NEON optimized qimagescale

Adds a NEON optimized version of the QImage smooth scaling.

Change-Id: I27c0a24d25f66bda3b5c55a8fabdb8b583fcd5c6
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

3 files changed, 246 insertions, 1 deletions

diff --git a/src/gui/painting/painting.pri b/src/gui/painting/painting.pri
index 5b25c2fd95..45eb8ccbab 100644
--- a/src/gui/painting/painting.pri
+++ b/src/gui/painting/painting.pri
@@ -103,7 +103,7 @@ AVX2_SOURCES += painting/qdrawhelper_avx2.cpp
 
 !ios {
     CONFIG += no_clang_integrated_as
-    NEON_SOURCES += painting/qdrawhelper_neon.cpp
+    NEON_SOURCES += painting/qdrawhelper_neon.cpp painting/qimagescale_neon.cpp
     NEON_HEADERS += painting/qdrawhelper_neon_p.h
     !contains(QT_ARCH, "arm64"): NEON_ASM += ../3rdparty/pixman/pixman-arm-neon-asm.S painting/qdrawhelper_neon_asm.S
 }
diff --git a/src/gui/painting/qimagescale.cpp b/src/gui/painting/qimagescale.cpp
index 33dccc5374..d51d0bf4a8 100644
--- a/src/gui/painting/qimagescale.cpp
+++ b/src/gui/painting/qimagescale.cpp
@@ -277,6 +277,18 @@ void qt_qimageScaleAARGBA_down_xy_sse4(QImageScaleInfo *isi, unsigned int *dest,
                                        int dw, int dh, int dow, int sow);
 #endif
 
