<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?] Failure to simplify branch-less logic code"
href="https://bugs.llvm.org/show_bug.cgi?id=43199">43199</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[InstCombine?] Failure to simplify branch-less logic code
</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>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>lebedev.ri@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre><a href="https://godbolt.org/z/MVN3j">https://godbolt.org/z/MVN3j</a>-
<a href="https://rise4fun.com/Alive/UCaS">https://rise4fun.com/Alive/UCaS</a>
bool is_not_ub_naive(char *Base, unsigned long Offset, char *&Offseted) {
Offseted = reinterpret_cast<char*>(intptr_t(Base) + Offset);
return ((Base != nullptr || Offset == 0) &&
(Offseted != nullptr || Offset == 0));
}
bool is_not_ub_best(char *Base, unsigned long Offset, char *&Offseted) {
Offseted = reinterpret_cast<char*>(intptr_t(Base) + Offset);
return ((Base != nullptr) == (Offseted != nullptr));
}
`is_not_ub_naive()` doesn't get flattened but that isn't the point here.
Even if i flatten it manually down to `@is_not_ub_flat_naive`, it still
doesn't get optimized down to `@is_not_ub_best`...</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>