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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [Dead Store Elimination + MemSSA] wrong code"
href="https://bugs.llvm.org/show_bug.cgi?id=46156">46156</a>
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<th>Summary</th>
<td>[Dead Store Elimination + MemSSA] wrong code
</td>
</tr>
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<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<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>
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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>Scalar Optimizations
</td>
</tr>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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</tr>
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<th>Reporter</th>
<td>paulsson@linux.vnet.ibm.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=23560" name="attach_23560" title="reduced testcase">attachment 23560</a> <a href="attachment.cgi?id=23560&action=edit" title="reduced testcase">[details]</a></span>
reduced testcase
The reduced program (also attached) should print '1', but with these options:
clang -O3 -march=z13 ./tc_wrong_dse_memssa.i -o a.out -w -mllvm
-enable-dse-memoryssa -mllvm -unroll-full-max-count=1;
, it prints '0'.
int a = 0, e = 0;
int b = 0;
short c[2] = {0, 0};
int *a_ptr = &a;
int main() {
c[0] = 1;
for (b = 1; b >= 0; b--)
e = *a_ptr = c[b];
c[0] = 0;
printf("checksum = %X\n", a);
}</pre>
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