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<base href="https://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - DSE miscompile with TBAA"
href="https://llvm.org/bugs/show_bug.cgi?id=28189">28189</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>DSE miscompile with TBAA
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Windows NT
</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>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>eli.friedman@gmail.com
</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>Artificial evil testcase:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int f(int* x, int *y) {
*x = 10;
int z = *y;
*(float*)x = 1.0;
return z;
}
int (*ff)(int*,int*) = f;
int main() {
void* x = malloc(4);
printf("%d\n", ff(x, x));
}
Should print 10; with clang -O2, prints 0. Tested on x86-64 Linux with trunk
clang.
DSE is incorrectly ignoring the load when it eliminates the store.</pre>
</div>
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