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      1 //===-------- LegalizeTypesGeneric.cpp - Generic type legalization --------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file implements generic type expansion and splitting for LegalizeTypes.
     11 // The routines here perform legalization when the details of the type (such as
     12 // whether it is an integer or a float) do not matter.
     13 // Expansion is the act of changing a computation in an illegal type to be a
     14 // computation in two identical registers of a smaller type.  The Lo/Hi part
     15 // is required to be stored first in memory on little/big-endian machines.
     16 // Splitting is the act of changing a computation in an illegal type to be a
     17 // computation in two not necessarily identical registers of a smaller type.
     18 // There are no requirements on how the type is represented in memory.
     19 //
     20 //===----------------------------------------------------------------------===//
     21 
     22 #include "LegalizeTypes.h"
     23 #include "llvm/IR/DataLayout.h"
     24 using namespace llvm;
     25 
     26 #define DEBUG_TYPE "legalize-types"
     27 
     28 //===----------------------------------------------------------------------===//
     29 // Generic Result Expansion.
     30 //===----------------------------------------------------------------------===//
     31 
     32 // These routines assume that the Lo/Hi part is stored first in memory on
     33 // little/big-endian machines, followed by the Hi/Lo part.  This means that
     34 // they cannot be used as is on vectors, for which Lo is always stored first.
     35 void DAGTypeLegalizer::ExpandRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
     36                                               SDValue &Lo, SDValue &Hi) {
     37   SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
     38   GetExpandedOp(Op, Lo, Hi);
     39 }
     40 
     41 void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) {
     42   EVT OutVT = N->getValueType(0);
     43   EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT);
     44   SDValue InOp = N->getOperand(0);
     45   EVT InVT = InOp.getValueType();
     46   SDLoc dl(N);
     47 
     48   // Handle some special cases efficiently.
     49   switch (getTypeAction(InVT)) {
     50     case TargetLowering::TypeLegal:
     51     case TargetLowering::TypePromoteInteger:
     52       break;
     53     case TargetLowering::TypeSoftenFloat:
     54       // Convert the integer operand instead.
     55       SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
     56       Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
     57       Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
     58       return;
     59     case TargetLowering::TypeExpandInteger:
     60     case TargetLowering::TypeExpandFloat:
     61       // Convert the expanded pieces of the input.
     62       GetExpandedOp(InOp, Lo, Hi);
     63       if (TLI.hasBigEndianPartOrdering(InVT) !=
     64           TLI.hasBigEndianPartOrdering(OutVT))
     65         std::swap(Lo, Hi);
     66       Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
     67       Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
     68       return;
     69     case TargetLowering::TypeSplitVector:
     70       GetSplitVector(InOp, Lo, Hi);
     71       if (TLI.hasBigEndianPartOrdering(OutVT))
     72         std::swap(Lo, Hi);
     73       Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
     74       Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
     75       return;
     76     case TargetLowering::TypeScalarizeVector:
     77       // Convert the element instead.
     78       SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
     79       Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
     80       Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
     81       return;
     82     case TargetLowering::TypeWidenVector: {
     83       assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST");
     84       InOp = GetWidenedVector(InOp);
     85       EVT LoVT, HiVT;
     86       std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(InVT);
     87       std::tie(Lo, Hi) = DAG.SplitVector(InOp, dl, LoVT, HiVT);
     88       if (TLI.hasBigEndianPartOrdering(OutVT))
     89         std::swap(Lo, Hi);
     90       Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
     91       Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
     92       return;
     93     }
     94   }
     95 
     96   if (InVT.isVector() && OutVT.isInteger()) {
     97     // Handle cases like i64 = BITCAST v1i64 on x86, where the operand
     98     // is legal but the result is not.
     99     unsigned NumElems = 2;
    100     EVT ElemVT = NOutVT;
    101     EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
    102 
    103     // If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
    104     while (!isTypeLegal(NVT)) {
    105       unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
    106       // If the element size is smaller than byte, bail.
