<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/63571>63571</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [RISC-V][SiFive] `sifive_vector.h` doesn't work in C++?
        </td>
    </tr>

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

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

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

<pre>
    The same code for C works just fine: https://godbolt.org/z/T3WboYvT3 but fails for C++: https://godbolt.org/z/aKP38aTqd

```cpp
#include <sifive_vector.h>

#define p27_26 (0b11)
#define p11_7 (0b11111)

void test_sf_vc_xv_se_u64m1(vuint64m1_t vs2, uint64_t rs1, size_t vl) {
  __riscv_sf_vc_xv_se_u64m1(p27_26, p11_7, vs2, rs1, vl);
}
```

C++ failure:

```
<source>:7:3: error: use of undeclared identifier '__riscv_sf_vc_xv_se_u64m1'
    7 | __riscv_sf_vc_xv_se_u64m1(p27_26, p11_7, vs2, rs1, vl);
      |   ^
1 error generated.
Compiler returned: 1
```

(both compiled with `-march=rv64gcv_xsfvcp`)

Am I doing something wrong? Any advice would be welcome! :)
</pre>
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