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authorAbseil Team <absl-team@google.com>2018-10-10T19·31-0700
committerCJ Johnson <johnsoncj@google.com>2018-10-10T19·35-0400
commitf340f773edab951656b19b6f1a77c964a78ec4c2 (patch)
treec42bf7faf49fb2355661c9f39c40513bc1ff2697 /absl/hash/internal/city.cc
parent445998d7ac4e5d3c50411d377e3b50e960d2d6c2 (diff)
Export of internal Abseil changes.
--
906c47420646d510edd2479d5542c56f5fa31b65 by CJ Johnson <johnsoncj@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 216573923

--
74560d4afd2b605909e677c6fc3076049fb3010a by Eric Fiselier <ericwf@google.com>:

Avoid -Wformat-pedantic in benchmark.

PiperOrigin-RevId: 216523769

--
9bcc9da8b03e6d1ea43ee78931256c5541cb9686 by Eric Fiselier <ericwf@google.com>:

Delete unused CityHash functions.

PiperOrigin-RevId: 216464492

--
a42563b394c89fbb4c55cb5a6a5edbf96d271eea by Abseil Team <absl-team@google.com>:

Introduce new Abseil interfaces for converting between civil
times and absolute times.s

Deprecates absl::ConvertDateTime() and absl::FromDateTime().

PiperOrigin-RevId: 216424948

--
088e11235124267517d7f137854fa5554679c24f by Eric Fiselier <ericwf@google.com>:

Remove unneeded break statements in test.

PiperOrigin-RevId: 216403321
GitOrigin-RevId: 906c47420646d510edd2479d5542c56f5fa31b65
Change-Id: Idb44420be623e369c66f5a9c92bdc9ab46d3ec92
Diffstat (limited to 'absl/hash/internal/city.cc')
-rw-r--r--absl/hash/internal/city.cc246
1 files changed, 0 insertions, 246 deletions
diff --git a/absl/hash/internal/city.cc b/absl/hash/internal/city.cc
index 8f72dd1b7d0c..122906fab042 100644
--- a/absl/hash/internal/city.cc
+++ b/absl/hash/internal/city.cc
@@ -340,251 +340,5 @@ uint64_t CityHash64WithSeeds(const char *s, size_t len, uint64_t seed0,
   return HashLen16(CityHash64(s, len) - seed0, seed1);
 }
 
