JonKazama-Hellion/Craftimizer
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Fancy simd horizontal max

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This commit is contained in:
Asriel Camora
2023-06-21 16:12:44 -07:00
parent 5faaa02f1a
commit dba76e319c
1 changed files with 51 additions and 20 deletions
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Solver/Crafty/Solver.cs
+50 -19
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@@ -1,9 +1,13 @@
using Craftimizer.Simulator;
using Craftimizer.Simulator.Actions;
using System;
using System.Diagnostics;
using System.Diagnostics.Contracts;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;
using Node = Craftimizer.Solver.Crafty.ArenaNode<Craftimizer.Solver.Crafty.SimulationNode>;
namespace Craftimizer.Solver.Crafty;
@@ -79,38 +83,63 @@ public class Solver
return source[max];
}
[Pure]
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static Vector<float> EvalBestChildVectorized(float w, float W, Vector<float> C, Vector<float> scoreSums, Vector<float> visits, Vector<float> maxScores)
// https://stackoverflow.com/a/73439472
private static Vector128<float> HMax(Vector256<float> v1)
{
var exploitation = W * (scoreSums / visits) + w * maxScores;
var exploration = Vector.SquareRoot(C / visits);
return exploitation + exploration;
var v2 = Avx.Permute(v1, 0b10110001);
var v3 = Avx.Max(v1, v2);
var v4 = Avx.Permute(v3, 0b00001010);
var v5 = Avx.Max(v3, v4);
var v6 = Avx.ExtractVector128(v5, 1);
var v7 = Sse.Max(v5.GetLower(), v6);
return v7;
}
private static int AlignToVectorLength(int length) =>
(length + (Vector<float>.Count - 1)) & ~(Vector<float>.Count - 1);
[Pure]
[MethodImpl(MethodImplOptions.AggressiveInlining)]
// https://stackoverflow.com/a/23592221
private static (int, uint) HMaxIndex(Vector256<float> v, int len)
{
var vfilt = Avx.Blend(v, Vector256<float>.Zero, (byte)~((1 << len) - 1));
var vmax128 = HMax(vfilt);
var vmax = Vector256.Create(vmax128, vmax128);
var vcmp = Avx.CompareEqual(v, vmax);
var mask = unchecked((uint)Avx2.MoveMask(vcmp.AsByte()));
mask <<= (8 - len) << 2;
var inverseIdx = BitOperations.LeadingZeroCount(mask) >> 2;
return (len - 1 - inverseIdx, mask);
}
[Pure]
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private Node EvalBestChild(float parentVisits, ReadOnlySpan<Node> children)
{
var length = children.Length;
var vecLength = Vector<float>.Count;
var C = Config.ExplorationConstant * MathF.Log(parentVisits);
var w = Config.MaxScoreWeightingConstant;
var W = 1f - w;
var CVector = new Vector<float>(C);
Span<float> scoreSums = stackalloc float[Vector<float>.Count];
Span<float> visits = stackalloc float[Vector<float>.Count];
Span<float> maxScores = stackalloc float[Vector<float>.Count];
Span<float> scoreSums = stackalloc float[vecLength];
Span<float> visits = stackalloc float[vecLength];
Span<float> maxScores = stackalloc float[vecLength];
var max = 0;
var maxScore = 0f;
for (var i = 0; i < length; i += Vector<float>.Count)
for (var i = 0; i < length; i += vecLength)
{
var iterCount = i + Vector<float>.Count > length ?
var iterCount = i + vecLength > length ?
length - i :
Vector<float>.Count;
vecLength;
for (var j = 0; j < iterCount; ++j)
{
@@ -119,15 +148,17 @@ public class Solver
visits[j] = node.Visits;
maxScores[j] = node.MaxScore;
}
var evalScores = EvalBestChildVectorized(w, W, CVector, new(scoreSums), new(visits), new(maxScores));
for (var j = 0; j < iterCount; ++j)
var exploitation = (W * (new Vector<float>(scoreSums) / new Vector<float>(visits))) + (w * new Vector<float>(maxScores));
var exploration = Vector.SquareRoot(CVector / new Vector<float>(visits));
var evalScores = exploitation + exploration;
var (idx, mask) = HMaxIndex(evalScores.AsVector256(), iterCount);
if (evalScores[idx] >= maxScore)
{
if (evalScores[j] >= maxScore)
{
max = i + j;
maxScore = evalScores[j];
}
max = i + idx;
maxScore = evalScores[idx];
}
}