<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/88949>88949</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [SPIRV][HLSL] implement `rsqrt` lowering
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:DirectX,
            HLSL
      </td>
    </tr>

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

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

<pre>
    ```hlsl
rsqrt(a);
```
in spirv should emit
```asm 
`%13 = OpExtInst %v4float %1 InverseSqrt %12` 
```
https://shader-playground.timjones.io/46053c341c6033c8b69a6984ec20d67a

should also update the hlsl intrinsic tests.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJxsUt1u3CwQfZrxDYoFw8_aF75IPn-rRorUqpGq3mJgbVJsHMDbpk9frXeVqlUlBMzRMIczc3TOflyc60A-gOwrvZUppu6k08-4hGqI9q0DRa9rCjkA7YHep_yaCmCjAVvgD1fwPe8a-oXk1aczyVPcgiVu9uWvRJ1n8htCyTgB3pOP6_8_yuOSCwGUZ3EKUe9XRh6Xs0vZPb-mK4CgKPkn-1TKmoHfAx4Bj3nS1qW7Nei3McVtsXXx80tcXK59BDwKRSU3XDCjKOemGVSrVdsIZ5BaddA3in2_ydEhR7KtVhdHyuTIpTnELyX5JXtDissl15XtuG15qyvXsQPj2NKDVNXUnZhhVpnmJE6sbThaa6hlXBpHGRduqHyHFAUVTLGGSilqPCjr2kELwQYcGgqCuln7UIdwnuuYxsrnvLmuaVrRVkEPLuR9qoiDNt_cYoHf9z45U74CIuB_gPjh6fnpEsi-St2l0N2wjRkEDf7y_ffSxZewe-T50-PnLyB7kA_7W9kTP6_BzW4pBBS9GkNREuJ3l_wyVlsK3Z_DGH2ZtqE2cQY8Xihux92a4oszBfC4S8mAx13NrwAAAP__u3XJ5Q">