[llvm] [TTI][RISCV] Deduplicate type-based VP costing (PR #115983)

[Luke Lau via llvm-commits]

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@@ -1563,6 +1563,67 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
     if (Intrinsic::isTargetIntrinsic(IID))
       return TargetTransformInfo::TCC_Basic;
 
+    // VP Intrinsics should have the same cost as their non-vp counterpart.
+    // TODO: Adjust the cost to make the vp intrinsic cheaper than its non-vp
+    // counterpart when the vector length argument is smaller than the maximum
+    // vector length.
+    // TODO: Support other kinds of VPIntrinsics
+    if (VPIntrinsic::isVPIntrinsic(ICA.getID())) {
+      std::optional<unsigned> FOp =
+          VPIntrinsic::getFunctionalOpcodeForVP(ICA.getID());
+      if (FOp) {
+        if (ICA.getID() == Intrinsic::vp_load) {
+          Align Alignment;
+          if (auto *VPI = dyn_cast_or_null<VPIntrinsic>(ICA.getInst()))
+            Alignment = VPI->getPointerAlignment().valueOrOne();
+          unsigned AS = 0;
+          if (ICA.getArgTypes().size() > 1)
+            if (auto *PtrTy = dyn_cast<PointerType>(ICA.getArgTypes()[0]))
+              AS = PtrTy->getAddressSpace();
+          return thisT()->getMemoryOpCost(*FOp, ICA.getReturnType(), Alignment,
+                                          AS, CostKind);
+        }
+        if (ICA.getID() == Intrinsic::vp_store) {
+          Align Alignment;
+          if (auto *VPI = dyn_cast_or_null<VPIntrinsic>(ICA.getInst()))
+            Alignment = VPI->getPointerAlignment().valueOrOne();
+          unsigned AS = 0;
+          if (ICA.getArgTypes().size() >= 2)
+            if (auto *PtrTy = dyn_cast<PointerType>(ICA.getArgTypes()[1]))
+              AS = PtrTy->getAddressSpace();
+          return thisT()->getMemoryOpCost(*FOp, ICA.getArgTypes()[0], Alignment,
+                                          AS, CostKind);
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lukel97 wrote:

Good point. This is from the existing code though so the non type-based cost would have been incorrect anyway

https://github.com/llvm/llvm-project/pull/115983