LoopWithExit.cs

using BenchmarkDotNet.Attributes;
using System;

namespace ConsoleApplication2
{
    [Config("jobs=RyuJitX64")]
    public unsafe class LoopWithExit
    {
        public int length = 100;

        private string test1;
        private string test2;

        [Setup]
        public void Setup()
        {
            test1 = new string('A', length);
            test2 = new string('A', length);
        }

        [Benchmark]
        public bool LoopReturn()
        {
            return LoopReturn(test1, test2);
        }

        [Benchmark]
        public bool LoopGoto()
        {
            return LoopGoto(test1, test2);
        }

        public bool LoopReturn(String strA, String strB)
        {
            int length = strA.Length;

            fixed (char* ap = strA) fixed (char* bp = strB)
            {
                char* a = ap;
                char* b = bp;

                while (length != 0)
                {
                    int charA = *a;
                    int charB = *b;

                    if (charA != charB)
                        return false;

                    a++;
                    b++;
                    length--;
                }

                return true;
            }
        }

        public static bool LoopGoto(String strA, String strB)
        {
            int length = strA.Length;

            fixed (char* ap = strA) fixed (char* bp = strB)
            {
                char* a = ap;
                char* b = bp;

                while (length != 0)
                {
                    int charA = *a;
                    int charB = *b;

                    if (charA != charB)
                        goto ReturnFalse;

                    a++;
                    b++;
                    length--;
                }

                return true;

                ReturnFalse:
                return false;
            }
        }
    }
}