xref: /freebsd/sys/contrib/openzfs/module/zstd/lib/common/xxhash.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*
2  *  xxHash - Fast Hash algorithm
3  *  Copyright (c) 2012-2020, 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 /* *************************************
17 *  Tuning parameters
18 ***************************************/
19 /*!XXH_FORCE_MEMORY_ACCESS :
20  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
21  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
22  * The below switch allow to select different access method for improved performance.
23  * Method 0 (default) : use `memcpy()`. Safe and portable.
24  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
25  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
26  * Method 2 : direct access. This method doesn't depend on compiler but violate C standard.
27  *            It can generate buggy code on targets which do not support unaligned memory accesses.
28  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
29  * See http://stackoverflow.com/a/32095106/646947 for details.
30  * Prefer these methods in priority order (0 > 1 > 2)
31  */
32 #ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
33 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
34 #    define XXH_FORCE_MEMORY_ACCESS 2
35 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
36   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) )) || \
37   defined(__ICCARM__)
38 #    define XXH_FORCE_MEMORY_ACCESS 1
39 #  endif
40 #endif
41 
42 /*!XXH_ACCEPT_NULL_INPUT_POINTER :
43  * If the input pointer is a null pointer, xxHash default behavior is to trigger a memory access error, since it is a bad pointer.
44  * When this option is enabled, xxHash output for null input pointers will be the same as a null-length input.
45  * By default, this option is disabled. To enable it, uncomment below define :
46  */
47 /* #define XXH_ACCEPT_NULL_INPUT_POINTER 1 */
48 
49 /*!XXH_FORCE_NATIVE_FORMAT :
50  * By default, xxHash library provides endian-independent Hash values, based on little-endian convention.
51  * Results are therefore identical for little-endian and big-endian CPU.
52  * This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format.
53  * Should endian-independence be of no importance for your application, you may set the #define below to 1,
54  * to improve speed for Big-endian CPU.
55  * This option has no impact on Little_Endian CPU.
56  */
57 #ifndef XXH_FORCE_NATIVE_FORMAT   /* can be defined externally */
58 #  define XXH_FORCE_NATIVE_FORMAT 0
59 #endif
60 
61 /*!XXH_FORCE_ALIGN_CHECK :
62  * This is a minor performance trick, only useful with lots of very small keys.
63  * It means : check for aligned/unaligned input.
64  * The check costs one initial branch per hash; set to 0 when the input data
65  * is guaranteed to be aligned.
66  */
67 #ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
68 #  if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
69 #    define XXH_FORCE_ALIGN_CHECK 0
70 #  else
71 #    define XXH_FORCE_ALIGN_CHECK 1
72 #  endif
73 #endif
74 
75 
76 /* *************************************
77 *  Includes & Memory related functions
78 ***************************************/
79 /* Modify the local functions below should you wish to use some other memory routines */
80 /* for malloc(), free() */
81 #include <stdlib.h>
82 #include <stddef.h>     /* size_t */
83 static void* XXH_malloc(size_t s) { return malloc(s); }
84 static void  XXH_free  (void* p)  { free(p); }
85 /* for memcpy() */
86 #include <string.h>
87 static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }
88 
89 #ifndef XXH_STATIC_LINKING_ONLY
90 #  define XXH_STATIC_LINKING_ONLY
91 #endif
92 #include "xxhash.h"
93 
94 
95 /* *************************************
96 *  Compiler Specific Options
97 ***************************************/
98 #if (defined(__GNUC__) && !defined(__STRICT_ANSI__)) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
99 #  define INLINE_KEYWORD inline
100 #else
101 #  define INLINE_KEYWORD
102 #endif
103 
104 #if defined(__GNUC__) || defined(__ICCARM__)
105 #  define FORCE_INLINE_ATTR __attribute__((always_inline))
106 #elif defined(_MSC_VER)
107 #  define FORCE_INLINE_ATTR __forceinline
108 #else
109 #  define FORCE_INLINE_ATTR
110 #endif
111 
112 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
113 
114 
115 #ifdef _MSC_VER
116 #  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */
117 #endif
118 
119 
120 /* *************************************
121 *  Basic Types
122 ***************************************/
123 #ifndef MEM_MODULE
124 # define MEM_MODULE
125 # if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
126 #   include <stdint.h>
127     typedef uint8_t  BYTE;
128     typedef uint16_t U16;
129     typedef uint32_t U32;
130     typedef  int32_t S32;
131     typedef uint64_t U64;
132 #  else
133     typedef unsigned char      BYTE;
134     typedef unsigned short     U16;
135     typedef unsigned int       U32;
136     typedef   signed int       S32;
137     typedef unsigned long long U64;   /* if your compiler doesn't support unsigned long long, replace by another 64-bit type here. Note that xxhash.h will also need to be updated. */
138 #  endif
139 #endif
140 
141 
142 #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
143 
144 /* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
145 static U32 XXH_read32(const void* memPtr) { return *(const U32*) memPtr; }
146 static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
147 
148 #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
149 
150 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
151 /* currently only defined for gcc and icc */
152 typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign;
153 
154 static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
155 static U64 XXH_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
156 
157 #else
158 
159 /* portable and safe solution. Generally efficient.
