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    <head>
      <base href="http://llvm.org/bugs/" />
    </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 --- - [Vectorizer] Implement interleaved stride vectorization"
   href="http://llvm.org/bugs/show_bug.cgi?id=17679">17679</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[Vectorizer] Implement interleaved stride vectorization
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libraries
          </td>
        </tr>

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

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

        <tr>
          <th>Reporter</th>
          <td>renato.golin@linaro.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>After implementing the non-interleaved vectorization, detect interleaved
patterns, such as:

for (i..N/3) {
 a[3*i] = b[3*i] + I;
 a[3*i+1] = b[3*i+1] + J;
 a[3*i+2] = b[3*i+2] + K;
}

Where you can unroll this into:

for (i..N/3) {
 a[3*i] = b[3*i] + I;
 a[3*i+3] = b[3*i+3] + I;
 a[3*i+6] = b[3*i+6] + I;
 a[3*i+9] = b[3*i+9] + I;

 a[3*i+1] = b[3*i+1] + J;
 a[3*i+4] = b[3*i+4] + J;
 a[3*i+7] = b[3*i+7] + J;
 a[3*i+10] = b[3*i+10] + J;

 a[3*i+2] = b[3*i+2] + K;
 a[3*i+5] = b[3*i+5] + K;
 a[3*i+8] = b[3*i+8] + K;
 a[3*i+11] = b[3*i+11] + K;
}

And use interleaved reads/writes, for example ARM's VLDN/VSTN.</pre>
        </div>
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