From ec93973158726f7a4c193cd0ed648c12011a6be6 Mon Sep 17 00:00:00 2001
From: MacDue <macdue@dueutil.tech>
Date: Sat, 6 Jan 2024 13:52:34 +0000
Subject: [PATCH] LibGfx: Sprinkle some FLATTEN/hot attributes in the path
 rasterizer

This seems to actually improve performance to the tune of about +5 fps.
---
 Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.cpp | 6 +++---
 Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.h   | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.cpp b/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.cpp
index 851ea934e5..372df98680 100644
--- a/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.cpp
+++ b/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.cpp
@@ -167,7 +167,7 @@ void EdgeFlagPathRasterizer<SamplesPerPixel>::fill_internal(Painter& painter, Pa
     auto for_each_sample = [&](Detail::Edge& edge, int start_subpixel_y, int end_subpixel_y, EdgeExtent& edge_extent, auto callback) {
         for (int y = start_subpixel_y; y < end_subpixel_y; y++) {
             auto xi = static_cast<int>(edge.x + SubpixelSample::nrooks_subpixel_offsets[y]);
-            if (xi < 0 || size_t(xi) >= m_scanline.size()) {
+            if (xi < 0 || size_t(xi) >= m_scanline.size()) [[unlikely]] {
                 // FIXME: For very low dxdy values, floating point error can push the sample outside the scanline.
                 // This does not seem to make a visible difference most of the time (and is more likely from generated
                 // paths, such as this 3D canvas demo: https://www.kevs3d.co.uk/dev/html5logo/).
@@ -241,7 +241,7 @@ Color EdgeFlagPathRasterizer<SamplesPerPixel>::scanline_color(int scanline, int
 }
 
 template<unsigned SamplesPerPixel>
-Detail::Edge* EdgeFlagPathRasterizer<SamplesPerPixel>::plot_edges_for_scanline(int scanline, auto plot_edge, EdgeExtent& edge_extent, Detail::Edge* active_edges)
+__attribute__((hot)) Detail::Edge* EdgeFlagPathRasterizer<SamplesPerPixel>::plot_edges_for_scanline(int scanline, auto plot_edge, EdgeExtent& edge_extent, Detail::Edge* active_edges)
 {
     auto y_subpixel = [](int y) {
         return y & (SamplesPerPixel - 1);
@@ -368,7 +368,7 @@ void EdgeFlagPathRasterizer<SamplesPerPixel>::fast_fill_solid_color_span(ARGB32*
 
 template<unsigned SamplesPerPixel>
 template<Painter::WindingRule WindingRule>
-void EdgeFlagPathRasterizer<SamplesPerPixel>::write_scanline(Painter& painter, int scanline, EdgeExtent edge_extent, auto& color_or_function)
+FLATTEN __attribute__((hot)) void EdgeFlagPathRasterizer<SamplesPerPixel>::write_scanline(Painter& painter, int scanline, EdgeExtent edge_extent, auto& color_or_function)
 {
     // Handle scanline clipping.
     auto left_clip = m_clip.left() - m_blit_origin.x();
diff --git a/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.h b/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.h
index f0c9bc75ad..803323af01 100644
--- a/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.h
+++ b/Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.h
@@ -176,7 +176,7 @@ private:
     Detail::Edge* plot_edges_for_scanline(int scanline, auto plot_edge, EdgeExtent&, Detail::Edge* active_edges = nullptr);
 
     template<Painter::WindingRule>
-    void write_scanline(Painter&, int scanline, EdgeExtent, auto& color_or_function);
+    FLATTEN void write_scanline(Painter&, int scanline, EdgeExtent, auto& color_or_function);
     Color scanline_color(int scanline, int offset, u8 alpha, auto& color_or_function);
     void write_pixel(BitmapFormat format, ARGB32* scanline_ptr, int scanline, int offset, SampleType sample, auto& color_or_function);
     void fast_fill_solid_color_span(ARGB32* scanline_ptr, int start, int end, Color color);