+#if defined(__ARM_NEON__)
+template<bool RGB>
+void qt_qimageScaleAARGBA_up_x_down_y_neon(QImageScaleInfo *isi, unsigned int *dest,
+                                           int dw, int dh, int dow, int sow);
+template<bool RGB>
+void qt_qimageScaleAARGBA_down_x_up_y_neon(QImageScaleInfo *isi, unsigned int *dest,
+                                           int dw, int dh, int dow, int sow);
+template<bool RGB>
+void qt_qimageScaleAARGBA_down_xy_neon(QImageScaleInfo *isi, unsigned int *dest,
+                                       int dw, int dh, int dow, int sow);
+#endif
+
 static void qt_qimageScaleAARGBA_up_xy(QImageScaleInfo *isi, unsigned int *dest,
                                        int dw, int dh, int dow, int sow)
 {
@@ -329,6 +341,10 @@ static void qt_qimageScaleAARGBA(QImageScaleInfo *isi, unsigned int *dest,
         if (qCpuHasFeature(SSE4_1))
             qt_qimageScaleAARGBA_up_x_down_y_sse4<false>(isi, dest, dw, dh, dow, sow);
         else
+#elif defined(__ARM_NEON__)
+        if (qCpuHasFeature(NEON))
+            qt_qimageScaleAARGBA_up_x_down_y_neon<false>(isi, dest, dw, dh, dow, sow);
+        else
 #endif
         qt_qimageScaleAARGBA_up_x_down_y(isi, dest, dw, dh, dow, sow);
     }
@@ -338,6 +354,10 @@ static void qt_qimageScaleAARGBA(QImageScaleInfo *isi, unsigned int *dest,
         if (qCpuHasFeature(SSE4_1))
             qt_qimageScaleAARGBA_down_x_up_y_sse4<false>(isi, dest, dw, dh, dow, sow);
         else
+#elif defined(__ARM_NEON__)
+        if (qCpuHasFeature(NEON))
+            qt_qimageScaleAARGBA_down_x_up_y_neon<false>(isi, dest, dw, dh, dow, sow);
+        else
 #endif
         qt_qimageScaleAARGBA_down_x_up_y(isi, dest, dw, dh, dow, sow);
     }
@@ -347,6 +367,10 @@ static void qt_qimageScaleAARGBA(QImageScaleInfo *isi, unsigned int *dest,
         if (qCpuHasFeature(SSE4_1))
             qt_qimageScaleAARGBA_down_xy_sse4<false>(isi, dest, dw, dh, dow, sow);
         else
+#elif defined(__ARM_NEON__)
+        if (qCpuHasFeature(NEON))
+            qt_qimageScaleAARGBA_down_xy_neon<false>(isi, dest, dw, dh, dow, sow);
+        else
 #endif
         qt_qimageScaleAARGBA_down_xy(isi, dest, dw, dh, dow, sow);
     }
@@ -522,6 +546,10 @@ static void qt_qimageScaleAARGB(QImageScaleInfo *isi, unsigned int *dest,
         if (qCpuHasFeature(SSE4_1))
             qt_qimageScaleAARGBA_up_x_down_y_sse4<true>(isi, dest, dw, dh, dow, sow);
         else
+#elif defined(__ARM_NEON__)
+        if (qCpuHasFeature(NEON))
+            qt_qimageScaleAARGBA_up_x_down_y_neon<true>(isi, dest, dw, dh, dow, sow);
+        else
 #endif
         qt_qimageScaleAARGB_up_x_down_y(isi, dest, dw, dh, dow, sow);
     }
@@ -531,6 +559,10 @@ static void qt_qimageScaleAARGB(QImageScaleInfo *isi, unsigned int *dest,
         if (qCpuHasFeature(SSE4_1))
             qt_qimageScaleAARGBA_down_x_up_y_sse4<true>(isi, dest, dw, dh, dow, sow);
         else
+#elif defined(__ARM_NEON__)
+        if (qCpuHasFeature(NEON))
+            qt_qimageScaleAARGBA_down_x_up_y_neon<true>(isi, dest, dw, dh, dow, sow);
+        else
 #endif
         qt_qimageScaleAARGB_down_x_up_y(isi, dest, dw, dh, dow, sow);
     }
@@ -540,6 +572,10 @@ static void qt_qimageScaleAARGB(QImageScaleInfo *isi, unsigned int *dest,
         if (qCpuHasFeature(SSE4_1))
             qt_qimageScaleAARGBA_down_xy_sse4<true>(isi, dest, dw, dh, dow, sow);
         else
+#elif defined(__ARM_NEON__)
+        if (qCpuHasFeature(NEON))
+            qt_qimageScaleAARGBA_down_xy_neon<true>(isi, dest, dw, dh, dow, sow);
+        else
 #endif
         qt_qimageScaleAARGB_down_xy(isi, dest, dw, dh, dow, sow);
     }
diff --git a/src/gui/painting/qimagescale_neon.cpp b/src/gui/painting/qimagescale_neon.cpp
new file mode 100644
index 0000000000..88389bebb9
--- /dev/null
+++ b/src/gui/painting/qimagescale_neon.cpp
@@ -0,0 +1,209 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** 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 The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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 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.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qimagescale_p.h"
+#include "qimage.h"
+#include <private/qsimd_p.h>
+
+#if defined(__ARM_NEON__)
+
+QT_BEGIN_NAMESPACE
+
+using namespace QImageScale;
+
+inline static uint32x4_t qt_qimageScaleAARGBA_helper(const unsigned int *pix, int xyap, int Cxy, int step)
+{
+    uint32x2_t vpix32 = vmov_n_u32(*pix);
+    uint16x4_t vpix16 = vget_low_u16(vmovl_u8(vreinterpret_u8_u32(vpix32)));
+    uint32x4_t vx = vmull_n_u16(vpix16, xyap);
+    int i;
+    for (i = (1 << 14) - xyap; i > Cxy; i -= Cxy) {
+        pix += step;
+        vpix32 = vmov_n_u32(*pix);
+        vpix16 = vget_low_u16(vmovl_u8(vreinterpret_u8_u32(vpix32)));
+        vx = vaddq_u32(vx, vmull_n_u16(vpix16, Cxy));
+    }
+    pix += step;
+    vpix32 = vmov_n_u32(*pix);
+    vpix16 = vget_low_u16(vmovl_u8(vreinterpret_u8_u32(vpix32)));
+    vx = vaddq_u32(vx, vmull_n_u16(vpix16, i));
+    return vx;
+}
+
+template<bool RGB>
+void qt_qimageScaleAARGBA_up_x_down_y_neon(QImageScaleInfo *isi, unsigned int *dest,
+                                           int dw, int dh, int dow, int sow)
+{
+    const unsigned int **ypoints = isi->ypoints;
+    int *xpoints = isi->xpoints;
+    int *xapoints = isi->xapoints;
+    int *yapoints = isi->yapoints;
+
