<ol>
<li><a href="#i_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
<li><a href="#i_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
+ </ol>
+ </li>
+ <li><a href="#int_os">Operating System Intrinsics</a>
+ <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>
</ol>
- </li>
<li><a href="#int_libc">Standard C Library Intrinsics</a>
<ol>
<li><a href="#i_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a></li>
</p>
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_os">Operating System Intrinsics</a>
+</div>
+
+<div class="doc_text">
+<p>
+These intrinsics are provided by LLVM to support the implementation of
+operating system level code.
+</p>
+
+</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
<a name="i_readport">'<tt>llvm.readport</tt>' Intrinsic</a>
<h5>Syntax:</h5>
<pre>
- call sbyte (ushort address)* %llvm.readport(ushort <address>)
- call ubyte (ushort address)* %llvm.readport(ushort <address>)
- call short (ushort address)* %llvm.readport(ushort <address>)
- call ushort (ushort address)* %llvm.readport(ushort <address>)
- call int (ushort address)* %llvm.readport(ushort <address>)
- call uint (ushort address)* %llvm.readport(ushort <address>)
+ call <integer type> (<integer type>)* %llvm.readport (<integer type> <address>)
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>llvm.readport</tt>' intrinsic reads data from the specified I/O port.
+The '<tt>llvm.readport</tt>' intrinsic reads data from the specified hardware
+I/O port.
</p>
<h5>Arguments:</h5>
<p>
-The argument to this intrinsic indicates the I/O address from which to read
-the data. The address is in the I/O address namespace; it is not a memory
-location.
+The argument to this intrinsic indicates the hardware I/O address from which
+to read the data. The address is in the hardware I/O address namespace (as
+opposed to being a memory location for memory mapped I/O).
</p>
<h5>Semantics:</h5>
<p>
-The '<tt>llvm.readport</tt>' intrinsic reads data from the I/O port specified
-by <i>address</i> and returns the value. The address and return value must
-be integers, but the size is dependent upon the platform upon which the
-program is code generated. For example, on x86, the address must be a
-ushort, and the return value must be 8, 16, or 32 bits.
+The '<tt>llvm.readport</tt>' intrinsic reads data from the hardware I/O port
+specified by <i>address</i> and returns the value. The address and return
+value must be integers, but the size is dependent upon the platform upon which
+the program is code generated. For example, on x86, the address must be an
+unsigned 16 bit value, and the return value must be 8, 16, or 32 bits.
</p>
</div>
<h5>Syntax:</h5>
<pre>
- call void (ushort address, sbyte value)* %llvm.writeport(ushort <address>, sbyte <value>)
- call void (ushort address, ubyte value)* %llvm.writeport(ushort <address>, ubyte <value>)
- call void (ushort address, short value)* %llvm.writeport(ushort <address>, short <value>)
- call void (ushort address, ushort value)* %llvm.writeport(ushort <address>, ushort <value>)
- call void (ushort address, int value)* %llvm.writeport(ushort <address>, int <value>)
- call void (ushort address, uint value)* %llvm.writeport(ushort <address>, uint <value>)
+ call void (<integer type>, <integer type>)* %llvm.writeport (<integer type> <value>, <integer type> <address>)
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>llvm.writeport</tt>' intrinsic writes data to the specified I/O port.
+The '<tt>llvm.writeport</tt>' intrinsic writes data to the specified hardware
+I/O port.
</p>
<h5>Arguments:</h5>
<p>
-The first argument to this intrinsic indicates the I/O address to which data
-should be written. The address is in the I/O address namespace; it is not a
-memory location.
+The first argument to this intrinsic indicates the hardware I/O address to
+which data should be written. The address is in the hardware I/O address
+namespace (as opposed to being a memory location for memory mapped I/O).
</p>
<p>
The '<tt>llvm.writeport</tt>' intrinsic writes <i>value</i> to the I/O port
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.
-For example, on x86, the address must be a ushort, and the value written must
-be 8, 16, or 32 bits in length.
+For example, on x86, the address must be an unsigned 16 bit value, and the
+value written must be 8, 16, or 32 bits in length.
</p>
</div>