Aggressive.cs

using System;
using System.Runtime.CompilerServices;

namespace LeckerBrot
{
	public class RowCalulator
	{
		public void Calc() {
			for (int i = 0; i < 100000000; i++) {
				double zr = 0, zi = 0;
				for (int j = 0; j < 10; j++) {
					CalculatePoint (12, 12, ref zr, ref zi);
				}

			}
		}

		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public void CalculatePoint(double cr, double ci, ref double zr, ref double zi) {
			var zr_old = zr;
			zr = (zr * zr - zi * zi) + cr;
			zi = 2 * (zi * zr_old) + ci;
		}
	}
}

ManuallyInlined.cs

using System;
using System.Runtime.CompilerServices;

namespace LeckerBrot
{
	public class RowCalulator
	{
		public void Calc() {
			for (int i = 0; i < 100000000; i++) {
				double zr = 0, zi = 0;
				for (int j = 0; j < 10; j++) {
					double cr = 12, ci = 12;

					var zr_old = zr;
					zr = (zr * zr - zi * zi) + cr;
					zi = 2 * (zi * zr_old) + ci;
				}

			}
		}

		[MethodImpl(MethodImplOptions.NoInlining)]
		public void CalculatePoint(double cr, double ci, ref double zr, ref double zi) {
		}
	}
}

NoInlining.cs

using System;
using System.Runtime.CompilerServices;

namespace LeckerBrot
{
	public class RowCalulator
	{
		public void Calc() {
			for (int i = 0; i < 100000000; i++) {
				double zr = 0, zi = 0;
				for (int j = 0; j < 10; j++) {
					CalculatePoint (12, 12, ref zr, ref zi);
				}

			}
		}

		[MethodImpl(MethodImplOptions.NoInlining)]
		public void CalculatePoint(double cr, double ci, ref double zr, ref double zi) {
			var zr_old = zr;
			zr = (zr * zr - zi * zi) + cr;
			zi = 2 * (zi * zr_old) + ci;
		}
	}
}

TestClass.cs

using System;
using System.Diagnostics;

namespace LeckerBrot
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			Stopwatch watch = new Stopwatch ();
			RowCalulator calc = new RowCalulator ();
			watch.Start ();
			calc.Calc ();
			watch.Stop ();

			Console.WriteLine (watch.ElapsedTicks);
		}
	}
}

Mono Version

$ mono --version
Mono JIT compiler version 4.0.3 (Stable 4.0.3.20/d6946b4 Tue Aug  4 09:43:57 UTC 2015)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com

Results

Profile is always release

Arch	Inlining	Time taken	Relative Time
x86	Aggressive (Attribute)	147687387	100%
x86	No Inlining (Attribute)	146419297	99.14%
x86	Manually Inlined	97312791	65.89%

Configuration

Other System Information

Processor: Intel(R) Core(TM) i7-4700MQ CPU @ 2.40GHz

$ uname -a
Linux moritz-P15SM 3.19.0-15-generic #15-Ubuntu SMP Thu Apr 16 23:32:37 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux