[llvm] [LV][EVL] Support reduction idioms using tail folding with EVL. (PR #90184)

[Florian Hahn via llvm-commits]

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@@ -2139,6 +2146,62 @@ class VPReductionRecipe : public VPSingleDefRecipe {
   }
 };
 
+/// A recipe to represent inloop reduction operations with vector-predication
+/// intrinsics, performing a reduction on a vector operand with the explicit
+/// vector length (EVL) into a scalar value, and adding the result to a chain.
+/// The Operands are {ChainOp, VecOp, EVL, [Condition]}.
+class VPReductionEVLRecipe : public VPSingleDefRecipe {
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fhahn wrote:

I think we need to also add support for the new recipe to type inference in VPlanAnalysis.cpp

https://github.com/llvm/llvm-project/pull/90184