<html>
<head>
<base href="http://llvm.org/bugs/" />
</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 --- - SCEV extreme compile time and memory usage with sequence of muls in loop"
href="http://llvm.org/bugs/show_bug.cgi?id=18607">18607</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>SCEV extreme compile time and memory usage with sequence of muls in 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>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>Global Analyses
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>Matthew.Arsenault@amd.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=11935" name="attach_11935" title="Reduced testcase">attachment 11935</a> <a href="attachment.cgi?id=11935&action=edit" title="Reduced testcase">[details]</a></span>
Reduced testcase
opt -indvars on this testcase, which consists of a large sequence of muls
inside a loop seems to never complete and gets stuck spinning in SCEV. The time
seems to be from GroupByComplexity being repeatedly called with a vector with a
constantly increasing by Fibonacci number of items.
The number of muls can be cut down, and then it runs fast enough to see that it
does actually complete, but then it still takes several seconds.</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>