160  * see : http://stackoverflow.com/a/32095106/646947
161  */
162 
163 static U32 XXH_read32(const void* memPtr)
164 {
165     U32 val;
166     memcpy(&val, memPtr, sizeof(val));
167     return val;
168 }
169 
170 static U64 XXH_read64(const void* memPtr)
171 {
172     U64 val;
173     memcpy(&val, memPtr, sizeof(val));
174     return val;
175 }
176 
177 #endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
178 
179 
180 /* ****************************************
181 *  Compiler-specific Functions and Macros
182 ******************************************/
183 #define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
184 
185 /* Note : although _rotl exists for minGW (GCC under windows), performance seems poor */
186 #if defined(_MSC_VER)
187 #  define XXH_rotl32(x,r) _rotl(x,r)
188 #  define XXH_rotl64(x,r) _rotl64(x,r)
189 #else
190 #if defined(__ICCARM__)
191 #  include <intrinsics.h>
192 #  define XXH_rotl32(x,r) __ROR(x,(32 - r))
193 #else
194 #  define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))
195 #endif
196 #  define XXH_rotl64(x,r) ((x << r) | (x >> (64 - r)))
197 #endif
198 
199 #if defined(_MSC_VER)     /* Visual Studio */
200 #  define XXH_swap32 _byteswap_ulong
201 #  define XXH_swap64 _byteswap_uint64
202 #elif GCC_VERSION >= 403
203 #  define XXH_swap32 __builtin_bswap32
204 #  define XXH_swap64 __builtin_bswap64
205 #else
206 static U32 XXH_swap32 (U32 x)
207 {
208     return  ((x << 24) & 0xff000000 ) |
209             ((x <<  8) & 0x00ff0000 ) |
210             ((x >>  8) & 0x0000ff00 ) |
211             ((x >> 24) & 0x000000ff );
212 }
213 static U64 XXH_swap64 (U64 x)
214 {
215     return  ((x << 56) & 0xff00000000000000ULL) |
216             ((x << 40) & 0x00ff000000000000ULL) |
217             ((x << 24) & 0x0000ff0000000000ULL) |
218             ((x << 8)  & 0x000000ff00000000ULL) |
219             ((x >> 8)  & 0x00000000ff000000ULL) |
220             ((x >> 24) & 0x0000000000ff0000ULL) |
221             ((x >> 40) & 0x000000000000ff00ULL) |
222             ((x >> 56) & 0x00000000000000ffULL);
223 }
224 #endif
225 
226 
227 /* *************************************
228 *  Architecture Macros
229 ***************************************/
230 typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;
231 
232 /* XXH_CPU_LITTLE_ENDIAN can be defined externally, for example on the compiler command line */
233 #ifndef XXH_CPU_LITTLE_ENDIAN
234     static const int g_one = 1;
235 #   define XXH_CPU_LITTLE_ENDIAN   (*(const char*)(&g_one))
236 #endif
237 
238 
239 /* ***************************
240 *  Memory reads
241 *****************************/
242 typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;
243 
244 FORCE_INLINE_TEMPLATE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
245 {
246     if (align==XXH_unaligned)
247         return endian==XXH_littleEndian ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
248     else
249         return endian==XXH_littleEndian ? *(const U32*)ptr : XXH_swap32(*(const U32*)ptr);
250 }
251 
252 FORCE_INLINE_TEMPLATE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)
253 {
254     return XXH_readLE32_align(ptr, endian, XXH_unaligned);
255 }
256 
257 static U32 XXH_readBE32(const void* ptr)
258 {
259     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
260 }
261 
262 FORCE_INLINE_TEMPLATE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
263 {
264     if (align==XXH_unaligned)
265         return endian==XXH_littleEndian ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
266     else
267         return endian==XXH_littleEndian ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);
268 }
269 
270 FORCE_INLINE_TEMPLATE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)
271 {
272     return XXH_readLE64_align(ptr, endian, XXH_unaligned);
273 }
274 
275 static U64 XXH_readBE64(const void* ptr)
276 {
