[llvm] [LV][EVL]Support reversed loads/stores. (PR #88025)

[via llvm-commits]

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@@ -9383,12 +9377,17 @@ void VPWidenLoadRecipe::execute(VPTransformState &State) {
   }
 }
 
+static Value *reverseMask(IRBuilderBase &Builder, Value *Mask, Value *EVL,
+                          Value *AllTrueMask) {
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ayalz wrote:

It's obviously safe for reverse to utilize an all-true mask - as does the non-EVL vectorizer. Question was if it is ever beneficial not to do so? I.e., if in practice the mask of reverse is an unused operand that only wastes a register.

https://github.com/llvm/llvm-project/pull/88025