/*

*  xxHash - Fast Hash algorithm

*  Copyright (C) 2012-2021, 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.

*

*  You can contact the author at :

*  - xxHash homepage: http://www.xxhash.com

*  - xxHash source repository : https://github.com/Cyan4973/xxHash

*/

// xxhash64 is based on commit d2df04efcbef7d7f6886d345861e5dfda4edacc1. Removed

// everything but a simple interface for computing xxh64.

// xxh3_64bits is based on commit d5891596637d21366b9b1dcf2c0007a3edb26a9e (July

// 2023).

#include "llvm/Support/xxhash.h"

#include "llvm/Support/Compiler.h"

#include "llvm/Support/Endian.h"

#include <stdlib.h>

using namespace llvm;

using namespace support;

static uint64_t rotl64(uint64_t X, size_t R) {

  return (X << R) | (X >> (64 - R));

}

constexpr uint32_t PRIME32_1 = 0x9E3779B1;

constexpr uint32_t PRIME32_2 = 0x85EBCA77;

constexpr uint32_t PRIME32_3 = 0xC2B2AE3D;

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;

static uint64_t round(uint64_t Acc, uint64_t Input) {

  Acc += Input * PRIME64_2;

  Acc = rotl64(Acc, 31);

  Acc *= PRIME64_1;

  return Acc;

}

static uint64_t mergeRound(uint64_t Acc, uint64_t Val) {

  Val = round(0, Val);

  Acc ^= Val;

  Acc = Acc * PRIME64_1 + PRIME64_4;

  return Acc;

}

static uint64_t XXH64_avalanche(uint64_t hash) {

  hash ^= hash >> 33;

  hash *= PRIME64_2;

  hash ^= hash >> 29;

  hash *= PRIME64_3;

  hash ^= hash >> 32;

  return hash;

}

uint64_t llvm::xxHash64(StringRef Data) {

  size_t Len = Data.size();

  uint64_t Seed = 0;

  const unsigned char *P = Data.bytes_begin();

  const unsigned char *const BEnd = Data.bytes_end();

  uint64_t H64;

  if (Len >= 32) {

    const unsigned char *const Limit = BEnd - 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 = round(V1, endian::read64le(P));

      P += 8;

      V2 = round(V2, endian::read64le(P));

      P += 8;

      V3 = round(V3, endian::read64le(P));

      P += 8;

      V4 = round(V4, endian::read64le(P));

      P += 8;

    } while (P <= Limit);

    H64 = rotl64(V1, 1) + rotl64(V2, 7) + rotl64(V3, 12) + rotl64(V4, 18);

    H64 = mergeRound(H64, V1);

    H64 = mergeRound(H64, V2);

    H64 = mergeRound(H64, V3);

    H64 = mergeRound(H64, V4);

  } else {

    H64 = Seed + PRIME64_5;

  }

  H64 += (uint64_t)Len;

  while (reinterpret_cast<uintptr_t>(P) + 8 <=

         reinterpret_cast<uintptr_t>(BEnd)) {

    uint64_t const K1 = round(0, endian::read64le(P));

    H64 ^= K1;

    H64 = rotl64(H64, 27) * PRIME64_1 + PRIME64_4;

    P += 8;

  }

  if (reinterpret_cast<uintptr_t>(P) + 4 <= reinterpret_cast<uintptr_t>(BEnd)) {

    H64 ^= (uint64_t)(endian::read32le(P)) * PRIME64_1;

    H64 = rotl64(H64, 23) * PRIME64_2 + PRIME64_3;

    P += 4;

  }

  while (P < BEnd) {

    H64 ^= (*P) * PRIME64_5;

    H64 = rotl64(H64, 11) * PRIME64_1;

    P++;

  }

  return XXH64_avalanche(H64);

}

uint64_t llvm::xxHash64(ArrayRef<uint8_t> Data) {

  return xxHash64({(const char *)Data.data(), Data.size()});

}

constexpr size_t XXH3_SECRETSIZE_MIN = 136;

constexpr size_t XXH_SECRET_DEFAULT_SIZE = 192;

