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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 --- - Second argument to signed Neon vtbl functions should be unsigned"
   href="https://llvm.org/bugs/show_bug.cgi?id=23324">23324</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Second argument to signed Neon vtbl functions should be unsigned
          </td>
        </tr>

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

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

        <tr>
          <th>Component</th>
          <td>Headers
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>lennox@cs.columbia.edu
          </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>The ARM C Language Extensions document (ACLE) specifies that the second (index)
parameter to the vtbl and vtbx family of functions should be unsigned, even
when the other parameters are signed:

Aarch32:
T vtblN_ST(TxN a, UT b);
T vtbxN_ST(T a, TxN b, UT c);

Aarch64:
T vqtblNQ_ST (T2xN t, UT idx);
T vqtbxNQ_ST (T a, T2xN t, UT idx);

E.g., 
int8x8_t vqtbl1_s8 (int8x16_t a, uint8x8_t b)

Clang declares them to be signed, instead.

GCC has had these correct for Aarch64 since GCC 4.9, though for ARM (Aarch32)
it still has the second value signed.</pre>
        </div>
      </p>
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