DivArm64Test.csproj

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFrameworks>net8.0;net7.0;net6.0;net5.0</TargetFrameworks>
        <ImplicitUsings>enable</ImplicitUsings>
        <Nullable>enable</Nullable>
        <LangVersion>latest</LangVersion>
    </PropertyGroup>

    <ItemGroup>
      <PackageReference Include="Mono.Cecil" Version="0.11.5" />
    </ItemGroup>

</Project>

Program.cs

using Mono.Cecil;
using Mono.Cecil.Cil;

Directory.CreateDirectory("output");

const string dotnetVersion =
#if NET8_0
    "8";
#elif NET7_0
    "7";
#elif NET6_0
    "6";
#elif NET5_0
    "5";
#endif

var module = ModuleDefinition.CreateModule("Div", ModuleKind.Console);
var type = new TypeDefinition("", "Program", TypeAttributes.Public | TypeAttributes.Abstract | TypeAttributes.Sealed, module.TypeSystem.Object);
module.Types.Add(type);
var method = new MethodDefinition("Main", MethodAttributes.Public | MethodAttributes.Static, module.TypeSystem.Void);
type.Methods.Add(method);
var il = method.Body.GetILProcessor();
il.Emit(OpCodes.Ldc_R8, 1.0);
il.Emit(OpCodes.Ldc_R8, 0.0);
il.Emit(OpCodes.Div);
il.Emit(OpCodes.Conv_R8);
il.Emit(OpCodes.Conv_I8);
il.Emit(OpCodes.Call, module.ImportReference(typeof(Console).GetMethod("WriteLine", [typeof(long)])));
il.Emit(OpCodes.Ret);
module.EntryPoint = method;
module.Write("output/div.exe");

var runtimeConfigJson = $$"""
                          {
                            "runtimeOptions": {
                              "tfm": "net{{dotnetVersion}}.0",
                              "framework": {
                                "name": "Microsoft.NETCore.App",
                                "version": "{{dotnetVersion}}.0.0"
                              }
                            }
                          }
                          """;
File.WriteAllText(Path.Join("output", "div.runtimeconfig.json"), runtimeConfigJson);