From 8b16557c35cb03229aca68b9e6385e776c82a7b7 Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Mon, 29 Jan 2018 14:19:14 +0100
Subject: [PATCH] Avoid destStore64 when pixels are just repeating

The destStore64 operation can be expensive, so when the pixels are just
repeating, avoid using it and the composition, and just repeat the
first generated part.

Change-Id: I6e21594a9abecdc245010b956acbaa60e3fb21a3
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>
---
 src/gui/painting/qdrawhelper.cpp | 57 ++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/src/gui/painting/qdrawhelper.cpp b/src/gui/painting/qdrawhelper.cpp
index efd9b0c146c..3b115daf86b 100644
--- a/src/gui/painting/qdrawhelper.cpp
+++ b/src/gui/painting/qdrawhelper.cpp
@@ -3801,10 +3801,23 @@ void blend_color_generic_rgb64(int count, const QSpan *spans, void *userData)
 
     quint64 buffer[BufferSize];
     const QRgba64 color = data->solid.color;
+    bool solidFill = data->rasterBuffer->compositionMode == QPainter::CompositionMode_Source
+                  || (data->rasterBuffer->compositionMode == QPainter::CompositionMode_SourceOver && color.isOpaque());
+    bool isBpp32 = qPixelLayouts[data->rasterBuffer->format].bpp == QPixelLayout::BPP32;
 
     while (count--) {
         int x = spans->x;
         int length = spans->len;
+        if (solidFill && isBpp32 && spans->coverage == 255) {
+            // If dest doesn't matter we don't need to bother with blending or converting all the identical pixels
+            if (length > 0) {
+                op.destStore64(data->rasterBuffer, x, spans->y, &color, 1);
+                uint *dest = (uint*)data->rasterBuffer->scanLine(spans->y) + x;
+                qt_memfill32(dest + 1, dest[0], length - 1);
+                length = 0;
+            }
+        }
+
         while (length) {
             int l = qMin(BufferSize, length);
             QRgba64 *dest = op.destFetch64((QRgba64 *)buffer, data->rasterBuffer, x, spans->y, l);
@@ -4347,6 +4360,50 @@ static void blend_tiled_generic_rgb64(int count, const QSpan *spans, void *userD
     if (yoff < 0)
         yoff += image_height;
 
+    bool isBpp32 = qPixelLayouts[data->rasterBuffer->format].bpp == QPixelLayout::BPP32;
+    if (op.destFetch64 == destFetch64Undefined && image_width <= BufferSize && isBpp32) {
+        // If destination isn't blended into the result, we can do the tiling directly on destination pixels.
+        while (count--) {
+            int x = spans->x;
+            int y = spans->y;
+            int length = spans->len;
+            int sx = (xoff + spans->x) % image_width;
+            int sy = (spans->y + yoff) % image_height;
+            if (sx < 0)
+                sx += image_width;
+            if (sy < 0)
+                sy += image_height;
+
+            int sl = qMin(image_width, length);
+            if (sx > 0 && sl > 0) {
+                int l = qMin(image_width - sx, sl);
+                const QRgba64 *src = op.srcFetch64((QRgba64 *)src_buffer, &op, data, sy, sx, l);
+                op.destStore64(data->rasterBuffer, x, y, src, l);
+                x += l;
+                sx += l;
+                sl -= l;
+                if (sx >= image_width)
+                    sx = 0;
+            }
+            if (sl > 0) {
+                Q_ASSERT(sx == 0);
+                const QRgba64 *src = op.srcFetch64((QRgba64 *)src_buffer, &op, data, sy, sx, sl);
+                op.destStore64(data->rasterBuffer, x, y, src, sl);
+                x += sl;
+                sx += sl;
+                sl -= sl;
+                if (sx >= image_width)
+                    sx = 0;
+            }
+            uint *dest = (uint*)data->rasterBuffer->scanLine(y) + x - image_width;
+            for (int i = image_width; i < length; ++i) {
+                dest[i] = dest[i - image_width];
+            }
+            ++spans;
+        }
+        return;
+    }
+
     while (count--) {
         int x = spans->x;
         int length = spans->len;