<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 - std::exp() produces infinite loop on Windows with -Ofast"
href="https://bugs.llvm.org/show_bug.cgi?id=32398">32398</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>std::exp() produces infinite loop on Windows with -Ofast
</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>
<tr>
<th>OS</th>
<td>Windows XP
</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>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>techmeology@techmeology.co.uk
</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=18159" name="attach_18159" title="Demonstration of the bug">attachment 18159</a> <a href="attachment.cgi?id=18159&action=edit" title="Demonstration of the bug">[details]</a></span>
Demonstration of the bug
When cross compiling for Windows (I haven't tested native compile on Windows),
std::exp() is miscompiled as an infinite loop if -Ofast is used. exp() works
correctly, and std::exp() works correctly on Linux.
Clang version: 297935 (Also tried a 4.0.0 pre-release with similar results)
OS: Arch Linux
Steps to reproduce: see build.sh in the tarball
Expected result: No infinite loop should be produced.
Actual result: The produced IR has a branch to a branch to itself (i.e: an
infinite loop).
Contents of the tarball:
build.sh
Shows how I produced all the files in the out directory.
exp.cpp
A minimal reproducer that demonstrates the bug.
out/windows_ofast/exp_expanded.cpp
The preprocessed version of exp.cpp on my system for -Ofast on Windows
out/windows_ofast/exp.bc
The generated IR bitcode for exp.cpp
The remaining files are analogous for -O3 and for native build.</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>