[llvm] [LV] Support strided load with a stride of -1 (PR #128718)

[Florian Hahn via llvm-commits]

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@@ -1115,6 +1115,7 @@ class LoopVectorizationCostModel {
     CM_Widen_Reverse, // For consecutive accesses with stride -1.
     CM_Interleave,
     CM_GatherScatter,
+    CM_Strided,
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fhahn wrote:

Do we have test cases showing the scenarios we would not be able to handle?

One thing to consider w.r.t. to adding new logic in the legacy cost model path is that it will lead to more/duplicated work during the migration away from making decisions there

https://github.com/llvm/llvm-project/pull/128718