         xxh_u64 const acc = len
   3467                           + XXH_swap64(input_lo) + input_hi
   3468                           + XXH3_mul128_fold64(input_lo, input_hi);
   3469         return XXH3_avalanche(acc);
   3470     }
   3471 }
   3472 
   3473 XXH_FORCE_INLINE XXH64_hash_t
   3474 XXH3_len_0to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   3475 {
   3476     XXH_ASSERT(len <= 16);
   3477     {   if (XXH_likely(len >  8)) return XXH3_len_9to16_64b(input, len, secret, seed);
   3478         if (XXH_likely(len >= 4)) return XXH3_len_4to8_64b(input, len, secret, seed);
   3479         if (len) return XXH3_len_1to3_64b(input, len, secret, seed);
   3480         return XXH64_avalanche(seed ^ (XXH_readLE64(secret+56) ^ XXH_readLE64(secret+64)));
   3481     }
   3482 }
   3483 
   3484 /*
   3485  * DISCLAIMER: There are known *seed-dependent* multicollisions here due to
   3486  * multiplication by zero, affecting hashes of lengths 17 to 240.
   3487  *
   3488  * However, they are very unlikely.
   3489  *
   3490  * Keep this in mind when using the unseeded XXH3_64bits() variant: As with all
   3491  * unseeded non-cryptographic hashes, it does not attempt to defend itself
   3492  * against specially crafted inputs, only random inputs.
   3493  *
   3494  * Compared to classic UMAC where a 1 in 2^31 chance of 4 consecutive bytes
   3495  * cancelling out the secret is taken an arbitrary number of times (addressed
   3496  * in XXH3_accumulate_512), this collision is very unlikely with random inputs
   3497  * and/or proper seeding:
   3498  *
   3499  * This only has a 1 in 2^63 chance of 8 consecutive bytes cancelling out, in a
   3500  * function that is only called up to 16 times per hash with up to 240 bytes of
   3501  * input.
   3502  *
   3503  * This is not too bad for a non-cryptographic hash function, especially with
   3504  * only 64 bit outputs.
   3505  *
   3506  * The 128-bit variant (which trades some speed for strength) is NOT affected
   3507  * by this, although it is always a good idea to use a proper seed if you care
   3508  * about strength.
   3509  */
   3510 XXH_FORCE_INLINE xxh_u64 XXH3_mix16B(const xxh_u8* XXH_RESTRICT input,
   3511                                      const xxh_u8* XXH_RESTRICT secret, xxh_u64 seed64)
   3512 {
   3513 #if defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
   3514   && defined(__i386__) && defined(__SSE2__)  /* x86 + SSE2 */ \
   3515   && !defined(XXH_ENABLE_AUTOVECTORIZE)      /* Define to disable like XXH32 hack */
   3516     /*
   3517      * UGLY HACK:
   3518      * GCC for x86 tends to autovectorize the 128-bit multiply, resulting in
   3519      * slower code.
   3520      *
   3521      * By forcing seed64 into a register, we disrupt the cost model and
   3522      * cause it to scalarize. See `XXH32_round()`
   3523      *
   3524      * FIXME: Clang's output is still _much_ faster -- On an AMD Ryzen 3600,
   3525      * XXH3_64bits @ len=240 runs at 4.6 GB/s with Clang 9, but 3.3 GB/s on
   3526      * GCC 9.2, despite both emitting scalar code.
   3527      *
   3528      * GCC generates much better scalar code than Clang for the rest of XXH3,
   3529      * which is why finding a more optimal codepath is an interest.
   3530      */
   3531     __asm__ ("" : "+r" (seed64));
   3532 #endif
   3533     {   xxh_u64 const input_lo = XXH_readLE64(input);
   3534         xxh_u64 const input_hi = XXH_readLE64(input+8);
   3535         return XXH3_mul128_fold64(
   3536             input_lo ^ (XXH_readLE64(secret)   + seed64),
   3537             input_hi ^ (XXH_readLE64(secret+8) - seed64)
   3538         );
   3539     }
   3540 }
   3541 
   3542 /* For mid range keys, XXH3 uses a Mum-hash variant. */
   3543 XXH_FORCE_INLINE XXH64_hash_t
   3544 XXH3_len_17to128_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
   3545                      const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
   3546                      XXH64_hash_t seed)
   3547 {
   3548     XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
   3549     XXH_ASSERT(16 < len && len <= 128);
   3550 
   3551     {   xxh_u64 acc = len * XXH_PRIME64_1;
   3552         if (len > 32) {
   3553             if (len > 64) {
   3554                 if (len > 96) {
   3555                     acc += XXH3_mix16B(input+48, secret+96, seed);
   3556                     acc += XXH3_mix16B(input+len-64, secret+112, seed);
   3557                 }
   3558                 acc += XXH3_mix16B(input+32, secret+64, seed);
   3559                 acc += XXH3_mix16B(input+len-48, secret+80, seed);
   3560             }
   3561             acc += XXH3_mix16B(input+16, secret+32, seed);
   3562             acc += XXH3_mix16B(input+len-32, secret+48, seed);
   3563         }
   3564         acc += XXH3_mix16B(input+0, secret+0, seed);
   3565         acc += XXH3_mix16B(input+len-16, secret+16, seed);
   3566 
   3567         return XXH3_avalanche(acc);
   3568     }
   3569 }
   3570 
   3571 #define XXH3_MIDSIZE_MAX 240
   3572 
   3573 XXH_NO_INLINE XXH64_hash_t
   3574 XXH3_len_129to240_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
   3575                       const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
   3576                       XXH64_hash_t seed)
   3577 {
   3578     XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
   3579     XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
   3580 
   3581     #define XXH3_MIDSIZE_STARTOFFSET 3
   3582     #define XXH3_MIDSIZE_LASTOFFSET  17
   3583 
   3584     {   xxh_u64 acc = len * XXH_PRIME64_1;
   3585         int const nbRounds = (int)len / 16;
   3586         int i;
   3587         for (i=0; i<8; i++) {
   3588             acc += XXH3_mix16B(input+(16*i), secret+(16*i), seed);
   3589         }
   3590         acc = XXH3_avalanche(acc);
   3591         XXH_ASSERT(nbRounds >= 8);
   3592 #if defined(__clang__)                                /* Clang */ \
   3593     && (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */ \
   3594     && !defined(XXH_ENABLE_AUTOVECTORIZE)             /* Define to disable */
   3595         /*
   3596          * UGLY HACK:
   3597          * Clang for ARMv7-A tries to vectorize this loop, similar to GCC x86.
   3598          * In everywhere else, it uses scalar code.
   3599          *
   3600          * For 64->128-bit multiplies, even if the NEON was 100% optimal, it
   3601          * would still be slower than UMAAL (see XXH_mult64to128).
   3602          *
   3603          * Unfortunately, Clang doesn't handle the long multiplies properly and
   3604          * converts them to the nonexistent "vmulq_u64" intrinsic, which is then
   3605          * scalarized into an ugly mess of VMOV.32 instructions.
   3606          *
   3607          * This mess is difficult to avoid without turning autovectorization
   3608          * off completely, but they are usually relatively minor and/or not
   3609          * worth it to fix.
   3610          *
   3611          * This loop is the easiest to fix, as unlike XXH32, this pragma
   3612          * _actually works_ because it is a loop vectorization instead of an
   3613          * SLP vectorization.
   3614          */
   3615         #pragma clang loop vectorize(disable)
   3616 #endif
   3617         for (i=8 ; i < nbRounds; i++) {
   3618             acc += XXH3_mix16B(input+(16*i), secret+(16*(i-8)) + XXH3_MIDSIZE_STARTOFFSET, seed);
   3619         }
   3620         /* last bytes */
   3621         acc += XXH3_mix16B(input + len - 16, secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET, seed);
   3622         return XXH3_avalanche(acc);
   3623     }
   3624 }
   3625 
   3626 
   3627 /* =======     Long Keys     ======= */
   3628 
   3629 #define XXH_STRIPE_LEN 64
   3630 #define XXH_SECRET_CONSUME_RATE 8   /* nb of secret bytes consumed at each accumulation */
   3631 #define XXH_ACC_NB (XXH_STRIPE_LEN / sizeof(xxh_u64))
   3632 
   3633 #ifdef XXH_OLD_NAMES
   3634 #  define STRIPE_LEN XXH_STRIPE_LEN
   3635 #  define ACC_NB XXH_ACC_NB
   3636 #endif
   3637 
   3638 XXH_FORCE_INLINE void XXH_writeLE64(void* dst, xxh_u64 v64)
   3639 {
   3640     if (!XXH_CPU_LITTLE_ENDIAN) v64 = XXH_swap64(v64);
   3641     memcpy(dst, &v64, sizeof(v64));
   3642 }
   3643 
   3644 /* Several intrinsic functions below are supposed to accept __int64 as argument,
   3645  * as documented in https://software.intel.com/sites/landingpage/IntrinsicsGuide/ .
   3646  * However, several environments do not define __int64 type,
   3647  * requiring a workaround.
   3648  */
   3649 #if !defined (__VMS) \
   3650   && (defined (__cplusplus) \
   3651   || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
   3652     typedef int64_t xxh_i64;
   3653 #else
   3654     /* the following type must have a width of 64-bit */
   3655     typedef long long xxh_i64;
   3656 #endif
   3657 
   3658 /*
   3659  * XXH3_accumulate_512 is the tightest loop for long inputs, and it is the most optimized.
   3660  *
   3661  * It is a hardened version of UMAC, based off of FARSH's implementation.
   3662  *
   3663  * This was chosen because it adapts quite well to 32-bit, 64-bit, and SIMD
   3664  * implementations, and it is ridiculously fast.
   3665  *
   3666  * We harden it by mixing the original input to the accumulators as well as the product.
   3667  *
   3668  * This means that in the (relatively likely) case of a multiply by zero, the
   3669  * original input is preserved.
   3670  *
   3671  * On 128-bit inputs, we swap 64-bit pairs when we add the input to improve
   3672  * cross-pollination, as otherwise the upper and lower halves would be
   3673  * essentially independent.
   3674  *
   3675  * This doesn't matter on 64-bit hashes since they all get merged together in
   3676  * the end, so we skip the extra step.
   3677  *
   3678  * Both XXH3_64bits and XXH3_128bits use this subroutine.
   3679  */
   3680 
   3681 #if (XXH_VECTOR == XXH_AVX512) \
   3682      || (defined(XXH_DISPATCH_AVX512) && XXH_DISPATCH_AVX512 != 0)
   3683 
   3684 #ifndef XXH_TARGET_AVX512
   3685 # define XXH_TARGET_AVX512  /* disable attribute target */
   3686 #endif
   3687 
   3688 XXH_FORCE_INLINE XXH_TARGET_AVX512 void
   3689 XXH3_accumulate_512_avx512(void* XXH_RESTRICT acc,
   3690                      const void* XXH_RESTRICT input,
   3691                      const void* XXH_RESTRICT secret)
   3692 {
   3693     XXH_ALIGN(64) __m512i* const xacc = (__m512i *) acc;
   3694     XXH_ASSERT((((size_t)acc) & 63) == 0);
   3695     XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));
   3696 
   3697     {
   3698         /* data_vec    = input[0]; */
   3699         __m512i const data_vec    = _mm512_loadu_si512   (input);
   3700         /* key_vec     = secret[0]; */
   3701         __m512i const key_vec     = _mm512_loadu_si512   (secret);
   3702         /* data_key    = data_vec ^ key_vec; */
   3703         __m512i const data_key    = _mm512_xor_si512     (data_vec, key_vec);
   3704         /* data_key_lo = data_key >> 32; */
   3705         __m512i const data_key_lo = _mm512_shuffle_epi32 (data_key, (_MM_PERM_ENUM)_MM_SHUFFLE(0, 3, 0, 1));
   3706         /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
   3707         __m512i const product     = _mm512_mul_epu32     (data_key, data_key_lo);
   3708         /* xacc[0] += swap(data_vec); */
   3709         __m512i const data_swap = _mm512_shuffle_epi32(data_vec, (_MM_PERM_ENUM)_MM_SHUFFLE(1, 0, 3, 2));
   3710         __m512i const sum       = _mm512_add_epi64(*xacc, data_swap);
   3711         /* xacc[0] += product; */
   3712         *xacc = _mm512_add_epi64(product, sum);
   3713     }
   3714 }
   3715 
   3716 /*
   3717  * XXH3_scrambleAcc: Scrambles the accumulators to improve mixing.
