lib/xxhash.c - linux - Git at Google

 /*
  * xxHash - Extremely Fast Hash algorithm
  * Copyright (C) 2012-2016, Yann Collet.
  *
  * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *   * Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *   * Redistributions in binary form must reproduce the above
  *     copyright notice, this list of conditions and the following disclaimer
  *     in the documentation and/or other materials provided with the
  *     distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * This program is free software; you can redistribute it and/or modify it under
  * the terms of the GNU General Public License version 2 as published by the
  * Free Software Foundation. This program is dual-licensed; you may select
  * either version 2 of the GNU General Public License ("GPL") or BSD license
  * ("BSD").
  *
  * You can contact the author at:
  * - xxHash homepage: https://cyan4973.github.io/xxHash/
  * - xxHash source repository: https://github.com/Cyan4973/xxHash
  */

 #include <linux/unaligned.h>
 #include <linux/errno.h>
 #include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/xxhash.h>

 /*-*************************************
  * Macros
  **************************************/
 #define xxh_rotl32(x, r) ((x << r) | (x >> (32 - r)))
 #define xxh_rotl64(x, r) ((x << r) | (x >> (64 - r)))

 #ifdef __LITTLE_ENDIAN
 # define XXH_CPU_LITTLE_ENDIAN 1
 #else
 # define XXH_CPU_LITTLE_ENDIAN 0
 #endif

 /*-*************************************
  * Constants
  **************************************/
 static const uint32_t PRIME32_1 = 2654435761U;
 static const uint32_t PRIME32_2 = 2246822519U;
 static const uint32_t PRIME32_3 = 3266489917U;
 static const uint32_t PRIME32_4 =  668265263U;
 static const uint32_t PRIME32_5 =  374761393U;

 static const uint64_t PRIME64_1 = 11400714785074694791ULL;
 static const uint64_t PRIME64_2 = 14029467366897019727ULL;
 static const uint64_t PRIME64_3 =  1609587929392839161ULL;
 static const uint64_t PRIME64_4 =  9650029242287828579ULL;
 static const uint64_t PRIME64_5 =  2870177450012600261ULL;

 /*-**************************
  *  Utils
  ***************************/
 void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src)
 {
 	memcpy(dst, src, sizeof(*dst));
 }
 EXPORT_SYMBOL(xxh32_copy_state);

 void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src)
 {
 	memcpy(dst, src, sizeof(*dst));
 }
 EXPORT_SYMBOL(xxh64_copy_state);

 /*-***************************
  * Simple Hash Functions
  ****************************/
 static uint32_t xxh32_round(uint32_t seed, const uint32_t input)
 {
 	seed += input * PRIME32_2;
 	seed = xxh_rotl32(seed, 13);
 	seed *= PRIME32_1;
 	return seed;
 }

 uint32_t xxh32(const void *input, const size_t len, const uint32_t seed)
 {
 	const uint8_t *p = (const uint8_t *)input;
 	const uint8_t *b_end = p + len;
 	uint32_t h32;

 	if (len >= 16) {
 		const uint8_t *const limit = b_end - 16;
 		uint32_t v1 = seed + PRIME32_1 + PRIME32_2;
 		uint32_t v2 = seed + PRIME32_2;
 		uint32_t v3 = seed + 0;
 		uint32_t v4 = seed - PRIME32_1;

 		do {
 			v1 = xxh32_round(v1, get_unaligned_le32(p));
 			p += 4;
 			v2 = xxh32_round(v2, get_unaligned_le32(p));
 			p += 4;
 			v3 = xxh32_round(v3, get_unaligned_le32(p));
 			p += 4;
 			v4 = xxh32_round(v4, get_unaligned_le32(p));
 			p += 4;
 		} while (p <= limit);

 		h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) +
 			xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18);
 	} else {
 		h32 = seed + PRIME32_5;
 	}

 	h32 += (uint32_t)len;

 	while (p + 4 <= b_end) {
 		h32 += get_unaligned_le32(p) * PRIME32_3;
 		h32 = xxh_rotl32(h32, 17) * PRIME32_4;
 		p += 4;
 	}

 	while (p < b_end) {
 		h32 += (*p) * PRIME32_5;
 		h32 = xxh_rotl32(h32, 11) * PRIME32_1;
 		p++;
 	}

