[NFC] [Legalizer] Use common method for expanding fp-to-int operands

[steven.zhang]

LGTM as it makes sense. But hold on for several days to see if others have more comments.

[RKSimon]

LGTM

llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp

#endif
   case ISD::BUILD_VECTOR:    Res = ExpandOp_BUILD_VECTOR(N); break;
   case ISD::EXTRACT_ELEMENT: Res = ExpandOp_EXTRACT_ELEMENT(N); break;
 
   case ISD::BR_CC:      Res = ExpandFloatOp_BR_CC(N); break;
   case ISD::FCOPYSIGN:  Res = ExpandFloatOp_FCOPYSIGN(N); break;
   case ISD::STRICT_FP_ROUND:
   case ISD::FP_ROUND:   Res = ExpandFloatOp_FP_ROUND(N); break;
   case ISD::STRICT_FP_TO_SINT:
-  case ISD::FP_TO_SINT: Res = ExpandFloatOp_FP_TO_SINT(N); break;
   case ISD::STRICT_FP_TO_UINT:
-  case ISD::FP_TO_UINT: Res = ExpandFloatOp_FP_TO_UINT(N); break;
+  case ISD::FP_TO_SINT:
+  case ISD::FP_TO_UINT: Res = ExpandFloatOp_FP_TO_XINT(N); break;
   case ISD::LROUND:     Res = ExpandFloatOp_LROUND(N); break;
   case ISD::LLROUND:    Res = ExpandFloatOp_LLROUND(N); break;
   case ISD::LRINT:      Res = ExpandFloatOp_LRINT(N); break;
   case ISD::LLRINT:     Res = ExpandFloatOp_LLRINT(N); break;
   case ISD::SELECT_CC:  Res = ExpandFloatOp_SELECT_CC(N); break;
   case ISD::STRICT_FSETCC:
   case ISD::STRICT_FSETCCS:
   case ISD::SETCC:      Res = ExpandFloatOp_SETCC(N); break;
SDValue DAGTypeLegalizer::ExpandFloatOp_FP_ROUND(SDNode *N) {
   SDValue Expansion = DAG.getNode(ISD::STRICT_FP_ROUND, SDLoc(N),
                                   {N->getValueType(0), MVT::Other},
                                   {N->getOperand(0), Hi, N->getOperand(2)});
   ReplaceValueWith(SDValue(N, 1), Expansion.getValue(1));
   ReplaceValueWith(SDValue(N, 0), Expansion);
   return SDValue();
 }
 
-SDValue DAGTypeLegalizer::ExpandFloatOp_FP_TO_SINT(SDNode *N) {
-  EVT RVT = N->getValueType(0);
-  SDLoc dl(N);
-
-  bool IsStrict = N->isStrictFPOpcode();
-  SDValue Op = N->getOperand(IsStrict ? 1 : 0);
-  SDValue Chain = IsStrict ? N->getOperand(0) : SDValue();
-  RTLIB::Libcall LC = RTLIB::getFPTOSINT(Op.getValueType(), RVT);
-  assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported FP_TO_SINT!");
-  TargetLowering::MakeLibCallOptions CallOptions;
-  std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RVT, Op,
-                                                    CallOptions, dl, Chain);
-  if (!IsStrict)
-    return Tmp.first;
-
-  ReplaceValueWith(SDValue(N, 1), Tmp.second);
-  ReplaceValueWith(SDValue(N, 0), Tmp.first);
-  return SDValue();
-}
-
-SDValue DAGTypeLegalizer::ExpandFloatOp_FP_TO_UINT(SDNode *N) {
+SDValue DAGTypeLegalizer::ExpandFloatOp_FP_TO_XINT(SDNode *N) {
   EVT RVT = N->getValueType(0);
   SDLoc dl(N);
 
   bool IsStrict = N->isStrictFPOpcode();
+  bool Signed = N->getOpcode() == ISD::FP_TO_SINT ||
+                N->getOpcode() == ISD::STRICT_FP_TO_SINT;
   SDValue Op = N->getOperand(IsStrict ? 1 : 0);
   SDValue Chain = IsStrict ? N->getOperand(0) : SDValue();
-  RTLIB::Libcall LC = RTLIB::getFPTOUINT(Op.getValueType(), RVT);
-  assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported FP_TO_UINT!");
+  RTLIB::Libcall LC = Signed ? RTLIB::getFPTOSINT(Op.getValueType(), RVT)
+                             : RTLIB::getFPTOUINT(Op.getValueType(), RVT);
+  assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unsupported FP_TO_XINT!");
   TargetLowering::MakeLibCallOptions CallOptions;
-  std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RVT, Op,
-                                                    CallOptions, dl, Chain);
+  std::pair<SDValue, SDValue> Tmp =
+      TLI.makeLibCall(DAG, LC, RVT, Op, CallOptions, dl, Chain);
   if (!IsStrict)
     return Tmp.first;
 
   ReplaceValueWith(SDValue(N, 1), Tmp.second);
   ReplaceValueWith(SDValue(N, 0), Tmp.first);
   return SDValue();
 }
 

llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h

private:
   void ExpandFloatRes_LOAD      (SDNode *N, SDValue &Lo, SDValue &Hi);
   void ExpandFloatRes_XINT_TO_FP(SDNode *N, SDValue &Lo, SDValue &Hi);
 
   // Float Operand Expansion.
   bool ExpandFloatOperand(SDNode *N, unsigned OpNo);
   SDValue ExpandFloatOp_BR_CC(SDNode *N);
   SDValue ExpandFloatOp_FCOPYSIGN(SDNode *N);
   SDValue ExpandFloatOp_FP_ROUND(SDNode *N);
-  SDValue ExpandFloatOp_FP_TO_SINT(SDNode *N);
-  SDValue ExpandFloatOp_FP_TO_UINT(SDNode *N);
+  SDValue ExpandFloatOp_FP_TO_XINT(SDNode *N);
   SDValue ExpandFloatOp_LROUND(SDNode *N);
   SDValue ExpandFloatOp_LLROUND(SDNode *N);
   SDValue ExpandFloatOp_LRINT(SDNode *N);
   SDValue ExpandFloatOp_LLRINT(SDNode *N);
   SDValue ExpandFloatOp_SELECT_CC(SDNode *N);
   SDValue ExpandFloatOp_SETCC(SDNode *N);
   SDValue ExpandFloatOp_STORE(SDNode *N, unsigned OpNo);