1/*
2 *  xxHash - Fast Hash algorithm
3 *  Copyright (c) Yann Collet, Facebook, Inc.
4 *
5 *  You can contact the author at :
6 *  - xxHash homepage: http://www.xxhash.com
7 *  - xxHash source repository : https://github.com/Cyan4973/xxHash
8 *
9 * This source code is licensed under both the BSD-style license (found in the
10 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
11 * in the COPYING file in the root directory of this source tree).
12 * You may select, at your option, one of the above-listed licenses.
13*/
14
15
16#ifndef XXH_NO_XXH3
17# define XXH_NO_XXH3
18#endif
19
20#ifndef XXH_NAMESPACE
21# define XXH_NAMESPACE ZSTD_
22#endif
23
24/*!
25 * @mainpage xxHash
26 *
27 * @file xxhash.h
28 * xxHash prototypes and implementation
29 */
30/* TODO: update */
31/* Notice extracted from xxHash homepage:
32
33xxHash is an extremely fast hash algorithm, running at RAM speed limits.
34It also successfully passes all tests from the SMHasher suite.
35
36Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
37
38Name            Speed       Q.Score   Author
39xxHash          5.4 GB/s     10
40CrapWow         3.2 GB/s      2       Andrew
41MurmurHash 3a   2.7 GB/s     10       Austin Appleby
42SpookyHash      2.0 GB/s     10       Bob Jenkins
43SBox            1.4 GB/s      9       Bret Mulvey
44Lookup3         1.2 GB/s      9       Bob Jenkins
45SuperFastHash   1.2 GB/s      1       Paul Hsieh
46CityHash64      1.05 GB/s    10       Pike & Alakuijala
47FNV             0.55 GB/s     5       Fowler, Noll, Vo
48CRC32           0.43 GB/s     9
49MD5-32          0.33 GB/s    10       Ronald L. Rivest
50SHA1-32         0.28 GB/s    10
51
52Q.Score is a measure of quality of the hash function.
53It depends on successfully passing SMHasher test set.
5410 is a perfect score.
55
56Note: SMHasher's CRC32 implementation is not the fastest one.
57Other speed-oriented implementations can be faster,
58especially in combination with PCLMUL instruction:
59https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html?showComment=1552696407071#c3490092340461170735
60
61A 64-bit version, named XXH64, is available since r35.
62It offers much better speed, but for 64-bit applications only.
63Name     Speed on 64 bits    Speed on 32 bits
64XXH64       13.8 GB/s            1.9 GB/s
65XXH32        6.8 GB/s            6.0 GB/s
66*/
67
68#if defined (__cplusplus)
69extern "C" {
70#endif
71
72/* ****************************
73 *  INLINE mode
74 ******************************/
75/*!
76 * XXH_INLINE_ALL (and XXH_PRIVATE_API)
77 * Use these build macros to inline xxhash into the target unit.
78 * Inlining improves performance on small inputs, especially when the length is
79 * expressed as a compile-time constant:
80 *
81 *      https://fastcompression.blogspot.com/2018/03/xxhash-for-small-keys-impressive-power.html
82 *
83 * It also keeps xxHash symbols private to the unit, so they are not exported.
84 *
85 * Usage:
86 *     #define XXH_INLINE_ALL
87 *     #include "xxhash.h"
88 *
89 * Do not compile and link xxhash.o as a separate object, as it is not useful.
90 */
91#if (defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)) \
92    && !defined(XXH_INLINE_ALL_31684351384)
93   /* this section should be traversed only once */
94#  define XXH_INLINE_ALL_31684351384
95   /* give access to the advanced API, required to compile implementations */
96#  undef XXH_STATIC_LINKING_ONLY   /* avoid macro redef */
97#  define XXH_STATIC_LINKING_ONLY
98   /* make all functions private */
99#  undef XXH_PUBLIC_API
100#  if defined(__GNUC__)
101#    define XXH_PUBLIC_API static __inline __attribute__((unused))
102#  elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
103#    define XXH_PUBLIC_API static inline
104#  elif defined(_MSC_VER)
105#    define XXH_PUBLIC_API static __inline
106#  else
107     /* note: this version may generate warnings for unused static functions */
108#    define XXH_PUBLIC_API static
109#  endif
110
111   /*
112    * This part deals with the special case where a unit wants to inline xxHash,
113    * but "xxhash.h" has previously been included without XXH_INLINE_ALL,
114    * such as part of some previously included *.h header file.
115    * Without further action, the new include would just be ignored,
116    * and functions would effectively _not_ be inlined (silent failure).
117    * The following macros solve this situation by prefixing all inlined names,
118    * avoiding naming collision with previous inclusions.
119    */
120   /* Before that, we unconditionally #undef all symbols,
121    * in case they were already defined with XXH_NAMESPACE.
122    * They will then be redefined for XXH_INLINE_ALL
123    */
124#  undef XXH_versionNumber
125    /* XXH32 */
126#  undef XXH32
127#  undef XXH32_createState
128#  undef XXH32_freeState
129#  undef XXH32_reset
130#  undef XXH32_update
131#  undef XXH32_digest
132#  undef XXH32_copyState
133#  undef XXH32_canonicalFromHash
134#  undef XXH32_hashFromCanonical
135    /* XXH64 */
136#  undef XXH64
137#  undef XXH64_createState
138#  undef XXH64_freeState
139#  undef XXH64_reset
140#  undef XXH64_update
141#  undef XXH64_digest
142#  undef XXH64_copyState
143#  undef XXH64_canonicalFromHash
144#  undef XXH64_hashFromCanonical
145    /* XXH3_64bits */
146#  undef XXH3_64bits
147#  undef XXH3_64bits_withSecret
148#  undef XXH3_64bits_withSeed
149#  undef XXH3_64bits_withSecretandSeed
150#  undef XXH3_createState
151#  undef XXH3_freeState
152#  undef XXH3_copyState
153#  undef XXH3_64bits_reset
154#  undef XXH3_64bits_reset_withSeed
155#  undef XXH3_64bits_reset_withSecret
156#  undef XXH3_64bits_update
157#  undef XXH3_64bits_digest
158#  undef XXH3_generateSecret
159    /* XXH3_128bits */
160#  undef XXH128
161#  undef XXH3_128bits
162#  undef XXH3_128bits_withSeed
163#  undef XXH3_128bits_withSecret
164#  undef XXH3_128bits_reset
165#  undef XXH3_128bits_reset_withSeed
166#  undef XXH3_128bits_reset_withSecret
167#  undef XXH3_128bits_reset_withSecretandSeed
168#  undef XXH3_128bits_update
169#  undef XXH3_128bits_digest
170#  undef XXH128_isEqual
171#  undef XXH128_cmp
172#  undef XXH128_canonicalFromHash
173#  undef XXH128_hashFromCanonical
174    /* Finally, free the namespace itself */
175#  undef XXH_NAMESPACE
176
177    /* employ the namespace for XXH_INLINE_ALL */
178#  define XXH_NAMESPACE XXH_INLINE_
179   /*
180    * Some identifiers (enums, type names) are not symbols,
181    * but they must nonetheless be renamed to avoid redeclaration.
182    * Alternative solution: do not redeclare them.
183    * However, this requires some #ifdefs, and has a more dispersed impact.
184    * Meanwhile, renaming can be achieved in a single place.
185    */
186#  define XXH_IPREF(Id)   XXH_NAMESPACE ## Id
187#  define XXH_OK XXH_IPREF(XXH_OK)
188#  define XXH_ERROR XXH_IPREF(XXH_ERROR)
189#  define XXH_errorcode XXH_IPREF(XXH_errorcode)
190#  define XXH32_canonical_t  XXH_IPREF(XXH32_canonical_t)
191#  define XXH64_canonical_t  XXH_IPREF(XXH64_canonical_t)
192#  define XXH128_canonical_t XXH_IPREF(XXH128_canonical_t)
193#  define XXH32_state_s XXH_IPREF(XXH32_state_s)
194#  define XXH32_state_t XXH_IPREF(XXH32_state_t)
195#  define XXH64_state_s XXH_IPREF(XXH64_state_s)
196#  define XXH64_state_t XXH_IPREF(XXH64_state_t)
197#  define XXH3_state_s  XXH_IPREF(XXH3_state_s)
198#  define XXH3_state_t  XXH_IPREF(XXH3_state_t)
199#  define XXH128_hash_t XXH_IPREF(XXH128_hash_t)
200   /* Ensure the header is parsed again, even if it was previously included */
201#  undef XXHASH_H_5627135585666179
202#  undef XXHASH_H_STATIC_13879238742
203#endif /* XXH_INLINE_ALL || XXH_PRIVATE_API */
204
205
206
207/* ****************************************************************
208 *  Stable API
209 *****************************************************************/
210#ifndef XXHASH_H_5627135585666179
211#define XXHASH_H_5627135585666179 1
212
213
214/*!
215 * @defgroup public Public API
216 * Contains details on the public xxHash functions.
217 * @{
218 */
219/* specific declaration modes for Windows */
220#if !defined(XXH_INLINE_ALL) && !defined(XXH_PRIVATE_API)
221#  if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
222#    ifdef XXH_EXPORT
223#      define XXH_PUBLIC_API __declspec(dllexport)
224#    elif XXH_IMPORT
225#      define XXH_PUBLIC_API __declspec(dllimport)
226#    endif
227#  else
228#    define XXH_PUBLIC_API   /* do nothing */
229#  endif
230#endif
231
232#ifdef XXH_DOXYGEN
233/*!
234 * @brief Emulate a namespace by transparently prefixing all symbols.
235 *
236 * If you want to include _and expose_ xxHash functions from within your own
237 * library, but also want to avoid symbol collisions with other libraries which
238 * may also include xxHash, you can use XXH_NAMESPACE to automatically prefix
239 * any public symbol from xxhash library with the value of XXH_NAMESPACE
240 * (therefore, avoid empty or numeric values).
241 *
242 * Note that no change is required within the calling program as long as it
243 * includes `xxhash.h`: Regular symbol names will be automatically translated
244 * by this header.
245 */
246#  define XXH_NAMESPACE /* YOUR NAME HERE */
247#  undef XXH_NAMESPACE
248#endif
249
250#ifdef XXH_NAMESPACE
251#  define XXH_CAT(A,B) A##B
252#  define XXH_NAME2(A,B) XXH_CAT(A,B)
253#  define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
254/* XXH32 */
255#  define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
256#  define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
257#  define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
258#  define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
259#  define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
260#  define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
261#  define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
262#  define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
263#  define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
264/* XXH64 */
265#  define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
266#  define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
267#  define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
268#  define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
269#  define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
270#  define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
271#  define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
272#  define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
273#  define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
274/* XXH3_64bits */
275#  define XXH3_64bits XXH_NAME2(XXH_NAMESPACE, XXH3_64bits)
276#  define XXH3_64bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSecret)
277#  define XXH3_64bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSeed)
278#  define XXH3_64bits_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSecretandSeed)
279#  define XXH3_createState XXH_NAME2(XXH_NAMESPACE, XXH3_createState)
280#  define XXH3_freeState XXH_NAME2(XXH_NAMESPACE, XXH3_freeState)
281#  define XXH3_copyState XXH_NAME2(XXH_NAMESPACE, XXH3_copyState)
282#  define XXH3_64bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset)
283#  define XXH3_64bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSeed)
284#  define XXH3_64bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSecret)
285#  define XXH3_64bits_reset_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSecretandSeed)
286#  define XXH3_64bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_update)
287#  define XXH3_64bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_digest)
288#  define XXH3_generateSecret XXH_NAME2(XXH_NAMESPACE, XXH3_generateSecret)
289#  define XXH3_generateSecret_fromSeed XXH_NAME2(XXH_NAMESPACE, XXH3_generateSecret_fromSeed)
290/* XXH3_128bits */
291#  define XXH128 XXH_NAME2(XXH_NAMESPACE, XXH128)
292#  define XXH3_128bits XXH_NAME2(XXH_NAMESPACE, XXH3_128bits)
293#  define XXH3_128bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSeed)
294#  define XXH3_128bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSecret)
295#  define XXH3_128bits_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSecretandSeed)
296#  define XXH3_128bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset)
297#  define XXH3_128bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSeed)
298#  define XXH3_128bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSecret)
299#  define XXH3_128bits_reset_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSecretandSeed)
300#  define XXH3_128bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_update)
301#  define XXH3_128bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_digest)
302#  define XXH128_isEqual XXH_NAME2(XXH_NAMESPACE, XXH128_isEqual)
303#  define XXH128_cmp     XXH_NAME2(XXH_NAMESPACE, XXH128_cmp)
304#  define XXH128_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH128_canonicalFromHash)
305#  define XXH128_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH128_hashFromCanonical)
306#endif
307
308
309/* *************************************
310*  Version
311***************************************/
312#define XXH_VERSION_MAJOR    0
313#define XXH_VERSION_MINOR    8
314#define XXH_VERSION_RELEASE  1
315#define XXH_VERSION_NUMBER  (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)
316
317/*!
318 * @brief Obtains the xxHash version.
319 *
320 * This is mostly useful when xxHash is compiled as a shared library,
321 * since the returned value comes from the library, as opposed to header file.
322 *
323 * @return `XXH_VERSION_NUMBER` of the invoked library.
324 */
325XXH_PUBLIC_API unsigned XXH_versionNumber (void);
326
327
328/* ****************************
329*  Common basic types
330******************************/
331#include <stddef.h>   /* size_t */
332typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
333
334
335/*-**********************************************************************
336*  32-bit hash
337************************************************************************/
338#if defined(XXH_DOXYGEN) /* Don't show <stdint.h> include */
339/*!
340 * @brief An unsigned 32-bit integer.
341 *
342 * Not necessarily defined to `uint32_t` but functionally equivalent.
343 */
344typedef uint32_t XXH32_hash_t;
345
346#elif !defined (__VMS) \
347  && (defined (__cplusplus) \
348  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
349#   include <stdint.h>
350    typedef uint32_t XXH32_hash_t;
351
352#else
353#   include <limits.h>
354#   if UINT_MAX == 0xFFFFFFFFUL
355      typedef unsigned int XXH32_hash_t;
356#   else
357#     if ULONG_MAX == 0xFFFFFFFFUL
358        typedef unsigned long XXH32_hash_t;
359#     else
360#       error "unsupported platform: need a 32-bit type"
361#     endif
362#   endif
363#endif
364
365/*!
366 * @}
367 *
368 * @defgroup xxh32_family XXH32 family
369 * @ingroup public
370 * Contains functions used in the classic 32-bit xxHash algorithm.
371 *
372 * @note
373 *   XXH32 is useful for older platforms, with no or poor 64-bit performance.
374 *   Note that @ref xxh3_family provides competitive speed
375 *   for both 32-bit and 64-bit systems, and offers true 64/128 bit hash results.
376 *
377 * @see @ref xxh64_family, @ref xxh3_family : Other xxHash families
378 * @see @ref xxh32_impl for implementation details
379 * @{
380 */
381
382/*!
383 * @brief Calculates the 32-bit hash of @p input using xxHash32.
384 *
385 * Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark): 5.4 GB/s
386 *
387 * @param input The block of data to be hashed, at least @p length bytes in size.
388 * @param length The length of @p input, in bytes.
389 * @param seed The 32-bit seed to alter the hash's output predictably.
390 *
391 * @pre
392 *   The memory between @p input and @p input + @p length must be valid,
393 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
394 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
395 *
396 * @return The calculated 32-bit hash value.
397 *
398 * @see
399 *    XXH64(), XXH3_64bits_withSeed(), XXH3_128bits_withSeed(), XXH128():
400 *    Direct equivalents for the other variants of xxHash.
401 * @see
402 *    XXH32_createState(), XXH32_update(), XXH32_digest(): Streaming version.
403 */
404XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t length, XXH32_hash_t seed);
405
406/*!
407 * Streaming functions generate the xxHash value from an incremental input.
408 * This method is slower than single-call functions, due to state management.
409 * For small inputs, prefer `XXH32()` and `XXH64()`, which are better optimized.
410 *
411 * An XXH state must first be allocated using `XXH*_createState()`.
412 *
413 * Start a new hash by initializing the state with a seed using `XXH*_reset()`.
414 *
415 * Then, feed the hash state by calling `XXH*_update()` as many times as necessary.
416 *
417 * The function returns an error code, with 0 meaning OK, and any other value
418 * meaning there is an error.
419 *
420 * Finally, a hash value can be produced anytime, by using `XXH*_digest()`.
421 * This function returns the nn-bits hash as an int or long long.
422 *
423 * It's still possible to continue inserting input into the hash state after a
424 * digest, and generate new hash values later on by invoking `XXH*_digest()`.
425 *
426 * When done, release the state using `XXH*_freeState()`.
427 *
428 * Example code for incrementally hashing a file:
429 * @code{.c}
430 *    #include <stdio.h>
431 *    #include <xxhash.h>
432 *    #define BUFFER_SIZE 256
433 *
434 *    // Note: XXH64 and XXH3 use the same interface.
435 *    XXH32_hash_t
436 *    hashFile(FILE* stream)
437 *    {
438 *        XXH32_state_t* state;
439 *        unsigned char buf[BUFFER_SIZE];
440 *        size_t amt;
441 *        XXH32_hash_t hash;
442 *
443 *        state = XXH32_createState();       // Create a state
444 *        assert(state != NULL);             // Error check here
445 *        XXH32_reset(state, 0xbaad5eed);    // Reset state with our seed
446 *        while ((amt = fread(buf, 1, sizeof(buf), stream)) != 0) {
447 *            XXH32_update(state, buf, amt); // Hash the file in chunks
448 *        }
449 *        hash = XXH32_digest(state);        // Finalize the hash
450 *        XXH32_freeState(state);            // Clean up
451 *        return hash;
452 *    }
453 * @endcode
454 */
455
456/*!
457 * @typedef struct XXH32_state_s XXH32_state_t
458 * @brief The opaque state struct for the XXH32 streaming API.
459 *
460 * @see XXH32_state_s for details.
461 */
462typedef struct XXH32_state_s XXH32_state_t;
463
464/*!
465 * @brief Allocates an @ref XXH32_state_t.
466 *
467 * Must be freed with XXH32_freeState().
468 * @return An allocated XXH32_state_t on success, `NULL` on failure.
469 */
470XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
471/*!
472 * @brief Frees an @ref XXH32_state_t.
473 *
474 * Must be allocated with XXH32_createState().
475 * @param statePtr A pointer to an @ref XXH32_state_t allocated with @ref XXH32_createState().
476 * @return XXH_OK.
477 */
478XXH_PUBLIC_API XXH_errorcode  XXH32_freeState(XXH32_state_t* statePtr);
479/*!
480 * @brief Copies one @ref XXH32_state_t to another.
481 *
482 * @param dst_state The state to copy to.
483 * @param src_state The state to copy from.
484 * @pre
485 *   @p dst_state and @p src_state must not be `NULL` and must not overlap.
486 */
487XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dst_state, const XXH32_state_t* src_state);
488
489/*!
490 * @brief Resets an @ref XXH32_state_t to begin a new hash.
491 *
492 * This function resets and seeds a state. Call it before @ref XXH32_update().
493 *
494 * @param statePtr The state struct to reset.
495 * @param seed The 32-bit seed to alter the hash result predictably.
496 *
497 * @pre
498 *   @p statePtr must not be `NULL`.
499 *
500 * @return @ref XXH_OK on success, @ref XXH_ERROR on failure.
501 */
502XXH_PUBLIC_API XXH_errorcode XXH32_reset  (XXH32_state_t* statePtr, XXH32_hash_t seed);
503
504/*!
505 * @brief Consumes a block of @p input to an @ref XXH32_state_t.
506 *
507 * Call this to incrementally consume blocks of data.
508 *
509 * @param statePtr The state struct to update.
510 * @param input The block of data to be hashed, at least @p length bytes in size.
511 * @param length The length of @p input, in bytes.
512 *
513 * @pre
514 *   @p statePtr must not be `NULL`.
515 * @pre
516 *   The memory between @p input and @p input + @p length must be valid,
517 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
518 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
519 *
520 * @return @ref XXH_OK on success, @ref XXH_ERROR on failure.
521 */
522XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
523
524/*!
525 * @brief Returns the calculated hash value from an @ref XXH32_state_t.
526 *
527 * @note
528 *   Calling XXH32_digest() will not affect @p statePtr, so you can update,
529 *   digest, and update again.
530 *
531 * @param statePtr The state struct to calculate the hash from.
532 *
533 * @pre
534 *  @p statePtr must not be `NULL`.
535 *
536 * @return The calculated xxHash32 value from that state.
537 */
538XXH_PUBLIC_API XXH32_hash_t  XXH32_digest (const XXH32_state_t* statePtr);
539
540/*******   Canonical representation   *******/
541
542/*
543 * The default return values from XXH functions are unsigned 32 and 64 bit
544 * integers.
545 * This the simplest and fastest format for further post-processing.
546 *
547 * However, this leaves open the question of what is the order on the byte level,
548 * since little and big endian conventions will store the same number differently.
549 *
550 * The canonical representation settles this issue by mandating big-endian
551 * convention, the same convention as human-readable numbers (large digits first).
552 *
553 * When writing hash values to storage, sending them over a network, or printing
554 * them, it's highly recommended to use the canonical representation to ensure
555 * portability across a wider range of systems, present and future.
556 *
557 * The following functions allow transformation of hash values to and from
558 * canonical format.
559 */
560
561/*!
562 * @brief Canonical (big endian) representation of @ref XXH32_hash_t.
563 */
564typedef struct {
565    unsigned char digest[4]; /*!< Hash bytes, big endian */
566} XXH32_canonical_t;
567
568/*!
569 * @brief Converts an @ref XXH32_hash_t to a big endian @ref XXH32_canonical_t.
570 *
571 * @param dst The @ref XXH32_canonical_t pointer to be stored to.
572 * @param hash The @ref XXH32_hash_t to be converted.
573 *
574 * @pre
575 *   @p dst must not be `NULL`.
576 */
577XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);
578
579/*!
580 * @brief Converts an @ref XXH32_canonical_t to a native @ref XXH32_hash_t.
581 *
582 * @param src The @ref XXH32_canonical_t to convert.
583 *
584 * @pre
585 *   @p src must not be `NULL`.
586 *
587 * @return The converted hash.
588 */
589XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
590
591
592#ifdef __has_attribute
593# define XXH_HAS_ATTRIBUTE(x) __has_attribute(x)
594#else
595# define XXH_HAS_ATTRIBUTE(x) 0
596#endif
597
598/* C-language Attributes are added in C23. */
599#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute)
600# define XXH_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
601#else
602# define XXH_HAS_C_ATTRIBUTE(x) 0
603#endif
604
605#if defined(__cplusplus) && defined(__has_cpp_attribute)
606# define XXH_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
607#else
608# define XXH_HAS_CPP_ATTRIBUTE(x) 0
609#endif
610
611/*
612Define XXH_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute
613introduced in CPP17 and C23.
614CPP17 : https://en.cppreference.com/w/cpp/language/attributes/fallthrough
615C23   : https://en.cppreference.com/w/c/language/attributes/fallthrough
616*/
617#if XXH_HAS_C_ATTRIBUTE(x)
618# define XXH_FALLTHROUGH [[fallthrough]]
619#elif XXH_HAS_CPP_ATTRIBUTE(x)
620# define XXH_FALLTHROUGH [[fallthrough]]
621#elif XXH_HAS_ATTRIBUTE(__fallthrough__)
622# define XXH_FALLTHROUGH __attribute__ ((fallthrough))
623#else
624# define XXH_FALLTHROUGH
625#endif
626
627/*!
628 * @}
629 * @ingroup public
630 * @{
631 */
632
633#ifndef XXH_NO_LONG_LONG
634/*-**********************************************************************
635*  64-bit hash
636************************************************************************/
637#if defined(XXH_DOXYGEN) /* don't include <stdint.h> */
638/*!
639 * @brief An unsigned 64-bit integer.
640 *
641 * Not necessarily defined to `uint64_t` but functionally equivalent.
642 */
643typedef uint64_t XXH64_hash_t;
644#elif !defined (__VMS) \
645  && (defined (__cplusplus) \
646  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
647#  include <stdint.h>
648   typedef uint64_t XXH64_hash_t;
649#else
650#  include <limits.h>
651#  if defined(__LP64__) && ULONG_MAX == 0xFFFFFFFFFFFFFFFFULL
652     /* LP64 ABI says uint64_t is unsigned long */
653     typedef unsigned long XXH64_hash_t;
654#  else
655     /* the following type must have a width of 64-bit */
656     typedef unsigned long long XXH64_hash_t;
657#  endif
658#endif
659
660/*!
661 * @}
662 *
663 * @defgroup xxh64_family XXH64 family
664 * @ingroup public
665 * @{
666 * Contains functions used in the classic 64-bit xxHash algorithm.
667 *
668 * @note
669 *   XXH3 provides competitive speed for both 32-bit and 64-bit systems,
670 *   and offers true 64/128 bit hash results.
671 *   It provides better speed for systems with vector processing capabilities.
672 */
673
674
675/*!
676 * @brief Calculates the 64-bit hash of @p input using xxHash64.
677 *
678 * This function usually runs faster on 64-bit systems, but slower on 32-bit
679 * systems (see benchmark).
680 *
681 * @param input The block of data to be hashed, at least @p length bytes in size.
682 * @param length The length of @p input, in bytes.
683 * @param seed The 64-bit seed to alter the hash's output predictably.
684 *
685 * @pre
686 *   The memory between @p input and @p input + @p length must be valid,
687 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
688 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
689 *
690 * @return The calculated 64-bit hash.
691 *
692 * @see
693 *    XXH32(), XXH3_64bits_withSeed(), XXH3_128bits_withSeed(), XXH128():
694 *    Direct equivalents for the other variants of xxHash.
695 * @see
696 *    XXH64_createState(), XXH64_update(), XXH64_digest(): Streaming version.
697 */
698/* Begin FreeBSD - This symbol is needed by dll-linked CLI zstd(1). */
699__attribute__((visibility ("default")))
700/* End FreeBSD */
701XXH_PUBLIC_API XXH64_hash_t XXH64(const void* input, size_t length, XXH64_hash_t seed);
702
703/*******   Streaming   *******/
704/*!
705 * @brief The opaque state struct for the XXH64 streaming API.
706 *
707 * @see XXH64_state_s for details.
708 */
709typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */
710XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);
711XXH_PUBLIC_API XXH_errorcode  XXH64_freeState(XXH64_state_t* statePtr);
712XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dst_state, const XXH64_state_t* src_state);
713
714XXH_PUBLIC_API XXH_errorcode XXH64_reset  (XXH64_state_t* statePtr, XXH64_hash_t seed);
715XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
716XXH_PUBLIC_API XXH64_hash_t  XXH64_digest (const XXH64_state_t* statePtr);
717
718/*******   Canonical representation   *******/
719typedef struct { unsigned char digest[sizeof(XXH64_hash_t)]; } XXH64_canonical_t;
720XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
721XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
722
723#ifndef XXH_NO_XXH3
724/*!
725 * @}
726 * ************************************************************************
727 * @defgroup xxh3_family XXH3 family
728 * @ingroup public
729 * @{
730 *
731 * XXH3 is a more recent hash algorithm featuring:
732 *  - Improved speed for both small and large inputs
733 *  - True 64-bit and 128-bit outputs
734 *  - SIMD acceleration
735 *  - Improved 32-bit viability
736 *
737 * Speed analysis methodology is explained here:
738 *
739 *    https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html
740 *
741 * Compared to XXH64, expect XXH3 to run approximately
742 * ~2x faster on large inputs and >3x faster on small ones,
743 * exact differences vary depending on platform.
744 *
745 * XXH3's speed benefits greatly from SIMD and 64-bit arithmetic,
746 * but does not require it.
747 * Any 32-bit and 64-bit targets that can run XXH32 smoothly
748 * can run XXH3 at competitive speeds, even without vector support.
749 * Further details are explained in the implementation.
750 *
751 * Optimized implementations are provided for AVX512, AVX2, SSE2, NEON, POWER8,
752 * ZVector and scalar targets. This can be controlled via the XXH_VECTOR macro.
753 *
754 * XXH3 implementation is portable:
755 * it has a generic C90 formulation that can be compiled on any platform,
756 * all implementations generage exactly the same hash value on all platforms.
757 * Starting from v0.8.0, it's also labelled "stable", meaning that
758 * any future version will also generate the same hash value.
759 *
760 * XXH3 offers 2 variants, _64bits and _128bits.
761 *
762 * When only 64 bits are needed, prefer invoking the _64bits variant, as it
763 * reduces the amount of mixing, resulting in faster speed on small inputs.
764 * It's also generally simpler to manipulate a scalar return type than a struct.
765 *
766 * The API supports one-shot hashing, streaming mode, and custom secrets.
767 */
768
769/*-**********************************************************************
770*  XXH3 64-bit variant
771************************************************************************/
772
773/* XXH3_64bits():
774 * default 64-bit variant, using default secret and default seed of 0.
775 * It's the fastest variant. */
776XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(const void* data, size_t len);
777
778/*
779 * XXH3_64bits_withSeed():
780 * This variant generates a custom secret on the fly
781 * based on default secret altered using the `seed` value.
782 * While this operation is decently fast, note that it's not completely free.
783 * Note: seed==0 produces the same results as XXH3_64bits().
784 */
785XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_withSeed(const void* data, size_t len, XXH64_hash_t seed);
786
787/*!
788 * The bare minimum size for a custom secret.
789 *
790 * @see
791 *  XXH3_64bits_withSecret(), XXH3_64bits_reset_withSecret(),
792 *  XXH3_128bits_withSecret(), XXH3_128bits_reset_withSecret().
793 */
794#define XXH3_SECRET_SIZE_MIN 136
795
796/*
797 * XXH3_64bits_withSecret():
798 * It's possible to provide any blob of bytes as a "secret" to generate the hash.
799 * This makes it more difficult for an external actor to prepare an intentional collision.
800 * The main condition is that secretSize *must* be large enough (>= XXH3_SECRET_SIZE_MIN).
801 * However, the quality of the secret impacts the dispersion of the hash algorithm.
802 * Therefore, the secret _must_ look like a bunch of random bytes.
803 * Avoid "trivial" or structured data such as repeated sequences or a text document.
804 * Whenever in doubt about the "randomness" of the blob of bytes,
805 * consider employing "XXH3_generateSecret()" instead (see below).
806 * It will generate a proper high entropy secret derived from the blob of bytes.
807 * Another advantage of using XXH3_generateSecret() is that
808 * it guarantees that all bits within the initial blob of bytes
809 * will impact every bit of the output.
