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		283fc52ade
		
	
	
	
	
		
			
			Without hardware acceleration, a cryptographically strong algorithm is too expensive for pauth_computepac. Even with hardware accel, we are not currently expecting to link the linux-user binaries to any crypto libraries, and doing so would generally make the --static build fail. So choose XXH64 as a reasonably quick and decent hash. Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20210111235740.462469-2-richard.henderson@linaro.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
		
			
				
	
	
		
			221 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			221 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * xxHash - Fast Hash algorithm
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|  * Copyright (C) 2012-2016, Yann Collet
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|  *
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|  * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions are
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|  * met:
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|  *
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|  * + Redistributions of source code must retain the above copyright
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|  * notice, this list of conditions and the following disclaimer.
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|  * + Redistributions in binary form must reproduce the above
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|  * copyright notice, this list of conditions and the following disclaimer
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|  * in the documentation and/or other materials provided with the
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|  * distribution.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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|  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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|  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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|  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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|  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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|  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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|  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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|  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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|  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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|  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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|  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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|  *
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|  * You can contact the author at :
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|  * - xxHash source repository : https://github.com/Cyan4973/xxHash
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|  */
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| 
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| #ifndef QEMU_XXHASH_H
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| #define QEMU_XXHASH_H
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| 
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| #include "qemu/bitops.h"
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| 
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| #define PRIME32_1   2654435761U
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| #define PRIME32_2   2246822519U
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| #define PRIME32_3   3266489917U
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| #define PRIME32_4    668265263U
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| #define PRIME32_5    374761393U
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| 
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| #define QEMU_XXHASH_SEED 1
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| 
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| /*
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|  * xxhash32, customized for input variables that are not guaranteed to be
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|  * contiguous in memory.
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|  */
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| static inline uint32_t
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| qemu_xxhash7(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f, uint32_t g)
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| {
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|     uint32_t v1 = QEMU_XXHASH_SEED + PRIME32_1 + PRIME32_2;
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|     uint32_t v2 = QEMU_XXHASH_SEED + PRIME32_2;
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|     uint32_t v3 = QEMU_XXHASH_SEED + 0;
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|     uint32_t v4 = QEMU_XXHASH_SEED - PRIME32_1;
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|     uint32_t a = ab;
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|     uint32_t b = ab >> 32;
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|     uint32_t c = cd;
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|     uint32_t d = cd >> 32;
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|     uint32_t h32;
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| 
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|     v1 += a * PRIME32_2;
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|     v1 = rol32(v1, 13);
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|     v1 *= PRIME32_1;
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| 
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|     v2 += b * PRIME32_2;
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|     v2 = rol32(v2, 13);
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|     v2 *= PRIME32_1;
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| 
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|     v3 += c * PRIME32_2;
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|     v3 = rol32(v3, 13);
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|     v3 *= PRIME32_1;
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| 
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|     v4 += d * PRIME32_2;
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|     v4 = rol32(v4, 13);
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|     v4 *= PRIME32_1;
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| 
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|     h32 = rol32(v1, 1) + rol32(v2, 7) + rol32(v3, 12) + rol32(v4, 18);
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|     h32 += 28;
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| 
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|     h32 += e * PRIME32_3;
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|     h32  = rol32(h32, 17) * PRIME32_4;
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| 
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|     h32 += f * PRIME32_3;
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|     h32  = rol32(h32, 17) * PRIME32_4;
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| 
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|     h32 += g * PRIME32_3;
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|     h32  = rol32(h32, 17) * PRIME32_4;
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| 
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|     h32 ^= h32 >> 15;
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|     h32 *= PRIME32_2;
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|     h32 ^= h32 >> 13;
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|     h32 *= PRIME32_3;
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|     h32 ^= h32 >> 16;
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| 
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|     return h32;
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| }
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| 
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| static inline uint32_t qemu_xxhash2(uint64_t ab)
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| {
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|     return qemu_xxhash7(ab, 0, 0, 0, 0);
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| }
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| 
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| static inline uint32_t qemu_xxhash4(uint64_t ab, uint64_t cd)
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| {
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|     return qemu_xxhash7(ab, cd, 0, 0, 0);
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| }
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| 
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| static inline uint32_t qemu_xxhash5(uint64_t ab, uint64_t cd, uint32_t e)
