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<title>Using the GNU Compiler Collection (GCC): ARC Function Attributes</title>
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<a name="ARC-Function-Attributes"></a>
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<p>
Next: <a href="ARM-Function-Attributes.html#ARM-Function-Attributes" accesskey="n" rel="next">ARM Function Attributes</a>, Previous: <a href="AMD-GCN-Function-Attributes.html#AMD-GCN-Function-Attributes" accesskey="p" rel="previous">AMD GCN Function Attributes</a>, Up: <a href="Function-Attributes.html#Function-Attributes" accesskey="u" rel="up">Function Attributes</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="ARC-Function-Attributes-1"></a>
<h4 class="subsection">6.33.4 ARC Function Attributes</h4>
<p>These function attributes are supported by the ARC back end:
</p>
<dl compact="compact">
<dd><a name="index-interrupt-function-attribute_002c-ARC"></a>
</dd>
<dt><code>interrupt</code></dt>
<dd><p>Use this attribute to indicate
that the specified function is an interrupt handler. The compiler generates
function entry and exit sequences suitable for use in an interrupt handler
when this attribute is present.
</p>
<p>On the ARC, you must specify the kind of interrupt to be handled
in a parameter to the interrupt attribute like this:
</p>
<div class="smallexample">
<pre class="smallexample">void f () __attribute__ ((interrupt ("ilink1")));
</pre></div>
<p>Permissible values for this parameter are: <code>ilink1</code><!-- /@w --> and
<code>ilink2</code><!-- /@w --> for ARCv1 architecture, and <code>ilink</code><!-- /@w --> and
<code>firq</code><!-- /@w --> for ARCv2 architecture.
</p>
<a name="index-long_005fcall-function-attribute_002c-ARC"></a>
<a name="index-medium_005fcall-function-attribute_002c-ARC"></a>
<a name="index-short_005fcall-function-attribute_002c-ARC"></a>
<a name="index-indirect-calls_002c-ARC"></a>
</dd>
<dt><code>long_call</code></dt>
<dt><code>medium_call</code></dt>
<dt><code>short_call</code></dt>
<dd><p>These attributes specify how a particular function is called.
These attributes override the
<samp>-mlong-calls</samp> and <samp>-mmedium-calls</samp> (see <a href="ARC-Options.html#ARC-Options">ARC Options</a>)
command-line switches and <code>#pragma long_calls</code> settings.
</p>
<p>For ARC, a function marked with the <code>long_call</code> attribute is
always called using register-indirect jump-and-link instructions,
thereby enabling the called function to be placed anywhere within the
32-bit address space. A function marked with the <code>medium_call</code>
attribute will always be close enough to be called with an unconditional
branch-and-link instruction, which has a 25-bit offset from
the call site. A function marked with the <code>short_call</code>
attribute will always be close enough to be called with a conditional
branch-and-link instruction, which has a 21-bit offset from
the call site.
</p>
<a name="index-jli_005falways-function-attribute_002c-ARC"></a>
</dd>
<dt><code>jli_always</code></dt>
<dd><p>Forces a particular function to be called using <code>jli</code>
instruction. The <code>jli</code> instruction makes use of a table stored
into <code>.jlitab</code> section, which holds the location of the functions
which are addressed using this instruction.
</p>
<a name="index-jli_005ffixed-function-attribute_002c-ARC"></a>
</dd>
<dt><code>jli_fixed</code></dt>
<dd><p>Identical like the above one, but the location of the function in the
<code>jli</code> table is known and given as an attribute parameter.
</p>
<a name="index-secure_005fcall-function-attribute_002c-ARC"></a>
</dd>
<dt><code>secure_call</code></dt>
<dd><p>This attribute allows one to mark secure-code functions that are
callable from normal mode. The location of the secure call function
into the <code>sjli</code> table needs to be passed as argument.
</p>
<a name="index-naked-function-attribute_002c-ARC"></a>
</dd>
<dt><code>naked</code></dt>
<dd><p>This attribute allows the compiler to construct the requisite function
declaration, while allowing the body of the function to be assembly
code. The specified function will not have prologue/epilogue
sequences generated by the compiler. Only basic <code>asm</code> statements
can safely be included in naked functions (see <a href="Basic-Asm.html#Basic-Asm">Basic Asm</a>). While
using extended <code>asm</code> or a mixture of basic <code>asm</code> and C code
may appear to work, they cannot be depended upon to work reliably and
are not supported.
</p>
</dd>
</dl>
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Next: <a href="ARM-Function-Attributes.html#ARM-Function-Attributes" accesskey="n" rel="next">ARM Function Attributes</a>, Previous: <a href="AMD-GCN-Function-Attributes.html#AMD-GCN-Function-Attributes" accesskey="p" rel="previous">AMD GCN Function Attributes</a>, Up: <a href="Function-Attributes.html#Function-Attributes" accesskey="u" rel="up">Function Attributes</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html#Indices" title="Index" rel="index">Index</a>]</p>
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