mirror of
https://github.com/Stone-Red-Code/StoneRed.LogicSimulator.git
synced 2026-09-04 09:06:29 +02:00
689 lines
20 KiB
C#
689 lines
20 KiB
C#
using System;
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using System.Linq.Expressions;
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namespace StoneRed.LogicSimulator.Test;
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public enum GateKind : byte
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{
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Source,
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Not,
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And2,
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Or2,
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Buffer,
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Sink,
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Lut,
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}
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public sealed class ExprCircuitSimulator
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{
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private readonly List<GateKind> gateKinds = [];
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private readonly List<(int FromGate, int ToGate, byte ToInputBit)> connections = [];
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private readonly List<int[]?> lutTableByGate = [];
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private readonly Dictionary<string, MacroInfo> macroGates = new(StringComparer.Ordinal);
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private int[] inputMasks = Array.Empty<int>();
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private int[] nextInputMasks = Array.Empty<int>();
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private int[] outputMasks = Array.Empty<int>();
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private int[] sourceStates = Array.Empty<int>();
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private int[] edgeStart = Array.Empty<int>();
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private int[] edgeToGate = Array.Empty<int>();
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private byte[] edgeToInputBit = Array.Empty<byte>();
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private int[] lutOffsets = Array.Empty<int>();
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private int[] lutMasks = Array.Empty<int>();
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private int[] lutData = Array.Empty<int>();
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private Action<int[], int[], int[]>? computeOutputs;
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private bool compiled;
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private readonly List<GateWatcherEntry> gateWatchers = [];
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private int nextWatcherId;
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private sealed record GateWatcherEntry(int Id, int GateId, Action<int, int> Callback);
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public int GateCount => gateKinds.Count;
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public sealed record MacroInstance(string Name, int[] Inputs, int[] Outputs);
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private sealed record MacroLut(int InputCount, int OutputCount, int[][] OutputTables);
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private sealed record MacroInfo(CircuitDefinition Definition, MacroLut? Lut);
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public int AddGate(GateKind kind)
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{
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if (kind == GateKind.Lut)
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{
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throw new InvalidOperationException("Use AddLutGate() to create LUT gates.");
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}
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int id = gateKinds.Count;
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gateKinds.Add(kind);
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lutTableByGate.Add(null);
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compiled = false;
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return id;
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}
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public int AddLutGate(int inputCount, int[] table)
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{
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if (inputCount is < 0 or > 30)
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{
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throw new ArgumentOutOfRangeException(nameof(inputCount), "LUT input count must be between 0 and 30.");
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}
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if (table is null)
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{
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throw new ArgumentNullException(nameof(table));
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}
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int expected = 1 << inputCount;
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if (table.Length != expected)
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{
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throw new ArgumentException($"LUT table length must be {expected} for {inputCount} inputs.", nameof(table));
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}
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int id = gateKinds.Count;
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gateKinds.Add(GateKind.Lut);
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lutTableByGate.Add(table);
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compiled = false;
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return id;
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}
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public void ConnectGates(int fromGate, int toGate, int toInputBit)
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{
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if ((uint)fromGate >= (uint)gateKinds.Count)
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{
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throw new ArgumentOutOfRangeException(nameof(fromGate));
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}
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if ((uint)toGate >= (uint)gateKinds.Count)
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{
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throw new ArgumentOutOfRangeException(nameof(toGate));
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}
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if ((uint)toInputBit >= 32u)
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{
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throw new ArgumentOutOfRangeException(nameof(toInputBit));
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}
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connections.Add((fromGate, toGate, (byte)toInputBit));
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compiled = false;
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}
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public void RegisterMacroGate(string name, CircuitDefinition definition)
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{
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if (string.IsNullOrWhiteSpace(name))
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{
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throw new ArgumentException("Macro name must not be empty.", nameof(name));
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}
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definition.Validate();
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macroGates[name] = new MacroInfo(definition, Lut: null);
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compiled = false;
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}
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public bool ComputeLut(string name, int maxSteps = 4096)
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{
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if (string.IsNullOrWhiteSpace(name))
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{
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throw new ArgumentException("Macro name must not be empty.", nameof(name));
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}
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if (maxSteps <= 0)
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{
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throw new ArgumentOutOfRangeException(nameof(maxSteps));
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}
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if (!macroGates.TryGetValue(name, out MacroInfo? macro))
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{
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throw new KeyNotFoundException($"Macro gate '{name}' is not registered.");
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}
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MacroLut? lut = TryBuildMacroLut(macro.Definition, maxSteps: maxSteps);
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macroGates[name] = macro with { Lut = lut };
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compiled = false;
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return lut is not null;
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}
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public MacroInstance AddMacroGate(string name)
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{
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if (!macroGates.TryGetValue(name, out MacroInfo? macro))
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{
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throw new KeyNotFoundException($"Macro gate '{name}' is not registered.");
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}
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CircuitDefinition definition = macro.Definition;
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if (macro.Lut is not null)
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{
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return AddMacroGateFromLut(name, macro.Lut);
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}
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// Inline (flatten) definition into this simulator by copying its gates and connections.
