<div dir="ltr">We may also be able to pick out an 'obvious winner' (perhaps looking for one that only requires standard conversions) before trying to build conversion sequences for all candidates.</div><div class="gmail_extra">
<br><br><div class="gmail_quote">On Thu, Oct 31, 2013 at 12:19 PM, Richard Smith <span dir="ltr"><<a href="mailto:richard@metafoo.co.uk" target="_blank">richard@metafoo.co.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">I suspect the problem is overload resolution for the several hundred overloads of each of 'operator<<', 'operator<<=', 'operator>>', and 'operator>>=' that are present here. Many of these have the same LHS parameter type; we could probably improve performance here by caching the computation of an implicit conversion sequence for a given (argument, parameter type) pair.</div>
<div class="HOEnZb"><div class="h5">
<div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Oct 31, 2013 at 10:05 AM, David Blaikie <span dir="ltr"><<a href="mailto:dblaikie@gmail.com" target="_blank">dblaikie@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><br><div class="gmail_quote"><div>On Wed, Oct 30, 2013 at 11:59 PM, Igor Vagulin <span dir="ltr"><<a href="mailto:igor.vagulin@gmail.com" target="_blank">igor.vagulin@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi All,<br>
<br>
We are evaluating switch to clang from gcc for our c++ application.<br>
Main focus is compilation speed, but we also look at address/memory<br>
sanitizer, c++11 support and c++ modules. I've tried to compile our<br>
project with clang++ but resulting compilation time is more than with<br>
gcc. Can someone give me a hint where might be a problem?<br>
<br>
Our project is bunch of ace-tao corba servants. Overall time with<br>
clang++ is about twice more than with gcc. To reproduce problem I<br>
preprocesssed one file and then compile it, result same - twice longer<br>
compilation. Don't know where to look further.<br></blockquote><div><br></div></div><div>If you're lucky, someone might look for you if you attach (or link to, if it's too big to attach) an example of the problem.<br>
<br>Otherwise, you might want to get started with a profiler and see where the hot parts of Clang/LLVM are in your example.<br><br>(also, consider trying with Clang top of tree (straight from svn/git) - the project moves fairly quickly)</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>
[root@ivagulin-pc ~]# time clang++ -c RemoveClusterObserverClang.cpp<br>
real 0m1.283s<br>
user 0m1.254s<br>
sys 0m0.024s<br>
[root@ivagulin-pc ~]# time g++ -c RemoveClusterObserverGcc.cpp<br>
real 0m0.576s<br>
user 0m0.524s<br>
sys 0m0.048s<br>
<br>
I use llvm-3.3 and cfe-3.3 compiled with folowing options. Sources of<br>
RemoveClusterObserver*cpp attached.<br>
+ cmake -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=Release<br>
'-DCMAKE_CXX_FLAGS_RELEASE=-O3 -g -mtune=amdfam10 -march=i686'<br>
'-DCMAKE_C_FLAGS_RELEASE=-O3 -g -mtune=amdfam10 -march=i686'<br>
-DCMAKE_EXE_LINKER_FLAGS_RELEASE=-Wl,--as-needed -Wl,--strip-all'<br>
'-DCMAKE_MODULE_LINKER_FLAGS_RELEASE=-Wl,--as-needed -Wl,--strip-all'<br>
'-DCMAKE_SHARED_LINKER_FLAGS_RELEASE=-Wl,--as-needed -Wl,--strip-all<br>
-shared' -DCMAKE_SKIP_RPATH=YES -DBUILD_SHARED_LIBS=YES<br>
-DLLVM_ENABLE_TIMESTAMPS=NO ..<br>
<span><font color="#888888"><br>
Igor Vagulin<br>
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