[cfe-dev] About Clang - Features and Goals webpage

[Karen Shaeffer]

On Wed, Apr 23, 2014 at 11:19:37AM -0700, Richard Smith wrote:
> On Wed, Apr 23, 2014 at 2:21 AM, Konstantin Tokarev <annulen at yandex.ru>wrote:
> 
> >
> >
> > 23.04.2014, 07:04, "Sylvestre Ledru" <sylvestre at debian.org>:
> > > Hello,
> > >
> > > I would like to update this page:
> > > http://clang.llvm.org/features.html
> > >
> > > In particular, I would like to remove most of the information relative
> > > to performances. This for various reasons:
> > > * It is better if we leave third parties to do "independent" benchmark.
> > > * We compare Clang (version unspecified) with gcc 4.0 or 4.2.
> > > * The graphs have not been updated for a while.
> > > * Clang is well known now. I don't think we still need to explain why
> > > Clang is great.
> >
> > I disagree about the latter. Clang has a long-standing reputation of
> > compiler
> > which is faster than GCC, but generating slower code than GCC. On the
> > other hand,
> > recent releases of GCC greatly improved compilation speed, memory
> > consumption,
> > and diagnostics.
> >
> > So it would be useful to explain why Clang is still great when we have GCC
> > 4.9.
> 
> 
> Perhaps so, but the text being removed is not that explanation. It explains
> why Clang 2.9 was better than GCC 4.0, which is no longer relevant to
> anyone.

--- end quoted text ---

Hi,
I agree clang needs to document why it is a good choice compared to g++-4.9.
I believe g++-4.9.x will experience wide adoption in 2014 and 2015.

One issue likely is strongly in clang's favor: g++ tends to violate the standards
frequently as a matter of practicality. My understanding is it is deliberate
in the context of performance and implementation details. But there is a real
cost for folks who are not limiting their work to the g++ tool chain. I suspect
a lot of folks would want to be informed of these differences.

I speak of my experiences with g++-4.8.x and clang 3.3-xubuntu but have no idea how
these issues play out with current releases.

enjoy,
Karen
-- 
Karen Shaeffer                 Be aware: If you see an obstacle in your path,
Neuralscape Services           that obstacle is your path.        Zen proverb