[PATCH] D79145: Allow gep (select) combine with non-constant operands

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In D79145#2014188 <https://reviews.llvm.org/D79145#2014188>, @rampitec wrote:

> In fact I have created two more changes: D79217 <https://reviews.llvm.org/D79217> and D79218 <https://reviews.llvm.org/D79218> to process select and phi with gep operands right in SROA. It is more code but looks cleaner:
>
> 1. It will only touch patterns already considered by SROA.
> 2. It will give InstCombiner a chance to convert it back if SROA did not succeed.
> 3. There is zero chance it will loop forever.
> 4. It does not call expensive GetUnerlyingObject.
>
>   If those two look better I would prefer modifications in SROA and drop this.


If we can deal with this in SROA directly, that would be better. We generally do not want to increase instruction count in InstCombine (as the 2nd test is showing here).


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  https://reviews.llvm.org/D79145/new/

https://reviews.llvm.org/D79145