[PATCH 06/21] ARC: Atomics and Locking primitives

[Joseph Myers]

On Tue, 18 Dec 2018, Vineet Gupta wrote:

> +#define USE_ATOMIC_COMPILER_BUILTINS 0

There is a strong preference for new ports to use 1 for this rather than 0 
(and not to have any asms in their atomic-machine.h unless there's some 
reason use of built-in functions is unsuitable) - see the recently posted 
C-Sky version, for example.  If you can't use 1, there should be a good 
reason, documented in a comment, for using asms instead of compiler 
built-in functions (e.g. if the compiler built-in functions would result 
in libatomic dependencies, which are unsuitable for glibc, rather than 
being expanded inline).

-- 
Joseph S. Myers
joseph@codesourcery.com