ctlz = most signficant bits, cttz = least sig

llvm-svn: 22061

Author: lattner

llvm/docs/LangRef.html

@@ -149,8 +149,8 @@
       <li><a href="#int_count">Bit counting Intrinsics</a>
         <ol>
           <li><a href="#int_ctpop">'<tt>llvm.ctpop</tt>' Intrinsic </a></li>
-          <li><a href="#int_cttz">'<tt>llvm.cttz</tt>' Intrinsic </a></li>
           <li><a href="#int_ctlz">'<tt>llvm.ctlz</tt>' Intrinsic </a></li>
+          <li><a href="#int_cttz">'<tt>llvm.cttz</tt>' Intrinsic </a></li>
         </ol>
       </li>
       <li><a href="#int_debugger">Debugger intrinsics</a></li>
@@ -3205,74 +3205,77 @@ <h5>Semantics:</h5>
 
 <!-- _______________________________________________________________________ -->
 <div class="doc_subsubsection">
-  <a name="int_cttz">'<tt>llvm.cttz</tt>' Intrinsic</a>
+  <a name="int_ctlz">'<tt>llvm.ctlz</tt>' Intrinsic</a>
 </div>
 
 <div class="doc_text">
 
 <h5>Syntax:</h5>
 <pre>
-  declare int %llvm.cttz(int &lt;src&gt;)
+  declare int %llvm.ctlz(int &lt;src&gt;)
 
 </pre>
 
 <h5>Overview:</h5>
 
 <p>
-The '<tt>llvm.cttz</tt>' intrinsic counts the number of trailing zeros.
+The '<tt>llvm.ctlz</tt>' intrinsic counts the number of leading zeros in a
+variable.
 </p>
 
 <h5>Arguments:</h5>
 
 <p>
 The only argument is the value to be counted.  The argument may be of any
-integer type.  The return type must match the argument type.
+integer type. The return type must match the argument type.
 </p>
 
 <h5>Semantics:</h5>
 
 <p>
-The '<tt>llvm.cttz</tt>' intrinsic counts the trailing zeros in a variable.  If
-the src == 0 then the result is the size in bits of the type of src.
+The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
+in a variable.  If the src == 0 then the result is the size in bits of the type
+of src. For example, <tt>llvm.cttz(int 2) = 30</tt>.
 </p>
 </div>
 
+
+
 <!-- _______________________________________________________________________ -->
 <div class="doc_subsubsection">
-  <a name="int_ctlz">'<tt>llvm.ctlz</tt>' Intrinsic</a>
+  <a name="int_cttz">'<tt>llvm.cttz</tt>' Intrinsic</a>
 </div>
 
 <div class="doc_text">
 
 <h5>Syntax:</h5>
 <pre>
-  declare int %llvm.ctlz(int &lt;src&gt;)
+  declare int %llvm.cttz(int &lt;src&gt;)
 
 </pre>
 
 <h5>Overview:</h5>
 
 <p>
-The '<tt>llvm.ctlz</tt>' intrinsic counts the number of leading zeros in a
-variable.
+The '<tt>llvm.cttz</tt>' intrinsic counts the number of trailing zeros.
 </p>
 
 <h5>Arguments:</h5>
 
 <p>
 The only argument is the value to be counted.  The argument may be of any
-integer type. The return type must match the argument type.
+integer type.  The return type must match the argument type.
 </p>
 
 <h5>Semantics:</h5>
 
 <p>
-The '<tt>llvm.ctlz</tt>' intrinsic counts the leading zeros in a variable.  If
-the src == 0 then the result is the size in bits of the type of src.
+The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
+in a variable.  If the src == 0 then the result is the size in bits of the type
+of src.  For example, <tt>llvm.cttz(2) = 1</tt>.
 </p>
 </div>
 
-
 <!-- ======================================================================= -->
 <div class="doc_subsection">
   <a name="int_debugger">Debugger Intrinsics</a>