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authorVincent Ambo <mail@tazj.in>2022-02-07T23·05+0300
committerclbot <clbot@tvl.fyi>2022-02-07T23·09+0000
commit5aa5d282eac56a21e74611c1cdbaa97bb5db2dca (patch)
tree8cc5dce8157a1470ff76719dd15d65f648a05522 /third_party/abseil_cpp/absl/hash/internal/city.cc
parenta25675804c4f429fab5ee5201fe25e89865dfd13 (diff)
chore(3p/abseil_cpp): unvendor abseil_cpp r/3786
we weren't actually using these sources anymore, okay?

Change-Id: If701571d9716de308d3512e1eb22c35db0877a66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5248
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Diffstat (limited to 'third_party/abseil_cpp/absl/hash/internal/city.cc')
-rw-r--r--third_party/abseil_cpp/absl/hash/internal/city.cc349
1 files changed, 0 insertions, 349 deletions
diff --git a/third_party/abseil_cpp/absl/hash/internal/city.cc b/third_party/abseil_cpp/absl/hash/internal/city.cc
deleted file mode 100644
index 5460134e5762..000000000000
--- a/third_party/abseil_cpp/absl/hash/internal/city.cc
+++ /dev/null
@@ -1,349 +0,0 @@
-// Copyright 2018 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// This file provides CityHash64() and related functions.
-//
-// It's probably possible to create even faster hash functions by
-// writing a program that systematically explores some of the space of
-// possible hash functions, by using SIMD instructions, or by
-// compromising on hash quality.
-
-#include "absl/hash/internal/city.h"
-
-#include <string.h>  // for memcpy and memset
-#include <algorithm>
-
-#include "absl/base/config.h"
-#include "absl/base/internal/endian.h"
-#include "absl/base/internal/unaligned_access.h"
-#include "absl/base/optimization.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace hash_internal {
-
-#ifdef ABSL_IS_BIG_ENDIAN
-#define uint32_in_expected_order(x) (absl::gbswap_32(x))
-#define uint64_in_expected_order(x) (absl::gbswap_64(x))
-#else
-#define uint32_in_expected_order(x) (x)
-#define uint64_in_expected_order(x) (x)
-#endif
-
-static uint64_t Fetch64(const char *p) {
-  return uint64_in_expected_order(ABSL_INTERNAL_UNALIGNED_LOAD64(p));
-}
-
-static uint32_t Fetch32(const char *p) {
-  return uint32_in_expected_order(ABSL_INTERNAL_UNALIGNED_LOAD32(p));
-}
-
-// Some primes between 2^63 and 2^64 for various uses.
-static const uint64_t k0 = 0xc3a5c85c97cb3127ULL;
-static const uint64_t k1 = 0xb492b66fbe98f273ULL;
-static const uint64_t k2 = 0x9ae16a3b2f90404fULL;
-
-// Magic numbers for 32-bit hashing.  Copied from Murmur3.
-static const uint32_t c1 = 0xcc9e2d51;
-static const uint32_t c2 = 0x1b873593;
-
-// A 32-bit to 32-bit integer hash copied from Murmur3.
-static uint32_t fmix(uint32_t h) {
-  h ^= h >> 16;
-  h *= 0x85ebca6b;
-  h ^= h >> 13;
-  h *= 0xc2b2ae35;
-  h ^= h >> 16;
-  return h;
-}
-
-static uint32_t Rotate32(uint32_t val, int shift) {
-  // Avoid shifting by 32: doing so yields an undefined result.
-  return shift == 0 ? val : ((val >> shift) | (val << (32 - shift)));
-}
-
-#undef PERMUTE3
-#define PERMUTE3(a, b, c) \
-  do {                    \
-    std::swap(a, b);      \
-    std::swap(a, c);      \
-  } while (0)
-
-static uint32_t Mur(uint32_t a, uint32_t h) {
-  // Helper from Murmur3 for combining two 32-bit values.
