<html>
<head>
<base href="https://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 --- - [ppc] missed chance to use rlwnm"
href="https://llvm.org/bugs/show_bug.cgi?id=27356">27356</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[ppc] missed chance to use rlwnm
</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>All
</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>Backend: PowerPC
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>spatel+llvm@rotateright.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>This example came up in <a href="http://reviews.llvm.org/D19087">http://reviews.llvm.org/D19087</a> :
define i1 @and_cmp_variable_power_of_two(i32 %x, i32 %y) {
%shl = shl i32 1, %y
%and = and i32 %x, %shl
%cmp = icmp eq i32 %and, %shl
ret i1 %cmp
}
$ llc -o - andn.ll -mtriple=powerpc64-apple-darwin
_ li r2, 1
slw r2, r2, r4
and r2, r3, r2
cntlzw r2, r2
nor r2, r2, r2
rlwinm r3, r2, 27, 31, 31
blr
Double-check to make sure because my PPC is beyond rusty, but I think this is:
subfic r4, r4, 32
rlwnm r3, r3, r4, 31, 31</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>