some benchmarks and conceptual ideas

Author: thygrrr

fennecs.benchmarks/Conceptual/ForStructuralVsStateful.cs

@@ -0,0 +1,150 @@
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.X86;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Configs;
+using BenchmarkDotNet.Order;
+using fennecs;
+
+namespace Benchmark.Conceptual;
+
+[Orderer(SummaryOrderPolicy.FastestToSlowest)]
+[GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByParams)]
+public class ForStructuralVsStateful
+{
+    [Params(10_000)]
+    public int Entities { get; set; }
+    
+    [Params(0.9f, 0.5f, 0.1f)]
+    public float Homogenity { get; set; }
+    
+    [Params(100, 1_000, 10_000)]
+    public int Actions { get; set; }
+    
+    private World _world = null!;
+    private Stream<ushort> _stream = null!;
+    private Random _random = null!;
+
+    [GlobalSetup]
+    public void GlobaSetup()
+    {
+        _world = new(Entities * 30);
+
+        _stream = _world.Query<ushort>().Stream();
+        
+        _world.Spawn().Add(1).Despawn();
+    }
+    
+    [IterationSetup]
+    public void IterationSetup()
+    {
+        Console.WriteLine("IterationSetup");
+        _world.All.Despawn();
+        if (_world.Count != 0) throw new("World is not empty!");
+        
+        _random = new(69);
+        
+        _world.Entity().Spawn(Entities);
+        foreach (var entity in _world.All.ToArray())
+        {
+            entity.Add((ushort) _random.Next((ushort) (Actions * Homogenity), Actions));
+        }
+    }
+
+    [Benchmark]
+    public int CountDown_with_Structural_Change()
+    {
+        while (_stream.Count > 0)
+        {
+            _stream.For((in Entity entity, ref ushort value) =>
+            {
+                value--;
+                if (value <= 0) entity.Remove<ushort>();
+            });
+        }
+        return _stream.Count;
+    }
+
+    [Benchmark]
+    public int CountDown_with_Delayed_Change()
+    {
+        var done = false;
+        while (!done)
+        {
+            done = true;
+            _stream.For((ref ushort value) =>
+            {
+                if (value <= 0) return;
+                value--;
+                done = false; 
+            });
+        }
+        _stream.Query.Remove<ushort>();
+        return _stream.Count;
+    }
+
+    private record Done(bool done)
+    {
+        public bool done { get; set; } = done;
+    };
+
+    [Benchmark]
+    public int CountDown_with_Raw_Loop()
+    {
+        var done = new Done(false);
+
+        while (!done.done)
+        {
+            _stream.Raw(values =>
+                {
+                    var localDone = true;
+                    var span = values.Span;
+                    for (var i = 0; i < span.Length; i++)
+                    {
+                        if (span[i] <= 0) continue;
+                        localDone = false;
+                        span[i]--;
+                    }
+                    done.done = localDone;
+                }
+            );
+        }
+        _stream.Query.Remove<ushort>();
+        return _stream.Count;
+    }
+
+    [Benchmark]
+    public int CountDown_with_Raw_SIMD()
+    {
+        var done = new Done(false);
+
+        while (!done.done)
+        {
+            _stream.Raw(values =>
+            {
+                var count = values.Length;
+                var localDone = true;
+                
+                using var mem1 = values.Pin();
+
+                unsafe
+                {
+                    var p1 = (ushort*)mem1.Pointer;
+
+                    var vectorSize = Vector256<ushort>.Count;
+                    var vectorEnd = count - count % vectorSize;
+                    for (var i = 0; i <= vectorEnd; i += vectorSize)
+                    {
+                        var v1 = Avx.LoadVector256(p1 + i);
+                        var sum = Avx2.SubtractSaturate(v1, Vector256<ushort>.One);
+                        Avx.Store(p1 + i, sum);
+                        localDone &= sum == Vector256<ushort>.Zero;
+                    }
+                }
+                done.done = localDone;
+            }
+            );
+        }
+        _stream.Query.Remove<ushort>();
+        return _stream.Count;
+    }
+}

fennecs.benchmarks/Conceptual/CostCentersBench.cs renamed to fennecs.benchmarks/Conceptual/QueryWideVsTall.cs

@@ -3,7 +3,7 @@
 
 namespace Benchmark.Conceptual;
 
-public class CostCentersBench
+public class QueryWideVsTall
 {
     [Params(10000)]
     public int Count { get; set; }

fennecs.benchmarks/Program.cs

@@ -1,6 +1,7 @@
 using System.Runtime.Intrinsics.Arm;
 using System.Runtime.Intrinsics.X86;
 using Benchmark;
+using Benchmark.Conceptual;
 using Benchmark.ECS;
 using BenchmarkDotNet.Configs;
 using BenchmarkDotNet.Environments;
@@ -14,8 +15,8 @@
     .HideColumns("Job", "Error", "Median", "RatioSD");
 
 var jobs = new List<Job>([
-    Job.ShortRun.WithId("Default").WithRuntime(CoreRuntime.Core90),
-    Job.ShortRun.WithId("Native").WithRuntime(NativeAotRuntime.Net90),
+    Job.MediumRun.WithId("Default").WithRuntime(CoreRuntime.Core90), 
+    //Job.ShortRun.WithId("Native").WithRuntime(NativeAotRuntime.Net90),
 ]);
 
 
@@ -31,4 +32,4 @@
 if (!AdvSimd.IsSupported) config.AddFilter(new CategoryExclusion(nameof(AdvSimd)));
 
 
-BenchmarkRunner.Run<DorakuBenchmarks>(config);
+BenchmarkRunner.Run<ForStructuralVsStateful>(config);