[llvm] [LV] Convert gather loads with invariant stride into strided loads (PR #147297)

[Mel Chen via llvm-commits]

Mel-Chen wrote:

> > I presume we will need to handle VPWidenStridedLoadRecipes in planContainsAdditionalSimplifcations and skip the assertion?
> 
> I’ve previously forced the cost model to always return profitable in order to trigger the transformation, and didn’t encounter any assertions. I plan to use the same method to test against the llvm-test-suite and see if any issues come up.

@lukel97 I think you're right—planContainsAdditionalSimplifications will need to be changed. It's just that right now, the costs for gather and strided load are exactly the same, so it works fine no matter how I execute it. Once the costs are corrected, this issue will become apparent.


https://github.com/llvm/llvm-project/pull/147297