diff options
Diffstat (limited to 'src/corelib/global/qendian.cpp')
| -rw-r--r-- | src/corelib/global/qendian.cpp | 919 |
1 files changed, 919 insertions, 0 deletions
diff --git a/src/corelib/global/qendian.cpp b/src/corelib/global/qendian.cpp new file mode 100644 index 0000000000..7fd6e13d3b --- /dev/null +++ b/src/corelib/global/qendian.cpp @@ -0,0 +1,919 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Copyright (C) 2018 Intel Corporation. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qendian.h" + +#include "qalgorithms.h" +#include <private/qsimd_p.h> + +QT_BEGIN_NAMESPACE + +/*! + \headerfile <QtEndian> + \title Endian Conversion Functions + \ingroup funclists + \brief The <QtEndian> header provides functions to convert between + little and big endian representations of numbers. +*/ + +/*! + \fn template <typename T> T qFromUnaligned(const void *ptr) + \internal + \since 5.5 + + Loads a \c{T} from address \a ptr, which may be misaligned. + + Use of this function avoids the undefined behavior that the C++ standard + otherwise attributes to unaligned loads. +*/ + +/*! + \fn template <typename T> void qToUnaligned(const T t, void *ptr) + \internal + \since 4.5 + + Stores \a t to address \a ptr, which may be misaligned. + + Use of this function avoids the undefined behavior that the C++ standard + otherwise attributes to unaligned stores. +*/ + + +/*! + \fn template <typename T> T qFromBigEndian(const void *src) + \since 4.3 + \relates <QtEndian> + + Reads a big-endian number from memory location \a src and returns the number in the + host byte order representation. + On CPU architectures where the host byte order is little-endian (such as x86) this + will swap the byte order; otherwise it will just read from \a src. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + \note Since Qt 5.7, the type of the \a src parameter is a void pointer. + + There are no data alignment constraints for \a src. + + \sa qFromLittleEndian() + \sa qToBigEndian() + \sa qToLittleEndian() +*/ +/*! + \fn template <typename T> T qFromBigEndian(T src) + \since 4.3 + \relates <QtEndian> + \overload + + Converts \a src from big-endian byte order and returns the number in host byte order + representation of that number. + On CPU architectures where the host byte order is little-endian (such as x86) this + will return \a src with the byte order swapped; otherwise it will return \a src + unmodified. +*/ +/*! + \fn template <typename T> T qFromBigEndian(const void *src, qsizetype count, void *dest) + \since 5.12 + \relates <QtEndian> + + Reads \a count big-endian numbers from memory location \a src and stores + them in the host byte order representation at \a dest. On CPU architectures + where the host byte order is little-endian (such as x86) this will swap the + byte order; otherwise it will just perform a \c memcpy from \a src to \a + dest. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + There are no data alignment constraints for \a src. However, \a dest is + expected to be naturally aligned for type \c{T}. + + If \a src and \a dest can be the same pointer, this function will perform + an in-place swap (if necessary). If they are not the same, the memory + regions must not overlap. + + \sa qFromLittleEndian() + \sa qToBigEndian() + \sa qToLittleEndian() +*/ +/*! + \fn template <typename T> T qFromLittleEndian(const void *src) + \since 4.3 + \relates <QtEndian> + + Reads a little-endian number from memory location \a src and returns the number in + the host byte order representation. + On CPU architectures where the host byte order is big-endian (such as PowerPC) this + will swap the byte order; otherwise it will just read from \a src. