PGO.cs

using System;
using System.Runtime.CompilerServices;
using System.Threading;

public class P
{
    static void Main()
    {
        for (int i = 0; i < 1000; i++)
        {
            Test(0, 0, 1);
            Thread.Yield();
        }
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    static void Test(int x, int y, int z)
    {
        // first two are always `0` so it makes sense to check `z` first
        if (x == 0 && y == 0 && z == 0)
            throw new Exception("unreachable");
        
        // so I expect PGO to roll it to 
        // if (z == 0 && x == 0 && y == 0)
        //     throw new Exception("unreachable");
    }
}