   3718  *
   3719  * Multiplication isn't perfect, as explained by Google in HighwayHash:
   3720  *
   3721  *  // Multiplication mixes/scrambles bytes 0-7 of the 64-bit result to
   3722  *  // varying degrees. In descending order of goodness, bytes
   3723  *  // 3 4 2 5 1 6 0 7 have quality 228 224 164 160 100 96 36 32.
   3724  *  // As expected, the upper and lower bytes are much worse.
   3725  *
   3726  * Source: https://github.com/google/highwayhash/blob/0aaf66b/highwayhash/hh_avx2.h#L291
   3727  *
   3728  * Since our algorithm uses a pseudorandom secret to add some variance into the
   3729  * mix, we don't need to (or want to) mix as often or as much as HighwayHash does.
   3730  *
   3731  * This isn't as tight as XXH3_accumulate, but still written in SIMD to avoid
   3732  * extraction.
   3733  *
   3734  * Both XXH3_64bits and XXH3_128bits use this subroutine.
   3735  */
   3736 
   3737 XXH_FORCE_INLINE XXH_TARGET_AVX512 void
   3738 XXH3_scrambleAcc_avx512(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
   3739 {
   3740     XXH_ASSERT((((size_t)acc) & 63) == 0);
   3741     XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));
   3742     {   XXH_ALIGN(64) __m512i* const xacc = (__m512i*) acc;
   3743         const __m512i prime32 = _mm512_set1_epi32((int)XXH_PRIME32_1);
   3744 
   3745         /* xacc[0] ^= (xacc[0] >> 47) */
   3746         __m512i const acc_vec     = *xacc;
   3747         __m512i const shifted     = _mm512_srli_epi64    (acc_vec, 47);
   3748         __m512i const data_vec    = _mm512_xor_si512     (acc_vec, shifted);
   3749         /* xacc[0] ^= secret; */
   3750         __m512i const key_vec     = _mm512_loadu_si512   (secret);
   3751         __m512i const data_key    = _mm512_xor_si512     (data_vec, key_vec);
   3752 
   3753         /* xacc[0] *= XXH_PRIME32_1; */
   3754         __m512i const data_key_hi = _mm512_shuffle_epi32 (data_key, (_MM_PERM_ENUM)_MM_SHUFFLE(0, 3, 0, 1));
   3755         __m512i const prod_lo     = _mm512_mul_epu32     (data_key, prime32);
   3756         __m512i const prod_hi     = _mm512_mul_epu32     (data_key_hi, prime32);
   3757         *xacc = _mm512_add_epi64(prod_lo, _mm512_slli_epi64(prod_hi, 32));
   3758     }
   3759 }
   3760 
   3761 XXH_FORCE_INLINE XXH_TARGET_AVX512 void
   3762 XXH3_initCustomSecret_avx512(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
   3763 {
   3764     XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 63) == 0);
   3765     XXH_STATIC_ASSERT(XXH_SEC_ALIGN == 64);
   3766     XXH_ASSERT(((size_t)customSecret & 63) == 0);
   3767     (void)(&XXH_writeLE64);
   3768     {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m512i);
   3769         __m512i const seed = _mm512_mask_set1_epi64(_mm512_set1_epi64((xxh_i64)seed64), 0xAA, -(xxh_i64)seed64);
   3770 
   3771         XXH_ALIGN(64) const __m512i* const src  = (const __m512i*) XXH3_kSecret;
   3772         XXH_ALIGN(64)       __m512i* const dest = (      __m512i*) customSecret;
   3773         int i;
   3774         for (i=0; i < nbRounds; ++i) {
   3775             /* GCC has a bug, _mm512_stream_load_si512 accepts 'void*', not 'void const*',
   3776              * this will warn "discards ‘const’ qualifier". */
   3777             union {
   3778                 XXH_ALIGN(64) const __m512i* cp;
   3779                 XXH_ALIGN(64) void* p;
   3780             } remote_const_void;
   3781             remote_const_void.cp = src + i;
   3782             dest[i] = _mm512_add_epi64(_mm512_stream_load_si512(remote_const_void.p), seed);
   3783     }   }
   3784 }
   3785 
   3786 #endif
   3787 
   3788 #if (XXH_VECTOR == XXH_AVX2) \
   3789     || (defined(XXH_DISPATCH_AVX2) && XXH_DISPATCH_AVX2 != 0)
   3790 
   3791 #ifndef XXH_TARGET_AVX2
   3792 # define XXH_TARGET_AVX2  /* disable attribute target */
   3793 #endif
   3794 
   3795 XXH_FORCE_INLINE XXH_TARGET_AVX2 void
   3796 XXH3_accumulate_512_avx2( void* XXH_RESTRICT acc,
   3797                     const void* XXH_RESTRICT input,
   3798                     const void* XXH_RESTRICT secret)
   3799 {
   3800     XXH_ASSERT((((size_t)acc) & 31) == 0);
   3801     {   XXH_ALIGN(32) __m256i* const xacc    =       (__m256i *) acc;
   3802         /* Unaligned. This is mainly for pointer arithmetic, and because
   3803          * _mm256_loadu_si256 requires  a const __m256i * pointer for some reason. */
   3804         const         __m256i* const xinput  = (const __m256i *) input;
   3805         /* Unaligned. This is mainly for pointer arithmetic, and because
   3806          * _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
   3807         const         __m256i* const xsecret = (const __m256i *) secret;
   3808 
   3809         size_t i;
   3810         for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
   3811             /* data_vec    = xinput[i]; */
   3812             __m256i const data_vec    = _mm256_loadu_si256    (xinput+i);
   3813             /* key_vec     = xsecret[i]; */
   3814             __m256i const key_vec     = _mm256_loadu_si256   (xsecret+i);
   3815             /* data_key    = data_vec ^ key_vec; */
   3816             __m256i const data_key    = _mm256_xor_si256     (data_vec, key_vec);
   3817             /* data_key_lo = data_key >> 32; */
   3818             __m256i const data_key_lo = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
   3819             /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
   3820             __m256i const product     = _mm256_mul_epu32     (data_key, data_key_lo);
   3821             /* xacc[i] += swap(data_vec); */
   3822             __m256i const data_swap = _mm256_shuffle_epi32(data_vec, _MM_SHUFFLE(1, 0, 3, 2));
   3823             __m256i const sum       = _mm256_add_epi64(xacc[i], data_swap);
   3824             /* xacc[i] += product; */
   3825             xacc[i] = _mm256_add_epi64(product, sum);
   3826     }   }
   3827 }
   3828 
   3829 XXH_FORCE_INLINE XXH_TARGET_AVX2 void
   3830 XXH3_scrambleAcc_avx2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
   3831 {
   3832     XXH_ASSERT((((size_t)acc) & 31) == 0);
   3833     {   XXH_ALIGN(32) __m256i* const xacc = (__m256i*) acc;
   3834         /* Unaligned. This is mainly for pointer arithmetic, and because
   3835          * _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
   3836         const         __m256i* const xsecret = (const __m256i *) secret;
   3837         const __m256i prime32 = _mm256_set1_epi32((int)XXH_PRIME32_1);
   3838 
   3839         size_t i;
   3840         for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
   3841             /* xacc[i] ^= (xacc[i] >> 47) */
   3842             __m256i const acc_vec     = xacc[i];
   3843             __m256i const shifted     = _mm256_srli_epi64    (acc_vec, 47);
   3844             __m256i const data_vec    = _mm256_xor_si256     (acc_vec, shifted);
   3845             /* xacc[i] ^= xsecret; */
   3846             __m256i const key_vec     = _mm256_loadu_si256   (xsecret+i);
   3847             __m256i const data_key    = _mm256_xor_si256     (data_vec, key_vec);
   3848 
   3849             /* xacc[i] *= XXH_PRIME32_1; */
   3850             __m256i const data_key_hi = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
   3851             __m256i const prod_lo     = _mm256_mul_epu32     (data_key, prime32);
   3852             __m256i const prod_hi     = _mm256_mul_epu32     (data_key_hi, prime32);
   3853             xacc[i] = _mm256_add_epi64(prod_lo, _mm256_slli_epi64(prod_hi, 32));
   3854         }
   3855     }
   3856 }
   3857 
   3858 XXH_FORCE_INLINE XXH_TARGET_AVX2 void XXH3_initCustomSecret_avx2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
   3859 {
   3860     XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 31) == 0);
   3861     XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE / sizeof(__m256i)) == 6);
   3862     XXH_STATIC_ASSERT(XXH_SEC_ALIGN <= 64);
   3863     (void)(&XXH_writeLE64);
   3864     XXH_PREFETCH(customSecret);
   3865     {   __m256i const seed = _mm256_set_epi64x(-(xxh_i64)seed64, (xxh_i64)seed64, -(xxh_i64)seed64, (xxh_i64)seed64);
   3866 
   3867         XXH_ALIGN(64) const __m256i* const src  = (const __m256i*) XXH3_kSecret;
   3868         XXH_ALIGN(64)       __m256i*       dest = (      __m256i*) customSecret;
   3869 
   3870 #       if defined(__GNUC__) || defined(__clang__)
   3871         /*
   3872          * On GCC & Clang, marking 'dest' as modified will cause the compiler:
   3873          *   - do not extract the secret from sse registers in the internal loop
   3874          *   - use less common registers, and avoid pushing these reg into stack
   3875          * The asm hack causes Clang to assume that XXH3_kSecretPtr aliases with
   3876          * customSecret, and on aarch64, this prevented LDP from merging two
   3877          * loads together for free. Putting the loads together before the stores
   3878          * properly generates LDP.
