<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/94116>94116</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [AMDGPU] v_pk_fmac_f16 is broken with inline constants on gfx11
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

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

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

<pre>
    I'm using LLVM version 398162ddbcf741c49e86bef2ef4aaa3fd0213916

I tested inline constant behavior of `v_pk_fma_f16` on Navi31 and Raphael. For gfx11 (and I assume all newer hardware), the fp16 inline constant is duplicated into the high bits. For gfx10.3 (and I assume all older hardware), the upper half always reads zero. LLVM seems to apply the gfx10 behavior for all generations.

Current llvm-mc assembler behavior for gfx11:
```
v_pk_fmac_f16 v0, 0x3C003C00, v1 // 0xff, 0x02, 0x00, 0x78, 0x00, 0x3c, 0x00, 0x3c
v_pk_fmac_f16 v0, 0x3C00, v1     // 0xf2, 0x02, 0x00, 0x78
```

Expected behavior according to my Navi31 tests:
```
v_pk_fmac_f16 v0, 0x3C003C00, v1 // 0xf2, 0x02, 0x00, 0x78
v_pk_fmac_f16 v0, 0x3C00, v1     // 0xff, 0x02, 0x00, 0x78, 0x00, 0x3c, 0x00, 0x00
```








</pre>
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