llvm dev - Oct 2017 - [LV] [ScalarEvolution] Feedback on bug 34965 - After r311849 Loop Vectorizer crashes with "The instruction should be scalarized"

Hi!

I uploaded a tentative patch for the following bug in LV
(https://bugs.llvm.org/show_bug.cgi?id=34965) but I have some concerns about it.
I would appreciate if someone with more experience in SE/PSE can provide some
feedback about current tentative fix and alternative solutions described in the
comments.

Thanks!
Diego Caballero,
Intel Vectorizer Team

Patches are best submitted to phabricator (or to the llvm-commits mailing list).
See also
https://llvm.org/docs/DeveloperPolicy.html#making-and-submitting-a-patch
<https://llvm.org/docs/DeveloperPolicy.html#making-and-submitting-a-patch>

- Matthias
> On Oct 25, 2017, at 5:21 PM, Caballero, Diego via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> Hi!
> 
> I uploaded a tentative patch for the following bug in LV
(https://bugs.llvm.org/show_bug.cgi?id=34965) but I have some concerns about it.
I would appreciate if someone with more experience in SE/PSE can provide some
feedback about current tentative fix and alternative solutions described in the
comments.
> 
> Thanks!
> Diego Caballero,
> Intel Vectorizer Team
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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On 10/25/2017 07:32 PM, Matthias Braun via llvm-dev
wrote:
> Patches are best submitted to phabricator (or to the llvm-commits 
> mailing list). See also 
> https://llvm.org/docs/DeveloperPolicy.html#making-and-submitting-a-patch
>
> - Matthias
+1

Even if you believe that the fix may not be correct, it is still best to 
post it for review. It is easiest for us to evaluate the situation that 
way. Include in the patch description all of the information relevant, 
for example, it is perfectly appropriate to include all of 
https://bugs.llvm.org/show_bug.cgi?id=34965#c6 in your patch description.

  -Hal

P.S. I agree with your conclusions based on your description of what's 
going on: We need to cache the results before we start transforming 
things. I also agree that we should potentially be concerned with 
maintaining the cache in the face of new predicates being added. Maybe 
we should instantiate the cached values as a separate setup after all 
predicates have been added?

>
>> On Oct 25, 2017, at 5:21 PM, Caballero, Diego via llvm-dev 
>> <llvm-dev at lists.llvm.org <mailto:llvm-dev at
lists.llvm.org>> wrote:
>>
>> Hi!
>>
>> I uploaded a tentative patch for the following bug in LV 
>> (https://bugs.llvm.org/show_bug.cgi?id=34965) but I have some 
>> concerns about it. I would appreciate if someone with more experience 
>> in SE/PSE can provide some feedback about current tentative fix and 
>> alternative solutions described in the comments.
>>
>> Thanks!
>> Diego Caballero,
>> Intel Vectorizer Team
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
-- 
Hal Finkel
Lead, Compiler Technology and Programming Languages
Leadership Computing Facility
Argonne National Laboratory

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