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + \note Since Qt 5.7, the type of the \a src parameter is a void pointer. + + There are no data alignment constraints for \a src. + + \sa qFromBigEndian() + \sa qToBigEndian() + \sa qToLittleEndian() +*/ +/*! + \fn template <typename T> T qFromLittleEndian(T src) + \since 4.3 + \relates <QtEndian> + \overload + + Converts \a src from little-endian byte order and returns the number in host byte + order representation of that number. + On CPU architectures where the host byte order is big-endian (such as PowerPC) this + will return \a src with the byte order swapped; otherwise it will return \a src + unmodified. +*/ +/*! + \fn template <typename T> T qFromLittleEndian(const void *src, qsizetype count, void *dest) + \since 5.12 + \relates <QtEndian> + + Reads \a count little-endian numbers from memory location \a src and stores + them in the host byte order representation at \a dest. On CPU architectures + where the host byte order is big-endian (such as PowerPC) this will swap the + byte order; otherwise it will just perform a \c memcpy from \a src to \a + dest. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + There are no data alignment constraints for \a src. However, \a dest is + expected to be naturally aligned for type \c{T}. + + If \a src and \a dest can be the same pointer, this function will perform + an in-place swap (if necessary). If they are not the same, the memory + regions must not overlap. + + \sa qFromLittleEndian() + \sa qToBigEndian() + \sa qToLittleEndian() +*/ +/*! + \fn template <typename T> void qToBigEndian(T src, void *dest) + \since 4.3 + \relates <QtEndian> + + Writes the number \a src with template type \c{T} to the memory location at \a dest + in big-endian byte order. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + There are no data alignment constraints for \a dest. + + \note Since Qt 5.7, the type of the \a dest parameter is a void pointer. + + \sa qFromBigEndian() + \sa qFromLittleEndian() + \sa qToLittleEndian() +*/ +/*! + \fn template <typename T> T qToBigEndian(T src) + \since 4.3 + \relates <QtEndian> + \overload + + Converts \a src from host byte order and returns the number in big-endian byte order + representation of that number. + On CPU architectures where the host byte order is little-endian (such as x86) this + will return \a src with the byte order swapped; otherwise it will return \a src + unmodified. +*/ +/*! + \fn template <typename T> T qToBigEndian(const void *src, qsizetype count, void *dest) + \since 5.12 + \relates <QtEndian> + + Reads \a count numbers from memory location \a src in the host byte order + and stores them in big-endian representation at \a dest. On CPU + architectures where the host byte order is little-endian (such as x86) this + will swap the byte order; otherwise it will just perform a \c memcpy from + \a src to \a dest. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + There are no data alignment constraints for \a dest. However, \a src is + expected to be naturally aligned for type \c{T}. + + If \a src and \a dest can be the same pointer, this function will perform + an in-place swap (if necessary). If they are not the same, the memory + regions must not overlap. + + \sa qFromLittleEndian() + \sa qToBigEndian() + \sa qToLittleEndian() +*/ +/*! + \fn template <typename T> void qToLittleEndian(T src, void *dest) + \since 4.3 + \relates <QtEndian> + + Writes the number \a src with template type \c{T} to the memory location at \a dest + in little-endian byte order. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + There are no data alignment constraints for \a dest. + + \note Since Qt 5.7, the type of the \a dest parameter is a void pointer. + + \sa qFromBigEndian() + \sa qFromLittleEndian() + \sa qToBigEndian() +*/ +/*! + \fn template <typename T> T qToLittleEndian(T src) + \since 4.3 + \relates <QtEndian> + \overload + + Converts \a src from host byte order and returns the number in little-endian byte + order representation of that number. + On CPU architectures where the host byte order is big-endian (such as PowerPC) this + will return \a src with the byte order swapped; otherwise it will return \a src + unmodified. +*/ +/*! + \fn template <typename T> T qToLittleEndian(const