-  a *= c1;
-  a = Rotate32(a, 17);
-  a *= c2;
-  h ^= a;
-  h = Rotate32(h, 19);
-  return h * 5 + 0xe6546b64;
-}
-
-static uint32_t Hash32Len13to24(const char *s, size_t len) {
-  uint32_t a = Fetch32(s - 4 + (len >> 1));
-  uint32_t b = Fetch32(s + 4);
-  uint32_t c = Fetch32(s + len - 8);
-  uint32_t d = Fetch32(s + (len >> 1));
-  uint32_t e = Fetch32(s);
-  uint32_t f = Fetch32(s + len - 4);
-  uint32_t h = len;
-
-  return fmix(Mur(f, Mur(e, Mur(d, Mur(c, Mur(b, Mur(a, h)))))));
-}
-
-static uint32_t Hash32Len0to4(const char *s, size_t len) {
-  uint32_t b = 0;
-  uint32_t c = 9;
-  for (size_t i = 0; i < len; i++) {
-    signed char v = s[i];
-    b = b * c1 + v;
-    c ^= b;
-  }
-  return fmix(Mur(b, Mur(len, c)));
-}
-
-static uint32_t Hash32Len5to12(const char *s, size_t len) {
-  uint32_t a = len, b = len * 5, c = 9, d = b;
-  a += Fetch32(s);
-  b += Fetch32(s + len - 4);
-  c += Fetch32(s + ((len >> 1) & 4));
-  return fmix(Mur(c, Mur(b, Mur(a, d))));
-}
-
-uint32_t CityHash32(const char *s, size_t len) {
-  if (len <= 24) {
-    return len <= 12
-               ? (len <= 4 ? Hash32Len0to4(s, len) : Hash32Len5to12(s, len))
-               : Hash32Len13to24(s, len);
-  }
-
-  // len > 24
-  uint32_t h = len, g = c1 * len, f = g;
-
-  uint32_t a0 = Rotate32(Fetch32(s + len - 4) * c1, 17) * c2;
-  uint32_t a1 = Rotate32(Fetch32(s + len - 8) * c1, 17) * c2;
-  uint32_t a2 = Rotate32(Fetch32(s + len - 16) * c1, 17) * c2;
-  uint32_t a3 = Rotate32(Fetch32(s + len - 12) * c1, 17) * c2;
-  uint32_t a4 = Rotate32(Fetch32(s + len - 20) * c1, 17) * c2;
-  h ^= a0;
-  h = Rotate32(h, 19);
-  h = h * 5 + 0xe6546b64;
-  h ^= a2;
-  h = Rotate32(h, 19);
-  h = h * 5 + 0xe6546b64;
-  g ^= a1;
-  g = Rotate32(g, 19);
-  g = g * 5 + 0xe6546b64;
-  g ^= a3;
-  g = Rotate32(g, 19);
-  g = g * 5 + 0xe6546b64;
-  f += a4;
-  f = Rotate32(f, 19);
-  f = f * 5 + 0xe6546b64;
-  size_t iters = (len - 1) / 20;
-  do {
-    uint32_t b0 = Rotate32(Fetch32(s) * c1, 17) * c2;
-    uint32_t b1 = Fetch32(s + 4);
-    uint32_t b2 = Rotate32(Fetch32(s + 8) * c1, 17) * c2;
-    uint32_t b3 = Rotate32(Fetch32(s + 12) * c1, 17) * c2;
-    uint32_t b4 = Fetch32(s + 16);
-    h ^= b0;
-    h = Rotate32(h, 18);
-    h = h * 5 + 0xe6546b64;
-    f += b1;
-    f = Rotate32(f, 19);
-    f = f * c1;
-    g += b2;
-    g = Rotate32(g, 18);
-    g = g * 5 + 0xe6546b64;
-    h ^= b3 + b1;
-    h = Rotate32(h, 19);
-    h = h * 5 + 0xe6546b64;
-    g ^= b4;
-    g = absl::gbswap_32(g) * 5;
-    h += b4 * 5;
-    h = absl::gbswap_32(h);
-    f += b0;
-    PERMUTE3(f, h, g);
-    s += 20;
-  } while (--iters != 0);
-  g = Rotate32(g, 11) * c1;
-  g = Rotate32(g, 17) * c1;
-  f = Rotate32(f, 11) * c1;
-  f = Rotate32(f, 17) * c1;
-  h = Rotate32(h + g, 19);
-  h = h * 5 + 0xe6546b64;
-  h = Rotate32(h, 17) * c1;
-  h = Rotate32(h + f, 19);
-  h = h * 5 + 0xe6546b64;
-  h = Rotate32(h, 17) * c1;
-  return h;
-}
-
-// Bitwise right rotate.  Normally this will compile to a single
-// instruction, especially if the shift is a manifest constant.