/* Pseudorandom data taken directly from FARSH */

// clang-format off

constexpr uint8_t kSecret[XXH_SECRET_DEFAULT_SIZE] = {

    0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c,

    0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f,

    0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,

    0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c,

    0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3,

    0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,

    0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d,

    0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64,

    0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,

    0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e,

    0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce,

    0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,

};

// clang-format on

constexpr uint64_t PRIME_MX1 = 0x165667919E3779F9;

constexpr uint64_t PRIME_MX2 = 0x9FB21C651E98DF25;

// Calculates a 64-bit to 128-bit multiply, then XOR folds it.

static uint64_t XXH3_mul128_fold64(uint64_t lhs, uint64_t rhs) {

#if defined(__SIZEOF_INT128__) ||                                              \

    (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)

  __uint128_t product = (__uint128_t)lhs * (__uint128_t)rhs;

  return uint64_t(product) ^ uint64_t(product >> 64);

#else

  /* First calculate all of the cross products. */

  const uint64_t lo_lo = (lhs & 0xFFFFFFFF) * (rhs & 0xFFFFFFFF);

  const uint64_t hi_lo = (lhs >> 32) * (rhs & 0xFFFFFFFF);

  const uint64_t lo_hi = (lhs & 0xFFFFFFFF) * (rhs >> 32);

  const uint64_t hi_hi = (lhs >> 32) * (rhs >> 32);

  /* Now add the products together. These will never overflow. */

  const uint64_t cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi;

  const uint64_t upper = (hi_lo >> 32) + (cross >> 32) + hi_hi;

  const uint64_t lower = (cross << 32) | (lo_lo & 0xFFFFFFFF);

  return upper ^ lower;

#endif

}

constexpr size_t XXH_STRIPE_LEN = 64;

constexpr size_t XXH_SECRET_CONSUME_RATE = 8;

constexpr size_t XXH_ACC_NB = XXH_STRIPE_LEN / sizeof(uint64_t);

static uint64_t XXH3_avalanche(uint64_t hash) {

  hash ^= hash >> 37;

  hash *= PRIME_MX1;

  hash ^= hash >> 32;

  return hash;

}

static uint64_t XXH3_len_1to3_64b(const uint8_t *input, size_t len,

                                  const uint8_t *secret, uint64_t seed) {

  const uint8_t c1 = input[0];

  const uint8_t c2 = input[len >> 1];

  const uint8_t c3 = input[len - 1];

  uint32_t combined = ((uint32_t)c1 << 16) | ((uint32_t)c2 << 24) |

                      ((uint32_t)c3 << 0) | ((uint32_t)len << 8);

  uint64_t bitflip =

      (uint64_t)(endian::read32le(secret) ^ endian::read32le(secret + 4)) +

      seed;

  return XXH64_avalanche(uint64_t(combined) ^ bitflip);

}

static uint64_t XXH3_len_4to8_64b(const uint8_t *input, size_t len,

                                  const uint8_t *secret, uint64_t seed) {

  seed ^= (uint64_t)byteswap(uint32_t(seed)) << 32;

  const uint32_t input1 = endian::read32le(input);

  const uint32_t input2 = endian::read32le(input + len - 4);

  uint64_t acc =

      (endian::read64le(secret + 8) ^ endian::read64le(secret + 16)) - seed;

  const uint64_t input64 = (uint64_t)input2 | ((uint64_t)input1 << 32);

  acc ^= input64;

  // XXH3_rrmxmx(acc, len)

  acc ^= rotl64(acc, 49) ^ rotl64(acc, 24);

  acc *= PRIME_MX2;

  acc ^= (acc >> 35) + (uint64_t)len;

  acc *= PRIME_MX2;

  return acc ^ (acc >> 28);

}

static uint64_t XXH3_len_9to16_64b(const uint8_t *input, size_t len,

                                   const uint8_t *secret, uint64_t const seed) {

  uint64_t input_lo =

      (endian::read64le(secret + 24) ^ endian::read64le(secret + 32)) + seed;

  uint64_t input_hi =

      (endian::read64le(secret + 40) ^ endian::read64le(secret + 48)) - seed;

  input_lo ^= endian::read64le(input);

  input_hi ^= endian::read64le(input + len - 8);

  uint64_t acc = uint64_t(len) + byteswap(input_lo) + input_hi +

                 XXH3_mul128_fold64(input_lo, input_hi);

  return XXH3_avalanche(acc);