277     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
278 }
279 
280 
281 /* *************************************
282 *  Macros
283 ***************************************/
284 #define XXH_STATIC_ASSERT(c)   { enum { XXH_static_assert = 1/(int)(!!(c)) }; }    /* use only *after* variable declarations */
285 
286 
287 /* *************************************
288 *  Constants
289 ***************************************/
290 static const U32 PRIME32_1 = 2654435761U;
291 static const U32 PRIME32_2 = 2246822519U;
292 static const U32 PRIME32_3 = 3266489917U;
293 static const U32 PRIME32_4 =  668265263U;
294 static const U32 PRIME32_5 =  374761393U;
295 
296 static const U64 PRIME64_1 = 11400714785074694791ULL;
297 static const U64 PRIME64_2 = 14029467366897019727ULL;
298 static const U64 PRIME64_3 =  1609587929392839161ULL;
299 static const U64 PRIME64_4 =  9650029242287828579ULL;
300 static const U64 PRIME64_5 =  2870177450012600261ULL;
301 
302 XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
303 
304 
305 /* **************************
306 *  Utils
307 ****************************/
308 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dstState, const XXH32_state_t* restrict srcState)
309 {
310     memcpy(dstState, srcState, sizeof(*dstState));
311 }
312 
313 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dstState, const XXH64_state_t* restrict srcState)
314 {
315     memcpy(dstState, srcState, sizeof(*dstState));
316 }
317 
318 
319 /* ***************************
320 *  Simple Hash Functions
321 *****************************/
322 
323 static U32 XXH32_round(U32 seed, U32 input)
324 {
325     seed += input * PRIME32_2;
326     seed  = XXH_rotl32(seed, 13);
327     seed *= PRIME32_1;
328     return seed;
329 }
330 
331 FORCE_INLINE_TEMPLATE U32 XXH32_endian_align(const void* input, size_t len, U32 seed, XXH_endianess endian, XXH_alignment align)
332 {
333     const BYTE* p = (const BYTE*)input;
334     const BYTE* bEnd = p + len;
335     U32 h32;
336 #define XXH_get32bits(p) XXH_readLE32_align(p, endian, align)
337 
338 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
339     if (p==NULL) {
340         len=0;
341         bEnd=p=(const BYTE*)(size_t)16;
342     }
343 #endif
344 
345     if (len>=16) {
346         const BYTE* const limit = bEnd - 16;
347         U32 v1 = seed + PRIME32_1 + PRIME32_2;
348         U32 v2 = seed + PRIME32_2;
349         U32 v3 = seed + 0;
350         U32 v4 = seed - PRIME32_1;
351 
352         do {
353             v1 = XXH32_round(v1, XXH_get32bits(p)); p+=4;
354             v2 = XXH32_round(v2, XXH_get32bits(p)); p+=4;
355             v3 = XXH32_round(v3, XXH_get32bits(p)); p+=4;
356             v4 = XXH32_round(v4, XXH_get32bits(p)); p+=4;
357         } while (p<=limit);
358 
359         h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
360     } else {
361         h32  = seed + PRIME32_5;
362     }
363 
364     h32 += (U32) len;
365 
366     while (p+4<=bEnd) {
367         h32 += XXH_get32bits(p) * PRIME32_3;
368         h32  = XXH_rotl32(h32, 17) * PRIME32_4 ;
369         p+=4;
370     }
371 
372     while (p<bEnd) {
373         h32 += (*p) * PRIME32_5;
374         h32 = XXH_rotl32(h32, 11) * PRIME32_1 ;
375         p++;
376     }
377 
378     h32 ^= h32 >> 15;
379     h32 *= PRIME32_2;
380     h32 ^= h32 >> 13;
381     h32 *= PRIME32_3;
382     h32 ^= h32 >> 16;
383 
384     return h32;
385 }
386 
387 
388 XXH_PUBLIC_API unsigned int XXH32 (const void* input, size_t len, unsigned int seed)
389 {
390 #if 0
391     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
392     XXH32_CREATESTATE_STATIC(state);
393     XXH32_reset(state, seed);
394     XXH32_update(state, input, len);
395     return XXH32_digest(state);
396 #else
397     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
398 
399     if (XXH_FORCE_ALIGN_CHECK) {
