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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Segmentation fault: OpenMP critical hint(omp_sync_hint_uncontended):"
href="https://bugs.llvm.org/show_bug.cgi?id=49613">49613</a>
</td>
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<th>Summary</th>
<td>Segmentation fault: OpenMP critical hint(omp_sync_hint_uncontended):
</td>
</tr>
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<th>Product</th>
<td>OpenMP
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Runtime Library
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>kim.walisch@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<div>
<pre>Created <span class=""><a href="attachment.cgi?id=24654" name="attach_24654" title="Bash script that reproduces the segmentation fault">attachment 24654</a> <a href="attachment.cgi?id=24654&action=edit" title="Bash script that reproduces the segmentation fault">[details]</a></span>
Bash script that reproduces the segmentation fault
Hi,
While trying out the omp_sync_hint_uncontended synchronization hint with a
critical section I have hit a segmentation fault (Clang 11, Ubuntu 20.04 x64,
Intel i7-6700 CPU). With another synchronization hint such as
omp_sync_hint_contended or without any synchronization hint there is no
segmentation fault.
The attached crash-omp_sync_hint_uncontended.sh bash script clones my
primecount OpenMP project, changes the critical sections in the file
src/gourdon/AC.cpp to use the omp_sync_hint_uncontended synchronization hint,
builds the primecount program using clang++-11 (hardcoded in the bash script)
and then runs the program which immediately causes the segmentation fault:
$ ./crash-omp_sync_hint_uncontended.sh
./crash-omp_sync_hint_uncontended.sh: line 13: 71249 Segmentation fault
(core dumped) ./primecount 1e15 --AC
I have also run the primecount binary using valgrind which gives a stack trace
of where the segmentation fault happened. I have attached the valgrind output
(Segmentation-fault.txt) to this bug report.
Regards,
Kim Walisch</pre>
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