<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 - -Wpass-failed not always working"
href="https://bugs.llvm.org/show_bug.cgi?id=35925">35925</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>-Wpass-failed not always working
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>All
</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>-New Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>trass3r@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Some unvectorizable code:
void foo(int r[8], int* ptr)
{
#pragma clang loop vectorize(enable)
// or: #pragma omp simd
for (int j = 0; j < 8; ++j)
if (r[j] < 1000)
r[j] = *ptr++;
}
$ clang -Werror=pass-failed -O3
compiles just fine because the loop unroller takes precedence.
Only when adding -fno-unroll-loops it produces the warning as expected:
<a href="https://godbolt.org/g/eiEB7G">https://godbolt.org/g/eiEB7G</a>.
This has been noted in 2015 already:
<a href="http://lists.llvm.org/pipermail/cfe-dev/2015-July/044264.html">http://lists.llvm.org/pipermail/cfe-dev/2015-July/044264.html</a>
"We should extend the diagnostics to all passes that could remove a loop"</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>