void *src, qsizetype count, void *dest) + \since 5.12 + \relates <QtEndian> + + Reads \a count numbers from memory location \a src in the host byte order + and stores them in little-endian representation at \a dest. On CPU + architectures where the host byte order is big-endian (such as PowerPC) + this will swap the byte order; otherwise it will just perform a \c memcpy + from \a src to \a dest. + + \note Template type \c{T} can either be a quint16, qint16, quint32, qint32, + quint64, or qint64. Other types of integers, e.g., qlong, are not + applicable. + + There are no data alignment constraints for \a dest. However, \a src is + expected to be naturally aligned for type \c{T}. + + If \a src and \a dest can be the same pointer, this function will perform + an in-place swap (if necessary). If they are not the same, the memory + regions must not overlap. + + \sa qFromLittleEndian() + \sa qToBigEndian() + \sa qToLittleEndian() +*/ + +/*! + \class QLEInteger + \inmodule QtCore + \brief The QLEInteger class provides platform-independent little-endian integers. + \since 5.10 + + The template parameter \c T must be a C++ integer type: + \list + \li 8-bit: char, signed char, unsigned char, qint8, quint8 + \li 16-bit: short, unsigned short, qint16, quint16, char16_t + \li 32-bit: int, unsigned int, qint32, quint32, char32_t + \li 64-bit: long long, unsigned long long, qint64, quint64 + \li platform-specific size: long, unsigned long + \li pointer size: qintptr, quintptr, qptrdiff + \endlist + + \note Using this class may be slower than using native integers, so only use it when + an exact endianness is needed. +*/ + +/*! \fn template <typename T> QLEInteger<T>::QLEInteger(T value) + + Constructs a QLEInteger with the given \a value. +*/ + +/*! \fn template <typename T> QLEInteger &QLEInteger<T>::operator=(T i) + + Assigns \a i to this QLEInteger and returns a reference to + this QLEInteger. +*/ + +/*! + \fn template <typename T> QLEInteger<T>::operator T() const + + Returns the value of this QLEInteger as a native integer. +*/ + +/*! + \fn template <typename T> bool QLEInteger<T>::operator==(QLEInteger other) const + + Returns \c true if the value of this QLEInteger is equal to the value of \a other. +*/ + +/*! + \fn template <typename T> bool QLEInteger<T>::operator!=(QLEInteger other) const + + Returns \c true if the value of this QLEInteger is not equal to the value of \a other. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator+=(T i) + + Adds \a i to this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator-=(T i) + + Subtracts \a i from this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator*=(T i) + + Multiplies \a i with this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator/=(T i) + + Divides this QLEInteger with \a i and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator%=(T i) + + Sets this QLEInteger to the remainder of a division by \a i and + returns a reference to this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator>>=(T i) + + Performs a left-shift by \a i on this QLEInteger and returns a + reference to this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator<<=(T i) + + Performs a right-shift by \a i on this QLEInteger and returns a + reference to this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator|=(T i) + + Performs a bitwise OR with \a i onto this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator&=(T i) + + Performs a bitwise AND with \a i onto this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator^=(T i) + + Performs a bitwise XOR with \a i onto this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator++() + + Performs a prefix ++ (increment) on this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger QLEInteger<T>::operator++(int) + + Performs a postfix ++ (increment) on this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger &QLEInteger<T>::operator--() + + Performs a prefix -- (decrement) on