<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/126227>126227</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [ARM] Invalid invalid fixed-point conversion instructions accepted by assembler
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:ARM,
            accepts-invalid,
            mc
      </td>
    </tr>

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

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

<pre>
    These instructions are invalid because the two register operands must be the same, but they are accepted by the LLVM assembler. Both ARM and Thumb ISAs are affected.

```
  .arm
  vcvt.u32.f32 s0, s1, #1
  vcvt.u32.f64 d3, d4, #1
  .thumb
  vcvt.u32.f32 s0, s1, #1
  vcvt.u32.f64 d3, d4, #1
```

```
$ /work/llvm/build/bin/llvm-mc -triple armv8a < fixed-point.s
        .code   32
        .p2align        2
 vcvt.u32.f32    s0, s0, #1
        vcvt.u32.f64    d3, d3, #1
        .code 16
        .p2align        1
        vcvt.u32.f32    s0, s0, #1
 vcvt.u32.f64    d3, d3, #1
```
</pre>
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