[Bug lto/59469] LLVM build failure with gcc LTO

[octoploid at yandex dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59469

--- Comment #5 from Markus Trippelsdorf <octoploid at yandex dot com> ---
(In reply to Andrew Pinski from comment #4)
> (In reply to Markus Trippelsdorf from comment #3)
> > BTW it is interesting that gcc compiles the attached testcase faster
> > when using LTO.
> > 
> >  % time g++ -flto=4 -Wfatal-errors -fPIC -shared -fno-rtti -O3 BasicBlock.ii
> > Function.ii
> > 52.48s user 0.59s system 168% cpu 31.545 total
> >  % time g++ -Wfatal-errors -fPIC -shared -fno-rtti -O3 BasicBlock.ii
> > Function.ii
> > 46.94s user 0.30s system 99% cpu 47.258 total
> > 
> > (for comparison clang trunk (70% faster):
> >   % time clang++ -Wfatal-errors -fPIC -shared -fno-rtti -O3 BasicBlock.ii
> > Function.ii
> > 15.48s user 0.14s system 99% cpu 15.628 total)
> 
> Is GCC configured with --enable-checking=release?  If not then you should
> not compare to LLVM's compile time.

Yes. Sorry, I forgot to mention it: --enable-checking=release PGO/LTO build.