[RISCV][CostModel] Add cost for @llvm.experimental.vp.splice

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp

@@ -1235,6 +1235,30 @@ RISCVTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
                                                   : RISCV::VMV_V_X,
                                               LT.second, CostKind);
   }
+  case Intrinsic::experimental_vp_splice: {
+    auto LT = getTypeLegalizationCost(RetTy);
+    SmallVector<unsigned, 2> Opcodes;
+    auto *Imm = cast<ConstantInt>(ICA.getInst()->getArgOperand(2));
+    if (Imm->isNegative())
+      Opcodes = {RISCV::VSLIDEDOWN_VI, RISCV::VSLIDEUP_VX};
+    else
+      Opcodes = {RISCV::VSLIDEDOWN_VX, RISCV::VSLIDEUP_VI};
+
+    if (!ST->hasVInstructions())
+      return InstructionCost::getInvalid();
+
+    if (LT.second.getScalarType() == MVT::i1) {
+      unsigned AddOpcodes[8] = {
+          RISCV::VMV1R_V, RISCV::VMV1R_V, RISCV::VMV_V_I,    RISCV::VMERGE_VIM,
+          RISCV::VMV_V_I, RISCV::VMV1R_V, RISCV::VMERGE_VIM, RISCV::VMSNE_VI};
+      return LT.first *
+                 (getRISCVInstructionCost(Opcodes, LT.second, CostKind) +
+                  getRISCVInstructionCost(AddOpcodes, LT.second, CostKind)) +
+             1;
+    }
+
+    return LT.first * getRISCVInstructionCost(Opcodes, LT.second, CostKind) + 1;
+  }
   }
 
   if (ST->hasVInstructions() && RetTy->isVectorTy()) {