Clear excessive branching and excess copying

BlueQuartzSoftware · Jul 18, 2024 · 06ac6f2 · 06ac6f2
1 parent 54484d4
commit 06ac6f2
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Showing 2 changed files with 63 additions and 139 deletions.
diff --git a/src/simplnx/Utilities/Math/GeometryMath.cpp b/src/simplnx/Utilities/Math/GeometryMath.cpp
@@ -54,121 +54,54 @@ BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfVertices(INodeGeometry0D
   return {ll, ur}; // should be valid
 }
 
-BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfFace(const TriangleGeom& faces, int32 faceId)
+BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfFace(const detail::GeometryStoreCache& cache, const nx::core::TriangleGeom& triangleGeom, int32 faceId)
 {
-  std::array<Point3Df, 3> points = {};
-  faces.getFaceCoordinates(faceId, points);
+  std::array<Point3Df, 3> points = GeometryMath::detail::GetFaceCoordinates<float32>(cache, faceId);
 
   Point3Df ll = points[0];
   Point3Df ur = points[0];
 
-  if(points[1][0] < ll[0])
-  {
-    ll[0] = points[1][0];
-  }
-  if(points[1][0] > ur[0])
-  {
-    ur[0] = points[1][0];
-  }
-  if(points[1][1] < ll[1])
-  {
-    ll[1] = points[1][1];
-  }
-  if(points[1][1] > ur[1])
-  {
-    ur[1] = points[1][1];
-  }
-  if(points[1][2] < ll[2])
-  {
-    ll[2] = points[1][2];
-  }
-  if(points[1][2] > ur[2])
-  {
-    ur[2] = points[1][2];
-  }
-  if(points[2][0] < ll[0])
-  {
-    ll[0] = points[2][0];
-  }
-  if(points[2][0] > ur[0])
-  {
-    ur[0] = points[2][0];
-  }
-  if(points[2][1] < ll[1])
-  {
-    ll[1] = points[2][1];
-  }
-  if(points[2][1] > ur[1])
-  {
-    ur[1] = points[2][1];
-  }
-  if(points[2][2] < ll[2])
-  {
-    ll[2] = points[2][2];
-  }
-  if(points[2][2] > ur[2])
-  {
-    ur[2] = points[2][2];
-  }
+  // Avoid Branch Prediction misses by exclusively doing multiplication operations
+  // C++ (§4.5/4):
+  // An r-value of type bool can be converted to an r-value of type int,
+  // with false becoming zero and true becoming one.
+  //
+  // The standard guarantees the same for float
+  bool swap = points[1][0] < ll[0];
+  ll[0] = points[1][0] * static_cast<float32>(swap) + ll[0] * static_cast<float32>(!swap);
 
-  return {ll, ur};
-}
+  swap = points[1][1] < ll[1];
+  ll[1] = points[1][1] * static_cast<float32>(swap) + ll[1] * static_cast<float32>(!swap);
 
-BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfFace(const detail::GeometryStoreCache& cache, const nx::core::TriangleGeom& triangleGeom, int32 faceId)
-{
-  std::array<Point3Df, 3> points = GeometryMath::detail::GetFaceCoordinates<float32>(cache, faceId);
+  swap = points[1][2] < ll[2];
+  ll[2] = points[1][2] * static_cast<float32>(swap) + ll[2] * static_cast<float32>(!swap);
 
-  Point3Df ll = points[0];
-  Point3Df ur = points[0];
+  swap = points[2][0] < ll[0];
+  ll[0] = points[2][0] * static_cast<float32>(swap) + ll[0] * static_cast<float32>(!swap);
 
