diff options
Diffstat (limited to 'src/corelib/kernel/qmath.h')
| -rw-r--r-- | src/corelib/kernel/qmath.h | 82 |
1 files changed, 63 insertions, 19 deletions
diff --git a/src/corelib/kernel/qmath.h b/src/corelib/kernel/qmath.h index 21e23b9eb0..997fd2ed0b 100644 --- a/src/corelib/kernel/qmath.h +++ b/src/corelib/kernel/qmath.h @@ -1,40 +1,32 @@ /**************************************************************************** ** -** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). +** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies). ** Contact: http://www.qt-project.org/legal ** ** This file is part of the QtCore module of the Qt Toolkit. ** -** $QT_BEGIN_LICENSE:LGPL$ +** $QT_BEGIN_LICENSE:LGPL21$ ** 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 Digia. For licensing terms and -** conditions see http://qt.digia.com/licensing. For further information +** a written agreement between you and Digia. For licensing terms and +** conditions see http://qt.digia.com/licensing. For further information ** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 2.1 requirements -** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** General Public License version 2.1 or version 3 as published by the Free +** Software Foundation and appearing in the file LICENSE.LGPLv21 and +** LICENSE.LGPLv3 included in the packaging of this file. Please review the +** following information to ensure the GNU Lesser General Public License +** requirements will be met: https://www.gnu.org/licenses/lgpl.html and +** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Digia gives you certain additional -** rights. These rights are described in the Digia Qt LGPL Exception +** rights. These rights are described in the Digia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 3.0 as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL included in the -** packaging of this file. Please review the following information to -** ensure the GNU General Public License version 3.0 requirements will be -** met: http://www.gnu.org/copyleft/gpl.html. -** -** ** $QT_END_LICENSE$ ** ****************************************************************************/ @@ -49,6 +41,7 @@ #include <math.h> #include <QtCore/qglobal.h> +#include <QtCore/qcompilerdetection.h> QT_BEGIN_NAMESPACE @@ -286,6 +279,57 @@ Q_DECL_CONSTEXPR inline double qRadiansToDegrees(double radians) return radians * (180 / M_PI); } + +#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. +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)); +} +#else +inline quint32 qNextPowerOfTwo(quint32 v) +{ + v |= v >> 1; + v |= v >> 2; + v |= v >> 4; + v |= v >> 8; + v |= v >> 16; + ++v; + return v; +} + +inline quint64 qNextPowerOfTwo(quint64 v) +{ + v |= v >> 1; + v |= v >> 2; + v |= v >> 4; + v |= v >> 8; + v |= v >> 16; + v |= v >> 32; + ++v; + return v; +} +#endif + +inline quint32 qNextPowerOfTwo(qint32 v) +{ + return qNextPowerOfTwo(quint32(v)); +} + +inline quint64 qNextPowerOfTwo(qint64 v) +{ + return qNextPowerOfTwo(quint64(v)); +} + QT_END_NAMESPACE #endif // QMATH_H |