    107       if (NewSizeInBits < 8)
    108         break;
    109       NumElems *= 2;
    110       ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
    111       NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
    112     }
    113 
    114     if (isTypeLegal(NVT)) {
    115       SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
    116 
    117       SmallVector<SDValue, 8> Vals;
    118       for (unsigned i = 0; i < NumElems; ++i)
    119         Vals.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemVT,
    120                                    CastInOp, DAG.getConstant(i,
    121                                              TLI.getVectorIdxTy())));
    122 
    123       // Build Lo, Hi pair by pairing extracted elements if needed.
    124       unsigned Slot = 0;
    125       for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
    126         // Each iteration will BUILD_PAIR two nodes and append the result until
    127         // there are only two nodes left, i.e. Lo and Hi.
    128         SDValue LHS = Vals[Slot];
    129         SDValue RHS = Vals[Slot + 1];
    130 
    131         if (TLI.isBigEndian())
    132           std::swap(LHS, RHS);
    133 
    134         Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
    135                                    EVT::getIntegerVT(
    136                                      *DAG.getContext(),
    137                                      LHS.getValueType().getSizeInBits() << 1),
    138                                    LHS, RHS));
    139       }
    140       Lo = Vals[Slot++];
    141       Hi = Vals[Slot++];
    142 
    143       if (TLI.isBigEndian())
    144         std::swap(Lo, Hi);
    145 
    146       return;
    147     }
    148   }
    149 
    150   // Lower the bit-convert to a store/load from the stack.
    151   assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
    152 
    153   // Create the stack frame object.  Make sure it is aligned for both
    154   // the source and expanded destination types.
    155   unsigned Alignment =
    156     TLI.getDataLayout()->getPrefTypeAlignment(NOutVT.
    157                                               getTypeForEVT(*DAG.getContext()));
    158   SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
    159   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
    160   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
    161 
    162   // Emit a store to the stack slot.
    163   SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo,
    164                                false, false, 0);
    165 
    166   // Load the first half from the stack slot.
    167   Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo,
    168                    false, false, false, 0);
    169 
    170   // Increment the pointer to the other half.
    171   unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
    172   StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
    173                          DAG.getConstant(IncrementSize,
    174                                          StackPtr.getValueType()));
    175 
    176   // Load the second half from the stack slot.
    177   Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
    178                    PtrInfo.getWithOffset(IncrementSize), false,
    179                    false, false, MinAlign(Alignment, IncrementSize));
    180 
    181   // Handle endianness of the load.
    182   if (TLI.hasBigEndianPartOrdering(OutVT))
    183     std::swap(Lo, Hi);
    184 }
    185 
    186 void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
    187                                             SDValue &Hi) {
    188   // Return the operands.
    189   Lo = N->getOperand(0);
    190   Hi = N->getOperand(1);
    191 }
    192 
    193 void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
    194                                                  SDValue &Hi) {
    195   GetExpandedOp(N->getOperand(0), Lo, Hi);
    196   SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
    197                    Hi : Lo;
    198 
    199   assert(Part.getValueType() == N->getValueType(0) &&
    200          "Type twice as big as expanded type not itself expanded!");
    201 
    202   GetPairElements(Part, Lo, Hi);
    203 }
    204 
    205 void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
    206                                                     SDValue &Hi) {
    207   SDValue OldVec = N->getOperand(0);
    208   unsigned OldElts = OldVec.getValueType().getVectorNumElements();
    209   EVT OldEltVT = OldVec.getValueType().getVectorElementType();
    210   SDLoc dl(N);
    211 
    212   // Convert to a vector of the expanded element type, for example
    213   // <3 x i64> -> <6 x i32>.
    214   EVT OldVT = N->getValueType(0);
    215   EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
    216 
    217   if (OldVT != OldEltVT) {
    218     // The result of EXTRACT_VECTOR_ELT may be larger than the element type of
    219     // the input vector.  If so, extend the elements of the input vector to the
    220     // same bitwidth as the result before expanding.