-static uint64_t Rotate(uint64_t val, int shift) {
-  // Avoid shifting by 64: doing so yields an undefined result.
-  return shift == 0 ? val : ((val >> shift) | (val << (64 - shift)));
-}
-
-static uint64_t ShiftMix(uint64_t val) { return val ^ (val >> 47); }
-
-static uint64_t HashLen16(uint64_t u, uint64_t v, uint64_t mul) {
-  // Murmur-inspired hashing.
-  uint64_t a = (u ^ v) * mul;
-  a ^= (a >> 47);
-  uint64_t b = (v ^ a) * mul;
-  b ^= (b >> 47);
-  b *= mul;
-  return b;
-}
-
-static uint64_t HashLen16(uint64_t u, uint64_t v) {
-  const uint64_t kMul = 0x9ddfea08eb382d69ULL;
-  return HashLen16(u, v, kMul);
-}
-
-static uint64_t HashLen0to16(const char *s, size_t len) {
-  if (len >= 8) {
-    uint64_t mul = k2 + len * 2;
-    uint64_t a = Fetch64(s) + k2;
-    uint64_t b = Fetch64(s + len - 8);
-    uint64_t c = Rotate(b, 37) * mul + a;
-    uint64_t d = (Rotate(a, 25) + b) * mul;
-    return HashLen16(c, d, mul);
-  }
-  if (len >= 4) {
-    uint64_t mul = k2 + len * 2;
-    uint64_t a = Fetch32(s);
-    return HashLen16(len + (a << 3), Fetch32(s + len - 4), mul);
-  }
-  if (len > 0) {
-    uint8_t a = s[0];
-    uint8_t b = s[len >> 1];
-    uint8_t c = s[len - 1];
-    uint32_t y = static_cast<uint32_t>(a) + (static_cast<uint32_t>(b) << 8);
-    uint32_t z = len + (static_cast<uint32_t>(c) << 2);
-    return ShiftMix(y * k2 ^ z * k0) * k2;
-  }
-  return k2;
-}
-
-// This probably works well for 16-byte strings as well, but it may be overkill
-// in that case.
-static uint64_t HashLen17to32(const char *s, size_t len) {
-  uint64_t mul = k2 + len * 2;
-  uint64_t a = Fetch64(s) * k1;
-  uint64_t b = Fetch64(s + 8);
-  uint64_t c = Fetch64(s + len - 8) * mul;
-  uint64_t d = Fetch64(s + len - 16) * k2;
-  return HashLen16(Rotate(a + b, 43) + Rotate(c, 30) + d,
-                   a + Rotate(b + k2, 18) + c, mul);
-}
-
-// Return a 16-byte hash for 48 bytes.  Quick and dirty.
-// Callers do best to use "random-looking" values for a and b.
-static std::pair<uint64_t, uint64_t> WeakHashLen32WithSeeds(
-    uint64_t w, uint64_t x, uint64_t y, uint64_t z, uint64_t a, uint64_t b) {
-  a += w;
-  b = Rotate(b + a + z, 21);
-  uint64_t c = a;
-  a += x;
-  a += y;
-  b += Rotate(a, 44);
-  return std::make_pair(a + z, b + c);
-}
-
-// Return a 16-byte hash for s[0] ... s[31], a, and b.  Quick and dirty.
