[llvm] [TTI][RISCV] Deduplicate type-based VP costing of VPReduction (PR #117708)

[Elvis Wang via llvm-commits]

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@@ -1647,6 +1647,38 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
                                                UI->getPredicate(), CostKind);
           }
         }
+        if (VPReductionIntrinsic::isVPReduction(ICA.getID())) {
+          std::optional<Intrinsic::ID> RedID =
+              VPIntrinsic::getFunctionalIntrinsicIDForVP(ICA.getID());
+          assert(RedID.has_value());
+          switch (ICA.getID()) {
+          case Intrinsic::vp_reduce_add:
+          case Intrinsic::vp_reduce_fadd:
+          case Intrinsic::vp_reduce_mul:
+          case Intrinsic::vp_reduce_fmul:
+          case Intrinsic::vp_reduce_and:
+          case Intrinsic::vp_reduce_or:
+          case Intrinsic::vp_reduce_xor: {
+            unsigned RedOp = getArithmeticReductionInstruction(*RedID);
+            return thisT()->getArithmeticReductionCost(
+                RedOp, cast<VectorType>(ICA.getArgTypes()[1]), ICA.getFlags(),
----------------
ElvisWang123 wrote:

You can find that the type-based vp reductions were supported in #115983.  [link](https://github.com/llvm/llvm-project/blob/93f7398bdba9d1547df21156db4d5393f0ab5ec8/llvm/include/llvm/CodeGen/BasicTTIImpl.h#L1665)

I think you only need to remove `vp_reduce_*` in the RISCVTTI.

https://github.com/llvm/llvm-project/pull/117708