1 files changed, 105 insertions, 0 deletions
diff --git a/Ryujinx.HLE/HOS/Tamper/CodeEmitters/Arithmetic.cs b/Ryujinx.HLE/HOS/Tamper/CodeEmitters/Arithmetic.cs
new file mode 100644
index 00000000..b7d46d3a
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Tamper/CodeEmitters/Arithmetic.cs
@@ -0,0 +1,105 @@
+using Ryujinx.HLE.Exceptions;
+using Ryujinx.HLE.HOS.Tamper.Operations;
+using System;
+using System.Collections.Generic;
+
+namespace Ryujinx.HLE.HOS.Tamper.CodeEmitters
+{
+    /// <summary>
+    /// Code type 9 allows performing arithmetic on registers.
+    /// </summary>
+    class Arithmetic
+    {
+        private const int OperationWidthIndex = 1;
+        private const int OperationTypeIndex = 2;
+        private const int DestinationRegisterIndex = 3;
+        private const int LeftHandSideRegisterIndex = 4;
+        private const int UseImmediateAsRhsIndex = 5;
+        private const int RightHandSideRegisterIndex = 6;
+        private const int RightHandSideImmediateIndex = 8;
+
+        private const int RightHandSideImmediate8 = 8;
+        private const int RightHandSideImmediate16 = 16;
+
+        private const byte Add = 0; // lhs + rhs
+        private const byte Sub = 1; // lhs - rhs
+        private const byte Mul = 2; // lhs * rhs
+        private const byte Lsh = 3; // lhs << rhs
+        private const byte Rsh = 4; // lhs >> rhs
+        private const byte And = 5; // lhs & rhs
+        private const byte Or  = 6; // lhs | rhs
+        private const byte Not = 7; // ~lhs (discards right-hand operand)
+        private const byte Xor = 8; // lhs ^ rhs
+        private const byte Mov = 9; // lhs (discards right-hand operand)
+
+        public static void Emit(byte[] instruction, CompilationContext context)
+        {
+            // 9TCRS0s0
+            // T: Width of arithmetic operation(1, 2, 4, or 8 bytes).
+            // C: Arithmetic operation to apply, see below.
+            // R: Register to store result in.
+            // S: Register to use as left - hand operand.
+            // s: Register to use as right - hand operand.
+
+            // 9TCRS100 VVVVVVVV (VVVVVVVV)
+            // T: Width of arithmetic operation(1, 2, 4, or 8 bytes).
+            // C: Arithmetic operation to apply, see below.
+            // R: Register to store result in.
+            // S: Register to use as left - hand operand.
+            // V: Value to use as right - hand operand.
+
+            byte operationWidth = instruction[OperationWidthIndex];
+            byte operation = instruction[OperationTypeIndex];
+            Register destinationRegister = context.GetRegister(instruction[DestinationRegisterIndex]);
+            Register leftHandSideRegister = context.GetRegister(instruction[LeftHandSideRegisterIndex]);
+            byte rightHandSideIsImmediate = instruction[UseImmediateAsRhsIndex];
+            IOperand rightHandSideOperand;
+
+            switch (rightHandSideIsImmediate)
+            {
+                case 0:
+                    // Use a register as right-hand side.
+                    rightHandSideOperand = context.GetRegister(instruction[RightHandSideRegisterIndex]);
+                    break;
+                case 1:
+                    // Use an immediate as right-hand side.
+                    int immediateSize = operationWidth <= 4 ? RightHandSideImmediate8 : RightHandSideImmediate16;
+                    ulong immediate = InstructionHelper.GetImmediate(instruction, RightHandSideImmediateIndex, immediateSize);
+                    rightHandSideOperand = new Value<ulong>(immediate);
+                    break;
+                default:
+                    throw new TamperCompilationException($"Invalid right-hand side switch {rightHandSideIsImmediate} in Atmosphere cheat");
+            }
+
+            void Emit(Type operationType, IOperand rhs = null)
+            {
+                List<IOperand> operandList = new List<IOperand>();
+                operandList.Add(destinationRegister);
+                operandList.Add(leftHandSideRegister);
+
+                if (rhs != null)
+                {
+                    operandList.Add(rhs);
+                }
+
+                InstructionHelper.Emit(operationType, operationWidth, context, operandList.ToArray());
+            }
+
+            switch (operation)
+            {
+                case Add: Emit(typeof(OpAdd<>), rightHandSideOperand); break;
+                case Sub: Emit(typeof(OpSub<>), rightHandSideOperand); break;
+                case Mul: Emit(typeof(OpMul<>), rightHandSideOperand); break;
+                case Lsh: Emit(typeof(OpLsh<>), rightHandSideOperand); break;
+                case Rsh: Emit(typeof(OpRsh<>), rightHandSideOperand); break;
+                case And: Emit(typeof(OpAnd<>), rightHandSideOperand); break;
+                case Or:  Emit(typeof(OpOr<> ), rightHandSideOperand); break;
+                case Not: Emit(typeof(OpNot<>)                      ); break;
+                case Xor: Emit(typeof(OpXor<>), rightHandSideOperand); break;
+                case Mov: Emit(typeof(OpMov<>)                      ); break;
+                default:
+                    throw new TamperCompilationException($"Invalid arithmetic operation {operation} in Atmosphere cheat");
+            }
+        }
+    }
+}