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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - __builtin___clear_cache crashes the WebAssembly backend"
href="https://bugs.llvm.org/show_bug.cgi?id=42356">42356</a>
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<th>Summary</th>
<td>__builtin___clear_cache crashes the WebAssembly backend
</td>
</tr>
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<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>All
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>release blocker
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Backend: WebAssembly
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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</tr>
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<th>Reporter</th>
<td>gabravier@gmail.com
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=22129" name="attach_22129" title="7z archive containing the attachments">attachment 22129</a> <a href="attachment.cgi?id=22129&action=edit" title="7z archive containing the attachments">[details]</a></span>
7z archive containing the attachments
This code crashes the WebAssembly backend with a SIGSEGV :
void f(char *begin, char *end)
{
return __builtin___clear_cache((char *)begin, (char *)end);
}
Attached is a 7z file containing :
- The source file that crashed clang
- the associated .bc file that clang emits with -emit-llvm
- the different stack traces for the following three invocations of llc :
$ llc crash.bc
$ llc crash.bc -relocation-model=pic
$ llc crash.bc -relocation-model=static
- the error message I got when using the recommended invocation of bugpoint
from <a href="https://llvm.org/docs/HowToSubmitABug.html#code-generator-bugs">https://llvm.org/docs/HowToSubmitABug.html#code-generator-bugs</a>
I could not use bugpoint to pinpoint the crash more accurately, though I am
pretty sure that is directly related to __builtin___clear_cache. The stack
trace seems to implicate the assembly printer.</pre>
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