400         if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */
401             if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
402                 return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
403             else
404                 return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
405     }   }
406 
407     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
408         return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
409     else
410         return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
411 #endif
412 }
413 
414 
415 static U64 XXH64_round(U64 acc, U64 input)
416 {
417     acc += input * PRIME64_2;
418     acc  = XXH_rotl64(acc, 31);
419     acc *= PRIME64_1;
420     return acc;
421 }
422 
423 static U64 XXH64_mergeRound(U64 acc, U64 val)
424 {
425     val  = XXH64_round(0, val);
426     acc ^= val;
427     acc  = acc * PRIME64_1 + PRIME64_4;
428     return acc;
429 }
430 
431 FORCE_INLINE_TEMPLATE U64 XXH64_endian_align(const void* input, size_t len, U64 seed, XXH_endianess endian, XXH_alignment align)
432 {
433     const BYTE* p = (const BYTE*)input;
434     const BYTE* const bEnd = p + len;
435     U64 h64;
436 #define XXH_get64bits(p) XXH_readLE64_align(p, endian, align)
437 
438 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
439     if (p==NULL) {
440         len=0;
441         bEnd=p=(const BYTE*)(size_t)32;
442     }
443 #endif
444 
445     if (len>=32) {
446         const BYTE* const limit = bEnd - 32;
447         U64 v1 = seed + PRIME64_1 + PRIME64_2;
448         U64 v2 = seed + PRIME64_2;
449         U64 v3 = seed + 0;
450         U64 v4 = seed - PRIME64_1;
451 
452         do {
453             v1 = XXH64_round(v1, XXH_get64bits(p)); p+=8;
454             v2 = XXH64_round(v2, XXH_get64bits(p)); p+=8;
455             v3 = XXH64_round(v3, XXH_get64bits(p)); p+=8;
456             v4 = XXH64_round(v4, XXH_get64bits(p)); p+=8;
457         } while (p<=limit);
458 
459         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
460         h64 = XXH64_mergeRound(h64, v1);
461         h64 = XXH64_mergeRound(h64, v2);
462         h64 = XXH64_mergeRound(h64, v3);
463         h64 = XXH64_mergeRound(h64, v4);
464 
465     } else {
466         h64  = seed + PRIME64_5;
467     }
468 
469     h64 += (U64) len;
470 
471     while (p+8<=bEnd) {
472         U64 const k1 = XXH64_round(0, XXH_get64bits(p));
473         h64 ^= k1;
474         h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4;
475         p+=8;
476     }
477 
478     if (p+4<=bEnd) {
479         h64 ^= (U64)(XXH_get32bits(p)) * PRIME64_1;
480         h64 = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
481         p+=4;
482     }
483 
484     while (p<bEnd) {
485         h64 ^= (*p) * PRIME64_5;
486         h64 = XXH_rotl64(h64, 11) * PRIME64_1;
487         p++;
488     }
489 
490     h64 ^= h64 >> 33;
491     h64 *= PRIME64_2;
492     h64 ^= h64 >> 29;
493     h64 *= PRIME64_3;
494     h64 ^= h64 >> 32;
495 
496     return h64;
497 }
498 
499 
500 XXH_PUBLIC_API unsigned long long XXH64 (const void* input, size_t len, unsigned long long seed)
501 {
502 #if 0
503     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
504     XXH64_CREATESTATE_STATIC(state);
505     XXH64_reset(state, seed);
506     XXH64_update(state, input, len);
507     return XXH64_digest(state);
508 #else
509     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
510 
511     if (XXH_FORCE_ALIGN_CHECK) {
512         if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */
513             if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
514                 return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
515             else
516                 return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
517     }   }
518 
519     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