   3879          */
   3880         __asm__("" : "+r" (dest));
   3881 #       endif
   3882 
   3883         /* GCC -O2 need unroll loop manually */
   3884         dest[0] = _mm256_add_epi64(_mm256_stream_load_si256(src+0), seed);
   3885         dest[1] = _mm256_add_epi64(_mm256_stream_load_si256(src+1), seed);
   3886         dest[2] = _mm256_add_epi64(_mm256_stream_load_si256(src+2), seed);
   3887         dest[3] = _mm256_add_epi64(_mm256_stream_load_si256(src+3), seed);
   3888         dest[4] = _mm256_add_epi64(_mm256_stream_load_si256(src+4), seed);
   3889         dest[5] = _mm256_add_epi64(_mm256_stream_load_si256(src+5), seed);
   3890     }
   3891 }
   3892 
   3893 #endif
   3894 
   3895 /* x86dispatch always generates SSE2 */
   3896 #if (XXH_VECTOR == XXH_SSE2) || defined(XXH_X86DISPATCH)
   3897 
   3898 #ifndef XXH_TARGET_SSE2
   3899 # define XXH_TARGET_SSE2  /* disable attribute target */
   3900 #endif
   3901 
   3902 XXH_FORCE_INLINE XXH_TARGET_SSE2 void
   3903 XXH3_accumulate_512_sse2( void* XXH_RESTRICT acc,
   3904                     const void* XXH_RESTRICT input,
   3905                     const void* XXH_RESTRICT secret)
   3906 {
   3907     /* SSE2 is just a half-scale version of the AVX2 version. */
   3908     XXH_ASSERT((((size_t)acc) & 15) == 0);
   3909     {   XXH_ALIGN(16) __m128i* const xacc    =       (__m128i *) acc;
   3910         /* Unaligned. This is mainly for pointer arithmetic, and because
   3911          * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
   3912         const         __m128i* const xinput  = (const __m128i *) input;
   3913         /* Unaligned. This is mainly for pointer arithmetic, and because
   3914          * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
   3915         const         __m128i* const xsecret = (const __m128i *) secret;
   3916 
   3917         size_t i;
   3918         for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
   3919             /* data_vec    = xinput[i]; */
   3920             __m128i const data_vec    = _mm_loadu_si128   (xinput+i);
   3921             /* key_vec     = xsecret[i]; */
   3922             __m128i const key_vec     = _mm_loadu_si128   (xsecret+i);
   3923             /* data_key    = data_vec ^ key_vec; */
   3924             __m128i const data_key    = _mm_xor_si128     (data_vec, key_vec);
   3925             /* data_key_lo = data_key >> 32; */
   3926             __m128i const data_key_lo = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
   3927             /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
   3928             __m128i const product     = _mm_mul_epu32     (data_key, data_key_lo);
   3929             /* xacc[i] += swap(data_vec); */
   3930             __m128i const data_swap = _mm_shuffle_epi32(data_vec, _MM_SHUFFLE(1,0,3,2));
   3931             __m128i const sum       = _mm_add_epi64(xacc[i], data_swap);
   3932             /* xacc[i] += product; */
   3933             xacc[i] = _mm_add_epi64(product, sum);
   3934     }   }
   3935 }
   3936 
   3937 XXH_FORCE_INLINE XXH_TARGET_SSE2 void
   3938 XXH3_scrambleAcc_sse2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
   3939 {
   3940     XXH_ASSERT((((size_t)acc) & 15) == 0);
   3941     {   XXH_ALIGN(16) __m128i* const xacc = (__m128i*) acc;
   3942         /* Unaligned. This is mainly for pointer arithmetic, and because
   3943          * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
   3944         const         __m128i* const xsecret = (const __m128i *) secret;
   3945         const __m128i prime32 = _mm_set1_epi32((int)XXH_PRIME32_1);
   3946 
   3947         size_t i;
   3948         for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
   3949             /* xacc[i] ^= (xacc[i] >> 47) */
   3950             __m128i const acc_vec     = xacc[i];
   3951             __m128i const shifted     = _mm_srli_epi64    (acc_vec, 47);
   3952             __m128i const data_vec    = _mm_xor_si128     (acc_vec, shifted);
   3953             /* xacc[i] ^= xsecret[i]; */
   3954             __m128i const key_vec     = _mm_loadu_si128   (xsecret+i);
   3955             __m128i const data_key    = _mm_xor_si128     (data_vec, key_vec);
   3956 
   3957             /* xacc[i] *= XXH_PRIME32_1; */
   3958             __m128i const data_key_hi = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
   3959             __m128i const prod_lo     = _mm_mul_epu32     (data_key, prime32);
   3960             __m128i const prod_hi     = _mm_mul_epu32     (data_key_hi, prime32);
   3961             xacc[i] = _mm_add_epi64(prod_lo, _mm_slli_epi64(prod_hi, 32));
   3962         }
   3963     }
   3964 }
   3965 
   3966 XXH_FORCE_INLINE XXH_TARGET_SSE2 void XXH3_initCustomSecret_sse2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
   3967 {
   3968     XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
   3969     (void)(&XXH_writeLE64);
   3970     {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m128i);
   3971 
   3972 #       if defined(_MSC_VER) && defined(_M_IX86) && _MSC_VER < 1900
   3973         // MSVC 32bit mode does not support _mm_set_epi64x before 2015
   3974         XXH_ALIGN(16) const xxh_i64 seed64x2[2] = { (xxh_i64)seed64, -(xxh_i64)seed64 };
   3975         __m128i const seed = _mm_load_si128((__m128i const*)seed64x2);
   3976 #       else
   3977         __m128i const seed = _mm_set_epi64x(-(xxh_i64)seed64, (xxh_i64)seed64);
   3978 #       endif
   3979         int i;
   3980 
   3981         XXH_ALIGN(64)        const float* const src  = (float const*) XXH3_kSecret;
   3982         XXH_ALIGN(XXH_SEC_ALIGN) __m128i*       dest = (__m128i*) customSecret;
   3983 #       if defined(__GNUC__) || defined(__clang__)
   3984         /*
   3985          * On GCC & Clang, marking 'dest' as modified will cause the compiler:
   3986          *   - do not extract the secret from sse registers in the internal loop
   3987          *   - use less common registers, and avoid pushing these reg into stack
   3988          */
   3989         __asm__("" : "+r" (dest));
   3990 #       endif
   3991 
   3992         for (i=0; i < nbRounds; ++i) {
   3993             dest[i] = _mm_add_epi64(_mm_castps_si128(_mm_load_ps(src+i*4)), seed);
   3994     }   }
   3995 }
   3996 
   3997 #endif
   3998 
   3999 #if (XXH_VECTOR == XXH_NEON)
   4000 
   4001 XXH_FORCE_INLINE void
   4002 XXH3_accumulate_512_neon( void* XXH_RESTRICT acc,
   4003                     const void* XXH_RESTRICT input,
   4004                     const void* XXH_RESTRICT secret)
   4005 {
   4006     XXH_ASSERT((((size_t)acc) & 15) == 0);
   4007     {
   4008         XXH_ALIGN(16) uint64x2_t* const xacc = (uint64x2_t *) acc;
   4009         /* We don't use a uint32x4_t pointer because it causes bus errors on ARMv7. */
   4010         uint8_t const* const xinput = (const uint8_t *) input;
   4011         uint8_t const* const xsecret  = (const uint8_t *) secret;
   4012 
   4013         size_t i;
   4014         for (i=0; i < XXH_STRIPE_LEN / sizeof(uint64x2_t); i++) {
   4015             /* data_vec = xinput[i]; */
   4016             uint8x16_t data_vec    = vld1q_u8(xinput  + (i * 16));
   4017             /* key_vec  = xsecret[i];  */
   4018             uint8x16_t key_vec     = vld1q_u8(xsecret + (i * 16));
   4019             uint64x2_t data_key;
   4020             uint32x2_t data_key_lo, data_key_hi;
   4021             /* xacc[i] += swap(data_vec); */
   4022             uint64x2_t const data64  = vreinterpretq_u64_u8(data_vec);
   4023             uint64x2_t const swapped = vextq_u64(data64, data64, 1);
   4024             xacc[i] = vaddq_u64 (xacc[i], swapped);
   4025             /* data_key = data_vec ^ key_vec; */
   4026             data_key = vreinterpretq_u64_u8(veorq_u8(data_vec, key_vec));
   4027             /* data_key_lo = (uint32x2_t) (data_key & 0xFFFFFFFF);
   4028              * data_key_hi = (uint32x2_t) (data_key >> 32);
   4029              * data_key = UNDEFINED; */
   4030             XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
   4031             /* xacc[i] += (uint64x2_t) data_key_lo * (uint64x2_t) data_key_hi; */
   4032             xacc[i] = vmlal_u32 (xacc[i], data_key_lo, data_key_hi);
   4033 
   4034         }
   4035     }
   4036 }
   4037 
   4038 XXH_FORCE_INLINE void
   4039 XXH3_scrambleAcc_neon(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
   4040 {
   4041     XXH_ASSERT((((size_t)acc) & 15) == 0);
   4042 
   4043     {   uint64x2_t* xacc       = (uint64x2_t*) acc;
   4044         uint8_t const* xsecret = (uint8_t const*) secret;
   4045         uint32x2_t prime       = vdup_n_u32 (XXH_PRIME32_1);
   4046 
   4047         size_t i;
   4048         for (i=0; i < XXH_STRIPE_LEN/sizeof(uint64x2_t); i++) {
   4049             /* xacc[i] ^= (xacc[i] >> 47); */
   4050             uint64x2_t acc_vec  = xacc[i];
   4051             uint64x2_t shifted  = vshrq_n_u64 (acc_vec, 47);
   4052             uint64x2_t data_vec = veorq_u64   (acc_vec, shifted);
   4053 
   4054             /* xacc[i] ^= xsecret[i]; */
   4055             uint8x16_t key_vec  = vld1q_u8(xsecret + (i * 16));
   4056             uint64x2_t data_key = veorq_u64(data_vec, vreinterpretq_u64_u8(key_vec));
   4057 
   4058             /* xacc[i] *= XXH_PRIME32_1 */
   4059             uint32x2_t data_key_lo, data_key_hi;
   4060             /* data_key_lo = (uint32x2_t) (xacc[i] & 0xFFFFFFFF);
   4061              * data_key_hi = (uint32x2_t) (xacc[i] >> 32);
   4062              * xacc[i] = UNDEFINED; */
   4063             XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
   4064             {   /*
   4065                  * prod_hi = (data_key >> 32) * XXH_PRIME32_1;
   4066                  *
   4067                  * Avoid vmul_u32 + vshll_n_u32 since Clang 6 and 7 will
   4068                  * incorrectly "optimize" this:
   4069                  *   tmp     = vmul_u32(vmovn_u64(a), vmovn_u64(b));
   4070                  *   shifted = vshll_n_u32(tmp, 32);
   4071                  * to this:
   4072                  *   tmp     = "vmulq_u64"(a, b); // no such thing!
   4073                  *   shifted = vshlq_n_u64(tmp, 32);
   4074                  *
   4075                  * However, unlike SSE, Clang lacks a 64-bit multiply routine
   4076                  * for NEON, and it scalarizes two 64-bit multiplies instead.
   4077                  *
   4078                  * vmull_u32 has the same timing as vmul_u32, and it avoids
   4079                  * this bug completely.
   4080                  * See https://bugs.llvm.org/show_bug.cgi?id=39967
   4081                  */
   4082                 uint64x2_t prod_hi = vmull_u32 (data_key_hi, prime);
   4083                 /* xacc[i] = prod_hi << 32; */
   4084                 xacc[i] = vshlq_n_u64(prod_hi, 32);
   4085                 /* xacc[i] += (prod_hi & 0xFFFFFFFF) * XXH_PRIME32_1; */
   4086                 xacc[i] = vmlal_u32(xacc[i], data_key_lo, prime);
   4087             }
   4088     }   }
   4089 }
   4090 
   4091 #endif
   4092 
   4093 #if (XXH_VECTOR == XXH_VSX)
   4094 
   4095 XXH_FORCE_INLINE void
   4096 XXH3_accumulate_512_vsx(  void* XXH_RESTRICT acc,
   4097                     const void* XXH_RESTRICT input,
   4098                     const void* XXH_RESTRICT secret)
   4099 {
   4100           xxh_u64x2* const xacc     =       (xxh_u64x2*) acc;    /* presumed aligned */
   4101     xxh_u64x2 const* const xinput   = (xxh_u64x2 const*) input;   /* no alignment restriction */
   4102     xxh_u64x2 const* const xsecret  = (xxh_u64x2 const*) secret;    /* no alignment restriction */
   4103     xxh_u64x2 const v32 = { 32, 32 };
   4104     size_t i;
   4105     for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
   4106         /* data_vec = xinput[i]; */
   4107         xxh_u64x2 const data_vec = XXH_vec_loadu(xinput + i);
   4108         /* key_vec = xsecret[i]; */
   4109         xxh_u64x2 const key_vec  = XXH_vec_loadu(xsecret + i);
   4110         xxh_u64x2 const data_key = data_vec ^ key_vec;
   4111         /* shuffled = (data_key << 32) | (data_key >> 32); */
   4112         xxh_u32x4 const shuffled = (xxh_u32x4)vec_rl(data_key, v32);
   4113         /* product = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)shuffled & 0xFFFFFFFF); */
   4114         xxh_u64x2 const product  = XXH_vec_mulo((xxh_u32x4)data_key, shuffled);
   4115         xacc[i] += product;
   4116 
   4117         /* swap high and low halves */
   4118 #ifdef __s390x__
   4119         xacc[i] += vec_permi(data_vec, data_vec, 2);
   4120 #else
   4121         xacc[i] += vec_xxpermdi(data_vec, data_vec, 2);
   4122 #endif
   4123     }
   4124 }
   4125 
   4126 XXH_FORCE_INLINE void
   4127 XXH3_scrambleAcc_vsx(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
   4128 {
   4129     XXH_ASSERT((((size_t)acc) & 15) == 0);
   4130 
   4131     {         xxh_u64x2* const xacc    =       (xxh_u64x2*) acc;
   4132         const xxh_u64x2* const xsecret = (const xxh_u64x2*) secret;
   4133         /* constants */
   4134         xxh_u64x2 const v32  = { 32, 32 };
   4135         xxh_u64x2 const v47 = { 47, 47 };
   4136         xxh_u32x4 const prime = { XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1 };
   4137         size_t i;
   4138         for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
   4139             /* xacc[i] ^= (xacc[i] >> 47); */
   4140             xxh_u64x2 const acc_vec  = xacc[i];
   4141             xxh_u64x2 const data_vec = acc_vec ^ (acc_vec >> v47);
   4142 
   4143             /* xacc[i] ^= xsecret[i]; */
   4144             xxh_u64x2 const key_vec  = XXH_vec_loadu(xsecret + i);
   4145             xxh_u64x2 const data_key = data_vec ^ key_vec;
   4146 
   4147             /* xacc[i] *= XXH_PRIME32_1 */
   4148             /* prod_lo = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)prime & 0xFFFFFFFF);  */
   4149             xxh_u64x2 const prod_even  = XXH_vec_mule((xxh_u32x4)data_key, prime);
   4150             /* prod_hi = ((xxh_u64x2)data_key >> 32) * ((xxh_u64x2)prime >> 32);  */
   4151             xxh_u64x2 const prod_odd  = XXH_vec_mulo((xxh_u32x4)data_key, prime);
   4152             xacc[i] = prod_odd + (prod_even << v32);
   4153     }   }
   4154 }
   4155 
   4156 #endif
   4157 
   4158 /* scalar variants - universal */
   4159 
   4160 XXH_FORCE_INLINE void
   4161 XXH3_accumulate_512_scalar(void* XXH_RESTRICT acc,
   4162                      const void* XXH_RESTRICT input,
   4163                      const void* XXH_RESTRICT secret)
   4164 {
   4165     XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64* const xacc = (xxh_u64*) acc; /* presumed aligned */
   4166     const xxh_u8* const xinput  = (const xxh_u8*) input;  /* no alignment restriction */
   4167     const xxh_u8* const xsecret = (const xxh_u8*) secret;   /* no alignment restriction */
   4168     size_t i;
   4169     XXH_ASSERT(((size_t)acc & (XXH_ACC_ALIGN-1)) == 0);
   4170     for (i=0; i < XXH_ACC_NB; i++) {
   4171         xxh_u64 const data_val = XXH_readLE64(xinput + 8*i);
   4172         xxh_u64 const data_key = data_val ^ XXH_readLE64(xsecret + i*8);
   4173         xacc[i ^ 1] += data_val; /* swap adjacent lanes */
   4174         xacc[i] += XXH_mult32to64(data_key & 0xFFFFFFFF, data_key >> 32);
   4175     }
   4176 }
   4177 
   4178 XXH_FORCE_INLINE void
   4179 XXH3_scrambleAcc_scalar(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
   4180 {
   4181     XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64* const xacc = (xxh_u64*) acc;   /* presumed aligned */
   4182     const xxh_u8* const xsecret = (const xxh_u8*) secret;   /* no alignment restriction */
   4183     size_t i;
   4184     XXH_ASSERT((((size_t)acc) & (XXH_ACC_ALIGN-1)) == 0);
   4185     for (i=0; i < XXH_ACC_NB; i++) {
   4186         xxh_u64 const key64 = XXH_readLE64(xsecret + 8*i);
   4187         xxh_u64 acc64 = xacc[i];
   4188         acc64 = XXH_xorshift64(acc64, 47);
   4189         acc64 ^= key64;
   4190         acc64 *= XXH_PRIME32_1;
   4191         xacc[i] = acc64;
   4192     }
   4193 }
   4194 
   4195 XXH_FORCE_INLINE void
   4196 XXH3_initCustomSecret_scalar(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
   4197 {
   4198     /*
   4199      * We need a separate pointer for the hack below,
   4200      * which requires a non-const pointer.
