<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 --- - Compile gets 10x slower (from 40s to 7m40s) due to using -g (on compiles with -fno-execptions)"
href="https://llvm.org/bugs/show_bug.cgi?id=28820">28820</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Compile gets 10x slower (from 40s to 7m40s) due to using -g (on compiles with -fno-execptions)
</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>DebugInfo
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>nicolasweber@gmx.de
</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>Get the attachment in <a href="show_bug.cgi?id=28820#c20">comment 20</a> at
<a href="https://bugs.chromium.org/p/chromium/issues/detail?id=630502#c20">https://bugs.chromium.org/p/chromium/issues/detail?id=630502#c20</a> (it's too
large for llvm bugzilla). Then run:
$ time bin/clang++ -arch x86_64 -O2 -isysroot $(xcrun -show-sdk-path)
-std=c++11 -c foo.ii
real 0m38.955s
user 0m37.844s
sys 0m1.105s
$ time bin/clang++ -arch x86_64 -O2 -isysroot $(xcrun -show-sdk-path)
-std=c++11 -c foo.ii -g
real 1m0.349s
user 0m58.321s
sys 0m2.016s
This seems like fairly reasonable overhead from debug info. But:
$ time bin/clang++ -arch x86_64 -O2 -isysroot $(xcrun -show-sdk-path)
-std=c++11 -c foo.ii -g -fno-exceptions
real 7m40.507s
user 7m38.627s
sys 0m1.880s
Enabling just -fno-execptions without -g is free:
$ time bin/clang++ -arch x86_64 -O2 -isysroot $(xcrun -show-sdk-path)
-std=c++11 -c foo.ii -fno-exceptions
real 0m41.568s
user 0m41.210s
sys 0m0.354s</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>