[patch] Shark reroute LLVM atomic intrinsics to Zero

[Andrew Haley]

Gary Benson wrote:

> Having said that, is there any reason to use atomic intrinsics on a
> single processor system?

Yes.  The problem is essentially the same on multi-core and single-core
systems.  A thread switch can happen at any time.

> And, do multiprocessor ARM systems exist?
> If the answers to those questions are both no then we could make Shark
> emit non-atomic code to emulate cmpxchg when it is running on a single
> processor system, which would sidestep the issue for ARM entirely.

I don't think that's possible without making a system call.

Andrew.