-static std::pair<uint64_t, uint64_t> WeakHashLen32WithSeeds(const char *s,
-                                                            uint64_t a,
-                                                            uint64_t b) {
-  return WeakHashLen32WithSeeds(Fetch64(s), Fetch64(s + 8), Fetch64(s + 16),
-                                Fetch64(s + 24), a, b);
-}
-
-// Return an 8-byte hash for 33 to 64 bytes.
-static uint64_t HashLen33to64(const char *s, size_t len) {
-  uint64_t mul = k2 + len * 2;
-  uint64_t a = Fetch64(s) * k2;
-  uint64_t b = Fetch64(s + 8);
-  uint64_t c = Fetch64(s + len - 24);
-  uint64_t d = Fetch64(s + len - 32);
-  uint64_t e = Fetch64(s + 16) * k2;
-  uint64_t f = Fetch64(s + 24) * 9;
-  uint64_t g = Fetch64(s + len - 8);
-  uint64_t h = Fetch64(s + len - 16) * mul;
-  uint64_t u = Rotate(a + g, 43) + (Rotate(b, 30) + c) * 9;
-  uint64_t v = ((a + g) ^ d) + f + 1;
-  uint64_t w = absl::gbswap_64((u + v) * mul) + h;
-  uint64_t x = Rotate(e + f, 42) + c;
-  uint64_t y = (absl::gbswap_64((v + w) * mul) + g) * mul;
-  uint64_t z = e + f + c;
-  a = absl::gbswap_64((x + z) * mul + y) + b;
-  b = ShiftMix((z + a) * mul + d + h) * mul;
-  return b + x;
-}
-
-uint64_t CityHash64(const char *s, size_t len) {
-  if (len <= 32) {
-    if (len <= 16) {
-      return HashLen0to16(s, len);
-    } else {
-      return HashLen17to32(s, len);
-    }
-  } else if (len <= 64) {
-    return HashLen33to64(s, len);
-  }
-
-  // For strings over 64 bytes we hash the end first, and then as we
-  // loop we keep 56 bytes of state: v, w, x, y, and z.
-  uint64_t x = Fetch64(s + len - 40);
-  uint64_t y = Fetch64(s + len - 16) + Fetch64(s + len - 56);
-  uint64_t z = HashLen16(Fetch64(s + len - 48) + len, Fetch64(s + len - 24));
-  std::pair<uint64_t, uint64_t> v =
-      WeakHashLen32WithSeeds(s + len - 64, len, z);
-  std::pair<uint64_t, uint64_t> w =
-      WeakHashLen32WithSeeds(s + len - 32, y + k1, x);
-  x = x * k1 + Fetch64(s);
-
-  // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
-  len = (len - 1) & ~static_cast<size_t>(63);
-  do {
-    x = Rotate(x + y + v.first + Fetch64(s + 8), 37) * k1;
-    y = Rotate(y + v.second + Fetch64(s + 48), 42) * k1;
-    x ^= w.second;
-    y += v.first + Fetch64(s + 40);
-    z = Rotate(z + w.first, 33) * k1;
-    v = WeakHashLen32WithSeeds(s, v.second * k1, x + w.first);
-    w = WeakHashLen32WithSeeds(s + 32, z + w.second, y + Fetch64(s + 16));
-    std::swap(z, x);
-    s += 64;
-    len -= 64;
-  } while (len != 0);
-  return HashLen16(HashLen16(v.first, w.first) + ShiftMix(y) * k1 + z,
-                   HashLen16(v.second, w.second) + x);
-}
-
-uint64_t CityHash64WithSeed(const char *s, size_t len, uint64_t seed) {
-  return CityHash64WithSeeds(s, len, k2, seed);
-}
-
-uint64_t CityHash64WithSeeds(const char *s, size_t len, uint64_t seed0,
-                             uint64_t seed1) {
-  return HashLen16(CityHash64(s, len) - seed0, seed1);
-}
-
-}  // namespace hash_internal
-ABSL_NAMESPACE_END
-}  // namespace absl