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      <base href="http://llvm.org/bugs/" />
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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 --- - A very small test resulting in extremely long compilation in "clang -O2" version 3.5, trunk 199677"
   href="http://llvm.org/bugs/show_bug.cgi?id=18606">18606</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>A very small test resulting in extremely long compilation in "clang  -O2" version 3.5, trunk 199677
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>tools
          </td>
        </tr>

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

        <tr>
          <th>Hardware</th>
          <td>Macintosh
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>MacOS X
          </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>opt
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>mohammad.r.haghighat@intel.com
          </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>Created <span class=""><a href="attachment.cgi?id=11934" name="attach_11934" title="Sources of t27056 test including its source, input, and outputs">attachment 11934</a> <a href="attachment.cgi?id=11934&action=edit" title="Sources of t27056 test including its source, input, and outputs">[details]</a></span>
Sources of t27056 test including its source, input, and outputs

This is one of the tests generated by icFuzz in the attachment of comment
<a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - [icFuzz] Incorrect results at -O2 optimization and infinite loop in the Clang optimizer"
   href="show_bug.cgi?id=16431#c30">http://llvm.org/bugs/show_bug.cgi?id=16431#c30</a>

the test resuls in an extremely long compilation in clang version 3.5, trunk
199677. Clang -O2 compilation seems to run until it goes out of memory. The
core of the test is very simple:

    for (kj = 1; kj < 2; ++kj) {
        for (jd = 1; jd < 32; ++jd) {
            zz *= zz;
        }
    }

I guess the problem is a result of unrolling and creating a sequence of
statements that result in analysis nodes that have exponential complexity. If
the 2nd loop upper bound (32) is changed to a larger number (e.g., 132) or a
much smaller number (e.g., 12), compilation terminates fast.</pre>
        </div>
      </p>
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