   4201      * Any decent compiler will optimize this out otherwise.
   4202      */
   4203     const xxh_u8* kSecretPtr = XXH3_kSecret;
   4204     XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
   4205 
   4206 #if defined(__clang__) && defined(__aarch64__)
   4207     /*
   4208      * UGLY HACK:
   4209      * Clang generates a bunch of MOV/MOVK pairs for aarch64, and they are
   4210      * placed sequentially, in order, at the top of the unrolled loop.
   4211      *
   4212      * While MOVK is great for generating constants (2 cycles for a 64-bit
   4213      * constant compared to 4 cycles for LDR), long MOVK chains stall the
   4214      * integer pipelines:
   4215      *   I   L   S
   4216      * MOVK
   4217      * MOVK
   4218      * MOVK
   4219      * MOVK
   4220      * ADD
   4221      * SUB      STR
   4222      *          STR
   4223      * By forcing loads from memory (as the asm line causes Clang to assume
   4224      * that XXH3_kSecretPtr has been changed), the pipelines are used more
   4225      * efficiently:
   4226      *   I   L   S
   4227      *      LDR
   4228      *  ADD LDR
   4229      *  SUB     STR
   4230      *          STR
   4231      * XXH3_64bits_withSeed, len == 256, Snapdragon 835
   4232      *   without hack: 2654.4 MB/s
   4233      *   with hack:    3202.9 MB/s
   4234      */
   4235     __asm__("" : "+r" (kSecretPtr));
   4236 #endif
   4237     /*
   4238      * Note: in debug mode, this overrides the asm optimization
   4239      * and Clang will emit MOVK chains again.
   4240      */
   4241     XXH_ASSERT(kSecretPtr == XXH3_kSecret);
   4242 
   4243     {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / 16;
   4244         int i;
   4245         for (i=0; i < nbRounds; i++) {
   4246             /*
   4247              * The asm hack causes Clang to assume that kSecretPtr aliases with
   4248              * customSecret, and on aarch64, this prevented LDP from merging two
   4249              * loads together for free. Putting the loads together before the stores
   4250              * properly generates LDP.
   4251              */
   4252             xxh_u64 lo = XXH_readLE64(kSecretPtr + 16*i)     + seed64;
   4253             xxh_u64 hi = XXH_readLE64(kSecretPtr + 16*i + 8) - seed64;
   4254             XXH_writeLE64((xxh_u8*)customSecret + 16*i,     lo);
   4255             XXH_writeLE64((xxh_u8*)customSecret + 16*i + 8, hi);
   4256     }   }
   4257 }
   4258 
   4259 
   4260 typedef void (*XXH3_f_accumulate_512)(void* XXH_RESTRICT, const void*, const void*);
   4261 typedef void (*XXH3_f_scrambleAcc)(void* XXH_RESTRICT, const void*);
   4262 typedef void (*XXH3_f_initCustomSecret)(void* XXH_RESTRICT, xxh_u64);
   4263 
   4264 
   4265 #if (XXH_VECTOR == XXH_AVX512)
   4266 
   4267 #define XXH3_accumulate_512 XXH3_accumulate_512_avx512
   4268 #define XXH3_scrambleAcc    XXH3_scrambleAcc_avx512
   4269 #define XXH3_initCustomSecret XXH3_initCustomSecret_avx512
   4270 
   4271 #elif (XXH_VECTOR == XXH_AVX2)
   4272 
   4273 #define XXH3_accumulate_512 XXH3_accumulate_512_avx2
   4274 #define XXH3_scrambleAcc    XXH3_scrambleAcc_avx2
   4275 #define XXH3_initCustomSecret XXH3_initCustomSecret_avx2
   4276 
   4277 #elif (XXH_VECTOR == XXH_SSE2)
   4278 
   4279 #define XXH3_accumulate_512 XXH3_accumulate_512_sse2
   4280 #define XXH3_scrambleAcc    XXH3_scrambleAcc_sse2
   4281 #define XXH3_initCustomSecret XXH3_initCustomSecret_sse2
   4282 
   4283 #elif (XXH_VECTOR == XXH_NEON)
   4284 
   4285 #define XXH3_accumulate_512 XXH3_accumulate_512_neon
   4286 #define XXH3_scrambleAcc    XXH3_scrambleAcc_neon
   4287 #define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
   4288 
   4289 #elif (XXH_VECTOR == XXH_VSX)
   4290 
   4291 #define XXH3_accumulate_512 XXH3_accumulate_512_vsx
   4292 #define XXH3_scrambleAcc    XXH3_scrambleAcc_vsx
   4293 #define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
   4294 
   4295 #else /* scalar */
   4296 
   4297 #define XXH3_accumulate_512 XXH3_accumulate_512_scalar
   4298 #define XXH3_scrambleAcc    XXH3_scrambleAcc_scalar
   4299 #define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
   4300 
   4301 #endif
   4302 
   4303 
   4304 
   4305 #ifndef XXH_PREFETCH_DIST
   4306 #  ifdef __clang__
   4307 #    define XXH_PREFETCH_DIST 320
   4308 #  else
   4309 #    if (XXH_VECTOR == XXH_AVX512)
   4310 #      define XXH_PREFETCH_DIST 512
   4311 #    else
   4312 #      define XXH_PREFETCH_DIST 384
   4313 #    endif
   4314 #  endif  /* __clang__ */
   4315 #endif  /* XXH_PREFETCH_DIST */
   4316 
   4317 /*
   4318  * XXH3_accumulate()
   4319  * Loops over XXH3_accumulate_512().
   4320  * Assumption: nbStripes will not overflow the secret size
   4321  */
   4322 XXH_FORCE_INLINE void
   4323 XXH3_accumulate(     xxh_u64* XXH_RESTRICT acc,
   4324                 const xxh_u8* XXH_RESTRICT input,
   4325                 const xxh_u8* XXH_RESTRICT secret,
   4326                       size_t nbStripes,
   4327                       XXH3_f_accumulate_512 f_acc512)
   4328 {
   4329     size_t n;
   4330     for (n = 0; n < nbStripes; n++ ) {
   4331         const xxh_u8* const in = input + n*XXH_STRIPE_LEN;
   4332         XXH_PREFETCH(in + XXH_PREFETCH_DIST);
   4333         f_acc512(acc,
   4334                  in,
   4335                  secret + n*XXH_SECRET_CONSUME_RATE);
   4336     }
   4337 }
   4338 
   4339 XXH_FORCE_INLINE void
   4340 XXH3_hashLong_internal_loop(xxh_u64* XXH_RESTRICT acc,
   4341                       const xxh_u8* XXH_RESTRICT input, size_t len,
   4342                       const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
   4343                             XXH3_f_accumulate_512 f_acc512,
   4344                             XXH3_f_scrambleAcc f_scramble)
   4345 {
   4346     size_t const nbStripesPerBlock = (secretSize - XXH_STRIPE_LEN) / XXH_SECRET_CONSUME_RATE;
   4347     size_t const block_len = XXH_STRIPE_LEN * nbStripesPerBlock;
   4348     size_t const nb_blocks = (len - 1) / block_len;
   4349 
   4350     size_t n;
   4351 
   4352     XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
   4353 
   4354     for (n = 0; n < nb_blocks; n++) {
   4355         XXH3_accumulate(acc, input + n*block_len, secret, nbStripesPerBlock, f_acc512);
   4356         f_scramble(acc, secret + secretSize - XXH_STRIPE_LEN);
   4357     }
   4358 
   4359     /* last partial block */
   4360     XXH_ASSERT(len > XXH_STRIPE_LEN);
   4361     {   size_t const nbStripes = ((len - 1) - (block_len * nb_blocks)) / XXH_STRIPE_LEN;
   4362         XXH_ASSERT(nbStripes <= (secretSize / XXH_SECRET_CONSUME_RATE));
   4363         XXH3_accumulate(acc, input + nb_blocks*block_len, secret, nbStripes, f_acc512);
   4364 
   4365         /* last stripe */
   4366         {   const xxh_u8* const p = input + len - XXH_STRIPE_LEN;
   4367 #define XXH_SECRET_LASTACC_START 7  /* not aligned on 8, last secret is different from acc & scrambler */
   4368             f_acc512(acc, p, secret + secretSize - XXH_STRIPE_LEN - XXH_SECRET_LASTACC_START);
   4369     }   }
   4370 }
   4371 
   4372 XXH_FORCE_INLINE xxh_u64
   4373 XXH3_mix2Accs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret)
   4374 {
   4375     return XXH3_mul128_fold64(
   4376                acc[0] ^ XXH_readLE64(secret),
   4377                acc[1] ^ XXH_readLE64(secret+8) );
   4378 }
   4379 
   4380 static XXH64_hash_t
   4381 XXH3_mergeAccs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret, xxh_u64 start)
   4382 {
   4383     xxh_u64 result64 = start;
   4384     size_t i = 0;
   4385 
   4386     for (i = 0; i < 4; i++) {
   4387         result64 += XXH3_mix2Accs(acc+2*i, secret + 16*i);
   4388 #if defined(__clang__)                                /* Clang */ \
   4389     && (defined(__arm__) || defined(__thumb__))       /* ARMv7 */ \
   4390     && (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */  \
   4391     && !defined(XXH_ENABLE_AUTOVECTORIZE)             /* Define to disable */
   4392         /*
   4393          * UGLY HACK:
   4394          * Prevent autovectorization on Clang ARMv7-a. Exact same problem as
   4395          * the one in XXH3_len_129to240_64b. Speeds up shorter keys > 240b.
   4396          * XXH3_64bits, len == 256, Snapdragon 835:
   4397          *   without hack: 2063.7 MB/s
   4398          *   with hack:    2560.7 MB/s
   4399          */
   4400         __asm__("" : "+r" (result64));
   4401 #endif
   4402     }
   4403 
   4404     return XXH3_avalanche(result64);
   4405 }
   4406 
   4407 #define XXH3_INIT_ACC { XXH_PRIME32_3, XXH_PRIME64_1, XXH_PRIME64_2, XXH_PRIME64_3, \
   4408                         XXH_PRIME64_4, XXH_PRIME32_2, XXH_PRIME64_5, XXH_PRIME32_1 }
   4409 
   4410 XXH_FORCE_INLINE XXH64_hash_t
   4411 XXH3_hashLong_64b_internal(const void* XXH_RESTRICT input, size_t len,
   4412                            const void* XXH_RESTRICT secret, size_t secretSize,
   4413                            XXH3_f_accumulate_512 f_acc512,
   4414                            XXH3_f_scrambleAcc f_scramble)
   4415 {
   4416     XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;
   4417 
   4418     XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, f_acc512, f_scramble);
   4419 
   4420     /* converge into final hash */
   4421     XXH_STATIC_ASSERT(sizeof(acc) == 64);
   4422     /* do not align on 8, so that the secret is different from the accumulator */
   4423 #define XXH_SECRET_MERGEACCS_START 11
   4424     XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
   4425     return XXH3_mergeAccs(acc, (const xxh_u8*)secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)len * XXH_PRIME64_1);
   4426 }
   4427 
   4428 /*
   4429  * It's important for performance that XXH3_hashLong is not inlined.
