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      1 //===-- LegalizeDAG.cpp - Implement SelectionDAG::Legalize ----------------===//
      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 the SelectionDAG::Legalize method.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "llvm/CodeGen/SelectionDAG.h"
     15 #include "llvm/ADT/SmallPtrSet.h"
     16 #include "llvm/ADT/SmallSet.h"
     17 #include "llvm/ADT/SmallVector.h"
     18 #include "llvm/ADT/Triple.h"
     19 #include "llvm/CodeGen/Analysis.h"
     20 #include "llvm/CodeGen/MachineFunction.h"
     21 #include "llvm/CodeGen/MachineJumpTableInfo.h"
     22 #include "llvm/IR/CallingConv.h"
     23 #include "llvm/IR/Constants.h"
     24 #include "llvm/IR/DataLayout.h"
     25 #include "llvm/IR/DebugInfo.h"
     26 #include "llvm/IR/DerivedTypes.h"
     27 #include "llvm/IR/Function.h"
     28 #include "llvm/IR/LLVMContext.h"
     29 #include "llvm/Support/Debug.h"
     30 #include "llvm/Support/ErrorHandling.h"
     31 #include "llvm/Support/MathExtras.h"
     32 #include "llvm/Support/raw_ostream.h"
     33 #include "llvm/Target/TargetFrameLowering.h"
     34 #include "llvm/Target/TargetLowering.h"
     35 #include "llvm/Target/TargetMachine.h"
     36 using namespace llvm;
     37 
     38 //===----------------------------------------------------------------------===//
     39 /// SelectionDAGLegalize - This takes an arbitrary SelectionDAG as input and
     40 /// hacks on it until the target machine can handle it.  This involves
     41 /// eliminating value sizes the machine cannot handle (promoting small sizes to
     42 /// large sizes or splitting up large values into small values) as well as
     43 /// eliminating operations the machine cannot handle.
     44 ///
     45 /// This code also does a small amount of optimization and recognition of idioms
     46 /// as part of its processing.  For example, if a target does not support a
     47 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
     48 /// will attempt merge setcc and brc instructions into brcc's.
     49 ///
     50 namespace {
     51 class SelectionDAGLegalize : public SelectionDAG::DAGUpdateListener {
     52   const TargetMachine &TM;
     53   const TargetLowering &TLI;
     54   SelectionDAG &DAG;
     55 
     56   /// LegalizePosition - The iterator for walking through the node list.
     57   SelectionDAG::allnodes_iterator LegalizePosition;
     58 
     59   /// LegalizedNodes - The set of nodes which have already been legalized.
     60   SmallPtrSet<SDNode *, 16> LegalizedNodes;
     61 
     62   EVT getSetCCResultType(EVT VT) const {
     63     return TLI.getSetCCResultType(*DAG.getContext(), VT);
     64   }
     65 
     66   // Libcall insertion helpers.
     67 
     68 public:
     69   explicit SelectionDAGLegalize(SelectionDAG &DAG);
     70 
     71   void LegalizeDAG();
     72 
     73 private:
     74   /// LegalizeOp - Legalizes the given operation.
     75   void LegalizeOp(SDNode *Node);
     76 
     77   SDValue OptimizeFloatStore(StoreSDNode *ST);
     78 
     79   void LegalizeLoadOps(SDNode *Node);
     80   void LegalizeStoreOps(SDNode *Node);
     81 
     82   /// PerformInsertVectorEltInMemory - Some target cannot handle a variable
     83   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
     84   /// is necessary to spill the vector being inserted into to memory, perform
     85   /// the insert there, and then read the result back.
     86   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val,
     87                                          SDValue Idx, SDLoc dl);
     88   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
     89                                   SDValue Idx, SDLoc dl);
     90 
     91   /// ShuffleWithNarrowerEltType - Return a vector shuffle operation which
     92   /// performs the same shuffe in terms of order or result bytes, but on a type
     93   /// whose vector element type is narrower than the original shuffle type.
     94   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
     95   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, SDLoc dl,
     96                                      SDValue N1, SDValue N2,
     97                                      ArrayRef<int> Mask) const;
     98 
     99   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
    100                              bool &NeedInvert, SDLoc dl);
    101 
    102   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
    103   SDValue ExpandLibCall(RTLIB::Libcall LC, EVT RetVT, const SDValue *Ops,
    104                         unsigned NumOps, bool isSigned, SDLoc dl);
    105 
    106   std::pair<SDValue, SDValue> ExpandChainLibCall(RTLIB::Libcall LC,
    107                                                  SDNode *Node, bool isSigned);
    108   SDValue ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
    109                           RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
    110                           RTLIB::Libcall Call_F128,
    111                           RTLIB::Libcall Call_PPCF128);
    112   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
    113                            RTLIB::Libcall Call_I8,
    114                            RTLIB::Libcall Call_I16,
    115                            RTLIB::Libcall Call_I32,
    116                            RTLIB::Libcall Call_I64,
    117                            RTLIB::Libcall Call_I128);
    118   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
    119   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
    120 
    121   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT, SDLoc dl);
    122   SDValue ExpandBUILD_VECTOR(SDNode *Node);
    123   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
    124   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
    125                                 SmallVectorImpl<SDValue> &Results);
    126   SDValue ExpandFCOPYSIGN(SDNode *Node);
    127   SDValue ExpandLegalINT_TO_FP(bool isSigned, SDValue LegalOp, EVT DestVT,
    128                                SDLoc dl);
    129   SDValue PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT, bool isSigned,
    130                                 SDLoc dl);
    131   SDValue PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT, bool isSigned,
    132                                 SDLoc dl);
    133 
    134   SDValue ExpandBSWAP(SDValue Op, SDLoc dl);
    135   SDValue ExpandBitCount(unsigned Opc, SDValue Op, SDLoc dl);
    136 
    137   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
    138   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
    139   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
    140 
    141   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
    142 
    143   std::pair<SDValue, SDValue> ExpandAtomic(SDNode *Node);
    144 
    145   void ExpandNode(SDNode *Node);
    146   void PromoteNode(SDNode *Node);
    147 
    148   void ForgetNode(SDNode *N) {
    149     LegalizedNodes.erase(N);
    150     if (LegalizePosition == SelectionDAG::allnodes_iterator(N))
    151       ++LegalizePosition;
    152   }
    153 
    154 public:
    155   // DAGUpdateListener implementation.
    156   void NodeDeleted(SDNode *N, SDNode *E) override {
    157     ForgetNode(N);
    158   }
    159   void NodeUpdated(SDNode *N) override {}
    160 
    161   // Node replacement helpers
    162   void ReplacedNode(SDNode *N) {
    163     if (N->use_empty()) {
    164       DAG.RemoveDeadNode(N);
    165     } else {
    166       ForgetNode(N);
    167     }
    168   }
    169   void ReplaceNode(SDNode *Old, SDNode *New) {
    170     DAG.ReplaceAllUsesWith(Old, New);
    171     ReplacedNode(Old);
    172   }
    173   void ReplaceNode(SDValue Old, SDValue New) {
    174     DAG.ReplaceAllUsesWith(Old, New);
    175     ReplacedNode(Old.getNode());
    176   }
    177   void ReplaceNode(SDNode *Old, const SDValue *New) {
    178     DAG.ReplaceAllUsesWith(Old, New);
    179     ReplacedNode(Old);
    180   }
    181 };
    182 }
    183 
    184 /// ShuffleWithNarrowerEltType - Return a vector shuffle operation which
    185 /// performs the same shuffe in terms of order or result bytes, but on a type
    186 /// whose vector element type is narrower than the original shuffle type.
    187 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
    188 SDValue
    189 SelectionDAGLegalize::ShuffleWithNarrowerEltType(EVT NVT, EVT VT,  SDLoc dl,
    190                                                  SDValue N1, SDValue N2,
    191                                                  ArrayRef<int> Mask) const {
    192   unsigned NumMaskElts = VT.getVectorNumElements();
    193   unsigned NumDestElts = NVT.getVectorNumElements();
    194   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
    195 
    196   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
    197 
    198   if (NumEltsGrowth == 1)
    199     return DAG.getVectorShuffle(NVT, dl, N1, N2, &Mask[0]);
    200 
    201   SmallVector<int, 8> NewMask;
    202   for (unsigned i = 0; i != NumMaskElts; ++i) {
    203     int Idx = Mask[i];
    204     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
    205       if (Idx < 0)
    206         NewMask.push_back(-1);
    207       else
    208         NewMask.push_back(Idx * NumEltsGrowth + j);
    209     }
    210   }
    211   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
    212   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
    213   return DAG.getVectorShuffle(NVT, dl, N1, N2, &NewMask[0]);
    214 }
    215 
    216 SelectionDAGLegalize::SelectionDAGLegalize(SelectionDAG &dag)
    217   : SelectionDAG::DAGUpdateListener(dag),
    218     TM(dag.getTarget()), TLI(dag.getTargetLoweringInfo()),
    219     DAG(dag) {
    220 }
    221 
    222 void SelectionDAGLegalize::LegalizeDAG() {
    223   DAG.AssignTopologicalOrder();
    224 
    225   // Visit all the nodes. We start in topological order, so that we see
    226   // nodes with their original operands intact. Legalization can produce
    227   // new nodes which may themselves need to be legalized. Iterate until all
    228   // nodes have been legalized.
    229   for (;;) {
    230     bool AnyLegalized = false;
    231     for (LegalizePosition = DAG.allnodes_end();
    232          LegalizePosition != DAG.allnodes_begin(); ) {
    233       --LegalizePosition;
    234 
    235       SDNode *N = LegalizePosition;
    236       if (LegalizedNodes.insert(N)) {
    237         AnyLegalized = true;
    238         LegalizeOp(N);
    239       }
    240     }
    241     if (!AnyLegalized)
    242       break;
    243 
    244   }
    245 
    246   // Remove dead nodes now.
    247   DAG.RemoveDeadNodes();
    248 }
    249 
    250 /// ExpandConstantFP - Expands the ConstantFP node to an integer constant or
    251 /// a load from the constant pool.
    252 SDValue
    253 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
    254   bool Extend = false;
    255   SDLoc dl(CFP);
    256 
    257   // If a FP immediate is precise when represented as a float and if the
    258   // target can do an extending load from float to double, we put it into
    259   // the constant pool as a float, even if it's is statically typed as a
    260   // double.  This shrinks FP constants and canonicalizes them for targets where
    261   // an FP extending load is the same cost as a normal load (such as on the x87
    262   // fp stack or PPC FP unit).
    263   EVT VT = CFP->getValueType(0);
    264   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
    265   if (!UseCP) {
    266     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
    267     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(),
    268                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
    269   }
    270 
    271   EVT OrigVT = VT;
    272   EVT SVT = VT;
    273   while (SVT != MVT::f32) {
    274     SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
    275     if (ConstantFPSDNode::isValueValidForType(SVT, CFP->getValueAPF()) &&
    276         // Only do this if the target has a native EXTLOAD instruction from
    277         // smaller type.
    278         TLI.isLoadExtLegal(ISD::EXTLOAD, SVT) &&
    279         TLI.ShouldShrinkFPConstant(OrigVT)) {
    280       Type *SType = SVT.getTypeForEVT(*DAG.getContext());
    281       LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
    282       VT = SVT;
    283       Extend = true;
    284     }
    285   }
    286 
    287   SDValue CPIdx = DAG.getConstantPool(LLVMC, TLI.getPointerTy());
    288   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
    289   if (Extend) {
    290     SDValue Result =
    291       DAG.getExtLoad(ISD::EXTLOAD, dl, OrigVT,
    292                      DAG.getEntryNode(),
    293                      CPIdx, MachinePointerInfo::getConstantPool(),
    294                      VT, false, false, Alignment);
    295     return Result;
    296   }
    297   SDValue Result =
    298     DAG.getLoad(OrigVT, dl, DAG.getEntryNode(), CPIdx,
    299                 MachinePointerInfo::getConstantPool(), false, false, false,
    300                 Alignment);
    301   return Result;
    302 }
    303 
    304 /// ExpandUnalignedStore - Expands an unaligned store to 2 half-size stores.
    305 static void ExpandUnalignedStore(StoreSDNode *ST, SelectionDAG &DAG,
    306                                  const TargetLowering &TLI,
    307                                  SelectionDAGLegalize *DAGLegalize) {
    308   assert(ST->getAddressingMode() == ISD::UNINDEXED &&
    309          "unaligned indexed stores not implemented!");
    310   SDValue Chain = ST->getChain();
    311   SDValue Ptr = ST->getBasePtr();
    312   SDValue Val = ST->getValue();
    313   EVT VT = Val.getValueType();
    314   int Alignment = ST->getAlignment();
    315   unsigned AS = ST->getAddressSpace();
    316 
    317   SDLoc dl(ST);
    318   if (ST->getMemoryVT().isFloatingPoint() ||
    319       ST->getMemoryVT().isVector()) {
    320     EVT intVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
    321     if (TLI.isTypeLegal(intVT)) {
    322       // Expand to a bitconvert of the value to the integer type of the
    323       // same size, then a (misaligned) int store.
    324       // FIXME: Does not handle truncating floating point stores!
