Benchmarked performance when flipping bytes for endianness.

Benchmarks/EndiannessComparison.cs

@@ -0,0 +1,89 @@
+using System;
+using System.IO;
+using System.Runtime.CompilerServices;
+
+using BenchmarkDotNet.Attributes;
+
+using CommunityToolkit.HighPerformance;
+
+using schema.binary;
+
+
+namespace benchmarks;
+
+[MemoryDiagnoser]
+public class EndiannessComparison {
+  public const int n = 10000;
+
+  [Params(Endianness.BigEndian, Endianness.LittleEndian)]
+  public Endianness Endianness { get; set; }
+
+  public uint[] values_ = new uint[n];
+
+  [Benchmark]
+  public void ReverseSpansManually() {
+    var span = this.values_.AsSpan().AsBytes();
+    for (var i = 0; i < span.Length; i++) {
+      span.Slice(4 * i, 4).Reverse();
+    }
+  }
+
+  [Benchmark]
+  public void ReverseSpansUsingReverser() {
+    var reverser = new SpanElementReverser();
+
+    var span = this.values_.AsSpan().AsBytes();
+    reverser.ReverseElements(span, 4);
+  }
+
+  [Benchmark]
+  public void ReverseSpansUsingReverserInterface() {
+    ISpanElementReverser reverser = new SpanElementReverser();
+
+    var span = this.values_.AsSpan().AsBytes();
+    reverser.ReverseElements(span, 4);
+  }
+
+  [Benchmark]
+  public void ReverseSpansUsingReverserNoop() {
+    var reverser = new NoopSpanElementReverser();
+
+    var span = this.values_.AsSpan().AsBytes();
+    reverser.ReverseElements(span, 4);
+  }
+
+  [Benchmark]
+  public void ReverseSpansUsingReverserNoopInterface() {
+    ISpanElementReverser reverser = new NoopSpanElementReverser();
+
+    var span = this.values_.AsSpan().AsBytes();
+    reverser.ReverseElements(span, 4);
+  }
+
+  [Benchmark]
+  public void ReverseSpansAsUintsInlined() {
+    var span = this.values_.AsSpan();
+    for (var i = 0; i < span.Length; i++) {
+      var value = span[i];
+      span[i] = (value & 0x000000FFU) << 24 |
+                (value & 0x0000FF00U) << 8 |
+                (value & 0x00FF0000U) >> 8 |
+                (value & 0xFF000000U) >> 24;
+    }
+  }
+
+  [Benchmark]
+  public void ReverseSpansAsUintsViaMethod() {
+    var span = this.values_.AsSpan();
+    for (var i = 0; i < span.Length; i++) {
+      span[i] = ReverseBytes(span[i]);
+    }
+  }
+
+
+  [MethodImpl(MethodImplOptions.AggressiveInlining)]
+  public static uint ReverseBytes(uint value) {
+    return (value & 0x000000FFU) << 24 | (value & 0x0000FF00U) << 8 |
+           (value & 0x00FF0000U) >> 8 | (value & 0xFF000000U) >> 24;
+  }
+}

Benchmarks/Main.cs

@@ -7,7 +7,7 @@ namespace benchmarks;
 
 public class Program {
   public static void Main(string[] args) {
-    var summary = BenchmarkRunner.Run<ReadingValues>(
+    var summary = BenchmarkRunner.Run<EndiannessComparison>(
         ManualConfig
             .Create(DefaultConfig.Instance)
             .AddDiagnoser(