For example, the <code>twoprint</code> program might be
incorrectly written as:
</p>

<pre>
var a string
var done bool

func setup() {
	a = "hello, world"
	done = true
}

func doprint() {
	if !done {
		once.Do(setup)
	}
	print(a)
}

func twoprint() {
	go doprint()
	go doprint()
}
</pre>

<p>

are still treated specially;
for instance, references to <code>SP</code> require a symbol,
much like <code>FP</code>.
To access the actual hardware register use the true <code>R</code> name.
For example, on the ARM architecture the hardware
<code>SP</code> and <code>PC</code> are accessible as
<code>R13</code> and <code>R15</code>.
</p>

<p>