810 * This is not necessarily the case when using the blob of bytes directly
811 * because, when hashing _small_ inputs, only a portion of the secret is employed.
812 */
813XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_withSecret(const void* data, size_t len, const void* secret, size_t secretSize);
814
815
816/*******   Streaming   *******/
817/*
818 * Streaming requires state maintenance.
819 * This operation costs memory and CPU.
820 * As a consequence, streaming is slower than one-shot hashing.
821 * For better performance, prefer one-shot functions whenever applicable.
822 */
823
824/*!
825 * @brief The state struct for the XXH3 streaming API.
826 *
827 * @see XXH3_state_s for details.
828 */
829typedef struct XXH3_state_s XXH3_state_t;
830XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void);
831XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr);
832XXH_PUBLIC_API void XXH3_copyState(XXH3_state_t* dst_state, const XXH3_state_t* src_state);
833
834/*
835 * XXH3_64bits_reset():
836 * Initialize with default parameters.
837 * digest will be equivalent to `XXH3_64bits()`.
838 */
839XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset(XXH3_state_t* statePtr);
840/*
841 * XXH3_64bits_reset_withSeed():
842 * Generate a custom secret from `seed`, and store it into `statePtr`.
843 * digest will be equivalent to `XXH3_64bits_withSeed()`.
844 */
845XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed);
846/*
847 * XXH3_64bits_reset_withSecret():
848 * `secret` is referenced, it _must outlive_ the hash streaming session.
849 * Similar to one-shot API, `secretSize` must be >= `XXH3_SECRET_SIZE_MIN`,
850 * and the quality of produced hash values depends on secret's entropy
851 * (secret's content should look like a bunch of random bytes).
852 * When in doubt about the randomness of a candidate `secret`,
853 * consider employing `XXH3_generateSecret()` instead (see below).
854 */
855XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize);
856
857XXH_PUBLIC_API XXH_errorcode XXH3_64bits_update (XXH3_state_t* statePtr, const void* input, size_t length);
858XXH_PUBLIC_API XXH64_hash_t  XXH3_64bits_digest (const XXH3_state_t* statePtr);
859
860/* note : canonical representation of XXH3 is the same as XXH64
861 * since they both produce XXH64_hash_t values */
862
863
864/*-**********************************************************************
865*  XXH3 128-bit variant
866************************************************************************/
867
868/*!
869 * @brief The return value from 128-bit hashes.
870 *
871 * Stored in little endian order, although the fields themselves are in native
872 * endianness.
873 */
874typedef struct {
875    XXH64_hash_t low64;   /*!< `value & 0xFFFFFFFFFFFFFFFF` */
876    XXH64_hash_t high64;  /*!< `value >> 64` */
877} XXH128_hash_t;
878
879XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(const void* data, size_t len);
880XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_withSeed(const void* data, size_t len, XXH64_hash_t seed);
881XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_withSecret(const void* data, size_t len, const void* secret, size_t secretSize);
882
883/*******   Streaming   *******/
884/*
885 * Streaming requires state maintenance.
886 * This operation costs memory and CPU.
887 * As a consequence, streaming is slower than one-shot hashing.
888 * For better performance, prefer one-shot functions whenever applicable.
889 *
890 * XXH3_128bits uses the same XXH3_state_t as XXH3_64bits().
891 * Use already declared XXH3_createState() and XXH3_freeState().
892 *
893 * All reset and streaming functions have same meaning as their 64-bit counterpart.
894 */
895
896XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset(XXH3_state_t* statePtr);
897XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed);
898XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize);
899
900XXH_PUBLIC_API XXH_errorcode XXH3_128bits_update (XXH3_state_t* statePtr, const void* input, size_t length);
901XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (const XXH3_state_t* statePtr);
902
903/* Following helper functions make it possible to compare XXH128_hast_t values.
904 * Since XXH128_hash_t is a structure, this capability is not offered by the language.
905 * Note: For better performance, these functions can be inlined using XXH_INLINE_ALL */
906
907/*!
908 * XXH128_isEqual():
909 * Return: 1 if `h1` and `h2` are equal, 0 if they are not.
910 */
911XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2);
912
913/*!
914 * XXH128_cmp():
915 *
916 * This comparator is compatible with stdlib's `qsort()`/`bsearch()`.
917 *
918 * return: >0 if *h128_1  > *h128_2
919 *         =0 if *h128_1 == *h128_2
920 *         <0 if *h128_1  < *h128_2
921 */
922XXH_PUBLIC_API int XXH128_cmp(const void* h128_1, const void* h128_2);
923
924
925/*******   Canonical representation   *******/
926typedef struct { unsigned char digest[sizeof(XXH128_hash_t)]; } XXH128_canonical_t;
927XXH_PUBLIC_API void XXH128_canonicalFromHash(XXH128_canonical_t* dst, XXH128_hash_t hash);
928XXH_PUBLIC_API XXH128_hash_t XXH128_hashFromCanonical(const XXH128_canonical_t* src);
929
930
931#endif  /* !XXH_NO_XXH3 */
932#endif  /* XXH_NO_LONG_LONG */
933
934/*!
935 * @}
936 */
937#endif /* XXHASH_H_5627135585666179 */
938
939
940
941#if defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742)
942#define XXHASH_H_STATIC_13879238742
943/* ****************************************************************************
944 * This section contains declarations which are not guaranteed to remain stable.
945 * They may change in future versions, becoming incompatible with a different
946 * version of the library.
947 * These declarations should only be used with static linking.
948 * Never use them in association with dynamic linking!
949 ***************************************************************************** */
950
951/*
952 * These definitions are only present to allow static allocation
953 * of XXH states, on stack or in a struct, for example.
954 * Never **ever** access their members directly.
955 */
956
957/*!
958 * @internal
959 * @brief Structure for XXH32 streaming API.
960 *
961 * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
962 * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
963 * an opaque type. This allows fields to safely be changed.
964 *
965 * Typedef'd to @ref XXH32_state_t.
966 * Do not access the members of this struct directly.
967 * @see XXH64_state_s, XXH3_state_s
968 */
969struct XXH32_state_s {
970   XXH32_hash_t total_len_32; /*!< Total length hashed, modulo 2^32 */
971   XXH32_hash_t large_len;    /*!< Whether the hash is >= 16 (handles @ref total_len_32 overflow) */
972   XXH32_hash_t v[4];         /*!< Accumulator lanes */
973   XXH32_hash_t mem32[4];     /*!< Internal buffer for partial reads. Treated as unsigned char[16]. */
974   XXH32_hash_t memsize;      /*!< Amount of data in @ref mem32 */
975   XXH32_hash_t reserved;     /*!< Reserved field. Do not read nor write to it. */
976};   /* typedef'd to XXH32_state_t */
977
978
979#ifndef XXH_NO_LONG_LONG  /* defined when there is no 64-bit support */
980
981/*!
982 * @internal
983 * @brief Structure for XXH64 streaming API.
984 *
985 * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
986 * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
987 * an opaque type. This allows fields to safely be changed.
988 *
989 * Typedef'd to @ref XXH64_state_t.
990 * Do not access the members of this struct directly.
991 * @see XXH32_state_s, XXH3_state_s
992 */
993struct XXH64_state_s {
994   XXH64_hash_t total_len;    /*!< Total length hashed. This is always 64-bit. */
995   XXH64_hash_t v[4];         /*!< Accumulator lanes */
996   XXH64_hash_t mem64[4];     /*!< Internal buffer for partial reads. Treated as unsigned char[32]. */
997   XXH32_hash_t memsize;      /*!< Amount of data in @ref mem64 */
998   XXH32_hash_t reserved32;   /*!< Reserved field, needed for padding anyways*/
999   XXH64_hash_t reserved64;   /*!< Reserved field. Do not read or write to it. */
1000};   /* typedef'd to XXH64_state_t */
1001
1002
1003#ifndef XXH_NO_XXH3
1004
1005#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* >= C11 */
1006#  include <stdalign.h>
1007#  define XXH_ALIGN(n)      alignas(n)
1008#elif defined(__cplusplus) && (__cplusplus >= 201103L) /* >= C++11 */
1009/* In C++ alignas() is a keyword */
1010#  define XXH_ALIGN(n)      alignas(n)
1011#elif defined(__GNUC__)
1012#  define XXH_ALIGN(n)      __attribute__ ((aligned(n)))
1013#elif defined(_MSC_VER)
1014#  define XXH_ALIGN(n)      __declspec(align(n))
1015#else
1016#  define XXH_ALIGN(n)   /* disabled */
1017#endif
1018
1019/* Old GCC versions only accept the attribute after the type in structures. */
1020#if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L))   /* C11+ */ \
1021    && ! (defined(__cplusplus) && (__cplusplus >= 201103L)) /* >= C++11 */ \
1022    && defined(__GNUC__)
1023#   define XXH_ALIGN_MEMBER(align, type) type XXH_ALIGN(align)
1024#else
1025#   define XXH_ALIGN_MEMBER(align, type) XXH_ALIGN(align) type
1026#endif
1027
1028/*!
1029 * @brief The size of the internal XXH3 buffer.
1030 *
1031 * This is the optimal update size for incremental hashing.
1032 *
1033 * @see XXH3_64b_update(), XXH3_128b_update().
1034 */
1035#define XXH3_INTERNALBUFFER_SIZE 256
1036
1037/*!
1038 * @brief Default size of the secret buffer (and @ref XXH3_kSecret).
1039 *
1040 * This is the size used in @ref XXH3_kSecret and the seeded functions.
1041 *
1042 * Not to be confused with @ref XXH3_SECRET_SIZE_MIN.
1043 */
1044#define XXH3_SECRET_DEFAULT_SIZE 192
1045
1046/*!
1047 * @internal
1048 * @brief Structure for XXH3 streaming API.
1049 *
1050 * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
1051 * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined.
1052 * Otherwise it is an opaque type.
1053 * Never use this definition in combination with dynamic library.
1054 * This allows fields to safely be changed in the future.
1055 *
1056 * @note ** This structure has a strict alignment requirement of 64 bytes!! **
1057 * Do not allocate this with `malloc()` or `new`,
1058 * it will not be sufficiently aligned.
1059 * Use @ref XXH3_createState() and @ref XXH3_freeState(), or stack allocation.
1060 *
1061 * Typedef'd to @ref XXH3_state_t.
1062 * Do never access the members of this struct directly.
1063 *
1064 * @see XXH3_INITSTATE() for stack initialization.
1065 * @see XXH3_createState(), XXH3_freeState().
1066 * @see XXH32_state_s, XXH64_state_s
1067 */
1068struct XXH3_state_s {
1069   XXH_ALIGN_MEMBER(64, XXH64_hash_t acc[8]);
1070       /*!< The 8 accumulators. Similar to `vN` in @ref XXH32_state_s::v1 and @ref XXH64_state_s */
1071   XXH_ALIGN_MEMBER(64, unsigned char customSecret[XXH3_SECRET_DEFAULT_SIZE]);
1072       /*!< Used to store a custom secret generated from a seed. */
1073   XXH_ALIGN_MEMBER(64, unsigned char buffer[XXH3_INTERNALBUFFER_SIZE]);
1074       /*!< The internal buffer. @see XXH32_state_s::mem32 */
1075   XXH32_hash_t bufferedSize;
1076       /*!< The amount of memory in @ref buffer, @see XXH32_state_s::memsize */
1077   XXH32_hash_t useSeed;
1078       /*!< Reserved field. Needed for padding on 64-bit. */
1079   size_t nbStripesSoFar;
1080       /*!< Number or stripes processed. */
1081   XXH64_hash_t totalLen;
1082       /*!< Total length hashed. 64-bit even on 32-bit targets. */
1083   size_t nbStripesPerBlock;
1084       /*!< Number of stripes per block. */
1085   size_t secretLimit;
1086       /*!< Size of @ref customSecret or @ref extSecret */
1087   XXH64_hash_t seed;
1088       /*!< Seed for _withSeed variants. Must be zero otherwise, @see XXH3_INITSTATE() */
1089   XXH64_hash_t reserved64;
1090       /*!< Reserved field. */
1091   const unsigned char* extSecret;
1092       /*!< Reference to an external secret for the _withSecret variants, NULL
1093        *   for other variants. */
1094   /* note: there may be some padding at the end due to alignment on 64 bytes */
1095}; /* typedef'd to XXH3_state_t */
1096
1097#undef XXH_ALIGN_MEMBER
1098
1099/*!
1100 * @brief Initializes a stack-allocated `XXH3_state_s`.
1101 *
1102 * When the @ref XXH3_state_t structure is merely emplaced on stack,
1103 * it should be initialized with XXH3_INITSTATE() or a memset()
1104 * in case its first reset uses XXH3_NNbits_reset_withSeed().
1105 * This init can be omitted if the first reset uses default or _withSecret mode.
1106 * This operation isn't necessary when the state is created with XXH3_createState().
1107 * Note that this doesn't prepare the state for a streaming operation,
1108 * it's still necessary to use XXH3_NNbits_reset*() afterwards.
1109 */
1110#define XXH3_INITSTATE(XXH3_state_ptr)   { (XXH3_state_ptr)->seed = 0; }
1111
1112
1113/* XXH128() :
1114 * simple alias to pre-selected XXH3_128bits variant
1115 */
1116XXH_PUBLIC_API XXH128_hash_t XXH128(const void* data, size_t len, XXH64_hash_t seed);
1117
1118
1119/* ===   Experimental API   === */
1120/* Symbols defined below must be considered tied to a specific library version. */
1121
1122/*
1123 * XXH3_generateSecret():
1124 *
1125 * Derive a high-entropy secret from any user-defined content, named customSeed.
1126 * The generated secret can be used in combination with `*_withSecret()` functions.
1127 * The `_withSecret()` variants are useful to provide a higher level of protection than 64-bit seed,
1128 * as it becomes much more difficult for an external actor to guess how to impact the calculation logic.
1129 *
1130 * The function accepts as input a custom seed of any length and any content,
1131 * and derives from it a high-entropy secret of length @secretSize
1132 * into an already allocated buffer @secretBuffer.
1133 * @secretSize must be >= XXH3_SECRET_SIZE_MIN
1134 *
1135 * The generated secret can then be used with any `*_withSecret()` variant.
1136 * Functions `XXH3_128bits_withSecret()`, `XXH3_64bits_withSecret()`,
1137 * `XXH3_128bits_reset_withSecret()` and `XXH3_64bits_reset_withSecret()`
1138 * are part of this list. They all accept a `secret` parameter
1139 * which must be large enough for implementation reasons (>= XXH3_SECRET_SIZE_MIN)
1140 * _and_ feature very high entropy (consist of random-looking bytes).
1141 * These conditions can be a high bar to meet, so
1142 * XXH3_generateSecret() can be employed to ensure proper quality.
1143 *
1144 * customSeed can be anything. It can have any size, even small ones,
1145 * and its content can be anything, even "poor entropy" sources such as a bunch of zeroes.
1146 * The resulting `secret` will nonetheless provide all required qualities.
1147 *
1148 * When customSeedSize > 0, supplying NULL as customSeed is undefined behavior.
1149 */
1150XXH_PUBLIC_API XXH_errorcode XXH3_generateSecret(void* secretBuffer, size_t secretSize, const void* customSeed, size_t customSeedSize);
1151
1152
1153/*
1154 * XXH3_generateSecret_fromSeed():
1155 *
1156 * Generate the same secret as the _withSeed() variants.
1157 *
1158 * The resulting secret has a length of XXH3_SECRET_DEFAULT_SIZE (necessarily).
1159 * @secretBuffer must be already allocated, of size at least XXH3_SECRET_DEFAULT_SIZE bytes.
1160 *
1161 * The generated secret can be used in combination with
1162 *`*_withSecret()` and `_withSecretandSeed()` variants.
1163 * This generator is notably useful in combination with `_withSecretandSeed()`,
1164 * as a way to emulate a faster `_withSeed()` variant.
1165 */
1166XXH_PUBLIC_API void XXH3_generateSecret_fromSeed(void* secretBuffer, XXH64_hash_t seed);
1167
1168/*
1169 * *_withSecretandSeed() :
1170 * These variants generate hash values using either
1171 * @seed for "short" keys (< XXH3_MIDSIZE_MAX = 240 bytes)
1172 * or @secret for "large" keys (>= XXH3_MIDSIZE_MAX).
1173 *
1174 * This generally benefits speed, compared to `_withSeed()` or `_withSecret()`.
1175 * `_withSeed()` has to generate the secret on the fly for "large" keys.
1176 * It's fast, but can be perceptible for "not so large" keys (< 1 KB).
1177 * `_withSecret()` has to generate the masks on the fly for "small" keys,
1178 * which requires more instructions than _withSeed() variants.
1179 * Therefore, _withSecretandSeed variant combines the best of both worlds.
1180 *
1181 * When @secret has been generated by XXH3_generateSecret_fromSeed(),
1182 * this variant produces *exactly* the same results as `_withSeed()` variant,
1183 * hence offering only a pure speed benefit on "large" input,
1184 * by skipping the need to regenerate the secret for every large input.
1185 *
1186 * Another usage scenario is to hash the secret to a 64-bit hash value,
1187 * for example with XXH3_64bits(), which then becomes the seed,
1188 * and then employ both the seed and the secret in _withSecretandSeed().
1189 * On top of speed, an added benefit is that each bit in the secret
1190 * has a 50% chance to swap each bit in the output,
1191 * via its impact to the seed.
1192 * This is not guaranteed when using the secret directly in "small data" scenarios,
1193 * because only portions of the secret are employed for small data.
1194 */
1195XXH_PUBLIC_API XXH64_hash_t
1196XXH3_64bits_withSecretandSeed(const void* data, size_t len,
1197                              const void* secret, size_t secretSize,
1198                              XXH64_hash_t seed);
1199
1200XXH_PUBLIC_API XXH128_hash_t
1201XXH3_128bits_withSecretandSeed(const void* data, size_t len,
1202                               const void* secret, size_t secretSize,
1203                               XXH64_hash_t seed64);
1204
1205XXH_PUBLIC_API XXH_errorcode
1206XXH3_64bits_reset_withSecretandSeed(XXH3_state_t* statePtr,
1207                                    const void* secret, size_t secretSize,
1208                                    XXH64_hash_t seed64);
1209
1210XXH_PUBLIC_API XXH_errorcode
1211XXH3_128bits_reset_withSecretandSeed(XXH3_state_t* statePtr,
1212                                     const void* secret, size_t secretSize,
1213                                     XXH64_hash_t seed64);
1214
1215
1216#endif  /* XXH_NO_XXH3 */
1217#endif  /* XXH_NO_LONG_LONG */
1218#if defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)
1219#  define XXH_IMPLEMENTATION
1220#endif
1221
1222#endif  /* defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742) */
1223
1224
1225/* ======================================================================== */
1226/* ======================================================================== */
1227/* ======================================================================== */
1228
1229
1230/*-**********************************************************************
1231 * xxHash implementation
1232 *-**********************************************************************
1233 * xxHash's implementation used to be hosted inside xxhash.c.
1234 *
1235 * However, inlining requires implementation to be visible to the compiler,
1236 * hence be included alongside the header.
1237 * Previously, implementation was hosted inside xxhash.c,
1238 * which was then #included when inlining was activated.
1239 * This construction created issues with a few build and install systems,
1240 * as it required xxhash.c to be stored in /include directory.
1241 *
1242 * xxHash implementation is now directly integrated within xxhash.h.
1243 * As a consequence, xxhash.c is no longer needed in /include.
1244 *
1245 * xxhash.c is still available and is still useful.
1246 * In a "normal" setup, when xxhash is not inlined,
1247 * xxhash.h only exposes the prototypes and public symbols,
1248 * while xxhash.c can be built into an object file xxhash.o
1249 * which can then be linked into the final binary.
1250 ************************************************************************/
1251
1252#if ( defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API) \
1253   || defined(XXH_IMPLEMENTATION) ) && !defined(XXH_IMPLEM_13a8737387)
1254#  define XXH_IMPLEM_13a8737387
1255
1256/* *************************************
1257*  Tuning parameters
1258***************************************/
1259
1260/*!
1261 * @defgroup tuning Tuning parameters
1262 * @{
1263 *
1264 * Various macros to control xxHash's behavior.
1265 */
1266#ifdef XXH_DOXYGEN
1267/*!
1268 * @brief Define this to disable 64-bit code.
1269 *
1270 * Useful if only using the @ref xxh32_family and you have a strict C90 compiler.
1271 */
1272#  define XXH_NO_LONG_LONG
1273#  undef XXH_NO_LONG_LONG /* don't actually */
1274/*!
1275 * @brief Controls how unaligned memory is accessed.
1276 *
1277 * By default, access to unaligned memory is controlled by `memcpy()`, which is
1278 * safe and portable.
1279 *
1280 * Unfortunately, on some target/compiler combinations, the generated assembly
1281 * is sub-optimal.
1282 *
1283 * The below switch allow selection of a different access method
1284 * in the search for improved performance.
1285 *
1286 * @par Possible options:
1287 *
1288 *  - `XXH_FORCE_MEMORY_ACCESS=0` (default): `memcpy`
1289 *   @par
1290 *     Use `memcpy()`. Safe and portable. Note that most modern compilers will
1291 *     eliminate the function call and treat it as an unaligned access.
1292 *
1293 *  - `XXH_FORCE_MEMORY_ACCESS=1`: `__attribute__((packed))`
1294 *   @par
1295 *     Depends on compiler extensions and is therefore not portable.
1296 *     This method is safe _if_ your compiler supports it,
1297 *     and *generally* as fast or faster than `memcpy`.
1298 *
1299 *  - `XXH_FORCE_MEMORY_ACCESS=2`: Direct cast
1300 *  @par
1301 *     Casts directly and dereferences. This method doesn't depend on the
1302 *     compiler, but it violates the C standard as it directly dereferences an
1303 *     unaligned pointer. It can generate buggy code on targets which do not
1304 *     support unaligned memory accesses, but in some circumstances, it's the
1305 *     only known way to get the most performance.
1306 *
1307 *  - `XXH_FORCE_MEMORY_ACCESS=3`: Byteshift
1308 *  @par
1309 *     Also portable. This can generate the best code on old compilers which don't
1310 *     inline small `memcpy()` calls, and it might also be faster on big-endian
1311 *     systems which lack a native byteswap instruction. However, some compilers
1312 *     will emit literal byteshifts even if the target supports unaligned access.
1313 *  .
1314 *
1315 * @warning
1316 *   Methods 1 and 2 rely on implementation-defined behavior. Use these with
1317 *   care, as what works on one compiler/platform/optimization level may cause
1318 *   another to read garbage data or even crash.
1319 *
1320 * See http://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html for details.
1321 *
1322 * Prefer these methods in priority order (0 > 3 > 1 > 2)
1323 */
1324#  define XXH_FORCE_MEMORY_ACCESS 0
1325
1326/*!
1327 * @def XXH_FORCE_ALIGN_CHECK
1328 * @brief If defined to non-zero, adds a special path for aligned inputs (XXH32()
1329 * and XXH64() only).
1330 *
1331 * This is an important performance trick for architectures without decent
1332 * unaligned memory access performance.
1333 *
1334 * It checks for input alignment, and when conditions are met, uses a "fast
1335 * path" employing direct 32-bit/64-bit reads, resulting in _dramatically
1336 * faster_ read speed.
1337 *
1338 * The check costs one initial branch per hash, which is generally negligible,
1339 * but not zero.
1340 *
1341 * Moreover, it's not useful to generate an additional code path if memory
1342 * access uses the same instruction for both aligned and unaligned
1343 * addresses (e.g. x86 and aarch64).
1344 *
1345 * In these cases, the alignment check can be removed by setting this macro to 0.
1346 * Then the code will always use unaligned memory access.
1347 * Align check is automatically disabled on x86, x64 & arm64,
1348 * which are platforms known to offer good unaligned memory accesses performance.
1349 *
1350 * This option does not affect XXH3 (only XXH32 and XXH64).
1351 */
1352#  define XXH_FORCE_ALIGN_CHECK 0
1353
1354/*!
1355 * @def XXH_NO_INLINE_HINTS
1356 * @brief When non-zero, sets all functions to `static`.
1357 *
1358 * By default, xxHash tries to force the compiler to inline almost all internal
1359 * functions.
1360 *
1361 * This can usually improve performance due to reduced jumping and improved
1362 * constant folding, but significantly increases the size of the binary which
1363 * might not be favorable.
1364 *
1365 * Additionally, sometimes the forced inlining can be detrimental to performance,
1366 * depending on the architecture.
1367 *
1368 * XXH_NO_INLINE_HINTS marks all internal functions as static, giving the
1369 * compiler full control on whether to inline or not.
1370 *
1371 * When not optimizing (-O0), optimizing for size (-Os, -Oz), or using
1372 * -fno-inline with GCC or Clang, this will automatically be defined.
1373 */
1374#  define XXH_NO_INLINE_HINTS 0
1375
1376/*!
1377 * @def XXH32_ENDJMP
1378 * @brief Whether to use a jump for `XXH32_finalize`.
1379 *
1380 * For performance, `XXH32_finalize` uses multiple branches in the finalizer.
1381 * This is generally preferable for performance,
1382 * but depending on exact architecture, a jmp may be preferable.
1383 *
1384 * This setting is only possibly making a difference for very small inputs.
1385 */
1386#  define XXH32_ENDJMP 0
1387
1388/*!
1389 * @internal
1390 * @brief Redefines old internal names.
1391 *
1392 * For compatibility with code that uses xxHash's internals before the names
1393 * were changed to improve namespacing. There is no other reason to use this.
1394 */
1395#  define XXH_OLD_NAMES
1396#  undef XXH_OLD_NAMES /* don't actually use, it is ugly. */
1397#endif /* XXH_DOXYGEN */
1398/*!
1399 * @}
1400 */
1401
1402#ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
1403   /* prefer __packed__ structures (method 1) for gcc on armv7+ and mips */
1404#  if !defined(__clang__) && \
1405( \
1406    (defined(__INTEL_COMPILER) && !defined(_WIN32)) || \
1407    ( \
1408        defined(__GNUC__) && ( \
1409            (defined(__ARM_ARCH) && __ARM_ARCH >= 7) || \
1410            ( \
1411                defined(__mips__) && \
1412                (__mips <= 5 || __mips_isa_rev < 6) && \
1413                (!defined(__mips16) || defined(__mips_mips16e2)) \
1414            ) \
1415        ) \
1416    ) \
1417)
1418#    define XXH_FORCE_MEMORY_ACCESS 1
1419#  endif
1420#endif
1421
1422#ifndef XXH_FORCE_ALIGN_CHECK  /* can be defined externally */
1423#  if defined(__i386)  || defined(__x86_64__) || defined(__aarch64__) \
1424   || defined(_M_IX86) || defined(_M_X64)     || defined(_M_ARM64) /* visual */
1425#    define XXH_FORCE_ALIGN_CHECK 0
1426#  else
1427#    define XXH_FORCE_ALIGN_CHECK 1
1428#  endif
1429#endif
1430
1431#ifndef XXH_NO_INLINE_HINTS
1432#  if defined(__OPTIMIZE_SIZE__) /* -Os, -Oz */ \
1433   || defined(__NO_INLINE__)     /* -O0, -fno-inline */
1434#    define XXH_NO_INLINE_HINTS 1
1435#  else
1436#    define XXH_NO_INLINE_HINTS 0
1437#  endif
1438#endif
1439
1440#ifndef XXH32_ENDJMP
1441/* generally preferable for performance */
1442#  define XXH32_ENDJMP 0
1443#endif
1444
1445/*!
1446 * @defgroup impl Implementation
1447 * @{
1448 */
1449
1450
1451/* *************************************
1452*  Includes & Memory related functions
1453***************************************/
1454/* Modify the local functions below should you wish to use some other memory routines */
1455/* for ZSTD_malloc(), ZSTD_free() */
1456#define ZSTD_DEPS_NEED_MALLOC
1457#include "zstd_deps.h"  /* size_t, ZSTD_malloc, ZSTD_free, ZSTD_memcpy */
1458static void* XXH_malloc(size_t s) { return ZSTD_malloc(s); }
1459static void  XXH_free  (void* p)  { ZSTD_free(p); }
1460static void* XXH_memcpy(void* dest, const void* src, size_t size) { return ZSTD_memcpy(dest,src,size); }
1461
1462
1463/* *************************************
1464*  Compiler Specific Options
1465***************************************/
1466#ifdef _MSC_VER /* Visual Studio warning fix */
1467#  pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
1468#endif
1469
1470#if XXH_NO_INLINE_HINTS  /* disable inlining hints */
1471#  if defined(__GNUC__) || defined(__clang__)
1472#    define XXH_FORCE_INLINE static __attribute__((unused))
1473#  else
1474#    define XXH_FORCE_INLINE static
1475#  endif
1476#  define XXH_NO_INLINE static
1477/* enable inlining hints */
1478#elif defined(__GNUC__) || defined(__clang__)
1479#  define XXH_FORCE_INLINE static __inline__ __attribute__((always_inline, unused))
1480#  define XXH_NO_INLINE static __attribute__((noinline))
1481#elif defined(_MSC_VER)  /* Visual Studio */
1482#  define XXH_FORCE_INLINE static __forceinline
1483#  define XXH_NO_INLINE static __declspec(noinline)
1484#elif defined (__cplusplus) \
1485  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L))   /* C99 */
1486#  define XXH_FORCE_INLINE static inline
1487#  define XXH_NO_INLINE static
1488#else
1489#  define XXH_FORCE_INLINE static
1490#  define XXH_NO_INLINE static
1491#endif
1492
1493
1494
1495/* *************************************
1496*  Debug
1497***************************************/
1498/*!
1499 * @ingroup tuning
1500 * @def XXH_DEBUGLEVEL
1501 * @brief Sets the debugging level.
1502 *
1503 * XXH_DEBUGLEVEL is expected to be defined externally, typically via the
1504 * compiler's command line options. The value must be a number.
1505 */
1506#ifndef XXH_DEBUGLEVEL
1507#  ifdef DEBUGLEVEL /* backwards compat */
1508#    define XXH_DEBUGLEVEL DEBUGLEVEL
1509#  else
1510#    define XXH_DEBUGLEVEL 0
1511#  endif
1512#endif
1513
1514#if (XXH_DEBUGLEVEL>=1)
1515#  include <assert.h>   /* note: can still be disabled with NDEBUG */
1516#  define XXH_ASSERT(c)   assert(c)
1517#else
1518#  define XXH_ASSERT(c)   ((void)0)
1519#endif
1520
1521/* note: use after variable declarations */
1522#ifndef XXH_STATIC_ASSERT
1523#  if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)    /* C11 */
1524#    include <assert.h>
1525#    define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { static_assert((c),m); } while(0)
1526#  elif defined(__cplusplus) && (__cplusplus >= 201103L)            /* C++11 */
1527#    define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { static_assert((c),m); } while(0)
1528#  else
1529#    define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { struct xxh_sa { char x[(c) ? 1 : -1]; }; } while(0)
1530#  endif
1531#  define XXH_STATIC_ASSERT(c) XXH_STATIC_ASSERT_WITH_MESSAGE((c),#c)
1532#endif
1533
1534/*!