   4430  */
   4431 XXH_NO_INLINE XXH64_hash_t
   4432 XXH3_hashLong_64b_withSecret(const void* XXH_RESTRICT input, size_t len,
   4433                              XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
   4434 {
   4435     (void)seed64;
   4436     return XXH3_hashLong_64b_internal(input, len, secret, secretLen, XXH3_accumulate_512, XXH3_scrambleAcc);
   4437 }
   4438 
   4439 /*
   4440  * It's important for performance that XXH3_hashLong is not inlined.
   4441  * Since the function is not inlined, the compiler may not be able to understand that,
   4442  * in some scenarios, its `secret` argument is actually a compile time constant.
   4443  * This variant enforces that the compiler can detect that,
   4444  * and uses this opportunity to streamline the generated code for better performance.
   4445  */
   4446 XXH_NO_INLINE XXH64_hash_t
   4447 XXH3_hashLong_64b_default(const void* XXH_RESTRICT input, size_t len,
   4448                           XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
   4449 {
   4450     (void)seed64; (void)secret; (void)secretLen;
   4451     return XXH3_hashLong_64b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_accumulate_512, XXH3_scrambleAcc);
   4452 }
   4453 
   4454 /*
   4455  * XXH3_hashLong_64b_withSeed():
   4456  * Generate a custom key based on alteration of default XXH3_kSecret with the seed,
   4457  * and then use this key for long mode hashing.
   4458  *
   4459  * This operation is decently fast but nonetheless costs a little bit of time.
   4460  * Try to avoid it whenever possible (typically when seed==0).
   4461  *
   4462  * It's important for performance that XXH3_hashLong is not inlined. Not sure
   4463  * why (uop cache maybe?), but the difference is large and easily measurable.
   4464  */
   4465 XXH_FORCE_INLINE XXH64_hash_t
   4466 XXH3_hashLong_64b_withSeed_internal(const void* input, size_t len,
   4467                                     XXH64_hash_t seed,
   4468                                     XXH3_f_accumulate_512 f_acc512,
   4469                                     XXH3_f_scrambleAcc f_scramble,
   4470                                     XXH3_f_initCustomSecret f_initSec)
   4471 {
   4472     if (seed == 0)
   4473         return XXH3_hashLong_64b_internal(input, len,
   4474                                           XXH3_kSecret, sizeof(XXH3_kSecret),
   4475                                           f_acc512, f_scramble);
   4476     {   XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
   4477         f_initSec(secret, seed);
   4478         return XXH3_hashLong_64b_internal(input, len, secret, sizeof(secret),
   4479                                           f_acc512, f_scramble);
   4480     }
   4481 }
   4482 
   4483 /*
   4484  * It's important for performance that XXH3_hashLong is not inlined.
   4485  */
   4486 XXH_NO_INLINE XXH64_hash_t
   4487 XXH3_hashLong_64b_withSeed(const void* input, size_t len,
   4488                            XXH64_hash_t seed, const xxh_u8* secret, size_t secretLen)
   4489 {
   4490     (void)secret; (void)secretLen;
   4491     return XXH3_hashLong_64b_withSeed_internal(input, len, seed,
   4492                 XXH3_accumulate_512, XXH3_scrambleAcc, XXH3_initCustomSecret);
   4493 }
   4494 
   4495 
   4496 typedef XXH64_hash_t (*XXH3_hashLong64_f)(const void* XXH_RESTRICT, size_t,
   4497                                           XXH64_hash_t, const xxh_u8* XXH_RESTRICT, size_t);
   4498 
   4499 XXH_FORCE_INLINE XXH64_hash_t
   4500 XXH3_64bits_internal(const void* XXH_RESTRICT input, size_t len,
   4501                      XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
   4502                      XXH3_hashLong64_f f_hashLong)
   4503 {
   4504     XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
   4505     /*
   4506      * If an action is to be taken if `secretLen` condition is not respected,
   4507      * it should be done here.
   4508      * For now, it's a contract pre-condition.
   4509      * Adding a check and a branch here would cost performance at every hash.
   4510      * Also, note that function signature doesn't offer room to return an error.
   4511      */
   4512     if (len <= 16)
   4513         return XXH3_len_0to16_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
   4514     if (len <= 128)
   4515         return XXH3_len_17to128_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
   4516     if (len <= XXH3_MIDSIZE_MAX)
   4517         return XXH3_len_129to240_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
   4518     return f_hashLong(input, len, seed64, (const xxh_u8*)secret, secretLen);
   4519 }
   4520 
   4521 
   4522 /* ===   Public entry point   === */
   4523 
   4524 /*! @ingroup xxh3_family */
   4525 XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(const void* input, size_t len)
   4526 {
   4527     return XXH3_64bits_internal(input, len, 0, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_default);
   4528 }
   4529 
   4530 /*! @ingroup xxh3_family */
   4531 XXH_PUBLIC_API XXH64_hash_t
   4532 XXH3_64bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
   4533 {
   4534     return XXH3_64bits_internal(input, len, 0, secret, secretSize, XXH3_hashLong_64b_withSecret);
   4535 }
   4536 
   4537 /*! @ingroup xxh3_family */
   4538 XXH_PUBLIC_API XXH64_hash_t
   4539 XXH3_64bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
   4540 {
   4541     return XXH3_64bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_withSeed);
   4542 }
   4543 
   4544 
   4545 /* ===   XXH3 streaming   === */
   4546 
   4547 /*
   4548  * Malloc's a pointer that is always aligned to align.
   4549  *
   4550  * This must be freed with `XXH_alignedFree()`.
   4551  *
   4552  * malloc typically guarantees 16 byte alignment on 64-bit systems and 8 byte
   4553  * alignment on 32-bit. This isn't enough for the 32 byte aligned loads in AVX2
   4554  * or on 32-bit, the 16 byte aligned loads in SSE2 and NEON.
   4555  *
   4556  * This underalignment previously caused a rather obvious crash which went
   4557  * completely unnoticed due to XXH3_createState() not actually being tested.
   4558  * Credit to RedSpah for noticing this bug.
   4559  *
   4560  * The alignment is done manually: Functions like posix_memalign or _mm_malloc
   4561  * are avoided: To maintain portability, we would have to write a fallback
   4562  * like this anyways, and besides, testing for the existence of library
   4563  * functions without relying on external build tools is impossible.
   4564  *
   4565  * The method is simple: Overallocate, manually align, and store the offset
   4566  * to the original behind the returned pointer.
   4567  *
   4568  * Align must be a power of 2 and 8 <= align <= 128.
   4569  */
   4570 static void* XXH_alignedMalloc(size_t s, size_t align)
   4571 {
   4572     XXH_ASSERT(align <= 128 && align >= 8); /* range check */
   4573     XXH_ASSERT((align & (align-1)) == 0);   /* power of 2 */
   4574     XXH_ASSERT(s != 0 && s < (s + align));  /* empty/overflow */
   4575     {   /* Overallocate to make room for manual realignment and an offset byte */
   4576         xxh_u8* base = (xxh_u8*)XXH_malloc(s + align);
   4577         if (base != NULL) {
   4578             /*
   4579              * Get the offset needed to align this pointer.
   4580              *
   4581              * Even if the returned pointer is aligned, there will always be
   4582              * at least one byte to store the offset to the original pointer.
   4583              */
   4584             size_t offset = align - ((size_t)base & (align - 1)); /* base % align */
   4585             /* Add the offset for the now-aligned pointer */
   4586             xxh_u8* ptr = base + offset;
   4587 
   4588             XXH_ASSERT((size_t)ptr % align == 0);
   4589 
   4590             /* Store the offset immediately before the returned pointer. */
   4591             ptr[-1] = (xxh_u8)offset;
   4592             return ptr;
   4593         }
   4594         return NULL;
   4595     }
   4596 }
   4597 /*
   4598  * Frees an aligned pointer allocated by XXH_alignedMalloc(). Don't pass
   4599  * normal malloc'd pointers, XXH_alignedMalloc has a specific data layout.
   4600  */
   4601 static void XXH_alignedFree(void* p)
   4602 {
   4603     if (p != NULL) {
   4604         xxh_u8* ptr = (xxh_u8*)p;
   4605         /* Get the offset byte we added in XXH_malloc. */
   4606         xxh_u8 offset = ptr[-1];
   4607         /* Free the original malloc'd pointer */
   4608         xxh_u8* base = ptr - offset;
   4609         XXH_free(base);
   4610     }
   4611 }
   4612 /*! @ingroup xxh3_family */
   4613 XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void)
   4614 {
   4615     XXH3_state_t* const state = (XXH3_state_t*)XXH_alignedMalloc(sizeof(XXH3_state_t), 64);
   4616     if (state==NULL) return NULL;
   4617     XXH3_INITSTATE(state);
   4618     return state;
   4619 }
   4620 
   4621 /*! @ingroup xxh3_family */
   4622 XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr)
   4623 {
   4624     XXH_alignedFree(statePtr);
   4625     return XXH_OK;
   4626 }
   4627 
   4628 /*! @ingroup xxh3_family */
   4629 XXH_PUBLIC_API void
   4630 XXH3_copyState(XXH3_state_t* dst_state, const XXH3_state_t* src_state)
   4631 {
   4632     memcpy(dst_state, src_state, sizeof(*dst_state));
   4633 }
   4634 
   4635 static void
   4636 XXH3_reset_internal(XXH3_state_t* statePtr,
   4637                            XXH64_hash_t seed,
   4638                            const void* secret, size_t secretSize)
   4639 {
   4640     size_t const initStart = offsetof(XXH3_state_t, bufferedSize);
   4641     size_t const initLength = offsetof(XXH3_state_t, nbStripesPerBlock) - initStart;
   4642     XXH_ASSERT(offsetof(XXH3_state_t, nbStripesPerBlock) > initStart);
   4643     XXH_ASSERT(statePtr != NULL);
   4644     /* set members from bufferedSize to nbStripesPerBlock (excluded) to 0 */
   4645     memset((char*)statePtr + initStart, 0, initLength);
   4646     statePtr->acc[0] = XXH_PRIME32_3;
   4647     statePtr->acc[1] = XXH_PRIME64_1;
   4648     statePtr->acc[2] = XXH_PRIME64_2;
   4649     statePtr->acc[3] = XXH_PRIME64_3;
   4650     statePtr->acc[4] = XXH_PRIME64_4;
   4651     statePtr->acc[5] = XXH_PRIME32_2;
   4652     statePtr->acc[6] = XXH_PRIME64_5;
   4653     statePtr->acc[7] = XXH_PRIME32_1;
   4654     statePtr->seed = seed;
   4655     statePtr->extSecret = (const unsigned char*)secret;
   4656     XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
   4657     statePtr->secretLimit = secretSize - XXH_STRIPE_LEN;
   4658     statePtr->nbStripesPerBlock = statePtr->secretLimit / XXH_SECRET_CONSUME_RATE;
   4659 }
   4660 
   4661 /*! @ingroup xxh3_family */
   4662 XXH_PUBLIC_API XXH_errorcode
   4663 XXH3_64bits_reset(XXH3_state_t* statePtr)
   4664 {
   4665     if (statePtr == NULL) return XXH_ERROR;
   4666     XXH3_reset_internal(statePtr, 0, XXH3_kSecret, XXH_SECRET_DEFAULT_SIZE);
   4667     return XXH_OK;
   4668 }
   4669 
   4670 /*! @ingroup xxh3_family */
   4671 XXH_PUBLIC_API XXH_errorcode
   4672 XXH3_64bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
   4673 {
   4674     if (statePtr == NULL) return XXH_ERROR;
   4675     XXH3_reset_internal(statePtr, 0, secret, secretSize);
   4676     if (secret == NULL) return XXH_ERROR;
   4677     if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
   4678     return XXH_OK;
   4679 }
   4680 
   4681 /*! @ingroup xxh3_family */
   4682 XXH_PUBLIC_API XXH_errorcode
   4683 XXH3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
   4684 {
   4685     if (statePtr == NULL) return XXH_ERROR;
   4686     if (seed==0) return XXH3_64bits_reset(statePtr);
   4687     if (seed != statePtr->seed) XXH3_initCustomSecret(statePtr->customSecret, seed);
   4688     XXH3_reset_internal(statePtr, seed, NULL, XXH_SECRET_DEFAULT_SIZE);
   4689     return XXH_OK;
   4690 }
   4691 
   4692 /* Note : when XXH3_consumeStripes() is invoked,
   4693  * there must be a guarantee that at least one more byte must be consumed from input
   4694  * so that the function can blindly consume all stripes using the "normal" secret segment */
   4695 XXH_FORCE_INLINE void
   4696 XXH3_consumeStripes(xxh_u64* XXH_RESTRICT acc,
   4697                     size_t* XXH_RESTRICT nbStripesSoFarPtr, size_t nbStripesPerBlock,
   4698                     const xxh_u8* XXH_RESTRICT input, size_t nbStripes,
   4699                     const xxh_u8* XXH_RESTRICT secret, size_t secretLimit,
   4700                     XXH3_f_accumulate_512 f_acc512,
   4701                     XXH3_f_scrambleAcc f_scramble)
   4702 {
   4703     XXH_ASSERT(nbStripes <= nbStripesPerBlock);  /* can handle max 1 scramble per invocation */
   4704     XXH_ASSERT(*nbStripesSoFarPtr < nbStripesPerBlock);
   4705     if (nbStripesPerBlock - *nbStripesSoFarPtr <= nbStripes) {
   4706         /* need a scrambling operation */
   4707         size_t const nbStripesToEndofBlock = nbStripesPerBlock - *nbStripesSoFarPtr;
   4708         size_t const nbStripesAfterBlock = nbStripes - nbStripesToEndofBlock;
   4709         XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, nbStripesToEndofBlock, f_acc512);
   4710         f_scramble(acc, secret + secretLimit);
   4711         XXH3_accumulate(acc, input + nbStripesToEndofBlock * XXH_STRIPE_LEN, secret, nbStripesAfterBlock, f_acc512);
   4712         *nbStripesSoFarPtr = nbStripesAfterBlock;
   4713     } else {
   4714         XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, nbStripes, f_acc512);
   4715         *nbStripesSoFarPtr += nbStripes;
   4716     }
   4717 }
   4718 
   4719 /*
   4720  * Both XXH3_64bits_update and XXH3_128bits_update use this routine.