520         return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
521     else
522         return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
523 #endif
524 }
525 
526 
527 /* **************************************************
528 *  Advanced Hash Functions
529 ****************************************************/
530 
531 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
532 {
533     return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
534 }
535 XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
536 {
537     XXH_free(statePtr);
538     return XXH_OK;
539 }
540 
541 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
542 {
543     return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
544 }
545 XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
546 {
547     XXH_free(statePtr);
548     return XXH_OK;
549 }
550 
551 
552 /*** Hash feed ***/
553 
554 XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, unsigned int seed)
555 {
556     XXH32_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
557     memset(&state, 0, sizeof(state)-4);   /* do not write into reserved, for future removal */
558     state.v1 = seed + PRIME32_1 + PRIME32_2;
559     state.v2 = seed + PRIME32_2;
560     state.v3 = seed + 0;
561     state.v4 = seed - PRIME32_1;
562     memcpy(statePtr, &state, sizeof(state));
563     return XXH_OK;
564 }
565 
566 
567 XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long long seed)
568 {
569     XXH64_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
570     memset(&state, 0, sizeof(state)-8);   /* do not write into reserved, for future removal */
571     state.v1 = seed + PRIME64_1 + PRIME64_2;
572     state.v2 = seed + PRIME64_2;
573     state.v3 = seed + 0;
574     state.v4 = seed - PRIME64_1;
575     memcpy(statePtr, &state, sizeof(state));
576     return XXH_OK;
577 }
578 
579 
580 FORCE_INLINE_TEMPLATE XXH_errorcode XXH32_update_endian (XXH32_state_t* state, const void* input, size_t len, XXH_endianess endian)
581 {
582     const BYTE* p = (const BYTE*)input;
583     const BYTE* const bEnd = p + len;
584 
585 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
586     if (input==NULL) return XXH_ERROR;
587 #endif
588 
589     state->total_len_32 += (unsigned)len;
590     state->large_len |= (len>=16) | (state->total_len_32>=16);
591 
592     if (state->memsize + len < 16)  {   /* fill in tmp buffer */
593         XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, len);
594         state->memsize += (unsigned)len;
595         return XXH_OK;
596     }
597 
598     if (state->memsize) {   /* some data left from previous update */
599         XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, 16-state->memsize);
600         {   const U32* p32 = state->mem32;
601             state->v1 = XXH32_round(state->v1, XXH_readLE32(p32, endian)); p32++;
602             state->v2 = XXH32_round(state->v2, XXH_readLE32(p32, endian)); p32++;
603             state->v3 = XXH32_round(state->v3, XXH_readLE32(p32, endian)); p32++;
604             state->v4 = XXH32_round(state->v4, XXH_readLE32(p32, endian)); p32++;
605         }
606         p += 16-state->memsize;
607         state->memsize = 0;
608     }
609 
610     if (p <= bEnd-16) {
611         const BYTE* const limit = bEnd - 16;
612         U32 v1 = state->v1;
613         U32 v2 = state->v2;
614         U32 v3 = state->v3;
615         U32 v4 = state->v4;
616 
617         do {
618             v1 = XXH32_round(v1, XXH_readLE32(p, endian)); p+=4;
619             v2 = XXH32_round(v2, XXH_readLE32(p, endian)); p+=4;
620             v3 = XXH32_round(v3, XXH_readLE32(p, endian)); p+=4;
621             v4 = XXH32_round(v4, XXH_readLE32(p, endian)); p+=4;
622         } while (p<=limit);
623 
624         state->v1 = v1;
625         state->v2 = v2;
626         state->v3 = v3;
627         state->v4 = v4;
