GCC 4.7.0 and C++ atomics

[Richard Henderson]

On 03/08/12 00:17, Sebastian Huber wrote:
> thanks for the hints.  Thus if we want to use the C++ atomic operations on 32-bit ARM in RTEMS we have to implement everything in
> 
> libgcc/config/arm/linux-atomic.c
> 
> and place it in e.g.
> 
> libgcc/config/arm/rtems-atomic.c

Possibly.  It really depends on how rtems attacks the problem of
atomic operations across ARM cpu revisions.  I have no opinion
as to what solution should be used.

> I guess similar procedures are required for other architectures. 

Not really.  ARM is unique in having an atomic insn (SWP) that
stops working in later ISA revisions, and a required memory
barrier (DMB) introduced late in the ISA revision history that
isn't a backward-compatible NOP.


r~