On Mon, 17 Feb 2014, Torvald Riegel wrote:

On Mon, 2014-02-17 at 18:59 +0000, Joseph S. Myers wrote:

quoted

On Sat, 15 Feb 2014, Torvald Riegel wrote:

quoted

glibc is a counterexample that comes to mind, although it's a smaller
code base.  (It's currently not using C11 atomics, but transitioning
there makes sense, and some thing I want to get to eventually.)

glibc is using C11 atomics (GCC builtins rather than _Atomic / 
<stdatomic.h>, but using __atomic_* with explicitly specified memory model 
rather than the older __sync_*) on AArch64, plus in certain cases on ARM 
and MIPS.

I think the major steps remaining is moving the other architectures
over, and rechecking concurrent code (e.g., for the code that I have

I don't think we'll be ready to require GCC >= 4.7 to build glibc for 
another year or two, although probably we could move the requirement up 
from 4.4 to 4.6.  (And some platforms only had the C11 atomics optimized 
later than 4.7.)

-- 
Joseph S. Myers
joseph@codesourcery.com