<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 - LTO seems to be optimizing away calls to compiler generated symbols"
href="https://bugs.llvm.org/show_bug.cgi?id=34169">34169</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>LTO seems to be optimizing away calls to compiler generated symbols
</td>
</tr>
<tr>
<th>Product</th>
<td>tools
</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>release blocker
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>lto
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>phosek@chromium.org
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>We're seeing this issue when building our kernel and low-level libraries (below
libc) with LTO. This appears to be a recent regression, we don't see these
issues with our Clang build from April.
<a href="https://storage.googleapis.com/fuchsia-build/lld/libuserboot.cpio">https://storage.googleapis.com/fuchsia-build/lld/libuserboot.cpio</a>
/usr/local/google/home/phosek/clang-llvm/llvm/out/lld/bin/ld.lld: error:
undefined symbol: memmove
<span class="quote">>>> referenced by ld-temp.o
>>> lto.tmp:(bootstrap)</span >
/usr/local/google/home/phosek/clang-llvm/llvm/out/lld/bin/ld.lld: error:
undefined symbol: memcpy
<span class="quote">>>> referenced by ld-temp.o
>>> lto.tmp:(bootstrap)</span >
<a href="https://storage.googleapis.com/fuchsia-build/lld/libmagenta.cpio">https://storage.googleapis.com/fuchsia-build/lld/libmagenta.cpio</a>
/usr/local/google/home/phosek/clang-llvm/llvm/out/lld/bin/ld.lld: error:
undefined symbol: __stack_chk_fail
>>> referenced by acpi.cpp:54
(kernel/platform/pc/acpi.cpp:54)
>>>
lto.tmp:(platform_init_acpi_tables)</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>