Division with IL and Expression Tree

Program.cs

using System;
using System.Linq.Expressions;
using System.Reflection.Emit;

namespace ConsoleApplication11
{
    class Program
    {
        static void Main(string[] args)
        {
            var divisor = CriaDivisor();
            var criaDivisorIL = CriaDivisorIL();

            Console.WriteLine("Usando Expression");
            Console.WriteLine("4 ÷ 2 = {0}", divisor(4, 2));
            Console.WriteLine("4 ÷ 0 = {0}", divisor(4, 0));
            Console.WriteLine("4 ÷ 4 = {0}", divisor(4, 4));

            Console.WriteLine("Usando IL puro");
            Console.WriteLine("2 ÷ 1 = {0}", criaDivisorIL(2, 1));
        }

        static Func<double, double, double> CriaDivisor()
        {
            var type = typeof(double);
            var valor1 = Expression.Parameter(type, "valor1");
            var valor2 = Expression.Parameter(type, "valor2");
            var resultado = Expression.Variable(type, "resultado");
            var zero = Expression.Constant(0d);

            var valor2DiferenteDe0 = Expression.NotEqual(valor2, zero);
            var divisao = Expression.Divide(valor1, valor2);
            var ifTrue = Expression.Assign(resultado, divisao);
            var ifFalse = Expression.Assign(resultado, zero);

            var ifThenElse = Expression.IfThenElse(valor2DiferenteDe0, ifTrue, ifFalse);
            var blockExpression = Expression.Block(new[] { resultado }, ifThenElse, resultado);

            var lambda = Expression.Lambda<Func<double, double, double>>(blockExpression, new[] { valor1, valor2 });
            return lambda.Compile();
        }

        static Func<double, double, double> CriaDivisorIL()
        {
            var type = typeof(double);
            var divisorIL = new DynamicMethod("DivisorIL", type, new[] {type, type});
            var il = divisorIL.GetILGenerator();
            
            var ret = il.DefineLabel();
            var load0 = il.DefineLabel();

            il.Emit(OpCodes.Ldarg_1);
            il.Emit(OpCodes.Ldc_R8,0d);
            il.Emit(OpCodes.Beq, load0);
            il.Emit(OpCodes.Ldarg_0);
            il.Emit(OpCodes.Ldarg_1);
            il.Emit(OpCodes.Div);
            il.Emit(OpCodes.Br, ret);
            il.MarkLabel(load0);
            il.Emit(OpCodes.Ldc_R8, 0d);
            il.MarkLabel(ret);
            il.Emit(OpCodes.Ret);

            return (Func<double, double, double>)divisorIL.CreateDelegate(typeof(Func<double, double, double>));
        }
    }
}