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      <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 - InstCombine infinite loop"
   href="https://bugs.llvm.org/show_bug.cgi?id=46271">46271</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>InstCombine infinite loop
          </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>Windows NT
          </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>Scalar Optimizations
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>craig.topper@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>This sequence causes instcombine to run in an infinite loop. It never even its
the max iteration check because we're always adding nodes to the worklist.


define i8 @foo(<2 x i8> %updatedret.i.i.i213) {
  %a = icmp sgt <2 x i8> %updatedret.i.i.i213, <i8 -1, i8 -1>
  %b = select <2 x i1> %a, <2 x i8> %updatedret.i.i.i213, <2 x i8> <i8 undef,
i8 -1>
  %resultvec.i = xor <2 x i8> %b, <i8 undef, i8 -1>
  %storeval.i.1.i = extractelement <2 x i8> %resultvec.i, i32 1
  ret i8 %storeval.i.1.i
}


Extract from <a href="https://github.com/ispc/ispc/issues/1788">https://github.com/ispc/ispc/issues/1788</a>  hopefully this is the
same issue there, but I"m not sure because the full IR hit the max iteration
limit.</pre>
        </div>
      </p>


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