For example, on essentially all CPUs, it is valid to rewrite
</p>

<pre>
n := 0
for i := 0; i < m; i++ {
	n += *shared
}
</pre>

into:

<pre>
n := 0
local := *shared
for i := 0; i < m; i++ {
	n += local
}
</pre>

<p>
provided it can be proved that <code>*shared</code> will not fault on access,
because the potential added read will not affect any existing concurrent reads or writes.

</p>

<p>
The <code>GLOBL</code> directive declares a symbol to be global.
The arguments are optional flags and the size of the data being declared as a global,
which will have initial value all zeros unless a <code>DATA</code> directive
has initialized it.
The <code>GLOBL</code> directive must follow any corresponding <code>DATA</code> directives.
</p>

<p>