Re: Configure checks and optimizations/crc32 tests

Hi,

On 2015-08-14 15:35:45 +0300, Heikki Linnakangas wrote:
> >But we've played that whack-a-mole game in a bunch of configure tests
> >now, and it seems likely that more are coming with compilers getting
> >better. I'd not be surprised if some tests actually always succeed, we
> >just don't notice it because it's only on new compilers that have the
> >tested feature anyway...
> 
> Yeah, wouldn't be surprised if the other similar tests for all __sync_*
> family of functions had the same problem.

I don't think those are vulnerable because atomics do have a side effect
- they're memory barriers. Maybe if we'd specified relaxed (we don't)
consistency mode for the __atomic_* ones.

> >One way trying to fix this would be to explicitly disable optimizations
> >during tests. I'm not sure that's a good idea, but it's one.
> 
> I think adding the "return" is better.

Ok, will do.

Greetings,

Andres Freund