1535 * @internal
1536 * @def XXH_COMPILER_GUARD(var)
1537 * @brief Used to prevent unwanted optimizations for @p var.
1538 *
1539 * It uses an empty GCC inline assembly statement with a register constraint
1540 * which forces @p var into a general purpose register (eg eax, ebx, ecx
1541 * on x86) and marks it as modified.
1542 *
1543 * This is used in a few places to avoid unwanted autovectorization (e.g.
1544 * XXH32_round()). All vectorization we want is explicit via intrinsics,
1545 * and _usually_ isn't wanted elsewhere.
1546 *
1547 * We also use it to prevent unwanted constant folding for AArch64 in
1548 * XXH3_initCustomSecret_scalar().
1549 */
1550#if defined(__GNUC__) || defined(__clang__)
1551#  define XXH_COMPILER_GUARD(var) __asm__ __volatile__("" : "+r" (var))
1552#else
1553#  define XXH_COMPILER_GUARD(var) ((void)0)
1554#endif
1555
1556/* *************************************
1557*  Basic Types
1558***************************************/
1559#if !defined (__VMS) \
1560 && (defined (__cplusplus) \
1561 || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
1562# include <stdint.h>
1563  typedef uint8_t xxh_u8;
1564#else
1565  typedef unsigned char xxh_u8;
1566#endif
1567typedef XXH32_hash_t xxh_u32;
1568
1569#ifdef XXH_OLD_NAMES
1570#  define BYTE xxh_u8
1571#  define U8   xxh_u8
1572#  define U32  xxh_u32
1573#endif
1574
1575/* ***   Memory access   *** */
1576
1577/*!
1578 * @internal
1579 * @fn xxh_u32 XXH_read32(const void* ptr)
1580 * @brief Reads an unaligned 32-bit integer from @p ptr in native endianness.
1581 *
1582 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1583 *
1584 * @param ptr The pointer to read from.
1585 * @return The 32-bit native endian integer from the bytes at @p ptr.
1586 */
1587
1588/*!
1589 * @internal
1590 * @fn xxh_u32 XXH_readLE32(const void* ptr)
1591 * @brief Reads an unaligned 32-bit little endian integer from @p ptr.
1592 *
1593 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1594 *
1595 * @param ptr The pointer to read from.
1596 * @return The 32-bit little endian integer from the bytes at @p ptr.
1597 */
1598
1599/*!
1600 * @internal
1601 * @fn xxh_u32 XXH_readBE32(const void* ptr)
1602 * @brief Reads an unaligned 32-bit big endian integer from @p ptr.
1603 *
1604 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1605 *
1606 * @param ptr The pointer to read from.
1607 * @return The 32-bit big endian integer from the bytes at @p ptr.
1608 */
1609
1610/*!
1611 * @internal
1612 * @fn xxh_u32 XXH_readLE32_align(const void* ptr, XXH_alignment align)
1613 * @brief Like @ref XXH_readLE32(), but has an option for aligned reads.
1614 *
1615 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
1616 * Note that when @ref XXH_FORCE_ALIGN_CHECK == 0, the @p align parameter is
1617 * always @ref XXH_alignment::XXH_unaligned.
1618 *
1619 * @param ptr The pointer to read from.
1620 * @param align Whether @p ptr is aligned.
1621 * @pre
1622 *   If @p align == @ref XXH_alignment::XXH_aligned, @p ptr must be 4 byte
1623 *   aligned.
1624 * @return The 32-bit little endian integer from the bytes at @p ptr.
1625 */
1626
1627#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
1628/*
1629 * Manual byteshift. Best for old compilers which don't inline memcpy.
1630 * We actually directly use XXH_readLE32 and XXH_readBE32.
1631 */
1632#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
1633
1634/*
1635 * Force direct memory access. Only works on CPU which support unaligned memory
1636 * access in hardware.
1637 */
1638static xxh_u32 XXH_read32(const void* memPtr) { return *(const xxh_u32*) memPtr; }
1639
1640#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
1641
1642/*
1643 * __pack instructions are safer but compiler specific, hence potentially
1644 * problematic for some compilers.
1645 *
1646 * Currently only defined for GCC and ICC.
1647 */
1648#ifdef XXH_OLD_NAMES
1649typedef union { xxh_u32 u32; } __attribute__((packed)) unalign;
1650#endif
1651static xxh_u32 XXH_read32(const void* ptr)
1652{
1653    typedef union { xxh_u32 u32; } __attribute__((packed)) xxh_unalign;
1654    return ((const xxh_unalign*)ptr)->u32;
1655}
1656
1657#else
1658
1659/*
1660 * Portable and safe solution. Generally efficient.
1661 * see: http://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html
1662 */
1663static xxh_u32 XXH_read32(const void* memPtr)
1664{
1665    xxh_u32 val;
1666    XXH_memcpy(&val, memPtr, sizeof(val));
1667    return val;
1668}
1669
1670#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
1671
1672
1673/* ***   Endianness   *** */
1674
1675/*!
1676 * @ingroup tuning
1677 * @def XXH_CPU_LITTLE_ENDIAN
1678 * @brief Whether the target is little endian.
1679 *
1680 * Defined to 1 if the target is little endian, or 0 if it is big endian.
1681 * It can be defined externally, for example on the compiler command line.
1682 *
1683 * If it is not defined,
1684 * a runtime check (which is usually constant folded) is used instead.
1685 *
1686 * @note
1687 *   This is not necessarily defined to an integer constant.
1688 *
1689 * @see XXH_isLittleEndian() for the runtime check.
1690 */
1691#ifndef XXH_CPU_LITTLE_ENDIAN
1692/*
1693 * Try to detect endianness automatically, to avoid the nonstandard behavior
1694 * in `XXH_isLittleEndian()`
1695 */
1696#  if defined(_WIN32) /* Windows is always little endian */ \
1697     || defined(__LITTLE_ENDIAN__) \
1698     || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
1699#    define XXH_CPU_LITTLE_ENDIAN 1
1700#  elif defined(__BIG_ENDIAN__) \
1701     || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
1702#    define XXH_CPU_LITTLE_ENDIAN 0
1703#  else
1704/*!
1705 * @internal
1706 * @brief Runtime check for @ref XXH_CPU_LITTLE_ENDIAN.
1707 *
1708 * Most compilers will constant fold this.
1709 */
1710static int XXH_isLittleEndian(void)
1711{
1712    /*
1713     * Portable and well-defined behavior.
1714     * Don't use static: it is detrimental to performance.
1715     */
1716    const union { xxh_u32 u; xxh_u8 c[4]; } one = { 1 };
1717    return one.c[0];
1718}
1719#   define XXH_CPU_LITTLE_ENDIAN   XXH_isLittleEndian()
1720#  endif
1721#endif
1722
1723
1724
1725
1726/* ****************************************
1727*  Compiler-specific Functions and Macros
1728******************************************/
1729#define XXH_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
1730
1731#ifdef __has_builtin
1732#  define XXH_HAS_BUILTIN(x) __has_builtin(x)
1733#else
1734#  define XXH_HAS_BUILTIN(x) 0
1735#endif
1736
1737/*!
1738 * @internal
1739 * @def XXH_rotl32(x,r)
1740 * @brief 32-bit rotate left.
1741 *
1742 * @param x The 32-bit integer to be rotated.
1743 * @param r The number of bits to rotate.
1744 * @pre
1745 *   @p r > 0 && @p r < 32
1746 * @note
1747 *   @p x and @p r may be evaluated multiple times.
1748 * @return The rotated result.
1749 */
1750#if !defined(NO_CLANG_BUILTIN) && XXH_HAS_BUILTIN(__builtin_rotateleft32) \
1751                               && XXH_HAS_BUILTIN(__builtin_rotateleft64)
1752#  define XXH_rotl32 __builtin_rotateleft32
1753#  define XXH_rotl64 __builtin_rotateleft64
1754/* Note: although _rotl exists for minGW (GCC under windows), performance seems poor */
1755#elif defined(_MSC_VER)
1756#  define XXH_rotl32(x,r) _rotl(x,r)
1757#  define XXH_rotl64(x,r) _rotl64(x,r)
1758#else
1759#  define XXH_rotl32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
1760#  define XXH_rotl64(x,r) (((x) << (r)) | ((x) >> (64 - (r))))
1761#endif
1762
1763/*!
1764 * @internal
1765 * @fn xxh_u32 XXH_swap32(xxh_u32 x)
1766 * @brief A 32-bit byteswap.
1767 *
1768 * @param x The 32-bit integer to byteswap.
1769 * @return @p x, byteswapped.
1770 */
1771#if defined(_MSC_VER)     /* Visual Studio */
1772#  define XXH_swap32 _byteswap_ulong
1773#elif XXH_GCC_VERSION >= 403
1774#  define XXH_swap32 __builtin_bswap32
1775#else
1776static xxh_u32 XXH_swap32 (xxh_u32 x)
1777{
1778    return  ((x << 24) & 0xff000000 ) |
1779            ((x <<  8) & 0x00ff0000 ) |
1780            ((x >>  8) & 0x0000ff00 ) |
1781            ((x >> 24) & 0x000000ff );
1782}
1783#endif
1784
1785
1786/* ***************************
1787*  Memory reads
1788*****************************/
1789
1790/*!
1791 * @internal
1792 * @brief Enum to indicate whether a pointer is aligned.
1793 */
1794typedef enum {
1795    XXH_aligned,  /*!< Aligned */
1796    XXH_unaligned /*!< Possibly unaligned */
1797} XXH_alignment;
1798
1799/*
1800 * XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load.
1801 *
1802 * This is ideal for older compilers which don't inline memcpy.
1803 */
1804#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
1805
1806XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* memPtr)
1807{
1808    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
1809    return bytePtr[0]
1810         | ((xxh_u32)bytePtr[1] << 8)
1811         | ((xxh_u32)bytePtr[2] << 16)
1812         | ((xxh_u32)bytePtr[3] << 24);
1813}
1814
1815XXH_FORCE_INLINE xxh_u32 XXH_readBE32(const void* memPtr)
1816{
1817    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
1818    return bytePtr[3]
1819         | ((xxh_u32)bytePtr[2] << 8)
1820         | ((xxh_u32)bytePtr[1] << 16)
1821         | ((xxh_u32)bytePtr[0] << 24);
1822}
1823
1824#else
1825XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* ptr)
1826{
1827    return XXH_CPU_LITTLE_ENDIAN ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
1828}
1829
1830static xxh_u32 XXH_readBE32(const void* ptr)
1831{
1832    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
1833}
1834#endif
1835
1836XXH_FORCE_INLINE xxh_u32
1837XXH_readLE32_align(const void* ptr, XXH_alignment align)
1838{
1839    if (align==XXH_unaligned) {
1840        return XXH_readLE32(ptr);
1841    } else {
1842        return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u32*)ptr : XXH_swap32(*(const xxh_u32*)ptr);
1843    }
1844}
1845
1846
1847/* *************************************
1848*  Misc
1849***************************************/
1850/*! @ingroup public */
1851XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
1852
1853
1854/* *******************************************************************
1855*  32-bit hash functions
1856*********************************************************************/
1857/*!
1858 * @}
1859 * @defgroup xxh32_impl XXH32 implementation
1860 * @ingroup impl
1861 * @{
1862 */
1863 /* #define instead of static const, to be used as initializers */
1864#define XXH_PRIME32_1  0x9E3779B1U  /*!< 0b10011110001101110111100110110001 */
1865#define XXH_PRIME32_2  0x85EBCA77U  /*!< 0b10000101111010111100101001110111 */
1866#define XXH_PRIME32_3  0xC2B2AE3DU  /*!< 0b11000010101100101010111000111101 */
1867#define XXH_PRIME32_4  0x27D4EB2FU  /*!< 0b00100111110101001110101100101111 */
1868#define XXH_PRIME32_5  0x165667B1U  /*!< 0b00010110010101100110011110110001 */
1869
1870#ifdef XXH_OLD_NAMES
1871#  define PRIME32_1 XXH_PRIME32_1
1872#  define PRIME32_2 XXH_PRIME32_2
1873#  define PRIME32_3 XXH_PRIME32_3
1874#  define PRIME32_4 XXH_PRIME32_4
1875#  define PRIME32_5 XXH_PRIME32_5
1876#endif
1877
1878/*!
1879 * @internal
1880 * @brief Normal stripe processing routine.
1881 *
1882 * This shuffles the bits so that any bit from @p input impacts several bits in
1883 * @p acc.
1884 *
1885 * @param acc The accumulator lane.
1886 * @param input The stripe of input to mix.
1887 * @return The mixed accumulator lane.
1888 */
1889static xxh_u32 XXH32_round(xxh_u32 acc, xxh_u32 input)
1890{
1891    acc += input * XXH_PRIME32_2;
1892    acc  = XXH_rotl32(acc, 13);
1893    acc *= XXH_PRIME32_1;
1894#if (defined(__SSE4_1__) || defined(__aarch64__)) && !defined(XXH_ENABLE_AUTOVECTORIZE)
1895    /*
1896     * UGLY HACK:
1897     * A compiler fence is the only thing that prevents GCC and Clang from
1898     * autovectorizing the XXH32 loop (pragmas and attributes don't work for some
1899     * reason) without globally disabling SSE4.1.
1900     *
1901     * The reason we want to avoid vectorization is because despite working on
1902     * 4 integers at a time, there are multiple factors slowing XXH32 down on
1903     * SSE4:
1904     * - There's a ridiculous amount of lag from pmulld (10 cycles of latency on
1905     *   newer chips!) making it slightly slower to multiply four integers at
1906     *   once compared to four integers independently. Even when pmulld was
1907     *   fastest, Sandy/Ivy Bridge, it is still not worth it to go into SSE
1908     *   just to multiply unless doing a long operation.
1909     *
1910     * - Four instructions are required to rotate,
1911     *      movqda tmp,  v // not required with VEX encoding
1912     *      pslld  tmp, 13 // tmp <<= 13
1913     *      psrld  v,   19 // x >>= 19
1914     *      por    v,  tmp // x |= tmp
1915     *   compared to one for scalar:
1916     *      roll   v, 13    // reliably fast across the board
1917     *      shldl  v, v, 13 // Sandy Bridge and later prefer this for some reason
1918     *
1919     * - Instruction level parallelism is actually more beneficial here because
1920     *   the SIMD actually serializes this operation: While v1 is rotating, v2
1921     *   can load data, while v3 can multiply. SSE forces them to operate
1922     *   together.
1923     *
1924     * This is also enabled on AArch64, as Clang autovectorizes it incorrectly
1925     * and it is pointless writing a NEON implementation that is basically the
1926     * same speed as scalar for XXH32.
1927     */
1928    XXH_COMPILER_GUARD(acc);
1929#endif
1930    return acc;
1931}
1932
1933/*!
1934 * @internal
1935 * @brief Mixes all bits to finalize the hash.
1936 *
1937 * The final mix ensures that all input bits have a chance to impact any bit in
1938 * the output digest, resulting in an unbiased distribution.
1939 *
1940 * @param h32 The hash to avalanche.
1941 * @return The avalanched hash.
1942 */
1943static xxh_u32 XXH32_avalanche(xxh_u32 h32)
1944{
1945    h32 ^= h32 >> 15;
1946    h32 *= XXH_PRIME32_2;
1947    h32 ^= h32 >> 13;
1948    h32 *= XXH_PRIME32_3;
1949    h32 ^= h32 >> 16;
1950    return(h32);
1951}
1952
1953#define XXH_get32bits(p) XXH_readLE32_align(p, align)
1954
1955/*!
1956 * @internal
1957 * @brief Processes the last 0-15 bytes of @p ptr.
1958 *
1959 * There may be up to 15 bytes remaining to consume from the input.
1960 * This final stage will digest them to ensure that all input bytes are present
1961 * in the final mix.
1962 *
1963 * @param h32 The hash to finalize.
1964 * @param ptr The pointer to the remaining input.
1965 * @param len The remaining length, modulo 16.
1966 * @param align Whether @p ptr is aligned.
1967 * @return The finalized hash.
1968 */
1969static xxh_u32
1970XXH32_finalize(xxh_u32 h32, const xxh_u8* ptr, size_t len, XXH_alignment align)
1971{
1972#define XXH_PROCESS1 do {                           \
1973    h32 += (*ptr++) * XXH_PRIME32_5;                \
1974    h32 = XXH_rotl32(h32, 11) * XXH_PRIME32_1;      \
1975} while (0)
1976
1977#define XXH_PROCESS4 do {                           \
1978    h32 += XXH_get32bits(ptr) * XXH_PRIME32_3;      \
1979    ptr += 4;                                   \
1980    h32  = XXH_rotl32(h32, 17) * XXH_PRIME32_4;     \
1981} while (0)
1982
1983    if (ptr==NULL) XXH_ASSERT(len == 0);
1984
1985    /* Compact rerolled version; generally faster */
1986    if (!XXH32_ENDJMP) {
1987        len &= 15;
1988        while (len >= 4) {
1989            XXH_PROCESS4;
1990            len -= 4;
1991        }
1992        while (len > 0) {
1993            XXH_PROCESS1;
1994            --len;
1995        }
1996        return XXH32_avalanche(h32);
1997    } else {
1998         switch(len&15) /* or switch(bEnd - p) */ {
1999           case 12:      XXH_PROCESS4;
2000                         XXH_FALLTHROUGH;
2001           case 8:       XXH_PROCESS4;
2002                         XXH_FALLTHROUGH;
2003           case 4:       XXH_PROCESS4;
2004                         return XXH32_avalanche(h32);
2005
2006           case 13:      XXH_PROCESS4;
2007                         XXH_FALLTHROUGH;
2008           case 9:       XXH_PROCESS4;
2009                         XXH_FALLTHROUGH;
2010           case 5:       XXH_PROCESS4;
2011                         XXH_PROCESS1;
2012                         return XXH32_avalanche(h32);
2013
2014           case 14:      XXH_PROCESS4;
2015                         XXH_FALLTHROUGH;
2016           case 10:      XXH_PROCESS4;
2017                         XXH_FALLTHROUGH;
2018           case 6:       XXH_PROCESS4;
2019                         XXH_PROCESS1;
2020                         XXH_PROCESS1;
2021                         return XXH32_avalanche(h32);
2022
2023           case 15:      XXH_PROCESS4;
2024                         XXH_FALLTHROUGH;
2025           case 11:      XXH_PROCESS4;
2026                         XXH_FALLTHROUGH;
2027           case 7:       XXH_PROCESS4;
2028                         XXH_FALLTHROUGH;
2029           case 3:       XXH_PROCESS1;
2030                         XXH_FALLTHROUGH;
2031           case 2:       XXH_PROCESS1;
2032                         XXH_FALLTHROUGH;
2033           case 1:       XXH_PROCESS1;
2034                         XXH_FALLTHROUGH;
2035           case 0:       return XXH32_avalanche(h32);
2036        }
2037        XXH_ASSERT(0);
2038        return h32;   /* reaching this point is deemed impossible */
2039    }
2040}
2041
2042#ifdef XXH_OLD_NAMES
2043#  define PROCESS1 XXH_PROCESS1
2044#  define PROCESS4 XXH_PROCESS4
2045#else
2046#  undef XXH_PROCESS1
2047#  undef XXH_PROCESS4
2048#endif
2049
2050/*!
2051 * @internal
2052 * @brief The implementation for @ref XXH32().
2053 *
2054 * @param input , len , seed Directly passed from @ref XXH32().
2055 * @param align Whether @p input is aligned.
2056 * @return The calculated hash.
2057 */
2058XXH_FORCE_INLINE xxh_u32
2059XXH32_endian_align(const xxh_u8* input, size_t len, xxh_u32 seed, XXH_alignment align)
2060{
2061    xxh_u32 h32;
2062
2063    if (input==NULL) XXH_ASSERT(len == 0);
2064
2065    if (len>=16) {
2066        const xxh_u8* const bEnd = input + len;
2067        const xxh_u8* const limit = bEnd - 15;
2068        xxh_u32 v1 = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
2069        xxh_u32 v2 = seed + XXH_PRIME32_2;
2070        xxh_u32 v3 = seed + 0;
2071        xxh_u32 v4 = seed - XXH_PRIME32_1;
2072
2073        do {
2074            v1 = XXH32_round(v1, XXH_get32bits(input)); input += 4;
2075            v2 = XXH32_round(v2, XXH_get32bits(input)); input += 4;
2076            v3 = XXH32_round(v3, XXH_get32bits(input)); input += 4;
2077            v4 = XXH32_round(v4, XXH_get32bits(input)); input += 4;
2078        } while (input < limit);
2079
2080        h32 = XXH_rotl32(v1, 1)  + XXH_rotl32(v2, 7)
2081            + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
2082    } else {
2083        h32  = seed + XXH_PRIME32_5;
2084    }
2085
2086    h32 += (xxh_u32)len;
2087
2088    return XXH32_finalize(h32, input, len&15, align);
2089}
2090
2091/*! @ingroup xxh32_family */
2092XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t len, XXH32_hash_t seed)
2093{
2094#if 0
2095    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
2096    XXH32_state_t state;
2097    XXH32_reset(&state, seed);
2098    XXH32_update(&state, (const xxh_u8*)input, len);
2099    return XXH32_digest(&state);
2100#else
2101    if (XXH_FORCE_ALIGN_CHECK) {
2102        if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */
2103            return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
2104    }   }
2105
2106    return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);
2107#endif
2108}
2109
2110
2111
2112/*******   Hash streaming   *******/
2113/*!
2114 * @ingroup xxh32_family
2115 */
2116XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
2117{
2118    return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
2119}
2120/*! @ingroup xxh32_family */
2121XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
2122{
2123    XXH_free(statePtr);
2124    return XXH_OK;
2125}
2126
2127/*! @ingroup xxh32_family */
2128XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dstState, const XXH32_state_t* srcState)
2129{
2130    XXH_memcpy(dstState, srcState, sizeof(*dstState));
2131}
2132
2133/*! @ingroup xxh32_family */
2134XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, XXH32_hash_t seed)
2135{
2136    XXH_ASSERT(statePtr != NULL);
2137    memset(statePtr, 0, sizeof(*statePtr));
2138    statePtr->v[0] = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
2139    statePtr->v[1] = seed + XXH_PRIME32_2;
2140    statePtr->v[2] = seed + 0;
2141    statePtr->v[3] = seed - XXH_PRIME32_1;
2142    return XXH_OK;
2143}
2144
2145
2146/*! @ingroup xxh32_family */
2147XXH_PUBLIC_API XXH_errorcode
2148XXH32_update(XXH32_state_t* state, const void* input, size_t len)
2149{
2150    if (input==NULL) {
2151        XXH_ASSERT(len == 0);
2152        return XXH_OK;
2153    }
2154
2155    {   const xxh_u8* p = (const xxh_u8*)input;
2156        const xxh_u8* const bEnd = p + len;
2157
2158        state->total_len_32 += (XXH32_hash_t)len;
2159        state->large_len |= (XXH32_hash_t)((len>=16) | (state->total_len_32>=16));
2160
2161        if (state->memsize + len < 16)  {   /* fill in tmp buffer */
2162            XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, len);
2163            state->memsize += (XXH32_hash_t)len;
2164            return XXH_OK;
2165        }
2166
2167        if (state->memsize) {   /* some data left from previous update */
2168            XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, 16-state->memsize);
2169            {   const xxh_u32* p32 = state->mem32;
2170                state->v[0] = XXH32_round(state->v[0], XXH_readLE32(p32)); p32++;
2171                state->v[1] = XXH32_round(state->v[1], XXH_readLE32(p32)); p32++;
2172                state->v[2] = XXH32_round(state->v[2], XXH_readLE32(p32)); p32++;
2173                state->v[3] = XXH32_round(state->v[3], XXH_readLE32(p32));
2174            }
2175            p += 16-state->memsize;
2176            state->memsize = 0;
2177        }
2178
2179        if (p <= bEnd-16) {
2180            const xxh_u8* const limit = bEnd - 16;
2181
2182            do {
2183                state->v[0] = XXH32_round(state->v[0], XXH_readLE32(p)); p+=4;
2184                state->v[1] = XXH32_round(state->v[1], XXH_readLE32(p)); p+=4;
2185                state->v[2] = XXH32_round(state->v[2], XXH_readLE32(p)); p+=4;
2186                state->v[3] = XXH32_round(state->v[3], XXH_readLE32(p)); p+=4;
2187            } while (p<=limit);
2188
2189        }
2190
2191        if (p < bEnd) {
2192            XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
2193            state->memsize = (unsigned)(bEnd-p);
2194        }
2195    }
2196
2197    return XXH_OK;
2198}
2199
2200
2201/*! @ingroup xxh32_family */
2202XXH_PUBLIC_API XXH32_hash_t XXH32_digest(const XXH32_state_t* state)
2203{
2204    xxh_u32 h32;
2205
2206    if (state->large_len) {
2207        h32 = XXH_rotl32(state->v[0], 1)
2208            + XXH_rotl32(state->v[1], 7)
2209            + XXH_rotl32(state->v[2], 12)
2210            + XXH_rotl32(state->v[3], 18);
2211    } else {
2212        h32 = state->v[2] /* == seed */ + XXH_PRIME32_5;
2213    }
2214
2215    h32 += state->total_len_32;
2216
2217    return XXH32_finalize(h32, (const xxh_u8*)state->mem32, state->memsize, XXH_aligned);
2218}
2219
2220
2221/*******   Canonical representation   *******/
2222
2223/*!
2224 * @ingroup xxh32_family
2225 * The default return values from XXH functions are unsigned 32 and 64 bit
2226 * integers.
2227 *
2228 * The canonical representation uses big endian convention, the same convention
2229 * as human-readable numbers (large digits first).
2230 *
2231 * This way, hash values can be written into a file or buffer, remaining
2232 * comparable across different systems.
2233 *
2234 * The following functions allow transformation of hash values to and from their
2235 * canonical format.
2236 */
2237XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
2238{
2239    /* XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t)); */
2240    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
2241    XXH_memcpy(dst, &hash, sizeof(*dst));
2242}
2243/*! @ingroup xxh32_family */
2244XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
2245{
2246    return XXH_readBE32(src);
2247}
2248
2249
2250#ifndef XXH_NO_LONG_LONG
2251
2252/* *******************************************************************
2253*  64-bit hash functions
2254*********************************************************************/
2255/*!
2256 * @}
2257 * @ingroup impl
2258 * @{
2259 */
2260/*******   Memory access   *******/
2261
2262typedef XXH64_hash_t xxh_u64;
2263
2264#ifdef XXH_OLD_NAMES
2265#  define U64 xxh_u64
2266#endif
2267
2268#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
2269/*
2270 * Manual byteshift. Best for old compilers which don't inline memcpy.
2271 * We actually directly use XXH_readLE64 and XXH_readBE64.
2272 */
2273#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
2274
2275/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
2276static xxh_u64 XXH_read64(const void* memPtr)
2277{
2278    return *(const xxh_u64*) memPtr;
2279}
2280
2281#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
2282
2283/*
2284 * __pack instructions are safer, but compiler specific, hence potentially
2285 * problematic for some compilers.
2286 *
2287 * Currently only defined for GCC and ICC.
2288 */
2289#ifdef XXH_OLD_NAMES
2290typedef union { xxh_u32 u32; xxh_u64 u64; } __attribute__((packed)) unalign64;
2291#endif
2292static xxh_u64 XXH_read64(const void* ptr)
2293{
2294    typedef union { xxh_u32 u32; xxh_u64 u64; } __attribute__((packed)) xxh_unalign64;
2295    return ((const xxh_unalign64*)ptr)->u64;
2296}
2297
2298#else
2299
2300/*
2301 * Portable and safe solution. Generally efficient.
2302 * see: http://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html
2303 */
2304static xxh_u64 XXH_read64(const void* memPtr)
2305{
2306    xxh_u64 val;
2307    XXH_memcpy(&val, memPtr, sizeof(val));
2308    return val;
2309}
2310
2311#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
2312
2313#if defined(_MSC_VER)     /* Visual Studio */
2314#  define XXH_swap64 _byteswap_uint64
2315#elif XXH_GCC_VERSION >= 403
2316#  define XXH_swap64 __builtin_bswap64
2317#else
2318static xxh_u64 XXH_swap64(xxh_u64 x)
2319{
2320    return  ((x << 56) & 0xff00000000000000ULL) |
2321            ((x << 40) & 0x00ff000000000000ULL) |
2322            ((x << 24) & 0x0000ff0000000000ULL) |
2323            ((x << 8)  & 0x000000ff00000000ULL) |
2324            ((x >> 8)  & 0x00000000ff000000ULL) |
2325            ((x >> 24) & 0x0000000000ff0000ULL) |
2326            ((x >> 40) & 0x000000000000ff00ULL) |
2327            ((x >> 56) & 0x00000000000000ffULL);
2328}
2329#endif
2330
2331
2332/* XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load. */
2333#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
2334
2335XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* memPtr)
2336{
2337    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
2338    return bytePtr[0]
2339         | ((xxh_u64)bytePtr[1] << 8)
2340         | ((xxh_u64)bytePtr[2] << 16)
2341         | ((xxh_u64)bytePtr[3] << 24)
2342         | ((xxh_u64)bytePtr[4] << 32)
2343         | ((xxh_u64)bytePtr[5] << 40)
2344         | ((xxh_u64)bytePtr[6] << 48)
2345         | ((xxh_u64)bytePtr[7] << 56);
2346}
2347
2348XXH_FORCE_INLINE xxh_u64 XXH_readBE64(const void* memPtr)
2349{
2350    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
2351    return bytePtr[7]
2352         | ((xxh_u64)bytePtr[6] << 8)
2353         | ((xxh_u64)bytePtr[5] << 16)
2354         | ((xxh_u64)bytePtr[4] << 24)
2355         | ((xxh_u64)bytePtr[3] << 32)
2356         | ((xxh_u64)bytePtr[2] << 40)
2357         | ((xxh_u64)bytePtr[1] << 48)
2358         | ((xxh_u64)bytePtr[0] << 56);
2359}
2360
2361#else
2362XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* ptr)
2363{
2364    return XXH_CPU_LITTLE_ENDIAN ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
2365}
2366
2367static xxh_u64 XXH_readBE64(const void* ptr)
2368{
2369    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
2370}
2371#endif
2372
2373XXH_FORCE_INLINE xxh_u64
2374XXH_readLE64_align(const void* ptr, XXH_alignment align)
2375{
2376    if (align==XXH_unaligned)
2377        return XXH_readLE64(ptr);
2378    else
2379        return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u64*)ptr : XXH_swap64(*(const xxh_u64*)ptr);
2380}
2381
2382
2383/*******   xxh64   *******/
2384/*!