    325       SDValue Result = DAG.getNode(ISD::BITCAST, dl, intVT, Val);
    326       Result = DAG.getStore(Chain, dl, Result, Ptr, ST->getPointerInfo(),
    327                            ST->isVolatile(), ST->isNonTemporal(), Alignment);
    328       DAGLegalize->ReplaceNode(SDValue(ST, 0), Result);
    329       return;
    330     }
    331     // Do a (aligned) store to a stack slot, then copy from the stack slot
    332     // to the final destination using (unaligned) integer loads and stores.
    333     EVT StoredVT = ST->getMemoryVT();
    334     MVT RegVT =
    335       TLI.getRegisterType(*DAG.getContext(),
    336                           EVT::getIntegerVT(*DAG.getContext(),
    337                                             StoredVT.getSizeInBits()));
    338     unsigned StoredBytes = StoredVT.getSizeInBits() / 8;
    339     unsigned RegBytes = RegVT.getSizeInBits() / 8;
    340     unsigned NumRegs = (StoredBytes + RegBytes - 1) / RegBytes;
    341 
    342     // Make sure the stack slot is also aligned for the register type.
    343     SDValue StackPtr = DAG.CreateStackTemporary(StoredVT, RegVT);
    344 
    345     // Perform the original store, only redirected to the stack slot.
    346     SDValue Store = DAG.getTruncStore(Chain, dl,
    347                                       Val, StackPtr, MachinePointerInfo(),
    348                                       StoredVT, false, false, 0);
    349     SDValue Increment = DAG.getConstant(RegBytes, TLI.getPointerTy(AS));
    350     SmallVector<SDValue, 8> Stores;
    351     unsigned Offset = 0;
    352 
    353     // Do all but one copies using the full register width.
    354     for (unsigned i = 1; i < NumRegs; i++) {
    355       // Load one integer register's worth from the stack slot.
    356       SDValue Load = DAG.getLoad(RegVT, dl, Store, StackPtr,
    357                                  MachinePointerInfo(),
    358                                  false, false, false, 0);
    359       // Store it to the final location.  Remember the store.
    360       Stores.push_back(DAG.getStore(Load.getValue(1), dl, Load, Ptr,
    361                                   ST->getPointerInfo().getWithOffset(Offset),
    362                                     ST->isVolatile(), ST->isNonTemporal(),
    363                                     MinAlign(ST->getAlignment(), Offset)));
    364       // Increment the pointers.
    365       Offset += RegBytes;
    366       StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
    367                              Increment);
    368       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, Increment);
    369     }
    370 
    371     // The last store may be partial.  Do a truncating store.  On big-endian
    372     // machines this requires an extending load from the stack slot to ensure
    373     // that the bits are in the right place.
    374     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(),
    375                                   8 * (StoredBytes - Offset));
    376 
    377     // Load from the stack slot.
    378     SDValue Load = DAG.getExtLoad(ISD::EXTLOAD, dl, RegVT, Store, StackPtr,
    379                                   MachinePointerInfo(),
    380                                   MemVT, false, false, 0);
    381 
    382     Stores.push_back(DAG.getTruncStore(Load.getValue(1), dl, Load, Ptr,
    383                                        ST->getPointerInfo()
    384                                          .getWithOffset(Offset),
    385                                        MemVT, ST->isVolatile(),
    386                                        ST->isNonTemporal(),
    387                                        MinAlign(ST->getAlignment(), Offset),
    388                                        ST->getTBAAInfo()));
    389     // The order of the stores doesn't matter - say it with a TokenFactor.
    390     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
    391     DAGLegalize->ReplaceNode(SDValue(ST, 0), Result);
    392     return;
    393   }
    394   assert(ST->getMemoryVT().isInteger() &&
    395          !ST->getMemoryVT().isVector() &&
    396          "Unaligned store of unknown type.");
    397   // Get the half-size VT
    398   EVT NewStoredVT = ST->getMemoryVT().getHalfSizedIntegerVT(*DAG.getContext());
    399   int NumBits = NewStoredVT.getSizeInBits();
    400   int IncrementSize = NumBits / 8;
    401 
    402   // Divide the stored value in two parts.
    403   SDValue ShiftAmount = DAG.getConstant(NumBits,
    404                                       TLI.getShiftAmountTy(Val.getValueType()));
    405   SDValue Lo = Val;
    406   SDValue Hi = DAG.getNode(ISD::SRL, dl, VT, Val, ShiftAmount);
    407 
    408   // Store the two parts
    409   SDValue Store1, Store2;
    410   Store1 = DAG.getTruncStore(Chain, dl, TLI.isLittleEndian()?Lo:Hi, Ptr,
    411                              ST->getPointerInfo(), NewStoredVT,
    412                              ST->isVolatile(), ST->isNonTemporal(), Alignment);
    413 
    414   Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    415                     DAG.getConstant(IncrementSize, TLI.getPointerTy(AS)));
    416   Alignment = MinAlign(Alignment, IncrementSize);
    417   Store2 = DAG.getTruncStore(Chain, dl, TLI.isLittleEndian()?Hi:Lo, Ptr,
    418                              ST->getPointerInfo().getWithOffset(IncrementSize),
    419                              NewStoredVT, ST->isVolatile(), ST->isNonTemporal(),
    420                              Alignment, ST->getTBAAInfo());
    421 
    422   SDValue Result =
    423     DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Store1, Store2);
    424   DAGLegalize->ReplaceNode(SDValue(ST, 0), Result);
    425 }
    426 
    427 /// ExpandUnalignedLoad - Expands an unaligned load to 2 half-size loads.
    428 static void
    429 ExpandUnalignedLoad(LoadSDNode *LD, SelectionDAG &DAG,
    430                     const TargetLowering &TLI,
    431                     SDValue &ValResult, SDValue &ChainResult) {
    432   assert(LD->getAddressingMode() == ISD::UNINDEXED &&
    433          "unaligned indexed loads not implemented!");
    434   SDValue Chain = LD->getChain();
    435   SDValue Ptr = LD->getBasePtr();
    436   EVT VT = LD->getValueType(0);
    437   EVT LoadedVT = LD->getMemoryVT();
    438   SDLoc dl(LD);
    439   if (VT.isFloatingPoint() || VT.isVector()) {
    440     EVT intVT = EVT::getIntegerVT(*DAG.getContext(), LoadedVT.getSizeInBits());
    441     if (TLI.isTypeLegal(intVT) && TLI.isTypeLegal(LoadedVT)) {
    442       // Expand to a (misaligned) integer load of the same size,
    443       // then bitconvert to floating point or vector.
    444       SDValue newLoad = DAG.getLoad(intVT, dl, Chain, Ptr,
    445                                     LD->getMemOperand());
    446       SDValue Result = DAG.getNode(ISD::BITCAST, dl, LoadedVT, newLoad);
    447       if (LoadedVT != VT)
    448         Result = DAG.getNode(VT.isFloatingPoint() ? ISD::FP_EXTEND :
    449                              ISD::ANY_EXTEND, dl, VT, Result);
    450 
    451       ValResult = Result;
    452       ChainResult = Chain;
    453       return;
    454     }
    455 
    456     // Copy the value to a (aligned) stack slot using (unaligned) integer
    457     // loads and stores, then do a (aligned) load from the stack slot.
    458     MVT RegVT = TLI.getRegisterType(*DAG.getContext(), intVT);
    459     unsigned LoadedBytes = LoadedVT.getSizeInBits() / 8;
    460     unsigned RegBytes = RegVT.getSizeInBits() / 8;
    461     unsigned NumRegs = (LoadedBytes + RegBytes - 1) / RegBytes;
    462 
    463     // Make sure the stack slot is also aligned for the register type.
    464     SDValue StackBase = DAG.CreateStackTemporary(LoadedVT, RegVT);
    465 
    466     SDValue Increment = DAG.getConstant(RegBytes, TLI.getPointerTy());
    467     SmallVector<SDValue, 8> Stores;
    468     SDValue StackPtr = StackBase;
    469     unsigned Offset = 0;
    470 
    471     // Do all but one copies using the full register width.
    472     for (unsigned i = 1; i < NumRegs; i++) {
    473       // Load one integer register's worth from the original location.
    474       SDValue Load = DAG.getLoad(RegVT, dl, Chain, Ptr,
    475                                  LD->getPointerInfo().getWithOffset(Offset),
    476                                  LD->isVolatile(), LD->isNonTemporal(),
    477                                  LD->isInvariant(),
    478                                  MinAlign(LD->getAlignment(), Offset),
    479                                  LD->getTBAAInfo());
    480       // Follow the load with a store to the stack slot.  Remember the store.
    481       Stores.push_back(DAG.getStore(Load.getValue(1), dl, Load, StackPtr,
    482                                     MachinePointerInfo(), false, false, 0));
    483       // Increment the pointers.
    484       Offset += RegBytes;
    485       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, Increment);
    486       StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
    487                              Increment);
    488     }
    489 
    490     // The last copy may be partial.  Do an extending load.
    491     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(),
    492                                   8 * (LoadedBytes - Offset));
    493     SDValue Load = DAG.getExtLoad(ISD::EXTLOAD, dl, RegVT, Chain, Ptr,
    494                                   LD->getPointerInfo().getWithOffset(Offset),
    495                                   MemVT, LD->isVolatile(),
    496                                   LD->isNonTemporal(),
    497                                   MinAlign(LD->getAlignment(), Offset),
    498                                   LD->getTBAAInfo());
    499     // Follow the load with a store to the stack slot.  Remember the store.
    500     // On big-endian machines this requires a truncating store to ensure
    501     // that the bits end up in the right place.
    502     Stores.push_back(DAG.getTruncStore(Load.getValue(1), dl, Load, StackPtr,
    503                                        MachinePointerInfo(), MemVT,
    504                                        false, false, 0));
    505 
    506     // The order of the stores doesn't matter - say it with a TokenFactor.
    507     SDValue TF = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
    508 
    509     // Finally, perform the original load only redirected to the stack slot.
    510     Load = DAG.getExtLoad(LD->getExtensionType(), dl, VT, TF, StackBase,
    511                           MachinePointerInfo(), LoadedVT, false, false, 0);
    512 
    513     // Callers expect a MERGE_VALUES node.
    514     ValResult = Load;
    515     ChainResult = TF;
    516     return;
    517   }
    518   assert(LoadedVT.isInteger() && !LoadedVT.isVector() &&
    519          "Unaligned load of unsupported type.");
    520 
    521   // Compute the new VT that is half the size of the old one.  This is an
    522   // integer MVT.
    523   unsigned NumBits = LoadedVT.getSizeInBits();
    524   EVT NewLoadedVT;
    525   NewLoadedVT = EVT::getIntegerVT(*DAG.getContext(), NumBits/2);
    526   NumBits >>= 1;
    527 
    528   unsigned Alignment = LD->getAlignment();
    529   unsigned IncrementSize = NumBits / 8;
    530   ISD::LoadExtType HiExtType = LD->getExtensionType();
    531 
    532   // If the original load is NON_EXTLOAD, the hi part load must be ZEXTLOAD.
    533   if (HiExtType == ISD::NON_EXTLOAD)
    534     HiExtType = ISD::ZEXTLOAD;
    535 
    536   // Load the value in two parts
    537   SDValue Lo, Hi;
    538   if (TLI.isLittleEndian()) {
    539     Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, VT, Chain, Ptr, LD->getPointerInfo(),
    540                         NewLoadedVT, LD->isVolatile(),
    541                         LD->isNonTemporal(), Alignment, LD->getTBAAInfo());
    542     Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    543                       DAG.getConstant(IncrementSize, Ptr.getValueType()));
    544     Hi = DAG.getExtLoad(HiExtType, dl, VT, Chain, Ptr,
    545                         LD->getPointerInfo().getWithOffset(IncrementSize),
    546                         NewLoadedVT, LD->isVolatile(),
    547                         LD->isNonTemporal(), MinAlign(Alignment, IncrementSize),
    548                         LD->getTBAAInfo());
    549   } else {
    550     Hi = DAG.getExtLoad(HiExtType, dl, VT, Chain, Ptr, LD->getPointerInfo(),
    551                         NewLoadedVT, LD->isVolatile(),
    552                         LD->isNonTemporal(), Alignment, LD->getTBAAInfo());
    553     Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    554                       DAG.getConstant(IncrementSize, Ptr.getValueType()));
    555     Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, VT, Chain, Ptr,
    556                         LD->getPointerInfo().getWithOffset(IncrementSize),
    557                         NewLoadedVT, LD->isVolatile(),
    558                         LD->isNonTemporal(), MinAlign(Alignment, IncrementSize),
    559                         LD->getTBAAInfo());
    560   }
    561 
    562   // aggregate the two parts
    563   SDValue ShiftAmount = DAG.getConstant(NumBits,
    564                                        TLI.getShiftAmountTy(Hi.getValueType()));
    565   SDValue Result = DAG.getNode(ISD::SHL, dl, VT, Hi, ShiftAmount);
    566   Result = DAG.getNode(ISD::OR, dl, VT, Result, Lo);
    567 
    568   SDValue TF = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
    569                              Hi.getValue(1));
    570 
    571   ValResult = Result;
    572   ChainResult = TF;
    573 }
    574 
    575 /// PerformInsertVectorEltInMemory - Some target cannot handle a variable
    576 /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
    577 /// is necessary to spill the vector being inserted into to memory, perform
    578 /// the insert there, and then read the result back.
