title: _BitScanForward64 using MinGW on Windows
body: <p>I am trying to use _BitScanForward64 intrinsic (<a href="https://software.intel.com/sites/landingpage/IntrinsicsGuide/#expand=381,421,373&amp;cats=Bit%20Manipulation" rel="nofollow">https://software.intel.com/sites/landingpage/IntrinsicsGuide/#expand=381,421,373&amp;cats=Bit%20Manipulation</a>) using MinGW 64 on Windows (GCC 4.8.1).</p>
  
  <p>I tried:</p>
  
  <pre><code>#include "immintrin.h"
  #include "x86intrin.h"
  #include "xmmintrin.h"
  </code></pre>
  
  <p>but it still doesn't see the function (according to Intel guide it should be in "immintrin.h").</p>
  
  <p>How do I get it to work using MinGW64 on Windows?</p>