[Target] Use getConstantOperand (NFC)

Author: kazutakahirata

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

@@ -7726,8 +7726,7 @@ SDValue SITargetLowering::lowerImage(SDValue Op,
     }
   }
 
-  unsigned CPol = cast<ConstantSDNode>(
-      Op.getOperand(ArgOffset + Intr->CachePolicyIndex))->getZExtValue();
+  unsigned CPol = Op.getConstantOperandVal(ArgOffset + Intr->CachePolicyIndex);
   if (BaseOpcode->Atomic)
     CPol |= AMDGPU::CPol::GLC; // TODO no-return optimization
   if (CPol & ~((IsGFX12Plus ? AMDGPU::CPol::ALL : AMDGPU::CPol::ALL_pregfx12) |

llvm/lib/Target/ARM/ARMISelLowering.cpp

@@ -4068,9 +4068,7 @@ SDValue ARMTargetLowering::LowerEH_SJLJ_SETUP_DISPATCH(SDValue Op,
 SDValue ARMTargetLowering::LowerINTRINSIC_VOID(
     SDValue Op, SelectionDAG &DAG, const ARMSubtarget *Subtarget) const {
   unsigned IntNo =
-      cast<ConstantSDNode>(
-          Op.getOperand(Op.getOperand(0).getValueType() == MVT::Other))
-          ->getZExtValue();
+      Op.getConstantOperandVal(Op.getOperand(0).getValueType() == MVT::Other);
   switch (IntNo) {
     default:
       return SDValue();  // Don't custom lower most intrinsics.

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

@@ -11253,9 +11253,9 @@ SDValue PPCTargetLowering::LowerIS_FPCLASS(SDValue Op,
                                            SelectionDAG &DAG) const {
   assert(Subtarget.hasP9Vector() && "Test data class requires Power9");
   SDValue LHS = Op.getOperand(0);
-  const auto *RHS = cast<ConstantSDNode>(Op.getOperand(1));
+  uint64_t RHSC = Op.getConstantOperandVal(1);
   SDLoc Dl(Op);
-  FPClassTest Category = static_cast<FPClassTest>(RHS->getZExtValue());
+  FPClassTest Category = static_cast<FPClassTest>(RHSC);
   return getDataClassTest(LHS, Category, Dl, DAG, Subtarget);
 }
 

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -831,8 +831,7 @@ void RISCVDAGToDAGISel::selectSF_VC_X_SE(SDNode *Node) {
          "Unexpected vsetvli intrinsic");
 
   // imm, imm, imm, simm5/scalar, sew, log2lmul, vl
-  auto *SewSDNode = cast<ConstantSDNode>(Node->getOperand(6));
-  unsigned Log2SEW = Log2_32(SewSDNode->getZExtValue());
+  unsigned Log2SEW = Log2_32(Node->getConstantOperandVal(6));
   SDValue SEWOp =
       CurDAG->getTargetConstant(Log2SEW, DL, Subtarget->getXLenVT());
   SmallVector<SDValue, 8> Operands = {Node->getOperand(2), Node->getOperand(3),