    579 SDValue SelectionDAGLegalize::
    580 PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
    581                                SDLoc dl) {
    582   SDValue Tmp1 = Vec;
    583   SDValue Tmp2 = Val;
    584   SDValue Tmp3 = Idx;
    585 
    586   // If the target doesn't support this, we have to spill the input vector
    587   // to a temporary stack slot, update the element, then reload it.  This is
    588   // badness.  We could also load the value into a vector register (either
    589   // with a "move to register" or "extload into register" instruction, then
    590   // permute it into place, if the idx is a constant and if the idx is
    591   // supported by the target.
    592   EVT VT    = Tmp1.getValueType();
    593   EVT EltVT = VT.getVectorElementType();
    594   EVT IdxVT = Tmp3.getValueType();
    595   EVT PtrVT = TLI.getPointerTy();
    596   SDValue StackPtr = DAG.CreateStackTemporary(VT);
    597 
    598   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
    599 
    600   // Store the vector.
    601   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Tmp1, StackPtr,
    602                             MachinePointerInfo::getFixedStack(SPFI),
    603                             false, false, 0);
    604 
    605   // Truncate or zero extend offset to target pointer type.
    606   unsigned CastOpc = IdxVT.bitsGT(PtrVT) ? ISD::TRUNCATE : ISD::ZERO_EXTEND;
    607   Tmp3 = DAG.getNode(CastOpc, dl, PtrVT, Tmp3);
    608   // Add the offset to the index.
    609   unsigned EltSize = EltVT.getSizeInBits()/8;
    610   Tmp3 = DAG.getNode(ISD::MUL, dl, IdxVT, Tmp3,DAG.getConstant(EltSize, IdxVT));
    611   SDValue StackPtr2 = DAG.getNode(ISD::ADD, dl, IdxVT, Tmp3, StackPtr);
    612   // Store the scalar value.
    613   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT,
    614                          false, false, 0);
    615   // Load the updated vector.
    616   return DAG.getLoad(VT, dl, Ch, StackPtr,
    617                      MachinePointerInfo::getFixedStack(SPFI), false, false,
    618                      false, 0);
    619 }
    620 
    621 
    622 SDValue SelectionDAGLegalize::
    623 ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx, SDLoc dl) {
    624   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
    625     // SCALAR_TO_VECTOR requires that the type of the value being inserted
    626     // match the element type of the vector being created, except for
    627     // integers in which case the inserted value can be over width.
    628     EVT EltVT = Vec.getValueType().getVectorElementType();
    629     if (Val.getValueType() == EltVT ||
    630         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
    631       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
    632                                   Vec.getValueType(), Val);
    633 
    634       unsigned NumElts = Vec.getValueType().getVectorNumElements();
    635       // We generate a shuffle of InVec and ScVec, so the shuffle mask
    636       // should be 0,1,2,3,4,5... with the appropriate element replaced with
    637       // elt 0 of the RHS.
    638       SmallVector<int, 8> ShufOps;
    639       for (unsigned i = 0; i != NumElts; ++i)
    640         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
    641 
    642       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec,
    643                                   &ShufOps[0]);
    644     }
    645   }
    646   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
    647 }
    648 
    649 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
    650   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
    651   // FIXME: We shouldn't do this for TargetConstantFP's.
    652   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
    653   // to phase ordering between legalized code and the dag combiner.  This
    654   // probably means that we need to integrate dag combiner and legalizer
    655   // together.
    656   // We generally can't do this one for long doubles.
    657   SDValue Chain = ST->getChain();
    658   SDValue Ptr = ST->getBasePtr();
    659   unsigned Alignment = ST->getAlignment();
    660   bool isVolatile = ST->isVolatile();
    661   bool isNonTemporal = ST->isNonTemporal();
    662   const MDNode *TBAAInfo = ST->getTBAAInfo();
    663   SDLoc dl(ST);
    664   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
    665     if (CFP->getValueType(0) == MVT::f32 &&
    666         TLI.isTypeLegal(MVT::i32)) {
    667       SDValue Con = DAG.getConstant(CFP->getValueAPF().
    668                                       bitcastToAPInt().zextOrTrunc(32),
    669                               MVT::i32);
    670       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
    671                           isVolatile, isNonTemporal, Alignment, TBAAInfo);
    672     }
    673 
    674     if (CFP->getValueType(0) == MVT::f64) {
    675       // If this target supports 64-bit registers, do a single 64-bit store.
    676       if (TLI.isTypeLegal(MVT::i64)) {
    677         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
    678                                   zextOrTrunc(64), MVT::i64);
    679         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
    680                             isVolatile, isNonTemporal, Alignment, TBAAInfo);
    681       }
    682 
    683       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
    684         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
    685         // stores.  If the target supports neither 32- nor 64-bits, this
    686         // xform is certainly not worth it.
    687         const APInt &IntVal =CFP->getValueAPF().bitcastToAPInt();
    688         SDValue Lo = DAG.getConstant(IntVal.trunc(32), MVT::i32);
    689         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), MVT::i32);
    690         if (TLI.isBigEndian()) std::swap(Lo, Hi);
    691 
    692         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), isVolatile,
    693                           isNonTemporal, Alignment, TBAAInfo);
    694         Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    695                           DAG.getConstant(4, Ptr.getValueType()));
    696         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
    697                           ST->getPointerInfo().getWithOffset(4),
    698                           isVolatile, isNonTemporal, MinAlign(Alignment, 4U),
    699                           TBAAInfo);
    700 
    701         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
    702       }
    703     }
    704   }
    705   return SDValue(nullptr, 0);
    706 }
    707 
    708 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
    709     StoreSDNode *ST = cast<StoreSDNode>(Node);
    710     SDValue Chain = ST->getChain();
    711     SDValue Ptr = ST->getBasePtr();
    712     SDLoc dl(Node);
    713 
    714     unsigned Alignment = ST->getAlignment();
    715     bool isVolatile = ST->isVolatile();
    716     bool isNonTemporal = ST->isNonTemporal();
    717     const MDNode *TBAAInfo = ST->getTBAAInfo();
    718 
    719     if (!ST->isTruncatingStore()) {
    720       if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
    721         ReplaceNode(ST, OptStore);
    722         return;
    723       }
    724 
    725       {
    726         SDValue Value = ST->getValue();
    727         MVT VT = Value.getSimpleValueType();
    728         switch (TLI.getOperationAction(ISD::STORE, VT)) {
    729         default: llvm_unreachable("This action is not supported yet!");
    730         case TargetLowering::Legal: {
    731           // If this is an unaligned store and the target doesn't support it,
    732           // expand it.
    733           unsigned AS = ST->getAddressSpace();
    734           if (!TLI.allowsUnalignedMemoryAccesses(ST->getMemoryVT(), AS)) {
    735             Type *Ty = ST->getMemoryVT().getTypeForEVT(*DAG.getContext());
    736             unsigned ABIAlignment= TLI.getDataLayout()->getABITypeAlignment(Ty);
    737             if (ST->getAlignment() < ABIAlignment)
    738               ExpandUnalignedStore(cast<StoreSDNode>(Node),
    739                                    DAG, TLI, this);
    740           }
    741           break;
    742         }
    743         case TargetLowering::Custom: {
    744           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
    745           if (Res.getNode())
    746             ReplaceNode(SDValue(Node, 0), Res);
    747           return;
    748         }
    749         case TargetLowering::Promote: {
    750           MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
    751           assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
    752                  "Can only promote stores to same size type");
    753           Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
    754           SDValue Result =
    755             DAG.getStore(Chain, dl, Value, Ptr,
    756                          ST->getPointerInfo(), isVolatile,
    757                          isNonTemporal, Alignment, TBAAInfo);
    758           ReplaceNode(SDValue(Node, 0), Result);
    759           break;
    760         }
    761         }
    762         return;
    763       }
    764     } else {
    765       SDValue Value = ST->getValue();
    766 
    767       EVT StVT = ST->getMemoryVT();
    768       unsigned StWidth = StVT.getSizeInBits();
    769 
    770       if (StWidth != StVT.getStoreSizeInBits()) {
    771         // Promote to a byte-sized store with upper bits zero if not
    772         // storing an integral number of bytes.  For example, promote
    773         // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
    774         EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
    775                                     StVT.getStoreSizeInBits());
    776         Value = DAG.getZeroExtendInReg(Value, dl, StVT);
    777         SDValue Result =
    778           DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
    779                             NVT, isVolatile, isNonTemporal, Alignment,
    780                             TBAAInfo);
    781         ReplaceNode(SDValue(Node, 0), Result);
    782       } else if (StWidth & (StWidth - 1)) {
    783         // If not storing a power-of-2 number of bits, expand as two stores.
    784         assert(!StVT.isVector() && "Unsupported truncstore!");
    785         unsigned RoundWidth = 1 << Log2_32(StWidth);
    786         assert(RoundWidth < StWidth);
    787         unsigned ExtraWidth = StWidth - RoundWidth;
    788         assert(ExtraWidth < RoundWidth);
    789         assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
    790                "Store size not an integral number of bytes!");
    791         EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
    792         EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
    793         SDValue Lo, Hi;
    794         unsigned IncrementSize;
    795 
    796         if (TLI.isLittleEndian()) {
    797           // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
    798           // Store the bottom RoundWidth bits.
    799           Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
    800                                  RoundVT,
    801                                  isVolatile, isNonTemporal, Alignment,
    802                                  TBAAInfo);
    803 
    804           // Store the remaining ExtraWidth bits.
    805           IncrementSize = RoundWidth / 8;
    806           Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    807                             DAG.getConstant(IncrementSize, Ptr.getValueType()));
    808           Hi = DAG.getNode(ISD::SRL, dl, Value.getValueType(), Value,
    809                            DAG.getConstant(RoundWidth,
    810                                    TLI.getShiftAmountTy(Value.getValueType())));
    811           Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr,
    812                              ST->getPointerInfo().getWithOffset(IncrementSize),
    813                                  ExtraVT, isVolatile, isNonTemporal,
    814                                  MinAlign(Alignment, IncrementSize), TBAAInfo);
    815         } else {
    816           // Big endian - avoid unaligned stores.
    817           // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
    818           // Store the top RoundWidth bits.
    819           Hi = DAG.getNode(ISD::SRL, dl, Value.getValueType(), Value,
    820                            DAG.getConstant(ExtraWidth,
    821                                    TLI.getShiftAmountTy(Value.getValueType())));
    822           Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
    823                                  RoundVT, isVolatile, isNonTemporal, Alignment,
    824                                  TBAAInfo);
    825 
    826           // Store the remaining ExtraWidth bits.
    827           IncrementSize = RoundWidth / 8;
    828           Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    829                             DAG.getConstant(IncrementSize, Ptr.getValueType()));
    830           Lo = DAG.getTruncStore(Chain, dl, Value, Ptr,
    831                               ST->getPointerInfo().getWithOffset(IncrementSize),
    832                                  ExtraVT, isVolatile, isNonTemporal,
    833                                  MinAlign(Alignment, IncrementSize), TBAAInfo);
    834         }
    835 
    836         // The order of the stores doesn't matter.
    837         SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
    838         ReplaceNode(SDValue(Node, 0), Result);
    839       } else {
    840         switch (TLI.getTruncStoreAction(ST->getValue().getSimpleValueType(),
    841                                         StVT.getSimpleVT())) {
    842         default: llvm_unreachable("This action is not supported yet!");
    843         case TargetLowering::Legal: {
    844           unsigned AS = ST->getAddressSpace();
    845           // If this is an unaligned store and the target doesn't support it,
    846           // expand it.
    847           if (!TLI.allowsUnalignedMemoryAccesses(ST->getMemoryVT(), AS)) {
    848             Type *Ty = ST->getMemoryVT().getTypeForEVT(*DAG.getContext());
    849             unsigned ABIAlignment= TLI.getDataLayout()->getABITypeAlignment(Ty);
    850             if (ST->getAlignment() < ABIAlignment)
    851               ExpandUnalignedStore(cast<StoreSDNode>(Node), DAG, TLI, this);
    852           }
    853           break;
    854         }
    855         case TargetLowering::Custom: {
    856           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
    857           if (Res.getNode())
    858             ReplaceNode(SDValue(Node, 0), Res);
    859           return;
    860         }
    861         case TargetLowering::Expand:
    862           assert(!StVT.isVector() &&
    863                  "Vector Stores are handled in LegalizeVectorOps");
    864 
    865           // TRUNCSTORE:i16 i32 -> STORE i16
    866           assert(TLI.isTypeLegal(StVT) &&
    867                  "Do not know how to expand this store!");
    868           Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
    869           SDValue Result =
    870             DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
    871                          isVolatile, isNonTemporal, Alignment, TBAAInfo);
    872           ReplaceNode(SDValue(Node, 0), Result);
    873           break;
    874         }
    875       }
    876     }
    877 }
    878 
    879 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
    880   LoadSDNode *LD = cast<LoadSDNode>(Node);
    881   SDValue Chain = LD->getChain();  // The chain.
    882   SDValue Ptr = LD->getBasePtr();  // The base pointer.
    883   SDValue Value;                   // The value returned by the load op.
    884   SDLoc dl(Node);
    885 
    886   ISD::LoadExtType ExtType = LD->getExtensionType();
    887   if (ExtType == ISD::NON_EXTLOAD) {
    888     MVT VT = Node->getSimpleValueType(0);
    889     SDValue RVal = SDValue(Node, 0);
    890     SDValue RChain = SDValue(Node, 1);
    891 
    892     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
    893     default: llvm_unreachable("This action is not supported yet!");
    894     case TargetLowering::Legal: {
    895       unsigned AS = LD->getAddressSpace();
    896       // If this is an unaligned load and the target doesn't support it,
    897       // expand it.