}

LLVM_ATTRIBUTE_ALWAYS_INLINE

static uint64_t XXH3_len_0to16_64b(const uint8_t *input, size_t len,

                                   const uint8_t *secret, uint64_t const seed) {

  if (LLVM_LIKELY(len > 8))

    return XXH3_len_9to16_64b(input, len, secret, seed);

  if (LLVM_LIKELY(len >= 4))

    return XXH3_len_4to8_64b(input, len, secret, seed);

  if (len != 0)

    return XXH3_len_1to3_64b(input, len, secret, seed);

  return XXH64_avalanche(seed ^ endian::read64le(secret + 56) ^

                         endian::read64le(secret + 64));

}

static uint64_t XXH3_mix16B(const uint8_t *input, uint8_t const *secret,

                            uint64_t seed) {

  uint64_t lhs = seed;

  uint64_t rhs = 0U - seed;

  lhs += endian::read64le(secret);

  rhs += endian::read64le(secret + 8);

  lhs ^= endian::read64le(input);

  rhs ^= endian::read64le(input + 8);

  return XXH3_mul128_fold64(lhs, rhs);

}

/* For mid range keys, XXH3 uses a Mum-hash variant. */

LLVM_ATTRIBUTE_ALWAYS_INLINE

static uint64_t XXH3_len_17to128_64b(const uint8_t *input, size_t len,

                                     const uint8_t *secret,

                                     uint64_t const seed) {

  uint64_t acc = len * PRIME64_1, acc_end;

  acc += XXH3_mix16B(input + 0, secret + 0, seed);

  acc_end = XXH3_mix16B(input + len - 16, secret + 16, seed);

  if (len > 32) {

    acc += XXH3_mix16B(input + 16, secret + 32, seed);

    acc_end += XXH3_mix16B(input + len - 32, secret + 48, seed);

    if (len > 64) {

      acc += XXH3_mix16B(input + 32, secret + 64, seed);

      acc_end += XXH3_mix16B(input + len - 48, secret + 80, seed);

      if (len > 96) {

        acc += XXH3_mix16B(input + 48, secret + 96, seed);

        acc_end += XXH3_mix16B(input + len - 64, secret + 112, seed);

      }

    }

  }

  return XXH3_avalanche(acc + acc_end);

}

constexpr size_t XXH3_MIDSIZE_MAX = 240;

LLVM_ATTRIBUTE_NOINLINE

static uint64_t XXH3_len_129to240_64b(const uint8_t *input, size_t len,

                                      const uint8_t *secret, uint64_t seed) {

  constexpr size_t XXH3_MIDSIZE_STARTOFFSET = 3;

  constexpr size_t XXH3_MIDSIZE_LASTOFFSET = 17;

  uint64_t acc = (uint64_t)len * PRIME64_1;

  const unsigned nbRounds = len / 16;

  for (unsigned i = 0; i < 8; ++i)

    acc += XXH3_mix16B(input + 16 * i, secret + 16 * i, seed);

  acc = XXH3_avalanche(acc);

  for (unsigned i = 8; i < nbRounds; ++i) {

    acc += XXH3_mix16B(input + 16 * i,

                       secret + 16 * (i - 8) + XXH3_MIDSIZE_STARTOFFSET, seed);

  }

  /* last bytes */

  acc +=

      XXH3_mix16B(input + len - 16,

                  secret + XXH3_SECRETSIZE_MIN - XXH3_MIDSIZE_LASTOFFSET, seed);

  return XXH3_avalanche(acc);

}

LLVM_ATTRIBUTE_ALWAYS_INLINE

static void XXH3_accumulate_512_scalar(uint64_t *acc, const uint8_t *input,

                                       const uint8_t *secret) {

  for (size_t i = 0; i < XXH_ACC_NB; ++i) {

    uint64_t data_val = endian::read64le(input + 8 * i);

    uint64_t data_key = data_val ^ endian::read64le(secret + 8 * i);

    acc[i ^ 1] += data_val;

    acc[i] += uint32_t(data_key) * (data_key >> 32);

