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<title>Using the GNU Compiler Collection (GCC): ARC Built-in Functions</title>

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<a name="ARC-Built_002din-Functions"></a>
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<p>
Next: <a href="ARC-SIMD-Built_002din-Functions.html#ARC-SIMD-Built_002din-Functions" accesskey="n" rel="next">ARC SIMD Built-in Functions</a>, Previous: <a href="Altera-Nios-II-Built_002din-Functions.html#Altera-Nios-II-Built_002din-Functions" accesskey="p" rel="prev">Altera Nios II Built-in Functions</a>, Up: <a href="Target-Builtins.html#Target-Builtins" accesskey="u" rel="up">Target Builtins</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="ARC-Built_002din-Functions-1"></a>
<h4 class="subsection">6.60.4 ARC Built-in Functions</h4>

<p>The following built-in functions are provided for ARC targets.  The
built-ins generate the corresponding assembly instructions.  In the
examples given below, the generated code often requires an operand or
result to be in a register.  Where necessary further code will be
generated to ensure this is true, but for brevity this is not
described in each case.
</p>
<p><em>Note:</em> Using a built-in to generate an instruction not supported
by a target may cause problems. At present the compiler is not
guaranteed to detect such misuse, and as a result an internal compiler
error may be generated.
</p>
<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005faligned"></a>Built-in Function: <em>int</em> <strong>__builtin_arc_aligned</strong> <em>(void *<var>val</var>, int <var>alignval</var>)</em></dt>
<dd><p>Return 1 if <var>val</var> is known to have the byte alignment given
by <var>alignval</var>, otherwise return 0.
Note that this is different from
</p><div class="smallexample">
<pre class="smallexample">__alignof__(*(char *)<var>val</var>) &gt;= alignval
</pre></div>
<p>because __alignof__ sees only the type of the dereference, whereas
__builtin_arc_align uses alignment information from the pointer
as well as from the pointed-to type.
The information available will depend on optimization level.
</p></dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fbrk"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_brk</strong> <em>(void)</em></dt>
<dd><p>Generates
</p><div class="example">
<pre class="example">brk
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fcore_005fread"></a>Built-in Function: <em>unsigned int</em> <strong>__builtin_arc_core_read</strong> <em>(unsigned int <var>regno</var>)</em></dt>
<dd><p>The operand is the number of a register to be read.  Generates:
</p><div class="example">
<pre class="example">mov  <var>dest</var>, r<var>regno</var>
</pre></div>
<p>where the value in <var>dest</var> will be the result returned from the
built-in.
</p></dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fcore_005fwrite"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_core_write</strong> <em>(unsigned int <var>regno</var>, unsigned int <var>val</var>)</em></dt>
<dd><p>The first operand is the number of a register to be written, the
second operand is a compile time constant to write into that
register.  Generates:
</p><div class="example">
<pre class="example">mov  r<var>regno</var>, <var>val</var>
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fdivaw"></a>Built-in Function: <em>int</em> <strong>__builtin_arc_divaw</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dd><p>Only available if either <samp>-mcpu=ARC700</samp> or <samp>-meA</samp> is set.
Generates:
</p><div class="example">
<pre class="example">divaw  <var>dest</var>, <var>a</var>, <var>b</var>
</pre></div>
<p>where the value in <var>dest</var> will be the result returned from the
built-in.
</p></dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fflag"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_flag</strong> <em>(unsigned int <var>a</var>)</em></dt>
<dd><p>Generates
</p><div class="example">
<pre class="example">flag  <var>a</var>
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005flr"></a>Built-in Function: <em>unsigned int</em> <strong>__builtin_arc_lr</strong> <em>(unsigned int <var>auxr</var>)</em></dt>
<dd><p>The operand, <var>auxv</var>, is the address of an auxiliary register and
must be a compile time constant.  Generates:
</p><div class="example">
<pre class="example">lr  <var>dest</var>, [<var>auxr</var>]
</pre></div>
<p>Where the value in <var>dest</var> will be the result returned from the
built-in.
</p></dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fmul64"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_mul64</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dd><p>Only available with <samp>-mmul64</samp>.  Generates:
</p><div class="example">
<pre class="example">mul64  <var>a</var>, <var>b</var>
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fmulu64"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_mulu64</strong> <em>(unsigned int <var>a</var>, unsigned int <var>b</var>)</em></dt>
<dd><p>Only available with <samp>-mmul64</samp>.  Generates:
</p><div class="example">
<pre class="example">mulu64  <var>a</var>, <var>b</var>
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fnop"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_nop</strong> <em>(void)</em></dt>
<dd><p>Generates:
</p><div class="example">
<pre class="example">nop
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fnorm"></a>Built-in Function: <em>int</em> <strong>__builtin_arc_norm</strong> <em>(int <var>src</var>)</em></dt>
<dd><p>Only valid if the &lsquo;<samp>norm</samp>&rsquo; instruction is available through the
<samp>-mnorm</samp> option or by default with <samp>-mcpu=ARC700</samp>.
Generates:
</p><div class="example">
<pre class="example">norm  <var>dest</var>, <var>src</var>
</pre></div>
<p>Where the value in <var>dest</var> will be the result returned from the
built-in.
</p></dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fnormw"></a>Built-in Function: <em>short int</em> <strong>__builtin_arc_normw</strong> <em>(short int <var>src</var>)</em></dt>
<dd><p>Only valid if the &lsquo;<samp>normw</samp>&rsquo; instruction is available through the
<samp>-mnorm</samp> option or by default with <samp>-mcpu=ARC700</samp>.
Generates:
</p><div class="example">
<pre class="example">normw  <var>dest</var>, <var>src</var>
</pre></div>
<p>Where the value in <var>dest</var> will be the result returned from the
built-in.
</p></dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005frtie"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_rtie</strong> <em>(void)</em></dt>
<dd><p>Generates:
</p><div class="example">
<pre class="example">rtie
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fsleep"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_sleep</strong> <em>(int <var>a</var></em></dt>
<dd><p>Generates:
</p><div class="example">
<pre class="example">sleep  <var>a</var>
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fsr"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_sr</strong> <em>(unsigned int <var>auxr</var>, unsigned int <var>val</var>)</em></dt>
<dd><p>The first argument, <var>auxv</var>, is the address of an auxiliary
register, the second argument, <var>val</var>, is a compile time constant
to be written to the register.  Generates:
</p><div class="example">
<pre class="example">sr  <var>auxr</var>, [<var>val</var>]
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fswap"></a>Built-in Function: <em>int</em> <strong>__builtin_arc_swap</strong> <em>(int <var>src</var>)</em></dt>
<dd><p>Only valid with <samp>-mswap</samp>.  Generates:
</p><div class="example">
<pre class="example">swap  <var>dest</var>, <var>src</var>
</pre></div>
<p>Where the value in <var>dest</var> will be the result returned from the
built-in.
</p></dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fswi"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_swi</strong> <em>(void)</em></dt>
<dd><p>Generates:
</p><div class="example">
<pre class="example">swi
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005fsync"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_sync</strong> <em>(void)</em></dt>
<dd><p>Only available with <samp>-mcpu=ARC700</samp>.  Generates:
</p><div class="example">
<pre class="example">sync
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005ftrap_005fs"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_trap_s</strong> <em>(unsigned int <var>c</var>)</em></dt>
<dd><p>Only available with <samp>-mcpu=ARC700</samp>.  Generates:
</p><div class="example">
<pre class="example">trap_s  <var>c</var>
</pre></div>
</dd></dl>