    898       if (!TLI.allowsUnalignedMemoryAccesses(LD->getMemoryVT(), AS)) {
    899         Type *Ty = LD->getMemoryVT().getTypeForEVT(*DAG.getContext());
    900         unsigned ABIAlignment =
    901           TLI.getDataLayout()->getABITypeAlignment(Ty);
    902         if (LD->getAlignment() < ABIAlignment){
    903           ExpandUnalignedLoad(cast<LoadSDNode>(Node), DAG, TLI, RVal, RChain);
    904         }
    905       }
    906       break;
    907     }
    908     case TargetLowering::Custom: {
    909       SDValue Res = TLI.LowerOperation(RVal, DAG);
    910       if (Res.getNode()) {
    911         RVal = Res;
    912         RChain = Res.getValue(1);
    913       }
    914       break;
    915     }
    916     case TargetLowering::Promote: {
    917       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
    918       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
    919              "Can only promote loads to same size type");
    920 
    921       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
    922       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
    923       RChain = Res.getValue(1);
    924       break;
    925     }
    926     }
    927     if (RChain.getNode() != Node) {
    928       assert(RVal.getNode() != Node && "Load must be completely replaced");
    929       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
    930       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
    931       ReplacedNode(Node);
    932     }
    933     return;
    934   }
    935 
    936   EVT SrcVT = LD->getMemoryVT();
    937   unsigned SrcWidth = SrcVT.getSizeInBits();
    938   unsigned Alignment = LD->getAlignment();
    939   bool isVolatile = LD->isVolatile();
    940   bool isNonTemporal = LD->isNonTemporal();
    941   const MDNode *TBAAInfo = LD->getTBAAInfo();
    942 
    943   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
    944       // Some targets pretend to have an i1 loading operation, and actually
    945       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
    946       // bits are guaranteed to be zero; it helps the optimizers understand
    947       // that these bits are zero.  It is also useful for EXTLOAD, since it
    948       // tells the optimizers that those bits are undefined.  It would be
    949       // nice to have an effective generic way of getting these benefits...
    950       // Until such a way is found, don't insist on promoting i1 here.
    951       (SrcVT != MVT::i1 ||
    952        TLI.getLoadExtAction(ExtType, MVT::i1) == TargetLowering::Promote)) {
    953     // Promote to a byte-sized load if not loading an integral number of
    954     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
    955     unsigned NewWidth = SrcVT.getStoreSizeInBits();
    956     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
    957     SDValue Ch;
    958 
    959     // The extra bits are guaranteed to be zero, since we stored them that
    960     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
    961 
    962     ISD::LoadExtType NewExtType =
    963       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
    964 
    965     SDValue Result =
    966       DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
    967                      Chain, Ptr, LD->getPointerInfo(),
    968                      NVT, isVolatile, isNonTemporal, Alignment, TBAAInfo);
    969 
    970     Ch = Result.getValue(1); // The chain.
    971 
    972     if (ExtType == ISD::SEXTLOAD)
    973       // Having the top bits zero doesn't help when sign extending.
    974       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
    975                            Result.getValueType(),
    976                            Result, DAG.getValueType(SrcVT));
    977     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
    978       // All the top bits are guaranteed to be zero - inform the optimizers.
    979       Result = DAG.getNode(ISD::AssertZext, dl,
    980                            Result.getValueType(), Result,
    981                            DAG.getValueType(SrcVT));
    982 
    983     Value = Result;
    984     Chain = Ch;
    985   } else if (SrcWidth & (SrcWidth - 1)) {
    986     // If not loading a power-of-2 number of bits, expand as two loads.
    987     assert(!SrcVT.isVector() && "Unsupported extload!");
    988     unsigned RoundWidth = 1 << Log2_32(SrcWidth);
    989     assert(RoundWidth < SrcWidth);
    990     unsigned ExtraWidth = SrcWidth - RoundWidth;
    991     assert(ExtraWidth < RoundWidth);
    992     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
    993            "Load size not an integral number of bytes!");
    994     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
    995     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
    996     SDValue Lo, Hi, Ch;
    997     unsigned IncrementSize;
    998 
    999     if (TLI.isLittleEndian()) {
   1000       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
   1001       // Load the bottom RoundWidth bits.
   1002       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0),
   1003                           Chain, Ptr,
   1004                           LD->getPointerInfo(), RoundVT, isVolatile,
   1005                           isNonTemporal, Alignment, TBAAInfo);
   1006 
   1007       // Load the remaining ExtraWidth bits.
   1008       IncrementSize = RoundWidth / 8;
   1009       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
   1010                          DAG.getConstant(IncrementSize, Ptr.getValueType()));
   1011       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
   1012                           LD->getPointerInfo().getWithOffset(IncrementSize),
   1013                           ExtraVT, isVolatile, isNonTemporal,
   1014                           MinAlign(Alignment, IncrementSize), TBAAInfo);
   1015 
   1016       // Build a factor node to remember that this load is independent of
   1017       // the other one.
   1018       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
   1019                        Hi.getValue(1));
   1020 
   1021       // Move the top bits to the right place.
   1022       Hi = DAG.getNode(ISD::SHL, dl, Hi.getValueType(), Hi,
   1023                        DAG.getConstant(RoundWidth,
   1024                                       TLI.getShiftAmountTy(Hi.getValueType())));
   1025 
   1026       // Join the hi and lo parts.
   1027       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
   1028     } else {
   1029       // Big endian - avoid unaligned loads.
   1030       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
   1031       // Load the top RoundWidth bits.
   1032       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
   1033                           LD->getPointerInfo(), RoundVT, isVolatile,
   1034                           isNonTemporal, Alignment, TBAAInfo);
   1035 
   1036       // Load the remaining ExtraWidth bits.
   1037       IncrementSize = RoundWidth / 8;
   1038       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
   1039                          DAG.getConstant(IncrementSize, Ptr.getValueType()));
   1040       Lo = DAG.getExtLoad(ISD::ZEXTLOAD,
   1041                           dl, Node->getValueType(0), Chain, Ptr,
   1042                           LD->getPointerInfo().getWithOffset(IncrementSize),
   1043                           ExtraVT, isVolatile, isNonTemporal,
   1044                           MinAlign(Alignment, IncrementSize), TBAAInfo);
   1045 
   1046       // Build a factor node to remember that this load is independent of
   1047       // the other one.
   1048       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
   1049                        Hi.getValue(1));
   1050 
   1051       // Move the top bits to the right place.
   1052       Hi = DAG.getNode(ISD::SHL, dl, Hi.getValueType(), Hi,
   1053                        DAG.getConstant(ExtraWidth,
   1054                                       TLI.getShiftAmountTy(Hi.getValueType())));
   1055 
   1056       // Join the hi and lo parts.
   1057       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
   1058     }
   1059 
   1060     Chain = Ch;
   1061   } else {
   1062     bool isCustom = false;
   1063     switch (TLI.getLoadExtAction(ExtType, SrcVT.getSimpleVT())) {
   1064     default: llvm_unreachable("This action is not supported yet!");
   1065     case TargetLowering::Custom:
   1066       isCustom = true;
   1067       // FALLTHROUGH
   1068     case TargetLowering::Legal: {
   1069       Value = SDValue(Node, 0);
   1070       Chain = SDValue(Node, 1);
   1071 
   1072       if (isCustom) {
   1073         SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
   1074         if (Res.getNode()) {
   1075           Value = Res;
   1076           Chain = Res.getValue(1);
   1077         }
   1078       } else {
   1079         // If this is an unaligned load and the target doesn't support
   1080         // it, expand it.
   1081         EVT MemVT = LD->getMemoryVT();
   1082         unsigned AS = LD->getAddressSpace();
   1083         if (!TLI.allowsUnalignedMemoryAccesses(MemVT, AS)) {
   1084           Type *Ty =
   1085             LD->getMemoryVT().getTypeForEVT(*DAG.getContext());
   1086           unsigned ABIAlignment =
   1087             TLI.getDataLayout()->getABITypeAlignment(Ty);
   1088           if (LD->getAlignment() < ABIAlignment){
   1089             ExpandUnalignedLoad(cast<LoadSDNode>(Node),
   1090                                 DAG, TLI, Value, Chain);
   1091           }
   1092         }
   1093       }
   1094       break;
   1095     }
   1096     case TargetLowering::Expand:
   1097       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, SrcVT) &&
   1098           TLI.isTypeLegal(SrcVT)) {
   1099         SDValue Load = DAG.getLoad(SrcVT, dl, Chain, Ptr,
   1100                                    LD->getMemOperand());
   1101         unsigned ExtendOp;
   1102         switch (ExtType) {
   1103         case ISD::EXTLOAD:
   1104           ExtendOp = (SrcVT.isFloatingPoint() ?
   1105                       ISD::FP_EXTEND : ISD::ANY_EXTEND);
   1106           break;
   1107         case ISD::SEXTLOAD: ExtendOp = ISD::SIGN_EXTEND; break;
   1108         case ISD::ZEXTLOAD: ExtendOp = ISD::ZERO_EXTEND; break;
   1109         default: llvm_unreachable("Unexpected extend load type!");
   1110         }
   1111         Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
   1112         Chain = Load.getValue(1);
   1113         break;
   1114       }
   1115 
   1116       assert(!SrcVT.isVector() &&
   1117              "Vector Loads are handled in LegalizeVectorOps");
   1118 
   1119       // FIXME: This does not work for vectors on most targets.  Sign-
   1120       // and zero-extend operations are currently folded into extending
   1121       // loads, whether they are legal or not, and then we end up here
   1122       // without any support for legalizing them.
   1123       assert(ExtType != ISD::EXTLOAD &&
   1124              "EXTLOAD should always be supported!");
   1125       // Turn the unsupported load into an EXTLOAD followed by an
   1126       // explicit zero/sign extend inreg.
   1127       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
   1128                                       Node->getValueType(0),
   1129                                       Chain, Ptr, SrcVT,
   1130                                       LD->getMemOperand());
   1131       SDValue ValRes;
   1132       if (ExtType == ISD::SEXTLOAD)
   1133         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
   1134                              Result.getValueType(),
   1135                              Result, DAG.getValueType(SrcVT));
   1136       else
   1137         ValRes = DAG.getZeroExtendInReg(Result, dl,
   1138                                         SrcVT.getScalarType());
   1139       Value = ValRes;
   1140       Chain = Result.getValue(1);
   1141       break;
   1142     }
   1143   }
   1144 
   1145   // Since loads produce two values, make sure to remember that we legalized
   1146   // both of them.
   1147   if (Chain.getNode() != Node) {
   1148     assert(Value.getNode() != Node && "Load must be completely replaced");
   1149     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
   1150     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
   1151     ReplacedNode(Node);
   1152   }
   1153 }
   1154 
   1155 /// LegalizeOp - Return a legal replacement for the given operation, with
   1156 /// all legal operands.
   1157 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
   1158   if (Node->getOpcode() == ISD::TargetConstant) // Allow illegal target nodes.
   1159     return;
   1160 
   1161   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
   1162     assert(TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
   1163              TargetLowering::TypeLegal &&
   1164            "Unexpected illegal type!");
   1165 
   1166   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i)
   1167     assert((TLI.getTypeAction(*DAG.getContext(),
   1168                               Node->getOperand(i).getValueType()) ==
   1169               TargetLowering::TypeLegal ||
   1170             Node->getOperand(i).getOpcode() == ISD::TargetConstant) &&
   1171            "Unexpected illegal type!");
   1172 
   1173   // Figure out the correct action; the way to query this varies by opcode
   1174   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
   1175   bool SimpleFinishLegalizing = true;
   1176   switch (Node->getOpcode()) {
   1177   case ISD::INTRINSIC_W_CHAIN:
   1178   case ISD::INTRINSIC_WO_CHAIN:
   1179   case ISD::INTRINSIC_VOID:
   1180   case ISD::STACKSAVE:
   1181     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
   1182     break;
   1183   case ISD::VAARG:
   1184     Action = TLI.getOperationAction(Node->getOpcode(),
   1185                                     Node->getValueType(0));
   1186     if (Action != TargetLowering::Promote)
   1187       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
   1188     break;
   1189   case ISD::SINT_TO_FP:
   1190   case ISD::UINT_TO_FP:
   1191   case ISD::EXTRACT_VECTOR_ELT:
   1192     Action = TLI.getOperationAction(Node->getOpcode(),
   1193                                     Node->getOperand(0).getValueType());
   1194     break;
   1195   case ISD::FP_ROUND_INREG:
   1196   case ISD::SIGN_EXTEND_INREG: {
   1197     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
   1198     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
   1199     break;
   1200   }
   1201   case ISD::ATOMIC_STORE: {
   1202     Action = TLI.getOperationAction(Node->getOpcode(),
   1203                                     Node->getOperand(2).getValueType());
   1204     break;
   1205   }
   1206   case ISD::SELECT_CC:
   1207   case ISD::SETCC:
   1208   case ISD::BR_CC: {
   1209     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
   1210                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
   1211     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 : 0;
   1212     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
   1213     ISD::CondCode CCCode =
   1214         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
   1215     Action = TLI.getCondCodeAction(CCCode, OpVT);
   1216     if (Action == TargetLowering::Legal) {
   1217       if (Node->getOpcode() == ISD::SELECT_CC)
   1218         Action = TLI.getOperationAction(Node->getOpcode(),
   1219                                         Node->getValueType(0));
   1220       else
   1221         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
   1222     }
   1223     break;
   1224   }
   1225   case ISD::LOAD:
   1226   case ISD::STORE:
   1227     // FIXME: Model these properly.  LOAD and STORE are complicated, and
   1228     // STORE expects the unlegalized operand in some cases.
