<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 - InstCombine infinite loop"
href="https://bugs.llvm.org/show_bug.cgi?id=46271">46271</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>InstCombine infinite loop
</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>enhancement
</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>craig.topper@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>This sequence causes instcombine to run in an infinite loop. It never even its
the max iteration check because we're always adding nodes to the worklist.
define i8 @foo(<2 x i8> %updatedret.i.i.i213) {
%a = icmp sgt <2 x i8> %updatedret.i.i.i213, <i8 -1, i8 -1>
%b = select <2 x i1> %a, <2 x i8> %updatedret.i.i.i213, <2 x i8> <i8 undef,
i8 -1>
%resultvec.i = xor <2 x i8> %b, <i8 undef, i8 -1>
%storeval.i.1.i = extractelement <2 x i8> %resultvec.i, i32 1
ret i8 %storeval.i.1.i
}
Extract from <a href="https://github.com/ispc/ispc/issues/1788">https://github.com/ispc/ispc/issues/1788</a> hopefully this is the
same issue there, but I"m not sure because the full IR hit the max iteration
limit.</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>