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// Input pins are represented as Source gates in the definition, but Source gates cannot be driven by wires.
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// For each input pin we substitute a Buffer gate, which can be driven externally and fans out internally.
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int[] map = CopyDefinitionGatesAndConnections(
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destination: this,
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definition: definition,
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mapKind: (gateId, kind) =>
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kind == GateKind.Source
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? (definition.InputPins.Contains(gateId) ? GateKind.Buffer : throw new InvalidOperationException("Only Source gates marked as InputPins are allowed inside a macro definition."))
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: kind);
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int[] inputs = MapPins(definition.InputPins, map);
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int[] outputs = MapPins(definition.OutputPins, map);
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return new MacroInstance(name, inputs, outputs);
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}
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public void ClearSignals()
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{
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EnsureStorage();
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Array.Clear(inputMasks);
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Array.Clear(nextInputMasks);
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Array.Clear(outputMasks);
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}
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public void SetSource(int gateId, bool value)
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{
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EnsureStorage();
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if ((uint)gateId >= (uint)gateKinds.Count)
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{
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throw new ArgumentOutOfRangeException(nameof(gateId));
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}
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if (gateKinds[gateId] != GateKind.Source)
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{
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throw new InvalidOperationException("Gate is not a source.");
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}
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sourceStates[gateId] = value ? 1 : 0;
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}
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public bool GetOutput(int gateId)
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{
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EnsureStorage();
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if ((uint)gateId >= (uint)gateKinds.Count)
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{
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throw new ArgumentOutOfRangeException(nameof(gateId));
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}
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return (outputMasks[gateId] & 1) != 0;
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}
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public void Step()
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{
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EnsureCompiled();
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computeOutputs!(inputMasks, outputMasks, sourceStates);
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Propagate();
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NotifyWatchers();
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}
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public int RunUntilStable(int maxSteps = 1024)
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{
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if (!TryRunUntilStable(maxSteps, out int steps))
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{
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throw new InvalidOperationException($"Circuit did not stabilize within {maxSteps} steps.");
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}
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return steps;
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}
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private void Propagate()
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{
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Array.Clear(nextInputMasks);
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for (int fromGate = 0; fromGate < gateKinds.Count; fromGate++)
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{
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if ((outputMasks[fromGate] & 1) == 0)
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{
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continue;
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}
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int start = edgeStart[fromGate];
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int end = edgeStart[fromGate + 1];
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for (int e = start; e < end; e++)
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{
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int toGate = edgeToGate[e];
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nextInputMasks[toGate] |= 1 << edgeToInputBit[e];
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}
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}
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(inputMasks, nextInputMasks) = (nextInputMasks, inputMasks);
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}
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private bool PropagateAndSwapDetectChange()
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{
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Array.Clear(nextInputMasks);
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for (int fromGate = 0; fromGate < gateKinds.Count; fromGate++)
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{
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if ((outputMasks[fromGate] & 1) == 0)
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{
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continue;
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}
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int start = edgeStart[fromGate];
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int end = edgeStart[fromGate + 1];
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for (int e = start; e < end; e++)
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{
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int toGate = edgeToGate[e];
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nextInputMasks[toGate] |= 1 << edgeToInputBit[e];
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}
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}
