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      <base href="https://llvm.org/bugs/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - clang -fopenmp -ffast-math causes compile failures with gnu math.h"
   href="https://llvm.org/bugs/show_bug.cgi?id=28973">28973</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>clang -fopenmp -ffast-math causes compile failures with gnu math.h
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>3.7
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>-New Bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>dan_gulotta@yahoo.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>When OpenMP is enabled in Clang, the _OPENMP macro is set to 201307, indicating
support for OpenMP 4.  Defining the _OPENMP macro this way will cause some
header files to try to use OpenMP 4 features not yet supported by Clang.  In
particular, GNU's bits/math-vector.h will use "omp declare simd notinbranch"
when __FAST_MATH__ is defined and _OPENMP >= 201307, leading to compile errors.
 Manually defining _OPENMP to be 201107 makes the problem go away.</pre>
        </div>
      </p>
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          <li>You are on the CC list for the bug.</li>
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