this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger QLEInteger<T>::operator--(int) + + Performs a postfix -- (decrement) on this QLEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QLEInteger QLEInteger<T>::max() + + Returns the maximum (finite) value representable by the numeric type T. +*/ + +/*! + \fn template <typename T> QLEInteger QLEInteger<T>::min() + + Returns the minimum (finite) value representable by the numeric type T. +*/ + +/*! + \class QBEInteger + \inmodule QtCore + \brief The QBEInteger class provides platform-independent big-endian integers. + \since 5.10 + + The template parameter \c T must be a C++ integer type: + \list + \li 8-bit: char, signed char, unsigned char, qint8, quint8 + \li 16-bit: short, unsigned short, qint16, quint16, char16_t (C++11) + \li 32-bit: int, unsigned int, qint32, quint32, char32_t (C++11) + \li 64-bit: long long, unsigned long long, qint64, quint64 + \li platform-specific size: long, unsigned long + \li pointer size: qintptr, quintptr, qptrdiff + \endlist + + \note Using this class may be slower than using native integers, so only use it when + an exact endianness is needed. +*/ + +/*! \fn template <typename T> QBEInteger<T>::QBEInteger(T value) + + Constructs a QBEInteger with the given \a value. +*/ + +/*! \fn template <typename T> QBEInteger &QBEInteger<T>::operator=(T i) + + Assigns \a i to this QBEInteger and returns a reference to + this QBEInteger. +*/ + +/*! + \fn template <typename T> QBEInteger<T>::operator T() const + + Returns the value of this QBEInteger as a native integer. +*/ + +/*! + \fn template <typename T> bool QBEInteger<T>::operator==(QBEInteger other) const + + Returns \c true if the value of this QBEInteger is equal to the value of \a other. +*/ + +/*! + \fn template <typename T> bool QBEInteger<T>::operator!=(QBEInteger other) const + + Returns \c true if the value of this QBEInteger is not equal to the value of \a other. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator+=(T i) + + Adds \a i to this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator-=(T i) + + Subtracts \a i from this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator*=(T i) + + Multiplies \a i with this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator/=(T i) + + Divides this QBEInteger with \a i and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator%=(T i) + + Sets this QBEInteger to the remainder of a division by \a i and + returns a reference to this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator>>=(T i) + + Performs a left-shift by \a i on this QBEInteger and returns a + reference to this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator<<=(T i) + + Performs a right-shift by \a i on this QBEInteger and returns a + reference to this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator|=(T i) + + Performs a bitwise OR with \a i onto this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator&=(T i) + + Performs a bitwise AND with \a i onto this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator^=(T i) + + Performs a bitwise XOR with \a i onto this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator++() + + Performs a prefix ++ (increment) on this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger QBEInteger<T>::operator++(int) + + Performs a postfix ++ (increment) on this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger &QBEInteger<T>::operator--() + + Performs a prefix -- (decrement) on this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger QBEInteger<T>::operator--(int) + + Performs a postfix -- (decrement) on this QBEInteger and returns a reference to + this object. +*/ + +/*! + \fn template <typename T> QBEInteger QBEInteger<T>::max() + + Returns the maximum (finite) value representable by the numeric type T. +*/ + +/*! + \fn template <typename T> QBEInteger QBEInteger<T>::min() + + Returns the minimum (finite) value representable by the numeric type T. +*/ + +/*! + \typedef quint16_le + \relates <QtEndian> + \since 5.10 + + Typedef for QLEInteger<quint16>. This type is guaranteed to be stored in memory as + a 16-bit little-endian unsigned integer on all platforms supported by Qt. + + \sa quint16 +*/ + +/*! + \typedef quint32_le + \relates <QtEndian> + \since 5.10 + + Typedef for QLEInteger<quint32>. This type is guaranteed to be stored in memory as + a 32-bit little-endian unsigned integer on all platforms supported by Qt. + + \sa quint32 +*/ + +/*! + \typedef quint64_le + \relates <QtEndian> + \since 5.10 + + Typedef for QLEInteger<quint64>. This type is guaranteed to be stored in memory as + a 64-bit little-endian unsigned integer on all platforms supported by Qt. + + \sa quint64 +*/ + +/*! + \typedef quint16_be + \relates <QtEndian> + \since 5.10 + + Typedef for QBEInteger<quint16>. This type is guaranteed to be stored in memory as + a 16-bit big-endian unsigned integer on all platforms supported by Qt. + + \sa quint16 +*/ + +/*! + \typedef quint32_be + \relates <QtEndian> + \since 5.10 + + Typedef for QBEInteger<quint32>. This type is guaranteed to be stored in memory as + a 32-bit big-endian unsigned integer on all platforms supported by Qt. + + \sa quint32 +*/ + +/*! + \typedef quint64_be + \relates <QtEndian> + \since 5.10 + + Typedef for QBEInteger<quint64>. This type is guaranteed to be stored in memory as + a 64-bit big-endian unsigned integer on all platforms supported by Qt. + + \sa quint64 +*/ + +/*! + \typedef qint16_le + \relates <QtEndian> + \since 5.10 + + Typedef for QLEInteger<qint16>. This type is guaranteed to be stored in memory as + a 16-bit little-endian signed integer on all platforms supported by Qt. + + \sa qint16 +*/ + +/*! + \typedef qint32_le + \relates <QtEndian> + \since 5.10 + + Typedef for QLEInteger<qint32>. This type is guaranteed to be stored in memory as + a 32-bit little-endian signed integer on all platforms supported by Qt. + + \sa qint32 +*/ + +/*! + \typedef qint64_le + \relates <QtEndian> + \since 5.10 + + Typedef for QLEInteger<qint64>. This type is guaranteed to be stored in memory as + a 64-bit little-endian signed integer on all platforms supported by Qt. + + \sa qint64 +*/ + +/*! + \typedef qint16_be + \relates <QtEndian> + \since 5.10 + + Typedef for QBEInteger<qint16>. This type is guaranteed to be stored in memory as + a 16-bit big-endian signed integer on all platforms supported by Qt. + + \sa qint16 +*/ + +/*! + \typedef qint32_be + \relates <QtEndian> + \since 5.10 + + Typedef for QBEInteger<qint32>. This type is guaranteed to be stored in memory as + a 32-bit big-endian signed integer on all platforms supported by Qt. + + \sa qint32 +*/ + +/*! + \typedef qint64_be + \relates <QtEndian> + \since 5.10 + + Typedef for QBEInteger<qint64>. This type is guaranteed to be stored in memory as + a 64-bit big-endian signed integer on all platforms supported by Qt. + + \sa qint64 +*/ + +#if defined(__SSSE3__) +using ShuffleMask = uchar[16]; +Q_DECL_ALIGN(16) static const ShuffleMask shuffleMasks[3] = { + // 16-bit + {1, 0, 3, 2, 5, 4, 7, 6, 9, 8, 11, 10, 13, 12, 15, 14}, + // 32-bit + {3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12}, + // 64-bit + {7, 6, 5, 4, 3, 2, 1, 0, 15, 14, 13, 12, 11, 10, 9, 8} +}; + +static size_t sseSwapLoop(const uchar *src, size_t bytes, uchar *dst, + const __m128i *shuffleMaskPtr) noexcept +{ + size_t i = 0; + const __m128i shuffleMask = _mm_load_si128(shuffleMaskPtr); + +# ifdef __AVX2__ + const __m256i shuffleMask256 = _mm256_inserti128_si256(_mm256_castsi128_si256(shuffleMask), shuffleMask, 1); + for ( ; i + sizeof(__m256i) <= bytes; i += sizeof(__m256i)) { + __m256i data = _mm256_loadu_si256(reinterpret_cast<const __m256i *>(src + i)); + data = _mm256_shuffle_epi8(data, shuffleMask256); + _mm256_storeu_si256(reinterpret_cast<__m256i *>(dst + i), data); + } +# else + for ( ; i + 2 * sizeof(__m128i) <= bytes; i += 2 * sizeof(__m128i)) { + __m128i data1 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(src + i)); + __m128i data2 