whytofly
/
qt6-bb10
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Unduplicate the implementations of next power of two 

Qtbase contains four identical implementations of next power of two,
these should be shared and the implementation made available to other
qt modules, as it is also used many places outside of qtbase.

[ChangeLog][QtCore][QtMath] Introduced qNextPowerOfTwo methods.

Change-Id: Id23fbe5ad6bae647b30d5a4212c0330e48a50278
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
bb10
Allan Sandfeld Jensen 2014-03-25 16:16:57 +01:00
parent ef077750ce
commit b6ba4ac00d
7 changed files with 214 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
src/corelib/kernel/qmath.h
View File

@ -49,6 +49,7 @@
#include <math.h>
#include <QtCore/qglobal.h>
#include <QtCore/qcompilerdetection.h>
QT_BEGIN_NAMESPACE
@ -286,6 +287,57 @@ 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

33
src/corelib/kernel/qmath.qdoc
View File

@ -215,4 +215,37 @@
\snippet code/src_corelib_kernel_qmath.cpp 3
\sa qDegreesToRadians()
/*!
\fn quint32 qNextPowerOfTwo(quint32 value)
\relates <QtMath>
\since 5.4
This function returns the nearest power of two greater than \a value. For 0 it returns 1, and for values larger than or equal to 2^31 it returns 0.
*/
/*!
\fn quint32 qNextPowerOfTwo(qint32 value)
\relates <QtMath>
\since 5.4
\overload
This function returns the nearest power of two greater than \a value. For negative values it returns 0.
*/
/*!
\fn quint64 qNextPowerOfTwo(quint64 value)
\relates <QtMath>
\since 5.4
This function returns the nearest power of two greater than \a value. For 0 it returns 1, and for values larger than or equal to 2^63 it returns 0.
*/
/*!
\fn quint64 qNextPowerOfTwo(qint64 value)
\relates <QtMath>
\since 5.4
\overload
This function returns the nearest power of two greater than \a value. For negative values it returns 0.
*/

15
src/corelib/tools/qbytearray.cpp
View File

@ -48,6 +48,7 @@
#include "qlocale_p.h"
#include "qscopedpointer.h"
#include <qdatastream.h>
#include <qmath.h>
#ifndef QT_NO_COMPRESS
#include <zlib.h>
@ -72,19 +73,7 @@ int qAllocMore(int alloc, int extra) Q_DECL_NOTHROW
Q_ASSERT(alloc >= 0 && extra >= 0);
Q_ASSERT_X(alloc < (1 << 30) - extra, "qAllocMore", "Requested size is too large!");
unsigned nalloc = alloc + extra;
// Round up to next power of 2
// Assuming container is growing, always overshoot
//--nalloc;
nalloc |= nalloc >> 1;
nalloc |= nalloc >> 2;
nalloc |= nalloc >> 4;
nalloc |= nalloc >> 8;
nalloc |= nalloc >> 16;
++nalloc;
unsigned nalloc = qNextPowerOfTwo(alloc + extra);
Q_ASSERT(nalloc > unsigned(alloc + extra));

19
src/gui/opengl/qopengltexturecache.cpp
View File

@ -40,6 +40,7 @@
****************************************************************************/
#include "qopengltexturecache_p.h"
#include <qmath.h>
#include <qopenglfunctions.h>
#include <private/qopenglcontext_p.h>
#include <private/qimagepixmapcleanuphooks_p.h>
@ -129,20 +130,6 @@ GLuint QOpenGLTextureCache::bindTexture(QOpenGLContext *context, const QPixmap &
return id;
}
// returns the highest number closest to v, which is a power of 2
// NB! assumes 32 bit ints
static int qt_next_power_of_two(int v)
{
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
++v;
return v;
}
GLuint QOpenGLTextureCache::bindTexture(QOpenGLContext *context, const QImage &image)
{
if (image.isNull())
@ -164,8 +151,8 @@ GLuint QOpenGLTextureCache::bindTexture(QOpenGLContext *context, const QImage &i
// Scale the pixmap if needed. GL textures needs to have the
// dimensions 2^n+2(border) x 2^m+2(border), unless we're using GL
// 2.0 or use the GL_TEXTURE_RECTANGLE texture target
int tx_w = qt_next_power_of_two(image.width());
int tx_h = qt_next_power_of_two(image.height());
int tx_w = qNextPowerOfTwo(image.width() - 1);
int tx_h = qNextPowerOfTwo(image.height() - 1);
if (tx_w != image.width() || tx_h != image.height()) {
img = img.scaled(tx_w, tx_h);
}