 	h32 ^= h32 >> 15;
 	h32 *= PRIME32_2;
 	h32 ^= h32 >> 13;
 	h32 *= PRIME32_3;
 	h32 ^= h32 >> 16;

 	return h32;
 }
 EXPORT_SYMBOL(xxh32);

 static uint64_t xxh64_round(uint64_t acc, const uint64_t input)
 {
 	acc += input * PRIME64_2;
 	acc = xxh_rotl64(acc, 31);
 	acc *= PRIME64_1;
 	return acc;
 }

 static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val)
 {
 	val = xxh64_round(0, val);
 	acc ^= val;
 	acc = acc * PRIME64_1 + PRIME64_4;
 	return acc;
 }

 uint64_t xxh64(const void *input, const size_t len, const uint64_t seed)
 {
 	const uint8_t *p = (const uint8_t *)input;
 	const uint8_t *const b_end = p + len;
 	uint64_t h64;

 	if (len >= 32) {
 		const uint8_t *const limit = b_end - 32;
 		uint64_t v1 = seed + PRIME64_1 + PRIME64_2;
 		uint64_t v2 = seed + PRIME64_2;
 		uint64_t v3 = seed + 0;
 		uint64_t v4 = seed - PRIME64_1;

 		do {
 			v1 = xxh64_round(v1, get_unaligned_le64(p));
 			p += 8;
 			v2 = xxh64_round(v2, get_unaligned_le64(p));
 			p += 8;
 			v3 = xxh64_round(v3, get_unaligned_le64(p));
 			p += 8;
 			v4 = xxh64_round(v4, get_unaligned_le64(p));
 			p += 8;
 		} while (p <= limit);

 		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
 			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
 		h64 = xxh64_merge_round(h64, v1);
 		h64 = xxh64_merge_round(h64, v2);
 		h64 = xxh64_merge_round(h64, v3);
 		h64 = xxh64_merge_round(h64, v4);

 	} else {
 		h64  = seed + PRIME64_5;
 	}

 	h64 += (uint64_t)len;

 	while (p + 8 <= b_end) {
 		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));

 		h64 ^= k1;
 		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
 		p += 8;
 	}

 	if (p + 4 <= b_end) {
 		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
 		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
 		p += 4;
 	}

 	while (p < b_end) {
 		h64 ^= (*p) * PRIME64_5;
 		h64 = xxh_rotl64(h64, 11) * PRIME64_1;
 		p++;
 	}

 	h64 ^= h64 >> 33;
 	h64 *= PRIME64_2;
 	h64 ^= h64 >> 29;
 	h64 *= PRIME64_3;
 	h64 ^= h64 >> 32;

 	return h64;
 }
 EXPORT_SYMBOL(xxh64);

 /*-**************************************************
  * Advanced Hash Functions
  ***************************************************/
 void xxh32_reset(struct xxh32_state *statePtr, const uint32_t seed)
 {
 	/* use a local state for memcpy() to avoid strict-aliasing warnings */
 	struct xxh32_state state;

 	memset(&state, 0, sizeof(state));
 	state.v1 = seed + PRIME32_1 + PRIME32_2;
 	state.v2 = seed + PRIME32_2;
 	state.v3 = seed + 0;
 	state.v4 = seed - PRIME32_1;
 	memcpy(statePtr, &state, sizeof(state));
 }
 EXPORT_SYMBOL(xxh32_reset);

 void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed)
 {
 	/* use a local state for memcpy() to avoid strict-aliasing warnings */
 	struct xxh64_state state;

 	memset(&state, 0, sizeof(state));
 	state.v1 = seed + PRIME64_1 + PRIME64_2;
 	state.v2 = seed + PRIME64_2;
 	state.v3 = seed + 0;
 	state.v4 = seed - PRIME64_1;
 	memcpy(statePtr, &state, sizeof(state));
 }
 EXPORT_SYMBOL(xxh64_reset);

 int xxh32_update(struct xxh32_state *state, const void *input, const size_t len)
 {
 	const uint8_t *p = (const uint8_t *)input;
 	const uint8_t *const b_end = p + len;

 	if (input == NULL)
 		return -EINVAL;

 	state->total_len_32 += (uint32_t)len;
 	state->large_len |= (len >= 16) | (state->total_len_32 >= 16);