2385 * @}
2386 * @defgroup xxh64_impl XXH64 implementation
2387 * @ingroup impl
2388 * @{
2389 */
2390/* #define rather that static const, to be used as initializers */
2391#define XXH_PRIME64_1  0x9E3779B185EBCA87ULL  /*!< 0b1001111000110111011110011011000110000101111010111100101010000111 */
2392#define XXH_PRIME64_2  0xC2B2AE3D27D4EB4FULL  /*!< 0b1100001010110010101011100011110100100111110101001110101101001111 */
2393#define XXH_PRIME64_3  0x165667B19E3779F9ULL  /*!< 0b0001011001010110011001111011000110011110001101110111100111111001 */
2394#define XXH_PRIME64_4  0x85EBCA77C2B2AE63ULL  /*!< 0b1000010111101011110010100111011111000010101100101010111001100011 */
2395#define XXH_PRIME64_5  0x27D4EB2F165667C5ULL  /*!< 0b0010011111010100111010110010111100010110010101100110011111000101 */
2396
2397#ifdef XXH_OLD_NAMES
2398#  define PRIME64_1 XXH_PRIME64_1
2399#  define PRIME64_2 XXH_PRIME64_2
2400#  define PRIME64_3 XXH_PRIME64_3
2401#  define PRIME64_4 XXH_PRIME64_4
2402#  define PRIME64_5 XXH_PRIME64_5
2403#endif
2404
2405static xxh_u64 XXH64_round(xxh_u64 acc, xxh_u64 input)
2406{
2407    acc += input * XXH_PRIME64_2;
2408    acc  = XXH_rotl64(acc, 31);
2409    acc *= XXH_PRIME64_1;
2410    return acc;
2411}
2412
2413static xxh_u64 XXH64_mergeRound(xxh_u64 acc, xxh_u64 val)
2414{
2415    val  = XXH64_round(0, val);
2416    acc ^= val;
2417    acc  = acc * XXH_PRIME64_1 + XXH_PRIME64_4;
2418    return acc;
2419}
2420
2421static xxh_u64 XXH64_avalanche(xxh_u64 h64)
2422{
2423    h64 ^= h64 >> 33;
2424    h64 *= XXH_PRIME64_2;
2425    h64 ^= h64 >> 29;
2426    h64 *= XXH_PRIME64_3;
2427    h64 ^= h64 >> 32;
2428    return h64;
2429}
2430
2431
2432#define XXH_get64bits(p) XXH_readLE64_align(p, align)
2433
2434static xxh_u64
2435XXH64_finalize(xxh_u64 h64, const xxh_u8* ptr, size_t len, XXH_alignment align)
2436{
2437    if (ptr==NULL) XXH_ASSERT(len == 0);
2438    len &= 31;
2439    while (len >= 8) {
2440        xxh_u64 const k1 = XXH64_round(0, XXH_get64bits(ptr));
2441        ptr += 8;
2442        h64 ^= k1;
2443        h64  = XXH_rotl64(h64,27) * XXH_PRIME64_1 + XXH_PRIME64_4;
2444        len -= 8;
2445    }
2446    if (len >= 4) {
2447        h64 ^= (xxh_u64)(XXH_get32bits(ptr)) * XXH_PRIME64_1;
2448        ptr += 4;
2449        h64 = XXH_rotl64(h64, 23) * XXH_PRIME64_2 + XXH_PRIME64_3;
2450        len -= 4;
2451    }
2452    while (len > 0) {
2453        h64 ^= (*ptr++) * XXH_PRIME64_5;
2454        h64 = XXH_rotl64(h64, 11) * XXH_PRIME64_1;
2455        --len;
2456    }
2457    return  XXH64_avalanche(h64);
2458}
2459
2460#ifdef XXH_OLD_NAMES
2461#  define PROCESS1_64 XXH_PROCESS1_64
2462#  define PROCESS4_64 XXH_PROCESS4_64
2463#  define PROCESS8_64 XXH_PROCESS8_64
2464#else
2465#  undef XXH_PROCESS1_64
2466#  undef XXH_PROCESS4_64
2467#  undef XXH_PROCESS8_64
2468#endif
2469
2470XXH_FORCE_INLINE xxh_u64
2471XXH64_endian_align(const xxh_u8* input, size_t len, xxh_u64 seed, XXH_alignment align)
2472{
2473    xxh_u64 h64;
2474    if (input==NULL) XXH_ASSERT(len == 0);
2475
2476    if (len>=32) {
2477        const xxh_u8* const bEnd = input + len;
2478        const xxh_u8* const limit = bEnd - 31;
2479        xxh_u64 v1 = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
2480        xxh_u64 v2 = seed + XXH_PRIME64_2;
2481        xxh_u64 v3 = seed + 0;
2482        xxh_u64 v4 = seed - XXH_PRIME64_1;
2483
2484        do {
2485            v1 = XXH64_round(v1, XXH_get64bits(input)); input+=8;
2486            v2 = XXH64_round(v2, XXH_get64bits(input)); input+=8;
2487            v3 = XXH64_round(v3, XXH_get64bits(input)); input+=8;
2488            v4 = XXH64_round(v4, XXH_get64bits(input)); input+=8;
2489        } while (input<limit);
2490
2491        h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
2492        h64 = XXH64_mergeRound(h64, v1);
2493        h64 = XXH64_mergeRound(h64, v2);
2494        h64 = XXH64_mergeRound(h64, v3);
2495        h64 = XXH64_mergeRound(h64, v4);
2496
2497    } else {
2498        h64  = seed + XXH_PRIME64_5;
2499    }
2500
2501    h64 += (xxh_u64) len;
2502
2503    return XXH64_finalize(h64, input, len, align);
2504}
2505
2506
2507/*! @ingroup xxh64_family */
2508XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t len, XXH64_hash_t seed)
2509{
2510#if 0
2511    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
2512    XXH64_state_t state;
2513    XXH64_reset(&state, seed);
2514    XXH64_update(&state, (const xxh_u8*)input, len);
2515    return XXH64_digest(&state);
2516#else
2517    if (XXH_FORCE_ALIGN_CHECK) {
2518        if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */
2519            return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
2520    }   }
2521
2522    return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);
2523
2524#endif
2525}
2526
2527/*******   Hash Streaming   *******/
2528
2529/*! @ingroup xxh64_family*/
2530XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
2531{
2532    return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
2533}
2534/*! @ingroup xxh64_family */
2535XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
2536{
2537    XXH_free(statePtr);
2538    return XXH_OK;
2539}
2540
2541/*! @ingroup xxh64_family */
2542XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* dstState, const XXH64_state_t* srcState)
2543{
2544    XXH_memcpy(dstState, srcState, sizeof(*dstState));
2545}
2546
2547/*! @ingroup xxh64_family */
2548XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, XXH64_hash_t seed)
2549{
2550    XXH_ASSERT(statePtr != NULL);
2551    memset(statePtr, 0, sizeof(*statePtr));
2552    statePtr->v[0] = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
2553    statePtr->v[1] = seed + XXH_PRIME64_2;
2554    statePtr->v[2] = seed + 0;
2555    statePtr->v[3] = seed - XXH_PRIME64_1;
2556    return XXH_OK;
2557}
2558
2559/*! @ingroup xxh64_family */
2560XXH_PUBLIC_API XXH_errorcode
2561XXH64_update (XXH64_state_t* state, const void* input, size_t len)
2562{
2563    if (input==NULL) {
2564        XXH_ASSERT(len == 0);
2565        return XXH_OK;
2566    }
2567
2568    {   const xxh_u8* p = (const xxh_u8*)input;
2569        const xxh_u8* const bEnd = p + len;
2570
2571        state->total_len += len;
2572
2573        if (state->memsize + len < 32) {  /* fill in tmp buffer */
2574            XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, len);
2575            state->memsize += (xxh_u32)len;
2576            return XXH_OK;
2577        }
2578
2579        if (state->memsize) {   /* tmp buffer is full */
2580            XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, 32-state->memsize);
2581            state->v[0] = XXH64_round(state->v[0], XXH_readLE64(state->mem64+0));
2582            state->v[1] = XXH64_round(state->v[1], XXH_readLE64(state->mem64+1));
2583            state->v[2] = XXH64_round(state->v[2], XXH_readLE64(state->mem64+2));
2584            state->v[3] = XXH64_round(state->v[3], XXH_readLE64(state->mem64+3));
2585            p += 32 - state->memsize;
2586            state->memsize = 0;
2587        }
2588
2589        if (p+32 <= bEnd) {
2590            const xxh_u8* const limit = bEnd - 32;
2591
2592            do {
2593                state->v[0] = XXH64_round(state->v[0], XXH_readLE64(p)); p+=8;
2594                state->v[1] = XXH64_round(state->v[1], XXH_readLE64(p)); p+=8;
2595                state->v[2] = XXH64_round(state->v[2], XXH_readLE64(p)); p+=8;
2596                state->v[3] = XXH64_round(state->v[3], XXH_readLE64(p)); p+=8;
2597            } while (p<=limit);
2598
2599        }
2600
2601        if (p < bEnd) {
2602            XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
2603            state->memsize = (unsigned)(bEnd-p);
2604        }
2605    }
2606
2607    return XXH_OK;
2608}
2609
2610
2611/*! @ingroup xxh64_family */
2612XXH_PUBLIC_API XXH64_hash_t XXH64_digest(const XXH64_state_t* state)
2613{
2614    xxh_u64 h64;
2615
2616    if (state->total_len >= 32) {
2617        h64 = XXH_rotl64(state->v[0], 1) + XXH_rotl64(state->v[1], 7) + XXH_rotl64(state->v[2], 12) + XXH_rotl64(state->v[3], 18);
2618        h64 = XXH64_mergeRound(h64, state->v[0]);
2619        h64 = XXH64_mergeRound(h64, state->v[1]);
2620        h64 = XXH64_mergeRound(h64, state->v[2]);
2621        h64 = XXH64_mergeRound(h64, state->v[3]);
2622    } else {
2623        h64  = state->v[2] /*seed*/ + XXH_PRIME64_5;
2624    }
2625
2626    h64 += (xxh_u64) state->total_len;
2627
2628    return XXH64_finalize(h64, (const xxh_u8*)state->mem64, (size_t)state->total_len, XXH_aligned);
2629}
2630
2631
2632/******* Canonical representation   *******/
2633
2634/*! @ingroup xxh64_family */
2635XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
2636{
2637    /* XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t)); */
2638    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
2639    XXH_memcpy(dst, &hash, sizeof(*dst));
2640}
2641
2642/*! @ingroup xxh64_family */
2643XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
2644{
2645    return XXH_readBE64(src);
2646}
2647
2648#ifndef XXH_NO_XXH3
2649
2650/* *********************************************************************
2651*  XXH3
2652*  New generation hash designed for speed on small keys and vectorization
2653************************************************************************ */
2654/*!
2655 * @}
2656 * @defgroup xxh3_impl XXH3 implementation
2657 * @ingroup impl
2658 * @{
2659 */
2660
2661/* ===   Compiler specifics   === */
2662
2663#if ((defined(sun) || defined(__sun)) && __cplusplus) /* Solaris includes __STDC_VERSION__ with C++. Tested with GCC 5.5 */
2664#  define XXH_RESTRICT /* disable */
2665#elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* >= C99 */
2666#  define XXH_RESTRICT   restrict
2667#else
2668/* Note: it might be useful to define __restrict or __restrict__ for some C++ compilers */
2669#  define XXH_RESTRICT   /* disable */
2670#endif
2671
2672#if (defined(__GNUC__) && (__GNUC__ >= 3))  \
2673  || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) \
2674  || defined(__clang__)
2675#    define XXH_likely(x) __builtin_expect(x, 1)
2676#    define XXH_unlikely(x) __builtin_expect(x, 0)
2677#else
2678#    define XXH_likely(x) (x)
2679#    define XXH_unlikely(x) (x)
2680#endif
2681
2682#if defined(__GNUC__) || defined(__clang__)
2683#  if defined(__ARM_NEON__) || defined(__ARM_NEON) \
2684   || defined(__aarch64__)  || defined(_M_ARM) \
2685   || defined(_M_ARM64)     || defined(_M_ARM64EC)
2686#    define inline __inline__  /* circumvent a clang bug */
2687#    include <arm_neon.h>
2688#    undef inline
2689#  elif defined(__AVX2__)
2690#    include <immintrin.h>
2691#  elif defined(__SSE2__)
2692#    include <emmintrin.h>
2693#  endif
2694#endif
2695
2696#if defined(_MSC_VER)
2697#  include <intrin.h>
2698#endif
2699
2700/*
2701 * One goal of XXH3 is to make it fast on both 32-bit and 64-bit, while
2702 * remaining a true 64-bit/128-bit hash function.
2703 *
2704 * This is done by prioritizing a subset of 64-bit operations that can be
2705 * emulated without too many steps on the average 32-bit machine.
2706 *
2707 * For example, these two lines seem similar, and run equally fast on 64-bit:
2708 *
2709 *   xxh_u64 x;
2710 *   x ^= (x >> 47); // good
2711 *   x ^= (x >> 13); // bad
2712 *
2713 * However, to a 32-bit machine, there is a major difference.
2714 *
2715 * x ^= (x >> 47) looks like this:
2716 *
2717 *   x.lo ^= (x.hi >> (47 - 32));
2718 *
2719 * while x ^= (x >> 13) looks like this:
2720 *
2721 *   // note: funnel shifts are not usually cheap.
2722 *   x.lo ^= (x.lo >> 13) | (x.hi << (32 - 13));
2723 *   x.hi ^= (x.hi >> 13);
2724 *
2725 * The first one is significantly faster than the second, simply because the
2726 * shift is larger than 32. This means:
2727 *  - All the bits we need are in the upper 32 bits, so we can ignore the lower
2728 *    32 bits in the shift.
2729 *  - The shift result will always fit in the lower 32 bits, and therefore,
2730 *    we can ignore the upper 32 bits in the xor.
2731 *
2732 * Thanks to this optimization, XXH3 only requires these features to be efficient:
2733 *
2734 *  - Usable unaligned access
2735 *  - A 32-bit or 64-bit ALU
2736 *      - If 32-bit, a decent ADC instruction
2737 *  - A 32 or 64-bit multiply with a 64-bit result
2738 *  - For the 128-bit variant, a decent byteswap helps short inputs.
2739 *
2740 * The first two are already required by XXH32, and almost all 32-bit and 64-bit
2741 * platforms which can run XXH32 can run XXH3 efficiently.
2742 *
2743 * Thumb-1, the classic 16-bit only subset of ARM's instruction set, is one
2744 * notable exception.
2745 *
2746 * First of all, Thumb-1 lacks support for the UMULL instruction which
2747 * performs the important long multiply. This means numerous __aeabi_lmul
2748 * calls.
2749 *
2750 * Second of all, the 8 functional registers are just not enough.
2751 * Setup for __aeabi_lmul, byteshift loads, pointers, and all arithmetic need
2752 * Lo registers, and this shuffling results in thousands more MOVs than A32.
2753 *
2754 * A32 and T32 don't have this limitation. They can access all 14 registers,
2755 * do a 32->64 multiply with UMULL, and the flexible operand allowing free
2756 * shifts is helpful, too.
2757 *
2758 * Therefore, we do a quick sanity check.
2759 *
2760 * If compiling Thumb-1 for a target which supports ARM instructions, we will
2761 * emit a warning, as it is not a "sane" platform to compile for.
2762 *
2763 * Usually, if this happens, it is because of an accident and you probably need
2764 * to specify -march, as you likely meant to compile for a newer architecture.
2765 *
2766 * Credit: large sections of the vectorial and asm source code paths
2767 *         have been contributed by @easyaspi314
2768 */
2769#if defined(__thumb__) && !defined(__thumb2__) && defined(__ARM_ARCH_ISA_ARM)
2770#   warning "XXH3 is highly inefficient without ARM or Thumb-2."
2771#endif
2772
2773/* ==========================================
2774 * Vectorization detection
2775 * ========================================== */
2776
2777#ifdef XXH_DOXYGEN
2778/*!
2779 * @ingroup tuning
2780 * @brief Overrides the vectorization implementation chosen for XXH3.
2781 *
2782 * Can be defined to 0 to disable SIMD or any of the values mentioned in
2783 * @ref XXH_VECTOR_TYPE.
2784 *
2785 * If this is not defined, it uses predefined macros to determine the best
2786 * implementation.
2787 */
2788#  define XXH_VECTOR XXH_SCALAR
2789/*!
2790 * @ingroup tuning
2791 * @brief Possible values for @ref XXH_VECTOR.
2792 *
2793 * Note that these are actually implemented as macros.
2794 *
2795 * If this is not defined, it is detected automatically.
2796 * @ref XXH_X86DISPATCH overrides this.
2797 */
2798enum XXH_VECTOR_TYPE /* fake enum */ {
2799    XXH_SCALAR = 0,  /*!< Portable scalar version */
2800    XXH_SSE2   = 1,  /*!<
2801                      * SSE2 for Pentium 4, Opteron, all x86_64.
2802                      *
2803                      * @note SSE2 is also guaranteed on Windows 10, macOS, and
2804                      * Android x86.
2805                      */
2806    XXH_AVX2   = 2,  /*!< AVX2 for Haswell and Bulldozer */
2807    XXH_AVX512 = 3,  /*!< AVX512 for Skylake and Icelake */
2808    XXH_NEON   = 4,  /*!< NEON for most ARMv7-A and all AArch64 */
2809    XXH_VSX    = 5,  /*!< VSX and ZVector for POWER8/z13 (64-bit) */
2810};
2811/*!
2812 * @ingroup tuning
2813 * @brief Selects the minimum alignment for XXH3's accumulators.
2814 *
2815 * When using SIMD, this should match the alignment reqired for said vector
2816 * type, so, for example, 32 for AVX2.
2817 *
2818 * Default: Auto detected.
2819 */
2820#  define XXH_ACC_ALIGN 8
2821#endif
2822
2823/* Actual definition */
2824#ifndef XXH_DOXYGEN
2825#  define XXH_SCALAR 0
2826#  define XXH_SSE2   1
2827#  define XXH_AVX2   2
2828#  define XXH_AVX512 3
2829#  define XXH_NEON   4
2830#  define XXH_VSX    5
2831#endif
2832
2833#ifndef XXH_VECTOR    /* can be defined on command line */
2834#  if ( \
2835        defined(__ARM_NEON__) || defined(__ARM_NEON) /* gcc */ \
2836     || defined(_M_ARM) || defined(_M_ARM64) || defined(_M_ARM64EC) /* msvc */ \
2837   ) && ( \
2838        defined(_WIN32) || defined(__LITTLE_ENDIAN__) /* little endian only */ \
2839    || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) \
2840   )
2841#    define XXH_VECTOR XXH_NEON
2842#  elif defined(__AVX512F__)
2843#    define XXH_VECTOR XXH_AVX512
2844#  elif defined(__AVX2__)
2845#    define XXH_VECTOR XXH_AVX2
2846#  elif defined(__SSE2__) || defined(_M_AMD64) || defined(_M_X64) || (defined(_M_IX86_FP) && (_M_IX86_FP == 2))
2847#    define XXH_VECTOR XXH_SSE2
2848#  elif (defined(__PPC64__) && defined(__POWER8_VECTOR__)) \
2849     || (defined(__s390x__) && defined(__VEC__)) \
2850     && defined(__GNUC__) /* TODO: IBM XL */
2851#    define XXH_VECTOR XXH_VSX
2852#  else
2853#    define XXH_VECTOR XXH_SCALAR
2854#  endif
2855#endif
2856
2857/*
2858 * Controls the alignment of the accumulator,
2859 * for compatibility with aligned vector loads, which are usually faster.
2860 */
2861#ifndef XXH_ACC_ALIGN
2862#  if defined(XXH_X86DISPATCH)
2863#     define XXH_ACC_ALIGN 64  /* for compatibility with avx512 */
2864#  elif XXH_VECTOR == XXH_SCALAR  /* scalar */
2865#     define XXH_ACC_ALIGN 8
2866#  elif XXH_VECTOR == XXH_SSE2  /* sse2 */
2867#     define XXH_ACC_ALIGN 16
2868#  elif XXH_VECTOR == XXH_AVX2  /* avx2 */
2869#     define XXH_ACC_ALIGN 32
2870#  elif XXH_VECTOR == XXH_NEON  /* neon */
2871#     define XXH_ACC_ALIGN 16
2872#  elif XXH_VECTOR == XXH_VSX   /* vsx */
2873#     define XXH_ACC_ALIGN 16
2874#  elif XXH_VECTOR == XXH_AVX512  /* avx512 */
2875#     define XXH_ACC_ALIGN 64
2876#  endif
2877#endif
2878
2879#if defined(XXH_X86DISPATCH) || XXH_VECTOR == XXH_SSE2 \
2880    || XXH_VECTOR == XXH_AVX2 || XXH_VECTOR == XXH_AVX512
2881#  define XXH_SEC_ALIGN XXH_ACC_ALIGN
2882#else
2883#  define XXH_SEC_ALIGN 8
2884#endif
2885
2886/*
2887 * UGLY HACK:
2888 * GCC usually generates the best code with -O3 for xxHash.
2889 *
2890 * However, when targeting AVX2, it is overzealous in its unrolling resulting
2891 * in code roughly 3/4 the speed of Clang.
2892 *
2893 * There are other issues, such as GCC splitting _mm256_loadu_si256 into
2894 * _mm_loadu_si128 + _mm256_inserti128_si256. This is an optimization which
2895 * only applies to Sandy and Ivy Bridge... which don't even support AVX2.
2896 *
2897 * That is why when compiling the AVX2 version, it is recommended to use either
2898 *   -O2 -mavx2 -march=haswell
2899 * or
2900 *   -O2 -mavx2 -mno-avx256-split-unaligned-load
2901 * for decent performance, or to use Clang instead.
2902 *
2903 * Fortunately, we can control the first one with a pragma that forces GCC into
2904 * -O2, but the other one we can't control without "failed to inline always
2905 * inline function due to target mismatch" warnings.
2906 */
2907#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
2908  && defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
2909  && defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
2910#  pragma GCC push_options
2911#  pragma GCC optimize("-O2")
2912#endif
2913
2914
2915#if XXH_VECTOR == XXH_NEON
2916/*
2917 * NEON's setup for vmlal_u32 is a little more complicated than it is on
2918 * SSE2, AVX2, and VSX.
2919 *
2920 * While PMULUDQ and VMULEUW both perform a mask, VMLAL.U32 performs an upcast.
2921 *
2922 * To do the same operation, the 128-bit 'Q' register needs to be split into
2923 * two 64-bit 'D' registers, performing this operation::
2924 *
2925 *   [                a                 |                 b                ]
2926 *            |              '---------. .--------'                |
2927 *            |                         x                          |
2928 *            |              .---------' '--------.                |
2929 *   [ a & 0xFFFFFFFF | b & 0xFFFFFFFF ],[    a >> 32     |     b >> 32    ]
2930 *
2931 * Due to significant changes in aarch64, the fastest method for aarch64 is
2932 * completely different than the fastest method for ARMv7-A.
2933 *
2934 * ARMv7-A treats D registers as unions overlaying Q registers, so modifying
2935 * D11 will modify the high half of Q5. This is similar to how modifying AH
2936 * will only affect bits 8-15 of AX on x86.
2937 *
2938 * VZIP takes two registers, and puts even lanes in one register and odd lanes
2939 * in the other.
2940 *
2941 * On ARMv7-A, this strangely modifies both parameters in place instead of
2942 * taking the usual 3-operand form.
2943 *
2944 * Therefore, if we want to do this, we can simply use a D-form VZIP.32 on the
2945 * lower and upper halves of the Q register to end up with the high and low
2946 * halves where we want - all in one instruction.
2947 *
2948 *   vzip.32   d10, d11       @ d10 = { d10[0], d11[0] }; d11 = { d10[1], d11[1] }
2949 *
2950 * Unfortunately we need inline assembly for this: Instructions modifying two
2951 * registers at once is not possible in GCC or Clang's IR, and they have to
2952 * create a copy.
2953 *
2954 * aarch64 requires a different approach.
2955 *
2956 * In order to make it easier to write a decent compiler for aarch64, many
2957 * quirks were removed, such as conditional execution.
2958 *
2959 * NEON was also affected by this.
2960 *
2961 * aarch64 cannot access the high bits of a Q-form register, and writes to a
2962 * D-form register zero the high bits, similar to how writes to W-form scalar
2963 * registers (or DWORD registers on x86_64) work.
2964 *
2965 * The formerly free vget_high intrinsics now require a vext (with a few
2966 * exceptions)
2967 *
2968 * Additionally, VZIP was replaced by ZIP1 and ZIP2, which are the equivalent
2969 * of PUNPCKL* and PUNPCKH* in SSE, respectively, in order to only modify one
2970 * operand.
2971 *
2972 * The equivalent of the VZIP.32 on the lower and upper halves would be this
2973 * mess:
2974 *
2975 *   ext     v2.4s, v0.4s, v0.4s, #2 // v2 = { v0[2], v0[3], v0[0], v0[1] }
2976 *   zip1    v1.2s, v0.2s, v2.2s     // v1 = { v0[0], v2[0] }
2977 *   zip2    v0.2s, v0.2s, v1.2s     // v0 = { v0[1], v2[1] }
2978 *
2979 * Instead, we use a literal downcast, vmovn_u64 (XTN), and vshrn_n_u64 (SHRN):
2980 *
2981 *   shrn    v1.2s, v0.2d, #32  // v1 = (uint32x2_t)(v0 >> 32);
2982 *   xtn     v0.2s, v0.2d       // v0 = (uint32x2_t)(v0 & 0xFFFFFFFF);
2983 *
2984 * This is available on ARMv7-A, but is less efficient than a single VZIP.32.
2985 */
2986
2987/*!
2988 * Function-like macro:
2989 * void XXH_SPLIT_IN_PLACE(uint64x2_t &in, uint32x2_t &outLo, uint32x2_t &outHi)
2990 * {
2991 *     outLo = (uint32x2_t)(in & 0xFFFFFFFF);
2992 *     outHi = (uint32x2_t)(in >> 32);
2993 *     in = UNDEFINED;
2994 * }
2995 */
2996# if !defined(XXH_NO_VZIP_HACK) /* define to disable */ \
2997   && (defined(__GNUC__) || defined(__clang__)) \
2998   && (defined(__arm__) || defined(__thumb__) || defined(_M_ARM))
2999#  define XXH_SPLIT_IN_PLACE(in, outLo, outHi)                                              \
3000    do {                                                                                    \
3001      /* Undocumented GCC/Clang operand modifier: %e0 = lower D half, %f0 = upper D half */ \
3002      /* https://github.com/gcc-mirror/gcc/blob/38cf91e5/gcc/config/arm/arm.c#L22486 */     \
3003      /* https://github.com/llvm-mirror/llvm/blob/2c4ca683/lib/Target/ARM/ARMAsmPrinter.cpp#L399 */ \
3004      __asm__("vzip.32  %e0, %f0" : "+w" (in));                                             \
3005      (outLo) = vget_low_u32 (vreinterpretq_u32_u64(in));                                   \
3006      (outHi) = vget_high_u32(vreinterpretq_u32_u64(in));                                   \
3007   } while (0)
3008# else
3009#  define XXH_SPLIT_IN_PLACE(in, outLo, outHi)                                            \
3010    do {                                                                                  \
3011      (outLo) = vmovn_u64    (in);                                                        \
3012      (outHi) = vshrn_n_u64  ((in), 32);                                                  \
3013    } while (0)
3014# endif
3015
3016/*!
3017 * @ingroup tuning
3018 * @brief Controls the NEON to scalar ratio for XXH3
3019 *
3020 * On AArch64 when not optimizing for size, XXH3 will run 6 lanes using NEON and
3021 * 2 lanes on scalar by default.
3022 *
3023 * This can be set to 2, 4, 6, or 8. ARMv7 will default to all 8 NEON lanes, as the
3024 * emulated 64-bit arithmetic is too slow.
3025 *
3026 * Modern ARM CPUs are _very_ sensitive to how their pipelines are used.
3027 *
3028 * For example, the Cortex-A73 can dispatch 3 micro-ops per cycle, but it can't
3029 * have more than 2 NEON (F0/F1) micro-ops. If you are only using NEON instructions,
3030 * you are only using 2/3 of the CPU bandwidth.
3031 *
3032 * This is even more noticable on the more advanced cores like the A76 which
3033 * can dispatch 8 micro-ops per cycle, but still only 2 NEON micro-ops at once.
3034 *
3035 * Therefore, @ref XXH3_NEON_LANES lanes will be processed using NEON, and the
3036 * remaining lanes will use scalar instructions. This improves the bandwidth
3037 * and also gives the integer pipelines something to do besides twiddling loop
3038 * counters and pointers.
3039 *
3040 * This change benefits CPUs with large micro-op buffers without negatively affecting
3041 * other CPUs:
3042 *
3043 *  | Chipset               | Dispatch type       | NEON only | 6:2 hybrid | Diff. |
3044 *  |:----------------------|:--------------------|----------:|-----------:|------:|
3045 *  | Snapdragon 730 (A76)  | 2 NEON/8 micro-ops  |  8.8 GB/s |  10.1 GB/s |  ~16% |
3046 *  | Snapdragon 835 (A73)  | 2 NEON/3 micro-ops  |  5.1 GB/s |   5.3 GB/s |   ~5% |
3047 *  | Marvell PXA1928 (A53) | In-order dual-issue |  1.9 GB/s |   1.9 GB/s |    0% |
3048 *
3049 * It also seems to fix some bad codegen on GCC, making it almost as fast as clang.
3050 *
3051 * @see XXH3_accumulate_512_neon()
3052 */
3053# ifndef XXH3_NEON_LANES
3054#  if (defined(__aarch64__) || defined(__arm64__) || defined(_M_ARM64) || defined(_M_ARM64EC)) \
3055   && !defined(__OPTIMIZE_SIZE__)
3056#   define XXH3_NEON_LANES 6
3057#  else
3058#   define XXH3_NEON_LANES XXH_ACC_NB
3059#  endif
3060# endif
3061#endif  /* XXH_VECTOR == XXH_NEON */
3062
3063/*
3064 * VSX and Z Vector helpers.