-  if(points[1][0] < ll[0])
-  {
-    ll[0] = points[1][0];
-  }
-  if(points[1][0] > ur[0])
-  {
-    ur[0] = points[1][0];
-  }
-  if(points[1][1] < ll[1])
-  {
-    ll[1] = points[1][1];
-  }
-  if(points[1][1] > ur[1])
-  {
-    ur[1] = points[1][1];
-  }
-  if(points[1][2] < ll[2])
-  {
-    ll[2] = points[1][2];
-  }
-  if(points[1][2] > ur[2])
-  {
-    ur[2] = points[1][2];
-  }
-  if(points[2][0] < ll[0])
-  {
-    ll[0] = points[2][0];
-  }
-  if(points[2][0] > ur[0])
-  {
-    ur[0] = points[2][0];
-  }
-  if(points[2][1] < ll[1])
-  {
-    ll[1] = points[2][1];
-  }
-  if(points[2][1] > ur[1])
-  {
-    ur[1] = points[2][1];
-  }
-  if(points[2][2] < ll[2])
-  {
-    ll[2] = points[2][2];
-  }
-  if(points[2][2] > ur[2])
-  {
-    ur[2] = points[2][2];
-  }
+  swap = points[2][1] < ll[1];
+  ll[1] = points[2][1] * static_cast<float32>(swap) + ll[1] * static_cast<float32>(!swap);
+
+  swap = points[2][2] < ll[2];
+  ll[2] = points[2][2] * static_cast<float32>(swap) + ll[2] * static_cast<float32>(!swap);
+
+  swap = points[1][0] > ur[0];
+  ur[0] = points[1][0] * static_cast<float32>(swap) + ur[0] * static_cast<float32>(!swap);
+
+  swap = points[1][1] > ur[1];
+  ur[1] = points[1][1] * static_cast<float32>(swap) + ur[1] * static_cast<float32>(!swap);
+
+  swap = points[1][2] > ur[2];
+  ur[2] = points[1][2] * static_cast<float32>(swap) + ur[2] * static_cast<float32>(!swap);
+
+  swap = points[2][0] > ur[0];
+  ur[0] = points[2][0] * static_cast<float32>(swap) + ur[0] * static_cast<float32>(!swap);
+
+  swap = points[2][1] > ur[1];
+  ur[1] = points[2][1] * static_cast<float32>(swap) + ur[1] * static_cast<float32>(!swap);
+
+  swap = points[2][2] > ur[2];
+  ur[2] = points[2][2] * static_cast<float32>(swap) + ur[2] * static_cast<float32>(!swap);
 
   return {ll, ur};
 }
@@ -191,30 +124,29 @@ BoundingBox3Df nx::core::GeometryMath::FindBoundingBoxOfFaces(const nx::core::Tr
     Point3Df min = bounds.getMinPoint();
     Point3Df max = bounds.getMaxPoint();
 
-    if(min[0] < ll[0])
-    {
-      ll[0] = min[0];
-    }
-    if(min[1] < ll[1])
-    {
-      ll[1] = min[1];
-    }
-    if(min[2] < ll[2])
-    {
-      ll[2] = min[2];
-    }
-    if(max[0] > ur[0])
-    {
-      ur[0] = max[0];
-    }
-    if(max[1] > ur[1])
-    {
-      ur[1] = max[1];
-    }
-    if(max[2] > ur[2])
-    {
-      ur[2] = max[2];
-    }
+    // Avoid Branch Prediction misses by exclusively doing multiplication operations
+    // C++ (§4.5/4):
+    // An r-value of type bool can be converted to an r-value of type int,
+    // with false becoming zero and true becoming one.
+    //
+    // The standard guarantees the same for float
+    bool swap = min[0] < ll[0];
+    ll[0] = min[0] * static_cast<float32>(swap) + ll[0] * static_cast<float32>(!swap);
+
+    swap = min[1] < ll[1];
+    ll[1] = min[1] * static_cast<float32>(swap) + ll[1] * static_cast<float32>(!swap);
+
+    swap = min[2] < ll[2];
+    ll[2] = min[2] * static_cast<float32>(swap) + ll[2] * static_cast<float32>(!swap);
+
+    swap = max[0] > ur[0];
+    ur[0] = min[0] * static_cast<float32>(swap) + ur[0] * static_cast<float32>(!swap);
+
+    swap = max[1] > ur[1];
+    ur[1] = min[1] * static_cast<float32>(swap) + ur[1] * static_cast<float32>(!swap);
+
+    swap = max[2] > ur[2];
+    ur[2] = min[2] * static_cast<float32>(swap) + ur[2] * static_cast<float32>(!swap);
   }
 
   return {ll, ur};

diff --git a/src/simplnx/Utilities/Math/GeometryMath.hpp b/src/simplnx/Utilities/Math/GeometryMath.hpp
@@ -256,7 +256,7 @@ inline bool IsPointInBox(const nx::core::Point3D<T>& point, const nx::core::Boun
  * @return bool
  */
 template <typename T>
-bool DoesRayIntersectBox(nx::core::Ray<T> ray, const nx::core::BoundingBox3D<T>& bounds)
+bool DoesRayIntersectBox(const nx::core::Ray<T>& ray, const nx::core::BoundingBox3D<T>& bounds)
 {
   auto origin = ray.getOrigin();
   auto end = ray.getEndPoint();
@@ -395,14 +395,6 @@ nx::core::BoundingBox3Df SIMPLNX_EXPORT FindBoundingBoxOfVertices(nx::core::INod
  */
 nx::core::BoundingBox3Df SIMPLNX_EXPORT FindBoundingBoxOfRotatedFace(nx::core::TriangleGeom& faces, int32 faceId, float32 g[3][3]);
 
-/**
- * @brief Returns the BoundingBox around the specified face.
- * @param faces
- * @param faceId
- * @return nx::core::BoundingBox<float32>
- */
-nx::core::BoundingBox3Df FindBoundingBoxOfFace(const nx::core::TriangleGeom& faces, int32 faceId);
-
 /**
  * @brief Returns the BoundingBox around the specified face.
  * @param faces