 	if (state->memsize + len < 16) { /* fill in tmp buffer */
 		memcpy((uint8_t *)(state->mem32) + state->memsize, input, len);
 		state->memsize += (uint32_t)len;
 		return 0;
 	}

 	if (state->memsize) { /* some data left from previous update */
 		const uint32_t *p32 = state->mem32;

 		memcpy((uint8_t *)(state->mem32) + state->memsize, input,
 			16 - state->memsize);

 		state->v1 = xxh32_round(state->v1, get_unaligned_le32(p32));
 		p32++;
 		state->v2 = xxh32_round(state->v2, get_unaligned_le32(p32));
 		p32++;
 		state->v3 = xxh32_round(state->v3, get_unaligned_le32(p32));
 		p32++;
 		state->v4 = xxh32_round(state->v4, get_unaligned_le32(p32));
 		p32++;

 		p += 16-state->memsize;
 		state->memsize = 0;
 	}

 	if (p <= b_end - 16) {
 		const uint8_t *const limit = b_end - 16;
 		uint32_t v1 = state->v1;
 		uint32_t v2 = state->v2;
 		uint32_t v3 = state->v3;
 		uint32_t v4 = state->v4;

 		do {
 			v1 = xxh32_round(v1, get_unaligned_le32(p));
 			p += 4;
 			v2 = xxh32_round(v2, get_unaligned_le32(p));
 			p += 4;
 			v3 = xxh32_round(v3, get_unaligned_le32(p));
 			p += 4;
 			v4 = xxh32_round(v4, get_unaligned_le32(p));
 			p += 4;
 		} while (p <= limit);

 		state->v1 = v1;
 		state->v2 = v2;
 		state->v3 = v3;
 		state->v4 = v4;
 	}

 	if (p < b_end) {
 		memcpy(state->mem32, p, (size_t)(b_end-p));
 		state->memsize = (uint32_t)(b_end-p);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(xxh32_update);

 uint32_t xxh32_digest(const struct xxh32_state *state)
 {
 	const uint8_t *p = (const uint8_t *)state->mem32;
 	const uint8_t *const b_end = (const uint8_t *)(state->mem32) +
 		state->memsize;
 	uint32_t h32;

 	if (state->large_len) {
 		h32 = xxh_rotl32(state->v1, 1) + xxh_rotl32(state->v2, 7) +
 			xxh_rotl32(state->v3, 12) + xxh_rotl32(state->v4, 18);
 	} else {
 		h32 = state->v3 /* == seed */ + PRIME32_5;
 	}

 	h32 += state->total_len_32;

 	while (p + 4 <= b_end) {
 		h32 += get_unaligned_le32(p) * PRIME32_3;
 		h32 = xxh_rotl32(h32, 17) * PRIME32_4;
 		p += 4;
 	}

 	while (p < b_end) {
 		h32 += (*p) * PRIME32_5;
 		h32 = xxh_rotl32(h32, 11) * PRIME32_1;
 		p++;
 	}

 	h32 ^= h32 >> 15;
 	h32 *= PRIME32_2;
 	h32 ^= h32 >> 13;
 	h32 *= PRIME32_3;
 	h32 ^= h32 >> 16;

 	return h32;
 }
 EXPORT_SYMBOL(xxh32_digest);

 int xxh64_update(struct xxh64_state *state, const void *input, const size_t len)
 {
 	const uint8_t *p = (const uint8_t *)input;
 	const uint8_t *const b_end = p + len;

 	if (input == NULL)
 		return -EINVAL;

 	state->total_len += len;

 	if (state->memsize + len < 32) { /* fill in tmp buffer */
 		memcpy(((uint8_t *)state->mem64) + state->memsize, input, len);
 		state->memsize += (uint32_t)len;
 		return 0;
 	}

 	if (state->memsize) { /* tmp buffer is full */
 		uint64_t *p64 = state->mem64;

 		memcpy(((uint8_t *)p64) + state->memsize, input,
 			32 - state->memsize);

 		state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64));
 		p64++;
 		state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64));
 		p64++;
 		state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64));
 		p64++;
 		state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64));

 		p += 32 - state->memsize;
 		state->memsize = 0;
 	}

 	if (p + 32 <= b_end) {
 		const uint8_t *const limit = b_end - 32;
 		uint64_t v1 = state->v1;
 		uint64_t v2 = state->v2;
 		uint64_t v3 = state->v3;
 		uint64_t v4 = state->v4;

