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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 - llc -O1 results in "Unanalyzed node not noticed?", "UNREACHABLE executed at ../lib/CodeGen/SelectionDAG/LegalizeTypes.cpp:482!""
   href="https://bugs.llvm.org/show_bug.cgi?id=49393">49393</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>llc -O1 results in "Unanalyzed node not noticed?", "UNREACHABLE executed at ../lib/CodeGen/SelectionDAG/LegalizeTypes.cpp:482!"
          </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>enhancement
          </td>
        </tr>

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

        <tr>
          <th>Component</th>
          <td>Common Code Generator Code
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>mikael.holmen@ericsson.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=24581" name="attach_24581" title="bbi-53378_x86.ll reproducer">attachment 24581</a> <a href="attachment.cgi?id=24581&action=edit" title="bbi-53378_x86.ll reproducer">[details]</a></span>
bbi-53378_x86.ll reproducer

llvm commit: 4444b343d7e
Reproduce with:
 llc -O1 -o - bbi-53378_x86.ll

Result:
 Unanalyzed node not noticed?
 t25: i16 = fp_to_sint t43

 UNREACHABLE executed at ../lib/CodeGen/SelectionDAG/LegalizeTypes.cpp:482!

This seems to start happening with 960cbc53ca:

    [DAGCombine] Remove dead node when it is created by getNegatedExpression

    We hit the compiling time reported by
<a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - Compile-time explosion in DAGCombiner::Run"
   href="show_bug.cgi?id=46877">https://bugs.llvm.org/show_bug.cgi?id=46877</a>
    and the reason is the same as D77319. So we need to remove the dead node we
created
    to avoid increase the problem size of DAGCombiner.

    Reviewed By: Spatel

    Differential Revision: <a href="https://reviews.llvm.org/D86183">https://reviews.llvm.org/D86183</a></pre>
        </div>
      </p>


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