3065 *
3066 * This is very messy, and any pull requests to clean this up are welcome.
3067 *
3068 * There are a lot of problems with supporting VSX and s390x, due to
3069 * inconsistent intrinsics, spotty coverage, and multiple endiannesses.
3070 */
3071#if XXH_VECTOR == XXH_VSX
3072#  if defined(__s390x__)
3073#    include <s390intrin.h>
3074#  else
3075/* gcc's altivec.h can have the unwanted consequence to unconditionally
3076 * #define bool, vector, and pixel keywords,
3077 * with bad consequences for programs already using these keywords for other purposes.
3078 * The paragraph defining these macros is skipped when __APPLE_ALTIVEC__ is defined.
3079 * __APPLE_ALTIVEC__ is _generally_ defined automatically by the compiler,
3080 * but it seems that, in some cases, it isn't.
3081 * Force the build macro to be defined, so that keywords are not altered.
3082 */
3083#    if defined(__GNUC__) && !defined(__APPLE_ALTIVEC__)
3084#      define __APPLE_ALTIVEC__
3085#    endif
3086#    include <altivec.h>
3087#  endif
3088
3089typedef __vector unsigned long long xxh_u64x2;
3090typedef __vector unsigned char xxh_u8x16;
3091typedef __vector unsigned xxh_u32x4;
3092
3093# ifndef XXH_VSX_BE
3094#  if defined(__BIG_ENDIAN__) \
3095  || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
3096#    define XXH_VSX_BE 1
3097#  elif defined(__VEC_ELEMENT_REG_ORDER__) && __VEC_ELEMENT_REG_ORDER__ == __ORDER_BIG_ENDIAN__
3098#    warning "-maltivec=be is not recommended. Please use native endianness."
3099#    define XXH_VSX_BE 1
3100#  else
3101#    define XXH_VSX_BE 0
3102#  endif
3103# endif /* !defined(XXH_VSX_BE) */
3104
3105# if XXH_VSX_BE
3106#  if defined(__POWER9_VECTOR__) || (defined(__clang__) && defined(__s390x__))
3107#    define XXH_vec_revb vec_revb
3108#  else
3109/*!
3110 * A polyfill for POWER9's vec_revb().
3111 */
3112XXH_FORCE_INLINE xxh_u64x2 XXH_vec_revb(xxh_u64x2 val)
3113{
3114    xxh_u8x16 const vByteSwap = { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
3115                                  0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08 };
3116    return vec_perm(val, val, vByteSwap);
3117}
3118#  endif
3119# endif /* XXH_VSX_BE */
3120
3121/*!
3122 * Performs an unaligned vector load and byte swaps it on big endian.
3123 */
3124XXH_FORCE_INLINE xxh_u64x2 XXH_vec_loadu(const void *ptr)
3125{
3126    xxh_u64x2 ret;
3127    XXH_memcpy(&ret, ptr, sizeof(xxh_u64x2));
3128# if XXH_VSX_BE
3129    ret = XXH_vec_revb(ret);
3130# endif
3131    return ret;
3132}
3133
3134/*
3135 * vec_mulo and vec_mule are very problematic intrinsics on PowerPC
3136 *
3137 * These intrinsics weren't added until GCC 8, despite existing for a while,
3138 * and they are endian dependent. Also, their meaning swap depending on version.
3139 * */
3140# if defined(__s390x__)
3141 /* s390x is always big endian, no issue on this platform */
3142#  define XXH_vec_mulo vec_mulo
3143#  define XXH_vec_mule vec_mule
3144# elif defined(__clang__) && XXH_HAS_BUILTIN(__builtin_altivec_vmuleuw)
3145/* Clang has a better way to control this, we can just use the builtin which doesn't swap. */
3146#  define XXH_vec_mulo __builtin_altivec_vmulouw
3147#  define XXH_vec_mule __builtin_altivec_vmuleuw
3148# else
3149/* gcc needs inline assembly */
3150/* Adapted from https://github.com/google/highwayhash/blob/master/highwayhash/hh_vsx.h. */
3151XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mulo(xxh_u32x4 a, xxh_u32x4 b)
3152{
3153    xxh_u64x2 result;
3154    __asm__("vmulouw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
3155    return result;
3156}
3157XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mule(xxh_u32x4 a, xxh_u32x4 b)
3158{
3159    xxh_u64x2 result;
3160    __asm__("vmuleuw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
3161    return result;
3162}
3163# endif /* XXH_vec_mulo, XXH_vec_mule */
3164#endif /* XXH_VECTOR == XXH_VSX */
3165
3166
3167/* prefetch
3168 * can be disabled, by declaring XXH_NO_PREFETCH build macro */
3169#if defined(XXH_NO_PREFETCH)
3170#  define XXH_PREFETCH(ptr)  (void)(ptr)  /* disabled */
3171#else
3172#  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_IX86))  /* _mm_prefetch() not defined outside of x86/x64 */
3173#    include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
3174#    define XXH_PREFETCH(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
3175#  elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
3176#    define XXH_PREFETCH(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
3177#  else
3178#    define XXH_PREFETCH(ptr) (void)(ptr)  /* disabled */
3179#  endif
3180#endif  /* XXH_NO_PREFETCH */
3181
3182
3183/* ==========================================
3184 * XXH3 default settings
3185 * ========================================== */
3186
3187#define XXH_SECRET_DEFAULT_SIZE 192   /* minimum XXH3_SECRET_SIZE_MIN */
3188
3189#if (XXH_SECRET_DEFAULT_SIZE < XXH3_SECRET_SIZE_MIN)
3190#  error "default keyset is not large enough"
3191#endif
3192
3193/*! Pseudorandom secret taken directly from FARSH. */
3194XXH_ALIGN(64) static const xxh_u8 XXH3_kSecret[XXH_SECRET_DEFAULT_SIZE] = {
3195    0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c,
3196    0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f,
3197    0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,
3198    0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c,
3199    0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3,
3200    0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,
3201    0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d,
3202    0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64,
3203    0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,
3204    0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e,
3205    0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce,
3206    0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,
3207};
3208
3209
3210#ifdef XXH_OLD_NAMES
3211#  define kSecret XXH3_kSecret
3212#endif
3213
3214#ifdef XXH_DOXYGEN
3215/*!
3216 * @brief Calculates a 32-bit to 64-bit long multiply.
3217 *
3218 * Implemented as a macro.
3219 *
3220 * Wraps `__emulu` on MSVC x86 because it tends to call `__allmul` when it doesn't
3221 * need to (but it shouldn't need to anyways, it is about 7 instructions to do
3222 * a 64x64 multiply...). Since we know that this will _always_ emit `MULL`, we
3223 * use that instead of the normal method.
3224 *
3225 * If you are compiling for platforms like Thumb-1 and don't have a better option,
3226 * you may also want to write your own long multiply routine here.
3227 *
3228 * @param x, y Numbers to be multiplied
3229 * @return 64-bit product of the low 32 bits of @p x and @p y.
3230 */
3231XXH_FORCE_INLINE xxh_u64
3232XXH_mult32to64(xxh_u64 x, xxh_u64 y)
3233{
3234   return (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF);
3235}
3236#elif defined(_MSC_VER) && defined(_M_IX86)
3237#    define XXH_mult32to64(x, y) __emulu((unsigned)(x), (unsigned)(y))
3238#else
3239/*
3240 * Downcast + upcast is usually better than masking on older compilers like
3241 * GCC 4.2 (especially 32-bit ones), all without affecting newer compilers.
3242 *
3243 * The other method, (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF), will AND both operands
3244 * and perform a full 64x64 multiply -- entirely redundant on 32-bit.
3245 */
3246#    define XXH_mult32to64(x, y) ((xxh_u64)(xxh_u32)(x) * (xxh_u64)(xxh_u32)(y))
3247#endif
3248
3249/*!
3250 * @brief Calculates a 64->128-bit long multiply.
3251 *
3252 * Uses `__uint128_t` and `_umul128` if available, otherwise uses a scalar
3253 * version.
3254 *
3255 * @param lhs , rhs The 64-bit integers to be multiplied
3256 * @return The 128-bit result represented in an @ref XXH128_hash_t.
3257 */
3258static XXH128_hash_t
3259XXH_mult64to128(xxh_u64 lhs, xxh_u64 rhs)
3260{
3261    /*
3262     * GCC/Clang __uint128_t method.
3263     *
3264     * On most 64-bit targets, GCC and Clang define a __uint128_t type.
3265     * This is usually the best way as it usually uses a native long 64-bit
3266     * multiply, such as MULQ on x86_64 or MUL + UMULH on aarch64.
3267     *
3268     * Usually.
3269     *
3270     * Despite being a 32-bit platform, Clang (and emscripten) define this type
3271     * despite not having the arithmetic for it. This results in a laggy
3272     * compiler builtin call which calculates a full 128-bit multiply.
3273     * In that case it is best to use the portable one.
3274     * https://github.com/Cyan4973/xxHash/issues/211#issuecomment-515575677
3275     */
3276#if (defined(__GNUC__) || defined(__clang__)) && !defined(__wasm__) \
3277    && defined(__SIZEOF_INT128__) \
3278    || (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)
3279
3280    __uint128_t const product = (__uint128_t)lhs * (__uint128_t)rhs;
3281    XXH128_hash_t r128;
3282    r128.low64  = (xxh_u64)(product);
3283    r128.high64 = (xxh_u64)(product >> 64);
3284    return r128;
3285
3286    /*
3287     * MSVC for x64's _umul128 method.
3288     *
3289     * xxh_u64 _umul128(xxh_u64 Multiplier, xxh_u64 Multiplicand, xxh_u64 *HighProduct);
3290     *
3291     * This compiles to single operand MUL on x64.
3292     */
3293#elif (defined(_M_X64) || defined(_M_IA64)) && !defined(_M_ARM64EC)
3294
3295#ifndef _MSC_VER
3296#   pragma intrinsic(_umul128)
3297#endif
3298    xxh_u64 product_high;
3299    xxh_u64 const product_low = _umul128(lhs, rhs, &product_high);
3300    XXH128_hash_t r128;
3301    r128.low64  = product_low;
3302    r128.high64 = product_high;
3303    return r128;
3304
3305    /*
3306     * MSVC for ARM64's __umulh method.
3307     *
3308     * This compiles to the same MUL + UMULH as GCC/Clang's __uint128_t method.
3309     */
3310#elif defined(_M_ARM64) || defined(_M_ARM64EC)
3311
3312#ifndef _MSC_VER
3313#   pragma intrinsic(__umulh)
3314#endif
3315    XXH128_hash_t r128;
3316    r128.low64  = lhs * rhs;
3317    r128.high64 = __umulh(lhs, rhs);
3318    return r128;
3319
3320#else
3321    /*
3322     * Portable scalar method. Optimized for 32-bit and 64-bit ALUs.
3323     *
3324     * This is a fast and simple grade school multiply, which is shown below
3325     * with base 10 arithmetic instead of base 0x100000000.
3326     *
3327     *           9 3 // D2 lhs = 93
3328     *         x 7 5 // D2 rhs = 75
3329     *     ----------
3330     *           1 5 // D2 lo_lo = (93 % 10) * (75 % 10) = 15
3331     *         4 5 | // D2 hi_lo = (93 / 10) * (75 % 10) = 45
3332     *         2 1 | // D2 lo_hi = (93 % 10) * (75 / 10) = 21
3333     *     + 6 3 | | // D2 hi_hi = (93 / 10) * (75 / 10) = 63
3334     *     ---------
3335     *         2 7 | // D2 cross = (15 / 10) + (45 % 10) + 21 = 27
3336     *     + 6 7 | | // D2 upper = (27 / 10) + (45 / 10) + 63 = 67
3337     *     ---------
3338     *       6 9 7 5 // D4 res = (27 * 10) + (15 % 10) + (67 * 100) = 6975
3339     *
3340     * The reasons for adding the products like this are:
3341     *  1. It avoids manual carry tracking. Just like how
3342     *     (9 * 9) + 9 + 9 = 99, the same applies with this for UINT64_MAX.
3343     *     This avoids a lot of complexity.
3344     *
3345     *  2. It hints for, and on Clang, compiles to, the powerful UMAAL
3346     *     instruction available in ARM's Digital Signal Processing extension
3347     *     in 32-bit ARMv6 and later, which is shown below:
3348     *
3349     *         void UMAAL(xxh_u32 *RdLo, xxh_u32 *RdHi, xxh_u32 Rn, xxh_u32 Rm)
3350     *         {
3351     *             xxh_u64 product = (xxh_u64)*RdLo * (xxh_u64)*RdHi + Rn + Rm;
3352     *             *RdLo = (xxh_u32)(product & 0xFFFFFFFF);
3353     *             *RdHi = (xxh_u32)(product >> 32);
3354     *         }
3355     *
3356     *     This instruction was designed for efficient long multiplication, and
3357     *     allows this to be calculated in only 4 instructions at speeds
3358     *     comparable to some 64-bit ALUs.
3359     *
3360     *  3. It isn't terrible on other platforms. Usually this will be a couple
3361     *     of 32-bit ADD/ADCs.
3362     */
3363
3364    /* First calculate all of the cross products. */
3365    xxh_u64 const lo_lo = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs & 0xFFFFFFFF);
3366    xxh_u64 const hi_lo = XXH_mult32to64(lhs >> 32,        rhs & 0xFFFFFFFF);
3367    xxh_u64 const lo_hi = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs >> 32);
3368    xxh_u64 const hi_hi = XXH_mult32to64(lhs >> 32,        rhs >> 32);
3369
3370    /* Now add the products together. These will never overflow. */
3371    xxh_u64 const cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi;
3372    xxh_u64 const upper = (hi_lo >> 32) + (cross >> 32)        + hi_hi;
3373    xxh_u64 const lower = (cross << 32) | (lo_lo & 0xFFFFFFFF);
3374
3375    XXH128_hash_t r128;
3376    r128.low64  = lower;
3377    r128.high64 = upper;
3378    return r128;
3379#endif
3380}
3381
3382/*!
3383 * @brief Calculates a 64-bit to 128-bit multiply, then XOR folds it.
3384 *
3385 * The reason for the separate function is to prevent passing too many structs
3386 * around by value. This will hopefully inline the multiply, but we don't force it.
3387 *
3388 * @param lhs , rhs The 64-bit integers to multiply
3389 * @return The low 64 bits of the product XOR'd by the high 64 bits.
3390 * @see XXH_mult64to128()
3391 */
3392static xxh_u64
3393XXH3_mul128_fold64(xxh_u64 lhs, xxh_u64 rhs)
3394{
3395    XXH128_hash_t product = XXH_mult64to128(lhs, rhs);
3396    return product.low64 ^ product.high64;
3397}
3398
3399/*! Seems to produce slightly better code on GCC for some reason. */
3400XXH_FORCE_INLINE xxh_u64 XXH_xorshift64(xxh_u64 v64, int shift)
3401{
3402    XXH_ASSERT(0 <= shift && shift < 64);
3403    return v64 ^ (v64 >> shift);
3404}
3405
3406/*
3407 * This is a fast avalanche stage,
3408 * suitable when input bits are already partially mixed
3409 */
3410static XXH64_hash_t XXH3_avalanche(xxh_u64 h64)
3411{
3412    h64 = XXH_xorshift64(h64, 37);
3413    h64 *= 0x165667919E3779F9ULL;
3414    h64 = XXH_xorshift64(h64, 32);
3415    return h64;
3416}
3417
3418/*
3419 * This is a stronger avalanche,
3420 * inspired by Pelle Evensen's rrmxmx
3421 * preferable when input has not been previously mixed
3422 */
3423static XXH64_hash_t XXH3_rrmxmx(xxh_u64 h64, xxh_u64 len)
3424{
3425    /* this mix is inspired by Pelle Evensen's rrmxmx */
3426    h64 ^= XXH_rotl64(h64, 49) ^ XXH_rotl64(h64, 24);
3427    h64 *= 0x9FB21C651E98DF25ULL;
3428    h64 ^= (h64 >> 35) + len ;
3429    h64 *= 0x9FB21C651E98DF25ULL;
3430    return XXH_xorshift64(h64, 28);
3431}
3432
3433
3434/* ==========================================
3435 * Short keys
3436 * ==========================================
3437 * One of the shortcomings of XXH32 and XXH64 was that their performance was
3438 * sub-optimal on short lengths. It used an iterative algorithm which strongly
3439 * favored lengths that were a multiple of 4 or 8.
3440 *
3441 * Instead of iterating over individual inputs, we use a set of single shot
3442 * functions which piece together a range of lengths and operate in constant time.
3443 *
3444 * Additionally, the number of multiplies has been significantly reduced. This
3445 * reduces latency, especially when emulating 64-bit multiplies on 32-bit.
3446 *
3447 * Depending on the platform, this may or may not be faster than XXH32, but it
3448 * is almost guaranteed to be faster than XXH64.
3449 */
3450
3451/*
3452 * At very short lengths, there isn't enough input to fully hide secrets, or use
3453 * the entire secret.
3454 *
3455 * There is also only a limited amount of mixing we can do before significantly
3456 * impacting performance.
3457 *
3458 * Therefore, we use different sections of the secret and always mix two secret
3459 * samples with an XOR. This should have no effect on performance on the
3460 * seedless or withSeed variants because everything _should_ be constant folded
3461 * by modern compilers.
3462 *
3463 * The XOR mixing hides individual parts of the secret and increases entropy.
3464 *
3465 * This adds an extra layer of strength for custom secrets.
3466 */
3467XXH_FORCE_INLINE XXH64_hash_t
3468XXH3_len_1to3_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3469{
3470    XXH_ASSERT(input != NULL);
3471    XXH_ASSERT(1 <= len && len <= 3);
3472    XXH_ASSERT(secret != NULL);
3473    /*
3474     * len = 1: combined = { input[0], 0x01, input[0], input[0] }
3475     * len = 2: combined = { input[1], 0x02, input[0], input[1] }
3476     * len = 3: combined = { input[2], 0x03, input[0], input[1] }
3477     */
3478    {   xxh_u8  const c1 = input[0];
3479        xxh_u8  const c2 = input[len >> 1];
3480        xxh_u8  const c3 = input[len - 1];
3481        xxh_u32 const combined = ((xxh_u32)c1 << 16) | ((xxh_u32)c2  << 24)
3482                               | ((xxh_u32)c3 <<  0) | ((xxh_u32)len << 8);
3483        xxh_u64 const bitflip = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
3484        xxh_u64 const keyed = (xxh_u64)combined ^ bitflip;
3485        return XXH64_avalanche(keyed);
3486    }
3487}
3488
3489XXH_FORCE_INLINE XXH64_hash_t
3490XXH3_len_4to8_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3491{
3492    XXH_ASSERT(input != NULL);
3493    XXH_ASSERT(secret != NULL);
3494    XXH_ASSERT(4 <= len && len <= 8);
3495    seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
3496    {   xxh_u32 const input1 = XXH_readLE32(input);
3497        xxh_u32 const input2 = XXH_readLE32(input + len - 4);
3498        xxh_u64 const bitflip = (XXH_readLE64(secret+8) ^ XXH_readLE64(secret+16)) - seed;
3499        xxh_u64 const input64 = input2 + (((xxh_u64)input1) << 32);
3500        xxh_u64 const keyed = input64 ^ bitflip;
3501        return XXH3_rrmxmx(keyed, len);
3502    }
3503}
3504
3505XXH_FORCE_INLINE XXH64_hash_t
3506XXH3_len_9to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3507{
3508    XXH_ASSERT(input != NULL);
3509    XXH_ASSERT(secret != NULL);
3510    XXH_ASSERT(9 <= len && len <= 16);
3511    {   xxh_u64 const bitflip1 = (XXH_readLE64(secret+24) ^ XXH_readLE64(secret+32)) + seed;
3512        xxh_u64 const bitflip2 = (XXH_readLE64(secret+40) ^ XXH_readLE64(secret+48)) - seed;
3513        xxh_u64 const input_lo = XXH_readLE64(input)           ^ bitflip1;
3514        xxh_u64 const input_hi = XXH_readLE64(input + len - 8) ^ bitflip2;
3515        xxh_u64 const acc = len
3516                          + XXH_swap64(input_lo) + input_hi
3517                          + XXH3_mul128_fold64(input_lo, input_hi);
3518        return XXH3_avalanche(acc);
3519    }
3520}
3521
3522XXH_FORCE_INLINE XXH64_hash_t
3523XXH3_len_0to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
3524{
3525    XXH_ASSERT(len <= 16);
3526    {   if (XXH_likely(len >  8)) return XXH3_len_9to16_64b(input, len, secret, seed);
3527        if (XXH_likely(len >= 4)) return XXH3_len_4to8_64b(input, len, secret, seed);
3528        if (len) return XXH3_len_1to3_64b(input, len, secret, seed);
3529        return XXH64_avalanche(seed ^ (XXH_readLE64(secret+56) ^ XXH_readLE64(secret+64)));
3530    }
3531}
3532
3533/*
3534 * DISCLAIMER: There are known *seed-dependent* multicollisions here due to
3535 * multiplication by zero, affecting hashes of lengths 17 to 240.
3536 *
3537 * However, they are very unlikely.
3538 *
3539 * Keep this in mind when using the unseeded XXH3_64bits() variant: As with all
3540 * unseeded non-cryptographic hashes, it does not attempt to defend itself
3541 * against specially crafted inputs, only random inputs.
3542 *
3543 * Compared to classic UMAC where a 1 in 2^31 chance of 4 consecutive bytes
3544 * cancelling out the secret is taken an arbitrary number of times (addressed
3545 * in XXH3_accumulate_512), this collision is very unlikely with random inputs
3546 * and/or proper seeding:
3547 *
3548 * This only has a 1 in 2^63 chance of 8 consecutive bytes cancelling out, in a
3549 * function that is only called up to 16 times per hash with up to 240 bytes of
3550 * input.
3551 *
3552 * This is not too bad for a non-cryptographic hash function, especially with
3553 * only 64 bit outputs.
3554 *
3555 * The 128-bit variant (which trades some speed for strength) is NOT affected
3556 * by this, although it is always a good idea to use a proper seed if you care
3557 * about strength.
3558 */
3559XXH_FORCE_INLINE xxh_u64 XXH3_mix16B(const xxh_u8* XXH_RESTRICT input,
3560                                     const xxh_u8* XXH_RESTRICT secret, xxh_u64 seed64)
3561{
3562#if defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
3563  && defined(__i386__) && defined(__SSE2__)  /* x86 + SSE2 */ \
3564  && !defined(XXH_ENABLE_AUTOVECTORIZE)      /* Define to disable like XXH32 hack */
3565    /*
3566     * UGLY HACK:
3567     * GCC for x86 tends to autovectorize the 128-bit multiply, resulting in
3568     * slower code.
3569     *
3570     * By forcing seed64 into a register, we disrupt the cost model and
3571     * cause it to scalarize. See `XXH32_round()`
3572     *
3573     * FIXME: Clang's output is still _much_ faster -- On an AMD Ryzen 3600,
3574     * XXH3_64bits @ len=240 runs at 4.6 GB/s with Clang 9, but 3.3 GB/s on
3575     * GCC 9.2, despite both emitting scalar code.
3576     *
3577     * GCC generates much better scalar code than Clang for the rest of XXH3,
3578     * which is why finding a more optimal codepath is an interest.
3579     */
3580    XXH_COMPILER_GUARD(seed64);
3581#endif
3582    {   xxh_u64 const input_lo = XXH_readLE64(input);
3583        xxh_u64 const input_hi = XXH_readLE64(input+8);
3584        return XXH3_mul128_fold64(
3585            input_lo ^ (XXH_readLE64(secret)   + seed64),
3586            input_hi ^ (XXH_readLE64(secret+8) - seed64)
3587        );
3588    }
3589}
3590
3591/* For mid range keys, XXH3 uses a Mum-hash variant. */
3592XXH_FORCE_INLINE XXH64_hash_t
3593XXH3_len_17to128_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
3594                     const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
3595                     XXH64_hash_t seed)
3596{
3597    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
3598    XXH_ASSERT(16 < len && len <= 128);
3599
3600    {   xxh_u64 acc = len * XXH_PRIME64_1;
3601        if (len > 32) {
3602            if (len > 64) {
3603                if (len > 96) {
3604                    acc += XXH3_mix16B(input+48, secret+96, seed);
3605                    acc += XXH3_mix16B(input+len-64, secret+112, seed);
3606                }
3607                acc += XXH3_mix16B(input+32, secret+64, seed);
3608                acc += XXH3_mix16B(input+len-48, secret+80, seed);
3609            }
3610            acc += XXH3_mix16B(input+16, secret+32, seed);
3611            acc += XXH3_mix16B(input+len-32, secret+48, seed);
3612        }
3613        acc += XXH3_mix16B(input+0, secret+0, seed);
3614        acc += XXH3_mix16B(input+len-16, secret+16, seed);
3615
3616        return XXH3_avalanche(acc);
3617    }
3618}
3619
3620#define XXH3_MIDSIZE_MAX 240
3621
3622XXH_NO_INLINE XXH64_hash_t
3623XXH3_len_129to240_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
3624                      const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
3625                      XXH64_hash_t seed)
3626{
3627    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
3628    XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
3629
3630    #define XXH3_MIDSIZE_STARTOFFSET 3
3631    #define XXH3_MIDSIZE_LASTOFFSET  17
3632
3633    {   xxh_u64 acc = len * XXH_PRIME64_1;
3634        int const nbRounds = (int)len / 16;
3635        int i;
3636        for (i=0; i<8; i++) {
3637            acc += XXH3_mix16B(input+(16*i), secret+(16*i), seed);
3638        }
3639        acc = XXH3_avalanche(acc);
3640        XXH_ASSERT(nbRounds >= 8);
3641#if defined(__clang__)                                /* Clang */ \
3642    && (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */ \
3643    && !defined(XXH_ENABLE_AUTOVECTORIZE)             /* Define to disable */
3644        /*
3645         * UGLY HACK:
3646         * Clang for ARMv7-A tries to vectorize this loop, similar to GCC x86.
3647         * In everywhere else, it uses scalar code.
3648         *
3649         * For 64->128-bit multiplies, even if the NEON was 100% optimal, it
3650         * would still be slower than UMAAL (see XXH_mult64to128).
3651         *
3652         * Unfortunately, Clang doesn't handle the long multiplies properly and
3653         * converts them to the nonexistent "vmulq_u64" intrinsic, which is then
3654         * scalarized into an ugly mess of VMOV.32 instructions.
3655         *
3656         * This mess is difficult to avoid without turning autovectorization
3657         * off completely, but they are usually relatively minor and/or not
3658         * worth it to fix.
3659         *
3660         * This loop is the easiest to fix, as unlike XXH32, this pragma
3661         * _actually works_ because it is a loop vectorization instead of an
3662         * SLP vectorization.
3663         */
3664        #pragma clang loop vectorize(disable)
3665#endif
3666        for (i=8 ; i < nbRounds; i++) {
3667            acc += XXH3_mix16B(input+(16*i), secret+(16*(i-8)) + XXH3_MIDSIZE_STARTOFFSET, seed);
3668        }
3669        /* last bytes */
3670        acc += XXH3_mix16B(input + len - 16, secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET, seed);
3671        return XXH3_avalanche(acc);
3672    }
3673}
3674
3675
3676/* =======     Long Keys     ======= */
3677
3678#define XXH_STRIPE_LEN 64
3679#define XXH_SECRET_CONSUME_RATE 8   /* nb of secret bytes consumed at each accumulation */
3680#define XXH_ACC_NB (XXH_STRIPE_LEN / sizeof(xxh_u64))
3681
3682#ifdef XXH_OLD_NAMES
3683#  define STRIPE_LEN XXH_STRIPE_LEN
3684#  define ACC_NB XXH_ACC_NB
3685#endif
3686
3687XXH_FORCE_INLINE void XXH_writeLE64(void* dst, xxh_u64 v64)
3688{
3689    if (!XXH_CPU_LITTLE_ENDIAN) v64 = XXH_swap64(v64);
3690    XXH_memcpy(dst, &v64, sizeof(v64));
3691}
3692
3693/* Several intrinsic functions below are supposed to accept __int64 as argument,
3694 * as documented in https://software.intel.com/sites/landingpage/IntrinsicsGuide/ .
3695 * However, several environments do not define __int64 type,
3696 * requiring a workaround.
3697 */
3698#if !defined (__VMS) \
3699  && (defined (__cplusplus) \
3700  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
3701    typedef int64_t xxh_i64;
3702#else
3703    /* the following type must have a width of 64-bit */
3704    typedef long long xxh_i64;
3705#endif
3706
3707
3708/*
3709 * XXH3_accumulate_512 is the tightest loop for long inputs, and it is the most optimized.
3710 *
3711 * It is a hardened version of UMAC, based off of FARSH's implementation.
3712 *
3713 * This was chosen because it adapts quite well to 32-bit, 64-bit, and SIMD
3714 * implementations, and it is ridiculously fast.
3715 *
3716 * We harden it by mixing the original input to the accumulators as well as the product.
3717 *
3718 * This means that in the (relatively likely) case of a multiply by zero, the
3719 * original input is preserved.
3720 *
3721 * On 128-bit inputs, we swap 64-bit pairs when we add the input to improve
3722 * cross-pollination, as otherwise the upper and lower halves would be
3723 * essentially independent.
3724 *
3725 * This doesn't matter on 64-bit hashes since they all get merged together in
3726 * the end, so we skip the extra step.
3727 *
3728 * Both XXH3_64bits and XXH3_128bits use this subroutine.
3729 */
3730
3731#if (XXH_VECTOR == XXH_AVX512) \
3732     || (defined(XXH_DISPATCH_AVX512) && XXH_DISPATCH_AVX512 != 0)
3733
3734#ifndef XXH_TARGET_AVX512
3735# define XXH_TARGET_AVX512  /* disable attribute target */
3736#endif
3737
3738XXH_FORCE_INLINE XXH_TARGET_AVX512 void
3739XXH3_accumulate_512_avx512(void* XXH_RESTRICT acc,
3740                     const void* XXH_RESTRICT input,
3741                     const void* XXH_RESTRICT secret)
3742{
3743    __m512i* const xacc = (__m512i *) acc;
3744    XXH_ASSERT((((size_t)acc) & 63) == 0);
3745    XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));
3746
3747    {
3748        /* data_vec    = input[0]; */
3749        __m512i const data_vec    = _mm512_loadu_si512   (input);
3750        /* key_vec     = secret[0]; */
3751        __m512i const key_vec     = _mm512_loadu_si512   (secret);
3752        /* data_key    = data_vec ^ key_vec; */
3753        __m512i const data_key    = _mm512_xor_si512     (data_vec, key_vec);
3754        /* data_key_lo = data_key >> 32; */
3755        __m512i const data_key_lo = _mm512_shuffle_epi32 (data_key, (_MM_PERM_ENUM)_MM_SHUFFLE(0, 3, 0, 1));
3756        /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
3757        __m512i const product     = _mm512_mul_epu32     (data_key, data_key_lo);
3758        /* xacc[0] += swap(data_vec); */
3759        __m512i const data_swap = _mm512_shuffle_epi32(data_vec, (_MM_PERM_ENUM)_MM_SHUFFLE(1, 0, 3, 2));
3760        __m512i const sum       = _mm512_add_epi64(*xacc, data_swap);
3761        /* xacc[0] += product; */
3762        *xacc = _mm512_add_epi64(product, sum);
3763    }
3764}
3765
3766/*
3767 * XXH3_scrambleAcc: Scrambles the accumulators to improve mixing.
