[llvm] r294264 - [LVI] Switch from BFS to DFS exploration order

[Hans Wennborg via llvm-commits]

On Fri, Feb 24, 2017 at 9:30 AM, Mehdi Amini <mehdi.amini at apple.com> wrote:
>
>> On Feb 24, 2017, at 9:27 AM, Hans Wennborg <hans at chromium.org> wrote:
>>
>> On Fri, Feb 24, 2017 at 9:04 AM, Mehdi Amini <mehdi.amini at apple.com> wrote:
>>>
>>>> On Feb 21, 2017, at 11:30 AM, Hans Wennborg via llvm-commits <llvm-commits at lists.llvm.org> wrote:
>>>>
>>>> I'm not saying there's anything wrong with the change; it sounds great
>>>> to me. It's just that since it's a non-trivial change, and not fixing
>>>> a regression from 3.9, I don't want to risk merging it this far into
>>>> the release process (according to the schedule we should tag 'final'
>>>> today).
>>>>
>>>> We'll get to enjoy this improvement in llvm 5 instead.
>>>
>>> Why not 4.1?
>>
>> Because there's no plan for a 4.1
>> (http://blog.llvm.org/2016/12/llvms-new-versioning-scheme.html).
>>
>> If you mean 4.0.1, it's up to Tom if he wants to take it. (I
>> personally think of the stable releases mostly as bug-fix releases
>> though.)
>
> Well, one can see “exploding the memory consumption” as a bug :)

That's a good point :-)

>
> —
> Mehdi
>
>>
>>
>>>> On Tue, Feb 21, 2017 at 11:17 AM, Daniel Berlin <dberlin at dberlin.org> wrote:
>>>>> FWIW: I mentioned he was welcome to try, but i did not have time to try to
>>>>> verify the sanity of doing it.
>>>>> As for riskiness, at this point, it's been tested on billions of lines of
>>>>> code, (including entire os distro compiles).
>>>>>
>>>>> I'm not horribly worried about the percent chance it will cause regressions
>>>>> in *compile time* (In fact, it'll likely be a huge net positive in almost
>>>>> all cases), but i mostly agree with Hal that we should try to stick to stuff
>>>>> that maybe hasn't had to have followups, and isn't basically a week or two
>>>>> old.
>>>>>
>>>>>
>>>>>
>>>>> On Tue, Feb 21, 2017 at 10:52 AM, Hans Wennborg via llvm-commits
>>>>> <llvm-commits at lists.llvm.org> wrote:
>>>>>>
>>>>>> ,
>>>>>>
>>>>>> On Sat, Feb 18, 2017 at 3:29 PM, Joerg Sonnenberger <joerg at bec.de> wrote:
>>>>>>> On Mon, Feb 06, 2017 at 04:49:57PM -0800, Hans Wennborg wrote:
>>>>>>>> On Mon, Feb 6, 2017 at 4:42 PM, Joerg Sonnenberger via llvm-commits
>>>>>>>> <llvm-commits at lists.llvm.org> wrote:
>>>>>>>>> On Tue, Feb 07, 2017 at 12:25:24AM -0000, Philip Reames via
>>>>>>>>> llvm-commits wrote:
>>>>>>>>>> Author: reames
>>>>>>>>>> Date: Mon Feb  6 18:25:24 2017
>>>>>>>>>> New Revision: 294264
>>>>>>>>>>
>>>>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=294264&view=rev
>>>>>>>>>> Log:
>>>>>>>>>> [LVI] Switch from BFS to DFS exploration order
>>>>>>>>>
>>>>>>>>> Thanks! Hans, any comment on merging this into 4.0? It fixes one of
>>>>>>>>> the
>>>>>>>>> two remaining cases in pkgsrc where clang with normal optimiser
>>>>>>>>> settings
>>>>>>>>> hits 2GB VA.
>>>>>>>>
>>>>>>>> Well.. This just landed, and I don't think it's fixing a regression
>>>>>>>> from 3.9. While the change sounds great, I think we should just let it
>>>>>>>> go into the next release.
>>>>>>>
>>>>>>> It's been a while and I still would like to see this and the follow-up
>>>>>>> r294463 merged. That was discussed with Daniel Berlin already.
>>>>>>
>>>>>> I'm sorry, but I really do think this kind of change is too risky so
>>>>>> late in the release process.
>>>>>>
>>>>>> - Hans
>>>>>> _______________________________________________
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>>>>>> llvm-commits at lists.llvm.org
>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>>>
>>>>>
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>