    221     assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
    222     EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
    223     OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
    224   }
    225 
    226   SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
    227                                EVT::getVectorVT(*DAG.getContext(),
    228                                                 NewVT, 2*OldElts),
    229                                OldVec);
    230 
    231   // Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
    232   SDValue Idx = N->getOperand(1);
    233 
    234   Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
    235   Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
    236 
    237   Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
    238                     DAG.getConstant(1, Idx.getValueType()));
    239   Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
    240 
    241   if (TLI.isBigEndian())
    242     std::swap(Lo, Hi);
    243 }
    244 
    245 void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
    246                                             SDValue &Hi) {
    247   assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
    248   SDLoc dl(N);
    249 
    250   LoadSDNode *LD = cast<LoadSDNode>(N);
    251   EVT ValueVT = LD->getValueType(0);
    252   EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
    253   SDValue Chain = LD->getChain();
    254   SDValue Ptr = LD->getBasePtr();
    255   unsigned Alignment = LD->getAlignment();
    256   bool isVolatile = LD->isVolatile();
    257   bool isNonTemporal = LD->isNonTemporal();
    258   bool isInvariant = LD->isInvariant();
    259   const MDNode *TBAAInfo = LD->getTBAAInfo();
    260 
    261   assert(NVT.isByteSized() && "Expanded type not byte sized!");
    262 
    263   Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
    264                    isVolatile, isNonTemporal, isInvariant, Alignment,
    265                    TBAAInfo);
    266 
    267   // Increment the pointer to the other half.
    268   unsigned IncrementSize = NVT.getSizeInBits() / 8;
    269   Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    270                     DAG.getConstant(IncrementSize, Ptr.getValueType()));
    271   Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
    272                    LD->getPointerInfo().getWithOffset(IncrementSize),
    273                    isVolatile, isNonTemporal, isInvariant,
    274                    MinAlign(Alignment, IncrementSize), TBAAInfo);
    275 
    276   // Build a factor node to remember that this load is independent of the
    277   // other one.
    278   Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
    279                       Hi.getValue(1));
    280 
    281   // Handle endianness of the load.
    282   if (TLI.hasBigEndianPartOrdering(ValueVT))
    283     std::swap(Lo, Hi);
    284 
    285   // Modified the chain - switch anything that used the old chain to use
    286   // the new one.
    287   ReplaceValueWith(SDValue(N, 1), Chain);
    288 }
    289 
    290 void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
    291   EVT OVT = N->getValueType(0);
    292   EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT);
    293   SDValue Chain = N->getOperand(0);
    294   SDValue Ptr = N->getOperand(1);
    295   SDLoc dl(N);
    296   const unsigned Align = N->getConstantOperandVal(3);
    297 
    298   Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align);
    299   Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0);
    300 
    301   // Handle endianness of the load.
    302   if (TLI.hasBigEndianPartOrdering(OVT))
    303     std::swap(Lo, Hi);
    304 
    305   // Modified the chain - switch anything that used the old chain to use
    306   // the new one.
    307   ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
    308 }
    309 
    310 
    311 //===--------------------------------------------------------------------===//
    312 // Generic Operand Expansion.
    313 //===--------------------------------------------------------------------===//
    314 
    315 void DAGTypeLegalizer::IntegerToVector(SDValue Op, unsigned NumElements,
    316                                        SmallVectorImpl<SDValue> &Ops,
    317                                        EVT EltVT) {
    318   assert(Op.getValueType().isInteger());
    319   SDLoc DL(Op);
    320   SDValue Parts[2];
    321 
    322   if (NumElements > 1) {
    323     NumElements >>= 1;
    324     SplitInteger(Op, Parts[0], Parts[1]);
    325       if (TLI.isBigEndian())
    326         std::swap(Parts[0], Parts[1]);
    327     IntegerToVector(Parts[0], NumElements, Ops, EltVT);
    328     IntegerToVector(Parts[1], NumElements, Ops, EltVT);
    329   } else {
    330     Ops.push_back(DAG.getNode(ISD::BITCAST, DL, EltVT, Op));
    331   }
    332 }
    333 
    334 SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
    335   SDLoc dl(N);
    336   if (N->getValueType(0).isVector()) {
    337     // An illegal expanding type is being converted to a legal vector type.