3768 *
3769 * Multiplication isn't perfect, as explained by Google in HighwayHash:
3770 *
3771 *  // Multiplication mixes/scrambles bytes 0-7 of the 64-bit result to
3772 *  // varying degrees. In descending order of goodness, bytes
3773 *  // 3 4 2 5 1 6 0 7 have quality 228 224 164 160 100 96 36 32.
3774 *  // As expected, the upper and lower bytes are much worse.
3775 *
3776 * Source: https://github.com/google/highwayhash/blob/0aaf66b/highwayhash/hh_avx2.h#L291
3777 *
3778 * Since our algorithm uses a pseudorandom secret to add some variance into the
3779 * mix, we don't need to (or want to) mix as often or as much as HighwayHash does.
3780 *
3781 * This isn't as tight as XXH3_accumulate, but still written in SIMD to avoid
3782 * extraction.
3783 *
3784 * Both XXH3_64bits and XXH3_128bits use this subroutine.
3785 */
3786
3787XXH_FORCE_INLINE XXH_TARGET_AVX512 void
3788XXH3_scrambleAcc_avx512(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
3789{
3790    XXH_ASSERT((((size_t)acc) & 63) == 0);
3791    XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));
3792    {   __m512i* const xacc = (__m512i*) acc;
3793        const __m512i prime32 = _mm512_set1_epi32((int)XXH_PRIME32_1);
3794
3795        /* xacc[0] ^= (xacc[0] >> 47) */
3796        __m512i const acc_vec     = *xacc;
3797        __m512i const shifted     = _mm512_srli_epi64    (acc_vec, 47);
3798        __m512i const data_vec    = _mm512_xor_si512     (acc_vec, shifted);
3799        /* xacc[0] ^= secret; */
3800        __m512i const key_vec     = _mm512_loadu_si512   (secret);
3801        __m512i const data_key    = _mm512_xor_si512     (data_vec, key_vec);
3802
3803        /* xacc[0] *= XXH_PRIME32_1; */
3804        __m512i const data_key_hi = _mm512_shuffle_epi32 (data_key, (_MM_PERM_ENUM)_MM_SHUFFLE(0, 3, 0, 1));
3805        __m512i const prod_lo     = _mm512_mul_epu32     (data_key, prime32);
3806        __m512i const prod_hi     = _mm512_mul_epu32     (data_key_hi, prime32);
3807        *xacc = _mm512_add_epi64(prod_lo, _mm512_slli_epi64(prod_hi, 32));
3808    }
3809}
3810
3811XXH_FORCE_INLINE XXH_TARGET_AVX512 void
3812XXH3_initCustomSecret_avx512(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
3813{
3814    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 63) == 0);
3815    XXH_STATIC_ASSERT(XXH_SEC_ALIGN == 64);
3816    XXH_ASSERT(((size_t)customSecret & 63) == 0);
3817    (void)(&XXH_writeLE64);
3818    {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m512i);
3819        __m512i const seed = _mm512_mask_set1_epi64(_mm512_set1_epi64((xxh_i64)seed64), 0xAA, (xxh_i64)(0U - seed64));
3820
3821        const __m512i* const src  = (const __m512i*) ((const void*) XXH3_kSecret);
3822              __m512i* const dest = (      __m512i*) customSecret;
3823        int i;
3824        XXH_ASSERT(((size_t)src & 63) == 0); /* control alignment */
3825        XXH_ASSERT(((size_t)dest & 63) == 0);
3826        for (i=0; i < nbRounds; ++i) {
3827            /* GCC has a bug, _mm512_stream_load_si512 accepts 'void*', not 'void const*',
3828             * this will warn "discards 'const' qualifier". */
3829            union {
3830                const __m512i* cp;
3831                void* p;
3832            } remote_const_void;
3833            remote_const_void.cp = src + i;
3834            dest[i] = _mm512_add_epi64(_mm512_stream_load_si512(remote_const_void.p), seed);
3835    }   }
3836}
3837
3838#endif
3839
3840#if (XXH_VECTOR == XXH_AVX2) \
3841    || (defined(XXH_DISPATCH_AVX2) && XXH_DISPATCH_AVX2 != 0)
3842
3843#ifndef XXH_TARGET_AVX2
3844# define XXH_TARGET_AVX2  /* disable attribute target */
3845#endif
3846
3847XXH_FORCE_INLINE XXH_TARGET_AVX2 void
3848XXH3_accumulate_512_avx2( void* XXH_RESTRICT acc,
3849                    const void* XXH_RESTRICT input,
3850                    const void* XXH_RESTRICT secret)
3851{
3852    XXH_ASSERT((((size_t)acc) & 31) == 0);
3853    {   __m256i* const xacc    =       (__m256i *) acc;
3854        /* Unaligned. This is mainly for pointer arithmetic, and because
3855         * _mm256_loadu_si256 requires  a const __m256i * pointer for some reason. */
3856        const         __m256i* const xinput  = (const __m256i *) input;
3857        /* Unaligned. This is mainly for pointer arithmetic, and because
3858         * _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
3859        const         __m256i* const xsecret = (const __m256i *) secret;
3860
3861        size_t i;
3862        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
3863            /* data_vec    = xinput[i]; */
3864            __m256i const data_vec    = _mm256_loadu_si256    (xinput+i);
3865            /* key_vec     = xsecret[i]; */
3866            __m256i const key_vec     = _mm256_loadu_si256   (xsecret+i);
3867            /* data_key    = data_vec ^ key_vec; */
3868            __m256i const data_key    = _mm256_xor_si256     (data_vec, key_vec);
3869            /* data_key_lo = data_key >> 32; */
3870            __m256i const data_key_lo = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
3871            /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
3872            __m256i const product     = _mm256_mul_epu32     (data_key, data_key_lo);
3873            /* xacc[i] += swap(data_vec); */
3874            __m256i const data_swap = _mm256_shuffle_epi32(data_vec, _MM_SHUFFLE(1, 0, 3, 2));
3875            __m256i const sum       = _mm256_add_epi64(xacc[i], data_swap);
3876            /* xacc[i] += product; */
3877            xacc[i] = _mm256_add_epi64(product, sum);
3878    }   }
3879}
3880
3881XXH_FORCE_INLINE XXH_TARGET_AVX2 void
3882XXH3_scrambleAcc_avx2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
3883{
3884    XXH_ASSERT((((size_t)acc) & 31) == 0);
3885    {   __m256i* const xacc = (__m256i*) acc;
3886        /* Unaligned. This is mainly for pointer arithmetic, and because
3887         * _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
3888        const         __m256i* const xsecret = (const __m256i *) secret;
3889        const __m256i prime32 = _mm256_set1_epi32((int)XXH_PRIME32_1);
3890
3891        size_t i;
3892        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
3893            /* xacc[i] ^= (xacc[i] >> 47) */
3894            __m256i const acc_vec     = xacc[i];
3895            __m256i const shifted     = _mm256_srli_epi64    (acc_vec, 47);
3896            __m256i const data_vec    = _mm256_xor_si256     (acc_vec, shifted);
3897            /* xacc[i] ^= xsecret; */
3898            __m256i const key_vec     = _mm256_loadu_si256   (xsecret+i);
3899            __m256i const data_key    = _mm256_xor_si256     (data_vec, key_vec);
3900
3901            /* xacc[i] *= XXH_PRIME32_1; */
3902            __m256i const data_key_hi = _mm256_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
3903            __m256i const prod_lo     = _mm256_mul_epu32     (data_key, prime32);
3904            __m256i const prod_hi     = _mm256_mul_epu32     (data_key_hi, prime32);
3905            xacc[i] = _mm256_add_epi64(prod_lo, _mm256_slli_epi64(prod_hi, 32));
3906        }
3907    }
3908}
3909
3910XXH_FORCE_INLINE XXH_TARGET_AVX2 void XXH3_initCustomSecret_avx2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
3911{
3912    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 31) == 0);
3913    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE / sizeof(__m256i)) == 6);
3914    XXH_STATIC_ASSERT(XXH_SEC_ALIGN <= 64);
3915    (void)(&XXH_writeLE64);
3916    XXH_PREFETCH(customSecret);
3917    {   __m256i const seed = _mm256_set_epi64x((xxh_i64)(0U - seed64), (xxh_i64)seed64, (xxh_i64)(0U - seed64), (xxh_i64)seed64);
3918
3919        const __m256i* const src  = (const __m256i*) ((const void*) XXH3_kSecret);
3920              __m256i*       dest = (      __m256i*) customSecret;
3921
3922#       if defined(__GNUC__) || defined(__clang__)
3923        /*
3924         * On GCC & Clang, marking 'dest' as modified will cause the compiler:
3925         *   - do not extract the secret from sse registers in the internal loop
3926         *   - use less common registers, and avoid pushing these reg into stack
3927         */
3928        XXH_COMPILER_GUARD(dest);
3929#       endif
3930        XXH_ASSERT(((size_t)src & 31) == 0); /* control alignment */
3931        XXH_ASSERT(((size_t)dest & 31) == 0);
3932
3933        /* GCC -O2 need unroll loop manually */
3934        dest[0] = _mm256_add_epi64(_mm256_stream_load_si256(src+0), seed);
3935        dest[1] = _mm256_add_epi64(_mm256_stream_load_si256(src+1), seed);
3936        dest[2] = _mm256_add_epi64(_mm256_stream_load_si256(src+2), seed);
3937        dest[3] = _mm256_add_epi64(_mm256_stream_load_si256(src+3), seed);
3938        dest[4] = _mm256_add_epi64(_mm256_stream_load_si256(src+4), seed);
3939        dest[5] = _mm256_add_epi64(_mm256_stream_load_si256(src+5), seed);
3940    }
3941}
3942
3943#endif
3944
3945/* x86dispatch always generates SSE2 */
3946#if (XXH_VECTOR == XXH_SSE2) || defined(XXH_X86DISPATCH)
3947
3948#ifndef XXH_TARGET_SSE2
3949# define XXH_TARGET_SSE2  /* disable attribute target */
3950#endif
3951
3952XXH_FORCE_INLINE XXH_TARGET_SSE2 void
3953XXH3_accumulate_512_sse2( void* XXH_RESTRICT acc,
3954                    const void* XXH_RESTRICT input,
3955                    const void* XXH_RESTRICT secret)
3956{
3957    /* SSE2 is just a half-scale version of the AVX2 version. */
3958    XXH_ASSERT((((size_t)acc) & 15) == 0);
3959    {   __m128i* const xacc    =       (__m128i *) acc;
3960        /* Unaligned. This is mainly for pointer arithmetic, and because
3961         * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
3962        const         __m128i* const xinput  = (const __m128i *) input;
3963        /* Unaligned. This is mainly for pointer arithmetic, and because
3964         * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
3965        const         __m128i* const xsecret = (const __m128i *) secret;
3966
3967        size_t i;
3968        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
3969            /* data_vec    = xinput[i]; */
3970            __m128i const data_vec    = _mm_loadu_si128   (xinput+i);
3971            /* key_vec     = xsecret[i]; */
3972            __m128i const key_vec     = _mm_loadu_si128   (xsecret+i);
3973            /* data_key    = data_vec ^ key_vec; */
3974            __m128i const data_key    = _mm_xor_si128     (data_vec, key_vec);
3975            /* data_key_lo = data_key >> 32; */
3976            __m128i const data_key_lo = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
3977            /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
3978            __m128i const product     = _mm_mul_epu32     (data_key, data_key_lo);
3979            /* xacc[i] += swap(data_vec); */
3980            __m128i const data_swap = _mm_shuffle_epi32(data_vec, _MM_SHUFFLE(1,0,3,2));
3981            __m128i const sum       = _mm_add_epi64(xacc[i], data_swap);
3982            /* xacc[i] += product; */
3983            xacc[i] = _mm_add_epi64(product, sum);
3984    }   }
3985}
3986
3987XXH_FORCE_INLINE XXH_TARGET_SSE2 void
3988XXH3_scrambleAcc_sse2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
3989{
3990    XXH_ASSERT((((size_t)acc) & 15) == 0);
3991    {   __m128i* const xacc = (__m128i*) acc;
3992        /* Unaligned. This is mainly for pointer arithmetic, and because
3993         * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
3994        const         __m128i* const xsecret = (const __m128i *) secret;
3995        const __m128i prime32 = _mm_set1_epi32((int)XXH_PRIME32_1);
3996
3997        size_t i;
3998        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
3999            /* xacc[i] ^= (xacc[i] >> 47) */
4000            __m128i const acc_vec     = xacc[i];
4001            __m128i const shifted     = _mm_srli_epi64    (acc_vec, 47);
4002            __m128i const data_vec    = _mm_xor_si128     (acc_vec, shifted);
4003            /* xacc[i] ^= xsecret[i]; */
4004            __m128i const key_vec     = _mm_loadu_si128   (xsecret+i);
4005            __m128i const data_key    = _mm_xor_si128     (data_vec, key_vec);
4006
4007            /* xacc[i] *= XXH_PRIME32_1; */
4008            __m128i const data_key_hi = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
4009            __m128i const prod_lo     = _mm_mul_epu32     (data_key, prime32);
4010            __m128i const prod_hi     = _mm_mul_epu32     (data_key_hi, prime32);
4011            xacc[i] = _mm_add_epi64(prod_lo, _mm_slli_epi64(prod_hi, 32));
4012        }
4013    }
4014}
4015
4016XXH_FORCE_INLINE XXH_TARGET_SSE2 void XXH3_initCustomSecret_sse2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
4017{
4018    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
4019    (void)(&XXH_writeLE64);
4020    {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m128i);
4021
4022#       if defined(_MSC_VER) && defined(_M_IX86) && _MSC_VER < 1900
4023        /* MSVC 32bit mode does not support _mm_set_epi64x before 2015 */
4024        XXH_ALIGN(16) const xxh_i64 seed64x2[2] = { (xxh_i64)seed64, (xxh_i64)(0U - seed64) };
4025        __m128i const seed = _mm_load_si128((__m128i const*)seed64x2);
4026#       else
4027        __m128i const seed = _mm_set_epi64x((xxh_i64)(0U - seed64), (xxh_i64)seed64);
4028#       endif
4029        int i;
4030
4031        const void* const src16 = XXH3_kSecret;
4032        __m128i* dst16 = (__m128i*) customSecret;
4033#       if defined(__GNUC__) || defined(__clang__)
4034        /*
4035         * On GCC & Clang, marking 'dest' as modified will cause the compiler:
4036         *   - do not extract the secret from sse registers in the internal loop
4037         *   - use less common registers, and avoid pushing these reg into stack
4038         */
4039        XXH_COMPILER_GUARD(dst16);
4040#       endif
4041        XXH_ASSERT(((size_t)src16 & 15) == 0); /* control alignment */
4042        XXH_ASSERT(((size_t)dst16 & 15) == 0);
4043
4044        for (i=0; i < nbRounds; ++i) {
4045            dst16[i] = _mm_add_epi64(_mm_load_si128((const __m128i *)src16+i), seed);
4046    }   }
4047}
4048
4049#endif
4050
4051#if (XXH_VECTOR == XXH_NEON)
4052
4053/* forward declarations for the scalar routines */
4054XXH_FORCE_INLINE void
4055XXH3_scalarRound(void* XXH_RESTRICT acc, void const* XXH_RESTRICT input,
4056                 void const* XXH_RESTRICT secret, size_t lane);
4057
4058XXH_FORCE_INLINE void
4059XXH3_scalarScrambleRound(void* XXH_RESTRICT acc,
4060                         void const* XXH_RESTRICT secret, size_t lane);
4061
4062/*!
4063 * @internal
4064 * @brief The bulk processing loop for NEON.
4065 *
4066 * The NEON code path is actually partially scalar when running on AArch64. This
4067 * is to optimize the pipelining and can have up to 15% speedup depending on the
4068 * CPU, and it also mitigates some GCC codegen issues.
4069 *
4070 * @see XXH3_NEON_LANES for configuring this and details about this optimization.
4071 */
4072XXH_FORCE_INLINE void
4073XXH3_accumulate_512_neon( void* XXH_RESTRICT acc,
4074                    const void* XXH_RESTRICT input,
4075                    const void* XXH_RESTRICT secret)
4076{
4077    XXH_ASSERT((((size_t)acc) & 15) == 0);
4078    XXH_STATIC_ASSERT(XXH3_NEON_LANES > 0 && XXH3_NEON_LANES <= XXH_ACC_NB && XXH3_NEON_LANES % 2 == 0);
4079    {
4080        uint64x2_t* const xacc = (uint64x2_t *) acc;
4081        /* We don't use a uint32x4_t pointer because it causes bus errors on ARMv7. */
4082        uint8_t const* const xinput = (const uint8_t *) input;
4083        uint8_t const* const xsecret  = (const uint8_t *) secret;
4084
4085        size_t i;
4086        /* NEON for the first few lanes (these loops are normally interleaved) */
4087        for (i=0; i < XXH3_NEON_LANES / 2; i++) {
4088            /* data_vec = xinput[i]; */
4089            uint8x16_t data_vec    = vld1q_u8(xinput  + (i * 16));
4090            /* key_vec  = xsecret[i];  */
4091            uint8x16_t key_vec     = vld1q_u8(xsecret + (i * 16));
4092            uint64x2_t data_key;
4093            uint32x2_t data_key_lo, data_key_hi;
4094            /* xacc[i] += swap(data_vec); */
4095            uint64x2_t const data64  = vreinterpretq_u64_u8(data_vec);
4096            uint64x2_t const swapped = vextq_u64(data64, data64, 1);
4097            xacc[i] = vaddq_u64 (xacc[i], swapped);
4098            /* data_key = data_vec ^ key_vec; */
4099            data_key = vreinterpretq_u64_u8(veorq_u8(data_vec, key_vec));
4100            /* data_key_lo = (uint32x2_t) (data_key & 0xFFFFFFFF);
4101             * data_key_hi = (uint32x2_t) (data_key >> 32);
4102             * data_key = UNDEFINED; */
4103            XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
4104            /* xacc[i] += (uint64x2_t) data_key_lo * (uint64x2_t) data_key_hi; */
4105            xacc[i] = vmlal_u32 (xacc[i], data_key_lo, data_key_hi);
4106
4107        }
4108        /* Scalar for the remainder. This may be a zero iteration loop. */
4109        for (i = XXH3_NEON_LANES; i < XXH_ACC_NB; i++) {
4110            XXH3_scalarRound(acc, input, secret, i);
4111        }
4112    }
4113}
4114
4115XXH_FORCE_INLINE void
4116XXH3_scrambleAcc_neon(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
4117{
4118    XXH_ASSERT((((size_t)acc) & 15) == 0);
4119
4120    {   uint64x2_t* xacc       = (uint64x2_t*) acc;
4121        uint8_t const* xsecret = (uint8_t const*) secret;
4122        uint32x2_t prime       = vdup_n_u32 (XXH_PRIME32_1);
4123
4124        size_t i;
4125        /* NEON for the first few lanes (these loops are normally interleaved) */
4126        for (i=0; i < XXH3_NEON_LANES / 2; i++) {
4127            /* xacc[i] ^= (xacc[i] >> 47); */
4128            uint64x2_t acc_vec  = xacc[i];
4129            uint64x2_t shifted  = vshrq_n_u64 (acc_vec, 47);
4130            uint64x2_t data_vec = veorq_u64   (acc_vec, shifted);
4131
4132            /* xacc[i] ^= xsecret[i]; */
4133            uint8x16_t key_vec  = vld1q_u8    (xsecret + (i * 16));
4134            uint64x2_t data_key = veorq_u64   (data_vec, vreinterpretq_u64_u8(key_vec));
4135
4136            /* xacc[i] *= XXH_PRIME32_1 */
4137            uint32x2_t data_key_lo, data_key_hi;
4138            /* data_key_lo = (uint32x2_t) (xacc[i] & 0xFFFFFFFF);
4139             * data_key_hi = (uint32x2_t) (xacc[i] >> 32);
4140             * xacc[i] = UNDEFINED; */
4141            XXH_SPLIT_IN_PLACE(data_key, data_key_lo, data_key_hi);
4142            {   /*
4143                 * prod_hi = (data_key >> 32) * XXH_PRIME32_1;
4144                 *
4145                 * Avoid vmul_u32 + vshll_n_u32 since Clang 6 and 7 will
4146                 * incorrectly "optimize" this:
4147                 *   tmp     = vmul_u32(vmovn_u64(a), vmovn_u64(b));
4148                 *   shifted = vshll_n_u32(tmp, 32);
4149                 * to this:
4150                 *   tmp     = "vmulq_u64"(a, b); // no such thing!
4151                 *   shifted = vshlq_n_u64(tmp, 32);
4152                 *
4153                 * However, unlike SSE, Clang lacks a 64-bit multiply routine
4154                 * for NEON, and it scalarizes two 64-bit multiplies instead.
4155                 *
4156                 * vmull_u32 has the same timing as vmul_u32, and it avoids
4157                 * this bug completely.
4158                 * See https://bugs.llvm.org/show_bug.cgi?id=39967
4159                 */
4160                uint64x2_t prod_hi = vmull_u32 (data_key_hi, prime);
4161                /* xacc[i] = prod_hi << 32; */
4162                xacc[i] = vshlq_n_u64(prod_hi, 32);
4163                /* xacc[i] += (prod_hi & 0xFFFFFFFF) * XXH_PRIME32_1; */
4164                xacc[i] = vmlal_u32(xacc[i], data_key_lo, prime);
4165            }
4166        }
4167        /* Scalar for the remainder. This may be a zero iteration loop. */
4168        for (i = XXH3_NEON_LANES; i < XXH_ACC_NB; i++) {
4169            XXH3_scalarScrambleRound(acc, secret, i);
4170        }
4171    }
4172}
4173
4174#endif
4175
4176#if (XXH_VECTOR == XXH_VSX)
4177
4178XXH_FORCE_INLINE void
4179XXH3_accumulate_512_vsx(  void* XXH_RESTRICT acc,
4180                    const void* XXH_RESTRICT input,
4181                    const void* XXH_RESTRICT secret)
4182{
4183    /* presumed aligned */
4184    unsigned int* const xacc = (unsigned int*) acc;
4185    xxh_u64x2 const* const xinput   = (xxh_u64x2 const*) input;   /* no alignment restriction */
4186    xxh_u64x2 const* const xsecret  = (xxh_u64x2 const*) secret;    /* no alignment restriction */
4187    xxh_u64x2 const v32 = { 32, 32 };
4188    size_t i;
4189    for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
4190        /* data_vec = xinput[i]; */
4191        xxh_u64x2 const data_vec = XXH_vec_loadu(xinput + i);
4192        /* key_vec = xsecret[i]; */
4193        xxh_u64x2 const key_vec  = XXH_vec_loadu(xsecret + i);
4194        xxh_u64x2 const data_key = data_vec ^ key_vec;
4195        /* shuffled = (data_key << 32) | (data_key >> 32); */
4196        xxh_u32x4 const shuffled = (xxh_u32x4)vec_rl(data_key, v32);
4197        /* product = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)shuffled & 0xFFFFFFFF); */
4198        xxh_u64x2 const product  = XXH_vec_mulo((xxh_u32x4)data_key, shuffled);
4199        /* acc_vec = xacc[i]; */
4200        xxh_u64x2 acc_vec        = (xxh_u64x2)vec_xl(0, xacc + 4 * i);
4201        acc_vec += product;
4202
4203        /* swap high and low halves */
4204#ifdef __s390x__
4205        acc_vec += vec_permi(data_vec, data_vec, 2);
4206#else
4207        acc_vec += vec_xxpermdi(data_vec, data_vec, 2);
4208#endif
4209        /* xacc[i] = acc_vec; */
4210        vec_xst((xxh_u32x4)acc_vec, 0, xacc + 4 * i);
4211    }
4212}
4213
4214XXH_FORCE_INLINE void
4215XXH3_scrambleAcc_vsx(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
4216{
4217    XXH_ASSERT((((size_t)acc) & 15) == 0);
4218
4219    {         xxh_u64x2* const xacc    =       (xxh_u64x2*) acc;
4220        const xxh_u64x2* const xsecret = (const xxh_u64x2*) secret;
4221        /* constants */
4222        xxh_u64x2 const v32  = { 32, 32 };
4223        xxh_u64x2 const v47 = { 47, 47 };
4224        xxh_u32x4 const prime = { XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1 };
4225        size_t i;
4226        for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
4227            /* xacc[i] ^= (xacc[i] >> 47); */
4228            xxh_u64x2 const acc_vec  = xacc[i];
4229            xxh_u64x2 const data_vec = acc_vec ^ (acc_vec >> v47);
4230
4231            /* xacc[i] ^= xsecret[i]; */
4232            xxh_u64x2 const key_vec  = XXH_vec_loadu(xsecret + i);
4233            xxh_u64x2 const data_key = data_vec ^ key_vec;
4234
4235            /* xacc[i] *= XXH_PRIME32_1 */
4236            /* prod_lo = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)prime & 0xFFFFFFFF);  */
4237            xxh_u64x2 const prod_even  = XXH_vec_mule((xxh_u32x4)data_key, prime);
4238            /* prod_hi = ((xxh_u64x2)data_key >> 32) * ((xxh_u64x2)prime >> 32);  */
4239            xxh_u64x2 const prod_odd  = XXH_vec_mulo((xxh_u32x4)data_key, prime);
4240            xacc[i] = prod_odd + (prod_even << v32);
4241    }   }
4242}
4243
4244#endif
4245
4246/* scalar variants - universal */
4247
4248/*!
4249 * @internal
4250 * @brief Scalar round for @ref XXH3_accumulate_512_scalar().
4251 *
4252 * This is extracted to its own function because the NEON path uses a combination
4253 * of NEON and scalar.
4254 */
4255XXH_FORCE_INLINE void
4256XXH3_scalarRound(void* XXH_RESTRICT acc,
4257                 void const* XXH_RESTRICT input,
4258                 void const* XXH_RESTRICT secret,
4259                 size_t lane)
4260{
4261    xxh_u64* xacc = (xxh_u64*) acc;
4262    xxh_u8 const* xinput  = (xxh_u8 const*) input;
4263    xxh_u8 const* xsecret = (xxh_u8 const*) secret;
4264    XXH_ASSERT(lane < XXH_ACC_NB);
4265    XXH_ASSERT(((size_t)acc & (XXH_ACC_ALIGN-1)) == 0);
4266    {
4267        xxh_u64 const data_val = XXH_readLE64(xinput + lane * 8);
4268        xxh_u64 const data_key = data_val ^ XXH_readLE64(xsecret + lane * 8);
4269        xacc[lane ^ 1] += data_val; /* swap adjacent lanes */
4270        xacc[lane] += XXH_mult32to64(data_key & 0xFFFFFFFF, data_key >> 32);
4271    }
4272}
4273
4274/*!
4275 * @internal
4276 * @brief Processes a 64 byte block of data using the scalar path.
4277 */
4278XXH_FORCE_INLINE void
4279XXH3_accumulate_512_scalar(void* XXH_RESTRICT acc,
4280                     const void* XXH_RESTRICT input,
4281                     const void* XXH_RESTRICT secret)
4282{
4283    size_t i;
4284    for (i=0; i < XXH_ACC_NB; i++) {
4285        XXH3_scalarRound(acc, input, secret, i);
4286    }
4287}
4288
4289/*!
4290 * @internal
4291 * @brief Scalar scramble step for @ref XXH3_scrambleAcc_scalar().
4292 *
4293 * This is extracted to its own function because the NEON path uses a combination
4294 * of NEON and scalar.
4295 */
4296XXH_FORCE_INLINE void
4297XXH3_scalarScrambleRound(void* XXH_RESTRICT acc,
4298                         void const* XXH_RESTRICT secret,
4299                         size_t lane)
4300{
4301    xxh_u64* const xacc = (xxh_u64*) acc;   /* presumed aligned */
4302    const xxh_u8* const xsecret = (const xxh_u8*) secret;   /* no alignment restriction */
4303    XXH_ASSERT((((size_t)acc) & (XXH_ACC_ALIGN-1)) == 0);
4304    XXH_ASSERT(lane < XXH_ACC_NB);
4305    {
4306        xxh_u64 const key64 = XXH_readLE64(xsecret + lane * 8);
4307        xxh_u64 acc64 = xacc[lane];
4308        acc64 = XXH_xorshift64(acc64, 47);
4309        acc64 ^= key64;
4310        acc64 *= XXH_PRIME32_1;
4311        xacc[lane] = acc64;
4312    }
4313}
4314
4315/*!
4316 * @internal
4317 * @brief Scrambles the accumulators after a large chunk has been read
4318 */
4319XXH_FORCE_INLINE void
4320XXH3_scrambleAcc_scalar(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
4321{
4322    size_t i;
4323    for (i=0; i < XXH_ACC_NB; i++) {
4324        XXH3_scalarScrambleRound(acc, secret, i);
4325    }
4326}
4327
4328XXH_FORCE_INLINE void
4329XXH3_initCustomSecret_scalar(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
4330{
4331    /*
4332     * We need a separate pointer for the hack below,
4333     * which requires a non-const pointer.
4334     * Any decent compiler will optimize this out otherwise.
4335     */
4336    const xxh_u8* kSecretPtr = XXH3_kSecret;
4337    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
4338
4339#if defined(__clang__) && defined(__aarch64__)
4340    /*
4341     * UGLY HACK:
4342     * Clang generates a bunch of MOV/MOVK pairs for aarch64, and they are
4343     * placed sequentially, in order, at the top of the unrolled loop.
4344     *
4345     * While MOVK is great for generating constants (2 cycles for a 64-bit
4346     * constant compared to 4 cycles for LDR), it fights for bandwidth with
4347     * the arithmetic instructions.
