summaryrefslogtreecommitdiffstats
path: root/src/gui/image/qimage_ssse3.cpp
blob: 9cdfba20e3df19bc3d8d01fdb600c40cc6d6088c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/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 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include <qimage.h>
#include <private/qimage_p.h>
#include <private/qsimd_p.h>

#ifdef QT_COMPILER_SUPPORTS_SSSE3

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
Q_GUI_EXPORT void QT_FASTCALL qt_convert_rgb888_to_rgb32_ssse3(quint32 *dst, const uchar *src, int len)
{
    int i = 0;

    // Prologue, align dst to 16 bytes.
    ALIGNMENT_PROLOGUE_16BYTES(dst, i, len) {
        dst[i] = qRgb(src[0], src[1], src[2]);
        src += 3;
    }

    // Mask the 4 first colors of the RGB888 vector
    const __m128i shuffleMask = _mm_set_epi8(char(0xff), 9, 10, 11, char(0xff), 6, 7, 8, char(0xff), 3, 4, 5, char(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(char(0xff), 13, 14, 15, char(0xff), 10, 11, 12, char(0xff), 7, 8, 9, char(0xff), 4, 5, 6);

    // Mask to have alpha = 0xff
    const __m128i alphaMask = _mm_set1_epi32(0xff000000);

    const __m128i *inVectorPtr = (const __m128i *)src;
    __m128i *dstVectorPtr = (__m128i *)(dst + i);

    for (; i < (len - 15); i += 16) { // one iteration in the loop converts 16 pixels
        /*
         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 = (const uchar *)inVectorPtr;

    SIMD_EPILOGUE(i, len, 15) {
        dst[i] = 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) {
        qt_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_COMPILER_SUPPORTS_SSSE3