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      <base href="https://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 --- - unsigned integer overflow in murmur2_or_cityhash<_Size, 64>::__hash_len_17_to_32"
   href="https://llvm.org/bugs/show_bug.cgi?id=31131">31131</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>unsigned integer overflow in murmur2_or_cityhash<_Size, 64>::__hash_len_17_to_32
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libc++
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>unspecified
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>All
          </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>All Bugs
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>gonzalobg88@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org, mclow.lists@gmail.com
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>I am hitting a 

include/c++/v1/memory:3139:46: runtime error: unsigned integer overflow:
8751185004910830951 * 13011662864482103923 cannot be represented in type
'unsigned long'
SUMMARY: AddressSanitizer: undefined-behavior include/c++/v1/memory:3139:46 in 

The function seems to be: 

__murmur2_or_cityhash<_Size, 64>::__hash_len_17_to_32(const char *__s, _Size
__len).


Since it is a hash function, I would guess that the unsigned integer overflow
is intentional, and the signature is missing the:

_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK

annotation.</pre>
        </div>
      </p>
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