[PATCH v2] forbid 8-byte atomic on Cortex M

[Tim Northover]

Hi Phoebe,

On 16 June 2014 19:24, Phoebe Buckheister <llvm at quasiparticle.net> wrote:
> Another try at disabling 8 byte atomics on Cortex M. Interestingly,
> llvm generated ldrex/strex instructions for plain 32 bit loads and
> stores on Cortex M, even though those are already atomic. Thus, emit
> exclusive accesses only for 64 bit accesses and only on !M, otherwise
> use whatever the core has: atomics up to 32 bit for M, up to 64 for the
> rest.

I think this looks like a reasonable change now. Do you have commit
access, or would you like me to apply it?

Cheers.

Tim.