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      <base href="https://bugs.llvm.org/">
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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 - memcmp with constant string arguments produces wrong result"
   href="https://bugs.llvm.org/show_bug.cgi?id=40063">40063</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>memcmp with constant string arguments produces wrong result
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>6.0
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>FreeBSD
          </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>LLVM Codegen
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>bruno@clisp.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=21244" name="attach_21244" title="Test case">attachment 21244</a> <a href="attachment.cgi?id=21244&action=edit" title="Test case">[details]</a></span>
Test case

A memcmp() call with constant arguments is apparently inlined by clang and
produces a wrong result.

How to reproduce:
$ cc foo.c
$ nm a.out | grep memcmp
$ ./a.out
Expected output: A negative number.
Actual output: 1

OS: FreeBSD 12.0 on x86_64

clang version:
$ cc --version
FreeBSD clang version 6.0.1 (tags/RELEASE_601/final 335540) (based on LLVM
6.0.1)
Target: x86_64-unknown-freebsd12.0
Thread model: posix
InstalledDir: /usr/bin</pre>
        </div>
      </p>


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