[llvm] r285296 - [DAGCombiner] Add vector demanded elements support to computeKnownBits

[Davide Italiano via llvm-commits]

On Thu, Oct 27, 2016 at 3:48 PM, Davide Italiano <davide at freebsd.org> wrote:
> On Thu, Oct 27, 2016 at 3:36 PM, Juergen Ributzka via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
>> Hi Simon,
>>
>> I think this commit is causing timeouts on our LTO builds on green dragon:
>> http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto/10676/
>>
>> A build usually takes 45min and we kill them if they last more than 90min.
>>
>
> Out of curiosity, why is the timeout so high? I understand that false
> positives are not great, but 2x seems a little bit excessive.
> Have you already tried with 1.5x (or something around that value)?
>
> P.S. Ideally we {sh,c}ould have a decent infrastructure for tracking
> compile-time regressions (at least this is what I'm more concerned
> about because of LTO, others might care about runtime performance as
> well), but this is not a hill I want to die on (at least not today),
> and I still think lowering the timeout threshold could help finding
> regressions.
>

To clarify, I'm only talking about bots doing LTO, not the whole fleet.

-- 
Davide

"There are no solved problems; there are only problems that are more
or less solved" -- Henri Poincare