20
src/gui/painting/qtextureglyphcache.cpp
View File

@ -50,20 +50,6 @@ QT_BEGIN_NAMESPACE
// #define CACHE_DEBUG
// returns the highest number closest to v, which is a power of 2
// NB! assumes 32 bit ints
static inline int qt_next_power_of_two(int v)
{
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
++v;
return v;
}
int QTextureGlyphCache::calculateSubPixelPositionCount(glyph_t glyph) const
{
// Test 12 different subpixel positions since it factors into 3*4 so it gives
@ -199,7 +185,7 @@ bool QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const
if (fontEngine->maxCharWidth() <= QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH)
m_w = QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH;
else
m_w = qt_next_power_of_two(fontEngine->maxCharWidth());
m_w = qNextPowerOfTwo(qCeil(fontEngine->maxCharWidth()) - 1);
}
// now actually use the coords and paint the wanted glyps into cache.
@ -261,9 +247,9 @@ void QTextureGlyphCache::fillInPendingGlyphs()
if (isNull() || requiredHeight > m_h || requiredWidth > m_w) {
if (isNull())
createCache(qt_next_power_of_two(requiredWidth), qt_next_power_of_two(requiredHeight));
createCache(qNextPowerOfTwo(requiredWidth - 1), qNextPowerOfTwo(requiredHeight - 1));
else
resizeCache(qt_next_power_of_two(requiredWidth), qt_next_power_of_two(requiredHeight));
resizeCache(qNextPowerOfTwo(requiredWidth - 1), qNextPowerOfTwo(requiredHeight - 1));
}
{

18
src/opengl/qgl.cpp
View File

@ -1868,20 +1868,6 @@ QImage qt_gl_read_texture(const QSize &size, bool alpha_format, bool include_alp
return img;
}
// returns the highest number closest to v, which is a power of 2
// NB! assumes 32 bit ints
int qt_next_power_of_two(int v)
{
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
++v;
return v;
}
Q_GLOBAL_STATIC(QGLTextureCache, qt_gl_texture_cache)
QGLTextureCache::QGLTextureCache()
@ -2462,8 +2448,8 @@ QGLTexture* QGLContextPrivate::bindTexture(const QImage &image, GLenum target, G
// Scale the pixmap if needed. GL textures needs to have the
// dimensions 2^n+2(border) x 2^m+2(border), unless we're using GL
// 2.0 or use the GL_TEXTURE_RECTANGLE texture target
int tx_w = qt_next_power_of_two(image.width());
int tx_h = qt_next_power_of_two(image.height());
int tx_w = qNextPowerOfTwo(image.width() - 1);
int tx_h = qNextPowerOfTwo(image.height() - 1);
QImage img = image;