628     }
629 
630     if (p < bEnd) {
631         XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
632         state->memsize = (unsigned)(bEnd-p);
633     }
634 
635     return XXH_OK;
636 }
637 
638 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* state_in, const void* input, size_t len)
639 {
640     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
641 
642     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
643         return XXH32_update_endian(state_in, input, len, XXH_littleEndian);
644     else
645         return XXH32_update_endian(state_in, input, len, XXH_bigEndian);
646 }
647 
648 
649 
650 FORCE_INLINE_TEMPLATE U32 XXH32_digest_endian (const XXH32_state_t* state, XXH_endianess endian)
651 {
652     const BYTE * p = (const BYTE*)state->mem32;
653     const BYTE* const bEnd = (const BYTE*)(state->mem32) + state->memsize;
654     U32 h32;
655 
656     if (state->large_len) {
657         h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) + XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18);
658     } else {
659         h32 = state->v3 /* == seed */ + PRIME32_5;
660     }
661 
662     h32 += state->total_len_32;
663 
664     while (p+4<=bEnd) {
665         h32 += XXH_readLE32(p, endian) * PRIME32_3;
666         h32  = XXH_rotl32(h32, 17) * PRIME32_4;
667         p+=4;
668     }
669 
670     while (p<bEnd) {
671         h32 += (*p) * PRIME32_5;
672         h32  = XXH_rotl32(h32, 11) * PRIME32_1;
673         p++;
674     }
675 
676     h32 ^= h32 >> 15;
677     h32 *= PRIME32_2;
678     h32 ^= h32 >> 13;
679     h32 *= PRIME32_3;
680     h32 ^= h32 >> 16;
681 
682     return h32;
683 }
684 
685 
686 XXH_PUBLIC_API unsigned int XXH32_digest (const XXH32_state_t* state_in)
687 {
688     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
689 
690     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
691         return XXH32_digest_endian(state_in, XXH_littleEndian);
692     else
693         return XXH32_digest_endian(state_in, XXH_bigEndian);
694 }
695 
696 
697 
698 /* **** XXH64 **** */
699 
700 FORCE_INLINE_TEMPLATE XXH_errorcode XXH64_update_endian (XXH64_state_t* state, const void* input, size_t len, XXH_endianess endian)
701 {
702     const BYTE* p = (const BYTE*)input;
703     const BYTE* const bEnd = p + len;
704 
705 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
706     if (input==NULL) return XXH_ERROR;
707 #endif
708 
709     state->total_len += len;
710 
711     if (state->memsize + len < 32) {  /* fill in tmp buffer */
712         if (input != NULL) {
713             XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, len);
714         }
715         state->memsize += (U32)len;
716         return XXH_OK;
717     }
718 
719     if (state->memsize) {   /* tmp buffer is full */
720         XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, 32-state->memsize);
721         state->v1 = XXH64_round(state->v1, XXH_readLE64(state->mem64+0, endian));
722         state->v2 = XXH64_round(state->v2, XXH_readLE64(state->mem64+1, endian));
723         state->v3 = XXH64_round(state->v3, XXH_readLE64(state->mem64+2, endian));
724         state->v4 = XXH64_round(state->v4, XXH_readLE64(state->mem64+3, endian));
725         p += 32-state->memsize;
726         state->memsize = 0;
727     }
728 
729     if (p+32 <= bEnd) {
730         const BYTE* const limit = bEnd - 32;
731         U64 v1 = state->v1;
732         U64 v2 = state->v2;
733         U64 v3 = state->v3;
734         U64 v4 = state->v4;
735 
736         do {
737             v1 = XXH64_round(v1, XXH_readLE64(p, endian)); p+=8;
738             v2 = XXH64_round(v2, XXH_readLE64(p, endian)); p+=8;
739             v3 = XXH64_round(v3, XXH_readLE64(p, endian)); p+=8;
740             v4 = XXH64_round(v4, XXH_readLE64(p, endian)); p+=8;
741         } while (p<=limit);
742 
743         state->v1 = v1;