   4721  */
   4722 XXH_FORCE_INLINE XXH_errorcode
   4723 XXH3_update(XXH3_state_t* state,
   4724             const xxh_u8* input, size_t len,
   4725             XXH3_f_accumulate_512 f_acc512,
   4726             XXH3_f_scrambleAcc f_scramble)
   4727 {
   4728     if (input==NULL)
   4729 #if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && (XXH_ACCEPT_NULL_INPUT_POINTER>=1)
   4730         return XXH_OK;
   4731 #else
   4732         return XXH_ERROR;
   4733 #endif
   4734 
   4735     {   const xxh_u8* const bEnd = input + len;
   4736         const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
   4737 
   4738         state->totalLen += len;
   4739         XXH_ASSERT(state->bufferedSize <= XXH3_INTERNALBUFFER_SIZE);
   4740 
   4741         if (state->bufferedSize + len <= XXH3_INTERNALBUFFER_SIZE) {  /* fill in tmp buffer */
   4742             XXH_memcpy(state->buffer + state->bufferedSize, input, len);
   4743             state->bufferedSize += (XXH32_hash_t)len;
   4744             return XXH_OK;
   4745         }
   4746         /* total input is now > XXH3_INTERNALBUFFER_SIZE */
   4747 
   4748         #define XXH3_INTERNALBUFFER_STRIPES (XXH3_INTERNALBUFFER_SIZE / XXH_STRIPE_LEN)
   4749         XXH_STATIC_ASSERT(XXH3_INTERNALBUFFER_SIZE % XXH_STRIPE_LEN == 0);   /* clean multiple */
   4750 
   4751         /*
   4752          * Internal buffer is partially filled (always, except at beginning)
   4753          * Complete it, then consume it.
   4754          */
   4755         if (state->bufferedSize) {
   4756             size_t const loadSize = XXH3_INTERNALBUFFER_SIZE - state->bufferedSize;
   4757             XXH_memcpy(state->buffer + state->bufferedSize, input, loadSize);
   4758             input += loadSize;
   4759             XXH3_consumeStripes(state->acc,
   4760                                &state->nbStripesSoFar, state->nbStripesPerBlock,
   4761                                 state->buffer, XXH3_INTERNALBUFFER_STRIPES,
   4762                                 secret, state->secretLimit,
   4763                                 f_acc512, f_scramble);
   4764             state->bufferedSize = 0;
   4765         }
   4766         XXH_ASSERT(input < bEnd);
   4767 
   4768         /* Consume input by a multiple of internal buffer size */
   4769         if (input+XXH3_INTERNALBUFFER_SIZE < bEnd) {
   4770             const xxh_u8* const limit = bEnd - XXH3_INTERNALBUFFER_SIZE;
   4771             do {
   4772                 XXH3_consumeStripes(state->acc,
   4773                                    &state->nbStripesSoFar, state->nbStripesPerBlock,
   4774                                     input, XXH3_INTERNALBUFFER_STRIPES,
   4775                                     secret, state->secretLimit,
   4776                                     f_acc512, f_scramble);
   4777                 input += XXH3_INTERNALBUFFER_SIZE;
   4778             } while (input<limit);
   4779             /* for last partial stripe */
   4780             memcpy(state->buffer + sizeof(state->buffer) - XXH_STRIPE_LEN, input - XXH_STRIPE_LEN, XXH_STRIPE_LEN);
   4781         }
   4782         XXH_ASSERT(input < bEnd);
   4783 
   4784         /* Some remaining input (always) : buffer it */
   4785         XXH_memcpy(state->buffer, input, (size_t)(bEnd-input));
   4786         state->bufferedSize = (XXH32_hash_t)(bEnd-input);
   4787     }
   4788 
   4789     return XXH_OK;
   4790 }
   4791 
   4792 /*! @ingroup xxh3_family */
   4793 XXH_PUBLIC_API XXH_errorcode
   4794 XXH3_64bits_update(XXH3_state_t* state, const void* input, size_t len)
   4795 {
   4796     return XXH3_update(state, (const xxh_u8*)input, len,
   4797                        XXH3_accumulate_512, XXH3_scrambleAcc);
   4798 }
   4799 
   4800 
   4801 XXH_FORCE_INLINE void
   4802 XXH3_digest_long (XXH64_hash_t* acc,
   4803                   const XXH3_state_t* state,
   4804                   const unsigned char* secret)
   4805 {
   4806     /*
   4807      * Digest on a local copy. This way, the state remains unaltered, and it can
   4808      * continue ingesting more input afterwards.
   4809      */
   4810     memcpy(acc, state->acc, sizeof(state->acc));
   4811     if (state->bufferedSize >= XXH_STRIPE_LEN) {
   4812         size_t const nbStripes = (state->bufferedSize - 1) / XXH_STRIPE_LEN;
   4813         size_t nbStripesSoFar = state->nbStripesSoFar;
   4814         XXH3_consumeStripes(acc,
   4815                            &nbStripesSoFar, state->nbStripesPerBlock,
   4816                             state->buffer, nbStripes,
   4817                             secret, state->secretLimit,
   4818                             XXH3_accumulate_512, XXH3_scrambleAcc);
   4819         /* last stripe */
   4820         XXH3_accumulate_512(acc,
   4821                             state->buffer + state->bufferedSize - XXH_STRIPE_LEN,
   4822                             secret + state->secretLimit - XXH_SECRET_LASTACC_START);
   4823     } else {  /* bufferedSize < XXH_STRIPE_LEN */
   4824         xxh_u8 lastStripe[XXH_STRIPE_LEN];
   4825         size_t const catchupSize = XXH_STRIPE_LEN - state->bufferedSize;
   4826         XXH_ASSERT(state->bufferedSize > 0);  /* there is always some input buffered */
   4827         memcpy(lastStripe, state->buffer + sizeof(state->buffer) - catchupSize, catchupSize);
   4828         memcpy(lastStripe + catchupSize, state->buffer, state->bufferedSize);
   4829         XXH3_accumulate_512(acc,
   4830                             lastStripe,
   4831                             secret + state->secretLimit - XXH_SECRET_LASTACC_START);
   4832     }
   4833 }
   4834 
   4835 /*! @ingroup xxh3_family */
   4836 XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_digest (const XXH3_state_t* state)
   4837 {
   4838     const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
   4839     if (state->totalLen > XXH3_MIDSIZE_MAX) {
   4840         XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
   4841         XXH3_digest_long(acc, state, secret);
   4842         return XXH3_mergeAccs(acc,
   4843                               secret + XXH_SECRET_MERGEACCS_START,
   4844                               (xxh_u64)state->totalLen * XXH_PRIME64_1);
   4845     }
   4846     /* totalLen <= XXH3_MIDSIZE_MAX: digesting a short input */
   4847     if (state->seed)
   4848         return XXH3_64bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
   4849     return XXH3_64bits_withSecret(state->buffer, (size_t)(state->totalLen),
   4850                                   secret, state->secretLimit + XXH_STRIPE_LEN);
   4851 }
   4852 
   4853 
   4854 #define XXH_MIN(x, y) (((x) > (y)) ? (y) : (x))
   4855 
   4856 /*! @ingroup xxh3_family */
   4857 XXH_PUBLIC_API void
   4858 XXH3_generateSecret(void* secretBuffer, const void* customSeed, size_t customSeedSize)
   4859 {
   4860     XXH_ASSERT(secretBuffer != NULL);
   4861     if (customSeedSize == 0) {
   4862         memcpy(secretBuffer, XXH3_kSecret, XXH_SECRET_DEFAULT_SIZE);
   4863         return;
   4864     }
   4865     XXH_ASSERT(customSeed != NULL);
   4866 
   4867     {   size_t const segmentSize = sizeof(XXH128_hash_t);
   4868         size_t const nbSegments = XXH_SECRET_DEFAULT_SIZE / segmentSize;
   4869         XXH128_canonical_t scrambler;
   4870         XXH64_hash_t seeds[12];
   4871         size_t segnb;
   4872         XXH_ASSERT(nbSegments == 12);
   4873         XXH_ASSERT(segmentSize * nbSegments == XXH_SECRET_DEFAULT_SIZE); /* exact multiple */
   4874         XXH128_canonicalFromHash(&scrambler, XXH128(customSeed, customSeedSize, 0));
   4875 
   4876         /*
   4877         * Copy customSeed to seeds[], truncating or repeating as necessary.
   4878         */
   4879         {   size_t toFill = XXH_MIN(customSeedSize, sizeof(seeds));
   4880             size_t filled = toFill;
   4881             memcpy(seeds, customSeed, toFill);
   4882             while (filled < sizeof(seeds)) {
   4883                 toFill = XXH_MIN(filled, sizeof(seeds) - filled);
   4884                 memcpy((char*)seeds + filled, seeds, toFill);
   4885                 filled += toFill;
   4886         }   }
   4887 
   4888         /* generate secret */
   4889         memcpy(secretBuffer, &scrambler, sizeof(scrambler));
   4890         for (segnb=1; segnb < nbSegments; segnb++) {
   4891             size_t const segmentStart = segnb * segmentSize;
   4892             XXH128_canonical_t segment;
   4893             XXH128_canonicalFromHash(&segment,
   4894                 XXH128(&scrambler, sizeof(scrambler), XXH_readLE64(seeds + segnb) + segnb) );
   4895             memcpy((char*)secretBuffer + segmentStart, &segment, sizeof(segment));
   4896     }   }
   4897 }
   4898 
   4899 
   4900 /* ==========================================
   4901  * XXH3 128 bits (a.k.a XXH128)
   4902  * ==========================================
   4903  * XXH3's 128-bit variant has better mixing and strength than the 64-bit variant,
   4904  * even without counting the significantly larger output size.
   4905  *
   4906  * For example, extra steps are taken to avoid the seed-dependent collisions
   4907  * in 17-240 byte inputs (See XXH3_mix16B and XXH128_mix32B).
   4908  *
   4909  * This strength naturally comes at the cost of some speed, especially on short
   4910  * lengths. Note that longer hashes are about as fast as the 64-bit version
   4911  * due to it using only a slight modification of the 64-bit loop.
   4912  *
   4913  * XXH128 is also more oriented towards 64-bit machines. It is still extremely
   4914  * fast for a _128-bit_ hash on 32-bit (it usually clears XXH64).
