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<base href="https://llvm.org/bugs/" />
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Wrong constant folding"
href="https://llvm.org/bugs/show_bug.cgi?id=28504">28504</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Wrong constant folding
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>-New Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>ishiura-compiler@ml.kwansei.ac.jp
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>LLVM + clang 3.9 for x86_64 miscompiles the following code.
% cat test.c
int main (void)
{
signed char c = 1;
int i = (short) (signed char) ( c - (unsigned char) c + (c==1) ) ;
short s = c;
if (i != 1) __builtin_abort();
return 0;
}
% clang-3.9 test.c
% ./a.out
zsh: abort (core dumped) ./a.out
% clang-3.9 -v
clang version 3.9.0 (trunk 274023)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /xxxxx/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.0.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.1
Candidate multilib: .;@m64
Selected multilib: .;@m64</pre>
</div>
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