   1229     SimpleFinishLegalizing = false;
   1230     break;
   1231   case ISD::CALLSEQ_START:
   1232   case ISD::CALLSEQ_END:
   1233     // FIXME: This shouldn't be necessary.  These nodes have special properties
   1234     // dealing with the recursive nature of legalization.  Removing this
   1235     // special case should be done as part of making LegalizeDAG non-recursive.
   1236     SimpleFinishLegalizing = false;
   1237     break;
   1238   case ISD::EXTRACT_ELEMENT:
   1239   case ISD::FLT_ROUNDS_:
   1240   case ISD::SADDO:
   1241   case ISD::SSUBO:
   1242   case ISD::UADDO:
   1243   case ISD::USUBO:
   1244   case ISD::SMULO:
   1245   case ISD::UMULO:
   1246   case ISD::FPOWI:
   1247   case ISD::MERGE_VALUES:
   1248   case ISD::EH_RETURN:
   1249   case ISD::FRAME_TO_ARGS_OFFSET:
   1250   case ISD::EH_SJLJ_SETJMP:
   1251   case ISD::EH_SJLJ_LONGJMP:
   1252     // These operations lie about being legal: when they claim to be legal,
   1253     // they should actually be expanded.
   1254     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
   1255     if (Action == TargetLowering::Legal)
   1256       Action = TargetLowering::Expand;
   1257     break;
   1258   case ISD::INIT_TRAMPOLINE:
   1259   case ISD::ADJUST_TRAMPOLINE:
   1260   case ISD::FRAMEADDR:
   1261   case ISD::RETURNADDR:
   1262     // These operations lie about being legal: when they claim to be legal,
   1263     // they should actually be custom-lowered.
   1264     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
   1265     if (Action == TargetLowering::Legal)
   1266       Action = TargetLowering::Custom;
   1267     break;
   1268   case ISD::READ_REGISTER:
   1269   case ISD::WRITE_REGISTER:
   1270     // Named register is legal in the DAG, but blocked by register name
   1271     // selection if not implemented by target (to chose the correct register)
   1272     // They'll be converted to Copy(To/From)Reg.
   1273     Action = TargetLowering::Legal;
   1274     break;
   1275   case ISD::DEBUGTRAP:
   1276     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
   1277     if (Action == TargetLowering::Expand) {
   1278       // replace ISD::DEBUGTRAP with ISD::TRAP
   1279       SDValue NewVal;
   1280       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
   1281                            Node->getOperand(0));
   1282       ReplaceNode(Node, NewVal.getNode());
   1283       LegalizeOp(NewVal.getNode());
   1284       return;
   1285     }
   1286     break;
   1287 
   1288   default:
   1289     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
   1290       Action = TargetLowering::Legal;
   1291     } else {
   1292       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
   1293     }
   1294     break;
   1295   }
   1296 
   1297   if (SimpleFinishLegalizing) {
   1298     SDNode *NewNode = Node;
   1299     switch (Node->getOpcode()) {
   1300     default: break;
   1301     case ISD::SHL:
   1302     case ISD::SRL:
   1303     case ISD::SRA:
   1304     case ISD::ROTL:
   1305     case ISD::ROTR:
   1306       // Legalizing shifts/rotates requires adjusting the shift amount
   1307       // to the appropriate width.
   1308       if (!Node->getOperand(1).getValueType().isVector()) {
   1309         SDValue SAO =
   1310           DAG.getShiftAmountOperand(Node->getOperand(0).getValueType(),
   1311                                     Node->getOperand(1));
   1312         HandleSDNode Handle(SAO);
   1313         LegalizeOp(SAO.getNode());
   1314         NewNode = DAG.UpdateNodeOperands(Node, Node->getOperand(0),
   1315                                          Handle.getValue());
   1316       }
   1317       break;
   1318     case ISD::SRL_PARTS:
   1319     case ISD::SRA_PARTS:
   1320     case ISD::SHL_PARTS:
   1321       // Legalizing shifts/rotates requires adjusting the shift amount
   1322       // to the appropriate width.
   1323       if (!Node->getOperand(2).getValueType().isVector()) {
   1324         SDValue SAO =
   1325           DAG.getShiftAmountOperand(Node->getOperand(0).getValueType(),
   1326                                     Node->getOperand(2));
   1327         HandleSDNode Handle(SAO);
   1328         LegalizeOp(SAO.getNode());
   1329         NewNode = DAG.UpdateNodeOperands(Node, Node->getOperand(0),
   1330                                          Node->getOperand(1),
   1331                                          Handle.getValue());
   1332       }
   1333       break;
   1334     }
   1335 
   1336     if (NewNode != Node) {
   1337       DAG.ReplaceAllUsesWith(Node, NewNode);
   1338       for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
   1339         DAG.TransferDbgValues(SDValue(Node, i), SDValue(NewNode, i));
   1340       ReplacedNode(Node);
   1341       Node = NewNode;
   1342     }
   1343     switch (Action) {
   1344     case TargetLowering::Legal:
   1345       return;
   1346     case TargetLowering::Custom: {
   1347       // FIXME: The handling for custom lowering with multiple results is
   1348       // a complete mess.
   1349       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
   1350       if (Res.getNode()) {
   1351         SmallVector<SDValue, 8> ResultVals;
   1352         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) {
   1353           if (e == 1)
   1354             ResultVals.push_back(Res);
   1355           else
   1356             ResultVals.push_back(Res.getValue(i));
   1357         }
   1358         if (Res.getNode() != Node || Res.getResNo() != 0) {
   1359           DAG.ReplaceAllUsesWith(Node, ResultVals.data());
   1360           for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
   1361             DAG.TransferDbgValues(SDValue(Node, i), ResultVals[i]);
   1362           ReplacedNode(Node);
   1363         }
   1364         return;
   1365       }
   1366     }
   1367       // FALL THROUGH
   1368     case TargetLowering::Expand:
   1369       ExpandNode(Node);
   1370       return;
   1371     case TargetLowering::Promote:
   1372       PromoteNode(Node);
   1373       return;
   1374     }
   1375   }
   1376 
   1377   switch (Node->getOpcode()) {
   1378   default:
   1379 #ifndef NDEBUG
   1380     dbgs() << "NODE: ";
   1381     Node->dump( &DAG);
   1382     dbgs() << "\n";
   1383 #endif
   1384     llvm_unreachable("Do not know how to legalize this operator!");
   1385 
   1386   case ISD::CALLSEQ_START:
   1387   case ISD::CALLSEQ_END:
   1388     break;
   1389   case ISD::LOAD: {
   1390     return LegalizeLoadOps(Node);
   1391   }
   1392   case ISD::STORE: {
   1393     return LegalizeStoreOps(Node);
   1394   }
   1395   }
   1396 }
   1397 
   1398 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
   1399   SDValue Vec = Op.getOperand(0);
   1400   SDValue Idx = Op.getOperand(1);
   1401   SDLoc dl(Op);
   1402 
   1403   // Before we generate a new store to a temporary stack slot, see if there is
   1404   // already one that we can use. There often is because when we scalarize
   1405   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
   1406   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
   1407   // the vector. If all are expanded here, we don't want one store per vector
   1408   // element.
   1409   SDValue StackPtr, Ch;
   1410   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
   1411        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
   1412     SDNode *User = *UI;
   1413     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
   1414       if (ST->isIndexed() || ST->isTruncatingStore() ||
   1415           ST->getValue() != Vec)
   1416         continue;
   1417 
   1418       // Make sure that nothing else could have stored into the destination of
   1419       // this store.
   1420       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
   1421         continue;
   1422 
   1423       StackPtr = ST->getBasePtr();
   1424       Ch = SDValue(ST, 0);
   1425       break;
   1426     }
   1427   }
   1428 
   1429   if (!Ch.getNode()) {
   1430     // Store the value to a temporary stack slot, then LOAD the returned part.
   1431     StackPtr = DAG.CreateStackTemporary(Vec.getValueType());
   1432     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
   1433                       MachinePointerInfo(), false, false, 0);
   1434   }
   1435 
   1436   // Add the offset to the index.
   1437   unsigned EltSize =
   1438       Vec.getValueType().getVectorElementType().getSizeInBits()/8;
   1439   Idx = DAG.getNode(ISD::MUL, dl, Idx.getValueType(), Idx,
   1440                     DAG.getConstant(EltSize, Idx.getValueType()));
   1441 
   1442   Idx = DAG.getZExtOrTrunc(Idx, dl, TLI.getPointerTy());
   1443   StackPtr = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, StackPtr);
   1444 
   1445   if (Op.getValueType().isVector())
   1446     return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr,MachinePointerInfo(),
   1447                        false, false, false, 0);
   1448   return DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
   1449                         MachinePointerInfo(),
   1450                         Vec.getValueType().getVectorElementType(),
   1451                         false, false, 0);
   1452 }
   1453 
   1454 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
   1455   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
   1456 
   1457   SDValue Vec  = Op.getOperand(0);
   1458   SDValue Part = Op.getOperand(1);
   1459   SDValue Idx  = Op.getOperand(2);
   1460   SDLoc dl(Op);
   1461 
   1462   // Store the value to a temporary stack slot, then LOAD the returned part.
   1463 
   1464   SDValue StackPtr = DAG.CreateStackTemporary(Vec.getValueType());
   1465   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
   1466   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(FI);
   1467 
   1468   // First store the whole vector.
   1469   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo,
   1470                             false, false, 0);
   1471 
   1472   // Then store the inserted part.
   1473 
   1474   // Add the offset to the index.
   1475   unsigned EltSize =
   1476       Vec.getValueType().getVectorElementType().getSizeInBits()/8;
   1477 
   1478   Idx = DAG.getNode(ISD::MUL, dl, Idx.getValueType(), Idx,
   1479                     DAG.getConstant(EltSize, Idx.getValueType()));
   1480   Idx = DAG.getZExtOrTrunc(Idx, dl, TLI.getPointerTy());
   1481 
   1482   SDValue SubStackPtr = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
   1483                                     StackPtr);
   1484 
   1485   // Store the subvector.
   1486   Ch = DAG.getStore(DAG.getEntryNode(), dl, Part, SubStackPtr,
   1487                     MachinePointerInfo(), false, false, 0);
   1488 
   1489   // Finally, load the updated vector.
   1490   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo,
   1491                      false, false, false, 0);
   1492 }
   1493 
   1494 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
   1495   // We can't handle this case efficiently.  Allocate a sufficiently
   1496   // aligned object on the stack, store each element into it, then load
   1497   // the result as a vector.
   1498   // Create the stack frame object.
   1499   EVT VT = Node->getValueType(0);
   1500   EVT EltVT = VT.getVectorElementType();
   1501   SDLoc dl(Node);
   1502   SDValue FIPtr = DAG.CreateStackTemporary(VT);
   1503   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
   1504   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(FI);
   1505 
   1506   // Emit a store of each element to the stack slot.
   1507   SmallVector<SDValue, 8> Stores;
   1508   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
   1509   // Store (in the right endianness) the elements to memory.
   1510   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
   1511     // Ignore undef elements.
   1512     if (Node->getOperand(i).getOpcode() == ISD::UNDEF) continue;
   1513 
   1514     unsigned Offset = TypeByteSize*i;
   1515 
   1516     SDValue Idx = DAG.getConstant(Offset, FIPtr.getValueType());
   1517     Idx = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr, Idx);
   1518 
   1519     // If the destination vector element type is narrower than the source
   1520     // element type, only store the bits necessary.
   1521     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
   1522       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
   1523                                          Node->getOperand(i), Idx,
   1524                                          PtrInfo.getWithOffset(Offset),
   1525                                          EltVT, false, false, 0));
   1526     } else
   1527       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl,
   1528                                     Node->getOperand(i), Idx,
   1529                                     PtrInfo.getWithOffset(Offset),
   1530                                     false, false, 0));
   1531   }
   1532 
   1533   SDValue StoreChain;
   1534   if (!Stores.empty())    // Not all undef elements?
   1535     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
   1536   else
   1537     StoreChain = DAG.getEntryNode();
   1538 
   1539   // Result is a load from the stack slot.