<dl>
<dt><a name="index-_005f_005fbuiltin_005farc_005funimp_005fs"></a>Built-in Function: <em>void</em> <strong>__builtin_arc_unimp_s</strong> <em>(void)</em></dt>
<dd><p>Only available with <samp>-mcpu=ARC700</samp>.  Generates:
</p><div class="example">
<pre class="example">unimp_s
</pre></div>
</dd></dl>

<p>The instructions generated by the following builtins are not
considered as candidates for scheduling.  They are not moved around by
the compiler during scheduling, and thus can be expected to appear
where they are put in the C code:
</p><div class="example">
<pre class="example">__builtin_arc_brk()
__builtin_arc_core_read()
__builtin_arc_core_write()
__builtin_arc_flag()
__builtin_arc_lr()
__builtin_arc_sleep()
__builtin_arc_sr()
__builtin_arc_swi()
</pre></div>

<hr>
<div class="header">
<p>
Next: <a href="ARC-SIMD-Built_002din-Functions.html#ARC-SIMD-Built_002din-Functions" accesskey="n" rel="next">ARC SIMD Built-in Functions</a>, Previous: <a href="Altera-Nios-II-Built_002din-Functions.html#Altera-Nios-II-Built_002din-Functions" accesskey="p" rel="prev">Altera Nios II Built-in Functions</a>, Up: <a href="Target-Builtins.html#Target-Builtins" accesskey="u" rel="up">Target Builtins</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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