From 90642dd2b6b14c39cc6178f1161331895809b342 Mon Sep 17 00:00:00 2001 From: Benjamin Poulain Date: Fri, 23 Jul 2010 16:14:49 +0200 Subject: Use SSSE3 to convert from RGB888 to RGB32 Converting from RGB encoded on 24bits to RGB encoded on 32 bits is quite inefficient. This type of conversion is common for some image format. The patch implement the conversion with SSSE3. This reduce by 3 the number of instructions, pushing the bottleneck to memory bandwidth. On Atom N450, the new benchmark is 40% faster for scanlines of 2000 pixels, 30% faster for scanlines of 32 pixels, and 15% slower for small images (3 and 8px). Reviewed-by: Olivier Goffart --- src/gui/image/image.pri | 1 + src/gui/image/qimage.cpp | 10 +- src/gui/image/qimage_ssse3.cpp | 150 +++++++++++++++++++++ tests/auto/qimage/tst_qimage.cpp | 22 +++ tests/benchmarks/gui/image/image.pro | 1 + .../image/qimageconversion/qimageconversion.pro | 10 ++ .../qimageconversion/tst_qimageconversion.cpp | 108 +++++++++++++++ 7 files changed, 301 insertions(+), 1 deletion(-) create mode 100644 src/gui/image/qimage_ssse3.cpp create mode 100644 tests/benchmarks/gui/image/qimageconversion/qimageconversion.pro create mode 100644 tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp diff --git a/src/gui/image/image.pri b/src/gui/image/image.pri index 3a02d56..b20a04f 100644 --- a/src/gui/image/image.pri +++ b/src/gui/image/image.pri @@ -95,3 +95,4 @@ contains(QT_CONFIG, gif):include($$PWD/qgifhandler.pri) # SIMD SSE2_SOURCES += image/qimage_sse2.cpp +SSSE3_SOURCES += image/qimage_ssse3.cpp diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp index 713e765..30cf758 100644 --- a/src/gui/image/qimage.cpp +++ b/src/gui/image/qimage.cpp @@ -3354,7 +3354,7 @@ CONVERT_DECL(qargb4444, quint32) // first index source, second dest -static const Image_Converter converter_map[QImage::NImageFormats][QImage::NImageFormats] = +static Image_Converter converter_map[QImage::NImageFormats][QImage::NImageFormats] = { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 @@ -3761,6 +3761,14 @@ void qInitImageConversions() inplace_converter_map[QImage::Format_ARGB32][QImage::Format_ARGB32_Premultiplied] = convert_ARGB_to_ARGB_PM_inplace_sse2; } #endif +#ifdef QT_HAVE_SSSE3 + if (features & SSSE3) { + extern void convert_RGB888_to_RGB32_ssse3(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags); + converter_map[QImage::Format_RGB888][QImage::Format_RGB32] = convert_RGB888_to_RGB32_ssse3; + converter_map[QImage::Format_RGB888][QImage::Format_ARGB32] = convert_RGB888_to_RGB32_ssse3; + converter_map[QImage::Format_RGB888][QImage::Format_ARGB32_Premultiplied] = convert_RGB888_to_RGB32_ssse3; + } +#endif } /*! diff --git a/src/gui/image/qimage_ssse3.cpp b/src/gui/image/qimage_ssse3.cpp new file mode 100644 index 0000000..1c664f2 --- /dev/null +++ b/src/gui/image/qimage_ssse3.cpp @@ -0,0 +1,150 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtGui module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** 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. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include +#include +#include + +#ifdef QT_HAVE_SSSE3 + +#include +QT_BEGIN_NAMESPACE + +// Convert a scanline of RGB888 (src) to RGB32 (dst) +// src must be at least len * 3 bytes +// dst must be at least len * 4 bytes +inline void convert_rgb888_to_rgb32_ssse3(quint32 *dst, const uchar *src, int len) +{ + quint32 *const end = dst + len; + + // Prologue, align dst to 16 bytes. The alignement is done on dst because it has 4 store() + // for each 3 load() of src. + const int offsetToAlignOn16Bytes = (4 - ((reinterpret_cast(dst) >> 2) & 0x3)) & 0x3; + const int prologLength = qMin(len, offsetToAlignOn16Bytes); + + for (int i = 0; i < prologLength; ++i) { + *dst++ = qRgb(src[0], src[1], src[2]); + src += 3; + } + + // Mask the 4 first colors of the RGB888 vector + const __m128i shuffleMask = _mm_set_epi8(0xff, 