就像the documentation for the /optimize compiler flag这样一个例子

The /optimize option enables or disables optimizations performed by the compiler to make your output file smaller,faster,and more efficient.

这意味着语言编译器至少应用一些优化.

不过,与Try Roslyn一起玩,似乎并非如此.看起来C#编译器根本没有优化.

例子

输入：

bool y = true;
if (y)
    Console.WriteLine("yo");

Decompiled output:

if (true)
{
    Console.WriteLine("yo");
}

输入：

static void DoNothing() { }

static void Main(string[] args)
{
    DoNothing();
    Console.WriteLine("Hello world!");
}

Decompiled output:

private static void DoNothing()
{
}
private static void Main(string[] args)
{
    NormalProgram.DoNothing();
    Console.WriteLine("Hello world!");
}

输入：

try
{
    throw new Exception();
}
catch (Exception)
{
    Console.WriteLine("Hello world!");
}

Decompiled output:

try
{
    throw new Exception();
}
catch (Exception)
{
    Console.WriteLine("Hello world!");
}

如您所见,C#语言编译器似乎完全没有优化.

这是真的？如果是这样,为什么文档声称/ optimize会使您的可执行文件更小？