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bool changed = false;
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for (int i = 0; i < inputMasks.Length; i++)
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{
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if (inputMasks[i] != nextInputMasks[i])
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{
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changed = true;
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break;
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}
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}
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(inputMasks, nextInputMasks) = (nextInputMasks, inputMasks);
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return changed;
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}
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private void EnsureStorage()
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{
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int n = gateKinds.Count;
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if (inputMasks.Length == n)
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{
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return;
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}
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inputMasks = new int[n];
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nextInputMasks = new int[n];
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outputMasks = new int[n];
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sourceStates = new int[n];
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}
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private void EnsureCompiled()
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{
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EnsureStorage();
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if (compiled)
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{
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return;
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}
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CompileNetlist();
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CompileLuts();
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computeOutputs = CompileComputeOutputsExpr();
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compiled = true;
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}
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private void CompileNetlist()
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{
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int n = gateKinds.Count;
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edgeStart = new int[n + 1];
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for (int i = 0; i < connections.Count; i++)
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{
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(int from, _, _) = connections[i];
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edgeStart[from + 1]++;
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}
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for (int i = 1; i < edgeStart.Length; i++)
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{
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edgeStart[i] += edgeStart[i - 1];
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}
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edgeToGate = new int[connections.Count];
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edgeToInputBit = new byte[connections.Count];
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int[] cursor = (int[])edgeStart.Clone();
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for (int i = 0; i < connections.Count; i++)
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{
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(int from, int to, byte bit) = connections[i];
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int at = cursor[from]++;
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edgeToGate[at] = to;
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edgeToInputBit[at] = bit;
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}
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}
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private void CompileLuts()
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{
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int n = gateKinds.Count;
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lutOffsets = new int[n];
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lutMasks = new int[n];
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int total = 0;
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for (int i = 0; i < n; i++)
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{
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if (gateKinds[i] != GateKind.Lut)
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{
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continue;
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}
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int[]? table = lutTableByGate[i];
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if (table is null)
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{
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throw new InvalidOperationException("LUT gate is missing its truth table.");
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}
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if (!IsPowerOfTwo(table.Length))
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{
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throw new InvalidOperationException("LUT table length must be a power of two.");
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}
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lutOffsets[i] = total;
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lutMasks[i] = table.Length - 1;
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total += table.Length;
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}
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lutData = new int[total];
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int cursor = 0;
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for (int i = 0; i < n; i++)
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{
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if (gateKinds[i] != GateKind.Lut)
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{
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continue;
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}
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int[] table = lutTableByGate[i]!;
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Array.Copy(table, 0, lutData, cursor, table.Length);
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cursor += table.Length;
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}
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}
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private Action<int[], int[], int[]> CompileComputeOutputsExpr()
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{
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ParameterExpression inputsParam = Expression.Parameter(typeof(int[]), "inputs");
