MurmurHash3.cpp

// @HEADER
// *****************************************************************************
//          Tpetra: Templated Linear Algebra Services Package
//
// Copyright 2008 NTESS and the Tpetra contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER
 
//-----------------------------------------------------------------------------
// MurmurHash3 was written by Austin Appleby, and is placed in the public
// domain. The author hereby disclaims copyright to this source code.
 
// Note - The x86 and x64 versions do _not_ produce the same results, as the
// algorithms are optimized for their respective platforms. You can still
// compile and run any of them on any platform, but your performance with the
// non-native version will be less than optimal.
 
#include "MurmurHash3.hpp"
 
//-----------------------------------------------------------------------------
// Platform-specific functions and macros
 
// Microsoft Visual Studio
#if defined(_MSC_VER)
 
#define FORCE_INLINE __forceinline
 
#include <stdlib.h>
 
#define ROTL32(x, y) _rotl(x, y)
#define ROTL64(x, y) _rotl64(x, y)
 
#define BIG_CONSTANT(x) (x)
 
// Other compilers
 
#else  // not defined(_MSC_VER)
 
namespace {  // anonymous
 
inline uint32_t rotl32(uint32_t x, int8_t r) {
  return (x << r) | (x >> (32 - r));
}
 
inline uint64_t rotl64(uint64_t x, int8_t r) {
  return (x << r) | (x >> (64 - r));
}
 
}  // namespace
 
#define ROTL32(x, y) rotl32(x, y)
#define ROTL64(x, y) rotl64(x, y)
 
#define BIG_CONSTANT(x) (x##LLU)
 
#endif  // !defined(_MSC_VER)
 
//-----------------------------------------------------------------------------
// Block read - if your platform needs to do endian-swapping or can only
// handle aligned reads, do the conversion here
 
#define GETBLOCK(lhs, p, i) \
  {                         \
    lhs = p[(i)];           \
  }
 
//-----------------------------------------------------------------------------
// Finalization mix - force all bits of a hash block to avalanche
 
#define FMIX_32(h)      \
  {                     \
    uint32_t t_h = (h); \
    t_h ^= t_h >> 16;   \
    t_h *= 0x85ebca6b;  \
    t_h ^= t_h >> 13;   \
    t_h *= 0xc2b2ae35;  \
    t_h ^= t_h >> 16;   \
    h = t_h;            \
  }
 
//----------
 
#define FMIX_64(k)                           \
  {                                          \
    uint64_t t_k = (k);                      \
    t_k ^= t_k >> 33;                        \
    t_k *= BIG_CONSTANT(0xff51afd7ed558ccd); \
    t_k ^= t_k >> 33;                        \
    t_k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53); \
    t_k ^= t_k >> 33;                        \
    k = t_k;                                 \
  }
 
//-----------------------------------------------------------------------------
 
namespace Tpetra {
namespace Details {
 
void MurmurHash3_x86_32(const void *key, int len,
                        uint32_t seed, void *out) {
  const uint8_t *data = (const uint8_t *)key;
  const int nblocks   = len / 4;
 
  uint32_t h1 = seed;
 
  const uint32_t c1 = 0xcc9e2d51;
  const uint32_t c2 = 0x1b873593;
 
  //----------
  // body
 
  const uint32_t *blocks = (const uint32_t *)(data + nblocks * 4);
 
  for (int i = -nblocks; i; i++) {
    uint32_t k1;
    GETBLOCK(k1, blocks, i);
 
    k1 *= c1;
    k1 = ROTL32(k1, 15);
    k1 *= c2;
 
    h1 ^= k1;
    h1 = ROTL32(h1, 13);
    h1 = h1 * 5 + 0xe6546b64;
  }
 
  //----------
  // tail
 
  const uint8_t *tail = (const uint8_t *)(data + nblocks * 4);
 
  uint32_t k1 = 0;
 
  switch (len & 3) {
    case 3: k1 ^= tail[2] << 16;
    case 2: k1 ^= tail[1] << 8;
    case 1:
      k1 ^= tail[0];
      k1 *= c1;
      k1 = ROTL32(k1, 15);
      k1 *= c2;
      h1 ^= k1;
  };
 