-// A subroutine for CityHash128().  Returns a decent 128-bit hash for strings
-// of any length representable in signed long.  Based on City and Murmur.
-static uint128 CityMurmur(const char *s, size_t len, uint128 seed) {
-  uint64_t a = Uint128Low64(seed);
-  uint64_t b = Uint128High64(seed);
-  uint64_t c = 0;
-  uint64_t d = 0;
-  int64_t l = len - 16;
-  if (l <= 0) {  // len <= 16
-    a = ShiftMix(a * k1) * k1;
-    c = b * k1 + HashLen0to16(s, len);
-    d = ShiftMix(a + (len >= 8 ? Fetch64(s) : c));
-  } else {  // len > 16
-    c = HashLen16(Fetch64(s + len - 8) + k1, a);
-    d = HashLen16(b + len, c + Fetch64(s + len - 16));
-    a += d;
-    do {
-      a ^= ShiftMix(Fetch64(s) * k1) * k1;
-      a *= k1;
-      b ^= a;
-      c ^= ShiftMix(Fetch64(s + 8) * k1) * k1;
-      c *= k1;
-      d ^= c;
-      s += 16;
-      l -= 16;
-    } while (l > 0);
-  }
-  a = HashLen16(a, c);
-  b = HashLen16(d, b);
-  return uint128(a ^ b, HashLen16(b, a));
-}
-
-uint128 CityHash128WithSeed(const char *s, size_t len, uint128 seed) {
-  if (len < 128) {
-    return CityMurmur(s, len, seed);
-  }
-
-  // We expect len >= 128 to be the common case.  Keep 56 bytes of state:
-  // v, w, x, y, and z.
-  std::pair<uint64_t, uint64_t> v, w;
-  uint64_t x = Uint128Low64(seed);
-  uint64_t y = Uint128High64(seed);
-  uint64_t z = len * k1;
-  v.first = Rotate(y ^ k1, 49) * k1 + Fetch64(s);
-  v.second = Rotate(v.first, 42) * k1 + Fetch64(s + 8);
-  w.first = Rotate(y + z, 35) * k1 + x;
-  w.second = Rotate(x + Fetch64(s + 88), 53) * k1;
-
-  // This is the same inner loop as CityHash64(), manually unrolled.
-  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;
-    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 -= 128;
-  } while (ABSL_PREDICT_TRUE(len >= 128));
-  x += Rotate(v.first + z, 49) * k0;
-  y = y * k0 + Rotate(w.second, 37);
-  z = z * k0 + Rotate(w.first, 27);
-  w.first *= 9;
-  v.first *= k0;
-  // If 0 < len < 128, hash up to 4 chunks of 32 bytes each from the end of s.
-  for (size_t tail_done = 0; tail_done < len;) {
-    tail_done += 32;
-    y = Rotate(x + y, 42) * k0 + v.second;
-    w.first += Fetch64(s + len - tail_done + 16);
-    x = x * k0 + w.first;
-    z += w.second + Fetch64(s + len - tail_done);
-    w.second += v.first;
-    v = WeakHashLen32WithSeeds(s + len - tail_done, v.first + z, v.second);
-    v.first *= k0;
-  }
-  // At this point our 56 bytes of state should contain more than
-  // enough information for a strong 128-bit hash.  We use two
-  // different 56-byte-to-8-byte hashes to get a 16-byte final result.
-  x = HashLen16(x, v.first);
-  y = HashLen16(y + z, w.first);
-  return uint128(HashLen16(x + v.second, w.second) + y,
-                 HashLen16(x + w.second, y + v.second));
-}
-
-uint128 CityHash128(const char *s, size_t len) {
-  return len >= 16
-             ? CityHash128WithSeed(s + 16, len - 16,
-                                   uint128(Fetch64(s), Fetch64(s + 8) + k0))
-             : CityHash128WithSeed(s, len, uint128(k0, k1));
-}
 }  // namespace hash_internal
 }  // namespace absl
-
-#ifdef __SSE4_2__
-#include <nmmintrin.h>
-#include "absl/hash/internal/city_crc.h"
-
-namespace absl {
-namespace hash_internal {
-
-// Requires len >= 240.
-static void CityHashCrc256Long(const char *s, size_t len, uint32_t seed,
-                               uint64_t *result) {
-  uint64_t a = Fetch64(s + 56) + k0;
-  uint64_t b = Fetch64(s + 96) + k0;
-  uint64_t c = result[0] = HashLen16(b, len);
-  uint64_t d = result[1] = Fetch64(s + 120) * k0 + len;
-  uint64_t e = Fetch64(s + 184) + seed;
-  uint64_t f = 0;
-  uint64_t g = 0;
-  uint64_t h = c + d;
-  uint64_t x = seed;
-  uint64_t y = 0;
-  uint64_t z = 0;
-
-  // 240 bytes of input per iter.
-  size_t iters = len / 240;
-  len -= iters * 240;
-  do {
-#undef CHUNK
-#define CHUNK(r)               \
-  PERMUTE3(x, z, y);           \
-  b += Fetch64(s);             \
-  c += Fetch64(s + 8);         \
-  d += Fetch64(s + 16);        \
-  e += Fetch64(s + 24);        \
-  f += Fetch64(s + 32);        \
-  a += b;                      \
-  h += f;                      \
-  b += c;                      \
-  f += d;                      \
-  g += e;                      \
-  e += z;                      \
-  g += x;                      \
-  z = _mm_crc32_u64(z, b + g); \
-  y = _mm_crc32_u64(y, e + h); \
-  x = _mm_crc32_u64(x, f + a); \
-  e = Rotate(e, r);            \
-  c += e;                      \
-  s += 40
-
-    CHUNK(0);
-    PERMUTE3(a, h, c);
-    CHUNK(33);
-    PERMUTE3(a, h, f);
-    CHUNK(0);
-    PERMUTE3(b, h, f);
-    CHUNK(42);
-    PERMUTE3(b, h, d);
-    CHUNK(0);
-    PERMUTE3(b, h, e);
-    CHUNK(33);
-    PERMUTE3(a, h, e);
-  } while (--iters > 0);
-
-  while (len >= 40) {
-    CHUNK(29);
-    e ^= Rotate(a, 20);
-    h += Rotate(b, 30);
-    g ^= Rotate(c, 40);
-    f += Rotate(d, 34);
-    PERMUTE3(c, h, g);
-    len -= 40;
-  }
-  if (len > 0) {
-    s = s + len - 40;
-    CHUNK(33);
-    e ^= Rotate(a, 43);
-    h += Rotate(b, 42);
-    g ^= Rotate(c, 41);
-    f += Rotate(d, 40);
-  }
-  result[0] ^= h;
-  result[1] ^= g;
-  g += h;
-  a = HashLen16(a, g + z);
-  x += y << 32;
-  b += x;
-  c = HashLen16(c, z) + h;
-  d = HashLen16(d, e + result[0]);
-  g += e;
-  h += HashLen16(x, f);
-  e = HashLen16(a, d) + g;
-  z = HashLen16(b, c) + a;
-  y = HashLen16(g, h) + c;
-  result[0] = e + z + y + x;
-  a = ShiftMix((a + y) * k0) * k0 + b;
-  result[1] += a + result[0];
-  a = ShiftMix(a * k0) * k0 + c;
-  result[2] = a + result[1];
-  a = ShiftMix((a + e) * k0) * k0;
-  result[3] = a + result[2];
-}
-
-// Requires len < 240.
-static void CityHashCrc256Short(const char *s, size_t len, uint64_t *result) {
-  char buf[240];
-  memcpy(buf, s, len);
-  memset(buf + len, 0, 240 - len);
-  CityHashCrc256Long(buf, 240, ~static_cast<uint32_t>(len), result);
-}
-
-void CityHashCrc256(const char *s, size_t len, uint64_t *result) {
-  if (ABSL_PREDICT_TRUE(len >= 240)) {
-    CityHashCrc256Long(s, len, 0, result);
-  } else {
-    CityHashCrc256Short(s, len, result);
-  }
-}
-
-uint128 CityHashCrc128WithSeed(const char *s, size_t len, uint128 seed) {
-  if (len <= 900) {
-    return CityHash128WithSeed(s, len, seed);
-  } else {
-    uint64_t result[4];
-    CityHashCrc256(s, len, result);
-    uint64_t u = Uint128High64(seed) + result[0];
-    uint64_t v = Uint128Low64(seed) + result[1];
-    return uint128(HashLen16(u, v + result[2]),
-                   HashLen16(Rotate(v, 32), u * k0 + result[3]));
-  }
-}
-
-uint128 CityHashCrc128(const char *s, size_t len) {
-  if (len <= 900) {
-    return CityHash128(s, len);
-  } else {
-    uint64_t result[4];
-    CityHashCrc256(s, len, result);
-    return uint128(result[2], result[3]);
-  }
-}
-
-}  // namespace hash_internal
-}  // namespace absl
-
-#endif