<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/62381>62381</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [OpenMP] SIMD directive is prescriptive, but vectorizer fails
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            openmp,
            clang:codegen
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
            alexey-bataev
      </td>
    </tr>

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

<pre>
    With loop dependencies, the vectorizer fails to vectorize a loop, although OpenMP SIMD is prescriptive.

Example code:
https://github.com/LLNL/dataracebench/blob/master/micro-benchmarks/DRB024-simdtruedep-orig-yes.c

Compilation results in:
```
warning: loop not vectorized: the optimizer was unable to perform the requested transformation; the transformation might be disabled or specified as part of an unsupported transformation ordering [-Wpass-failed=transform-warning]
#pragma omp simd
```
And code that is not vectorized.
</pre>
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