Transition to C11 atomics and memory model

[Joseph S. Myers]

On Tue, 16 Sep 2014, Torvald Riegel wrote:

> * mips use of __sync_lock_test_and_set for both _acq and _rel is
> surprising.  Is this __sync builtin different on mips, or is the _rel
> variant broken and needs a stronger barrier?

It sounds like a bug - specific to the case of (MIPS16, GCC before 4.7), 
as that's the only case where __sync_* get used on MIPS, and that case may 
not be widely used.  Please file in Bugzilla.  (__sync_* for MIPS16 then 
in turn ends up using out-of-line libgcc functions that call __sync_* 
built as non-MIPS16 code, but I see nothing special there to give a 
stronger barrier.)

-- 
Joseph S. Myers
joseph@codesourcery.com