Re: lib/53051: __atomic_is_lock_free missing on NetBSD/sparc

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Sun, Dec 23, 2018 at 10:25:00AM +0000, Martin Husemann wrote:
> The following reply was made to PR lib/53051; it has been noted by GNATS.
> 
>  On Sat, Dec 22, 2018 at 11:05:27AM -0800, Jason Thorpe wrote:
>  > So, the way I understand this is that, on the "sparc" architecture,
>  > this would return true on a uniprocessor system and false on a
>  > multiprocessor system.
>  
>  My understanding is that it would have to always return false - there
>  are effectively no lock free atomics on sparcv8 or earlier.

The complication is that the ABI kind of assumes that you can mix code
compiled with different target CPU flags and they can interoperate. I.e.
code targetting v8a and code targetting the generic v8 should be able to
interoperate. That's painful in the current code structure.

Joerg