<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><span class="vcard"><a class="email" href="mailto:richard-llvm@metafoo.co.uk" title="Richard Smith <richard-llvm@metafoo.co.uk>"> <span class="fn">Richard Smith</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - a pass error, this pass never consider data overflow"
href="https://bugs.llvm.org/show_bug.cgi?id=40496">bug 40496</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>INVALID
</td>
</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - a pass error, this pass never consider data overflow"
href="https://bugs.llvm.org/show_bug.cgi?id=40496#c1">Comment # 1</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - a pass error, this pass never consider data overflow"
href="https://bugs.llvm.org/show_bug.cgi?id=40496">bug 40496</a>
from <span class="vcard"><a class="email" href="mailto:richard-llvm@metafoo.co.uk" title="Richard Smith <richard-llvm@metafoo.co.uk>"> <span class="fn">Richard Smith</span></a>
</span></b>
<pre>This example has undefined behaviour due to signed overflow. In a correct
program, it is not possible for adding an unsigned char to a positive integer
to produce a negative integer, so the optimisation is correct.
If you want to write nonstandard code that assumes that signed overflow wraps
around, you can use -fwrapv to define this otherwise-undefined behaviour as
wrapping.</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>