  //----------
  // finalization
 
  h1 ^= len;
 
  FMIX_32(h1);
 
  *(uint32_t *)out = h1;
}
 
//-----------------------------------------------------------------------------
 
void MurmurHash3_x86_128(const void *key, const int len,
                         uint32_t seed, void *out) {
  const uint8_t *data = (const uint8_t *)key;
  const int nblocks   = len / 16;
 
  uint32_t h1 = seed;
  uint32_t h2 = seed;
  uint32_t h3 = seed;
  uint32_t h4 = seed;
 
  const uint32_t c1 = 0x239b961b;
  const uint32_t c2 = 0xab0e9789;
  const uint32_t c3 = 0x38b34ae5;
  const uint32_t c4 = 0xa1e38b93;
 
  //----------
  // body
 
  const uint32_t *blocks = (const uint32_t *)(data + nblocks * 16);
 
  for (int i = -nblocks; i; i++) {
    uint32_t k1, k2, k3, k4;
    GETBLOCK(k1, blocks, i * 4 + 0);
    GETBLOCK(k2, blocks, i * 4 + 1);
    GETBLOCK(k3, blocks, i * 4 + 2);
    GETBLOCK(k4, blocks, i * 4 + 3);
 
    k1 *= c1;
    k1 = ROTL32(k1, 15);
    k1 *= c2;
    h1 ^= k1;
 
    h1 = ROTL32(h1, 19);
    h1 += h2;
    h1 = h1 * 5 + 0x561ccd1b;
 
    k2 *= c2;
    k2 = ROTL32(k2, 16);
    k2 *= c3;
    h2 ^= k2;
 
    h2 = ROTL32(h2, 17);
    h2 += h3;
    h2 = h2 * 5 + 0x0bcaa747;
 
    k3 *= c3;
    k3 = ROTL32(k3, 17);
    k3 *= c4;
    h3 ^= k3;
 
    h3 = ROTL32(h3, 15);
    h3 += h4;
    h3 = h3 * 5 + 0x96cd1c35;
 
    k4 *= c4;
    k4 = ROTL32(k4, 18);
    k4 *= c1;
    h4 ^= k4;
 
    h4 = ROTL32(h4, 13);
    h4 += h1;
    h4 = h4 * 5 + 0x32ac3b17;
  }
 
  //----------
  // tail
 
  const uint8_t *tail = (const uint8_t *)(data + nblocks * 16);
 
  uint32_t k1 = 0;
  uint32_t k2 = 0;
  uint32_t k3 = 0;
  uint32_t k4 = 0;
 
  switch (len & 15) {
    case 15: k4 ^= tail[14] << 16;
    case 14: k4 ^= tail[13] << 8;
    case 13:
      k4 ^= tail[12] << 0;
      k4 *= c4;
      k4 = ROTL32(k4, 18);
      k4 *= c1;
      h4 ^= k4;
 
    case 12: k3 ^= tail[11] << 24;
    case 11: k3 ^= tail[10] << 16;
    case 10: k3 ^= tail[9] << 8;
    case 9:
      k3 ^= tail[8] << 0;
      k3 *= c3;
      k3 = ROTL32(k3, 17);
      k3 *= c4;
      h3 ^= k3;
 
    case 8: k2 ^= tail[7] << 24;
    case 7: k2 ^= tail[6] << 16;
    case 6: k2 ^= tail[5] << 8;
    case 5:
      k2 ^= tail[4] << 0;
      k2 *= c2;
      k2 = ROTL32(k2, 16);
      k2 *= c3;
      h2 ^= k2;
 
    case 4: k1 ^= tail[3] << 24;
    case 3: k1 ^= tail[2] << 16;
    case 2: k1 ^= tail[1] << 8;
    case 1:
      k1 ^= tail[0] << 0;
      k1 *= c1;
      k1 = ROTL32(k1, 15);
      k1 *= c2;
      h1 ^= k1;
  };
 
