<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 vectorization of simple loop"
href="https://llvm.org/bugs/show_bug.cgi?id=27252">27252</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[ppc] missed vectorization of simple 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>Backend: PowerPC
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>carrot@google.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>Compile the following code with command line
~/llvm/obj3/bin/clang --target=powerpc64le-grtev4-linux-gnu -mvsx -mcpu=power8
-O2 -c t12.c -o t12.o
int foo(unsigned int* buf, unsigned int end, unsigned int endmask){
unsigned int* p;
int sum = 0;
for (p = buf; p < buf + end; ++p) {
sum += __builtin_popcount(*p);
}
return sum + __builtin_popcount(*p & endmask);
}
The simple loop is unrolled but not vectorized. If I change the last line to
return sum;
Then the loop can be vectorized.</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>