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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 --- - "More than one parameter has attribute returned!" after gvn/functionattrs interaction."
href="https://llvm.org/bugs/show_bug.cgi?id=30350">30350</a>
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<th>Summary</th>
<td>"More than one parameter has attribute returned!" after gvn/functionattrs interaction.
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>new bugs
</td>
</tr>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>mikael.holmen@ericsson.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=17243" name="attach_17243" title="Small reproducer">attachment 17243</a> <a href="attachment.cgi?id=17243&action=edit" title="Small reproducer">[details]</a></span>
Small reproducer
Can be reproduced with
opt -S -functionattrs -gvn -functionattrs red.ll
The input code looks like:
define i32 @f1(i32 %p1, i32 %p2) local_unnamed_addr {
%_tmp4 = icmp eq i32 %p1, %p2
br i1 %_tmp4, label %bb2, label %bb1
bb2: ; preds = %0
ret i32 %p2
bb1: ; preds = %0, %bb1
br label %bb1
}
The first functionattrs pass adds the "returned" attribute to %p2. Then gvn
comes and change the
ret i32 %p2
to
ret i32 %p1
but still leaves "returned" on %p2, and finally when functionattrs runs again
it now adds
"returned" to "%p1" (while it's still on %p2), leaving "returned" on both %p1
and %p2, and
then the verifier pukes on it.</pre>
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