4348     *
4349     *   I   L   S
4350     * MOVK
4351     * MOVK
4352     * MOVK
4353     * MOVK
4354     * ADD
4355     * SUB      STR
4356     *          STR
4357     * By forcing loads from memory (as the asm line causes Clang to assume
4358     * that XXH3_kSecretPtr has been changed), the pipelines are used more
4359     * efficiently:
4360     *   I   L   S
4361     *      LDR
4362     *  ADD LDR
4363     *  SUB     STR
4364     *          STR
4365     *
4366     * See XXH3_NEON_LANES for details on the pipsline.
4367     *
4368     * XXH3_64bits_withSeed, len == 256, Snapdragon 835
4369     *   without hack: 2654.4 MB/s
4370     *   with hack:    3202.9 MB/s
4371     */
4372    XXH_COMPILER_GUARD(kSecretPtr);
4373#endif
4374    /*
4375     * Note: in debug mode, this overrides the asm optimization
4376     * and Clang will emit MOVK chains again.
4377     */
4378    XXH_ASSERT(kSecretPtr == XXH3_kSecret);
4379
4380    {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / 16;
4381        int i;
4382        for (i=0; i < nbRounds; i++) {
4383            /*
4384             * The asm hack causes Clang to assume that kSecretPtr aliases with
4385             * customSecret, and on aarch64, this prevented LDP from merging two
4386             * loads together for free. Putting the loads together before the stores
4387             * properly generates LDP.
4388             */
4389            xxh_u64 lo = XXH_readLE64(kSecretPtr + 16*i)     + seed64;
4390            xxh_u64 hi = XXH_readLE64(kSecretPtr + 16*i + 8) - seed64;
4391            XXH_writeLE64((xxh_u8*)customSecret + 16*i,     lo);
4392            XXH_writeLE64((xxh_u8*)customSecret + 16*i + 8, hi);
4393    }   }
4394}
4395
4396
4397typedef void (*XXH3_f_accumulate_512)(void* XXH_RESTRICT, const void*, const void*);
4398typedef void (*XXH3_f_scrambleAcc)(void* XXH_RESTRICT, const void*);
4399typedef void (*XXH3_f_initCustomSecret)(void* XXH_RESTRICT, xxh_u64);
4400
4401
4402#if (XXH_VECTOR == XXH_AVX512)
4403
4404#define XXH3_accumulate_512 XXH3_accumulate_512_avx512
4405#define XXH3_scrambleAcc    XXH3_scrambleAcc_avx512
4406#define XXH3_initCustomSecret XXH3_initCustomSecret_avx512
4407
4408#elif (XXH_VECTOR == XXH_AVX2)
4409
4410#define XXH3_accumulate_512 XXH3_accumulate_512_avx2
4411#define XXH3_scrambleAcc    XXH3_scrambleAcc_avx2
4412#define XXH3_initCustomSecret XXH3_initCustomSecret_avx2
4413
4414#elif (XXH_VECTOR == XXH_SSE2)
4415
4416#define XXH3_accumulate_512 XXH3_accumulate_512_sse2
4417#define XXH3_scrambleAcc    XXH3_scrambleAcc_sse2
4418#define XXH3_initCustomSecret XXH3_initCustomSecret_sse2
4419
4420#elif (XXH_VECTOR == XXH_NEON)
4421
4422#define XXH3_accumulate_512 XXH3_accumulate_512_neon
4423#define XXH3_scrambleAcc    XXH3_scrambleAcc_neon
4424#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
4425
4426#elif (XXH_VECTOR == XXH_VSX)
4427
4428#define XXH3_accumulate_512 XXH3_accumulate_512_vsx
4429#define XXH3_scrambleAcc    XXH3_scrambleAcc_vsx
4430#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
4431
4432#else /* scalar */
4433
4434#define XXH3_accumulate_512 XXH3_accumulate_512_scalar
4435#define XXH3_scrambleAcc    XXH3_scrambleAcc_scalar
4436#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
4437
4438#endif
4439
4440
4441
4442#ifndef XXH_PREFETCH_DIST
4443#  ifdef __clang__
4444#    define XXH_PREFETCH_DIST 320
4445#  else
4446#    if (XXH_VECTOR == XXH_AVX512)
4447#      define XXH_PREFETCH_DIST 512
4448#    else
4449#      define XXH_PREFETCH_DIST 384
4450#    endif
4451#  endif  /* __clang__ */
4452#endif  /* XXH_PREFETCH_DIST */
4453
4454/*
4455 * XXH3_accumulate()
4456 * Loops over XXH3_accumulate_512().
4457 * Assumption: nbStripes will not overflow the secret size
4458 */
4459XXH_FORCE_INLINE void
4460XXH3_accumulate(     xxh_u64* XXH_RESTRICT acc,
4461                const xxh_u8* XXH_RESTRICT input,
4462                const xxh_u8* XXH_RESTRICT secret,
4463                      size_t nbStripes,
4464                      XXH3_f_accumulate_512 f_acc512)
4465{
4466    size_t n;
4467    for (n = 0; n < nbStripes; n++ ) {
4468        const xxh_u8* const in = input + n*XXH_STRIPE_LEN;
4469        XXH_PREFETCH(in + XXH_PREFETCH_DIST);
4470        f_acc512(acc,
4471                 in,
4472                 secret + n*XXH_SECRET_CONSUME_RATE);
4473    }
4474}
4475
4476XXH_FORCE_INLINE void
4477XXH3_hashLong_internal_loop(xxh_u64* XXH_RESTRICT acc,
4478                      const xxh_u8* XXH_RESTRICT input, size_t len,
4479                      const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
4480                            XXH3_f_accumulate_512 f_acc512,
4481                            XXH3_f_scrambleAcc f_scramble)
4482{
4483    size_t const nbStripesPerBlock = (secretSize - XXH_STRIPE_LEN) / XXH_SECRET_CONSUME_RATE;
4484    size_t const block_len = XXH_STRIPE_LEN * nbStripesPerBlock;
4485    size_t const nb_blocks = (len - 1) / block_len;
4486
4487    size_t n;
4488
4489    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
4490
4491    for (n = 0; n < nb_blocks; n++) {
4492        XXH3_accumulate(acc, input + n*block_len, secret, nbStripesPerBlock, f_acc512);
4493        f_scramble(acc, secret + secretSize - XXH_STRIPE_LEN);
4494    }
4495
4496    /* last partial block */
4497    XXH_ASSERT(len > XXH_STRIPE_LEN);
4498    {   size_t const nbStripes = ((len - 1) - (block_len * nb_blocks)) / XXH_STRIPE_LEN;
4499        XXH_ASSERT(nbStripes <= (secretSize / XXH_SECRET_CONSUME_RATE));
4500        XXH3_accumulate(acc, input + nb_blocks*block_len, secret, nbStripes, f_acc512);
4501
4502        /* last stripe */
4503        {   const xxh_u8* const p = input + len - XXH_STRIPE_LEN;
4504#define XXH_SECRET_LASTACC_START 7  /* not aligned on 8, last secret is different from acc & scrambler */
4505            f_acc512(acc, p, secret + secretSize - XXH_STRIPE_LEN - XXH_SECRET_LASTACC_START);
4506    }   }
4507}
4508
4509XXH_FORCE_INLINE xxh_u64
4510XXH3_mix2Accs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret)
4511{
4512    return XXH3_mul128_fold64(
4513               acc[0] ^ XXH_readLE64(secret),
4514               acc[1] ^ XXH_readLE64(secret+8) );
4515}
4516
4517static XXH64_hash_t
4518XXH3_mergeAccs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret, xxh_u64 start)
4519{
4520    xxh_u64 result64 = start;
4521    size_t i = 0;
4522
4523    for (i = 0; i < 4; i++) {
4524        result64 += XXH3_mix2Accs(acc+2*i, secret + 16*i);
4525#if defined(__clang__)                                /* Clang */ \
4526    && (defined(__arm__) || defined(__thumb__))       /* ARMv7 */ \
4527    && (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */  \
4528    && !defined(XXH_ENABLE_AUTOVECTORIZE)             /* Define to disable */
4529        /*
4530         * UGLY HACK:
4531         * Prevent autovectorization on Clang ARMv7-a. Exact same problem as
4532         * the one in XXH3_len_129to240_64b. Speeds up shorter keys > 240b.
4533         * XXH3_64bits, len == 256, Snapdragon 835:
4534         *   without hack: 2063.7 MB/s
4535         *   with hack:    2560.7 MB/s
4536         */
4537        XXH_COMPILER_GUARD(result64);
4538#endif
4539    }
4540
4541    return XXH3_avalanche(result64);
4542}
4543
4544#define XXH3_INIT_ACC { XXH_PRIME32_3, XXH_PRIME64_1, XXH_PRIME64_2, XXH_PRIME64_3, \
4545                        XXH_PRIME64_4, XXH_PRIME32_2, XXH_PRIME64_5, XXH_PRIME32_1 }
4546
4547XXH_FORCE_INLINE XXH64_hash_t
4548XXH3_hashLong_64b_internal(const void* XXH_RESTRICT input, size_t len,
4549                           const void* XXH_RESTRICT secret, size_t secretSize,
4550                           XXH3_f_accumulate_512 f_acc512,
4551                           XXH3_f_scrambleAcc f_scramble)
4552{
4553    XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;
4554
4555    XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, f_acc512, f_scramble);
4556
4557    /* converge into final hash */
4558    XXH_STATIC_ASSERT(sizeof(acc) == 64);
4559    /* do not align on 8, so that the secret is different from the accumulator */
4560#define XXH_SECRET_MERGEACCS_START 11
4561    XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
4562    return XXH3_mergeAccs(acc, (const xxh_u8*)secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)len * XXH_PRIME64_1);
4563}
4564
4565/*
4566 * It's important for performance to transmit secret's size (when it's static)
4567 * so that the compiler can properly optimize the vectorized loop.
4568 * This makes a big performance difference for "medium" keys (<1 KB) when using AVX instruction set.
4569 */
4570XXH_FORCE_INLINE XXH64_hash_t
4571XXH3_hashLong_64b_withSecret(const void* XXH_RESTRICT input, size_t len,
4572                             XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
4573{
4574    (void)seed64;
4575    return XXH3_hashLong_64b_internal(input, len, secret, secretLen, XXH3_accumulate_512, XXH3_scrambleAcc);
4576}
4577
4578/*
4579 * It's preferable for performance that XXH3_hashLong is not inlined,
4580 * as it results in a smaller function for small data, easier to the instruction cache.
4581 * Note that inside this no_inline function, we do inline the internal loop,
4582 * and provide a statically defined secret size to allow optimization of vector loop.
4583 */
4584XXH_NO_INLINE XXH64_hash_t
4585XXH3_hashLong_64b_default(const void* XXH_RESTRICT input, size_t len,
4586                          XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
4587{
4588    (void)seed64; (void)secret; (void)secretLen;
4589    return XXH3_hashLong_64b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_accumulate_512, XXH3_scrambleAcc);
4590}
4591
4592/*
4593 * XXH3_hashLong_64b_withSeed():
4594 * Generate a custom key based on alteration of default XXH3_kSecret with the seed,
4595 * and then use this key for long mode hashing.
4596 *
4597 * This operation is decently fast but nonetheless costs a little bit of time.
4598 * Try to avoid it whenever possible (typically when seed==0).
4599 *
4600 * It's important for performance that XXH3_hashLong is not inlined. Not sure
4601 * why (uop cache maybe?), but the difference is large and easily measurable.
4602 */
4603XXH_FORCE_INLINE XXH64_hash_t
4604XXH3_hashLong_64b_withSeed_internal(const void* input, size_t len,
4605                                    XXH64_hash_t seed,
4606                                    XXH3_f_accumulate_512 f_acc512,
4607                                    XXH3_f_scrambleAcc f_scramble,
4608                                    XXH3_f_initCustomSecret f_initSec)
4609{
4610    if (seed == 0)
4611        return XXH3_hashLong_64b_internal(input, len,
4612                                          XXH3_kSecret, sizeof(XXH3_kSecret),
4613                                          f_acc512, f_scramble);
4614    {   XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
4615        f_initSec(secret, seed);
4616        return XXH3_hashLong_64b_internal(input, len, secret, sizeof(secret),
4617                                          f_acc512, f_scramble);
4618    }
4619}
4620
4621/*
4622 * It's important for performance that XXH3_hashLong is not inlined.
4623 */
4624XXH_NO_INLINE XXH64_hash_t
4625XXH3_hashLong_64b_withSeed(const void* input, size_t len,
4626                           XXH64_hash_t seed, const xxh_u8* secret, size_t secretLen)
4627{
4628    (void)secret; (void)secretLen;
4629    return XXH3_hashLong_64b_withSeed_internal(input, len, seed,
4630                XXH3_accumulate_512, XXH3_scrambleAcc, XXH3_initCustomSecret);
4631}
4632
4633
4634typedef XXH64_hash_t (*XXH3_hashLong64_f)(const void* XXH_RESTRICT, size_t,
4635                                          XXH64_hash_t, const xxh_u8* XXH_RESTRICT, size_t);
4636
4637XXH_FORCE_INLINE XXH64_hash_t
4638XXH3_64bits_internal(const void* XXH_RESTRICT input, size_t len,
4639                     XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
4640                     XXH3_hashLong64_f f_hashLong)
4641{
4642    XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
4643    /*
4644     * If an action is to be taken if `secretLen` condition is not respected,
4645     * it should be done here.
4646     * For now, it's a contract pre-condition.
4647     * Adding a check and a branch here would cost performance at every hash.
4648     * Also, note that function signature doesn't offer room to return an error.
4649     */
4650    if (len <= 16)
4651        return XXH3_len_0to16_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
4652    if (len <= 128)
4653        return XXH3_len_17to128_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
4654    if (len <= XXH3_MIDSIZE_MAX)
4655        return XXH3_len_129to240_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
4656    return f_hashLong(input, len, seed64, (const xxh_u8*)secret, secretLen);
4657}
4658
4659
4660/* ===   Public entry point   === */
4661
4662/*! @ingroup xxh3_family */
4663XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(const void* input, size_t len)
4664{
4665    return XXH3_64bits_internal(input, len, 0, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_default);
4666}
4667
4668/*! @ingroup xxh3_family */
4669XXH_PUBLIC_API XXH64_hash_t
4670XXH3_64bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
4671{
4672    return XXH3_64bits_internal(input, len, 0, secret, secretSize, XXH3_hashLong_64b_withSecret);
4673}
4674
4675/*! @ingroup xxh3_family */
4676XXH_PUBLIC_API XXH64_hash_t
4677XXH3_64bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
4678{
4679    return XXH3_64bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_withSeed);
4680}
4681
4682XXH_PUBLIC_API XXH64_hash_t
4683XXH3_64bits_withSecretandSeed(const void* input, size_t len, const void* secret, size_t secretSize, XXH64_hash_t seed)
4684{
4685    if (len <= XXH3_MIDSIZE_MAX)
4686        return XXH3_64bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), NULL);
4687    return XXH3_hashLong_64b_withSecret(input, len, seed, (const xxh_u8*)secret, secretSize);
4688}
4689
4690
4691/* ===   XXH3 streaming   === */
4692
4693/*
4694 * Malloc's a pointer that is always aligned to align.
4695 *
4696 * This must be freed with `XXH_alignedFree()`.
4697 *
4698 * malloc typically guarantees 16 byte alignment on 64-bit systems and 8 byte
4699 * alignment on 32-bit. This isn't enough for the 32 byte aligned loads in AVX2
4700 * or on 32-bit, the 16 byte aligned loads in SSE2 and NEON.
4701 *
4702 * This underalignment previously caused a rather obvious crash which went
4703 * completely unnoticed due to XXH3_createState() not actually being tested.
4704 * Credit to RedSpah for noticing this bug.
4705 *
4706 * The alignment is done manually: Functions like posix_memalign or _mm_malloc
4707 * are avoided: To maintain portability, we would have to write a fallback
4708 * like this anyways, and besides, testing for the existence of library
4709 * functions without relying on external build tools is impossible.
4710 *
4711 * The method is simple: Overallocate, manually align, and store the offset
4712 * to the original behind the returned pointer.
4713 *
4714 * Align must be a power of 2 and 8 <= align <= 128.
4715 */
4716static void* XXH_alignedMalloc(size_t s, size_t align)
4717{
4718    XXH_ASSERT(align <= 128 && align >= 8); /* range check */
4719    XXH_ASSERT((align & (align-1)) == 0);   /* power of 2 */
4720    XXH_ASSERT(s != 0 && s < (s + align));  /* empty/overflow */
4721    {   /* Overallocate to make room for manual realignment and an offset byte */
4722        xxh_u8* base = (xxh_u8*)XXH_malloc(s + align);
4723        if (base != NULL) {
4724            /*
4725             * Get the offset needed to align this pointer.
4726             *
4727             * Even if the returned pointer is aligned, there will always be
4728             * at least one byte to store the offset to the original pointer.
4729             */
4730            size_t offset = align - ((size_t)base & (align - 1)); /* base % align */
4731            /* Add the offset for the now-aligned pointer */
4732            xxh_u8* ptr = base + offset;
4733
4734            XXH_ASSERT((size_t)ptr % align == 0);
4735
4736            /* Store the offset immediately before the returned pointer. */
4737            ptr[-1] = (xxh_u8)offset;
4738            return ptr;
4739        }
4740        return NULL;
4741    }
4742}
4743/*
4744 * Frees an aligned pointer allocated by XXH_alignedMalloc(). Don't pass
4745 * normal malloc'd pointers, XXH_alignedMalloc has a specific data layout.
4746 */
4747static void XXH_alignedFree(void* p)
4748{
4749    if (p != NULL) {
4750        xxh_u8* ptr = (xxh_u8*)p;
4751        /* Get the offset byte we added in XXH_malloc. */
4752        xxh_u8 offset = ptr[-1];
4753        /* Free the original malloc'd pointer */
4754        xxh_u8* base = ptr - offset;
4755        XXH_free(base);
4756    }
4757}
4758/*! @ingroup xxh3_family */
4759XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void)
4760{
4761    XXH3_state_t* const state = (XXH3_state_t*)XXH_alignedMalloc(sizeof(XXH3_state_t), 64);
4762    if (state==NULL) return NULL;
4763    XXH3_INITSTATE(state);
4764    return state;
4765}
4766
4767/*! @ingroup xxh3_family */
4768XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr)
4769{
4770    XXH_alignedFree(statePtr);
4771    return XXH_OK;
4772}
4773
4774/*! @ingroup xxh3_family */
4775XXH_PUBLIC_API void
4776XXH3_copyState(XXH3_state_t* dst_state, const XXH3_state_t* src_state)
4777{
4778    XXH_memcpy(dst_state, src_state, sizeof(*dst_state));
4779}
4780
4781static void
4782XXH3_reset_internal(XXH3_state_t* statePtr,
4783                    XXH64_hash_t seed,
4784                    const void* secret, size_t secretSize)
4785{
4786    size_t const initStart = offsetof(XXH3_state_t, bufferedSize);
4787    size_t const initLength = offsetof(XXH3_state_t, nbStripesPerBlock) - initStart;
4788    XXH_ASSERT(offsetof(XXH3_state_t, nbStripesPerBlock) > initStart);
4789    XXH_ASSERT(statePtr != NULL);
4790    /* set members from bufferedSize to nbStripesPerBlock (excluded) to 0 */
4791    memset((char*)statePtr + initStart, 0, initLength);
4792    statePtr->acc[0] = XXH_PRIME32_3;
4793    statePtr->acc[1] = XXH_PRIME64_1;
4794    statePtr->acc[2] = XXH_PRIME64_2;
4795    statePtr->acc[3] = XXH_PRIME64_3;
4796    statePtr->acc[4] = XXH_PRIME64_4;
4797    statePtr->acc[5] = XXH_PRIME32_2;
4798    statePtr->acc[6] = XXH_PRIME64_5;
4799    statePtr->acc[7] = XXH_PRIME32_1;
4800    statePtr->seed = seed;
4801    statePtr->useSeed = (seed != 0);
4802    statePtr->extSecret = (const unsigned char*)secret;
4803    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
4804    statePtr->secretLimit = secretSize - XXH_STRIPE_LEN;
4805    statePtr->nbStripesPerBlock = statePtr->secretLimit / XXH_SECRET_CONSUME_RATE;
4806}
4807
4808/*! @ingroup xxh3_family */
4809XXH_PUBLIC_API XXH_errorcode
4810XXH3_64bits_reset(XXH3_state_t* statePtr)
4811{
4812    if (statePtr == NULL) return XXH_ERROR;
4813    XXH3_reset_internal(statePtr, 0, XXH3_kSecret, XXH_SECRET_DEFAULT_SIZE);
4814    return XXH_OK;
4815}
4816
4817/*! @ingroup xxh3_family */
4818XXH_PUBLIC_API XXH_errorcode
4819XXH3_64bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
4820{
4821    if (statePtr == NULL) return XXH_ERROR;
4822    XXH3_reset_internal(statePtr, 0, secret, secretSize);
4823    if (secret == NULL) return XXH_ERROR;
4824    if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
4825    return XXH_OK;
4826}
4827
4828/*! @ingroup xxh3_family */
4829XXH_PUBLIC_API XXH_errorcode
4830XXH3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
4831{
4832    if (statePtr == NULL) return XXH_ERROR;
4833    if (seed==0) return XXH3_64bits_reset(statePtr);
4834    if ((seed != statePtr->seed) || (statePtr->extSecret != NULL))
4835        XXH3_initCustomSecret(statePtr->customSecret, seed);
4836    XXH3_reset_internal(statePtr, seed, NULL, XXH_SECRET_DEFAULT_SIZE);
4837    return XXH_OK;
4838}
4839
4840/*! @ingroup xxh3_family */
4841XXH_PUBLIC_API XXH_errorcode
4842XXH3_64bits_reset_withSecretandSeed(XXH3_state_t* statePtr, const void* secret, size_t secretSize, XXH64_hash_t seed64)
4843{
4844    if (statePtr == NULL) return XXH_ERROR;
4845    if (secret == NULL) return XXH_ERROR;
4846    if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
4847    XXH3_reset_internal(statePtr, seed64, secret, secretSize);
4848    statePtr->useSeed = 1; /* always, even if seed64==0 */
4849    return XXH_OK;
4850}
4851
4852/* Note : when XXH3_consumeStripes() is invoked,
4853 * there must be a guarantee that at least one more byte must be consumed from input
4854 * so that the function can blindly consume all stripes using the "normal" secret segment */
4855XXH_FORCE_INLINE void
4856XXH3_consumeStripes(xxh_u64* XXH_RESTRICT acc,
4857                    size_t* XXH_RESTRICT nbStripesSoFarPtr, size_t nbStripesPerBlock,
4858                    const xxh_u8* XXH_RESTRICT input, size_t nbStripes,
4859                    const xxh_u8* XXH_RESTRICT secret, size_t secretLimit,
4860                    XXH3_f_accumulate_512 f_acc512,
4861                    XXH3_f_scrambleAcc f_scramble)
4862{
4863    XXH_ASSERT(nbStripes <= nbStripesPerBlock);  /* can handle max 1 scramble per invocation */
4864    XXH_ASSERT(*nbStripesSoFarPtr < nbStripesPerBlock);
4865    if (nbStripesPerBlock - *nbStripesSoFarPtr <= nbStripes) {
4866        /* need a scrambling operation */
4867        size_t const nbStripesToEndofBlock = nbStripesPerBlock - *nbStripesSoFarPtr;
4868        size_t const nbStripesAfterBlock = nbStripes - nbStripesToEndofBlock;
4869        XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, nbStripesToEndofBlock, f_acc512);
4870        f_scramble(acc, secret + secretLimit);
4871        XXH3_accumulate(acc, input + nbStripesToEndofBlock * XXH_STRIPE_LEN, secret, nbStripesAfterBlock, f_acc512);
4872        *nbStripesSoFarPtr = nbStripesAfterBlock;
4873    } else {
4874        XXH3_accumulate(acc, input, secret + nbStripesSoFarPtr[0] * XXH_SECRET_CONSUME_RATE, nbStripes, f_acc512);
4875        *nbStripesSoFarPtr += nbStripes;
4876    }
4877}
4878
4879#ifndef XXH3_STREAM_USE_STACK
4880# ifndef __clang__ /* clang doesn't need additional stack space */
4881#   define XXH3_STREAM_USE_STACK 1
4882# endif
4883#endif
4884/*
4885 * Both XXH3_64bits_update and XXH3_128bits_update use this routine.
4886 */
4887XXH_FORCE_INLINE XXH_errorcode
4888XXH3_update(XXH3_state_t* XXH_RESTRICT const state,
4889            const xxh_u8* XXH_RESTRICT input, size_t len,
4890            XXH3_f_accumulate_512 f_acc512,
4891            XXH3_f_scrambleAcc f_scramble)
4892{
4893    if (input==NULL) {
4894        XXH_ASSERT(len == 0);
4895        return XXH_OK;
4896    }
4897
4898    XXH_ASSERT(state != NULL);
4899    {   const xxh_u8* const bEnd = input + len;
4900        const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
4901#if defined(XXH3_STREAM_USE_STACK) && XXH3_STREAM_USE_STACK >= 1
4902        /* For some reason, gcc and MSVC seem to suffer greatly
4903         * when operating accumulators directly into state.
4904         * Operating into stack space seems to enable proper optimization.
4905         * clang, on the other hand, doesn't seem to need this trick */
4906        XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[8]; memcpy(acc, state->acc, sizeof(acc));
4907#else
4908        xxh_u64* XXH_RESTRICT const acc = state->acc;
4909#endif
4910        state->totalLen += len;
4911        XXH_ASSERT(state->bufferedSize <= XXH3_INTERNALBUFFER_SIZE);
4912
4913        /* small input : just fill in tmp buffer */
4914        if (state->bufferedSize + len <= XXH3_INTERNALBUFFER_SIZE) {
4915            XXH_memcpy(state->buffer + state->bufferedSize, input, len);
4916            state->bufferedSize += (XXH32_hash_t)len;
4917            return XXH_OK;
4918        }
4919
4920        /* total input is now > XXH3_INTERNALBUFFER_SIZE */
4921        #define XXH3_INTERNALBUFFER_STRIPES (XXH3_INTERNALBUFFER_SIZE / XXH_STRIPE_LEN)
4922        XXH_STATIC_ASSERT(XXH3_INTERNALBUFFER_SIZE % XXH_STRIPE_LEN == 0);   /* clean multiple */
4923
4924        /*
4925         * Internal buffer is partially filled (always, except at beginning)
4926         * Complete it, then consume it.
4927         */
4928        if (state->bufferedSize) {
4929            size_t const loadSize = XXH3_INTERNALBUFFER_SIZE - state->bufferedSize;
4930            XXH_memcpy(state->buffer + state->bufferedSize, input, loadSize);
4931            input += loadSize;
4932            XXH3_consumeStripes(acc,
4933                               &state->nbStripesSoFar, state->nbStripesPerBlock,
4934                                state->buffer, XXH3_INTERNALBUFFER_STRIPES,
4935                                secret, state->secretLimit,
4936                                f_acc512, f_scramble);
4937            state->bufferedSize = 0;
4938        }
4939        XXH_ASSERT(input < bEnd);
4940
4941        /* large input to consume : ingest per full block */
4942        if ((size_t)(bEnd - input) > state->nbStripesPerBlock * XXH_STRIPE_LEN) {
4943            size_t nbStripes = (size_t)(bEnd - 1 - input) / XXH_STRIPE_LEN;
4944            XXH_ASSERT(state->nbStripesPerBlock >= state->nbStripesSoFar);
4945            /* join to current block's end */
4946            {   size_t const nbStripesToEnd = state->nbStripesPerBlock - state->nbStripesSoFar;
4947                XXH_ASSERT(nbStripesToEnd <= nbStripes);
4948                XXH3_accumulate(acc, input, secret + state->nbStripesSoFar * XXH_SECRET_CONSUME_RATE, nbStripesToEnd, f_acc512);
4949                f_scramble(acc, secret + state->secretLimit);
4950                state->nbStripesSoFar = 0;
4951                input += nbStripesToEnd * XXH_STRIPE_LEN;
4952                nbStripes -= nbStripesToEnd;
4953            }
4954            /* consume per entire blocks */
4955            while(nbStripes >= state->nbStripesPerBlock) {
4956                XXH3_accumulate(acc, input, secret, state->nbStripesPerBlock, f_acc512);
4957                f_scramble(acc, secret + state->secretLimit);
4958                input += state->nbStripesPerBlock * XXH_STRIPE_LEN;
4959                nbStripes -= state->nbStripesPerBlock;
4960            }
4961            /* consume last partial block */
4962            XXH3_accumulate(acc, input, secret, nbStripes, f_acc512);
4963            input += nbStripes * XXH_STRIPE_LEN;
4964            XXH_ASSERT(input < bEnd);  /* at least some bytes left */
4965            state->nbStripesSoFar = nbStripes;
4966            /* buffer predecessor of last partial stripe */
4967            XXH_memcpy(state->buffer + sizeof(state->buffer) - XXH_STRIPE_LEN, input - XXH_STRIPE_LEN, XXH_STRIPE_LEN);
4968            XXH_ASSERT(bEnd - input <= XXH_STRIPE_LEN);
4969        } else {
4970            /* content to consume <= block size */
4971            /* Consume input by a multiple of internal buffer size */
4972            if (bEnd - input > XXH3_INTERNALBUFFER_SIZE) {
4973                const xxh_u8* const limit = bEnd - XXH3_INTERNALBUFFER_SIZE;
4974                do {
4975                    XXH3_consumeStripes(acc,
4976                                       &state->nbStripesSoFar, state->nbStripesPerBlock,
4977                                        input, XXH3_INTERNALBUFFER_STRIPES,
4978                                        secret, state->secretLimit,
4979                                        f_acc512, f_scramble);
4980                    input += XXH3_INTERNALBUFFER_SIZE;
4981                } while (input<limit);
4982                /* buffer predecessor of last partial stripe */
4983                XXH_memcpy(state->buffer + sizeof(state->buffer) - XXH_STRIPE_LEN, input - XXH_STRIPE_LEN, XXH_STRIPE_LEN);
4984            }
4985        }
4986
4987        /* Some remaining input (always) : buffer it */
4988        XXH_ASSERT(input < bEnd);
4989        XXH_ASSERT(bEnd - input <= XXH3_INTERNALBUFFER_SIZE);
4990        XXH_ASSERT(state->bufferedSize == 0);
4991        XXH_memcpy(state->buffer, input, (size_t)(bEnd-input));
4992        state->bufferedSize = (XXH32_hash_t)(bEnd-input);
4993#if defined(XXH3_STREAM_USE_STACK) && XXH3_STREAM_USE_STACK >= 1
4994        /* save stack accumulators into state */
4995        memcpy(state->acc, acc, sizeof(acc));
4996#endif
4997    }
4998
4999    return XXH_OK;
5000}
5001
5002/*! @ingroup xxh3_family */
5003XXH_PUBLIC_API XXH_errorcode
5004XXH3_64bits_update(XXH3_state_t* state, const void* input, size_t len)
5005{
5006    return XXH3_update(state, (const xxh_u8*)input, len,
5007                       XXH3_accumulate_512, XXH3_scrambleAcc);
5008}
5009
5010
5011XXH_FORCE_INLINE void
5012XXH3_digest_long (XXH64_hash_t* acc,
5013                  const XXH3_state_t* state,
5014                  const unsigned char* secret)
5015{
5016    /*
5017     * Digest on a local copy. This way, the state remains unaltered, and it can
5018     * continue ingesting more input afterwards.
