Memory optimization stuff

Simulator/Actions/ActionType.cs

@@ -47,7 +47,7 @@ public enum ActionType : byte
 
 public static class ActionUtils
 {
-    private static readonly BaseAction[] Actions;
+    private static ReadOnlyMemory<BaseAction> Actions { get; }
 
     static ActionUtils()
     {
@@ -61,7 +61,7 @@ static ActionUtils()
 
     [Pure]
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static BaseAction Base(this ActionType me) => Actions[(int)me];
+    public static BaseAction Base(this ActionType me) => Actions.Span[(int)me];
 
     public static IEnumerable<ActionType> AvailableActions(Simulator simulation) =>
         simulation.IsComplete

Simulator/SimulationState.cs

@@ -18,7 +18,7 @@ public record struct SimulationState
     public ActionStates ActionStates;
 
     // https://github.com/ffxiv-teamcraft/simulator/blob/0682dfa76043ff4ccb38832c184d046ceaff0733/src/model/tables.ts#L2
-    private static readonly int[] HQPercentTable = {
+    private static ReadOnlySpan<int> HQPercentTable => new[] {
         1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8,
         9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 17, 17,
         17, 18, 18, 18, 19, 19, 20, 20, 21, 22, 23, 24, 26, 28, 31, 34, 38, 42, 47, 52, 58, 64, 68, 71,
@@ -44,13 +44,4 @@ public SimulationState(SimulationInput input)
         ActionCount = 0;
         ActionStates = new();
     }
-
-#if IS_DETERMINISTIC
-    public override readonly string ToString()
-    {
-        var b = new System.Text.StringBuilder();
-        PrintMembers(b);
-        return Convert.ToHexString(System.Security.Cryptography.SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(b.ToString())));
-    }
-#endif
 }

Solver/MCTS.cs

@@ -72,8 +72,8 @@ private static (int arrayIdx, int subIdx) ChildMaxScore(in NodeScoresBuffer scor
         {
             var iterCount = Math.Min(vecLength, length);
 
-            ref var chunk = ref scores.Data[i];
-            var m = new Vector<float>(chunk.MaxScore.Span);
+            ref var chunk = ref scores.Data!.Value.Span[i];
+            var m = new Vector<float>(chunk.MaxScore);
 
             var idx = Intrinsics.HMaxIndex(m, iterCount);
 
@@ -127,10 +127,10 @@ private static (int arrayIdx, int subIdx) EvalBestChild(
         {
             var iterCount = Math.Min(vecLength, length);
 
-            ref var chunk = ref scores.Data[i];
-            var s = new Vector<float>(chunk.ScoreSum.Span);
-            var vInt = new Vector<int>(chunk.Visits.Span);
-            var m = new Vector<float>(chunk.MaxScore.Span);
+            ref var chunk = ref scores.Data!.Value.Span[i];
+            var s = new Vector<float>(chunk.ScoreSum);
+            var vInt = new Vector<int>(chunk.Visits);
+            var m = new Vector<float>(chunk.MaxScore);
 
             vInt = Vector.Max(vInt, Vector<int>.One);
             var v = Vector.ConvertToSingle(vInt);

Solver/NodeScoresBuffer.cs

@@ -1,24 +1,26 @@
 using System.Diagnostics.Contracts;
 using System.Numerics;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 
 namespace Craftimizer.Solver;
 
 // Adapted from https://github.com/dtao/ConcurrentList/blob/4fcf1c76e93021a41af5abb2d61a63caeba2adad/ConcurrentList/ConcurrentList.cs
 public struct NodeScoresBuffer
 {
-    public sealed class ScoresBatch
+    public readonly struct ScoresBatch
     {
-        public Memory<float> ScoreSum;
-        public Memory<float> MaxScore;
-        public Memory<int> Visits;
-
-        public ScoresBatch()
-        {
-            ScoreSum = new float[BatchSize];
-            MaxScore = new float[BatchSize];
-            Visits = new int[BatchSize];
-        }
+        private readonly Memory<byte> data;
+
+        public Span<float> ScoreSum =>
+            MemoryMarshal.Cast<byte, float>(data.Span.Slice(0, BatchSize * sizeof(float)));
+        public Span<float> MaxScore =>
+            MemoryMarshal.Cast<byte, float>(data.Span.Slice(BatchSize * sizeof(float), BatchSize * sizeof(float)));
+        public Span<int> Visits =>
+            MemoryMarshal.Cast<byte, int>(data.Span.Slice(BatchSize * sizeof(float) * 2, BatchSize * sizeof(int)));
+
+        public ScoresBatch() =>
+            data = new byte[BatchSize * sizeof(float) * 3];
     }
 
     // Technically 25, but it's very unlikely to actually get to there.
@@ -31,7 +33,7 @@ public ScoresBatch()
 
     private static readonly int BatchCount = MaxSize / BatchSize;
 
-    public ScoresBatch[] Data;
+    public Memory<ScoresBatch>? Data;
     public int Count { get; private set; }
 
     public void Add()
@@ -40,20 +42,22 @@ public void Add()
 
         var idx = Count++;
 
-        var (arrayIdx, _) = GetArrayIndex(idx);
+        var (arrayIdx, subIdx) = GetArrayIndex(idx);
 
-        Data[arrayIdx] ??= new();
+        if (subIdx == 0)
+            Data.Value.Span[arrayIdx] = new();
     }
 
     public readonly void Visit((int arrayIdx, int subIdx) at, float score)
     {
-        Data[at.arrayIdx].ScoreSum.Span[at.subIdx] += score;
-        Data[at.arrayIdx].MaxScore.Span[at.subIdx] = Math.Max(Data[at.arrayIdx].MaxScore.Span[at.subIdx], score);
-        Data[at.arrayIdx].Visits.Span[at.subIdx]++;
+        ref var batch = ref Data!.Value.Span[at.arrayIdx];
+        batch.ScoreSum[at.subIdx] += score;
+        batch.MaxScore[at.subIdx] = Math.Max(batch.MaxScore[at.subIdx], score);
+        batch.Visits[at.subIdx]++;
     }
 
     public readonly int GetVisits((int arrayIdx, int subIdx) at) =>
-        Data[at.arrayIdx].Visits.Span[at.subIdx];
+        Data!.Value.Span[at.arrayIdx].Visits[at.subIdx];
 
     [Pure]
     [MethodImpl(MethodImplOptions.AggressiveInlining)]