title: icc: including omp.h requires byteswap.h
body: <p>Just tried to compile my code (which works perfectly fine with gcc) using icc-11.<br>
  If I include <code>omp.h</code> I get the following error:</p>
  
  <pre><code>/usr/include/bits/byteswap.h(47): error: identifier "__builtin_bswap32" is undefined
      return __builtin_bswap32 (__bsx);
             ^
  
  /usr/include/bits/byteswap.h(111): error: identifier "__builtin_bswap64" is undefined
      return __builtin_bswap64 (__bsx);
  </code></pre>
  
  <p>The same happens if I include <code>stdlib.h</code>.</p>
  
  <p>I'm really confused and I don't even know what byteswap is good for. I've issued the <code>iccvars_intel64.sh</code> script before compiling. Doesn't help much though.</p>
  
  <p>Any ideas?</p>
  
  <p>P.S.: Do I even need to include <code>omp.h</code> if want to parallelize some loops? Maybe I could simply omit <code>#include &lt;omp.h&gt;</code>.</p>