   4915  */
   4916 
   4917 XXH_FORCE_INLINE XXH128_hash_t
   4918 XXH3_len_1to3_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   4919 {
   4920     /* A doubled version of 1to3_64b with different constants. */
   4921     XXH_ASSERT(input != NULL);
   4922     XXH_ASSERT(1 <= len && len <= 3);
   4923     XXH_ASSERT(secret != NULL);
   4924     /*
   4925      * len = 1: combinedl = { input[0], 0x01, input[0], input[0] }
   4926      * len = 2: combinedl = { input[1], 0x02, input[0], input[1] }
   4927      * len = 3: combinedl = { input[2], 0x03, input[0], input[1] }
   4928      */
   4929     {   xxh_u8 const c1 = input[0];
   4930         xxh_u8 const c2 = input[len >> 1];
   4931         xxh_u8 const c3 = input[len - 1];
   4932         xxh_u32 const combinedl = ((xxh_u32)c1 <<16) | ((xxh_u32)c2 << 24)
   4933                                 | ((xxh_u32)c3 << 0) | ((xxh_u32)len << 8);
   4934         xxh_u32 const combinedh = XXH_rotl32(XXH_swap32(combinedl), 13);
   4935         xxh_u64 const bitflipl = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
   4936         xxh_u64 const bitfliph = (XXH_readLE32(secret+8) ^ XXH_readLE32(secret+12)) - seed;
   4937         xxh_u64 const keyed_lo = (xxh_u64)combinedl ^ bitflipl;
   4938         xxh_u64 const keyed_hi = (xxh_u64)combinedh ^ bitfliph;
   4939         XXH128_hash_t h128;
   4940         h128.low64  = XXH64_avalanche(keyed_lo);
   4941         h128.high64 = XXH64_avalanche(keyed_hi);
   4942         return h128;
   4943     }
   4944 }
   4945 
   4946 XXH_FORCE_INLINE XXH128_hash_t
   4947 XXH3_len_4to8_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   4948 {
   4949     XXH_ASSERT(input != NULL);
   4950     XXH_ASSERT(secret != NULL);
   4951     XXH_ASSERT(4 <= len && len <= 8);
   4952     seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
   4953     {   xxh_u32 const input_lo = XXH_readLE32(input);
   4954         xxh_u32 const input_hi = XXH_readLE32(input + len - 4);
   4955         xxh_u64 const input_64 = input_lo + ((xxh_u64)input_hi << 32);
   4956         xxh_u64 const bitflip = (XXH_readLE64(secret+16) ^ XXH_readLE64(secret+24)) + seed;
   4957         xxh_u64 const keyed = input_64 ^ bitflip;
   4958 
   4959         /* Shift len to the left to ensure it is even, this avoids even multiplies. */
   4960         XXH128_hash_t m128 = XXH_mult64to128(keyed, XXH_PRIME64_1 + (len << 2));
   4961 
   4962         m128.high64 += (m128.low64 << 1);
   4963         m128.low64  ^= (m128.high64 >> 3);
   4964 
   4965         m128.low64   = XXH_xorshift64(m128.low64, 35);
   4966         m128.low64  *= 0x9FB21C651E98DF25ULL;
   4967         m128.low64   = XXH_xorshift64(m128.low64, 28);
   4968         m128.high64  = XXH3_avalanche(m128.high64);
   4969         return m128;
   4970     }
   4971 }
   4972 
   4973 XXH_FORCE_INLINE XXH128_hash_t
   4974 XXH3_len_9to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   4975 {
   4976     XXH_ASSERT(input != NULL);
   4977     XXH_ASSERT(secret != NULL);
   4978     XXH_ASSERT(9 <= len && len <= 16);
   4979     {   xxh_u64 const bitflipl = (XXH_readLE64(secret+32) ^ XXH_readLE64(secret+40)) - seed;
   4980         xxh_u64 const bitfliph = (XXH_readLE64(secret+48) ^ XXH_readLE64(secret+56)) + seed;
   4981         xxh_u64 const input_lo = XXH_readLE64(input);
   4982         xxh_u64       input_hi = XXH_readLE64(input + len - 8);
   4983         XXH128_hash_t m128 = XXH_mult64to128(input_lo ^ input_hi ^ bitflipl, XXH_PRIME64_1);
   4984         /*
   4985          * Put len in the middle of m128 to ensure that the length gets mixed to
   4986          * both the low and high bits in the 128x64 multiply below.
   4987          */
   4988         m128.low64 += (xxh_u64)(len - 1) << 54;
   4989         input_hi   ^= bitfliph;
   4990         /*
   4991          * Add the high 32 bits of input_hi to the high 32 bits of m128, then
   4992          * add the long product of the low 32 bits of input_hi and XXH_PRIME32_2 to
   4993          * the high 64 bits of m128.
   4994          *
   4995          * The best approach to this operation is different on 32-bit and 64-bit.
   4996          */
   4997         if (sizeof(void *) < sizeof(xxh_u64)) { /* 32-bit */
   4998             /*
   4999              * 32-bit optimized version, which is more readable.
   5000              *
   5001              * On 32-bit, it removes an ADC and delays a dependency between the two
   5002              * halves of m128.high64, but it generates an extra mask on 64-bit.
   5003              */
   5004             m128.high64 += (input_hi & 0xFFFFFFFF00000000ULL) + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2);
   5005         } else {
   5006             /*
   5007              * 64-bit optimized (albeit more confusing) version.
   5008              *
   5009              * Uses some properties of addition and multiplication to remove the mask:
   5010              *
   5011              * Let:
   5012              *    a = input_hi.lo = (input_hi & 0x00000000FFFFFFFF)
   5013              *    b = input_hi.hi = (input_hi & 0xFFFFFFFF00000000)
   5014              *    c = XXH_PRIME32_2
   5015              *
   5016              *    a + (b * c)
   5017              * Inverse Property: x + y - x == y
   5018              *    a + (b * (1 + c - 1))
   5019              * Distributive Property: x * (y + z) == (x * y) + (x * z)
   5020              *    a + (b * 1) + (b * (c - 1))
   5021              * Identity Property: x * 1 == x
   5022              *    a + b + (b * (c - 1))
   5023              *
   5024              * Substitute a, b, and c:
   5025              *    input_hi.hi + input_hi.lo + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
   5026              *
   5027              * Since input_hi.hi + input_hi.lo == input_hi, we get this:
   5028              *    input_hi + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
   5029              */
   5030             m128.high64 += input_hi + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2 - 1);
   5031         }
   5032         /* m128 ^= XXH_swap64(m128 >> 64); */
   5033         m128.low64  ^= XXH_swap64(m128.high64);
   5034 
   5035         {   /* 128x64 multiply: h128 = m128 * XXH_PRIME64_2; */
   5036             XXH128_hash_t h128 = XXH_mult64to128(m128.low64, XXH_PRIME64_2);
   5037             h128.high64 += m128.high64 * XXH_PRIME64_2;
   5038 
   5039             h128.low64   = XXH3_avalanche(h128.low64);
   5040             h128.high64  = XXH3_avalanche(h128.high64);
   5041             return h128;
   5042     }   }
   5043 }
   5044 
   5045 /*
   5046  * Assumption: `secret` size is >= XXH3_SECRET_SIZE_MIN
   5047  */
   5048 XXH_FORCE_INLINE XXH128_hash_t
   5049 XXH3_len_0to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
   5050 {
   5051     XXH_ASSERT(len <= 16);
   5052     {   if (len > 8) return XXH3_len_9to16_128b(input, len, secret, seed);
   5053         if (len >= 4) return XXH3_len_4to8_128b(input, len, secret, seed);
   5054         if (len) return XXH3_len_1to3_128b(input, len, secret, seed);
   5055         {   XXH128_hash_t h128;
   5056             xxh_u64 const bitflipl = XXH_readLE64(secret+64) ^ XXH_readLE64(secret+72);
   5057             xxh_u64 const bitfliph = XXH_readLE64(secret+80) ^ XXH_readLE64(secret+88);
   5058             h128.low64 = XXH64_avalanche(seed ^ bitflipl);
   5059             h128.high64 = XXH64_avalanche( seed ^ bitfliph);
   5060             return h128;
   5061     }   }
   5062 }
   5063 
   5064 /*
   5065  * A bit slower than XXH3_mix16B, but handles multiply by zero better.
   5066  */
   5067 XXH_FORCE_INLINE XXH128_hash_t
   5068 XXH128_mix32B(XXH128_hash_t acc, const xxh_u8* input_1, const xxh_u8* input_2,
   5069               const xxh_u8* secret, XXH64_hash_t seed)
   5070 {
   5071     acc.low64  += XXH3_mix16B (input_1, secret+0, seed);
   5072     acc.low64  ^= XXH_readLE64(input_2) + XXH_readLE64(input_2 + 8);
   5073     acc.high64 += XXH3_mix16B (input_2, secret+16, seed);
   5074     acc.high64 ^= XXH_readLE64(input_1) + XXH_readLE64(input_1 + 8);
   5075     return acc;
   5076 }
   5077 
   5078 
   5079 XXH_FORCE_INLINE XXH128_hash_t
   5080 XXH3_len_17to128_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
   5081                       const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
   5082                       XXH64_hash_t seed)
   5083 {
   5084     XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
   5085     XXH_ASSERT(16 < len && len <= 128);
   5086 
   5087     {   XXH128_hash_t acc;
   5088         acc.low64 = len * XXH_PRIME64_1;
   5089         acc.high64 = 0;
   5090         if (len > 32) {
   5091             if (len > 64) {
   5092                 if (len > 96) {
   5093                     acc = XXH128_mix32B(acc, input+48, input+len-64, secret+96, seed);
   5094                 }
   5095                 acc = XXH128_mix32B(acc, input+32, input+len-48, secret+64, seed);
   5096             }
   5097             acc = XXH128_mix32B(acc, input+16, input+len-32, secret+32, seed);
   5098         }
   5099         acc = XXH128_mix32B(acc, input, input+len-16, secret, seed);
   5100         {   XXH128_hash_t h128;
   5101             h128.low64  = acc.low64 + acc.high64;
   5102             h128.high64 = (acc.low64    * XXH_PRIME64_1)
   5103                         + (acc.high64   * XXH_PRIME64_4)
   5104                         + ((len - seed) * XXH_PRIME64_2);
   5105             h128.low64  = XXH3_avalanche(h128.low64);
   5106             h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
   5107             return h128;
   5108         }
   5109     }
   5110 }
   5111 
   5112 XXH_NO_INLINE XXH128_hash_t
   5113 XXH3_len_129to240_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
   5114                        const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
   5115                        XXH64_hash_t seed)
   5116 {
   5117     XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
   5118     XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
   5119 
   5120     {   XXH128_hash_t acc;
   5121         int const nbRounds = (int)len / 32;
   5122         int i;
   5123         acc.low64 = len * XXH_PRIME64_1;
   5124         acc.high64 = 0;
   5125         for (i=0; i<4; i++) {
   5126             acc = XXH128_mix32B(acc,
   5127                                 input  + (32 * i),
   5128                                 input  + (32 * i) + 16,
   5129                                 secret + (32 * i),
   5130                                 seed);
   5131         }
   5132         acc.low64 = XXH3_avalanche(acc.low64);
   5133         acc.high64 = XXH3_avalanche(acc.high64);
   5134         XXH_ASSERT(nbRounds >= 4);
   5135         for (i=4 ; i < nbRounds; i++) {
   5136             acc = XXH128_mix32B(acc,
   5137                                 input + (32 * i),
   5138                                 input + (32 * i) + 16,
   5139                                 secret + XXH3_MIDSIZE_STARTOFFSET + (32 * (i - 4)),
   5140                                 seed);
   5141         }
   5142         /* last bytes */
   5143         acc = XXH128_mix32B(acc,
   5144                             input + len - 16,
   5145                             input + len - 32,
   5146                             secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET - 16,
   5147                             0ULL - seed);
   5148 
   5149         {   XXH128_hash_t h128;
   5150             h128.low64  = acc.low64 + acc.high64;
   5151             h128.high64 = (acc.low64    * XXH_PRIME64_1)
   5152                         + (acc.high64   * XXH_PRIME64_4)
   5153                         + ((len - seed) * XXH_PRIME64_2);
   5154             h128.low64  = XXH3_avalanche(h128.low64);
   5155             h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
   5156             return h128;
   5157         }
   5158     }
   5159 }
   5160 
   5161 XXH_FORCE_INLINE XXH128_hash_t
   5162 XXH3_hashLong_128b_internal(const void* XXH_RESTRICT input, size_t len,
   5163                             const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
   5164                             XXH3_f_accumulate_512 f_acc512,
   5165                             XXH3_f_scrambleAcc f_scramble)
   5166 {
   5167     XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;
   5168 
   5169     XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, secret, secretSize, f_acc512, f_scramble);
   5170 
   5171     /* converge into final hash */
   5172     XXH_STATIC_ASSERT(sizeof(acc) == 64);
   5173     XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
   5174     {   XXH128_hash_t h128;
   5175         h128.low64  = XXH3_mergeAccs(acc,
   5176                                      secret + XXH_SECRET_MERGEACCS_START,
   5177                                      (xxh_u64)len * XXH_PRIME64_1);
   5178         h128.high64 = XXH3_mergeAccs(acc,
   5179                                      secret + secretSize
   5180                                             - sizeof(acc) - XXH_SECRET_MERGEACCS_START,
   5181                                      ~((xxh_u64)len * XXH_PRIME64_2));
   5182         return h128;
   5183     }
   5184 }
   5185 
   5186 /*
   5187  * It's important for performance that XXH3_hashLong is not inlined.
