[llvm] r277690 - Revert "GVN-hoist: enable by default" & "Make GVN Hoisting obey optnone/bisect."

[Sebastian Pop via llvm-commits]

Thanks Bruno for the testcase.
I was able to reproduce the fail with clang and the preprocessed file.
I will investigate the reason of the ICE, and send a patch to fix this problem.

Thanks,
Sebastian

On Thu, Aug 4, 2016 at 12:25 PM, Daniel Berlin <dberlin at dberlin.org> wrote:
> I can't get gvn-hoist to fail on this testcase no matter what i do, even on
> darwin, with my own built clang at the same rev.
>
>
> On Thu, Aug 4, 2016 at 10:10 AM, Bruno Cardoso Lopes
> <bruno.cardoso at gmail.com> wrote:
>>
>> Hi Sebastian,
>>
>> Attached the reproducer with a preprocessed and bitcode testcase. Let
>> me know if you need any help.
>>
>> On Thu, Aug 4, 2016 at 7:30 AM, Sebastian Pop <sebpop at gmail.com> wrote:
>> > I will need a preprocessed file or a reduced testcase:
>> > with the same cmake options as the bot, I was not able to see the fail
>> > on x86_64-linux.
>> > This was both when compiling with the system's gcc 5.4 and clang 3.8.
>> > The fail may be related to the libc of the bot.
>> >
>> > Thanks,
>> > Sebastian
>> >
>> > On Thu, Aug 4, 2016 at 8:10 AM, Sebastian Pop <sebpop at gmail.com> wrote:
>> >> I am looking at this fail.
>> >> I think I have enough information from the bot on how to reproduce the
>> >> bug.
>> >>
>> >> On Thu, Aug 4, 2016 at 12:44 AM, Daniel Berlin <dberlin at dberlin.org>
>> >> wrote:
>> >>>
>> >>>
>> >>> On Wed, Aug 3, 2016 at 10:17 PM, Bruno Cardoso Lopes
>> >>> <bruno.cardoso at gmail.com> wrote:
>> >>>>
>> >>>> Hi Daniel,
>> >>>>
>> >>>> On Wed, Aug 3, 2016 at 9:59 PM, Daniel Berlin <dberlin at dberlin.org>
>> >>>> wrote:
>> >>>> > so here's the super-curious question in my mind:
>> >>>> >
>> >>>> > Why didn't this break when this was enabled by default for like a
>> >>>> > month
>> >>>> > before :)
>> >>>>
>> >>>> Not really sure why, I was not following the bots back then.
>> >>>
>> >>>
>> >>> Yeah, it's semi-rhetorical. It's just really odd, and makes me think
>> >>> it's
>> >>> related to one or more of the optimizations sebastian added (for
>> >>> example,
>> >>> not recomputing DFS numbers).
>> >>>
>> >>>>
>> >>>> Where
>> >>>> there many changes following up the time it got off? Another
>> >>>> possibility is that the bot could have been broken by another change
>> >>>> that hid this?
>> >>>> I can get my hands on the reproducer and send to you tomorrow if
>> >>>> that's
>> >>>> helpful.
>> >>>>
>> >>>
>> >>> That would be really helpful.
>> >>>
>> >>>>
>> >>>> -Bruno
>> >>>>
>> >>>> --
>> >>>> Bruno Cardoso Lopes
>> >>>> http://www.brunocardoso.cc
>> >>>
>> >>>
>>
>>
>>
>> --
>> Bruno Cardoso Lopes
>> http://www.brunocardoso.cc
>
>