744         state->v2 = v2;
745         state->v3 = v3;
746         state->v4 = v4;
747     }
748 
749     if (p < bEnd) {
750         XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
751         state->memsize = (unsigned)(bEnd-p);
752     }
753 
754     return XXH_OK;
755 }
756 
757 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* state_in, const void* input, size_t len)
758 {
759     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
760 
761     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
762         return XXH64_update_endian(state_in, input, len, XXH_littleEndian);
763     else
764         return XXH64_update_endian(state_in, input, len, XXH_bigEndian);
765 }
766 
767 
768 
769 FORCE_INLINE_TEMPLATE U64 XXH64_digest_endian (const XXH64_state_t* state, XXH_endianess endian)
770 {
771     const BYTE * p = (const BYTE*)state->mem64;
772     const BYTE* const bEnd = (const BYTE*)state->mem64 + state->memsize;
773     U64 h64;
774 
775     if (state->total_len >= 32) {
776         U64 const v1 = state->v1;
777         U64 const v2 = state->v2;
778         U64 const v3 = state->v3;
779         U64 const v4 = state->v4;
780 
781         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
782         h64 = XXH64_mergeRound(h64, v1);
783         h64 = XXH64_mergeRound(h64, v2);
784         h64 = XXH64_mergeRound(h64, v3);
785         h64 = XXH64_mergeRound(h64, v4);
786     } else {
787         h64  = state->v3 + PRIME64_5;
788     }
789 
790     h64 += (U64) state->total_len;
791 
792     while (p+8<=bEnd) {
793         U64 const k1 = XXH64_round(0, XXH_readLE64(p, endian));
794         h64 ^= k1;
795         h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4;
796         p+=8;
797     }
798 
799     if (p+4<=bEnd) {
800         h64 ^= (U64)(XXH_readLE32(p, endian)) * PRIME64_1;
801         h64  = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
802         p+=4;
803     }
804 
805     while (p<bEnd) {
806         h64 ^= (*p) * PRIME64_5;
807         h64  = XXH_rotl64(h64, 11) * PRIME64_1;
808         p++;
809     }
810 
811     h64 ^= h64 >> 33;
812     h64 *= PRIME64_2;
813     h64 ^= h64 >> 29;
814     h64 *= PRIME64_3;
815     h64 ^= h64 >> 32;
816 
817     return h64;
818 }
819 
820 
821 XXH_PUBLIC_API unsigned long long XXH64_digest (const XXH64_state_t* state_in)
822 {
823     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
824 
825     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
826         return XXH64_digest_endian(state_in, XXH_littleEndian);
827     else
828         return XXH64_digest_endian(state_in, XXH_bigEndian);
829 }
830 
831 
832 /* **************************
833 *  Canonical representation
834 ****************************/
835 
836 /*! Default XXH result types are basic unsigned 32 and 64 bits.
837 *   The canonical representation follows human-readable write convention, aka big-endian (large digits first).
838 *   These functions allow transformation of hash result into and from its canonical format.
839 *   This way, hash values can be written into a file or buffer, and remain comparable across different systems and programs.
840 */
841 
842 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
843 {
844     XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
845     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
846     memcpy(dst, &hash, sizeof(*dst));
847 }
848 
849 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
850 {
851     XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
852     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
853     memcpy(dst, &hash, sizeof(*dst));
854 }
855 
856 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
857 {
858     return XXH_readBE32(src);
859 }
860 
861 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
862 {
863     return XXH_readBE64(src);
864 }
865