5019     */
5020    XXH_memcpy(acc, state->acc, sizeof(state->acc));
5021    if (state->bufferedSize >= XXH_STRIPE_LEN) {
5022        size_t const nbStripes = (state->bufferedSize - 1) / XXH_STRIPE_LEN;
5023        size_t nbStripesSoFar = state->nbStripesSoFar;
5024        XXH3_consumeStripes(acc,
5025                           &nbStripesSoFar, state->nbStripesPerBlock,
5026                            state->buffer, nbStripes,
5027                            secret, state->secretLimit,
5028                            XXH3_accumulate_512, XXH3_scrambleAcc);
5029        /* last stripe */
5030        XXH3_accumulate_512(acc,
5031                            state->buffer + state->bufferedSize - XXH_STRIPE_LEN,
5032                            secret + state->secretLimit - XXH_SECRET_LASTACC_START);
5033    } else {  /* bufferedSize < XXH_STRIPE_LEN */
5034        xxh_u8 lastStripe[XXH_STRIPE_LEN];
5035        size_t const catchupSize = XXH_STRIPE_LEN - state->bufferedSize;
5036        XXH_ASSERT(state->bufferedSize > 0);  /* there is always some input buffered */
5037        XXH_memcpy(lastStripe, state->buffer + sizeof(state->buffer) - catchupSize, catchupSize);
5038        XXH_memcpy(lastStripe + catchupSize, state->buffer, state->bufferedSize);
5039        XXH3_accumulate_512(acc,
5040                            lastStripe,
5041                            secret + state->secretLimit - XXH_SECRET_LASTACC_START);
5042    }
5043}
5044
5045/*! @ingroup xxh3_family */
5046XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_digest (const XXH3_state_t* state)
5047{
5048    const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
5049    if (state->totalLen > XXH3_MIDSIZE_MAX) {
5050        XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
5051        XXH3_digest_long(acc, state, secret);
5052        return XXH3_mergeAccs(acc,
5053                              secret + XXH_SECRET_MERGEACCS_START,
5054                              (xxh_u64)state->totalLen * XXH_PRIME64_1);
5055    }
5056    /* totalLen <= XXH3_MIDSIZE_MAX: digesting a short input */
5057    if (state->useSeed)
5058        return XXH3_64bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
5059    return XXH3_64bits_withSecret(state->buffer, (size_t)(state->totalLen),
5060                                  secret, state->secretLimit + XXH_STRIPE_LEN);
5061}
5062
5063
5064
5065/* ==========================================
5066 * XXH3 128 bits (a.k.a XXH128)
5067 * ==========================================
5068 * XXH3's 128-bit variant has better mixing and strength than the 64-bit variant,
5069 * even without counting the significantly larger output size.
5070 *
5071 * For example, extra steps are taken to avoid the seed-dependent collisions
5072 * in 17-240 byte inputs (See XXH3_mix16B and XXH128_mix32B).
5073 *
5074 * This strength naturally comes at the cost of some speed, especially on short
5075 * lengths. Note that longer hashes are about as fast as the 64-bit version
5076 * due to it using only a slight modification of the 64-bit loop.
5077 *
5078 * XXH128 is also more oriented towards 64-bit machines. It is still extremely
5079 * fast for a _128-bit_ hash on 32-bit (it usually clears XXH64).
5080 */
5081
5082XXH_FORCE_INLINE XXH128_hash_t
5083XXH3_len_1to3_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5084{
5085    /* A doubled version of 1to3_64b with different constants. */
5086    XXH_ASSERT(input != NULL);
5087    XXH_ASSERT(1 <= len && len <= 3);
5088    XXH_ASSERT(secret != NULL);
5089    /*
5090     * len = 1: combinedl = { input[0], 0x01, input[0], input[0] }
5091     * len = 2: combinedl = { input[1], 0x02, input[0], input[1] }
5092     * len = 3: combinedl = { input[2], 0x03, input[0], input[1] }
5093     */
5094    {   xxh_u8 const c1 = input[0];
5095        xxh_u8 const c2 = input[len >> 1];
5096        xxh_u8 const c3 = input[len - 1];
5097        xxh_u32 const combinedl = ((xxh_u32)c1 <<16) | ((xxh_u32)c2 << 24)
5098                                | ((xxh_u32)c3 << 0) | ((xxh_u32)len << 8);
5099        xxh_u32 const combinedh = XXH_rotl32(XXH_swap32(combinedl), 13);
5100        xxh_u64 const bitflipl = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
5101        xxh_u64 const bitfliph = (XXH_readLE32(secret+8) ^ XXH_readLE32(secret+12)) - seed;
5102        xxh_u64 const keyed_lo = (xxh_u64)combinedl ^ bitflipl;
5103        xxh_u64 const keyed_hi = (xxh_u64)combinedh ^ bitfliph;
5104        XXH128_hash_t h128;
5105        h128.low64  = XXH64_avalanche(keyed_lo);
5106        h128.high64 = XXH64_avalanche(keyed_hi);
5107        return h128;
5108    }
5109}
5110
5111XXH_FORCE_INLINE XXH128_hash_t
5112XXH3_len_4to8_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5113{
5114    XXH_ASSERT(input != NULL);
5115    XXH_ASSERT(secret != NULL);
5116    XXH_ASSERT(4 <= len && len <= 8);
5117    seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
5118    {   xxh_u32 const input_lo = XXH_readLE32(input);
5119        xxh_u32 const input_hi = XXH_readLE32(input + len - 4);
5120        xxh_u64 const input_64 = input_lo + ((xxh_u64)input_hi << 32);
5121        xxh_u64 const bitflip = (XXH_readLE64(secret+16) ^ XXH_readLE64(secret+24)) + seed;
5122        xxh_u64 const keyed = input_64 ^ bitflip;
5123
5124        /* Shift len to the left to ensure it is even, this avoids even multiplies. */
5125        XXH128_hash_t m128 = XXH_mult64to128(keyed, XXH_PRIME64_1 + (len << 2));
5126
5127        m128.high64 += (m128.low64 << 1);
5128        m128.low64  ^= (m128.high64 >> 3);
5129
5130        m128.low64   = XXH_xorshift64(m128.low64, 35);
5131        m128.low64  *= 0x9FB21C651E98DF25ULL;
5132        m128.low64   = XXH_xorshift64(m128.low64, 28);
5133        m128.high64  = XXH3_avalanche(m128.high64);
5134        return m128;
5135    }
5136}
5137
5138XXH_FORCE_INLINE XXH128_hash_t
5139XXH3_len_9to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5140{
5141    XXH_ASSERT(input != NULL);
5142    XXH_ASSERT(secret != NULL);
5143    XXH_ASSERT(9 <= len && len <= 16);
5144    {   xxh_u64 const bitflipl = (XXH_readLE64(secret+32) ^ XXH_readLE64(secret+40)) - seed;
5145        xxh_u64 const bitfliph = (XXH_readLE64(secret+48) ^ XXH_readLE64(secret+56)) + seed;
5146        xxh_u64 const input_lo = XXH_readLE64(input);
5147        xxh_u64       input_hi = XXH_readLE64(input + len - 8);
5148        XXH128_hash_t m128 = XXH_mult64to128(input_lo ^ input_hi ^ bitflipl, XXH_PRIME64_1);
5149        /*
5150         * Put len in the middle of m128 to ensure that the length gets mixed to
5151         * both the low and high bits in the 128x64 multiply below.
5152         */
5153        m128.low64 += (xxh_u64)(len - 1) << 54;
5154        input_hi   ^= bitfliph;
5155        /*
5156         * Add the high 32 bits of input_hi to the high 32 bits of m128, then
5157         * add the long product of the low 32 bits of input_hi and XXH_PRIME32_2 to
5158         * the high 64 bits of m128.
5159         *
5160         * The best approach to this operation is different on 32-bit and 64-bit.
5161         */
5162        if (sizeof(void *) < sizeof(xxh_u64)) { /* 32-bit */
5163            /*
5164             * 32-bit optimized version, which is more readable.
5165             *
5166             * On 32-bit, it removes an ADC and delays a dependency between the two
5167             * halves of m128.high64, but it generates an extra mask on 64-bit.
5168             */
5169            m128.high64 += (input_hi & 0xFFFFFFFF00000000ULL) + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2);
5170        } else {
5171            /*
5172             * 64-bit optimized (albeit more confusing) version.
5173             *
5174             * Uses some properties of addition and multiplication to remove the mask:
5175             *
5176             * Let:
5177             *    a = input_hi.lo = (input_hi & 0x00000000FFFFFFFF)
5178             *    b = input_hi.hi = (input_hi & 0xFFFFFFFF00000000)
5179             *    c = XXH_PRIME32_2
5180             *
5181             *    a + (b * c)
5182             * Inverse Property: x + y - x == y
5183             *    a + (b * (1 + c - 1))
5184             * Distributive Property: x * (y + z) == (x * y) + (x * z)
5185             *    a + (b * 1) + (b * (c - 1))
5186             * Identity Property: x * 1 == x
5187             *    a + b + (b * (c - 1))
5188             *
5189             * Substitute a, b, and c:
5190             *    input_hi.hi + input_hi.lo + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
5191             *
5192             * Since input_hi.hi + input_hi.lo == input_hi, we get this:
5193             *    input_hi + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
5194             */
5195            m128.high64 += input_hi + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2 - 1);
5196        }
5197        /* m128 ^= XXH_swap64(m128 >> 64); */
5198        m128.low64  ^= XXH_swap64(m128.high64);
5199
5200        {   /* 128x64 multiply: h128 = m128 * XXH_PRIME64_2; */
5201            XXH128_hash_t h128 = XXH_mult64to128(m128.low64, XXH_PRIME64_2);
5202            h128.high64 += m128.high64 * XXH_PRIME64_2;
5203
5204            h128.low64   = XXH3_avalanche(h128.low64);
5205            h128.high64  = XXH3_avalanche(h128.high64);
5206            return h128;
5207    }   }
5208}
5209
5210/*
5211 * Assumption: `secret` size is >= XXH3_SECRET_SIZE_MIN
5212 */
5213XXH_FORCE_INLINE XXH128_hash_t
5214XXH3_len_0to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
5215{
5216    XXH_ASSERT(len <= 16);
5217    {   if (len > 8) return XXH3_len_9to16_128b(input, len, secret, seed);
5218        if (len >= 4) return XXH3_len_4to8_128b(input, len, secret, seed);
5219        if (len) return XXH3_len_1to3_128b(input, len, secret, seed);
5220        {   XXH128_hash_t h128;
5221            xxh_u64 const bitflipl = XXH_readLE64(secret+64) ^ XXH_readLE64(secret+72);
5222            xxh_u64 const bitfliph = XXH_readLE64(secret+80) ^ XXH_readLE64(secret+88);
5223            h128.low64 = XXH64_avalanche(seed ^ bitflipl);
5224            h128.high64 = XXH64_avalanche( seed ^ bitfliph);
5225            return h128;
5226    }   }
5227}
5228
5229/*
5230 * A bit slower than XXH3_mix16B, but handles multiply by zero better.
5231 */
5232XXH_FORCE_INLINE XXH128_hash_t
5233XXH128_mix32B(XXH128_hash_t acc, const xxh_u8* input_1, const xxh_u8* input_2,
5234              const xxh_u8* secret, XXH64_hash_t seed)
5235{
5236    acc.low64  += XXH3_mix16B (input_1, secret+0, seed);
5237    acc.low64  ^= XXH_readLE64(input_2) + XXH_readLE64(input_2 + 8);
5238    acc.high64 += XXH3_mix16B (input_2, secret+16, seed);
5239    acc.high64 ^= XXH_readLE64(input_1) + XXH_readLE64(input_1 + 8);
5240    return acc;
5241}
5242
5243
5244XXH_FORCE_INLINE XXH128_hash_t
5245XXH3_len_17to128_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
5246                      const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
5247                      XXH64_hash_t seed)
5248{
5249    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
5250    XXH_ASSERT(16 < len && len <= 128);
5251
5252    {   XXH128_hash_t acc;
5253        acc.low64 = len * XXH_PRIME64_1;
5254        acc.high64 = 0;
5255        if (len > 32) {
5256            if (len > 64) {
5257                if (len > 96) {
5258                    acc = XXH128_mix32B(acc, input+48, input+len-64, secret+96, seed);
5259                }
5260                acc = XXH128_mix32B(acc, input+32, input+len-48, secret+64, seed);
5261            }
5262            acc = XXH128_mix32B(acc, input+16, input+len-32, secret+32, seed);
5263        }
5264        acc = XXH128_mix32B(acc, input, input+len-16, secret, seed);
5265        {   XXH128_hash_t h128;
5266            h128.low64  = acc.low64 + acc.high64;
5267            h128.high64 = (acc.low64    * XXH_PRIME64_1)
5268                        + (acc.high64   * XXH_PRIME64_4)
5269                        + ((len - seed) * XXH_PRIME64_2);
5270            h128.low64  = XXH3_avalanche(h128.low64);
5271            h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
5272            return h128;
5273        }
5274    }
5275}
5276
5277XXH_NO_INLINE XXH128_hash_t
5278XXH3_len_129to240_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
5279                       const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
5280                       XXH64_hash_t seed)
5281{
5282    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
5283    XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
5284
5285    {   XXH128_hash_t acc;
5286        int const nbRounds = (int)len / 32;
5287        int i;
5288        acc.low64 = len * XXH_PRIME64_1;
5289        acc.high64 = 0;
5290        for (i=0; i<4; i++) {
5291            acc = XXH128_mix32B(acc,
5292                                input  + (32 * i),
5293                                input  + (32 * i) + 16,
5294                                secret + (32 * i),
5295                                seed);
5296        }
5297        acc.low64 = XXH3_avalanche(acc.low64);
5298        acc.high64 = XXH3_avalanche(acc.high64);
5299        XXH_ASSERT(nbRounds >= 4);
5300        for (i=4 ; i < nbRounds; i++) {
5301            acc = XXH128_mix32B(acc,
5302                                input + (32 * i),
5303                                input + (32 * i) + 16,
5304                                secret + XXH3_MIDSIZE_STARTOFFSET + (32 * (i - 4)),
5305                                seed);
5306        }
5307        /* last bytes */
5308        acc = XXH128_mix32B(acc,
5309                            input + len - 16,
5310                            input + len - 32,
5311                            secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET - 16,
5312                            0ULL - seed);
5313
5314        {   XXH128_hash_t h128;
5315            h128.low64  = acc.low64 + acc.high64;
5316            h128.high64 = (acc.low64    * XXH_PRIME64_1)
5317                        + (acc.high64   * XXH_PRIME64_4)
5318                        + ((len - seed) * XXH_PRIME64_2);
5319            h128.low64  = XXH3_avalanche(h128.low64);
5320            h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
5321            return h128;
5322        }
5323    }
5324}
5325
5326XXH_FORCE_INLINE XXH128_hash_t
5327XXH3_hashLong_128b_internal(const void* XXH_RESTRICT input, size_t len,
5328                            const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
5329                            XXH3_f_accumulate_512 f_acc512,
5330                            XXH3_f_scrambleAcc f_scramble)
5331{
5332    XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;
5333
5334    XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, secret, secretSize, f_acc512, f_scramble);
5335
5336    /* converge into final hash */
5337    XXH_STATIC_ASSERT(sizeof(acc) == 64);
5338    XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
5339    {   XXH128_hash_t h128;
5340        h128.low64  = XXH3_mergeAccs(acc,
5341                                     secret + XXH_SECRET_MERGEACCS_START,
5342                                     (xxh_u64)len * XXH_PRIME64_1);
5343        h128.high64 = XXH3_mergeAccs(acc,
5344                                     secret + secretSize
5345                                            - sizeof(acc) - XXH_SECRET_MERGEACCS_START,
5346                                     ~((xxh_u64)len * XXH_PRIME64_2));
5347        return h128;
5348    }
5349}
5350
5351/*
5352 * It's important for performance that XXH3_hashLong is not inlined.
5353 */
5354XXH_NO_INLINE XXH128_hash_t
5355XXH3_hashLong_128b_default(const void* XXH_RESTRICT input, size_t len,
5356                           XXH64_hash_t seed64,
5357                           const void* XXH_RESTRICT secret, size_t secretLen)
5358{
5359    (void)seed64; (void)secret; (void)secretLen;
5360    return XXH3_hashLong_128b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret),
5361                                       XXH3_accumulate_512, XXH3_scrambleAcc);
5362}
5363
5364/*
5365 * It's important for performance to pass @secretLen (when it's static)
5366 * to the compiler, so that it can properly optimize the vectorized loop.
5367 */
5368XXH_FORCE_INLINE XXH128_hash_t
5369XXH3_hashLong_128b_withSecret(const void* XXH_RESTRICT input, size_t len,
5370                              XXH64_hash_t seed64,
5371                              const void* XXH_RESTRICT secret, size_t secretLen)
5372{
5373    (void)seed64;
5374    return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, secretLen,
5375                                       XXH3_accumulate_512, XXH3_scrambleAcc);
5376}
5377
5378XXH_FORCE_INLINE XXH128_hash_t
5379XXH3_hashLong_128b_withSeed_internal(const void* XXH_RESTRICT input, size_t len,
5380                                XXH64_hash_t seed64,
5381                                XXH3_f_accumulate_512 f_acc512,
5382                                XXH3_f_scrambleAcc f_scramble,
5383                                XXH3_f_initCustomSecret f_initSec)
5384{
5385    if (seed64 == 0)
5386        return XXH3_hashLong_128b_internal(input, len,
5387                                           XXH3_kSecret, sizeof(XXH3_kSecret),
5388                                           f_acc512, f_scramble);
5389    {   XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
5390        f_initSec(secret, seed64);
5391        return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, sizeof(secret),
5392                                           f_acc512, f_scramble);
5393    }
5394}
5395
5396/*
5397 * It's important for performance that XXH3_hashLong is not inlined.
5398 */
5399XXH_NO_INLINE XXH128_hash_t
5400XXH3_hashLong_128b_withSeed(const void* input, size_t len,
5401                            XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen)
5402{
5403    (void)secret; (void)secretLen;
5404    return XXH3_hashLong_128b_withSeed_internal(input, len, seed64,
5405                XXH3_accumulate_512, XXH3_scrambleAcc, XXH3_initCustomSecret);
5406}
5407
5408typedef XXH128_hash_t (*XXH3_hashLong128_f)(const void* XXH_RESTRICT, size_t,
5409                                            XXH64_hash_t, const void* XXH_RESTRICT, size_t);
5410
5411XXH_FORCE_INLINE XXH128_hash_t
5412XXH3_128bits_internal(const void* input, size_t len,
5413                      XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
5414                      XXH3_hashLong128_f f_hl128)
5415{
5416    XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
5417    /*
5418     * If an action is to be taken if `secret` conditions are not respected,
5419     * it should be done here.
5420     * For now, it's a contract pre-condition.
5421     * Adding a check and a branch here would cost performance at every hash.
5422     */
5423    if (len <= 16)
5424        return XXH3_len_0to16_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
5425    if (len <= 128)
5426        return XXH3_len_17to128_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
5427    if (len <= XXH3_MIDSIZE_MAX)
5428        return XXH3_len_129to240_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
5429    return f_hl128(input, len, seed64, secret, secretLen);
5430}
5431
5432
5433/* ===   Public XXH128 API   === */
5434
5435/*! @ingroup xxh3_family */
5436XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(const void* input, size_t len)
5437{
5438    return XXH3_128bits_internal(input, len, 0,
5439                                 XXH3_kSecret, sizeof(XXH3_kSecret),
5440                                 XXH3_hashLong_128b_default);
5441}
5442
5443/*! @ingroup xxh3_family */
5444XXH_PUBLIC_API XXH128_hash_t
5445XXH3_128bits_withSecret(const void* input, size_t len, const void* secret, size_t secretSize)
5446{
5447    return XXH3_128bits_internal(input, len, 0,
5448                                 (const xxh_u8*)secret, secretSize,
5449                                 XXH3_hashLong_128b_withSecret);
5450}
5451
5452/*! @ingroup xxh3_family */
5453XXH_PUBLIC_API XXH128_hash_t
5454XXH3_128bits_withSeed(const void* input, size_t len, XXH64_hash_t seed)
5455{
5456    return XXH3_128bits_internal(input, len, seed,
5457                                 XXH3_kSecret, sizeof(XXH3_kSecret),
5458                                 XXH3_hashLong_128b_withSeed);
5459}
5460
5461/*! @ingroup xxh3_family */
5462XXH_PUBLIC_API XXH128_hash_t
5463XXH3_128bits_withSecretandSeed(const void* input, size_t len, const void* secret, size_t secretSize, XXH64_hash_t seed)
5464{
5465    if (len <= XXH3_MIDSIZE_MAX)
5466        return XXH3_128bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), NULL);
5467    return XXH3_hashLong_128b_withSecret(input, len, seed, secret, secretSize);
5468}
5469
5470/*! @ingroup xxh3_family */
5471XXH_PUBLIC_API XXH128_hash_t
5472XXH128(const void* input, size_t len, XXH64_hash_t seed)
5473{
5474    return XXH3_128bits_withSeed(input, len, seed);
5475}
5476
5477
5478/* ===   XXH3 128-bit streaming   === */
5479
5480/*
5481 * All initialization and update functions are identical to 64-bit streaming variant.
5482 * The only difference is the finalization routine.
5483 */
5484
5485/*! @ingroup xxh3_family */
5486XXH_PUBLIC_API XXH_errorcode
5487XXH3_128bits_reset(XXH3_state_t* statePtr)
5488{
5489    return XXH3_64bits_reset(statePtr);
5490}
5491
5492/*! @ingroup xxh3_family */
5493XXH_PUBLIC_API XXH_errorcode
5494XXH3_128bits_reset_withSecret(XXH3_state_t* statePtr, const void* secret, size_t secretSize)
5495{
5496    return XXH3_64bits_reset_withSecret(statePtr, secret, secretSize);
5497}
5498
5499/*! @ingroup xxh3_family */
5500XXH_PUBLIC_API XXH_errorcode
5501XXH3_128bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
5502{
5503    return XXH3_64bits_reset_withSeed(statePtr, seed);
5504}
5505
5506/*! @ingroup xxh3_family */
5507XXH_PUBLIC_API XXH_errorcode
5508XXH3_128bits_reset_withSecretandSeed(XXH3_state_t* statePtr, const void* secret, size_t secretSize, XXH64_hash_t seed)
5509{
5510    return XXH3_64bits_reset_withSecretandSeed(statePtr, secret, secretSize, seed);
5511}
5512
5513/*! @ingroup xxh3_family */
5514XXH_PUBLIC_API XXH_errorcode
5515XXH3_128bits_update(XXH3_state_t* state, const void* input, size_t len)
5516{
5517    return XXH3_update(state, (const xxh_u8*)input, len,
5518                       XXH3_accumulate_512, XXH3_scrambleAcc);
5519}
5520
5521/*! @ingroup xxh3_family */
5522XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (const XXH3_state_t* state)
5523{
5524    const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
5525    if (state->totalLen > XXH3_MIDSIZE_MAX) {
5526        XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
5527        XXH3_digest_long(acc, state, secret);
5528        XXH_ASSERT(state->secretLimit + XXH_STRIPE_LEN >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
5529        {   XXH128_hash_t h128;
5530            h128.low64  = XXH3_mergeAccs(acc,
5531                                         secret + XXH_SECRET_MERGEACCS_START,
5532                                         (xxh_u64)state->totalLen * XXH_PRIME64_1);
5533            h128.high64 = XXH3_mergeAccs(acc,
5534                                         secret + state->secretLimit + XXH_STRIPE_LEN
5535                                                - sizeof(acc) - XXH_SECRET_MERGEACCS_START,
5536                                         ~((xxh_u64)state->totalLen * XXH_PRIME64_2));
5537            return h128;
5538        }
5539    }
5540    /* len <= XXH3_MIDSIZE_MAX : short code */
5541    if (state->seed)
5542        return XXH3_128bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
5543    return XXH3_128bits_withSecret(state->buffer, (size_t)(state->totalLen),
5544                                   secret, state->secretLimit + XXH_STRIPE_LEN);
5545}
5546
5547/* 128-bit utility functions */
5548
5549#include <string.h>   /* memcmp, memcpy */
5550
5551/* return : 1 is equal, 0 if different */
5552/*! @ingroup xxh3_family */
5553XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2)
5554{
5555    /* note : XXH128_hash_t is compact, it has no padding byte */
5556    return !(memcmp(&h1, &h2, sizeof(h1)));
5557}
5558
5559/* This prototype is compatible with stdlib's qsort().
5560 * return : >0 if *h128_1  > *h128_2
5561 *          <0 if *h128_1  < *h128_2
5562 *          =0 if *h128_1 == *h128_2  */
5563/*! @ingroup xxh3_family */
5564XXH_PUBLIC_API int XXH128_cmp(const void* h128_1, const void* h128_2)
5565{
5566    XXH128_hash_t const h1 = *(const XXH128_hash_t*)h128_1;
5567    XXH128_hash_t const h2 = *(const XXH128_hash_t*)h128_2;
5568    int const hcmp = (h1.high64 > h2.high64) - (h2.high64 > h1.high64);
5569    /* note : bets that, in most cases, hash values are different */
5570    if (hcmp) return hcmp;
5571    return (h1.low64 > h2.low64) - (h2.low64 > h1.low64);
5572}
5573
5574
5575/*======   Canonical representation   ======*/
5576/*! @ingroup xxh3_family */
5577XXH_PUBLIC_API void
5578XXH128_canonicalFromHash(XXH128_canonical_t* dst, XXH128_hash_t hash)
5579{
5580    XXH_STATIC_ASSERT(sizeof(XXH128_canonical_t) == sizeof(XXH128_hash_t));
5581    if (XXH_CPU_LITTLE_ENDIAN) {
5582        hash.high64 = XXH_swap64(hash.high64);
5583        hash.low64  = XXH_swap64(hash.low64);
5584    }
5585    XXH_memcpy(dst, &hash.high64, sizeof(hash.high64));
5586    XXH_memcpy((char*)dst + sizeof(hash.high64), &hash.low64, sizeof(hash.low64));
5587}
5588
5589/*! @ingroup xxh3_family */
5590XXH_PUBLIC_API XXH128_hash_t
5591XXH128_hashFromCanonical(const XXH128_canonical_t* src)
5592{
5593    XXH128_hash_t h;
5594    h.high64 = XXH_readBE64(src);
5595    h.low64  = XXH_readBE64(src->digest + 8);
5596    return h;
5597}
5598
5599
5600
5601/* ==========================================
5602 * Secret generators
5603 * ==========================================
5604 */
5605#define XXH_MIN(x, y) (((x) > (y)) ? (y) : (x))
5606
5607XXH_FORCE_INLINE void XXH3_combine16(void* dst, XXH128_hash_t h128)
5608{
5609    XXH_writeLE64( dst, XXH_readLE64(dst) ^ h128.low64 );
5610    XXH_writeLE64( (char*)dst+8, XXH_readLE64((char*)dst+8) ^ h128.high64 );
5611}
5612
5613/*! @ingroup xxh3_family */
5614XXH_PUBLIC_API XXH_errorcode
5615XXH3_generateSecret(void* secretBuffer, size_t secretSize, const void* customSeed, size_t customSeedSize)
5616{
5617#if (XXH_DEBUGLEVEL >= 1)
5618    XXH_ASSERT(secretBuffer != NULL);
5619    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
5620#else
5621    /* production mode, assert() are disabled */
5622    if (secretBuffer == NULL) return XXH_ERROR;
5623    if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
5624#endif
5625
5626    if (customSeedSize == 0) {
5627        customSeed = XXH3_kSecret;
5628        customSeedSize = XXH_SECRET_DEFAULT_SIZE;
5629    }
5630#if (XXH_DEBUGLEVEL >= 1)
5631    XXH_ASSERT(customSeed != NULL);
5632#else
5633    if (customSeed == NULL) return XXH_ERROR;
5634#endif
5635
5636    /* Fill secretBuffer with a copy of customSeed - repeat as needed */
5637    {   size_t pos = 0;
5638        while (pos < secretSize) {
5639            size_t const toCopy = XXH_MIN((secretSize - pos), customSeedSize);
5640            memcpy((char*)secretBuffer + pos, customSeed, toCopy);
5641            pos += toCopy;
5642    }   }
5643
5644    {   size_t const nbSeg16 = secretSize / 16;
5645        size_t n;
5646        XXH128_canonical_t scrambler;
5647        XXH128_canonicalFromHash(&scrambler, XXH128(customSeed, customSeedSize, 0));
5648        for (n=0; n<nbSeg16; n++) {
5649            XXH128_hash_t const h128 = XXH128(&scrambler, sizeof(scrambler), n);
5650            XXH3_combine16((char*)secretBuffer + n*16, h128);
5651        }
5652        /* last segment */
5653        XXH3_combine16((char*)secretBuffer + secretSize - 16, XXH128_hashFromCanonical(&scrambler));
5654    }
5655    return XXH_OK;
5656}
5657
5658/*! @ingroup xxh3_family */
5659XXH_PUBLIC_API void
5660XXH3_generateSecret_fromSeed(void* secretBuffer, XXH64_hash_t seed)
5661{
5662    XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
5663    XXH3_initCustomSecret(secret, seed);
5664    XXH_ASSERT(secretBuffer != NULL);
5665    memcpy(secretBuffer, secret, XXH_SECRET_DEFAULT_SIZE);
5666}
5667
5668
5669
5670/* Pop our optimization override from above */
5671#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
5672  && defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
5673  && defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) /* respect -O0 and -Os */
5674#  pragma GCC pop_options
5675#endif
5676
5677#endif  /* XXH_NO_LONG_LONG */
5678
5679#endif  /* XXH_NO_XXH3 */
5680
5681/*!
5682 * @}
5683 */
5684#endif  /* XXH_IMPLEMENTATION */
5685
5686
5687#if defined (__cplusplus)
5688}
5689#endif
5690