9, 10, 11, 0xff, 6, 7, 8, 0xff, 3, 4, 5, 0xff, 0, 1, 2); + + // Mask the 4 last colors of a RGB888 vector with an offset of 1 (so the last 3 bytes are RGB) + const __m128i shuffleMaskEnd = _mm_set_epi8(0xff, 13, 14, 15, 0xff, 10, 11, 12, 0xff, 7, 8, 9, 0xff, 4, 5, 6); + + // Mask to have alpha = 0xff + const __m128i alphaMask = _mm_set1_epi32(0xff000000); + + __m128i *inVectorPtr = (__m128i *)src; + __m128i *dstVectorPtr = (__m128i *)dst; + + const int simdRoundCount = (len - prologLength) / 16; // one iteration in the loop converts 16 pixels + for (int i = 0; i < simdRoundCount; ++i) { + /* + RGB888 has 5 pixels per vector, + 1 byte from the next pixel. The idea here is + to load vectors of RGB888 and use palignr to select a vector out of two vectors. + + After 3 loads of RGB888 and 3 stores of RGB32, we have 4 pixels left in the last + vector of RGB888, we can mask it directly to get a last store or RGB32. After that, + the first next byte is a R, and we can loop for the next 16 pixels. + + The conversion itself is done with a byte permutation (pshufb). + */ + __m128i firstSrcVector = _mm_lddqu_si128(inVectorPtr); + __m128i outputVector = _mm_shuffle_epi8(firstSrcVector, shuffleMask); + _mm_store_si128(dstVectorPtr, _mm_or_si128(outputVector, alphaMask)); + ++inVectorPtr; + ++dstVectorPtr; + + // There are 4 unused bytes left in srcVector, we need to load the next 16 bytes + // and load the next input with palignr + __m128i secondSrcVector = _mm_lddqu_si128(inVectorPtr); + __m128i srcVector = _mm_alignr_epi8(secondSrcVector, firstSrcVector, 12); + outputVector = _mm_shuffle_epi8(srcVector, shuffleMask); + _mm_store_si128(dstVectorPtr, _mm_or_si128(outputVector, alphaMask)); + ++inVectorPtr; + ++dstVectorPtr; + firstSrcVector = secondSrcVector; + + // We now have 8 unused bytes left in firstSrcVector + secondSrcVector = _mm_lddqu_si128(inVectorPtr); + srcVector = _mm_alignr_epi8(secondSrcVector, firstSrcVector, 8); + outputVector = _mm_shuffle_epi8(srcVector, shuffleMask); + _mm_store_si128(dstVectorPtr, _mm_or_si128(outputVector, alphaMask)); + ++inVectorPtr; + ++dstVectorPtr; + + // There are now 12 unused bytes in firstSrcVector. + // We can mask them directly, almost there. + outputVector = _mm_shuffle_epi8(secondSrcVector, shuffleMaskEnd); + _mm_store_si128(dstVectorPtr, _mm_or_si128(outputVector, alphaMask)); + ++dstVectorPtr; + } + src = (uchar *)inVectorPtr; + dst = (quint32 *)dstVectorPtr; + + while (dst != end) { + *dst++ = qRgb(src[0], src[1], src[2]); + src += 3; + } +} + +void convert_RGB888_to_RGB32_ssse3(QImageData *dest, const QImageData *src, Qt::ImageConversionFlags) +{ + Q_ASSERT(src->format == QImage::Format_RGB888); + Q_ASSERT(dest->format == QImage::Format_RGB32 || dest->format == QImage::Format_ARGB32 || dest->format == QImage::Format_ARGB32_Premultiplied); + Q_ASSERT(src->width == dest->width); + Q_ASSERT(src->height == dest->height); + + const uchar *src_data = (uchar *) src->data; + quint32 *dest_data = (quint32 *) dest->data; + + for (int i = 0; i < src->height; ++i) { + convert_rgb888_to_rgb32_ssse3(dest_data, src_data, src->width); + src_data += src->bytes_per_line; + dest_data = (quint32 *)((uchar*)dest_data + dest->bytes_per_line); + } +} + +QT_END_NAMESPACE + +#endif // QT_HAVE_SSSE3 diff --git a/tests/auto/qimage/tst_qimage.cpp b/tests/auto/qimage/tst_qimage.cpp index 5052114..1330d96 100644 --- a/tests/auto/qimage/tst_qimage.cpp +++ b/tests/auto/qimage/tst_qimage.cpp @@ -83,6 +83,8 @@ private slots: void convertToFormat_data(); void convertToFormat(); + void convertToFormatRgb888ToRGB32(); + void createAlphaMask_data(); void createAlphaMask(); #ifndef QT_NO_IMAGE_HEURISTIC_MASK @@ -799,6 +801,26 @@ void tst_QImage::convertToFormat() QFile::remove(QLatin1String("expected2.xpm")); } +void tst_QImage::convertToFormatRgb888ToRGB32() +{ + // 545 so width % 4 != 0. This ensure there is padding at the end of the