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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Seg fault due to miscompile from new stack coloring data flow analysis"
href="https://llvm.org/bugs/show_bug.cgi?id=27903">27903</a>
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<th>Summary</th>
<td>Seg fault due to miscompile from new stack coloring data flow analysis
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Common Code Generator Code
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>tejohnson@google.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, thanm@google.com
</td>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>During a clang bootstrap with ThinLTO on linux using the gold linker,
llvm-tblgen started seg faulting. I bisected this to r270559 - Rework/enhance
stack coloring data flow analysis. It also goes away when compiling with
-no-stack-coloring.
I was able to narrow this down to utils/TableGen/RegisterInfoEmitter.cpp, and
further to when _ZN4llvm11raw_ostreamlsEl is imported into
RegisterInfoEmitter.cpp from lib/Support/raw_ostream.cpp. This is eventually
inlined into
_ZN12_GLOBAL__N_119RegisterInfoEmitter9runMCDescERN4llvm11raw_ostreamERNS1_13CodeGenTargetERNS1_14CodeGenRegBankE.
To reproduce, untar the attached tblget.tgz. Change the paths in all.sh,
link.sh and run.sh to point to your own build and source trees. Then run all.sh
and it will run through 3 llc/link/run cycles. The first should fail and the
latter 2 should work. The all.sh script describes what is different about the
three. I have the llvm IR for the good and bad files in the same location as
the good and bad files but with the .ll extension.
I tried using bugpoint to narrow further, but couldn't get the compile steps to
link correctly with the rest of the native .o files.</pre>
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