System.Internal中的_HACK方法的目的是什么(x64上的.net 4.0)

Question

在x64上的.net 4.0的mscorlib中,有一个类System.Internal包含三个带后缀的静态方法_HACK.有没有人知道这些方法的目的是什么？

这是.NET Reflector输出:

internal static class Internal
{
    // Methods
    private static void CommonlyUsedGenericInstantiations_HACK()
    {
        Array.Sort<double>(null);
        Array.Sort<int>(null);
        Array.Sort<IntPtr>(null);
        new ArraySegment<byte>(new byte[1], 0, 0);
        new Dictionary<char, object>();
        new Dictionary<Guid, byte>();
        new Dictionary<Guid, object>();
        new Dictionary<Guid, Guid>();
        new Dictionary<short, IntPtr>();
        new Dictionary<int, byte>();
        new Dictionary<int, int>();
        new Dictionary<int, object>();
        new Dictionary<IntPtr, bool>();
        new Dictionary<IntPtr, short>();
        new Dictionary<object, bool>();
        new Dictionary<object, char>();
        new Dictionary<object, Guid>();
        new Dictionary<object, int>();
        new Dictionary<object, long>();
        new Dictionary<uint, WeakReference>();
        new Dictionary<object, uint>();
        new Dictionary<uint, object>();
        new Dictionary<long, object>();
        new Dictionary<MemberTypes, object>();
        new EnumEqualityComparer<MemberTypes>();
        new Dictionary<object, KeyValuePair<object, object>>();
        new Dictionary<KeyValuePair<object, object>, object>();
        NullableHelper_HACK<bool>();
        NullableHelper_HACK<byte>();
        NullableHelper_HACK<char>();
        NullableHelper_HACK<DateTime>();
        NullableHelper_HACK<decimal>();
        NullableHelper_HACK<double>();
        NullableHelper_HACK<Guid>();
        NullableHelper_HACK<short>();
        NullableHelper_HACK<int>();
        NullableHelper_HACK<long>();
        NullableHelper_HACK<float>();
        NullableHelper_HACK<TimeSpan>();
        NullableHelper_HACK<DateTimeOffset>();
        new List<bool>();
        new List<byte>();
        new List<char>();
        new List<DateTime>();
        new List<decimal>();
        new List<double>();
        new List<Guid>();
        new List<short>();
        new List<int>();
        new List<long>();
        new List<TimeSpan>();
        new List<sbyte>();
        new List<float>();
        new List<ushort>();
        new List<uint>();
        new List<ulong>();
        new List<IntPtr>();
        new List<KeyValuePair<object, object>>();
        new List<GCHandle>();
        new List<DateTimeOffset>();
        RuntimeType.RuntimeTypeCache.Prejitinit_HACK();
        new CerArrayList<RuntimeMethodInfo>(0);
        new CerArrayList<RuntimeConstructorInfo>(0);
        new CerArrayList<RuntimePropertyInfo>(0);
        new CerArrayList<RuntimeEventInfo>(0);
        new CerArrayList<RuntimeFieldInfo>(0);
        new CerArrayList<RuntimeType>(0);
        new KeyValuePair<char, ushort>('\0', 0);
        new KeyValuePair<ushort, double>(0, double.MinValue);
        new KeyValuePair<object, int>(string.Empty, -2147483648);
        new KeyValuePair<int, int>(-2147483648, -2147483648);
        SZArrayHelper_HACK<bool>(null);
        SZArrayHelper_HACK<byte>(null);
        SZArrayHelper_HACK<DateTime>(null);
        SZArrayHelper_HACK<decimal>(null);
        SZArrayHelper_HACK<double>(null);
        SZArrayHelper_HACK<Guid>(null);
        SZArrayHelper_HACK<short>(null);
        SZArrayHelper_HACK<int>(null);
        SZArrayHelper_HACK<long>(null);
        SZArrayHelper_HACK<TimeSpan>(null);
        SZArrayHelper_HACK<sbyte>(null);
        SZArrayHelper_HACK<float>(null);
        SZArrayHelper_HACK<ushort>(null);
        SZArrayHelper_HACK<uint>(null);
        SZArrayHelper_HACK<ulong>(null);
        SZArrayHelper_HACK<DateTimeOffset>(null);
        SZArrayHelper_HACK<CustomAttributeTypedArgument>(null);
        SZArrayHelper_HACK<CustomAttributeNamedArgument>(null);
    }

    private static T NullableHelper_HACK<T>() where T: struct
    {
        Nullable.Compare<T>(null, null);
        Nullable.Equals<T>(null, null);
        T? nullable = null;
        return nullable.GetValueOrDefault();
    }

    private static void SZArrayHelper_HACK<T>(SZArrayHelper oSZArrayHelper)
    {
        oSZArrayHelper.get_Count<T>();
        oSZArrayHelper.get_Item<T>(0);
        oSZArrayHelper.GetEnumerator<T>();
    }
}

Answer 1

该代码似乎确保这些函数和对象已被实例化（根据@usr，NGEN 将执行这些实例化）。该技术在 C++ 中也很常见，以确保特定的模板实例被编译到库中。