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Added initial design for the llvm.readio and llvm.writeio intrinsics. 

llvm-svn: 12864
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John Criswell 2004-04-12 15:02:16 +00:00
parent a2b279e89c
commit a450122ebf
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llvm/docs/LangRef.html
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@ -107,6 +107,8 @@
<ol>
<li><a href="#i_readport">'<tt>llvm.readport</tt>' Intrinsic</a></li>
<li><a href="#i_writeport">'<tt>llvm.writeport</tt>' Intrinsic</a></li>
<li><a href="#i_readio">'<tt>llvm.readio</tt>' Intrinsic</a></li>
<li><a href="#i_writeio">'<tt>llvm.writeio</tt>' Intrinsic</a></li>
</ol>
<li><a href="#int_libc">Standard C Library Intrinsics</a>
<ol>
@ -2013,6 +2015,7 @@ operating system level code.
</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="i_readport">'<tt>llvm.readport</tt>' Intrinsic</a>
@ -2095,6 +2098,99 @@ value written must be 8, 16, or 32 bits in length.
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="i_readio">'<tt>llvm.readio</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
<pre>
call &lt;integer type&gt; (&lt;integer type&gt;)* %llvm.readio (&lt;integer type&gt; &lt;address&gt;)
</pre>
<h5>Overview:</h5>
<p>
The '<tt>llvm.readio</tt>' intrinsic reads data from a memory mapped I/O
address.
</p>
<h5>Arguments:</h5>
<p>
The argument to this intrinsic indicates the memory address from which to read
the data.
</p>
<h5>Semantics:</h5>
<p>
The '<tt>llvm.readio</tt>' intrinsic reads data from a memory mapped I/O
location specified by <i>address</i> and returns the value. The address and
return value must be integers, but the size allowed for each is dependent upon
the platform upon which the program is code generated.
</p>
<p>
This intrinsic ensures that the I/O data read occurs in instruction order in
relation to other I/O data reads and writes (as opposed to a normal load, where
hardware scheduling can re-arrange the actual memory accesses to occur out of
order).
</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="i_writeio">'<tt>llvm.writeio</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
<pre>
call void (&lt;integer type&gt;, &lt;integer type&gt;)* %llvm.writeio (&lt;integer type&gt; &lt;value&gt;, &lt;integer type&gt; &lt;address&gt;)
</pre>
<h5>Overview:</h5>
<p>
The '<tt>llvm.writeio</tt>' intrinsic writes data to the specified memory
mapped I/O address.
</p>
<h5>Arguments:</h5>
<p>
The first argument to this intrinsic indicates the memory address to which data
should be written.
</p>
<p>
The second argument is the value to write to the memory mapped I/O location.
</p>
<h5>Semantics:</h5>
<p>
The '<tt>llvm.writeio</tt>' intrinsic writes <i>value</i> to the memory mapped
I/O address specified by <i>address</i>. The address and value must be
integers, but the size is dependent upon the platform upon which the program is
code generated.
</p>
<p>
This intrinsic ensures that the I/O data write occurs in instruction order in
relation to other I/O data reads and writes (as opposed to a normal store,
where hardware scheduling can re-arrange the actual memory accesses to occur
out of order).
</p>
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="int_libc">Standard C Library Intrinsics</a>