[Buildroot] [autobuild.buildroot.net] Build results for 2018-04-25

[Romain Naour]

Le 30/04/2018 à 10:17, Romain Naour a écrit :
> Hi Thomas,
> 
> Le 30/04/2018 à 09:15, Thomas Petazzoni a écrit :
>> Hello,
>>
>> On Mon, 30 Apr 2018 00:15:18 +0200, Romain Naour wrote:
>>
>>>> Detail of failures
>>>> ------------------
>>>>
>>>> microblazeel |                          boost | TIM | http://autobuild.buildroot.net/results/b42d68c66d8ea035845a28c5530ef0682fd95713 |     
>>>> microblazeel |                   flare-engine | TIM | http://autobuild.buildroot.net/results/af976a4805fb8b3f0c17a8e3a1f901b2255caa0b |       
>>>
>>> I tried to reproduce this issue with the upcoming gcc 8.1 for microblaze but
>>> flare-engire build fine with it.
>>>
>>> git bisect helped to find a patch [1] fixing an infinite loop in RTL DSE
>>> optimizer. Also, back porting the patch to gcc 7.3.0 fix the issue.
>>>
>>> Since this patch is not specific to microblaze, but in gcc's code, I'm not sure
>>> what we need to do.
>>> Either back port the patch to affected gcc version and take the risk to break
>>> something with other architecture or optimization level.
>>> Or add BR2_TOOLCHAIN_HAS_GCC_BUG_85180 option and wait for gcc 8.
>>>
>>> Maybe it's easier to add an autobuilder exception for boost and flare-engine on
>>> microblaze?
>>>
>>> It's not clear if other architecture can be affected.
>>>
>>> Thoughts?
>>
>> First of all, thanks for this investigation!
> 
> You're welcome
> 
>> I believe we need to report this to upstream gcc (i.e that gcc 7.x is
>> affected) and see if they backport to the gcc 7.x branch. If they do,
>> then the solution is simple: also backport the patch on our side, until
>> they do a new 7.x release.
> 
> For now I don't have an account in the gcc bugzilla to reply to the bug report.
> I've asked for a new account, It should be activated in few days.

Richard Biener replied
"The bug isn't a regression so technically it doesn't qualify.  OTOH it
looks reasonably safe to backport and the bug is annoying."

I'm waiting for the backport in the gcc-7-branch.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85180

Best regards,
Romain

> 
> Best regards,
> Romain
> 
>>
>> Thomas
>>
>