    338     // Make a two element vector out of the expanded parts and convert that
    339     // instead, but only if the new vector type is legal (otherwise there
    340     // is no point, and it might create expansion loops).  For example, on
    341     // x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
    342     //
    343     // FIXME: I'm not sure why we are first trying to split the input into
    344     // a 2 element vector, so I'm leaving it here to maintain the current
    345     // behavior.
    346     unsigned NumElts = 2;
    347     EVT OVT = N->getOperand(0).getValueType();
    348     EVT NVT = EVT::getVectorVT(*DAG.getContext(),
    349                                TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
    350                                NumElts);
    351     if (!isTypeLegal(NVT)) {
    352       // If we can't find a legal type by splitting the integer in half,
    353       // then we can use the node's value type.
    354       NumElts = N->getValueType(0).getVectorNumElements();
    355       NVT = N->getValueType(0);
    356     }
    357 
    358     SmallVector<SDValue, 8> Ops;
    359     IntegerToVector(N->getOperand(0), NumElts, Ops, NVT.getVectorElementType());
    360 
    361     SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT,
    362                               makeArrayRef(Ops.data(), NumElts));
    363     return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
    364   }
    365 
    366   // Otherwise, store to a temporary and load out again as the new type.
    367   return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
    368 }
    369 
    370 SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
    371   // The vector type is legal but the element type needs expansion.
    372   EVT VecVT = N->getValueType(0);
    373   unsigned NumElts = VecVT.getVectorNumElements();
    374   EVT OldVT = N->getOperand(0).getValueType();
    375   EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
    376   SDLoc dl(N);
    377 
    378   assert(OldVT == VecVT.getVectorElementType() &&
    379          "BUILD_VECTOR operand type doesn't match vector element type!");
    380 
    381   // Build a vector of twice the length out of the expanded elements.
    382   // For example <3 x i64> -> <6 x i32>.
    383   std::vector<SDValue> NewElts;
    384   NewElts.reserve(NumElts*2);
    385 
    386   for (unsigned i = 0; i < NumElts; ++i) {
    387     SDValue Lo, Hi;
    388     GetExpandedOp(N->getOperand(i), Lo, Hi);
    389     if (TLI.isBigEndian())
    390       std::swap(Lo, Hi);
    391     NewElts.push_back(Lo);
    392     NewElts.push_back(Hi);
    393   }
    394 
    395   SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
    396                                EVT::getVectorVT(*DAG.getContext(),
    397                                                 NewVT, NewElts.size()),
    398                                NewElts);
    399 
    400   // Convert the new vector to the old vector type.
    401   return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
    402 }
    403 
    404 SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
    405   SDValue Lo, Hi;
    406   GetExpandedOp(N->getOperand(0), Lo, Hi);
    407   return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
    408 }
    409 
    410 SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
    411   // The vector type is legal but the element type needs expansion.
    412   EVT VecVT = N->getValueType(0);
    413   unsigned NumElts = VecVT.getVectorNumElements();
    414   SDLoc dl(N);
    415 
    416   SDValue Val = N->getOperand(1);
    417   EVT OldEVT = Val.getValueType();
    418   EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
    419 
    420   assert(OldEVT == VecVT.getVectorElementType() &&
    421          "Inserted element type doesn't match vector element type!");
    422 
    423   // Bitconvert to a vector of twice the length with elements of the expanded
    424   // type, insert the expanded vector elements, and then convert back.
    425   EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
    426   SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
    427                                NewVecVT, N->getOperand(0));
    428 
    429   SDValue Lo, Hi;
    430   GetExpandedOp(Val, Lo, Hi);
    431   if (TLI.isBigEndian())
    432     std::swap(Lo, Hi);
    433 
    434   SDValue Idx = N->getOperand(2);
    435   Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
    436   NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
    437   Idx = DAG.getNode(ISD::ADD, dl,
    438                     Idx.getValueType(), Idx,
    439                     DAG.getConstant(1, Idx.getValueType()));
    440   NewVec =  DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
    441 
    442   // Convert the new vector to the old vector type.
