urned off.</b> If one is turned on,
the result of executing that instruction is undefined.
</p>

<p>
Internally, the emulator uses structs with
<a href="http://en.cppreference.com/w/cpp/language/bit_field">bit fields</a> to
represent instructions. It uses bit fields only to save space; they can be
removed with no consequences.
</p>

<div class="org-src-container">

<pre class="src src-c" id="mode_representation">/* Options for operand use. Is space C an immediate value or a register? Should
 * any of spaces