diff options
Diffstat (limited to 'src/corelib/tools/qhashfunctions.h')
| -rw-r--r-- | src/corelib/tools/qhashfunctions.h | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/src/corelib/tools/qhashfunctions.h b/src/corelib/tools/qhashfunctions.h index 43a7b4b599..b7182ac6d4 100644 --- a/src/corelib/tools/qhashfunctions.h +++ b/src/corelib/tools/qhashfunctions.h @@ -104,7 +104,22 @@ Q_DECL_CONST_FUNCTION constexpr inline size_t qHash(quint64 key, size_t seed = 0 return QHashPrivate::hash(size_t(key), seed); } Q_DECL_CONST_FUNCTION constexpr inline size_t qHash(qint64 key, size_t seed = 0) noexcept -{ return qHash(quint64(key), seed); } +{ + if constexpr (sizeof(qint64) > sizeof(size_t)) { + // Avoid QTBUG-116080: we XOR the top half with its own sign bit: + // - if the qint64 is in range of qint32, then signmask ^ high == 0 + // (for Qt 7 only) + // - if the qint64 is in range of quint32, then signmask == 0 and we + // do the same as the quint64 overload above + quint32 high = quint32(quint64(key) >> 32); + quint32 low = quint32(quint64(key)); + quint32 signmask = qint32(high) >> 31; // all zeroes or all ones + signmask = QT_VERSION_MAJOR > 6 ? signmask : 0; + low ^= signmask ^ high; + return qHash(low, seed); + } + return qHash(quint64(key), seed); +} #if QT_SUPPORTS_INT128 constexpr size_t qHash(quint128 key, size_t seed = 0) noexcept { @@ -112,10 +127,8 @@ constexpr size_t qHash(quint128 key, size_t seed = 0) noexcept } constexpr size_t qHash(qint128 key, size_t seed = 0) noexcept { - // Avoid QTBUG-116080: we XOR the top half with its own sign bit: - // - if the qint128 is in range of qint64, then signmask ^ high == 0 - // - if the qint128 is in range of quint64, then signmask == 0 and we - // do the same as the quint128 overload above + // Avoid QTBUG-116080: same as above, but with double the sizes and without + // the need for compatibility quint64 high = quint64(quint128(key) >> 64); quint64 low = quint64(quint128(key)); quint64 signmask = qint64(high) >> 63; // all zeroes or all ones |