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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 - AArch64 inline asm does not recognise Q registers in clobber list"
   href="https://bugs.llvm.org/show_bug.cgi?id=50750">50750</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>AArch64 inline asm does not recognise Q registers in clobber list
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libraries
          </td>
        </tr>

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

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

        <tr>
          <th>OS</th>
          <td>Linux
          </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>Backend: AArch64
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>david.spickett@linaro.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>arnaud.degrandmaison@arm.com, llvm-bugs@lists.llvm.org, smithp352@googlemail.com, Ties.Stuij@arm.com
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Compiling the following for AArch64:
void foo(void) {
    __asm __volatile("" : : : "v0");
    __asm __volatile("" : : : "q0");
}

Produces this error:
<source>:3:31: error: unknown register name 'q0' in asm
    __asm __volatile("" : : : "q0");
                              ^

The same example does not error with GCC.

<a href="https://godbolt.org/z/zMdqP9qdo">https://godbolt.org/z/zMdqP9qdo</a>

Using "v0" instead works and has the same effect but we should recognise the
other naming schemes.

<a href="https://developer.arm.com/documentation/den0024/a/ARMv8-Registers/NEON-and-floating-point-registers/Scalar-register-sizes">https://developer.arm.com/documentation/den0024/a/ARMv8-Registers/NEON-and-floating-point-registers/Scalar-register-sizes</a>

Clang does not recognise "h", "b" or "q" where GCC does.</pre>
        </div>
      </p>


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