   5188  */
   5189 XXH_NO_INLINE XXH128_hash_t
   5190 XXH3_hashLong_128b_default(const void* XXH_RESTRICT input, size_t len,
   5191                            XXH64_hash_t seed64,
   5192                            const void* XXH_RESTRICT secret, size_t secretLen)
   5193 {
   5194     (void)seed64; (void)secret; (void)secretLen;
   5195     return XXH3_hashLong_128b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret),
   5196                                        XXH3_accumulate_512, XXH3_scrambleAcc);
   5197 }
   5198 
   5199 /*
   5200  * It's important for performance that XXH3_hashLong is not inlined.
   5201  */
   5202 XXH_NO_INLINE XXH128_hash_t
   5203 XXH3_hashLong_128b_withSecret(const void* XXH_RESTRICT input, size_t len,
   5204                               XXH64_hash_t seed64,
   5205                               const void* XXH_RESTRICT secret, size_t secretLen)
   5206 {
   5207     (void)seed64;
   5208     return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, secretLen,
   5209                                        XXH3_accumulate_512, XXH3_scrambleAcc);
   5210 }
   5211 
   5212 XXH_FORCE_INLINE XXH128_hash_t
   5213 XXH3_hashLong_128b_withSeed_internal(const void* XXH_RESTRICT input, size_t len,
   5214                                 XXH64_hash_t seed64,
   5215                                 XXH3_f_accumulate_512 f_acc512,
   5216                                 XXH3_f_scrambleAcc f_scramble,
   5217                                 XXH3_f_initCustomSecret f_initSec)
   5218 {
   5219     if (seed64 == 0)
   5220         return XXH3_hashLong_128b_internal(input, len,
   5221                                            XXH3_kSecret, sizeof(XXH3_kSecret),
   5222                                            f_acc512, f_scramble);
   5223     {   XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
   5224         f_initSec(secret, seed64);
   5225         return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, sizeof(secret),
   5226                                            f_acc512, f_scramble);
   5227     }
   5228 }
   5229 
   5230 /*
   5231  * It's important for performance that XXH3_hashLong is not inlined.
   5232  */
   5233 XXH_NO_INLINE XXH128_hash_t
   5234 XXH3_hashLong_128b_withSeed(const void* input, size_t len,
   5235                             XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen)
   5236 {
   5237     (void)secret; (void)secretLen;
   5238     return XXH3_hashLong_128b_withSeed_internal(input, len, seed64,
   5239                 XXH3_accumulate_512, XXH3_scrambleAcc, XXH3_initCustomSecret);
   5240 }
   5241 
   5242 typedef XXH128_hash_t (*XXH3_hashLong128_f)(const void* XXH_RESTRICT, size_t,
   5243                                             XXH64_hash_t, const void* XXH_RESTRICT, size_t);
   5244 
   5245 XXH_FORCE_INLINE XXH128_hash_t
   5246 XXH3_128bits_internal(const void* input, size_t len,
   5247                       XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
   5248                       XXH3_hashLong128_f f_hl128)
   5249 {
   5250     XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
   5251     /*
   5252      * If an action is to be taken if `secret` conditions are not respected,
   5253      * it should be done here.
   5254      * For now, it's a contract pre-condition.
   5255      * Adding a check and a branch here would cost performance at every hash.
   5256      */
   5257     if (len <= 16)
   5258         return XXH3_len_0to16_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
   5259     if (len <= 128)
   5260         return XXH3_len_17to128_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
   5261     if (len <= XXH3_MIDSIZE_MAX)
   5262         return XXH3_len_129to240_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
   5263     return f_hl128(input, len, seed64, secret, secretLen);
   5264 }
   5265 
   5266 
   5267 /* ===   Public XXH128 API   === */
   5268 
   5269 /*! @ingroup xxh3_family */
   5270 XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(const void* input, size_t len)
   5271 {
   5272     return XXH3_128bits_internal(input, len, 0,
   5273                                  XXH3_kSecret, sizeof(XXH3_kSecret),
   5274                                  XXH3_hashLong_128b_default);
   5275 }
   5276 
   5277 /*! @ingroup xxh3_family */
   5278 XXH_PUBLIC_API XXH128_hash_t
   5279 XXH3_128bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
   5280 {
   5281     return XXH3_128bits_internal(input, len, 0,
   5282                                  (const xxh_u8*)secret, secretSize,
   5283                                  XXH3_hashLong_128b_withSecret);
   5284 }
   5285 
   5286 /*! @ingroup xxh3_family */
   5287 XXH_PUBLIC_API XXH128_hash_t
   5288 XXH3_128bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
   5289 {
   5290     return XXH3_128bits_internal(input, len, seed,
   5291                                  XXH3_kSecret, sizeof(XXH3_kSecret),
   5292                                  XXH3_hashLong_128b_withSeed);
   5293 }
   5294 
   5295 /*! @ingroup xxh3_family */
   5296 XXH_PUBLIC_API XXH128_hash_t
   5297 XXH128(const void* input, size_t len, XXH64_hash_t seed)
   5298 {
   5299     return XXH3_128bits_withSeed(input, len, seed);
   5300 }
   5301 
   5302 
   5303 /* ===   XXH3 128-bit streaming   === */
   5304 
   5305 /*
   5306  * All the functions are actually the same as for 64-bit streaming variant.
   5307  * The only difference is the finalizatiom routine.
   5308  */
   5309 
   5310 /*! @ingroup xxh3_family */
   5311 XXH_PUBLIC_API XXH_errorcode
   5312 XXH3_128bits_reset(XXH3_state_t* statePtr)
   5313 {
   5314     if (statePtr == NULL) return XXH_ERROR;
   5315     XXH3_reset_internal(statePtr, 0, XXH3_kSecret, XXH_SECRET_DEFAULT_SIZE);
   5316     return XXH_OK;
   5317 }
   5318 
   5319 /*! @ingroup xxh3_family */
   5320 XXH_PUBLIC_API XXH_errorcode
   5321 XXH3_128bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
   5322 {
   5323     if (statePtr == NULL) return XXH_ERROR;
   5324     XXH3_reset_internal(statePtr, 0, secret, secretSize);
   5325     if (secret == NULL) return XXH_ERROR;
   5326     if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
   5327     return XXH_OK;
   5328 }
   5329 
   5330 /*! @ingroup xxh3_family */
   5331 XXH_PUBLIC_API XXH_errorcode
   5332 XXH3_128bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
   5333 {
   5334     if (statePtr == NULL) return XXH_ERROR;
   5335     if (seed==0) return XXH3_128bits_reset(statePtr);
   5336     if (seed != statePtr->seed) XXH3_initCustomSecret(statePtr->customSecret, seed);
   5337     XXH3_reset_internal(statePtr, seed, NULL, XXH_SECRET_DEFAULT_SIZE);
   5338     return XXH_OK;
   5339 }
   5340 
   5341 /*! @ingroup xxh3_family */
   5342 XXH_PUBLIC_API XXH_errorcode
   5343 XXH3_128bits_update(XXH3_state_t* state, const void* input, size_t len)
   5344 {
   5345     return XXH3_update(state, (const xxh_u8*)input, len,
   5346                        XXH3_accumulate_512, XXH3_scrambleAcc);
   5347 }
   5348 
   5349 /*! @ingroup xxh3_family */
   5350 XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (const XXH3_state_t* state)
   5351 {
   5352     const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
   5353     if (state->totalLen > XXH3_MIDSIZE_MAX) {
   5354         XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
   5355         XXH3_digest_long(acc, state, secret);
   5356         XXH_ASSERT(state->secretLimit + XXH_STRIPE_LEN >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
   5357         {   XXH128_hash_t h128;
   5358             h128.low64  = XXH3_mergeAccs(acc,
   5359                                          secret + XXH_SECRET_MERGEACCS_START,
   5360                                          (xxh_u64)state->totalLen * XXH_PRIME64_1);
   5361             h128.high64 = XXH3_mergeAccs(acc,
   5362                                          secret + state->secretLimit + XXH_STRIPE_LEN
   5363                                                 - sizeof(acc) - XXH_SECRET_MERGEACCS_START,
   5364                                          ~((xxh_u64)state->totalLen * XXH_PRIME64_2));
   5365             return h128;
   5366         }
   5367     }
   5368     /* len <= XXH3_MIDSIZE_MAX : short code */
   5369     if (state->seed)
   5370         return XXH3_128bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
   5371     return XXH3_128bits_withSecret(state->buffer, (size_t)(state->totalLen),
   5372                                    secret, state->secretLimit + XXH_STRIPE_LEN);
   5373 }
   5374 
   5375 /* 128-bit utility functions */
   5376 
   5377 #include <string.h>   /* memcmp, memcpy */
   5378 
   5379 /* return : 1 is equal, 0 if different */
   5380 /*! @ingroup xxh3_family */
   5381 XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2)
   5382 {
   5383     /* note : XXH128_hash_t is compact, it has no padding byte */
   5384     return !(memcmp(&h1, &h2, sizeof(h1)));
   5385 }
   5386 
   5387 /* This prototype is compatible with stdlib's qsort().
   5388  * return : >0 if *h128_1  > *h128_2
   5389  *          <0 if *h128_1  < *h128_2
   5390  *          =0 if *h128_1 == *h128_2  */
   5391 /*! @ingroup xxh3_family */
   5392 XXH_PUBLIC_API int XXH128_cmp(const void* h128_1, const void* h128_2)
   5393 {
   5394     XXH128_hash_t const h1 = *(const XXH128_hash_t*)h128_1;
   5395     XXH128_hash_t const h2 = *(const XXH128_hash_t*)h128_2;
   5396     int const hcmp = (h1.high64 > h2.high64) - (h2.high64 > h1.high64);
   5397     /* note : bets that, in most cases, hash values are different */
   5398     if (hcmp) return hcmp;
   5399     return (h1.low64 > h2.low64) - (h2.low64 > h1.low64);
   5400 }
   5401 
   5402 
   5403 /*======   Canonical representation   ======*/
   5404 /*! @ingroup xxh3_family */
   5405 XXH_PUBLIC_API void
   5406 XXH128_canonicalFromHash(XXH128_canonical_t* dst, XXH128_hash_t hash)
   5407 {
   5408     XXH_STATIC_ASSERT(sizeof(XXH128_canonical_t) == sizeof(XXH128_hash_t));
   5409     if (XXH_CPU_LITTLE_ENDIAN) {
   5410         hash.high64 = XXH_swap64(hash.high64);
   5411         hash.low64  = XXH_swap64(hash.low64);
   5412     }
   5413     memcpy(dst, &hash.high64, sizeof(hash.high64));
   5414     memcpy((char*)dst + sizeof(hash.high64), &hash.low64, sizeof(hash.low64));
   5415 }
   5416 
   5417 /*! @ingroup xxh3_family */
   5418 XXH_PUBLIC_API XXH128_hash_t
   5419 XXH128_hashFromCanonical(const XXH128_canonical_t* src)
   5420 {
   5421     XXH128_hash_t h;
   5422     h.high64 = XXH_readBE64(src);
   5423     h.low64  = XXH_readBE64(src->digest + 8);
   5424     return h;
   5425 }
   5426 
   5427 /* Pop our optimization override from above */
   5428 #if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
   5429   && defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
   5430   && defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
   5431 #  pragma GCC pop_options
   5432 #endif
   5433 
   5434 #endif  /* XXH_NO_LONG_LONG */
   5435 
   5436 /*!
   5437  * @}
   5438  */
   5439 #endif  /* XXH_IMPLEMENTATION */
   5440 
   5441 
   5442 #if defined (__cplusplus)
   5443 }
   5444 #endif