<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/64980>64980</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [asm] the embedded assemble prevent the optimization of clang
        </td>
    </tr>

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

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

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

<pre>
    test: https://gcc.godbolt.org/z/s9qWz8hs3
```
int test_inline_asm(int &a, int &b, int &c, int &d, int e) {
    int a0 = a, b0 = b;
    __asm__ __volatile__("");
    a = a0, b = b0;
    return 0;
}
```

* **gcc**: return 0 directly
```
        mov w0, 0
        ret
```
* **clang**: the **__asm__ __volatile__** block the value propagation
```
        ldr     w8, [x0]
        ldr w9, [x1]
        str     w8, [x0]
        mov     w0, wzr
 str     w9, [x1]
        ret
```
</pre>
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