 		do {
 			v1 = xxh64_round(v1, get_unaligned_le64(p));
 			p += 8;
 			v2 = xxh64_round(v2, get_unaligned_le64(p));
 			p += 8;
 			v3 = xxh64_round(v3, get_unaligned_le64(p));
 			p += 8;
 			v4 = xxh64_round(v4, get_unaligned_le64(p));
 			p += 8;
 		} while (p <= limit);

 		state->v1 = v1;
 		state->v2 = v2;
 		state->v3 = v3;
 		state->v4 = v4;
 	}

 	if (p < b_end) {
 		memcpy(state->mem64, p, (size_t)(b_end-p));
 		state->memsize = (uint32_t)(b_end - p);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(xxh64_update);

 uint64_t xxh64_digest(const struct xxh64_state *state)
 {
 	const uint8_t *p = (const uint8_t *)state->mem64;
 	const uint8_t *const b_end = (const uint8_t *)state->mem64 +
 		state->memsize;
 	uint64_t h64;

 	if (state->total_len >= 32) {
 		const uint64_t v1 = state->v1;
 		const uint64_t v2 = state->v2;
 		const uint64_t v3 = state->v3;
 		const uint64_t v4 = state->v4;

 		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
 			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
 		h64 = xxh64_merge_round(h64, v1);
 		h64 = xxh64_merge_round(h64, v2);
 		h64 = xxh64_merge_round(h64, v3);
 		h64 = xxh64_merge_round(h64, v4);
 	} else {
 		h64  = state->v3 + PRIME64_5;
 	}

 	h64 += (uint64_t)state->total_len;

 	while (p + 8 <= b_end) {
 		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));

 		h64 ^= k1;
 		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
 		p += 8;
 	}

 	if (p + 4 <= b_end) {
 		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
 		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
 		p += 4;
 	}

 	while (p < b_end) {
 		h64 ^= (*p) * PRIME64_5;
 		h64 = xxh_rotl64(h64, 11) * PRIME64_1;
 		p++;
 	}

 	h64 ^= h64 >> 33;
 	h64 *= PRIME64_2;
 	h64 ^= h64 >> 29;
 	h64 *= PRIME64_3;
 	h64 ^= h64 >> 32;

 	return h64;
 }
 EXPORT_SYMBOL(xxh64_digest);

 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_DESCRIPTION("xxHash");
	/*
	* xxHash - Extremely Fast Hash algorithm
	* Copyright (C) 2012-2016, Yann Collet.
	*
	* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following disclaimer
	* in the documentation and/or other materials provided with the
	* distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	* This program is free software; you can redistribute it and/or modify it under
	* the terms of the GNU General Public License version 2 as published by the
	* Free Software Foundation. This program is dual-licensed; you may select
	* either version 2 of the GNU General Public License ("GPL") or BSD license
	* ("BSD").
	*
	* You can contact the author at:
	* - xxHash homepage: https://cyan4973.github.io/xxHash/
	* - xxHash source repository: https://github.com/Cyan4973/xxHash
	*/

	#include <linux/unaligned.h>
	#include <linux/errno.h>
	#include <linux/compiler.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/string.h>
	#include <linux/xxhash.h>

	/-************************************
	* Macros
	**************************************/
	#define xxh_rotl32(x, r) ((x << r) \| (x >> (32 - r)))
	#define xxh_rotl64(x, r) ((x << r) \| (x >> (64 - r)))

	#ifdef __LITTLE_ENDIAN
	# define XXH_CPU_LITTLE_ENDIAN 1
	#else
	# define XXH_CPU_LITTLE_ENDIAN 0
	#endif

	/-************************************
	* Constants
	**************************************/
	static const uint32_t PRIME32_1 = 2654435761U;
	static const uint32_t PRIME32_2 = 2246822519U;
	static const uint32_t PRIME32_3 = 3266489917U;
	static const uint32_t PRIME32_4 = 668265263U;
	static const uint32_t PRIME32_5 = 374761393U;

	static const uint64_t PRIME64_1 = 11400714785074694791ULL;
	static const uint64_t PRIME64_2 = 14029467366897019727ULL;
	static const uint64_t PRIME64_3 = 1609587929392839161ULL;
	static const uint64_t PRIME64_4 = 9650029242287828579ULL;
	static const uint64_t PRIME64_5 = 2870177450012600261ULL;

