[PATCH] [ARC] Add support for atomic memory built-in.

[Joern Wolfgang Rennecke]

On 07/12/15 13:25, Claudiu Zissulescu wrote:
>
> Tested with dg.exp (when passing -matomic to gcc compiler line, the atomic tests are also successfully executed).
The comment before "*memory_barrier" could use some elaboration on what 
it does for TARGET_HS.
Otherwise, this is OK.