[RISCV][TTI] Scale the cost of intrinsic umin/umax/smin/smax with LMUL (#87245)

Use the return type to measure the LMUL size for throughput/latency cost

Author: arcbbb

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp

@@ -810,9 +810,27 @@ RISCVTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
   case Intrinsic::smin:
   case Intrinsic::smax: {
     auto LT = getTypeLegalizationCost(RetTy);
-    if ((ST->hasVInstructions() && LT.second.isVector()) ||
-        (LT.second.isScalarInteger() && ST->hasStdExtZbb()))
+    if (LT.second.isScalarInteger() && ST->hasStdExtZbb())
       return LT.first;
+
+    if (ST->hasVInstructions() && LT.second.isVector()) {
+      unsigned Op;
+      switch (ICA.getID()) {
+      case Intrinsic::umin:
+        Op = RISCV::VMINU_VV;
+        break;
+      case Intrinsic::umax:
+        Op = RISCV::VMAXU_VV;
+        break;
+      case Intrinsic::smin:
+        Op = RISCV::VMIN_VV;
+        break;
+      case Intrinsic::smax:
+        Op = RISCV::VMAX_VV;
+        break;
+      }
+      return LT.first * getRISCVInstructionCost(Op, LT.second, CostKind);
+    }
     break;
   }
   case Intrinsic::sadd_sat: