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    <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 - NewGVN should account for switch statements with multiple edges to themselves"
   href="https://bugs.llvm.org/show_bug.cgi?id=33184">33184</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>NewGVN should account for switch statements with multiple edges to themselves
          </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>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>Scalar Optimizations
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>davide@freebsd.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>dberlin@dberlin.org, llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>If switch statements with multiple edges to itself are allowed, then the
current ordering might not work.

Quoting from <a href="https://reviews.llvm.org/D24805">https://reviews.llvm.org/D24805</a>

"""
Do we allow switch statements with multiple edges to ourself?

ie

bb1:

switch <whatever> [
i32 0 : label bb1
i32 1: label bb1 ]


(which, after propagation,  could cause a phi with different operands and the
same incoming blocks)
If so, either we need stable sorts, or a better ordering of incoming blocks,
because the pointer equality we use will not definitely sort them into a
consistent order
"""</pre>
        </div>
      </p>


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