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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - cbrt() function cannot be vectorized through OpenMP"
href="https://bugs.llvm.org/show_bug.cgi?id=36518">36518</a>
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<th>Summary</th>
<td>cbrt() function cannot be vectorized through OpenMP
</td>
</tr>
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<th>Product</th>
<td>OpenMP
</td>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>FreeBSD
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>Clang Compiler Support
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>jmd@freebsd.org
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=19962" name="attach_19962" title="reproduction of issue">attachment 19962</a> <a href="attachment.cgi?id=19962&action=edit" title="reproduction of issue">[details]</a></span>
reproduction of issue
A trivial loop using cbrt() from cmath in its body cannot be vectorized.
Compiling attached gives the following (on FreeBSD with LLVM devel as of
beginning of February):
$ clang++-devel -O3 -Rpass=loop-vectorize -Rpass-missed=loop-vectorize
-Rpass-analysis=loop-vectorize -fsave-optimization-record -fopenmp -o cbrt
cbrt.cpp
cbrt.cpp:13:12: remark: loop not vectorized: call instruction cannot be
vectorized [-Rpass-analysis]
res[x] = cbrt((double) x);
^
cbrt.cpp:11:10: remark: loop not vectorized (Force=true)
[-Rpass-missed=loop-vectorize]
#pragma omp simd
^
cbrt.cpp:11:10: warning: loop not vectorized: failed explicitly specified loop
vectorization [-Wpass-failed=loop-vectorize]
1 warning generated.
What is necessary to have cbrt() vectorizable? This works with recent Intel
compilers on Linux and GCC seems to also be capable to do this properly.</pre>
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