	/-*************************
	* Utils
	***************************/
	void xxh32_copy_state(struct xxh32_state dst, const struct xxh32_state src)
	{
	memcpy(dst, src, sizeof(*dst));
	}
	EXPORT_SYMBOL(xxh32_copy_state);

	void xxh64_copy_state(struct xxh64_state dst, const struct xxh64_state src)
	{
	memcpy(dst, src, sizeof(*dst));
	}
	EXPORT_SYMBOL(xxh64_copy_state);

	/-**************************
	* Simple Hash Functions
	****************************/
	static uint32_t xxh32_round(uint32_t seed, const uint32_t input)
	{
	seed += input * PRIME32_2;
	seed = xxh_rotl32(seed, 13);
	seed *= PRIME32_1;
	return seed;
	}

	uint32_t xxh32(const void *input, const size_t len, const uint32_t seed)
	{
	const uint8_t p = (const uint8_t )input;
	const uint8_t *b_end = p + len;
	uint32_t h32;

	if (len >= 16) {
	const uint8_t *const limit = b_end - 16;
	uint32_t v1 = seed + PRIME32_1 + PRIME32_2;
	uint32_t v2 = seed + PRIME32_2;
	uint32_t v3 = seed + 0;
	uint32_t v4 = seed - PRIME32_1;

	do {
	v1 = xxh32_round(v1, get_unaligned_le32(p));
	p += 4;
	v2 = xxh32_round(v2, get_unaligned_le32(p));
	p += 4;
	v3 = xxh32_round(v3, get_unaligned_le32(p));
	p += 4;
	v4 = xxh32_round(v4, get_unaligned_le32(p));
	p += 4;
	} while (p <= limit);

	h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) +
	xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18);
	} else {
	h32 = seed + PRIME32_5;
	}

	h32 += (uint32_t)len;

	while (p + 4 <= b_end) {
	h32 += get_unaligned_le32(p) * PRIME32_3;
	h32 = xxh_rotl32(h32, 17) * PRIME32_4;
	p += 4;
	}

	while (p < b_end) {
	h32 += (p) PRIME32_5;
	h32 = xxh_rotl32(h32, 11) * PRIME32_1;
	p++;
	}

	h32 ^= h32 >> 15;
	h32 *= PRIME32_2;
	h32 ^= h32 >> 13;
	h32 *= PRIME32_3;
	h32 ^= h32 >> 16;

	return h32;
	}
	EXPORT_SYMBOL(xxh32);

	static uint64_t xxh64_round(uint64_t acc, const uint64_t input)
	{
	acc += input * PRIME64_2;
	acc = xxh_rotl64(acc, 31);
	acc *= PRIME64_1;
	return acc;
	}

	static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val)
	{
	val = xxh64_round(0, val);
	acc ^= val;
	acc = acc * PRIME64_1 + PRIME64_4;
	return acc;
	}

	uint64_t xxh64(const void *input, const size_t len, const uint64_t seed)
	{
	const uint8_t p = (const uint8_t )input;
	const uint8_t *const b_end = p + len;
	uint64_t h64;

	if (len >= 32) {
	const uint8_t *const limit = b_end - 32;
	uint64_t v1 = seed + PRIME64_1 + PRIME64_2;
	uint64_t v2 = seed + PRIME64_2;
	uint64_t v3 = seed + 0;
	uint64_t v4 = seed - PRIME64_1;

	do {
	v1 = xxh64_round(v1, get_unaligned_le64(p));
	p += 8;
	v2 = xxh64_round(v2, get_unaligned_le64(p));
	p += 8;
	v3 = xxh64_round(v3, get_unaligned_le64(p));
	p += 8;
	v4 = xxh64_round(v4, get_unaligned_le64(p));
	p += 8;
	} while (p <= limit);

	h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
	xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
	h64 = xxh64_merge_round(h64, v1);
	h64 = xxh64_merge_round(h64, v2);
	h64 = xxh64_merge_round(h64, v3);
	h64 = xxh64_merge_round(h64, v4);