   1540   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo,
   1541                      false, false, false, 0);
   1542 }
   1543 
   1544 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode* Node) {
   1545   SDLoc dl(Node);
   1546   SDValue Tmp1 = Node->getOperand(0);
   1547   SDValue Tmp2 = Node->getOperand(1);
   1548 
   1549   // Get the sign bit of the RHS.  First obtain a value that has the same
   1550   // sign as the sign bit, i.e. negative if and only if the sign bit is 1.
   1551   SDValue SignBit;
   1552   EVT FloatVT = Tmp2.getValueType();
   1553   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), FloatVT.getSizeInBits());
   1554   if (TLI.isTypeLegal(IVT)) {
   1555     // Convert to an integer with the same sign bit.
   1556     SignBit = DAG.getNode(ISD::BITCAST, dl, IVT, Tmp2);
   1557   } else {
   1558     // Store the float to memory, then load the sign part out as an integer.
   1559     MVT LoadTy = TLI.getPointerTy();
   1560     // First create a temporary that is aligned for both the load and store.
   1561     SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
   1562     // Then store the float to it.
   1563     SDValue Ch =
   1564       DAG.getStore(DAG.getEntryNode(), dl, Tmp2, StackPtr, MachinePointerInfo(),
   1565                    false, false, 0);
   1566     if (TLI.isBigEndian()) {
   1567       assert(FloatVT.isByteSized() && "Unsupported floating point type!");
   1568       // Load out a legal integer with the same sign bit as the float.
   1569       SignBit = DAG.getLoad(LoadTy, dl, Ch, StackPtr, MachinePointerInfo(),
   1570                             false, false, false, 0);
   1571     } else { // Little endian
   1572       SDValue LoadPtr = StackPtr;
   1573       // The float may be wider than the integer we are going to load.  Advance
   1574       // the pointer so that the loaded integer will contain the sign bit.
   1575       unsigned Strides = (FloatVT.getSizeInBits()-1)/LoadTy.getSizeInBits();
   1576       unsigned ByteOffset = (Strides * LoadTy.getSizeInBits()) / 8;
   1577       LoadPtr = DAG.getNode(ISD::ADD, dl, LoadPtr.getValueType(), LoadPtr,
   1578                            DAG.getConstant(ByteOffset, LoadPtr.getValueType()));
   1579       // Load a legal integer containing the sign bit.
   1580       SignBit = DAG.getLoad(LoadTy, dl, Ch, LoadPtr, MachinePointerInfo(),
   1581                             false, false, false, 0);
   1582       // Move the sign bit to the top bit of the loaded integer.
   1583       unsigned BitShift = LoadTy.getSizeInBits() -
   1584         (FloatVT.getSizeInBits() - 8 * ByteOffset);
   1585       assert(BitShift < LoadTy.getSizeInBits() && "Pointer advanced wrong?");
   1586       if (BitShift)
   1587         SignBit = DAG.getNode(ISD::SHL, dl, LoadTy, SignBit,
   1588                               DAG.getConstant(BitShift,
   1589                                  TLI.getShiftAmountTy(SignBit.getValueType())));
   1590     }
   1591   }
   1592   // Now get the sign bit proper, by seeing whether the value is negative.
   1593   SignBit = DAG.getSetCC(dl, getSetCCResultType(SignBit.getValueType()),
   1594                          SignBit, DAG.getConstant(0, SignBit.getValueType()),
   1595                          ISD::SETLT);
   1596   // Get the absolute value of the result.
   1597   SDValue AbsVal = DAG.getNode(ISD::FABS, dl, Tmp1.getValueType(), Tmp1);
   1598   // Select between the nabs and abs value based on the sign bit of
   1599   // the input.
   1600   return DAG.getSelect(dl, AbsVal.getValueType(), SignBit,
   1601                       DAG.getNode(ISD::FNEG, dl, AbsVal.getValueType(), AbsVal),
   1602                       AbsVal);
   1603 }
   1604 
   1605 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
   1606                                            SmallVectorImpl<SDValue> &Results) {
   1607   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
   1608   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
   1609           " not tell us which reg is the stack pointer!");
   1610   SDLoc dl(Node);
   1611   EVT VT = Node->getValueType(0);
   1612   SDValue Tmp1 = SDValue(Node, 0);
   1613   SDValue Tmp2 = SDValue(Node, 1);
   1614   SDValue Tmp3 = Node->getOperand(2);
   1615   SDValue Chain = Tmp1.getOperand(0);
   1616 
   1617   // Chain the dynamic stack allocation so that it doesn't modify the stack
   1618   // pointer when other instructions are using the stack.
   1619   Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(0, true),
   1620                                SDLoc(Node));
   1621 
   1622   SDValue Size  = Tmp2.getOperand(1);
   1623   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
   1624   Chain = SP.getValue(1);
   1625   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
   1626   unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
   1627   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
   1628   if (Align > StackAlign)
   1629     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
   1630                        DAG.getConstant(-(uint64_t)Align, VT));
   1631   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
   1632 
   1633   Tmp2 = DAG.getCALLSEQ_END(Chain,  DAG.getIntPtrConstant(0, true),
   1634                             DAG.getIntPtrConstant(0, true), SDValue(),
   1635                             SDLoc(Node));
   1636 
   1637   Results.push_back(Tmp1);
   1638   Results.push_back(Tmp2);
   1639 }
   1640 
   1641 /// LegalizeSetCCCondCode - Legalize a SETCC with given LHS and RHS and
   1642 /// condition code CC on the current target.
   1643 ///
   1644 /// If the SETCC has been legalized using AND / OR, then the legalized node
   1645 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
   1646 /// will be set to false.
   1647 ///
   1648 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
   1649 /// then the values of LHS and RHS will be swapped, CC will be set to the
   1650 /// new condition, and NeedInvert will be set to false.
   1651 ///
   1652 /// If the SETCC has been legalized using the inverse condcode, then LHS and
   1653 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
   1654 /// will be set to true. The caller must invert the result of the SETCC with
   1655 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
   1656 /// of a true/false result.
   1657 ///
   1658 /// \returns true if the SetCC has been legalized, false if it hasn't.
   1659 bool SelectionDAGLegalize::LegalizeSetCCCondCode(EVT VT,
   1660                                                  SDValue &LHS, SDValue &RHS,
   1661                                                  SDValue &CC,
   1662                                                  bool &NeedInvert,
   1663                                                  SDLoc dl) {
   1664   MVT OpVT = LHS.getSimpleValueType();
   1665   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
   1666   NeedInvert = false;
   1667   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
   1668   default: llvm_unreachable("Unknown condition code action!");
   1669   case TargetLowering::Legal:
   1670     // Nothing to do.
   1671     break;
   1672   case TargetLowering::Expand: {
   1673     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
   1674     if (TLI.isCondCodeLegal(InvCC, OpVT)) {
   1675       std::swap(LHS, RHS);
   1676       CC = DAG.getCondCode(InvCC);
   1677       return true;
   1678     }
   1679     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
   1680     unsigned Opc = 0;
   1681     switch (CCCode) {
   1682     default: llvm_unreachable("Don't know how to expand this condition!");
   1683     case ISD::SETO:
   1684         assert(TLI.getCondCodeAction(ISD::SETOEQ, OpVT)
   1685             == TargetLowering::Legal
   1686             && "If SETO is expanded, SETOEQ must be legal!");
   1687         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
   1688     case ISD::SETUO:
   1689         assert(TLI.getCondCodeAction(ISD::SETUNE, OpVT)
   1690             == TargetLowering::Legal
   1691             && "If SETUO is expanded, SETUNE must be legal!");
   1692         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
   1693     case ISD::SETOEQ:
   1694     case ISD::SETOGT:
   1695     case ISD::SETOGE:
   1696     case ISD::SETOLT:
   1697     case ISD::SETOLE:
   1698     case ISD::SETONE:
   1699     case ISD::SETUEQ:
   1700     case ISD::SETUNE:
   1701     case ISD::SETUGT:
   1702     case ISD::SETUGE:
   1703     case ISD::SETULT:
   1704     case ISD::SETULE:
   1705         // If we are floating point, assign and break, otherwise fall through.
   1706         if (!OpVT.isInteger()) {
   1707           // We can use the 4th bit to tell if we are the unordered
   1708           // or ordered version of the opcode.
   1709           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
   1710           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
   1711           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
   1712           break;
   1713         }
   1714         // Fallthrough if we are unsigned integer.
   1715     case ISD::SETLE:
   1716     case ISD::SETGT:
   1717     case ISD::SETGE:
   1718     case ISD::SETLT:
   1719       // We only support using the inverted operation, which is computed above
   1720       // and not a different manner of supporting expanding these cases.
   1721       llvm_unreachable("Don't know how to expand this condition!");
   1722     case ISD::SETNE:
   1723     case ISD::SETEQ:
   1724       // Try inverting the result of the inverse condition.
   1725       InvCC = CCCode == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ;
   1726       if (TLI.isCondCodeLegal(InvCC, OpVT)) {
   1727         CC = DAG.getCondCode(InvCC);
   1728         NeedInvert = true;
   1729         return true;
   1730       }
   1731       // If inverting the condition didn't work then we have no means to expand
   1732       // the condition.
   1733       llvm_unreachable("Don't know how to expand this condition!");
   1734     }
   1735 
   1736     SDValue SetCC1, SetCC2;
   1737     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
   1738       // If we aren't the ordered or unorder operation,
   1739       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
   1740       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1);
   1741       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2);
   1742     } else {
   1743       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
   1744       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1);
   1745       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2);
   1746     }
   1747     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
   1748     RHS = SDValue();
   1749     CC  = SDValue();
   1750     return true;
   1751   }
   1752   }
   1753   return false;
   1754 }
   1755 
   1756 /// EmitStackConvert - Emit a store/load combination to the stack.  This stores
   1757 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
   1758 /// a load from the stack slot to DestVT, extending it if needed.
   1759 /// The resultant code need not be legal.
   1760 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp,
   1761                                                EVT SlotVT,
   1762                                                EVT DestVT,
   1763                                                SDLoc dl) {
   1764   // Create the stack frame object.
   1765   unsigned SrcAlign =
   1766     TLI.getDataLayout()->getPrefTypeAlignment(SrcOp.getValueType().
   1767                                               getTypeForEVT(*DAG.getContext()));
   1768   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
   1769 
   1770   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
   1771   int SPFI = StackPtrFI->getIndex();
   1772   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
   1773 
   1774   unsigned SrcSize = SrcOp.getValueType().getSizeInBits();
   1775   unsigned SlotSize = SlotVT.getSizeInBits();
   1776   unsigned DestSize = DestVT.getSizeInBits();
   1777   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
   1778   unsigned DestAlign = TLI.getDataLayout()->getPrefTypeAlignment(DestType);
   1779 
   1780   // Emit a store to the stack slot.  Use a truncstore if the input value is
   1781   // later than DestVT.
   1782   SDValue Store;
   1783 
   1784   if (SrcSize > SlotSize)
   1785     Store = DAG.getTruncStore(DAG.getEntryNode(), dl, SrcOp, FIPtr,
   1786                               PtrInfo, SlotVT, false, false, SrcAlign);
   1787   else {
   1788     assert(SrcSize == SlotSize && "Invalid store");
   1789     Store = DAG.getStore(DAG.getEntryNode(), dl, SrcOp, FIPtr,
   1790                          PtrInfo, false, false, SrcAlign);
   1791   }
   1792 
   1793   // Result is a load from the stack slot.
   1794   if (SlotSize == DestSize)
   1795     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo,
   1796                        false, false, false, DestAlign);
   1797 
   1798   assert(SlotSize < DestSize && "Unknown extension!");
   1799   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr,
   1800                         PtrInfo, SlotVT, false, false, DestAlign);
   1801 }
   1802 
   1803 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
   1804   SDLoc dl(Node);
   1805   // Create a vector sized/aligned stack slot, store the value to element #0,
   1806   // then load the whole vector back out.
   1807   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
   1808 
   1809   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
   1810   int SPFI = StackPtrFI->getIndex();
   1811 
   1812   SDValue Ch = DAG.getTruncStore(DAG.getEntryNode(), dl, Node->getOperand(0),
   1813                                  StackPtr,
   1814                                  MachinePointerInfo::getFixedStack(SPFI),
   1815                                  Node->getValueType(0).getVectorElementType(),
   1816                                  false, false, 0);
   1817   return DAG.getLoad(Node->getValueType(0), dl, Ch, StackPtr,
   1818                      MachinePointerInfo::getFixedStack(SPFI),
   1819                      false, false, false, 0);
   1820 }
   1821 
   1822 static bool
   1823 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
   1824                      const TargetLowering &TLI, SDValue &Res) {
   1825   unsigned NumElems = Node->getNumOperands();
   1826   SDLoc dl(Node);
   1827   EVT VT = Node->getValueType(0);
   1828 
   1829   // Try to group the scalars into pairs, shuffle the pairs together, then
   1830   // shuffle the pairs of pairs together, etc. until the vector has
   1831   // been built. This will work only if all of the necessary shuffle masks
   1832   // are legal.
   1833 
   1834   // We do this in two phases; first to check the legality of the shuffles,
   1835   // and next, assuming that all shuffles are legal, to create the new nodes.
