<div dir="rtl"><div dir="ltr"><span style="color:rgb(80,0,80);font-size:12.8000001907349px">LLVM_ENABLE_THREADS means that clang itself is thread-safe which may be important if you use it as a library but not as a command line compiler. It has nothing to do with clang output. With </span><span style="color:rgb(80,0,80);font-size:12.8000001907349px">LLVM_ENABLE_THREADS there is some mutex overhead which may be neglible.</span><br></div></div><div class="gmail_extra"><br><div class="gmail_quote"><div dir="ltr">2015-05-30 18:17 GMT+03:00 Edward Diener <span dir="ltr"><<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a>></span>:</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On 5/30/2015 1:35 AM, Yaron Keren wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Try to -DLLVM_ENABLE_THREADS:BOOL=OFF. Might not make a big difference.<br>
</blockquote>
<br></span>
Does this mean thread support in clang itself ? I need thread support in clang as I compile multi-threaded source.<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">
<br>
<br>
2015-05-30 5:08 GMT+03:00 Edward Diener<br>
<<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a><br></span>
<mailto:<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a>>>:<span class=""><br>
<br>
On 5/29/2015 9:35 PM, Justin Bogner wrote:<br>
<br>
On Friday, May 29, 2015, Edward Diener<br>
<<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a><br>
<mailto:<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a>><br></span>
<mailto:<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a><div><div class="h5"><br>
<mailto:<a href="mailto:eldlistmailingz@tropicsoft.com" target="_blank">eldlistmailingz@tropicsoft.com</a>>>><br>
wrote:<br>
<br>
I test Boost libraries mostly on Windows using various<br>
version of<br>
gcc 4.3 and up, VC++ 8.0 and up, and the latest version of<br>
clang<br>
which I build from source using mingw/gcc-4.8.1 in release<br>
mode.<br>
<br>
While clang is a great compiler when it comes to testing code,<br>
getting intelligent error message, and implementing the<br>
latest C++<br>
standard, it is noticably slower ( 2x or 3x at minimum )<br>
than the<br>
other compilers I use.<br>
<br>
The clang command line parameters usually being used are<br>
usually<br>
along the lines of:<br>
<br>
-c -x c++ -O0 -g -fno-inline -Wall -g -march=i686 -m32<br>
<br>
with the addition of 'std=c++11' occasionally depending on<br>
the test.<br>
<br>
Does anybody have any idea why clang is so much slower than<br>
any of<br>
the other compilers I use ? It does not seem to matter<br>
whether it is<br>
in C++03 mode or C++11 mode, it is noticeably slower than<br>
the other<br>
compilers.<br>
<br>
<br>
How are you building clang? I suspect that you're using a debug<br>
build of<br>
clang, which is quite slow.<br>
<br>
<br>
"which I build from source using mingw/gcc-4.8.1 in release mode."<br>
</div></div></blockquote><div class="HOEnZb"><div class="h5">
<br>
<br>
_______________________________________________<br>
cfe-dev mailing list<br>
<a href="mailto:cfe-dev@cs.uiuc.edu" target="_blank">cfe-dev@cs.uiuc.edu</a><br>
<a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev" target="_blank">http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev</a><br>
</div></div></blockquote></div><br></div>