<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/65629>65629</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [AMDGPU] The `__builtin_round` intrinsic does not preserve `-0.0`
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:AMDGPU,
            new issue
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          jhuber6
      </td>
    </tr>
</table>

<pre>
    The standard states the following about the behavior of the `round` functoin:
> If the implementation supports IEEE floating-point arithmetic (IEC 60559), for the std::round function: 
>   * If num is ±0, it is returned, unmodified 

This is currently not respected by the AMDGPU implementation of `__builtin_round`. See the following reproducer for an example.
```c
#include <assert.h>
#include <math.h>
#include <stdio.h>

int main() {
  double r;
  double in = -0.0;
#pragma omp target map(from : r)
  { r = __builtin_round(in); }
  assert(signbit(r) && "Result is no longer negative");
}
```
```shell
$ clang round.c -fopenmp --offload-arch=gfx1030 -fopenmp-offload-mandatory
$ ./a.out
a.out: round.c:10: int main(): Assertion `signbit(r) && "Result is no longer negative"' failed.
[1]    316479 IOT instruction (core dumped)  ./a.out

$ clang round.c -fopenmp --offload-arch=sm_89 -fopenmp-offload-mandatory
$ ./a.out
```
</pre>
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