   1836   for (int Phase = 0; Phase < 2; ++Phase) {
   1837     SmallVector<std::pair<SDValue, SmallVector<int, 16> >, 16> IntermedVals,
   1838                                                                NewIntermedVals;
   1839     for (unsigned i = 0; i < NumElems; ++i) {
   1840       SDValue V = Node->getOperand(i);
   1841       if (V.getOpcode() == ISD::UNDEF)
   1842         continue;
   1843 
   1844       SDValue Vec;
   1845       if (Phase)
   1846         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
   1847       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
   1848     }
   1849 
   1850     while (IntermedVals.size() > 2) {
   1851       NewIntermedVals.clear();
   1852       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
   1853         // This vector and the next vector are shuffled together (simply to
   1854         // append the one to the other).
   1855         SmallVector<int, 16> ShuffleVec(NumElems, -1);
   1856 
   1857         SmallVector<int, 16> FinalIndices;
   1858         FinalIndices.reserve(IntermedVals[i].second.size() +
   1859                              IntermedVals[i+1].second.size());
   1860 
   1861         int k = 0;
   1862         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
   1863              ++j, ++k) {
   1864           ShuffleVec[k] = j;
   1865           FinalIndices.push_back(IntermedVals[i].second[j]);
   1866         }
   1867         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
   1868              ++j, ++k) {
   1869           ShuffleVec[k] = NumElems + j;
   1870           FinalIndices.push_back(IntermedVals[i+1].second[j]);
   1871         }
   1872 
   1873         SDValue Shuffle;
   1874         if (Phase)
   1875           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
   1876                                          IntermedVals[i+1].first,
   1877                                          ShuffleVec.data());
   1878         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
   1879           return false;
   1880         NewIntermedVals.push_back(std::make_pair(Shuffle, FinalIndices));
   1881       }
   1882 
   1883       // If we had an odd number of defined values, then append the last
   1884       // element to the array of new vectors.
   1885       if ((IntermedVals.size() & 1) != 0)
   1886         NewIntermedVals.push_back(IntermedVals.back());
   1887 
   1888       IntermedVals.swap(NewIntermedVals);
   1889     }
   1890 
   1891     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
   1892            "Invalid number of intermediate vectors");
   1893     SDValue Vec1 = IntermedVals[0].first;
   1894     SDValue Vec2;
   1895     if (IntermedVals.size() > 1)
   1896       Vec2 = IntermedVals[1].first;
   1897     else if (Phase)
   1898       Vec2 = DAG.getUNDEF(VT);
   1899 
   1900     SmallVector<int, 16> ShuffleVec(NumElems, -1);
   1901     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
   1902       ShuffleVec[IntermedVals[0].second[i]] = i;
   1903     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
   1904       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
   1905 
   1906     if (Phase)
   1907       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec.data());
   1908     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
   1909       return false;
   1910   }
   1911 
   1912   return true;
   1913 }
   1914 
   1915 /// ExpandBUILD_VECTOR - Expand a BUILD_VECTOR node on targets that don't
   1916 /// support the operation, but do support the resultant vector type.
   1917 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
   1918   unsigned NumElems = Node->getNumOperands();
   1919   SDValue Value1, Value2;
   1920   SDLoc dl(Node);
   1921   EVT VT = Node->getValueType(0);
   1922   EVT OpVT = Node->getOperand(0).getValueType();
   1923   EVT EltVT = VT.getVectorElementType();
   1924 
   1925   // If the only non-undef value is the low element, turn this into a
   1926   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
   1927   bool isOnlyLowElement = true;
   1928   bool MoreThanTwoValues = false;
   1929   bool isConstant = true;
   1930   for (unsigned i = 0; i < NumElems; ++i) {
   1931     SDValue V = Node->getOperand(i);
   1932     if (V.getOpcode() == ISD::UNDEF)
   1933       continue;
   1934     if (i > 0)
   1935       isOnlyLowElement = false;
   1936     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
   1937       isConstant = false;
   1938 
   1939     if (!Value1.getNode()) {
   1940       Value1 = V;
   1941     } else if (!Value2.getNode()) {
   1942       if (V != Value1)
   1943         Value2 = V;
   1944     } else if (V != Value1 && V != Value2) {
   1945       MoreThanTwoValues = true;
   1946     }
   1947   }
   1948 
   1949   if (!Value1.getNode())
   1950     return DAG.getUNDEF(VT);
   1951 
   1952   if (isOnlyLowElement)
   1953     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
   1954 
   1955   // If all elements are constants, create a load from the constant pool.
   1956   if (isConstant) {
   1957     SmallVector<Constant*, 16> CV;
   1958     for (unsigned i = 0, e = NumElems; i != e; ++i) {
   1959       if (ConstantFPSDNode *V =
   1960           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
   1961         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
   1962       } else if (ConstantSDNode *V =
   1963                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
   1964         if (OpVT==EltVT)
   1965           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
   1966         else {
   1967           // If OpVT and EltVT don't match, EltVT is not legal and the
   1968           // element values have been promoted/truncated earlier.  Undo this;
   1969           // we don't want a v16i8 to become a v16i32 for example.
   1970           const ConstantInt *CI = V->getConstantIntValue();
   1971           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
   1972                                         CI->getZExtValue()));
   1973         }
   1974       } else {
   1975         assert(Node->getOperand(i).getOpcode() == ISD::UNDEF);
   1976         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
   1977         CV.push_back(UndefValue::get(OpNTy));
   1978       }
   1979     }
   1980     Constant *CP = ConstantVector::get(CV);
   1981     SDValue CPIdx = DAG.getConstantPool(CP, TLI.getPointerTy());
   1982     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
   1983     return DAG.getLoad(VT, dl, DAG.getEntryNode(), CPIdx,
   1984                        MachinePointerInfo::getConstantPool(),
   1985                        false, false, false, Alignment);
   1986   }
   1987 
   1988   SmallSet<SDValue, 16> DefinedValues;
   1989   for (unsigned i = 0; i < NumElems; ++i) {
   1990     if (Node->getOperand(i).getOpcode() == ISD::UNDEF)
   1991       continue;
   1992     DefinedValues.insert(Node->getOperand(i));
   1993   }
   1994 
   1995   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
   1996     if (!MoreThanTwoValues) {
   1997       SmallVector<int, 8> ShuffleVec(NumElems, -1);
   1998       for (unsigned i = 0; i < NumElems; ++i) {
   1999         SDValue V = Node->getOperand(i);
   2000         if (V.getOpcode() == ISD::UNDEF)
   2001           continue;
   2002         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
   2003       }
   2004       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
   2005         // Get the splatted value into the low element of a vector register.
   2006         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
   2007         SDValue Vec2;
   2008         if (Value2.getNode())
   2009           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
   2010         else
   2011           Vec2 = DAG.getUNDEF(VT);
   2012 
   2013         // Return shuffle(LowValVec, undef, <0,0,0,0>)
   2014         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec.data());
   2015       }
   2016     } else {
   2017       SDValue Res;
   2018       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
   2019         return Res;
   2020     }
   2021   }
   2022 
   2023   // Otherwise, we can't handle this case efficiently.
   2024   return ExpandVectorBuildThroughStack(Node);
   2025 }
   2026 
   2027 // ExpandLibCall - Expand a node into a call to a libcall.  If the result value
   2028 // does not fit into a register, return the lo part and set the hi part to the
   2029 // by-reg argument.  If it does fit into a single register, return the result
   2030 // and leave the Hi part unset.
   2031 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
   2032                                             bool isSigned) {
   2033   TargetLowering::ArgListTy Args;
   2034   TargetLowering::ArgListEntry Entry;
   2035   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
   2036     EVT ArgVT = Node->getOperand(i).getValueType();
   2037     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
   2038     Entry.Node = Node->getOperand(i); Entry.Ty = ArgTy;
   2039     Entry.isSExt = isSigned;
   2040     Entry.isZExt = !isSigned;
   2041     Args.push_back(Entry);
   2042   }
   2043   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   2044                                          TLI.getPointerTy());
   2045 
   2046   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
   2047 
   2048   // By default, the input chain to this libcall is the entry node of the
   2049   // function. If the libcall is going to be emitted as a tail call then
   2050   // TLI.isUsedByReturnOnly will change it to the right chain if the return
   2051   // node which is being folded has a non-entry input chain.
   2052   SDValue InChain = DAG.getEntryNode();
   2053 
   2054   // isTailCall may be true since the callee does not reference caller stack
   2055   // frame. Check if it's in the right position.
   2056   SDValue TCChain = InChain;
   2057   bool isTailCall = TLI.isInTailCallPosition(DAG, Node, TCChain);
   2058   if (isTailCall)
   2059     InChain = TCChain;
   2060 
   2061   TargetLowering::CallLoweringInfo CLI(DAG);
   2062   CLI.setDebugLoc(SDLoc(Node)).setChain(InChain)
   2063     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0)
   2064     .setTailCall(isTailCall).setSExtResult(isSigned).setZExtResult(!isSigned);
   2065 
   2066   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
   2067 
   2068   if (!CallInfo.second.getNode())
   2069     // It's a tailcall, return the chain (which is the DAG root).
   2070     return DAG.getRoot();
   2071 
   2072   return CallInfo.first;
   2073 }
   2074 
   2075 /// ExpandLibCall - Generate a libcall taking the given operands as arguments
   2076 /// and returning a result of type RetVT.
   2077 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, EVT RetVT,
   2078                                             const SDValue *Ops, unsigned NumOps,
   2079                                             bool isSigned, SDLoc dl) {
   2080   TargetLowering::ArgListTy Args;
   2081   Args.reserve(NumOps);
   2082 
   2083   TargetLowering::ArgListEntry Entry;
   2084   for (unsigned i = 0; i != NumOps; ++i) {
   2085     Entry.Node = Ops[i];
   2086     Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
   2087     Entry.isSExt = isSigned;
   2088     Entry.isZExt = !isSigned;
   2089     Args.push_back(Entry);
   2090   }
   2091   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   2092                                          TLI.getPointerTy());
   2093 
   2094   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
   2095 
   2096   TargetLowering::CallLoweringInfo CLI(DAG);
   2097   CLI.setDebugLoc(dl).setChain(DAG.getEntryNode())
   2098     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0)
   2099     .setSExtResult(isSigned).setZExtResult(!isSigned);
   2100 
   2101   std::pair<SDValue,SDValue> CallInfo = TLI.LowerCallTo(CLI);
   2102 
   2103   return CallInfo.first;
   2104 }
   2105 
   2106 // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to
   2107 // ExpandLibCall except that the first operand is the in-chain.
   2108 std::pair<SDValue, SDValue>
   2109 SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
   2110                                          SDNode *Node,
   2111                                          bool isSigned) {
   2112   SDValue InChain = Node->getOperand(0);
   2113 
   2114   TargetLowering::ArgListTy Args;
   2115   TargetLowering::ArgListEntry Entry;
   2116   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
   2117     EVT ArgVT = Node->getOperand(i).getValueType();
   2118     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
   2119     Entry.Node = Node->getOperand(i);
   2120     Entry.Ty = ArgTy;
   2121     Entry.isSExt = isSigned;
   2122     Entry.isZExt = !isSigned;
   2123     Args.push_back(Entry);
   2124   }
   2125   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   2126                                          TLI.getPointerTy());
   2127 
   2128   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
   2129 
   2130   TargetLowering::CallLoweringInfo CLI(DAG);
   2131   CLI.setDebugLoc(SDLoc(Node)).setChain(InChain)
   2132     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0)
   2133     .setSExtResult(isSigned).setZExtResult(!isSigned);
   2134 
   2135   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
   2136 
   2137   return CallInfo;
   2138 }
   2139 
   2140 SDValue SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
   2141                                               RTLIB::Libcall Call_F32,
   2142                                               RTLIB::Libcall Call_F64,
   2143                                               RTLIB::Libcall Call_F80,
   2144                                               RTLIB::Libcall Call_F128,
   2145                                               RTLIB::Libcall Call_PPCF128) {
   2146   RTLIB::Libcall LC;
   2147   switch (Node->getSimpleValueType(0).SimpleTy) {
   2148   default: llvm_unreachable("Unexpected request for libcall!");
   2149   case MVT::f32: LC = Call_F32; break;
   2150   case MVT::f64: LC = Call_F64; break;
   2151   case MVT::f80: LC = Call_F80; break;
   2152   case MVT::f128: LC = Call_F128; break;
   2153   case MVT::ppcf128: LC = Call_PPCF128; break;
   2154   }
   2155   return ExpandLibCall(LC, Node, false);
   2156 }
   2157 
   2158 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
   2159                                                RTLIB::Libcall Call_I8,
   2160                                                RTLIB::Libcall Call_I16,
   2161                                                RTLIB::Libcall Call_I32,
   2162                                                RTLIB::Libcall Call_I64,
   2163                                                RTLIB::Libcall Call_I128) {
   2164   RTLIB::Libcall LC;
   2165   switch (Node->getSimpleValueType(0).SimpleTy) {
   2166   default: llvm_unreachable("Unexpected request for libcall!");
   2167   case MVT::i8:   LC = Call_I8; break;
   2168   case MVT::i16:  LC = Call_I16; break;
   2169   case MVT::i32:  LC = Call_I32; break;
   2170   case MVT::i64:  LC = Call_I64; break;
   2171   case MVT::i128: LC = Call_I128; break;
   2172   }
   2173   return ExpandLibCall(LC, Node, isSigned);
   2174 }
   2175 
   2176 /// isDivRemLibcallAvailable - Return true if divmod libcall is available.
