diff options
| author | Erik Verbruggen <erik.verbruggen@theqtcompany.com> | 2015-12-03 12:50:44 +0100 |
|---|---|---|
| committer | Erik Verbruggen <erik.verbruggen@qt.io> | 2016-05-31 12:09:52 +0000 |
| commit | e70324f8dd1f191556599cf60100dd0ad0b16708 (patch) | |
| tree | 7b605613143718896810150614538feab022e5a2 /src/corelib/kernel | |
| parent | f7e29f07ffead8bd1cb6ff81bb791de2fb11fa5e (diff) | |
Remove _bit_scan_{forward,reverse}
Use qCountTrailingZeroBits and qCountLeadingZeroBits from qalgorithms.h
instead. Also extended these versions for MSVC. The _bit_scan_* versions
stem from a time before the glorious days of qalgorithms.h. A big
advantage is that these functions can be used on all platforms.
Change-Id: I5a1b886371520310a7fe16e617635ea335046beb
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Diffstat (limited to 'src/corelib/kernel')
| -rw-r--r-- | src/corelib/kernel/qmath.h | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/src/corelib/kernel/qmath.h b/src/corelib/kernel/qmath.h index c24fc3a0ce..773884047a 100644 --- a/src/corelib/kernel/qmath.h +++ b/src/corelib/kernel/qmath.h @@ -45,6 +45,7 @@ #endif #include <QtCore/qglobal.h> +#include <QtCore/qalgorithms.h> #ifndef _USE_MATH_DEFINES # define _USE_MATH_DEFINES @@ -241,20 +242,12 @@ Q_DECL_CONSTEXPR inline double qRadiansToDegrees(double radians) } -#if defined(Q_CC_GNU) -// clz instructions exist in at least MIPS, ARM, PowerPC and X86, so we can assume this builtin always maps to an efficient instruction. +#if defined(QT_HAS_BUILTIN_CLZ) inline quint32 qNextPowerOfTwo(quint32 v) { if (v == 0) return 1; - return 2U << (31 ^ __builtin_clz(v)); -} - -inline quint64 qNextPowerOfTwo(quint64 v) -{ - if (v == 0) - return 1; - return Q_UINT64_C(2) << (63 ^ __builtin_clzll(v)); + return 2U << (31 ^ QAlgorithmsPrivate::qt_builtin_clz(v)); } #else inline quint32 qNextPowerOfTwo(quint32 v) @@ -267,7 +260,16 @@ inline quint32 qNextPowerOfTwo(quint32 v) ++v; return v; } +#endif +#if defined(QT_HAS_BUILTIN_CLZLL) +inline quint64 qNextPowerOfTwo(quint64 v) +{ + if (v == 0) + return 1; + return Q_UINT64_C(2) << (63 ^ QAlgorithmsPrivate::qt_builtin_clzll(v)); +} +#else inline quint64 qNextPowerOfTwo(quint64 v) { v |= v >> 1; |