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<h4 class="subsection">9.52.5 Directives</h4>
<p><a name="index-Xtensa-directives-2486"></a><a name="index-directives_002c-Xtensa-2487"></a>
The Xtensa assembler supports a region-based directive syntax:
<pre class="smallexample"> .begin <var>directive</var> [<var>options</var>]
...
.end <var>directive</var>
</pre>
<p>All the Xtensa-specific directives that apply to a region of code use
this syntax.
<p>The directive applies to code between the <code>.begin</code> and the
<code>.end</code>. The state of the option after the <code>.end</code> reverts to
what it was before the <code>.begin</code>.
A nested <code>.begin</code>/<code>.end</code> region can further
change the state of the directive without having to be aware of its
outer state. For example, consider:
<pre class="smallexample"> .begin no-transform
L: add a0, a1, a2
.begin transform
M: add a0, a1, a2
.end transform
N: add a0, a1, a2
.end no-transform
</pre>
<p>The <code>ADD</code> opcodes at <code>L</code> and <code>N</code> in the outer
<code>no-transform</code> region both result in <code>ADD</code> machine instructions,
but the assembler selects an <code>ADD.N</code> instruction for the
<code>ADD</code> at <code>M</code> in the inner <code>transform</code> region.
<p>The advantage of this style is that it works well inside macros which can
preserve the context of their callers.
<p>The following directives are available:
<ul class="menu">
<li><a accesskey="1" href="Schedule-Directive.html#Schedule-Directive">Schedule Directive</a>: Enable instruction scheduling.
<li><a accesskey="2" href="Longcalls-Directive.html#Longcalls-Directive">Longcalls Directive</a>: Use Indirect Calls for Greater Range.
<li><a accesskey="3" href="Transform-Directive.html#Transform-Directive">Transform Directive</a>: Disable All Assembler Transformations.
<li><a accesskey="4" href="Literal-Directive.html#Literal-Directive">Literal Directive</a>: Intermix Literals with Instructions.
<li><a accesskey="5" href="Literal-Position-Directive.html#Literal-Position-Directive">Literal Position Directive</a>: Specify Inline Literal Pool Locations.
<li><a accesskey="6" href="Literal-Prefix-Directive.html#Literal-Prefix-Directive">Literal Prefix Directive</a>: Specify Literal Section Name Prefix.
<li><a accesskey="7" href="Absolute-Literals-Directive.html#Absolute-Literals-Directive">Absolute Literals Directive</a>: Control PC-Relative vs. Absolute Literals.
</ul>
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