diff options
Diffstat (limited to 'absl/hash')
-rw-r--r-- | absl/hash/internal/city.cc | 9 | ||||
-rw-r--r-- | absl/hash/internal/city.h | 18 |
2 files changed, 5 insertions, 22 deletions
diff --git a/absl/hash/internal/city.cc b/absl/hash/internal/city.cc index 58d4bcb1..5460134e 100644 --- a/absl/hash/internal/city.cc +++ b/absl/hash/internal/city.cc @@ -200,10 +200,6 @@ static uint64_t Rotate(uint64_t val, int shift) { static uint64_t ShiftMix(uint64_t val) { return val ^ (val >> 47); } -static uint64_t HashLen16(uint64_t u, uint64_t v) { - return Hash128to64(uint128(u, v)); -} - static uint64_t HashLen16(uint64_t u, uint64_t v, uint64_t mul) { // Murmur-inspired hashing. uint64_t a = (u ^ v) * mul; @@ -214,6 +210,11 @@ static uint64_t HashLen16(uint64_t u, uint64_t v, uint64_t 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; diff --git a/absl/hash/internal/city.h b/absl/hash/internal/city.h index 9c1e7a57..393da0b9 100644 --- a/absl/hash/internal/city.h +++ b/absl/hash/internal/city.h @@ -56,11 +56,6 @@ namespace absl { ABSL_NAMESPACE_BEGIN namespace hash_internal { -typedef std::pair<uint64_t, uint64_t> uint128; - -inline uint64_t Uint128Low64(const uint128 &x) { return x.first; } -inline uint64_t Uint128High64(const uint128 &x) { return x.second; } - // Hash function for a byte array. uint64_t CityHash64(const char *s, size_t len); @@ -76,19 +71,6 @@ uint64_t CityHash64WithSeeds(const char *s, size_t len, uint64_t seed0, // Hash function for a byte array. Most useful in 32-bit binaries. uint32_t CityHash32(const char *s, size_t len); -// Hash 128 input bits down to 64 bits of output. -// This is intended to be a reasonably good hash function. -inline uint64_t Hash128to64(const uint128 &x) { - // Murmur-inspired hashing. - const uint64_t kMul = 0x9ddfea08eb382d69ULL; - uint64_t a = (Uint128Low64(x) ^ Uint128High64(x)) * kMul; - a ^= (a >> 47); - uint64_t b = (Uint128High64(x) ^ a) * kMul; - b ^= (b >> 47); - b *= kMul; - return b; -} - } // namespace hash_internal ABSL_NAMESPACE_END } // namespace absl |