Double checked locking Article

Question

I was reading this article about \"Double-Checked locking\" and out of the main topic of the article I was wondering why at some point of the article the author uses the nex

Answer 1

All right, but the article said that

The code in Listing 7 doesn't work because of the current definition of the memory model. The Java Language Specification (JLS) demands that code within a synchronized block not be moved out of a synchronized block. However, it does not say that code not in a synchronized block cannot be moved into a synchronized block.

And also seems like the JVM makes the next translation to "pseudo-code" in ASM:

public static Singleton getInstance()
{
  if (instance == null)
  {
    synchronized(Singleton.class) {      //1
      Singleton inst = instance;         //2
      if (inst == null)
      {
        synchronized(Singleton.class) {  //3
          //inst = new Singleton();      //4
          instance = new Singleton();               
        }
        //instance = inst;               //5
      }
    }
  }
  return instance;
}

So far, the point of no writes after the "instance=inst" is not accomplished?

I will read now the article, thanks for the link.