Mono.Cecil.Rocks.MethodBodyRocks.OptimizeMacros C# (CSharp) Method

        public static void OptimizeMacros(this MethodBody self)
        {
            if (self == null)
                throw new ArgumentNullException ("self");

            var method = self.Method;

            foreach (var instruction in self.Instructions) {
                int index;
                switch (instruction.OpCode.Code) {
                case Code.Ldarg:
                    index = ((ParameterDefinition) instruction.Operand).Index;
                    if (index == -1 && instruction.Operand == self.ThisParameter)
                        index = 0;
                    else if (method.HasThis)
                        index++;

                    switch (index) {
                    case 0:
                        MakeMacro (instruction, OpCodes.Ldarg_0);
                        break;
                    case 1:
                        MakeMacro (instruction, OpCodes.Ldarg_1);
                        break;
                    case 2:
                        MakeMacro (instruction, OpCodes.Ldarg_2);
                        break;
                    case 3:
                        MakeMacro (instruction, OpCodes.Ldarg_3);
                        break;
                    default:
                        if (index < 256)
                            ExpandMacro (instruction, OpCodes.Ldarg_S, instruction.Operand);
                        break;
                    }
                    break;
                case Code.Ldloc:
                    index = ((VariableDefinition) instruction.Operand).Index;
                    switch (index) {
                    case 0:
                        MakeMacro (instruction, OpCodes.Ldloc_0);
                        break;
                    case 1:
                        MakeMacro (instruction, OpCodes.Ldloc_1);
                        break;
                    case 2:
                        MakeMacro (instruction, OpCodes.Ldloc_2);
                        break;
                    case 3:
                        MakeMacro (instruction, OpCodes.Ldloc_3);
                        break;
                    default:
                        if (index < 256)
                            ExpandMacro (instruction, OpCodes.Ldloc_S, instruction.Operand);
                        break;
                    }
                    break;
                case Code.Stloc:
                    index = ((VariableDefinition) instruction.Operand).Index;
                    switch (index) {
                    case 0:
                        MakeMacro (instruction, OpCodes.Stloc_0);
                        break;
                    case 1:
                        MakeMacro (instruction, OpCodes.Stloc_1);
                        break;
                    case 2:
                        MakeMacro (instruction, OpCodes.Stloc_2);
                        break;
                    case 3:
                        MakeMacro (instruction, OpCodes.Stloc_3);
                        break;
                    default:
                        if (index < 256)
                            ExpandMacro (instruction, OpCodes.Stloc_S, instruction.Operand);
                        break;
                    }
                    break;
                case Code.Ldarga:
                    index = ((ParameterDefinition) instruction.Operand).Index;
                    if (index == -1 && instruction.Operand == self.ThisParameter)
                        index = 0;
                    else if (method.HasThis)
                        index++;
                    if (index < 256)
                        ExpandMacro (instruction, OpCodes.Ldarga_S, instruction.Operand);
                    break;
                case Code.Ldloca:
                    if (((VariableDefinition) instruction.Operand).Index < 256)
                        ExpandMacro (instruction, OpCodes.Ldloca_S, instruction.Operand);
                    break;
                case Code.Ldc_I4:
                    int i = (int) instruction.Operand;
                    switch (i) {
                    case -1:
                        MakeMacro (instruction, OpCodes.Ldc_I4_M1);
                        break;
                    case 0:
                        MakeMacro (instruction, OpCodes.Ldc_I4_0);
                        break;
                    case 1:
                        MakeMacro (instruction, OpCodes.Ldc_I4_1);
                        break;
                    case 2:
                        MakeMacro (instruction, OpCodes.Ldc_I4_2);
                        break;
                    case 3:
                        MakeMacro (instruction, OpCodes.Ldc_I4_3);
                        break;
                    case 4:
                        MakeMacro (instruction, OpCodes.Ldc_I4_4);
                        break;
                    case 5:
                        MakeMacro (instruction, OpCodes.Ldc_I4_5);
                        break;
                    case 6:
                        MakeMacro (instruction, OpCodes.Ldc_I4_6);
                        break;
                    case 7:
                        MakeMacro (instruction, OpCodes.Ldc_I4_7);
                        break;
                    case 8:
                        MakeMacro (instruction, OpCodes.Ldc_I4_8);
                        break;
                    default:
                        if (i >= -128 && i < 128)
                            ExpandMacro (instruction, OpCodes.Ldc_I4_S, (sbyte) i);
                        break;
                    }
                    break;
                }
            }

            OptimizeBranches (self);
        }