[llvm] [VPlan] Impl VPlan-based pattern match for ExtendedRed and MulAccRed (PR #113903)

[Florian Hahn via llvm-commits]

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@@ -272,6 +272,14 @@ Type *VPTypeAnalysis::inferScalarType(const VPValue *V) {
             // TODO: Use info from interleave group.
             return V->getUnderlyingValue()->getType();
           })
+          .Case<VPExtendedReductionRecipe>(
+              [](const VPExtendedReductionRecipe *R) {
+                return R->getResultType();
+              })
+          .Case<VPMulAccumulateReductionRecipe>(
+              [](const VPMulAccumulateReductionRecipe *R) {
+                return R->getResultType();
+              })
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fhahn wrote:

The lambda should have used `const auto *R` (updated the suggestion) which is something that should be supported by the type switch, I think we use that feature in a number of places

https://github.com/llvm/llvm-project/pull/113903