diff options
Diffstat (limited to 'src/corelib/tools/qhashfunctions.h')
| -rw-r--r-- | src/corelib/tools/qhashfunctions.h | 58 |
1 files changed, 44 insertions, 14 deletions
diff --git a/src/corelib/tools/qhashfunctions.h b/src/corelib/tools/qhashfunctions.h index 2ff3464912..2e62e93ac4 100644 --- a/src/corelib/tools/qhashfunctions.h +++ b/src/corelib/tools/qhashfunctions.h @@ -68,25 +68,55 @@ class QLatin1String; Q_CORE_EXPORT int qGlobalQHashSeed(); Q_CORE_EXPORT void qSetGlobalQHashSeed(int newSeed); -Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHashBits(const void *p, size_t size, uint seed = 0) noexcept; +namespace QHashPrivate { -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(char key, uint seed = 0) noexcept { return uint(key) ^ seed; } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uchar key, uint seed = 0) noexcept { return uint(key) ^ seed; } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(signed char key, uint seed = 0) noexcept { return uint(key) ^ seed; } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ushort key, uint seed = 0) noexcept { return uint(key) ^ seed; } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(short key, uint seed = 0) noexcept { return uint(key) ^ seed; } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uint key, uint seed = 0) noexcept { return key ^ seed; } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(int key, uint seed = 0) noexcept { return uint(key) ^ seed; } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ulong key, uint seed = 0) noexcept +Q_DECL_CONST_FUNCTION constexpr uint hash(size_t key, uint seed) noexcept { - return (sizeof(ulong) > sizeof(uint)) - ? (uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U)) ^ seed) - : (uint(key & (~0U)) ^ seed); + key ^= seed; + if constexpr (sizeof(size_t) == 4) { + key ^= key >> 16; + key *= UINT32_C(0x45d9f3b); + key ^= key >> 16; + key *= UINT32_C(0x45d9f3b); + key ^= key >> 16; + return key; + } else { + key ^= key >> 32; + key *= UINT64_C(0xd6e8feb86659fd93); + key ^= key >> 32; + key *= UINT64_C(0xd6e8feb86659fd93); + key ^= key >> 32; + return uint(key); + } +} + } -Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(long key, uint seed = 0) noexcept { return qHash(ulong(key), seed); } + +Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHashBits(const void *p, size_t size, uint seed = 0) noexcept; + +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(char key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uchar key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(signed char key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ushort key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(short key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uint key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(int key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ulong key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } +Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(long key, uint seed = 0) noexcept +{ return QHashPrivate::hash(size_t(key), seed); } Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(quint64 key, uint seed = 0) noexcept { - return uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U)) ^ seed; + if (sizeof(quint64) > sizeof(size_t)) + key ^= (key >> 32); + return QHashPrivate::hash(size_t(key), seed); } Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(qint64 key, uint seed = 0) noexcept { return qHash(quint64(key), seed); } Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(float key, uint seed = 0) noexcept; |