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<a name="Directives_002di960"></a>
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<p>
Next: <a href="Opcodes-for-i960.html#Opcodes-for-i960" accesskey="n" rel="next">Opcodes for i960</a>, Previous: <a href="Floating-Point_002di960.html#Floating-Point_002di960" accesskey="p" rel="prev">Floating Point-i960</a>, Up: <a href="i960_002dDependent.html#i960_002dDependent" accesskey="u" rel="up">i960-Dependent</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
<a name="i960-Machine-Directives"></a>
<h4 class="subsection">9.17.3 i960 Machine Directives</h4>

<a name="index-machine-directives_002c-i960"></a>
<a name="index-i960-machine-directives"></a>

<dl compact="compact">
<dd><a name="index-bss-directive_002c-i960"></a>
</dd>
<dt><code>.bss <var>symbol</var>, <var>length</var>, <var>align</var></code></dt>
<dd><p>Reserve <var>length</var> bytes in the bss section for a local <var>symbol</var>,
aligned to the power of two specified by <var>align</var>.  <var>length</var> and
<var>align</var> must be positive absolute expressions.  This directive
differs from &lsquo;<samp>.lcomm</samp>&rsquo; only in that it permits you to specify
an alignment.  See <a href="Lcomm.html#Lcomm"><code>.lcomm</code></a>.
</p></dd>
</dl>

<dl compact="compact">
<dd><a name="index-extended-directive_002c-i960"></a>
</dd>
<dt><code>.extended <var>flonums</var></code></dt>
<dd><p><code>.extended</code> expects zero or more flonums, separated by commas; for
each flonum, &lsquo;<samp>.extended</samp>&rsquo; emits an <small>IEEE</small> extended-format (80-bit)
floating-point number.
</p>
<a name="index-leafproc-directive_002c-i960"></a>
</dd>
<dt><code>.leafproc <var>call-lab</var>, <var>bal-lab</var></code></dt>
<dd><p>You can use the &lsquo;<samp>.leafproc</samp>&rsquo; directive in conjunction with the
optimized <code>callj</code> instruction to enable faster calls of leaf
procedures.  If a procedure is known to call no other procedures, you
may define an entry point that skips procedure prolog code (and that does
not depend on system-supplied saved context), and declare it as the
<var>bal-lab</var> using &lsquo;<samp>.leafproc</samp>&rsquo;.  If the procedure also has an
entry point that goes through the normal prolog, you can specify that
entry point as <var>call-lab</var>.
</p>
<p>A &lsquo;<samp>.leafproc</samp>&rsquo; declaration is meant for use in conjunction with the
optimized call instruction &lsquo;<samp>callj</samp>&rsquo;; the directive records the data
needed later to choose between converting the &lsquo;<samp>callj</samp>&rsquo; into a
<code>bal</code> or a <code>call</code>.
</p>
<p><var>call-lab</var> is optional; if only one argument is present, or if the
two arguments are identical, the single argument is assumed to be the
<code>bal</code> entry point.
</p>
<a name="index-sysproc-directive_002c-i960"></a>
</dd>
<dt><code>.sysproc <var>name</var>, <var>index</var></code></dt>
<dd><p>The &lsquo;<samp>.sysproc</samp>&rsquo; directive defines a name for a system procedure.
After you define it using &lsquo;<samp>.sysproc</samp>&rsquo;, you can use <var>name</var> to
refer to the system procedure identified by <var>index</var> when calling
procedures with the optimized call instruction &lsquo;<samp>callj</samp>&rsquo;.
</p>
<p>Both arguments are required; <var>index</var> must be between 0 and 31
(inclusive).
</p></dd>
</dl>

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