[PATCH] D115955: [SLP]Alternate vectorization for cmp instructions.

[Alexey Bataev via Phabricator via llvm-commits]

ABataev added a comment.

In D115955#3322857 <https://reviews.llvm.org/D115955#3322857>, @uabelho wrote:

> In D115955#3322721 <https://reviews.llvm.org/D115955#3322721>, @ABataev wrote:
>
>> In D115955#3322699 <https://reviews.llvm.org/D115955#3322699>, @uabelho wrote:
>>
>>> In D115955#3322693 <https://reviews.llvm.org/D115955#3322693>, @ABataev wrote:
>>>
>>>> In D115955#3322678 <https://reviews.llvm.org/D115955#3322678>, @uabelho wrote:
>>>>
>>>>> I think I'm seeing a miscompile with this patch on trunk. Are we aware of any such problems?
>>>>
>>>> Do you have a reproducer or something like this?
>>>
>>> Not yet. I'm trying to extract something but thought I'd ask if you're already aware of any miscompilation problems in the meantime.
>>
>> No.
>
> Ok, here's a reproducer:
>
>   opt --passes=slp-vectorizer slp.ll -o - -S
>
> With this patch, the function returns the value 2. Without the patch the value returned is 0.
> This can be seen with
>
>   build-all/bin/opt --passes=slp-vectorizer slp.ll -o - -S | build-all/bin/opt -O3 -o - -S
>
> with/without this patch.
> F22116201: slp.ll <https://reviews.llvm.org/F22116201>

Fix https://reviews.llvm.org/D119855


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https://reviews.llvm.org/D115955