[PATCH] D144128: [SLP] Check with target before vectorizing GEP Indices

Thu Mar 16 07:56:31 PDT 2023

fhahn added a comment.

In D144128#4199448 <https://reviews.llvm.org/D144128#4199448>, @zjaffal wrote:

> Hi this patch is causing some regressions. 
> If you look at the example I attached the code sequence is no longer being vectorised when it is beneficial to do so.
> https://godbolt.org/z/MTex1z73K
>
> Can you take a look please?

To add to what @zjaffal said, I am curious why the current cost-modeling wouldn't be sufficient to prevent cases where vectorizing GEPs would be not profitable?

The case @zjaffal shared requires a more costly vector GEP, but the cost is offset by the benefits from vectorizing the rest of the tree.

Repository:
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  https://reviews.llvm.org/D144128/new/

https://reviews.llvm.org/D144128