Cycles: OpenCL Performance

When using OpenCL with Cycles the rendering time increased substantial.
After doing some tests the bottleneck was found in 4d voronoi and 2d and
3d smooth voronoi.

This change will hide these behind a specific compile directive so the
speed will improve.

AMD RX480 + BMW scene

    2.80 (3:10)
    2.81 (5:48)
    2.81 excluding 4d voronoi+2d/3d smooth (3:50)

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D6231

1 files changed, 12 insertions, 0 deletions

diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 13e9b65fa07..62037b0d381 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -220,6 +220,18 @@ class VoronoiTextureNode : public TextureNode {
     return NODE_GROUP_LEVEL_2;
   }
 
+  virtual int get_feature()
+  {
+    int result = ShaderNode::get_feature();
+    if (dimensions == 4) {
+      result |= NODE_FEATURE_VORONOI_EXTRA;
+    }
+    else if (dimensions >= 2 && feature == NODE_VORONOI_SMOOTH_F1) {
+      result |= NODE_FEATURE_VORONOI_EXTRA;
+    }
+    return result;
+  }
+
   int dimensions;
   NodeVoronoiDistanceMetric metric;
   NodeVoronoiFeature feature;