  //----------
  // finalization
 
  h1 ^= len;
  h2 ^= len;
  h3 ^= len;
  h4 ^= len;
 
  h1 += h2;
  h1 += h3;
  h1 += h4;
  h2 += h1;
  h3 += h1;
  h4 += h1;
 
  FMIX_32(h1);
  FMIX_32(h2);
  FMIX_32(h3);
  FMIX_32(h4);
 
  h1 += h2;
  h1 += h3;
  h1 += h4;
  h2 += h1;
  h3 += h1;
  h4 += h1;
 
  ((uint32_t *)out)[0] = h1;
  ((uint32_t *)out)[1] = h2;
  ((uint32_t *)out)[2] = h3;
  ((uint32_t *)out)[3] = h4;
}
 
//-----------------------------------------------------------------------------
 
void MurmurHash3_x64_128(const void *key, const int len,
                         const uint32_t seed, void *out) {
  const uint8_t *data = (const uint8_t *)key;
  const int nblocks   = len / 16;
 
  uint64_t h1 = seed;
  uint64_t h2 = seed;
 
  const uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
  const uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
 
  //----------
  // body
 
  const uint64_t *blocks = (const uint64_t *)(data);
 
  for (int i = 0; i < nblocks; i++) {
    uint64_t k1, k2;
    GETBLOCK(k1, blocks, i * 2 + 0);
    GETBLOCK(k2, blocks, i * 2 + 1);
 
    k1 *= c1;
    k1 = ROTL64(k1, 31);
    k1 *= c2;
    h1 ^= k1;
 
    h1 = ROTL64(h1, 27);
    h1 += h2;
    h1 = h1 * 5 + 0x52dce729;
 
    k2 *= c2;
    k2 = ROTL64(k2, 33);
    k2 *= c1;
    h2 ^= k2;
 
    h2 = ROTL64(h2, 31);
    h2 += h1;
    h2 = h2 * 5 + 0x38495ab5;
  }
 
  //----------
  // tail
 
  const uint8_t *tail = (const uint8_t *)(data + nblocks * 16);
 
  uint64_t k1 = 0;
  uint64_t k2 = 0;
 
  switch (len & 15) {
    case 15: k2 ^= uint64_t(tail[14]) << 48;
    case 14: k2 ^= uint64_t(tail[13]) << 40;
    case 13: k2 ^= uint64_t(tail[12]) << 32;
    case 12: k2 ^= uint64_t(tail[11]) << 24;
    case 11: k2 ^= uint64_t(tail[10]) << 16;
    case 10: k2 ^= uint64_t(tail[9]) << 8;
    case 9:
      k2 ^= uint64_t(tail[8]) << 0;
      k2 *= c2;
      k2 = ROTL64(k2, 33);
      k2 *= c1;
      h2 ^= k2;
 
    case 8: k1 ^= uint64_t(tail[7]) << 56;
    case 7: k1 ^= uint64_t(tail[6]) << 48;
    case 6: k1 ^= uint64_t(tail[5]) << 40;
    case 5: k1 ^= uint64_t(tail[4]) << 32;
    case 4: k1 ^= uint64_t(tail[3]) << 24;
    case 3: k1 ^= uint64_t(tail[2]) << 16;
    case 2: k1 ^= uint64_t(tail[1]) << 8;
    case 1:
      k1 ^= uint64_t(tail[0]) << 0;
      k1 *= c1;
      k1 = ROTL64(k1, 31);
      k1 *= c2;
      h1 ^= k1;
  };
 
  //----------
  // finalization
 
  h1 ^= len;
  h2 ^= len;
 
  h1 += h2;
  h2 += h1;
 
  FMIX_64(h1);
  FMIX_64(h2);
 
  h1 += h2;
  h2 += h1;
 
  ((uint64_t *)out)[0] = h1;
  ((uint64_t *)out)[1] = h2;
}
 
}  // namespace Details
}  // namespace Tpetra
 
//-----------------------------------------------------------------------------