<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/137188>137188</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [DirectX] Legalize memcpy
        </td>
    </tr>

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

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

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

<pre>
    ## Problem 
Currently we are emitting memcpys both 64bit and 32bit versions
The DML shaders will have errors like so:

`error: Unsupported intrinsic llvm.memcpy.p3.p3.i32 for DXIL lowering`

We emit this error because the memcpy intrinsic is not valid DXIL.

These memcpys tend to be in the `hlsl_groupshared` ie `addressspace(3)`. This might make the memcpy more involved to serialize into a set of store calls.

## Example

```llvm
tail call void @llvm.memcpy.p3.p3.i32(ptr addrspace(3) align 4 %scevgep, ptr addrspace(3) align 4 %scevgep19, i32 %38, i1 false)
```
</pre>
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