Code Contract Performance Analysis

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ContractBenchmarker {
    class Program {
        private delegate Int32 testMethod(Int32 x, Int32 y);

        static void Main(string[] args) {
            const Int32 ITERATIONS = 10000;

            foreach (testMethod tm in new testMethod[] { new testMethod(Add), 
                                                         new testMethod(IfCheckedAdd), 
                                                         new testMethod(AssertCheckedAdd),
                                                         new testMethod(ContractCheckedAdd) }) {
                DateTime start = DateTime.Now;

                for (Int32 i = 0; i < ITERATIONS; i++)
                    for (Int32 j = 0; j < ITERATIONS; j++)
                        tm(i, j);

                System.Console.WriteLine(tm.Method.Name + " " + (DateTime.Now - start).TotalMilliseconds.ToString());
            }

            System.Console.ReadLine();
        }

        private static Int32 Add(Int32 x, Int32 y) {
            if (x == y)
                return x * 2;

            return x + y;
        }

        private static Int32 IfCheckedAdd(Int32 x, Int32 y) {
            if (x < 0) throw new InvalidOperationException("X must be greater than 0");

            if (x == y) {
                if (x * 2 < 0) throw new InvalidOperationException("Result must be positive");

                return x * 2;
            }

            if (x + y < 0) throw new InvalidOperationException("Result must be positive");
            return x + y;
        }

        private static Int32 AssertCheckedAdd(Int32 x, Int32 y) {
            System.Diagnostics.Debug.Assert(x >= 0);

            if (x == y) {
                System.Diagnostics.Debug.Assert(x * 2 >= 0);

                return x * 2;
            }

            System.Diagnostics.Debug.Assert(x + y >= 0);
            return x + y;
        }

        private static Int32 ContractCheckedAdd(Int32 x, Int32 y) {
            System.Diagnostics.Contracts.Contract.Requires(x >= 0, "X must be greater than 0");
            System.Diagnostics.Contracts.Contract.Ensures(System.Diagnostics.Contracts.Contract.Result<Int32>() >= 0, "Result must be positive");

            if (x == y)
                return x * 2;

            return x + y;
        }
    }
}