CyclicBuffers SIMD

src/DotRecast.Core/Buffers/RcCyclicBuffer.cs

@@ -262,6 +262,11 @@ namespace DotRecast.Core.Buffers
             return new Span<T>(_buffer, 0, _end);
         }
 
+        internal ReadOnlySpan<T> GetBufferSpan()
+        {
+            return _buffer;
+        }
+
         public Enumerator GetEnumerator() => new Enumerator(this);
         
         IEnumerator<T> IEnumerable<T>.GetEnumerator() => GetEnumerator();

src/DotRecast.Core/Buffers/RcCyclicBuffers.cs

@@ -1,20 +1,31 @@
-namespace DotRecast.Core.Buffers
+using System;
+using System.Numerics;
+using System.Runtime.InteropServices;
+
+namespace DotRecast.Core.Buffers
 {
     public static class RcCyclicBuffers
     {
         public static long Sum(this RcCyclicBuffer<long> source)
         {
-            long sum = 0;
+            var buffer = source.GetBufferSpan();
-            checked
+            var result = 0L;
+            if (Vector.IsHardwareAccelerated)
             {
-                // NOTE: SIMD would be nice here
+                var vectors = MemoryMarshal.Cast<long, Vector<long>>(buffer);
-                foreach (var x in source)
+                var vecSum = Vector<long>.Zero;
-                {
+                foreach (var vec in vectors)
-                    sum += x;
+                    vecSum += vec;
-                }
-            }
 
-            return sum;
+                result = Vector.Dot(vecSum, Vector<long>.One);
+                var remainder = source.Size % Vector<long>.Count;
+                buffer = buffer[^remainder..];
+            }
+            
+            foreach (var val in buffer)
+                result += val;
+            
+            return result;
         }
 
         public static double Average(this RcCyclicBuffer<long> source)
@@ -27,32 +38,54 @@
         
         public static long Min(this RcCyclicBuffer<long> source)
         {
-            if (0 >= source.Size)
+            var buffer = source.GetBufferSpan();
-                return 0;
+            var result = long.MaxValue;
             
-            long minValue = long.MaxValue;
+            if (Vector.IsHardwareAccelerated)
-            foreach (var x in source)
             {
-                if (x < minValue)
+                var vectors = MemoryMarshal.Cast<long, Vector<long>>(buffer);
-                    minValue = x;
+                var vecMin = Vector<long>.One * result;
-            }
+                
+                foreach (var vec in vectors)
+                    vecMin = Vector.Min(vecMin, vec);
 
-            return minValue;
+                for (int i = 0; i < Vector<long>.Count; i++)
+                    result = Math.Min(result, vecMin[i]);
+                
+                var remainder = source.Size % Vector<long>.Count;
+                buffer = buffer[^remainder..];
+            }
+            
+            foreach (var val in buffer)
+                result = Math.Min(result, val);
+
+            return result;
         }
         
         public static long Max(this RcCyclicBuffer<long> source)
         {
-            if (0 >= source.Size)
+            var buffer = source.GetBufferSpan();
-                return 0;
+            var result = long.MinValue;
             
-            long maxValue = long.MinValue;
+            if (Vector.IsHardwareAccelerated)
-            foreach (var x in source)
             {
-                if (x > maxValue)
+                var vectors = MemoryMarshal.Cast<long, Vector<long>>(buffer);
-                    maxValue = x;
+                var vecMax = Vector<long>.One * result;
-            }
+                
+                foreach (var vec in vectors)
+                    vecMax = Vector.Max(vecMax, vec);
 
-            return maxValue;
+                for (int i = 0; i < Vector<long>.Count; i++)
+                    result = Math.Max(result, vecMax[i]);
+                
+                var remainder = source.Size % Vector<long>.Count;
+                buffer = buffer[^remainder..];
+            }
+            
+            foreach (var val in buffer)
+                result = Math.Max(result, val);
+
+            return result;
         }
     }
 }

test/DotRecast.Core.Test/RcCyclicBufferTest.cs

@@ -330,4 +330,68 @@ public class RcCyclicBufferTests
             Assert.That(enumerator.Current, Is.EqualTo(refValues[index++]));
         }
     }
+    
+    [Test]
+    public void RcCyclicBuffers_Sum()
+    {
+        var refValues = Enumerable.Range(-100, 211).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Sum(buffer), Is.EqualTo(refValues.Sum()));
+    }
+    
+    [Test]
+    public void RcCyclicBuffers_Average()
+    {
+        var refValues = Enumerable.Range(-100, 211).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Average(buffer), Is.EqualTo(refValues.Average()));
+    }
+
+    [Test]
+    public void RcCyclicBuffers_Min()
+    {
+        var refValues = Enumerable.Range(-100, 211).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Min(buffer), Is.EqualTo(refValues.Min()));
+    }
+
+    [Test]
+    public void RcCyclicBuffers_Max()
+    {
+        var refValues = Enumerable.Range(-100, 211).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Max(buffer), Is.EqualTo(refValues.Max()));
+    }
+    
+    [Test]
+    public void RcCyclicBuffers_SumUnaligned()
+    {
+        var refValues = Enumerable.Range(-1, 3).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Sum(buffer), Is.EqualTo(refValues.Sum()));
+    }
+    
+    [Test]
+    public void RcCyclicBuffers_AverageUnaligned()
+    {
+        var refValues = Enumerable.Range(-1, 3).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Average(buffer), Is.EqualTo(refValues.Average()));
+    }
+
+    [Test]
+    public void RcCyclicBuffers_MinUnaligned()
+    {
+        var refValues = Enumerable.Range(5, 3).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Min(buffer), Is.EqualTo(refValues.Min()));
+    }
+
+    [Test]
+    public void RcCyclicBuffers_MaxUnaligned()
+    {
+        var refValues = Enumerable.Range(-5, 3).Select(x => (long)x).ToArray();
+        var buffer = new RcCyclicBuffer<long>(refValues.Length, refValues);
+        Assert.That(RcCyclicBuffers.Max(buffer), Is.EqualTo(refValues.Max()));
+    }
 }