Why Clang

[Mark Felder]

On Tue, 19 Jun 2012 10:14:25 -0500, Fred Morcos <fred.morcos at gmail.com>  
wrote:

> I would also guess that the base system is stuck with gcc ~4.1 due to
> the GPLv3-ization of later gcc version. Is that correct?

Yes, 4.2.1 is the latest we can use.

Also, I have no idea what version of Clang Michael is using on OSX. That  
tag means nothing to me; for all I know that really could be back in Clang  
2.1 days which makes this exercise pointless. We need to be comparing at a  
minimum the very latest Clang to GCC 4.2.1. Further benchmarks against the  
latest GCC is welcome, but we should care more about not having a huge  
performance regression in comparison to what GCC 4.2.1 already provides us.