	} else {
	h64 = seed + PRIME64_5;
	}

	h64 += (uint64_t)len;

	while (p + 8 <= b_end) {
	const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));

	h64 ^= k1;
	h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
	p += 8;
	}

	if (p + 4 <= b_end) {
	h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
	h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
	p += 4;
	}

	while (p < b_end) {
	h64 ^= (p) PRIME64_5;
	h64 = xxh_rotl64(h64, 11) * PRIME64_1;
	p++;
	}

	h64 ^= h64 >> 33;
	h64 *= PRIME64_2;
	h64 ^= h64 >> 29;
	h64 *= PRIME64_3;
	h64 ^= h64 >> 32;

	return h64;
	}
	EXPORT_SYMBOL(xxh64);

	/-*************************************************
	* Advanced Hash Functions
	***************************************************/
	void xxh32_reset(struct xxh32_state *statePtr, const uint32_t seed)
	{
	/* use a local state for memcpy() to avoid strict-aliasing warnings */
	struct xxh32_state state;

	memset(&state, 0, sizeof(state));
	state.v1 = seed + PRIME32_1 + PRIME32_2;
	state.v2 = seed + PRIME32_2;
	state.v3 = seed + 0;
	state.v4 = seed - PRIME32_1;
	memcpy(statePtr, &state, sizeof(state));
	}
	EXPORT_SYMBOL(xxh32_reset);

	void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed)
	{
	/* use a local state for memcpy() to avoid strict-aliasing warnings */
	struct xxh64_state state;

	memset(&state, 0, sizeof(state));
	state.v1 = seed + PRIME64_1 + PRIME64_2;
	state.v2 = seed + PRIME64_2;
	state.v3 = seed + 0;
	state.v4 = seed - PRIME64_1;
	memcpy(statePtr, &state, sizeof(state));
	}
	EXPORT_SYMBOL(xxh64_reset);

	int xxh32_update(struct xxh32_state state, const void input, const size_t len)
	{
	const uint8_t p = (const uint8_t )input;
	const uint8_t *const b_end = p + len;

	if (input == NULL)
	return -EINVAL;

	state->total_len_32 += (uint32_t)len;
	state->large_len \|= (len >= 16) \| (state->total_len_32 >= 16);

	if (state->memsize + len < 16) { /* fill in tmp buffer */
	memcpy((uint8_t *)(state->mem32) + state->memsize, input, len);
	state->memsize += (uint32_t)len;
	return 0;
	}

	if (state->memsize) { /* some data left from previous update */
	const uint32_t *p32 = state->mem32;

	memcpy((uint8_t *)(state->mem32) + state->memsize, input,
	16 - state->memsize);

	state->v1 = xxh32_round(state->v1, get_unaligned_le32(p32));
	p32++;
	state->v2 = xxh32_round(state->v2, get_unaligned_le32(p32));
	p32++;
	state->v3 = xxh32_round(state->v3, get_unaligned_le32(p32));
	p32++;
	state->v4 = xxh32_round(state->v4, get_unaligned_le32(p32));
	p32++;

	p += 16-state->memsize;
	state->memsize = 0;
	}

	if (p <= b_end - 16) {
	const uint8_t *const limit = b_end - 16;
	uint32_t v1 = state->v1;
	uint32_t v2 = state->v2;
	uint32_t v3 = state->v3;
	uint32_t v4 = state->v4;

	do {
	v1 = xxh32_round(v1, get_unaligned_le32(p));
	p += 4;
	v2 = xxh32_round(v2, get_unaligned_le32(p));
	p += 4;
	v3 = xxh32_round(v3, get_unaligned_le32(p));
	p += 4;
	v4 = xxh32_round(v4, get_unaligned_le32(p));
	p += 4;
	} while (p <= limit);

	state->v1 = v1;
	state->v2 = v2;
	state->v3 = v3;
	state->v4 = v4;
	}

	if (p < b_end) {
	memcpy(state->mem32, p, (size_t)(b_end-p));
	state->memsize = (uint32_t)(b_end-p);
	}

	return 0;
	}
	EXPORT_SYMBOL(xxh32_update);

	uint32_t xxh32_digest(const struct xxh32_state *state)
	{
	const uint8_t p = (const uint8_t )state->mem32;
	const uint8_t const b_end = (const uint8_t )(state->mem32) +
	state->memsize;
	uint32_t h32;

