Re: HEADS UP: Updated llvm/clang to 3.4 in r261991

On Sun, 2014-02-16 at 21:06 +0100, Dimitry Andric wrote:
> Hi,
> 
> I have just upgraded our copy of llvm/clang to 3.4 release, in r261991.
> This version supports all of the features in the current working draft
> of the upcoming C++ standard, provisionally named C++1y.
> 
> The code generator's performance is greatly increased, and the loop
> auto-vectorizer is now enabled at -Os and -O2 in addition to -O3.  The
> PowerPC backend has made several major improvements to code generation
> quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
> backends have all seen major feature work.
> 
> Release notes for llvm and clang can be found here:
> <http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
> <http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>
> 
> Note that building lldb (using WITH_LLDB) will not work at this point,
> since our lldb snapshot was locally modified to be able to work with the
> old llvm 3.3 API.  Ed Maste will most likely fix this very soon (and
> maybe import a new snapshot, I hope :-).
> 
> Another important aspect for end-users and ports maintainers is the new
> compiler flag handling in clang 3.4.  It has become more strict, in the
> sense that it will now error out on flags it does not recognize, in
> particular most gcc-specific optimization fine-tuning flags.
> 
> Some ports which blindly use such gcc-specific flags will therefore be
> broken, but these are usually very easy to fix.  During the exp-run
> which was done with this new version of clang, several ports with the
> highest number of dependent ports (open-motif, libtheora, boost-libs,
> etc) have already been handled, but more work still needs to be done.
> 
> Last but not least, I hope we can now start using clang for more of our
> existing architectures, like powerpc, mips, and possibly even new ones
> like arm64.  Enjoy!
> 

Is OpenMP supported in this version? Clang 3.4 from ports barfs:

btw> /usr/local/bin/clang34 -fopenmp /tmp/foo.c 
clang: warning: argument unused during compilation: '-fopenmp'

Ditto the installed version of 3.3 under 10:

btw> clang -fopenmp /tmp/foo.c 
clang: warning: argument unused during compilation: '-fopenmp'






> -Dimitry
>