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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 - [Windows][AArch64] Returning structures from functions has wrong ABI"
   href="https://bugs.llvm.org/show_bug.cgi?id=47836">47836</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[Windows][AArch64] Returning structures from functions has wrong ABI
          </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>Windows NT
          </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>C++
          </td>
        </tr>

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

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

        <tr>
          <th>CC</th>
          <td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=24056" name="attach_24056" title="source files to reproduce">attachment 24056</a> <a href="attachment.cgi?id=24056&action=edit" title="source files to reproduce">[details]</a></span>
source files to reproduce

Clang++ has an incorrect ABI for Windows ARM64.  When returning a non-POD type
from a function in Windows, the function is expected to return the hidden
destination pointer in X0.  This will crash in certain scenarios when MSVC
compiles some translation units and Clang++ others.

This is equivalent to the following existing bug, but for ARM64 instead of
x86/x86-64.  I have not checked ARM32 Windows.
<a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [Windows] Returning structures from functions has wrong ABI"
   href="show_bug.cgi?id=15556">https://bugs.llvm.org/show_bug.cgi?id=15556</a>

clang-cl --target=arm64-pc-windows-msvc /c /MT /GS vectorbug-clang-side.cpp
cl /c /MT /GS vectorbug-msvc-side.cpp
link /DEBUG /OUT:vectorbug.exe vectorbug-msvc-side.obj vectorbug-clang-side.obj
libcmt.lib kernel32.lib</pre>
        </div>
      </p>


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