+    /* go through every scanline in the output buffer */
+    for (int y = 0; y < dh; y++) {
+        int Cy = yapoints[y] >> 16;
+        int yap = yapoints[y] & 0xffff;
+
+        unsigned int *dptr = dest + (y * dow);
+        for (int x = 0; x < dw; x++) {
+            const unsigned int *sptr = ypoints[y] + xpoints[x];
+            uint32x4_t vx = qt_qimageScaleAARGBA_helper(sptr, yap, Cy, sow);
+
+            int xap = xapoints[x];
+            if (xap > 0) {
+                uint32x4_t vr = qt_qimageScaleAARGBA_helper(sptr + 1, yap, Cy, sow);
+
+                vx = vmulq_n_u32(vx, 256 - xap);
+                vr = vmulq_n_u32(vr, xap);
+                vx = vaddq_u32(vx, vr);
+                vx = vshrq_n_u32(vx, 8);
+            }
+            vx = vshrq_n_u32(vx, 14);
+            const uint16x4_t vx16 = vmovn_u32(vx);
+            const uint8x8_t vx8 = vmovn_u16(vcombine_u16(vx16, vx16));
+            *dptr = vget_lane_u32(vreinterpret_u32_u8(vx8), 0);
+            if (RGB)
+                *dptr |= 0xff000000;
+            dptr++;
+        }
+    }
+}
+
+template<bool RGB>
+void qt_qimageScaleAARGBA_down_x_up_y_neon(QImageScaleInfo *isi, unsigned int *dest,
+                                           int dw, int dh, int dow, int sow)
+{
+    const unsigned int **ypoints = isi->ypoints;
+    int *xpoints = isi->xpoints;
+    int *xapoints = isi->xapoints;
+    int *yapoints = isi->yapoints;
+
+    /* go through every scanline in the output buffer */
+    for (int y = 0; y < dh; y++) {
+        unsigned int *dptr = dest + (y * dow);
+        for (int x = 0; x < dw; x++) {
+            int Cx = xapoints[x] >> 16;
+            int xap = xapoints[x] & 0xffff;
+
+            const unsigned int *sptr = ypoints[y] + xpoints[x];
+            uint32x4_t vx = qt_qimageScaleAARGBA_helper(sptr, xap, Cx, 1);
+
+            int yap = yapoints[y];
+            if (yap > 0) {
+                uint32x4_t vr = qt_qimageScaleAARGBA_helper(sptr + sow, xap, Cx, 1);
+
+                vx = vmulq_n_u32(vx, 256 - yap);
+                vr = vmulq_n_u32(vr, yap);
+                vx = vaddq_u32(vx, vr);
+                vx = vshrq_n_u32(vx, 8);
+            }
+            vx = vshrq_n_u32(vx, 14);
+            const uint16x4_t vx16 = vmovn_u32(vx);
+            const uint8x8_t vx8 = vmovn_u16(vcombine_u16(vx16, vx16));
+            *dptr = vget_lane_u32(vreinterpret_u32_u8(vx8), 0);
+            if (RGB)
+                *dptr |= 0xff000000;
+            dptr++;
+        }
+    }
+}
+
+template<bool RGB>
+void qt_qimageScaleAARGBA_down_xy_neon(QImageScaleInfo *isi, unsigned int *dest,
+                                       int dw, int dh, int dow, int sow)
+{
+    const unsigned int **ypoints = isi->ypoints;
+    int *xpoints = isi->xpoints;
+    int *xapoints = isi->xapoints;
+    int *yapoints = isi->yapoints;
+
+    for (int y = 0; y < dh; y++) {
+        int Cy = yapoints[y] >> 16;
+        int yap = yapoints[y] & 0xffff;
+
+        unsigned int *dptr = dest + (y * dow);
+        for (int x = 0; x < dw; x++) {
+            const int Cx = xapoints[x] >> 16;
+            const int xap = xapoints[x] & 0xffff;
+
+            const unsigned int *sptr = ypoints[y] + xpoints[x];
+            uint32x4_t vx = qt_qimageScaleAARGBA_helper(sptr, xap, Cx, 1);
+            vx = vshrq_n_u32(vx, 4);
+            uint32x4_t vr = vmulq_n_u32(vx, yap);
+
+            int j;
+            for (j = (1 << 14) - yap; j > Cy; j -= Cy) {
+                sptr += sow;
+                vx = qt_qimageScaleAARGBA_helper(sptr, xap, Cx, 1);
+                vx = vshrq_n_u32(vx, 4);
+                vx = vmulq_n_u32(vx, Cy);
+                vr = vaddq_u32(vr, vx);
+            }
+            sptr += sow;
+            vx = qt_qimageScaleAARGBA_helper(sptr, xap, Cx, 1);
+            vx = vshrq_n_u32(vx, 4);
+            vx = vmulq_n_u32(vx, j);
+            vr = vaddq_u32(vr, vx);
+
+            vx = vshrq_n_u32(vr, 24);
+            const uint16x4_t vx16 = vmovn_u32(vx);
+            const uint8x8_t vx8 = vmovn_u16(vcombine_u16(vx16, vx16));
+            *dptr = vget_lane_u32(vreinterpret_u32_u8(vx8), 0);
+            if (RGB)
+                *dptr |= 0xff000000;
+            dptr++;
+        }
+    }
+}
+
+template void qt_qimageScaleAARGBA_up_x_down_y_neon<false>(QImageScaleInfo *isi, unsigned int *dest,
+                                                           int dw, int dh, int dow, int sow);
+
+template void qt_qimageScaleAARGBA_up_x_down_y_neon<true>(QImageScaleInfo *isi, unsigned int *dest,
+                                                          int dw, int dh, int dow, int sow);
+
+template void qt_qimageScaleAARGBA_down_x_up_y_neon<false>(QImageScaleInfo *isi, unsigned int *dest,
+                                                           int dw, int dh, int dow, int sow);
+
+template void qt_qimageScaleAARGBA_down_x_up_y_neon<true>(QImageScaleInfo *isi, unsigned int *dest,
+                                                          int dw, int dh, int dow, int sow);
+
+template void qt_qimageScaleAARGBA_down_xy_neon<false>(QImageScaleInfo *isi, unsigned int *dest,
+                                                       int dw, int dh, int dow, int sow);
+
+template void qt_qimageScaleAARGBA_down_xy_neon<true>(QImageScaleInfo *isi, unsigned int *dest,
+                                                      int dw, int dh, int dow, int sow);
+
+QT_END_NAMESPACE
+
+#endif