C# side changes for melonDS JIT support

Author: CasualPokePlayer

src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/LibMelonDS.cs

@@ -80,6 +80,11 @@ public struct ConsoleCreationArgs
 			public bool EnableDLDI;
 			public bool EnableDSiSDCard;
 
+			public bool EnableJIT;
+			public int MaxBranchSize;
+			public bool LiteralOptimizations;
+			public bool BranchOptimizations;
+
 			public NDS.NDSSettings.AudioBitDepthType BitDepth;
 			public NDS.NDSSettings.AudioInterpolationType Interpolation;
 

src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS.IDebuggable.cs

@@ -49,7 +49,20 @@ public void SetCpuRegister(string register, int value)
 
 		public long TotalExecutedCycles => CycleCount + _core.GetCallbackCycleOffset(_console);
 
-		public IMemoryCallbackSystem MemoryCallbacks => _memoryCallbacks;
+		public IMemoryCallbackSystem MemoryCallbacks
+		{
+			get
+			{
+				if (!_activeSyncSettings.EnableJIT)
+				{
+					return _memoryCallbacks;
+				}
+
+#pragma warning disable CA1065
+				throw new NotImplementedException();
+#pragma warning restore CA1065
+			}
+		}
 
 		// FIXME: internally the code actually just does this for either bus (probably don't want to bother adding support)
 		private readonly MemoryCallbackSystem _memoryCallbacks = new([ "ARM9 System Bus" ]);
@@ -67,23 +80,23 @@ LibMelonDS.MemoryCallback CreateCallback(MemoryCallbackFlags flags, Func<bool> g
 				{
 					if (getHasCBOfType())
 					{
-						MemoryCallbacks.CallMemoryCallbacks(address, 0, rawFlags, "ARM9 System Bus");
+						_memoryCallbacks.CallMemoryCallbacks(address, 0, rawFlags, "ARM9 System Bus");
 					}
 				};
 			}
 
-			_readCallback = CreateCallback(MemoryCallbackFlags.AccessRead, () => MemoryCallbacks.HasReads);
-			_writeCallback = CreateCallback(MemoryCallbackFlags.AccessWrite, () => MemoryCallbacks.HasWrites);
-			_execCallback = CreateCallback(MemoryCallbackFlags.AccessExecute, () => MemoryCallbacks.HasExecutes);
+			_readCallback = CreateCallback(MemoryCallbackFlags.AccessRead, () => _memoryCallbacks.HasReads);
+			_writeCallback = CreateCallback(MemoryCallbackFlags.AccessWrite, () => _memoryCallbacks.HasWrites);
+			_execCallback = CreateCallback(MemoryCallbackFlags.AccessExecute, () => _memoryCallbacks.HasExecutes);
 
 			_memoryCallbacks.ActiveChanged += SetMemoryCallbacks;
 		}
 
 		private void SetMemoryCallbacks()
 		{
-			_core.SetMemoryCallback(0, MemoryCallbacks.HasReads ? _readCallback : null);
-			_core.SetMemoryCallback(1, MemoryCallbacks.HasWrites ? _writeCallback : null);
-			_core.SetMemoryCallback(2, MemoryCallbacks.HasExecutes ? _execCallback : null);
+			_core.SetMemoryCallback(0, _memoryCallbacks.HasReads ? _readCallback : null);
+			_core.SetMemoryCallback(1, _memoryCallbacks.HasWrites ? _writeCallback : null);
+			_core.SetMemoryCallback(2, _memoryCallbacks.HasExecutes ? _execCallback : null);
 		}
 	}
 }

src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS.ISettable.cs

@@ -207,6 +207,33 @@ public int GLScaleFactor
 			[DefaultValue(false)]
 			public bool GLHiResCoordinates { get; set; }
 
+			[DisplayName("Enable JIT Recompiler")]
+			[Description("Enables JIT recompilation, offering a speed boost at the cost of accuracy. Debugging tools cannot be used with the JIT. Savestate size will be much larger with the JIT.")]
+			[DefaultValue(false)]
+			public bool EnableJIT { get; set; }
+
+			[JsonIgnore]
+			private int _jitmaxbranchsize;
+
+			[DisplayName("JIT Max Branch Size")]
+			[Description("Sets the maximum size of a JIT block. Higher values gain more speed but have a higher risk of timing problems.")]
+			[DefaultValue(32)]
+			public int JITMaxBranchSize
+			{
+				get => _jitmaxbranchsize;
+				set => _jitmaxbranchsize = Math.Max(1, Math.Min(value, 32));
+			}
+
+			[DisplayName("JIT Literal Optimizations")]
+			[Description("Performs literal optimizations in the JIT recompiler.")]
+			[DefaultValue(true)]
+			public bool JITLiteralOptimizations { get; set; }
+
+			[DisplayName("JIT Branch Optimizations")]
+			[Description("Performs branch optimizations in the JIT recompiler.")]
+			[DefaultValue(true)]
+			public bool JITBranchOptimizations { get; set; }
+
 			[JsonIgnore]
 			private DateTime _initaltime;
 

src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS.cs

@@ -518,6 +518,11 @@ static void InitIv(Span<byte> iv, ReadOnlySpan<byte> nonce)
 				consoleCreationArgs.EnableDLDI = _activeSyncSettings.EnableDLDI;
 				consoleCreationArgs.EnableDSiSDCard = _activeSyncSettings.EnableDSiSDCard;
 
+				consoleCreationArgs.EnableJIT = _activeSyncSettings.EnableJIT;
+				consoleCreationArgs.MaxBranchSize = _activeSyncSettings.JITMaxBranchSize;
+				consoleCreationArgs.LiteralOptimizations = _activeSyncSettings.JITLiteralOptimizations;
+				consoleCreationArgs.BranchOptimizations = _activeSyncSettings.JITBranchOptimizations;
+
 				consoleCreationArgs.BitDepth = _settings.AudioBitDepth;
 				consoleCreationArgs.Interpolation = _settings.AudioInterpolation;
 
@@ -598,9 +603,13 @@ static void InitIv(Span<byte> iv, ReadOnlySpan<byte> nonce)
 				_disassembler = new(_core);
 				_serviceProvider.Register<IDisassemblable>(_disassembler);
 
-				const string TRACE_HEADER = "ARM9+ARM7: Opcode address, opcode, registers (r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, SP, LR, PC, Cy, CpuMode)";
-				Tracer = new TraceBuffer(TRACE_HEADER);
-				_serviceProvider.Register(Tracer);
+				// tracelogger cannot be used with the JIT
+				if (!_activeSyncSettings.EnableJIT)
+				{
+					const string TRACE_HEADER = "ARM9+ARM7: Opcode address, opcode, registers (r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, SP, LR, PC, Cy, CpuMode)";
+					Tracer = new TraceBuffer(TRACE_HEADER);
+					_serviceProvider.Register(Tracer);
+				}
 
 				if (_glContext != null)
 				{