include/exec/tb-hash-xx.h

   1 /*
   2  * xxHash - Fast Hash algorithm
   3  * Copyright (C) 2012-2016, Yann Collet
   4  *
   5  * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions are
   9  * met:
  10  *
  11  * + Redistributions of source code must retain the above copyright
  12  * notice, this list of conditions and the following disclaimer.
  13  * + Redistributions in binary form must reproduce the above
  14  * copyright notice, this list of conditions and the following disclaimer
  15  * in the documentation and/or other materials provided with the
  16  * distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * You can contact the author at :
  31  * - xxHash source repository : https://github.com/Cyan4973/xxHash
  32  */
  33 #ifndef EXEC_TB_HASH_XX
  34 #define EXEC_TB_HASH_XX
  35
  36 #include <qemu/bitops.h>
  37
  38 #define PRIME32_1   2654435761U
  39 #define PRIME32_2   2246822519U
  40 #define PRIME32_3   3266489917U
  41 #define PRIME32_4    668265263U
  42 #define PRIME32_5    374761393U
  43
  44 #define TB_HASH_XX_SEED 1
  45
  46 /*
  47  * xxhash32, customized for input variables that are not guaranteed to be
  48  * contiguous in memory.
  49  */
  50 static inline
  51 uint32_t tb_hash_func5(uint64_t a0, uint64_t b0, uint32_t e)
  52 {
  53     uint32_t v1 = TB_HASH_XX_SEED + PRIME32_1 + PRIME32_2;
  54     uint32_t v2 = TB_HASH_XX_SEED + PRIME32_2;
  55     uint32_t v3 = TB_HASH_XX_SEED + 0;
  56     uint32_t v4 = TB_HASH_XX_SEED - PRIME32_1;
  57     uint32_t a = a0 >> 32;
  58     uint32_t b = a0;
  59     uint32_t c = b0 >> 32;
  60     uint32_t d = b0;
  61     uint32_t h32;
  62
  63     v1 += a * PRIME32_2;
  64     v1 = rol32(v1, 13);
  65     v1 *= PRIME32_1;
  66
  67     v2 += b * PRIME32_2;
  68     v2 = rol32(v2, 13);
  69     v2 *= PRIME32_1;
  70
  71     v3 += c * PRIME32_2;
  72     v3 = rol32(v3, 13);
  73     v3 *= PRIME32_1;
  74
  75     v4 += d * PRIME32_2;
  76     v4 = rol32(v4, 13);
  77     v4 *= PRIME32_1;
  78
  79     h32 = rol32(v1, 1) + rol32(v2, 7) + rol32(v3, 12) + rol32(v4, 18);
  80     h32 += 20;
  81
  82     h32 += e * PRIME32_3;
  83     h32  = rol32(h32, 17) * PRIME32_4;
  84
  85     h32 ^= h32 >> 15;
  86     h32 *= PRIME32_2;
  87     h32 ^= h32 >> 13;
  88     h32 *= PRIME32_3;
  89     h32 ^= h32 >> 16;
  90
  91     return h32;
  92 }
  93
  94 #endif /* EXEC_TB_HASH_XX */