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  1. PO
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    <p>As Hans mentions in the comments on your question, the <code>Execute</code> method is so simple that it's almost certainly being inlined by the jitter in your "native" test.</p> <p>So what you're seeing isn't a comparison between a standard method call and a delegate invocation, but a comparison between an inlined <code>i * 2</code> operation and a delegate invocation. (And that <code>i * 2</code> operation probably boils down to just a single machine instruction, about as fast as you can get.)</p> <p>Make your <code>Execute</code> methods a bit more complicated to prevent inlining (and/or do it with the <a href="http://msdn.microsoft.com/en-us/library/system.runtime.compilerservices.methodimploptions.aspx" rel="nofollow"><code>MethodImplOptions.NoInlining</code></a> compiler hint); then you'll get a more realistic comparison between standard method calls and delegate invocations. Chances are that the difference will be negligible in most situations:</p> <pre><code>[MethodImpl(MethodImplOptions.NoInlining)] static int Execute(int i) { return ((i / 63.53) == 34.23) ? -1 : (i * 2); } public static volatile int Result; private static void Main(string[] args) { const int iterations = 100000000; { Result = Execute(42); // pre-jit var s = Stopwatch.StartNew(); for (int i = 0; i &lt; iterations; i++) { Result = Execute(i); } s.Stop(); Console.WriteLine("Native: " + s.ElapsedMilliseconds); } { Func&lt;int, int&gt; func; using (var cscp = new CSharpCodeProvider()) { var cp = new CompilerParameters { GenerateInMemory = true, CompilerOptions = @"/optimize" }; string src = @"public static class Foo { public static int Execute(int i) { return ((i / 63.53) == 34.23) ? -1 : (i * 2); } }"; var cr = cscp.CompileAssemblyFromSource(cp, src); var mi = cr.CompiledAssembly.GetType("Foo").GetMethod("Execute"); func = (Func&lt;int, int&gt;)Delegate.CreateDelegate(typeof(Func&lt;int, int&gt;), mi); } Result = func(42); // pre-jit var s = Stopwatch.StartNew(); for (int i = 0; i &lt; iterations; i++) { Result = func(i); } s.Stop(); Console.WriteLine("Dynamic delegate: " + s.ElapsedMilliseconds); } { Func&lt;int, int&gt; func = Execute; Result = func(42); // pre-jit var s = Stopwatch.StartNew(); for (int i = 0; i &lt; iterations; i++) { Result = func(i); } s.Stop(); Console.WriteLine("Delegate: " + s.ElapsedMilliseconds); } } </code></pre>
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    1. USLukeH
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    1. COI added the no-inline hint and re-ran the test, and you are spot on. Delegates are only about 50% slower. What was odd, though, is the call to the dynamically compiled method was consistently faster than the call the the native method by a factor of 91% of the time. I wonder why that is.
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