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| author | Allan Sandfeld Jensen <allan.jensen@qt.io> | 2020-08-08 12:52:36 +0200 |
|---|---|---|
| committer | Allan Sandfeld Jensen <allan.jensen@qt.io> | 2020-09-13 18:26:49 +0200 |
| commit | 6a37ca39ec7cfc2f4392784fd31936526d55e941 (patch) | |
| tree | 240d1a2034b87a0094b0fc96a07a46e3a3b0902b /src/corelib/kernel/qmath.h | |
| parent | 65afcef2173cabe297778d19dda3198595820cfa (diff) | |
Use universal C++20 bit operations when available
Avoids using compiler builtins, and can in future replace them.
Change-Id: I3f0afe7d28b6ba05bcd1c1132b44a8db7b182d8a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/corelib/kernel/qmath.h')
| -rw-r--r-- | src/corelib/kernel/qmath.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/corelib/kernel/qmath.h b/src/corelib/kernel/qmath.h index 5f36de303c..4c5a980f3a 100644 --- a/src/corelib/kernel/qmath.h +++ b/src/corelib/kernel/qmath.h @@ -47,6 +47,10 @@ #include <QtCore/qglobal.h> #include <QtCore/qalgorithms.h> +#if __has_include(<bit>) +#include <bit> +#endif + #ifndef _USE_MATH_DEFINES # define _USE_MATH_DEFINES # define undef_USE_MATH_DEFINES @@ -298,7 +302,9 @@ constexpr inline quint64 qConstexprNextPowerOfTwo(qint64 v) constexpr inline quint32 qNextPowerOfTwo(quint32 v) { -#if defined(QT_HAS_BUILTIN_CLZ) +#if defined(__cpp_lib_int_pow2) && __cpp_lib_int_pow2 >= 202002L + return std::bit_ceil(v + 1); +#elif defined(QT_HAS_BUILTIN_CLZ) if (v == 0) return 1; return 2U << (31 ^ QAlgorithmsPrivate::qt_builtin_clz(v)); @@ -309,7 +315,9 @@ constexpr inline quint32 qNextPowerOfTwo(quint32 v) constexpr inline quint64 qNextPowerOfTwo(quint64 v) { -#if defined(QT_HAS_BUILTIN_CLZLL) +#if defined(__cpp_lib_int_pow2) && __cpp_lib_int_pow2 >= 202002L + return std::bit_ceil(v + 1); +#elif defined(QT_HAS_BUILTIN_CLZLL) if (v == 0) return 1; return Q_UINT64_C(2) << (63 ^ QAlgorithmsPrivate::qt_builtin_clzll(v)); |