Cs vs Fs @ branching

Library.fs

namespace Fs
      
module Bench =
    let condition x =
        if  (x = 1 || x = 2) then 1
        elif(x = 3 || x = 4) then 2
        else 0
        
    let conditionReorder x =        
        if  (x = 4 || x = 3) then 2
        elif(x = 2 || x = 1) then 1
        else 0

    let conditionMatch x =
        match x with 
        | 1 -> 1
        | 2 -> 1
        | 3 -> 2
        | 4 -> 2
        | _ -> 0

Program.cs

using System;
using System.Reflection;
using System.Runtime.CompilerServices;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

namespace CsVsFs
{
    class Program
    {
        static void Main(string[] args)
        {
            BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args);
        }
    }

    [IterationCount(10)]
    [InvocationCount(100_000_000)]
    public class Bench22
    {
        Random rnd = new Random();
        private int x;
        public int X => rnd.Next(1, 5);

        [Benchmark]
        [Arguments(1), Arguments(2), Arguments(3), Arguments(4)]
        public int CSharp(int s) => Cond(s);

        [Benchmark]
        [Arguments(1), Arguments(2), Arguments(3), Arguments(4)]
        public int FSharp(int s) => Fs.Bench.condition(s);

        [Benchmark]
        [Arguments(1), Arguments(2), Arguments(3), Arguments(4)]
        public int FSharpReorder(int s) => Fs.Bench.conditionReorder(s);

        [Benchmark]
        [Arguments(1), Arguments(2), Arguments(3), Arguments(4)]
        public int FSharpMatch(int s) => Fs.Bench.conditionMatch(s);

        //
        // FSharp will not inline the code so we shouldn't eiter.
        //
        [MethodImpl(MethodImplOptions.NoInlining)]
        public static int Cond(int x)
        {
            if (x == 1 || x == 2) return 1;
            else if (x == 3 || x == 4) return 2;
            else return 0;
        }
    }
}

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.19041.928 (2004/?/20H1)
Intel Core i7-8700 CPU 3.20GHz (Coffee Lake), 1 CPU, 12 logical and 6 physical cores
.NET Core SDK=5.0.201
  [Host]     : .NET Core 5.0.4 (CoreCLR 5.0.421.11614, CoreFX 5.0.421.11614), X64 RyuJIT
  Job-OMFHNN : .NET Core 5.0.4 (CoreCLR 5.0.421.11614, CoreFX 5.0.421.11614), X64 RyuJIT

InvocationCount=100000000  IterationCount=10  UnrollFactor=1  

Method	s	Mean	Error	StdDev
CSharp	1	1.3916 ns	0.0109 ns	0.0072 ns
FSharp	1	0.2426 ns	0.0235 ns	0.0140 ns
FSharpReorder	1	2.0535 ns	0.0415 ns	0.0247 ns
FSharpMatch	1	0.7153 ns	0.0189 ns	0.0125 ns
CSharp	2	0.4730 ns	0.0150 ns	0.0099 ns
FSharp	2	1.8127 ns	0.0394 ns	0.0235 ns
FSharpReorder	2	0.9916 ns	0.0999 ns	0.0594 ns
FSharpMatch	2	1.1846 ns	0.0223 ns	0.0133 ns
CSharp	3	0.9599 ns	0.0138 ns	0.0091 ns
FSharp	3	0.9485 ns	0.0174 ns	0.0103 ns
FSharpReorder	3	2.0576 ns	0.0305 ns	0.0202 ns
FSharpMatch	3	0.9495 ns	0.0263 ns	0.0174 ns
CSharp	4	0.7171 ns	0.0158 ns	0.0105 ns
FSharp	4	2.0513 ns	0.0335 ns	0.0199 ns
FSharpReorder	4	0.4725 ns	0.0171 ns	0.0113 ns
FSharpMatch	4	0.9534 ns	0.0175 ns	0.0104 ns