<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Miscompile with collapse(4) on a triangular loop nest"
href="https://bugs.llvm.org/show_bug.cgi?id=47221">47221</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Miscompile with collapse(4) on a triangular loop nest
</td>
</tr>
<tr>
<th>Product</th>
<td>OpenMP
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</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>Clang Compiler Support
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>huberjn@ornl.gov
</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=23859" name="attach_23859" title="Makefile and test code used on x86-64 Linux with clang trunk to produce the error.">attachment 23859</a> <a href="attachment.cgi?id=23859&action=edit" title="Makefile and test code used on x86-64 Linux with clang trunk to produce the error.">[details]</a></span>
Makefile and test code used on x86-64 Linux with clang trunk to produce the
error.
The following triangular loop nest miscompiles on trunk when attempting to
collapse the whole loop nest. Device code is not generated causing `undefined
reference to` errors in the device linker.
<a href="https://godbolt.org/z/1xv6Eo">https://godbolt.org/z/1xv6Eo</a>
Using collapse(3) on the outer loop, the program compiles without errors but
miscompiles and returns incorrect values. Collapsing with < 3 works as expected
as does collapsing on the second loop instead.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>