	if (state->large_len) {
	h32 = xxh_rotl32(state->v1, 1) + xxh_rotl32(state->v2, 7) +
	xxh_rotl32(state->v3, 12) + xxh_rotl32(state->v4, 18);
	} else {
	h32 = state->v3 /* == seed */ + PRIME32_5;
	}

	h32 += state->total_len_32;

	while (p + 4 <= b_end) {
	h32 += get_unaligned_le32(p) * PRIME32_3;
	h32 = xxh_rotl32(h32, 17) * PRIME32_4;
	p += 4;
	}

	while (p < b_end) {
	h32 += (p) PRIME32_5;
	h32 = xxh_rotl32(h32, 11) * PRIME32_1;
	p++;
	}

	h32 ^= h32 >> 15;
	h32 *= PRIME32_2;
	h32 ^= h32 >> 13;
	h32 *= PRIME32_3;
	h32 ^= h32 >> 16;

	return h32;
	}
	EXPORT_SYMBOL(xxh32_digest);

	int xxh64_update(struct xxh64_state state, const void input, const size_t len)
	{
	const uint8_t p = (const uint8_t )input;
	const uint8_t *const b_end = p + len;

	if (input == NULL)
	return -EINVAL;

	state->total_len += len;

	if (state->memsize + len < 32) { /* fill in tmp buffer */
	memcpy(((uint8_t *)state->mem64) + state->memsize, input, len);
	state->memsize += (uint32_t)len;
	return 0;
	}

	if (state->memsize) { /* tmp buffer is full */
	uint64_t *p64 = state->mem64;

	memcpy(((uint8_t *)p64) + state->memsize, input,
	32 - state->memsize);

	state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64));
	p64++;
	state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64));
	p64++;
	state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64));
	p64++;
	state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64));

	p += 32 - state->memsize;
	state->memsize = 0;
	}

	if (p + 32 <= b_end) {
	const uint8_t *const limit = b_end - 32;
	uint64_t v1 = state->v1;
	uint64_t v2 = state->v2;
	uint64_t v3 = state->v3;
	uint64_t v4 = state->v4;

	do {
	v1 = xxh64_round(v1, get_unaligned_le64(p));
	p += 8;
	v2 = xxh64_round(v2, get_unaligned_le64(p));
	p += 8;
	v3 = xxh64_round(v3, get_unaligned_le64(p));
	p += 8;
	v4 = xxh64_round(v4, get_unaligned_le64(p));
	p += 8;
	} while (p <= limit);

	state->v1 = v1;
	state->v2 = v2;
	state->v3 = v3;
	state->v4 = v4;
	}

	if (p < b_end) {
	memcpy(state->mem64, p, (size_t)(b_end-p));
	state->memsize = (uint32_t)(b_end - p);
	}

	return 0;
	}
	EXPORT_SYMBOL(xxh64_update);

	uint64_t xxh64_digest(const struct xxh64_state *state)
	{
	const uint8_t p = (const uint8_t )state->mem64;
	const uint8_t const b_end = (const uint8_t )state->mem64 +
	state->memsize;
	uint64_t h64;

	if (state->total_len >= 32) {
	const uint64_t v1 = state->v1;
	const uint64_t v2 = state->v2;
	const uint64_t v3 = state->v3;
	const uint64_t v4 = state->v4;

	h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
	xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
	h64 = xxh64_merge_round(h64, v1);
	h64 = xxh64_merge_round(h64, v2);
	h64 = xxh64_merge_round(h64, v3);
	h64 = xxh64_merge_round(h64, v4);
	} else {
	h64 = state->v3 + PRIME64_5;
	}

	h64 += (uint64_t)state->total_len;

	while (p + 8 <= b_end) {
	const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));

	h64 ^= k1;
	h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
	p += 8;
	}

	if (p + 4 <= b_end) {
	h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
	h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
	p += 4;
	}

	while (p < b_end) {
	h64 ^= (p) PRIME64_5;
	h64 = xxh_rotl64(h64, 11) * PRIME64_1;
	p++;
	}

	h64 ^= h64 >> 33;
	h64 *= PRIME64_2;
	h64 ^= h64 >> 29;
	h64 *= PRIME64_3;
	h64 ^= h64 >> 32;

	return h64;
	}
	EXPORT_SYMBOL(xxh64_digest);

	MODULE_LICENSE("Dual BSD/GPL");
	MODULE_DESCRIPTION("xxHash");