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    <head>
      <base href="https://llvm.org/bugs/" />
    </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 --- - UBSan detects signed integer overflow for multiplication of uint16_t"
   href="https://llvm.org/bugs/show_bug.cgi?id=25580">25580</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>UBSan detects signed integer overflow for multiplication of uint16_t
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>new-bugs
          </td>
        </tr>

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

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

        <tr>
          <th>Component</th>
          <td>new bugs
          </td>
        </tr>

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

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

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=15317" name="attach_15317" title="simple test case demonstrating the failure">attachment 15317</a> <a href="attachment.cgi?id=15317&action=edit" title="simple test case demonstrating the failure">[details]</a></span>
simple test case demonstrating the failure

First seen as a failing test for the SaturatingMultiply() function template
added in r253497.

Test case attached.

$ clang++ -O1 -std=c++11 -fsanitize=undefined test.cpp -o test
$ ./test
main.cpp:25:11: runtime error: signed integer overflow: 65535 * 65535 cannot be
represented in type 'int'

Interestingly, the failure only occurs with uint16_t.
The other unsigned types (uint8_t/uint32_t/uint64_t) pass if I comment out the
uint16_t case.


The issue reproduces at least with clang 3.6 on Ubuntu 15.10 x86_64 as well as
trunk Mac OS X 10.11.1 / Xcode 7.1.</pre>
        </div>
      </p>
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