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(src + i) + 1); + data1 = _mm_shuffle_epi8(data1, shuffleMask); + data2 = _mm_shuffle_epi8(data2, shuffleMask); + _mm_storeu_si128(reinterpret_cast<__m128i *>(dst + i), data1); + _mm_storeu_si128(reinterpret_cast<__m128i *>(dst + i) + 1, data2); + } +# endif + + if (i + sizeof(__m128i) <= bytes) { + __m128i data = _mm_loadu_si128(reinterpret_cast<const __m128i *>(src + i)); + data = _mm_shuffle_epi8(data, shuffleMask); + _mm_storeu_si128(reinterpret_cast<__m128i *>(dst + i), data); + i += sizeof(__m128i); + } + + return i; +} + +template <typename T> static Q_ALWAYS_INLINE +size_t simdSwapLoop(const uchar *src, size_t bytes, uchar *dst) noexcept +{ + auto shuffleMaskPtr = reinterpret_cast<const __m128i *>(shuffleMasks[0]); + shuffleMaskPtr += qCountTrailingZeroBits(sizeof(T)) - 1; + size_t i = sseSwapLoop(src, bytes, dst, shuffleMaskPtr); + + // epilogue + for (size_t _i = 0 ; i < bytes && _i < sizeof(__m128i); i += sizeof(T), _i += sizeof(T)) + qbswap(qFromUnaligned<T>(src + i), dst + i); + + // return the total, so the bswapLoop below does nothing + return bytes; +} +#elif defined(__SSE2__) +template <typename T> static +size_t simdSwapLoop(const uchar *, size_t, uchar *) noexcept +{ + // no generic version: we can't do 32- and 64-bit swaps easily, + // so we won't try + return 0; +} + +template <> size_t simdSwapLoop<quint16>(const uchar *src, size_t bytes, uchar *dst) noexcept +{ + auto swapEndian = [](__m128i &data) { + __m128i lows = _mm_srli_epi16(data, 8); + __m128i highs = _mm_slli_epi16(data, 8); + data = _mm_xor_si128(lows, highs); + }; + + size_t i = 0; + for ( ; i + 2 * sizeof(__m128i) <= bytes; i += 2 * sizeof(__m128i)) { + __m128i data1 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(src + i)); + __m128i data2 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(src + i) + 1); + swapEndian(data1); + swapEndian(data2); + _mm_storeu_si128(reinterpret_cast<__m128i *>(dst + i), data1); + _mm_storeu_si128(reinterpret_cast<__m128i *>(dst + i) + 1, data2); + } + + if (i + sizeof(__m128i) <= bytes) { + __m128i data = _mm_loadu_si128(reinterpret_cast<const __m128i *>(src + i)); + swapEndian(data); + _mm_storeu_si128(reinterpret_cast<__m128i *>(dst + i), data); + i += sizeof(__m128i); + } + + // epilogue + for (size_t _i = 0 ; i < bytes && _i < sizeof(__m128i); i += sizeof(quint16), _i += sizeof(quint16)) + qbswap(qFromUnaligned<quint16>(src + i), dst + i); + + // return the total, so the bswapLoop below does nothing + return bytes; +} +#else +template <typename T> static Q_ALWAYS_INLINE +size_t simdSwapLoop(const uchar *, size_t, uchar *) noexcept +{ + return 0; +} +#endif + +template <typename T> static Q_ALWAYS_INLINE +void *bswapLoop(const uchar *src, size_t n, uchar *dst) noexcept +{ + // Buffers cannot partially overlap: either they're identical or totally + // disjoint (note: they can be adjacent). + if (src != dst) { + quintptr s = quintptr(src); + quintptr d = quintptr(dst); + if (s < d) + Q_ASSERT(s + n <= d); + else + Q_ASSERT(d + n <= s); + } + + size_t i = simdSwapLoop<T>(src, n, dst); + + for ( ; i < n; i += sizeof(T)) + qbswap(qFromUnaligned<T>(src + i), dst + i); + return dst + i; +} + +template <> void *qbswap<2>(const void *source, qsizetype n, void *dest) noexcept +{ + const uchar *src = reinterpret_cast<const uchar *>(source); + uchar *dst = reinterpret_cast<uchar *>(dest); + + return bswapLoop<quint16>(src, n << 1, dst); +} + +template <> void *qbswap<4>(const void *source, qsizetype n, void *dest) noexcept +{ + const uchar *src = reinterpret_cast<const uchar *>(source); + uchar *dst = reinterpret_cast<uchar *>(dest); + + return bswapLoop<quint32>(src, n << 2, dst); +} + +template <> void *qbswap<8>(const void *source, qsizetype n, void *dest) noexcept +{ + const uchar *src = reinterpret_cast<const uchar *>(source); + uchar *dst = reinterpret_cast<uchar *>(dest); + + return bswapLoop<quint64>(src, n << 3, dst); +} + +QT_END_NAMESPACE |