<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/129003>129003</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [HLSL] reflect, distance, and length intrinsics are not restricting vector size
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            HLSL
      </td>
    </tr>

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

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

<pre>
    https://github.com/llvm/llvm-project/blob/556eb8244201a81fff7b246561a677a782b69fa0/clang/lib/Headers/hlsl/hlsl_intrinsics.h#L2084-L2093

https://github.com/llvm/llvm-project/blob/556eb8244201a81fff7b246561a677a782b69fa0/clang/lib/Headers/hlsl/hlsl_intrinsics.h#L1446-L1454

https://github.com/llvm/llvm-project/blob/556eb8244201a81fff7b246561a677a782b69fa0/clang/lib/Headers/hlsl/hlsl_intrinsics.h#L933-L942

The fix:
we need to exclude vec1s and limit to vec4. the apis should be updated like so:
```hlsl
template <int N, typename = std::enable_if_t<(N > 1 && N <=4)>>
const inline vector<float, N> reflect(vector<float, N> X, vector<float, N> Y) {
  return __detail::reflect_vec_impl(X, Y);
}
```

Long term we will want to support long vectors we may want to do those like so
```hlsl
_HLSL_AVAILABILITY(shadermodel, 6.9)
template <int N, typename = std::enable_if_t<(N >4)>>
const inline vector<float, N> reflect(vector<float, N> X, vector<float, N> Y) {
     return __detail::fmod_vec_impl(X, Y);
}
```
For this ticket though we will only restrict the vector range.
</pre>
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