In particular, a compiler must not introduce writes that do not exist in the original program,
it must not allow a single read to observe multiple values,
and it must not allow a single write to write multiple values.
</p>

<p>
All the following examples assume that `*p` and `*q` refer to
memory locations accessible to multiple goroutines.
</p>

For example, here is a simple complete function definition. The <code>TEXT</code>
directive declares the symbol <code>runtime·profileloop</code> and the instructions
that follow form the body of the function.
The last instruction in a <code>TEXT</code> block must be some sort of jump, usually a <code>RET</code> (pseudo-)instruction.