[llvm] [LV] Support EVL for partial reduction and VPExpressionRecipe. (PR #205741)

[Luke Lau via llvm-commits]

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@@ -338,6 +372,10 @@ void VPlanTransforms::optimizeEVLMasks(VPlan &Plan) {
     OldRecipes.push_back(R);
   }
 
+  // If the expression recipe is the only user of the header mask, delete it
+  // explicitly.
+  vputils::recursivelyDeleteDeadRecipes(HeaderMask);
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lukel97 wrote:

Should this be moved into optimizeExpressionRecipeToEVL?

https://github.com/llvm/llvm-project/pull/205741