[PATCH] D88569: [DAGCombiner] Call SimplifyDemandedBits to simplify EXTRACT_VECTOR_ELT

Tue Jun 21 08:09:00 PDT 2022

RKSimon added a comment.

In D88569#3597648 <https://reviews.llvm.org/D88569#3597648>, @deadalnix wrote:

> In D88569#3597508 <https://reviews.llvm.org/D88569#3597508>, @deadalnix wrote:
>
>> Testing that now, I'll let you know.
>
> So it definitively affects the codegen, but it's not clear if this is better or worse.

Yeah that seems about right

@foad its up to you if you want to persevere, we already have SimplifyDemandedBits support for cases where all uses of the vector are extracts - it looks like we now known why it was never extended beyond that...

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https://reviews.llvm.org/D88569