scanlines + const int height = 545; + const int width = 545; + QImage source(width, height, QImage::Format_RGB888); + for (int y = 0; y < height; ++y) { + uchar *srcPixels = source.scanLine(y); + for (int x = 0; x < width * 3; ++x) + srcPixels[x] = x; + } + + QImage rgb32Image = source.convertToFormat(QImage::Format_RGB888); + QCOMPARE(rgb32Image.format(), QImage::Format_RGB888); + for (int x = 0; x < width; ++x) { + for (int y = 0; y < height; ++y) + QCOMPARE(rgb32Image.pixel(x, y), source.pixel(x, y)); + } +} + void tst_QImage::createAlphaMask_data() { QTest::addColumn("x"); diff --git a/tests/benchmarks/gui/image/image.pro b/tests/benchmarks/gui/image/image.pro index 3094e72..a8c6732 100644 --- a/tests/benchmarks/gui/image/image.pro +++ b/tests/benchmarks/gui/image/image.pro @@ -1,6 +1,7 @@ TEMPLATE = subdirs SUBDIRS = \ blendbench \ + qimageconversion \ qimagereader \ qpixmap \ qpixmapcache diff --git a/tests/benchmarks/gui/image/qimageconversion/qimageconversion.pro b/tests/benchmarks/gui/image/qimageconversion/qimageconversion.pro new file mode 100644 index 0000000..ec50d98 --- /dev/null +++ b/tests/benchmarks/gui/image/qimageconversion/qimageconversion.pro @@ -0,0 +1,10 @@ +load(qttest_p4) +TEMPLATE = app +TARGET = tst_bench_imageConversion + +SOURCES += tst_qimageconversion.cpp + +!contains(QT_CONFIG, no-gif):DEFINES += QTEST_HAVE_GIF +!contains(QT_CONFIG, no-jpeg):DEFINES += QTEST_HAVE_JPEG +!contains(QT_CONFIG, no-mng):DEFINES += QTEST_HAVE_MNG +!contains(QT_CONFIG, no-tiff):DEFINES += QTEST_HAVE_TIFF diff --git a/tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp b/tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp new file mode 100644 index 0000000..1c76d46 --- /dev/null +++ b/tests/benchmarks/gui/image/qimageconversion/tst_qimageconversion.cpp @@ -0,0 +1,108 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the test suite of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** 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. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include +#include + +Q_DECLARE_METATYPE(QImage) + +class tst_QImageConversion : public QObject +{ + Q_OBJECT +private slots: + void convertRgb888ToRGB32_data(); + void convertRgb888ToRGB32(); + +private: + QImage generateImageRgb888(int width, int height); +}; + +void tst_QImageConversion::convertRgb888ToRGB32_data() +{ + QTest::addColumn("inputImage"); + // height = 5000 to get interesting timing. + + // 3 pixels wide -> smaller than regular vector of 128bits + QTest::newRow("width: 3px; height: 5000px;") << generateImageRgb888(3, 5000); + + // 8 pixels wide -> potential for 2 vectors + QTest::newRow("width: 8px; height: 5000px;") << generateImageRgb888(3, 5000); + + // 16 pixels, minimum for the SSSE3 implementation + QTest::newRow("width: 16px; height: 5000px;") << generateImageRgb888(16, 5000); + + // 50 pixels, more realistic use case + QTest::newRow("width: 50px; height: 5000px;") << generateImageRgb888(50, 5000); + + // 2000 pixels -> typical values for pictures + QTest::newRow("width: 2000px; height: 5000px;") << generateImageRgb888(2000, 5000); +} + +void tst_QImageConversion::convertRgb888ToRGB32() +{ + QFETCH(QImage, inputImage); + + QBENCHMARK { + volatile QImage output = inputImage.convertToFormat(QImage::Format_RGB32); + // we need the volatile and the following to make sure the compiler does not do + // anything stupid :) + (void)output; + } +} + +/* + Fill a RGB888 image with "random" pixel values. + */ +QImage tst_QImageConversion::generateImageRgb888(int width, int height) +{ + QImage image(width, height, QImage::Format_RGB888); + const int byteWidth = width * 3; + + for (int y = 0; y < image.height(); ++y) { + uchar *scanline = image.scanLine(y); + for (int x = 0; x < byteWidth; ++x) + scanline[x] = x ^ y; + } + return image; +} + +QTEST_MAIN(tst_QImageConversion) +#include "tst_qimageconversion.moc" -- cgit v0.12