  }

}

LLVM_ATTRIBUTE_ALWAYS_INLINE

static void XXH3_accumulate_scalar(uint64_t *acc, const uint8_t *input,

                                   const uint8_t *secret, size_t nbStripes) {

  for (size_t n = 0; n < nbStripes; ++n)

    XXH3_accumulate_512_scalar(acc, input + n * XXH_STRIPE_LEN,

                               secret + n * XXH_SECRET_CONSUME_RATE);

}

static void XXH3_scrambleAcc(uint64_t *acc, const uint8_t *secret) {

  for (size_t i = 0; i < XXH_ACC_NB; ++i) {

    acc[i] ^= acc[i] >> 47;

    acc[i] ^= endian::read64le(secret + 8 * i);

    acc[i] *= PRIME32_1;

  }

}

static uint64_t XXH3_mix2Accs(const uint64_t *acc, const uint8_t *secret) {

  return XXH3_mul128_fold64(acc[0] ^ endian::read64le(secret),

                            acc[1] ^ endian::read64le(secret + 8));

}

static uint64_t XXH3_mergeAccs(const uint64_t *acc, const uint8_t *key,

                               uint64_t start) {

  uint64_t result64 = start;

  for (size_t i = 0; i < 4; ++i)

    result64 += XXH3_mix2Accs(acc + 2 * i, key + 16 * i);

  return XXH3_avalanche(result64);

}

LLVM_ATTRIBUTE_NOINLINE

static uint64_t XXH3_hashLong_64b(const uint8_t *input, size_t len,

                                  const uint8_t *secret, size_t secretSize) {

  const size_t nbStripesPerBlock =

      (secretSize - XXH_STRIPE_LEN) / XXH_SECRET_CONSUME_RATE;

  const size_t block_len = XXH_STRIPE_LEN * nbStripesPerBlock;

  const size_t nb_blocks = (len - 1) / block_len;

  alignas(16) uint64_t acc[XXH_ACC_NB] = {

      PRIME32_3, PRIME64_1, PRIME64_2, PRIME64_3,

      PRIME64_4, PRIME32_2, PRIME64_5, PRIME32_1,

  };

  for (size_t n = 0; n < nb_blocks; ++n) {

    XXH3_accumulate_scalar(acc, input + n * block_len, secret,

                           nbStripesPerBlock);

    XXH3_scrambleAcc(acc, secret + secretSize - XXH_STRIPE_LEN);

  }

  /* last partial block */

  const size_t nbStripes = (len - 1 - (block_len * nb_blocks)) / XXH_STRIPE_LEN;

  assert(nbStripes <= secretSize / XXH_SECRET_CONSUME_RATE);

  XXH3_accumulate_scalar(acc, input + nb_blocks * block_len, secret, nbStripes);

  /* last stripe */

  constexpr size_t XXH_SECRET_LASTACC_START = 7;

  XXH3_accumulate_512_scalar(acc, input + len - XXH_STRIPE_LEN,

                             secret + secretSize - XXH_STRIPE_LEN -

                                 XXH_SECRET_LASTACC_START);

  /* converge into final hash */

  constexpr size_t XXH_SECRET_MERGEACCS_START = 11;

  return XXH3_mergeAccs(acc, secret + XXH_SECRET_MERGEACCS_START,

                        (uint64_t)len * PRIME64_1);

}

uint64_t llvm::xxh3_64bits(ArrayRef<uint8_t> data) {

  auto *in = data.data();

  size_t len = data.size();

  if (len <= 16)

    return XXH3_len_0to16_64b(in, len, kSecret, 0);

  if (len <= 128)

    return XXH3_len_17to128_64b(in, len, kSecret, 0);

  if (len <= XXH3_MIDSIZE_MAX)

    return XXH3_len_129to240_64b(in, len, kSecret, 0);

  return XXH3_hashLong_64b(in, len, kSecret, sizeof(kSecret));

}