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ParameterExpression outputsParam = Expression.Parameter(typeof(int[]), "outputs");
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ParameterExpression sourcesParam = Expression.Parameter(typeof(int[]), "sources");
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ConstantExpression lutDataConst = Expression.Constant(lutData);
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Expression[] block = new Expression[gateKinds.Count];
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for (int i = 0; i < gateKinds.Count; i++)
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{
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ConstantExpression idx = Expression.Constant(i);
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Expression inMask = Expression.ArrayIndex(inputsParam, idx);
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Expression outExpr = gateKinds[i] switch
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{
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GateKind.Source => Expression.And(Expression.ArrayIndex(sourcesParam, idx), Expression.Constant(1)),
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GateKind.Not => Expression.Condition(
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Expression.Equal(Expression.And(inMask, Expression.Constant(1)), Expression.Constant(0)),
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Expression.Constant(1),
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Expression.Constant(0)),
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GateKind.And2 => Expression.Condition(
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Expression.Equal(Expression.And(inMask, Expression.Constant(0b11)), Expression.Constant(0b11)),
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Expression.Constant(1),
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Expression.Constant(0)),
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GateKind.Or2 => Expression.Condition(
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Expression.NotEqual(Expression.And(inMask, Expression.Constant(0b11)), Expression.Constant(0)),
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Expression.Constant(1),
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Expression.Constant(0)),
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GateKind.Buffer => Expression.Condition(
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Expression.NotEqual(Expression.And(inMask, Expression.Constant(1)), Expression.Constant(0)),
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Expression.Constant(1),
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Expression.Constant(0)),
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GateKind.Sink => Expression.Condition(
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Expression.NotEqual(Expression.And(inMask, Expression.Constant(1)), Expression.Constant(0)),
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Expression.Constant(1),
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Expression.Constant(0)),
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GateKind.Lut => Expression.ArrayIndex(
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lutDataConst,
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Expression.Add(
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Expression.Constant(lutOffsets[i]),
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Expression.And(inMask, Expression.Constant(lutMasks[i])))),
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_ => throw new ArgumentOutOfRangeException(),
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};
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block[i] = Expression.Assign(Expression.ArrayAccess(outputsParam, idx), outExpr);
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}
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BlockExpression body = Expression.Block(block);
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return Expression.Lambda<Action<int[], int[], int[]>>(body, inputsParam, outputsParam, sourcesParam).Compile();
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}
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private static bool IsPowerOfTwo(int value) => value > 0 && (value & (value - 1)) == 0;
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private MacroLut? TryBuildMacroLut(CircuitDefinition definition, int maxSteps)
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{
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int inputCount = definition.InputPins.Count;
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int outputCount = definition.OutputPins.Count;
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if (inputCount < 0 || outputCount <= 0)
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{
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return null;
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}
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if (inputCount > 30)
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{
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throw new InvalidOperationException("Cannot build a LUT for macros with more than 30 inputs (would overflow 32-bit indexing).");
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}
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int patterns = 1 << inputCount;
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var sim = new ExprCircuitSimulator();
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foreach ((string macroName, MacroInfo macroInfo) in macroGates)
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{
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sim.macroGates[macroName] = macroInfo;
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}
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int[] map = CopyDefinitionGatesAndConnections(sim, definition, static (_, kind) => kind);
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int[] inGates = MapPins(definition.InputPins, map);
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int[] outGates = MapPins(definition.OutputPins, map);
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int[][] outputTables = new int[outputCount][];
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for (int o = 0; o < outputCount; o++)
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{
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outputTables[o] = new int[patterns];
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}
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for (int pattern = 0; pattern < patterns; pattern++)
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{
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sim.ClearSignals();
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for (int i = 0; i < inputCount; i++)
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{
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bool bit = ((pattern >> i) & 1) != 0;
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sim.SetSource(inGates[i], bit);
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}
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if (!sim.TryRunUntilStable(maxSteps: maxSteps, out _))
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{
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return null;
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}
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for (int o = 0; o < outputCount; o++)
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{
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outputTables[o][pattern] = sim.GetOutput(outGates[o]) ? 1 : 0;
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}
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}
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return new MacroLut(inputCount, outputCount, outputTables);
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}
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private MacroInstance AddMacroGateFromLut(string name, MacroLut lut)
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{
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int[] inputs = new int[lut.InputCount];
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for (int i = 0; i < inputs.Length; i++)
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{
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inputs[i] = AddGate(GateKind.Buffer);
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}
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int[] outputs = new int[lut.OutputCount];
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for (int o = 0; o < outputs.Length; o++)
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{
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int lutGate = AddLutGate(lut.InputCount, lut.OutputTables[o]);
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for (int i = 0; i < inputs.Length; i++)
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{
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ConnectGates(inputs[i], lutGate, toInputBit: i);
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}
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int sink = AddGate(GateKind.Sink);
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ConnectGates(lutGate, sink, toInputBit: 0);
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outputs[o] = sink;
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}
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return new MacroInstance(name, inputs, outputs);
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}
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public IDisposable WatchGate(int gateId, Action<int, int> callback)
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{
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if (callback is null)
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{
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throw new ArgumentNullException(nameof(callback));
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}
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if ((uint)gateId >= (uint)gateKinds.Count)
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{
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throw new ArgumentOutOfRangeException(nameof(gateId));
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}
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int id = nextWatcherId++;
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var entry = new GateWatcherEntry(id, gateId, callback);
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gateWatchers.Add(entry);
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return new GateWatcherSubscription(this, id);
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}
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private void RemoveWatcher(int id)
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{
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gateWatchers.RemoveAll(w => w.Id == id);
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}
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private void NotifyWatchers()
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{
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if (gateWatchers.Count == 0)
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{
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return;
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}
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GateWatcherEntry[] snapshot = gateWatchers.ToArray();
|
|
for (int i = 0; i < snapshot.Length; i++)
|
|
{
|
|
GateWatcherEntry entry = snapshot[i];
|
|
entry.Callback(entry.GateId, outputMasks[entry.GateId]);
|
|
}
|
|
}
|
|
|
|
private sealed class GateWatcherSubscription : IDisposable
|
|
{
|
|
private readonly ExprCircuitSimulator simulator;
|
|
private readonly int id;
|
|
private bool disposed;
|
|
|
|
public GateWatcherSubscription(ExprCircuitSimulator simulator, int id)
|
|
{
|
|
this.simulator = simulator;
|
|
this.id = id;
|
|
}
|
|
|
|
public void Dispose()
|
|
{
|
|
if (disposed)
|
|
{
|
|
return;
|
|
}
|
|
|
|
disposed = true;
|
|
simulator.RemoveWatcher(id);
|
|
}
|
|
}
|
|
|
|
public bool TryRunUntilStable(int maxSteps, out int steps)
|
|
{
|
|
steps = 0;
|
|
if (maxSteps <= 0)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
EnsureCompiled();
|
|
|
|
while (steps < maxSteps)
|
|
{
|
|
steps++;
|
|
computeOutputs!(inputMasks, outputMasks, sourceStates);
|
|
bool changed = PropagateAndSwapDetectChange();
|
|
NotifyWatchers();
|
|
if (!changed)
|
|
{
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
private static int[] CopyDefinitionGatesAndConnections(
|
|
ExprCircuitSimulator destination,
|
|
CircuitDefinition definition,
|
|
Func<int, GateKind, GateKind> mapKind)
|
|
{
|
|
int gateCount = definition.GateKinds.Count;
|
|
int[] map = new int[gateCount];
|
|
Array.Fill(map, -1);
|
|
|
|
// Expand nested macro instances by mapping their placeholder pin gates directly to the instantiated sub-macro pins.
|
|
for (int i = 0; i < definition.MacroInstances.Count; i++)
|
|
{
|
|
CircuitDefinition.MacroInstanceDef instanceDef = definition.MacroInstances[i];
|
|
MacroInstance instance = destination.AddMacroGate(instanceDef.Name);
|
|
|
|
if (instance.Inputs.Length != instanceDef.Inputs.Length || instance.Outputs.Length != instanceDef.Outputs.Length)
|
|
{
|
|
throw new InvalidOperationException($"Macro instance '{instanceDef.Name}' pin counts do not match the referenced macro definition.");
|
|
}
|
|
|
|
for (int p = 0; p < instanceDef.Inputs.Length; p++)
|
|
{
|
|
int gateId = instanceDef.Inputs[p];
|
|
if (map[gateId] != -1) throw new InvalidOperationException("Macro pin gate was mapped more than once.");
|
|
map[gateId] = instance.Inputs[p];
|
|
}
|
|
|
|
for (int p = 0; p < instanceDef.Outputs.Length; p++)
|
|
{
|
|
int gateId = instanceDef.Outputs[p];
|
|
if (map[gateId] != -1) throw new InvalidOperationException("Macro pin gate was mapped more than once.");
|
|
map[gateId] = instance.Outputs[p];
|
|
}
|
|
}
|
|
|
|
for (int i = 0; i < gateCount; i++)
|
|
{
|
|
if (map[i] != -1)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
map[i] = destination.AddGate(mapKind(i, definition.GateKinds[i]));
|
|
}
|
|
|
|
for (int i = 0; i < definition.Connections.Count; i++)
|
|
{
|
|
(int from, int to, byte bit) = definition.Connections[i];
|
|
destination.ConnectGates(map[from], map[to], bit);
|
|
}
|
|
|
|
return map;
|
|
}
|
|
|
|
private static int[] MapPins(IReadOnlyList<int> pins, int[] map)
|
|
{
|
|
int[] result = new int[pins.Count];
|
|
for (int i = 0; i < result.Length; i++)
|
|
{
|
|
result[i] = map[pins[i]];
|
|
}
|
|
|
|
return result;
|
|
}
|
|
}
|