    443   return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
    444 }
    445 
    446 SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
    447   SDLoc dl(N);
    448   EVT VT = N->getValueType(0);
    449   assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
    450          "SCALAR_TO_VECTOR operand type doesn't match vector element type!");
    451   unsigned NumElts = VT.getVectorNumElements();
    452   SmallVector<SDValue, 16> Ops(NumElts);
    453   Ops[0] = N->getOperand(0);
    454   SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
    455   for (unsigned i = 1; i < NumElts; ++i)
    456     Ops[i] = UndefVal;
    457   return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
    458 }
    459 
    460 SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
    461   assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
    462   assert(OpNo == 1 && "Can only expand the stored value so far");
    463   SDLoc dl(N);
    464 
    465   StoreSDNode *St = cast<StoreSDNode>(N);
    466   EVT ValueVT = St->getValue().getValueType();
    467   EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
    468   SDValue Chain = St->getChain();
    469   SDValue Ptr = St->getBasePtr();
    470   unsigned Alignment = St->getAlignment();
    471   bool isVolatile = St->isVolatile();
    472   bool isNonTemporal = St->isNonTemporal();
    473   const MDNode *TBAAInfo = St->getTBAAInfo();
    474 
    475   assert(NVT.isByteSized() && "Expanded type not byte sized!");
    476   unsigned IncrementSize = NVT.getSizeInBits() / 8;
    477 
    478   SDValue Lo, Hi;
    479   GetExpandedOp(St->getValue(), Lo, Hi);
    480 
    481   if (TLI.hasBigEndianPartOrdering(ValueVT))
    482     std::swap(Lo, Hi);
    483 
    484   Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
    485                     isVolatile, isNonTemporal, Alignment, TBAAInfo);
    486 
    487   Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    488                     DAG.getConstant(IncrementSize, Ptr.getValueType()));
    489   Hi = DAG.getStore(Chain, dl, Hi, Ptr,
    490                     St->getPointerInfo().getWithOffset(IncrementSize),
    491                     isVolatile, isNonTemporal,
    492                     MinAlign(Alignment, IncrementSize), TBAAInfo);
    493 
    494   return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
    495 }
    496 
    497 
    498 //===--------------------------------------------------------------------===//
    499 // Generic Result Splitting.
    500 //===--------------------------------------------------------------------===//
    501 
    502 // Be careful to make no assumptions about which of Lo/Hi is stored first in
    503 // memory (for vectors it is always Lo first followed by Hi in the following
    504 // bytes; for integers and floats it is Lo first if and only if the machine is
    505 // little-endian).
    506 
    507 void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
    508                                              SDValue &Lo, SDValue &Hi) {
    509   SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
    510   GetSplitOp(Op, Lo, Hi);
    511 }
    512 
    513 void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
    514                                        SDValue &Hi) {
    515   SDValue LL, LH, RL, RH, CL, CH;
    516   SDLoc dl(N);
    517   GetSplitOp(N->getOperand(1), LL, LH);
    518   GetSplitOp(N->getOperand(2), RL, RH);
    519 
    520   SDValue Cond = N->getOperand(0);
    521   CL = CH = Cond;
    522   if (Cond.getValueType().isVector()) {
    523     // Check if there are already splitted versions of the vector available and
    524     // use those instead of splitting the mask operand again.
    525     if (getTypeAction(Cond.getValueType()) == TargetLowering::TypeSplitVector)
    526       GetSplitVector(Cond, CL, CH);
    527     else
    528       std::tie(CL, CH) = DAG.SplitVector(Cond, dl);
    529   }
    530 
    531   Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
    532   Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
    533 }
    534 
    535 void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
    536                                           SDValue &Hi) {
    537   SDValue LL, LH, RL, RH;
    538   SDLoc dl(N);
    539   GetSplitOp(N->getOperand(2), LL, LH);
    540   GetSplitOp(N->getOperand(3), RL, RH);
    541 
    542   Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
    543                    N->getOperand(1), LL, RL, N->getOperand(4));
    544   Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
    545                    N->getOperand(1), LH, RH, N->getOperand(4));
    546 }
    547 
    548 void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
    549   EVT LoVT, HiVT;
    550   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
    551   Lo = DAG.getUNDEF(LoVT);
    552   Hi = DAG.getUNDEF(HiVT);
    553 }
    554