[Mesa-dev] [PATCH 1/2] configure: check if -latomic is needed for __atomic_*

[Emil Velikov]

On 19 September 2017 at 13:01, Grazvydas Ignotas <notasas at gmail.com> wrote:
> On Tue, Sep 19, 2017 at 2:04 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>> On 19 September 2017 at 10:12, Grazvydas Ignotas <notasas at gmail.com> wrote:
>>> On Mon, Sep 18, 2017 at 11:30 PM, Matt Turner <mattst88 at gmail.com> wrote:
>>>> On Mon, Sep 18, 2017 at 12:28 PM, Grazvydas Ignotas <notasas at gmail.com> wrote:
>>>>> On some platforms, gcc generates library calls when __atomic_* functions
>>>>> are used, but does not link the required library automatically. Detect
>>>>> this and add the library when needed.
>>>>>
>>>>> This change was tested on armel (library was added) and on x86_64 (was
>>>>> not, as expected).
>>>>>
>> On one hand I see the reason why things are as-is. On the other its
>> rather odd that I couldn't find an official GCC doc that describes the
>> lot.
>> Most likely I failed at searching.
>
> I can't find it either. there is only this wiki that looks more like a
> design document:
> https://gcc.gnu.org/wiki/Atomic/GCCMM
>
> If I understand it right, when gcc can't do the operations with
> instructions it emits calls, but doesn't care how they are satisfied
> and leaves dealing with that to the application. libatomic is provided
> since 4.8, but there is no requirement to use it (to allow using
> something else?).
>
Right, I saw the article but got carried away looking at the provided
implementation ;-)

With the link added to the commit message the series is
Reviewed-by: Emil Velikov <emil.velikov at collabora.com>

Barring any objections, I'll push the lot in a couple of days.

-Emil