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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Miscompilation after r355962: [SROA] Fix a crash when trying to convert a memset to an non-integral pointer"
href="https://bugs.llvm.org/show_bug.cgi?id=43526">43526</a>
</td>
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<tr>
<th>Summary</th>
<td>Miscompilation after r355962: [SROA] Fix a crash when trying to convert a memset to an non-integral pointer
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<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>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>dmajor@mozilla.com
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, listmail@philipreames.com, llvm-bugs@lists.llvm.org
</td>
</tr>
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<th>Blocks</th>
<td>43360
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=22613" name="attach_22613" title="Miscompilation analysis">attachment 22613</a> <a href="attachment.cgi?id=22613&action=edit" title="Miscompilation analysis">[details]</a></span>
Miscompilation analysis
After moving Firefox builds to clang 9.0.0, some of our tests failed because of
a miscompilation that began in r355962 according to a bisect.
Unfortunately I don't have a small repro and I'm not sure it's feasible to
produce one. The affected code is part of a huge binary that is built with LTO
and PGO, and we only see the issue on a single platform (Android ARM32) that is
difficult to build and debug locally.
I'm attaching a file containing a colleague's analysis of the generated code
near the point of failure (from
<a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1583907#c17">https://bugzilla.mozilla.org/show_bug.cgi?id=1583907#c17</a>). A value that we
needed was placed into r0, but then r0 was immediately overwritten by something
else.
@reames, is there any chance you might be able to have a look at the analysis
and intuit what went wrong? I'm not sure what other hope we have of debugging
this.</pre>
</div>
</p>
<div id="referenced">
<hr style="border: 1px dashed #969696">
<b>Referenced Bugs:</b>
<ul>
<li>
[<a class="bz_bug_link
bz_status_NEW "
title="NEW - [meta] 9.0.1 Release Blockers"
href="https://bugs.llvm.org/show_bug.cgi?id=43360">Bug 43360</a>] [meta] 9.0.1 Release Blockers
</li>
</ul>
</div>
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