<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/56091>56091</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [AMDGPU][MC][GFX11] Disassembly of v_cmpx*_e64_dpp cannot be reassembled
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:AMDGPU,
            mc
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
            dpreobra
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          dpreobra
      </td>
    </tr>
</table>

<pre>
    `e64_dpp` variants `v_cmp_*` and `v_cmpx_*` opcodes have different suffices when disassembled.
The following code

    0x05,0x00,0x7d,0xd4,0xfa,0x04,0x02,0x00,0x01,0x6f,0x01,0xff
    0x00,0x00,0xfd,0xd4,0xfa,0x04,0x02,0x00,0x01,0x6f,0x01,0xff

is disassembled as follows:

    v_cmp_class_f16_e64_dpp     s5, v1, v2 row_xmask:15 row_mask:0xf bank_mask:0xf
    v_cmpx_class_f16_e64        v1, v2 row_xmask:15 row_mask:0xf bank_mask:0xf

This may look like a cosmetic issue, but only the first opcode can be reassembled, the second triggers an error.

</pre>
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