diff options
Diffstat (limited to 'src/corelib/tools/qalgorithms.h')
| -rw-r--r-- | src/corelib/tools/qalgorithms.h | 139 |
1 files changed, 115 insertions, 24 deletions
diff --git a/src/corelib/tools/qalgorithms.h b/src/corelib/tools/qalgorithms.h index 854276d150..568b9cc95c 100644 --- a/src/corelib/tools/qalgorithms.h +++ b/src/corelib/tools/qalgorithms.h @@ -516,6 +516,105 @@ QT_DEPRECATED_X("Use std::binary_search") Q_OUTOFLINE_TEMPLATE RandomAccessItera #endif // QT_DEPRECATED_SINCE(5, 2) +// Clang had a bug where __builtin_ctz/clz is not marked as constexpr. +#if defined Q_CC_CLANG && defined __apple_build_version__ && __clang_major__ < 7 +# undef QT_HAS_CONSTEXPR_BUILTIN_CTZ_CLZ +#else +# define QT_HAS_CONSTEXPR_BUILTIN_CTZ_CLZ +#endif + +#if defined QT_HAS_CONSTEXPR_BUILTIN_CTZ_CLZ +#if defined(Q_CC_GNU) +# define QT_HAS_BUILTIN_CTZS +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) Q_DECL_NOTHROW +{ +# if QT_HAS_BUILTIN(__builtin_ctzs) || defined(__BMI__) + return __builtin_ctzs(v); +# else + return __builtin_ctz(v); +# endif +} +#define QT_HAS_BUILTIN_CLZS +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) Q_DECL_NOTHROW +{ +# if QT_HAS_BUILTIN(__builtin_clzs) || defined(__BMI__) + return __builtin_clzs(v); +# else + return __builtin_clz(v) - 16U; +# endif +} +#define QT_HAS_BUILTIN_CTZ +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctz(quint32 v) Q_DECL_NOTHROW +{ + return __builtin_ctz(v); +} +#define QT_HAS_BUILTIN_CLZ +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clz(quint32 v) Q_DECL_NOTHROW +{ + return __builtin_clz(v); +} +#define QT_HAS_BUILTIN_CTZLL +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzll(quint64 v) Q_DECL_NOTHROW +{ + return __builtin_ctzll(v); +} +#define QT_HAS_BUILTIN_CLZLL +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzll(quint64 v) Q_DECL_NOTHROW +{ + return __builtin_clzll(v); +} +#elif defined(Q_CC_MSVC) && !defined(Q_OS_WINCE) +#define QT_HAS_BUILTIN_CTZ +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE unsigned long qt_builtin_ctz(quint32 val) +{ + unsigned long result; + _BitScanForward(&result, val); + return result; +} +#define QT_HAS_BUILTIN_CLZ +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE unsigned long qt_builtin_clz(quint32 val) +{ + unsigned long result; + _BitScanReverse(&result, val); + // Now Invert the result: clz will count *down* from the msb to the lsb, so the msb index is 31 + // and the lsb index is 0. The result for the index when counting up: msb index is 0 (because it + // starts there), and the lsb index is 31. + result ^= sizeof(quint32) * 8 - 1; + return result; +} +#if Q_PROCESSOR_WORDSIZE == 8 +// These are only defined for 64bit builds. +#define QT_HAS_BUILTIN_CTZLL +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE unsigned long qt_builtin_ctzll(quint64 val) +{ + unsigned long result; + _BitScanForward64(&result, val); + return result; +} +// MSVC calls it _BitScanReverse and returns the carry flag, which we don't need +#define QT_HAS_BUILTIN_CLZLL +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE unsigned long qt_builtin_clzll(quint64 val) +{ + unsigned long result; + _BitScanReverse64(&result, val); + // see qt_builtin_clz + result ^= sizeof(quint64) * 8 - 1; + return result; +} +#endif +# define QT_HAS_BUILTIN_CTZS +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) Q_DECL_NOTHROW +{ + return qt_builtin_ctz(v); +} +#define QT_HAS_BUILTIN_CLZS +Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) Q_DECL_NOTHROW +{ + return qt_builtin_clz(v) - 16U; +} +#endif +#endif // QT_HAS_CONSTEXPR_BUILTIN_CTZ_CLZ + } //namespace QAlgorithmsPrivate @@ -586,8 +685,8 @@ Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qPopulationCount(long unsigne Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint32 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) - return v ? __builtin_ctz(v) : 32U; +#if defined(QT_HAS_BUILTIN_CTZ) + return v ? QAlgorithmsPrivate::qt_builtin_ctz(v) : 32U; #else // see http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightParallel unsigned int c = 32; // c will be the number of zero bits on the right @@ -604,8 +703,8 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint32 v) Q_DECL_NO Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint8 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) - return v ? __builtin_ctz(v) : 8U; +#if defined(QT_HAS_BUILTIN_CTZ) + return v ? QAlgorithmsPrivate::qt_builtin_ctz(v) : 8U; #else unsigned int c = 8; // c will be the number of zero bits on the right v &= -signed(v); @@ -619,12 +718,8 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint8 v) Q_DECL_NOT Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint16 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) -# if QT_HAS_BUILTIN(__builtin_ctzs) || defined(__BMI__) - return v ? __builtin_ctzs(v) : 16U; -# else - return v ? __builtin_ctz(v) : 16U; -# endif +#if defined(QT_HAS_BUILTIN_CTZS) + return v ? QAlgorithmsPrivate::qt_builtin_ctzs(v) : 16U; #else unsigned int c = 16; // c will be the number of zero bits on the right v &= -signed(v); @@ -639,8 +734,8 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint16 v) Q_DECL_NO Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint64 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) - return v ? __builtin_ctzll(v) : 64; +#if defined(QT_HAS_BUILTIN_CTZLL) + return v ? QAlgorithmsPrivate::qt_builtin_ctzll(v) : 64; #else quint32 x = static_cast<quint32>(v); return x ? qCountTrailingZeroBits(x) @@ -655,8 +750,8 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(unsigned long v) Q_D Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint32 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) - return v ? __builtin_clz(v) : 32U; +#if defined(QT_HAS_BUILTIN_CLZ) + return v ? QAlgorithmsPrivate::qt_builtin_clz(v) : 32U; #else // Hacker's Delight, 2nd ed. Fig 5-16, p. 102 v = v | (v >> 1); @@ -670,8 +765,8 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint32 v) Q_DECL_NOT Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) - return v ? __builtin_clz(v)-24U : 8U; +#if defined(QT_HAS_BUILTIN_CLZ) + return v ? QAlgorithmsPrivate::qt_builtin_clz(v)-24U : 8U; #else v = v | (v >> 1); v = v | (v >> 2); @@ -682,12 +777,8 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) Q_DECL_NOTH Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) -# if QT_HAS_BUILTIN(__builtin_clzs) || defined(__BMI__) - return v ? __builtin_clzs(v) : 16U; -# else - return v ? __builtin_clz(v)-16U : 16U; -# endif +#if defined(QT_HAS_BUILTIN_CLZS) + return v ? QAlgorithmsPrivate::qt_builtin_clzs(v) : 16U; #else v = v | (v >> 1); v = v | (v >> 2); @@ -699,8 +790,8 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) Q_DECL_NOT Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint64 v) Q_DECL_NOTHROW { -#if defined(Q_CC_GNU) - return v ? __builtin_clzll(v) : 64U; +#if defined(QT_HAS_BUILTIN_CLZLL) + return v ? QAlgorithmsPrivate::qt_builtin_clzll(v) : 64U; #else v = v | (v >> 1); v = v | (v >> 2); |