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<base href="http://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Wrong code"
href="http://llvm.org/bugs/show_bug.cgi?id=21160">21160</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Wrong code
</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>LLVM Codegen
</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>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>LLVM + clang 3.6 for x86_64 miscompiles the following code with optimize option
"-O1".
We have tried hard to minimize the code, but this is the best result we have
obtained so far.
$ cat test.c
int a = 0;
int b = 0;
int c = 0;
int d = 0;
int e = 0;
int f = 0;
int g = 0;
int h = 0;
int i = 0;
int j = 0;
int k = 0;
int l = 0;
int m = 0;
int n = 0;
int o = 0;
int p = 0;
int main (void)
{
volatile int q = 0;
volatile int r = 0;
volatile int s = 0;
volatile int t = 0;
volatile int u = 0;
for (i = 0; i < 1; i++) {
volatile int v = 1;
a = m + 1;
b = n;
c = 1 / v;
d = r + o;
e = t;
f = p + t;
g = a + 1;
h = g + q;
j = s;
k = r + l;
}
int w = g | (int)(16777219.0L + u);
if (w != 16777219) {
__builtin_abort();
}
return 0;
}
$ clang test.c -O1
$ ./a.out
Aborted (core dumped)
$ clang -v
clang version 3.6.0
Target: x86_64-unknown-linux-gnu
Thread model: posix</pre>
</div>
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