119
tests/auto/corelib/kernel/qmath/tst_qmath.cpp
View File

@ -54,6 +54,14 @@ private slots:
void degreesToRadians();
void radiansToDegrees_data();
void radiansToDegrees();
void qNextPowerOfTwo32S_data();
void qNextPowerOfTwo32S();
void qNextPowerOfTwo64S_data();
void qNextPowerOfTwo64S();
void qNextPowerOfTwo32U_data();
void qNextPowerOfTwo32U();
void qNextPowerOfTwo64U_data();
void qNextPowerOfTwo64U();
};
void tst_QMath::fastSinCos()
@ -137,6 +145,117 @@ void tst_QMath::radiansToDegrees()
QCOMPARE(qRadiansToDegrees(radiansDouble), degreesDouble);
}
void tst_QMath::qNextPowerOfTwo32S_data()
{
QTest::addColumn<qint32>("input");
QTest::addColumn<quint32>("output");
QTest::newRow("0") << 0 << 1U;
QTest::newRow("1") << 1 << 2U;
QTest::newRow("2") << 2 << 4U;
QTest::newRow("17") << 17 << 32U;
QTest::newRow("128") << 128 << 256U;
QTest::newRow("65535") << 65535 << 65536U;
QTest::newRow("65536") << 65536 << 131072U;
QTest::newRow("2^30") << (1 << 30) << (1U << 31);
QTest::newRow("2^30 + 1") << (1 << 30) + 1 << (1U << 31);
QTest::newRow("2^31 - 1") << 0x7FFFFFFF << (1U<<31);
QTest::newRow("-1") << -1 << 0U;
QTest::newRow("-128") << -128 << 0U;
QTest::newRow("-(2^31)") << int(0x80000000) << 0U;
}
void tst_QMath::qNextPowerOfTwo32S()
{
QFETCH(qint32, input);
QFETCH(quint32, output);
QCOMPARE(qNextPowerOfTwo(input), output);
}
void tst_QMath::qNextPowerOfTwo32U_data()
{
QTest::addColumn<quint32>("input");
QTest::addColumn<quint32>("output");
QTest::newRow("0") << 0U << 1U;
QTest::newRow("1") << 1U << 2U;
QTest::newRow("2") << 2U << 4U;
QTest::newRow("17") << 17U << 32U;
QTest::newRow("128") << 128U << 256U;
QTest::newRow("65535") << 65535U << 65536U;
QTest::newRow("65536") << 65536U << 131072U;
QTest::newRow("2^30") << (1U << 30) << (1U << 31);
QTest::newRow("2^30 + 1") << (1U << 30) + 1 << (1U << 31);
QTest::newRow("2^31 - 1") << 2147483647U << 2147483648U;
QTest::newRow("2^31") << 2147483648U << 0U;
QTest::newRow("2^31 + 1") << 2147483649U << 0U;
}
void tst_QMath::qNextPowerOfTwo32U()
{
QFETCH(quint32, input);
QFETCH(quint32, output);
QCOMPARE(qNextPowerOfTwo(input), output);
}
void tst_QMath::qNextPowerOfTwo64S_data()
{
QTest::addColumn<qint64>("input");
QTest::addColumn<quint64>("output");
QTest::newRow("0") << Q_INT64_C(0) << Q_UINT64_C(1);
QTest::newRow("1") << Q_INT64_C(1) << Q_UINT64_C(2);
QTest::newRow("2") << Q_INT64_C(2) << Q_UINT64_C(4);
QTest::newRow("17") << Q_INT64_C(17) << Q_UINT64_C(32);
QTest::newRow("128") << Q_INT64_C(128) << Q_UINT64_C(256);
QTest::newRow("65535") << Q_INT64_C(65535) << Q_UINT64_C(65536);
QTest::newRow("65536") << Q_INT64_C(65536) << Q_UINT64_C(131072);
QTest::newRow("2^31 - 1") << Q_INT64_C(2147483647) << Q_UINT64_C(0x80000000);
QTest::newRow("2^31") << Q_INT64_C(2147483648) << Q_UINT64_C(0x100000000);
QTest::newRow("2^31 + 1") << Q_INT64_C(2147483649) << Q_UINT64_C(0x100000000);
QTest::newRow("2^63 - 1") << Q_INT64_C(0x7FFFFFFFFFFFFFFF) << Q_UINT64_C(0x8000000000000000);
QTest::newRow("-1") << Q_INT64_C(-1) << Q_UINT64_C(0);
QTest::newRow("-128") << Q_INT64_C(-128) << Q_UINT64_C(0);
QTest::newRow("-(2^31)") << -Q_INT64_C(0x80000000) << Q_UINT64_C(0);
QTest::newRow("-(2^63)") << (qint64)Q_INT64_C(0x8000000000000000) << Q_UINT64_C(0);
}
void tst_QMath::qNextPowerOfTwo64S()
{
QFETCH(qint64, input);
QFETCH(quint64, output);
QCOMPARE(qNextPowerOfTwo(input), output);
}
void tst_QMath::qNextPowerOfTwo64U_data()
{
QTest::addColumn<quint64>("input");
QTest::addColumn<quint64>("output");
QTest::newRow("0") << Q_UINT64_C(0) << Q_UINT64_C(1);
QTest::newRow("1") << Q_UINT64_C(1) << Q_UINT64_C(2);
QTest::newRow("2") << Q_UINT64_C(2) << Q_UINT64_C(4);
QTest::newRow("17") << Q_UINT64_C(17) << Q_UINT64_C(32);
QTest::newRow("128") << Q_UINT64_C(128) << Q_UINT64_C(256);
QTest::newRow("65535") << Q_UINT64_C(65535) << Q_UINT64_C(65536);
QTest::newRow("65536") << Q_UINT64_C(65536) << Q_UINT64_C(131072);
QTest::newRow("2^63 - 1") << Q_UINT64_C(0x7FFFFFFFFFFFFFFF) << Q_UINT64_C(0x8000000000000000);
QTest::newRow("2^63") << Q_UINT64_C(0x8000000000000000) << Q_UINT64_C(0);
QTest::newRow("2^63 + 1") << Q_UINT64_C(0x8000000000000001) << Q_UINT64_C(0);
}
void tst_QMath::qNextPowerOfTwo64U()
{
QFETCH(quint64, input);
QFETCH(quint64, output);
QCOMPARE(qNextPowerOfTwo(input), output);
}
QTEST_APPLESS_MAIN(tst_QMath)
#include "tst_qmath.moc"