r336467 - [OPENMP] Fix PR38026: Link -latomic when -fopenmp is used.

[Jonas Hahnfeld via cfe-commits]

[ + cfe-commits ]

Reverted in r337722, I've reopened the bug.

Regards,
Jonas

On 2018-07-23 11:37, Alexey Bataev wrote:
> Hi Jonas, yes, go ahead.
> 
> Best regards,
> Alexey Bataev
> 
>> 23 июля 2018 г., в 5:16, Jonas Hahnfeld <hahnjo at hahnjo.de>
> написал(а):
>> 
>>> On 2018-07-23 11:08, Jonas Hahnfeld via cfe-commits wrote:
>>>> On 2018-07-19 20:55, Hal Finkel wrote:
>>>>> On 07/19/2018 09:01 AM, Jonas Hahnfeld wrote:
>>>>>> On 2018-07-19 15:43, Hal Finkel wrote:
>>>>>>> On 07/16/2018 01:19 PM, Jonas Hahnfeld wrote:
>>>>>>> [ Moving discussion from https://reviews.llvm.org/D49386 to the
>>>>>>> relevant comment on cfe-commits, CC'ing Hal who commented on
> the
>>>>>>> original issue ]
>>>>>>> 
>>>>>>> Is this change really a good idea? It always requires libatomic
> for
>>>>>>> all OpenMP applications, even if there is no 'omp atomic'
> directive
>>>>>>> or
>>>>>>> all of them can be lowered to atomic instructions that don't
>>>>>>> require a
>>>>>>> runtime library. I'd argue that it's a larger restriction than
> the
>>>>>>> problem it solves.
>>>>>> 
>>>>>> Can you please elaborate on why you feel that this is
> problematic?
>>>>> 
>>>>> The linked patch deals with the case that there is no libatomic,
>>>>> effectively disabling all tests of the OpenMP runtime (even
> though
>>>>> only few of them require atomic instructions). So apparently
> there
>>>>> are
>>>>> Linux systems without libatomic. Taking them any chance to use
> OpenMP
>>>>> with Clang is a large regression IMO and not user-friendly
> either.
>>>> 
>>>> If there's a significant population of such systems, then this
>>>> certainly
>>>> seems like a problem.
>>>> 
>>>> Let's revert this for now while we figure out what to do (which
> might
>>>> just mean updating the documentation to include OpenMP where we
> talk
>>>> about atomics).
>>> 
>>> Alexey, what do you think? Can I go ahead and revert this commit?
>>> 
>>> Thanks,
>>> Jonas
>> 
>> Meh, my message got blocked by @hotmail.com :-( I hope you received
> the
>> message(s) via the mailing list...
>> 
>> Regards,
>> Jonas
>>