Performance of Compiled Expression Tree

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I have a simple scenario, where i am trying to test the performance of a expression compiled tree on an list of stock objects. Below is the code

The performance of expression compiled tree is 5x slower than static lambda call. I am not sure whether this is a standard performance one can expect with expression compiled tree. Would appreciate any insight.

LambdaExpression();
List<Stock> stocks = new List<Stock>();
for (int ctr = 0; ctr <= 5000000; ctr++)
{
    Stock stk1 = new Stock() { Price = ctr, Symbol = "A", CloseDate = DateTime.Now, FaceValue = ctr } ;
    stocks.Add(stk1);
}
CompileTimeLamda(a);
DynamicLambda(a);


public static void LambdaExpression()
{
    ParameterExpression CS1 = Expression.Parameter(typeof(Stock), "d");

    var line1 = Expression.Equal(Expression.Property(CS1, typeof(Stock).GetProperty("Symbol")), Expression.Constant("MSFT", typeof(string)));
    var line2 = Expression.GreaterThan(Expression.Property(Expression.Property(CS1, typeof(Stock).GetProperty("CloseDate")),typeof(DateTime).GetProperty("Millisecond")), 
                                 Expression.Constant(0, typeof(int)));
    var line3 = Expression.GreaterThan(Expression.Property(CS1, typeof(Stock).GetProperty("Price")), Expression.Constant((double)0, typeof(double)));
    var line4 = Expression.And(line1,line2);
    var line5 = Expression.OrElse(line4, line3);

    func = Expression.Lambda<Func<Stock, bool>>(line5, new ParameterExpression[] {  CS1 } ).Compile();
}


public static void DynamicLambda(List<Stock> stks)
{
    Stopwatch watch = new Stopwatch();
    watch.Start();
    foreach (var d in stks)
    {
        func(d);
    }
    watch.Stop();
    Console.WriteLine("Dynamic Lambda :" + watch.ElapsedMilliseconds);
}

public static void CompileTimeLamda(List<Stock> stks)
{
    Stopwatch watch = new Stopwatch();
    watch.Start();
    foreach (var d in stks)
    {
        if (d.Symbol == "MSFT" && d.CloseDate.Millisecond > 0 ||
                                  (d.Price) > 0) ;
    }
    watch.Stop();
    Console.WriteLine("Compile Time Lamda " +watch.ElapsedMilliseconds);
}
3 Answers
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