title: Can/should libiomp5 and libgomp mix?
body: <p>We are compiling an application that uses OpenMP.  We are using gcc 4.4, with -fopenmp.  The app also uses IPP, which includes its own version of OpenMP (libiomp5).  (Note: we are disabling IPP's internal threading by calling ippSetNumThread(1).  According to Intel's documentation, this should avoid conflicts with other threading libraries.  However, linking with IPP still links in libiomp5.so.)</p>
  
  <p>Since libiomp5.so is already linked in, we have <em>not</em> been linking with libgomp.so (gcc's version of OpenMP).  For a long time this has worked, but after a seemingly inconsequential change we started seeing very odd OpenMP-related crashes on one of four platforms we support (the other three platforms still work fine).  </p>
  
  <p>I can make the crashes go away if I link in libgomp.so as well as libiomp5.so.</p>
  
  <p>I have a couple questions about this:</p>
  
  <ol>
  <li>Is linking with both these libraries safe?  It seems like they would both define the same symbols.</li>
  <li>Is there a way to tell what version of OpenMP libiomp5.so supports?  With gcc 4.4, libgomp.so should be at OpenMP v3.0.  I can't find any information in Intel's documentation about the OpenMP version of libiomp5.so.  </li>
  </ol>