[PATCH] D101191: [InstCombine] Fully disable select to and/or i1 folding

Thu Jun 3 12:37:01 PDT 2021

rupprecht added a comment.

In D101191#2788596 <https://reviews.llvm.org/D101191#2788596>, @spatel wrote:

> In D101191#2783570 <https://reviews.llvm.org/D101191#2783570>, @rupprecht wrote:
>
>> In D101191#2782963 <https://reviews.llvm.org/D101191#2782963>, @rupprecht wrote:
>>
>>> The issue I'm seeing seems more directly caused by SLP vectorization, as it goes away with `-fno-slp-vectorize`. This patch merely unblocks that bad optimization AFAICT.
>>
>> Filed as http://llvm.org/PR50500
>
> We needed SLP to get to the problem state in that example, but the bug was in instcombine/instsimplify. 
> Should be fixed with:
> 7bb8bfa0622b <https://reviews.llvm.org/rG7bb8bfa0622b8ee55c3f748004dcf4d83d48cf97>

Thanks Sanjay! This fixes the unreduced miscompile we're seeing.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D101191/new/

https://reviews.llvm.org/D101191