<html>
    <head>
      <base href="https://bugs.llvm.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - _mm_setzero_si64 violates the spec by generating xorps instead of pxor"
   href="https://bugs.llvm.org/show_bug.cgi?id=35869">35869</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>_mm_setzero_si64 violates the spec by generating xorps instead of pxor
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

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

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

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

        <tr>
          <th>Severity</th>
          <td>enhancement
          </td>
        </tr>

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

        <tr>
          <th>Component</th>
          <td>C++
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>gonzalobg88@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>dgregor@apple.com, llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>In the `<mmintrin.h>` header, the intrinsic `__mm_setzero_si64` [0] implemented
as follows:

static __inline__ __m64 __DEFAULT_FN_ATTRS
_mm_setzero_si64(void)
{
    return (__m64){ 0LL };
}

generates `xorps` [1] violating the spec [2] which says that it should generate
the instruction sequence `pxor mm, mm`.

[0]:
<a href="https://github.com/llvm-mirror/clang/blob/master/lib/Headers/mmintrin.h#L1296">https://github.com/llvm-mirror/clang/blob/master/lib/Headers/mmintrin.h#L1296</a>
[1]: <a href="https://godbolt.org/g/FnQYkf">https://godbolt.org/g/FnQYkf</a>
[2]:
<a href="https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_mm_setzero_si64&expand=4727,4727">https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_mm_setzero_si64&expand=4727,4727</a></pre>
        </div>
      </p>


      <hr>
      <span>You are receiving this mail because:</span>

      <ul>
          <li>You are on the CC list for the bug.</li>
      </ul>
    </body>
</html>