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| {
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|     return qemu_xxhash7(ab, cd, e, 0, 0);
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| }
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| 
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| static inline uint32_t qemu_xxhash6(uint64_t ab, uint64_t cd, uint32_t e,
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|                                     uint32_t f)
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| {
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|     return qemu_xxhash7(ab, cd, e, f, 0);
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| }
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| 
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| /*
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|  * Component parts of the XXH64 algorithm from
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|  * https://github.com/Cyan4973/xxHash/blob/v0.8.0/xxhash.h
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|  *
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|  * The complete algorithm looks like
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|  *
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|  *  i = 0;
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|  *  if (len >= 32) {
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|  *      v1 = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
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|  *      v2 = seed + XXH_PRIME64_2;
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|  *      v3 = seed + 0;
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|  *      v4 = seed - XXH_PRIME64_1;
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|  *      do {
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|  *          v1 = XXH64_round(v1, get64bits(input + i));
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|  *          v2 = XXH64_round(v2, get64bits(input + i + 8));
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|  *          v3 = XXH64_round(v3, get64bits(input + i + 16));
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|  *          v4 = XXH64_round(v4, get64bits(input + i + 24));
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|  *      } while ((i += 32) <= len);
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|  *      h64 = XXH64_mergerounds(v1, v2, v3, v4);
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|  *  } else {
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|  *      h64 = seed + XXH_PRIME64_5;
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|  *  }
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|  *  h64 += len;
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|  *
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|  *  for (; i + 8 <= len; i += 8) {
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|  *      h64 ^= XXH64_round(0, get64bits(input + i));
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|  *      h64 = rol64(h64, 27) * XXH_PRIME64_1 + XXH_PRIME64_4;
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|  *  }
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|  *  for (; i + 4 <= len; i += 4) {
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|  *      h64 ^= get32bits(input + i) * PRIME64_1;
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|  *      h64 = rol64(h64, 23) * XXH_PRIME64_2 + XXH_PRIME64_3;
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|  *  }
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|  *  for (; i < len; i += 1) {
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|  *      h64 ^= get8bits(input + i) * XXH_PRIME64_5;
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|  *      h64 = rol64(h64, 11) * XXH_PRIME64_1;
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|  *  }
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|  *
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|  *  return XXH64_avalanche(h64)
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|  *
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|  * Exposing the pieces instead allows for simplified usage when
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|  * the length is a known constant and the inputs are in registers.
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|  */
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| #define XXH_PRIME64_1   0x9E3779B185EBCA87ULL
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| #define XXH_PRIME64_2   0xC2B2AE3D27D4EB4FULL
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| #define XXH_PRIME64_3   0x165667B19E3779F9ULL
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| #define XXH_PRIME64_4   0x85EBCA77C2B2AE63ULL
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| #define XXH_PRIME64_5   0x27D4EB2F165667C5ULL
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| 
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| static inline uint64_t XXH64_round(uint64_t acc, uint64_t input)
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| {
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|     return rol64(acc + input * XXH_PRIME64_2, 31) * XXH_PRIME64_1;
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| }
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| 
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| static inline uint64_t XXH64_mergeround(uint64_t acc, uint64_t val)
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| {
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|     return (acc ^ XXH64_round(0, val)) * XXH_PRIME64_1 + XXH_PRIME64_4;
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| }
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| 
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| static inline uint64_t XXH64_mergerounds(uint64_t v1, uint64_t v2,
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|                                          uint64_t v3, uint64_t v4)
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| {
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|     uint64_t h64;
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| 
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|     h64 = rol64(v1, 1) + rol64(v2, 7) + rol64(v3, 12) + rol64(v4, 18);
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|     h64 = XXH64_mergeround(h64, v1);
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|     h64 = XXH64_mergeround(h64, v2);
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|     h64 = XXH64_mergeround(h64, v3);
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|     h64 = XXH64_mergeround(h64, v4);
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| 
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|     return h64;
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| }
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| 
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| static inline uint64_t XXH64_avalanche(uint64_t h64)
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| {
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|     h64 ^= h64 >> 33;
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|     h64 *= XXH_PRIME64_2;
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|     h64 ^= h64 >> 29;
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|     h64 *= XXH_PRIME64_3;
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|     h64 ^= h64 >> 32;
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|     return h64;
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| }
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| 
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| static inline uint64_t qemu_xxhash64_4(uint64_t a, uint64_t b,
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|                                        uint64_t c, uint64_t d)
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| {
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|     uint64_t v1 = QEMU_XXHASH_SEED + XXH_PRIME64_1 + XXH_PRIME64_2;
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|     uint64_t v2 = QEMU_XXHASH_SEED + XXH_PRIME64_2;
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|     uint64_t v3 = QEMU_XXHASH_SEED + 0;
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|     uint64_t v4 = QEMU_XXHASH_SEED - XXH_PRIME64_1;
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| 
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|     v1 = XXH64_round(v1, a);
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|     v2 = XXH64_round(v2, b);
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|     v3 = XXH64_round(v3, c);
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|     v4 = XXH64_round(v4, d);
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| 
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|     return XXH64_avalanche(XXH64_mergerounds(v1, v2, v3, v4));
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| }
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| 
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| #endif /* QEMU_XXHASH_H */
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