</p>

<p>
On machines where <code>SP</code> and <code>PC</code> are
traditionally aliases for a physical, numbered register,
in the Go assembler the names <code>SP</code> and <code>PC</code>
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.