   2177 static bool isDivRemLibcallAvailable(SDNode *Node, bool isSigned,
   2178                                      const TargetLowering &TLI) {
   2179   RTLIB::Libcall LC;
   2180   switch (Node->getSimpleValueType(0).SimpleTy) {
   2181   default: llvm_unreachable("Unexpected request for libcall!");
   2182   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
   2183   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
   2184   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
   2185   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
   2186   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
   2187   }
   2188 
   2189   return TLI.getLibcallName(LC) != nullptr;
   2190 }
   2191 
   2192 /// useDivRem - Only issue divrem libcall if both quotient and remainder are
   2193 /// needed.
   2194 static bool useDivRem(SDNode *Node, bool isSigned, bool isDIV) {
   2195   // The other use might have been replaced with a divrem already.
   2196   unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
   2197   unsigned OtherOpcode = 0;
   2198   if (isSigned)
   2199     OtherOpcode = isDIV ? ISD::SREM : ISD::SDIV;
   2200   else
   2201     OtherOpcode = isDIV ? ISD::UREM : ISD::UDIV;
   2202 
   2203   SDValue Op0 = Node->getOperand(0);
   2204   SDValue Op1 = Node->getOperand(1);
   2205   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
   2206          UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
   2207     SDNode *User = *UI;
   2208     if (User == Node)
   2209       continue;
   2210     if ((User->getOpcode() == OtherOpcode || User->getOpcode() == DivRemOpc) &&
   2211         User->getOperand(0) == Op0 &&
   2212         User->getOperand(1) == Op1)
   2213       return true;
   2214   }
   2215   return false;
   2216 }
   2217 
   2218 /// ExpandDivRemLibCall - Issue libcalls to __{u}divmod to compute div / rem
   2219 /// pairs.
   2220 void
   2221 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
   2222                                           SmallVectorImpl<SDValue> &Results) {
   2223   unsigned Opcode = Node->getOpcode();
   2224   bool isSigned = Opcode == ISD::SDIVREM;
   2225 
   2226   RTLIB::Libcall LC;
   2227   switch (Node->getSimpleValueType(0).SimpleTy) {
   2228   default: llvm_unreachable("Unexpected request for libcall!");
   2229   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
   2230   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
   2231   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
   2232   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
   2233   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
   2234   }
   2235 
   2236   // The input chain to this libcall is the entry node of the function.
   2237   // Legalizing the call will automatically add the previous call to the
   2238   // dependence.
   2239   SDValue InChain = DAG.getEntryNode();
   2240 
   2241   EVT RetVT = Node->getValueType(0);
   2242   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
   2243 
   2244   TargetLowering::ArgListTy Args;
   2245   TargetLowering::ArgListEntry Entry;
   2246   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
   2247     EVT ArgVT = Node->getOperand(i).getValueType();
   2248     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
   2249     Entry.Node = Node->getOperand(i); Entry.Ty = ArgTy;
   2250     Entry.isSExt = isSigned;
   2251     Entry.isZExt = !isSigned;
   2252     Args.push_back(Entry);
   2253   }
   2254 
   2255   // Also pass the return address of the remainder.
   2256   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
   2257   Entry.Node = FIPtr;
   2258   Entry.Ty = RetTy->getPointerTo();
   2259   Entry.isSExt = isSigned;
   2260   Entry.isZExt = !isSigned;
   2261   Args.push_back(Entry);
   2262 
   2263   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   2264                                          TLI.getPointerTy());
   2265 
   2266   SDLoc dl(Node);
   2267   TargetLowering::CallLoweringInfo CLI(DAG);
   2268   CLI.setDebugLoc(dl).setChain(InChain)
   2269     .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0)
   2270     .setSExtResult(isSigned).setZExtResult(!isSigned);
   2271 
   2272   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
   2273 
   2274   // Remainder is loaded back from the stack frame.
   2275   SDValue Rem = DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr,
   2276                             MachinePointerInfo(), false, false, false, 0);
   2277   Results.push_back(CallInfo.first);
   2278   Results.push_back(Rem);
   2279 }
   2280 
   2281 /// isSinCosLibcallAvailable - Return true if sincos libcall is available.
   2282 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
   2283   RTLIB::Libcall LC;
   2284   switch (Node->getSimpleValueType(0).SimpleTy) {
   2285   default: llvm_unreachable("Unexpected request for libcall!");
   2286   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
   2287   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
   2288   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
   2289   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
   2290   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
   2291   }
   2292   return TLI.getLibcallName(LC) != nullptr;
   2293 }
   2294 
   2295 /// canCombineSinCosLibcall - Return true if sincos libcall is available and
   2296 /// can be used to combine sin and cos.
   2297 static bool canCombineSinCosLibcall(SDNode *Node, const TargetLowering &TLI,
   2298                                     const TargetMachine &TM) {
   2299   if (!isSinCosLibcallAvailable(Node, TLI))
   2300     return false;
   2301   // GNU sin/cos functions set errno while sincos does not. Therefore
   2302   // combining sin and cos is only safe if unsafe-fpmath is enabled.
   2303   bool isGNU = Triple(TM.getTargetTriple()).getEnvironment() == Triple::GNU;
   2304   if (isGNU && !TM.Options.UnsafeFPMath)
   2305     return false;
   2306   return true;
   2307 }
   2308 
   2309 /// useSinCos - Only issue sincos libcall if both sin and cos are
   2310 /// needed.
   2311 static bool useSinCos(SDNode *Node) {
   2312   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
   2313     ? ISD::FCOS : ISD::FSIN;
   2314 
   2315   SDValue Op0 = Node->getOperand(0);
   2316   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
   2317        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
   2318     SDNode *User = *UI;
   2319     if (User == Node)
   2320       continue;
   2321     // The other user might have been turned into sincos already.
   2322     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
   2323       return true;
   2324   }
   2325   return false;
   2326 }
   2327 
   2328 /// ExpandSinCosLibCall - Issue libcalls to sincos to compute sin / cos
   2329 /// pairs.
   2330 void
   2331 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
   2332                                           SmallVectorImpl<SDValue> &Results) {
   2333   RTLIB::Libcall LC;
   2334   switch (Node->getSimpleValueType(0).SimpleTy) {
   2335   default: llvm_unreachable("Unexpected request for libcall!");
   2336   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
   2337   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
   2338   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
   2339   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
   2340   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
   2341   }
   2342 
   2343   // The input chain to this libcall is the entry node of the function.
   2344   // Legalizing the call will automatically add the previous call to the
   2345   // dependence.
   2346   SDValue InChain = DAG.getEntryNode();
   2347 
   2348   EVT RetVT = Node->getValueType(0);
   2349   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
   2350 
   2351   TargetLowering::ArgListTy Args;
   2352   TargetLowering::ArgListEntry Entry;
   2353 
   2354   // Pass the argument.
   2355   Entry.Node = Node->getOperand(0);
   2356   Entry.Ty = RetTy;
   2357   Entry.isSExt = false;
   2358   Entry.isZExt = false;
   2359   Args.push_back(Entry);
   2360 
   2361   // Pass the return address of sin.
   2362   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
   2363   Entry.Node = SinPtr;
   2364   Entry.Ty = RetTy->getPointerTo();
   2365   Entry.isSExt = false;
   2366   Entry.isZExt = false;
   2367   Args.push_back(Entry);
   2368 
   2369   // Also pass the return address of the cos.
   2370   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
   2371   Entry.Node = CosPtr;
   2372   Entry.Ty = RetTy->getPointerTo();
   2373   Entry.isSExt = false;
   2374   Entry.isZExt = false;
   2375   Args.push_back(Entry);
   2376 
   2377   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   2378                                          TLI.getPointerTy());
   2379 
   2380   SDLoc dl(Node);
   2381   TargetLowering::CallLoweringInfo CLI(DAG);
   2382   CLI.setDebugLoc(dl).setChain(InChain)
   2383     .setCallee(TLI.getLibcallCallingConv(LC),
   2384                Type::getVoidTy(*DAG.getContext()), Callee, std::move(Args), 0);
   2385 
   2386   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
   2387 
   2388   Results.push_back(DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr,
   2389                                 MachinePointerInfo(), false, false, false, 0));
   2390   Results.push_back(DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr,
   2391                                 MachinePointerInfo(), false, false, false, 0));
   2392 }
   2393 
   2394 /// ExpandLegalINT_TO_FP - This function is responsible for legalizing a
   2395 /// INT_TO_FP operation of the specified operand when the target requests that
   2396 /// we expand it.  At this point, we know that the result and operand types are
   2397 /// legal for the target.
   2398 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned,
   2399                                                    SDValue Op0,
   2400                                                    EVT DestVT,
   2401                                                    SDLoc dl) {
   2402   if (Op0.getValueType() == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
   2403     // simple 32-bit [signed|unsigned] integer to float/double expansion
   2404 
   2405     // Get the stack frame index of a 8 byte buffer.
   2406     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
   2407 
   2408     // word offset constant for Hi/Lo address computation
   2409     SDValue WordOff = DAG.getConstant(sizeof(int), StackSlot.getValueType());
   2410     // set up Hi and Lo (into buffer) address based on endian
   2411     SDValue Hi = StackSlot;
   2412     SDValue Lo = DAG.getNode(ISD::ADD, dl, StackSlot.getValueType(),
   2413                              StackSlot, WordOff);
   2414     if (TLI.isLittleEndian())
   2415       std::swap(Hi, Lo);
   2416 
   2417     // if signed map to unsigned space
   2418     SDValue Op0Mapped;
   2419     if (isSigned) {
   2420       // constant used to invert sign bit (signed to unsigned mapping)
   2421       SDValue SignBit = DAG.getConstant(0x80000000u, MVT::i32);
   2422       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
   2423     } else {
   2424       Op0Mapped = Op0;
   2425     }
   2426     // store the lo of the constructed double - based on integer input
   2427     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl,
   2428                                   Op0Mapped, Lo, MachinePointerInfo(),
   2429                                   false, false, 0);
   2430     // initial hi portion of constructed double
   2431     SDValue InitialHi = DAG.getConstant(0x43300000u, MVT::i32);
   2432     // store the hi of the constructed double - biased exponent
   2433     SDValue Store2 = DAG.getStore(Store1, dl, InitialHi, Hi,
   2434                                   MachinePointerInfo(),
   2435                                   false, false, 0);
   2436     // load the constructed double
   2437     SDValue Load = DAG.getLoad(MVT::f64, dl, Store2, StackSlot,
   2438                                MachinePointerInfo(), false, false, false, 0);
   2439     // FP constant to bias correct the final result
   2440     SDValue Bias = DAG.getConstantFP(isSigned ?
   2441                                      BitsToDouble(0x4330000080000000ULL) :
   2442                                      BitsToDouble(0x4330000000000000ULL),
   2443                                      MVT::f64);
   2444     // subtract the bias
   2445     SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
   2446     // final result
   2447     SDValue Result;
   2448     // handle final rounding
   2449     if (DestVT == MVT::f64) {
   2450       // do nothing
   2451       Result = Sub;
   2452     } else if (DestVT.bitsLT(MVT::f64)) {
   2453       Result = DAG.getNode(ISD::FP_ROUND, dl, DestVT, Sub,
   2454                            DAG.getIntPtrConstant(0));
   2455     } else if (DestVT.bitsGT(MVT::f64)) {
   2456       Result = DAG.getNode(ISD::FP_EXTEND, dl, DestVT, Sub);
   2457     }
   2458     return Result;
   2459   }
   2460   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
   2461   // Code below here assumes !isSigned without checking again.
   2462 
   2463   // Implementation of unsigned i64 to f64 following the algorithm in
   2464   // __floatundidf in compiler_rt. This implementation has the advantage
   2465   // of performing rounding correctly, both in the default rounding mode
   2466   // and in all alternate rounding modes.
   2467   // TODO: Generalize this for use with other types.
   2468   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f64) {
   2469     SDValue TwoP52 =
   2470       DAG.getConstant(UINT64_C(0x4330000000000000), MVT::i64);
   2471     SDValue TwoP84PlusTwoP52 =
   2472       DAG.getConstantFP(BitsToDouble(UINT64_C(0x4530000000100000)), MVT::f64);
   2473     SDValue TwoP84 =
   2474       DAG.getConstant(UINT64_C(0x4530000000000000), MVT::i64);
   2475 
   2476     SDValue Lo = DAG.getZeroExtendInReg(Op0, dl, MVT::i32);
   2477     SDValue Hi = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0,
   2478                              DAG.getConstant(32, MVT::i64));
   2479     SDValue LoOr = DAG.getNode(ISD::OR, dl, MVT::i64, Lo, TwoP52);
   2480     SDValue HiOr = DAG.getNode(ISD::OR, dl, MVT::i64, Hi, TwoP84);
   2481     SDValue LoFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, LoOr);
   2482     SDValue HiFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, HiOr);
   2483     SDValue HiSub = DAG.getNode(ISD::FSUB, dl, MVT::f64, HiFlt,
   2484                                 TwoP84PlusTwoP52);
   2485     return DAG.getNode(ISD::FADD, dl, MVT::f64, LoFlt, HiSub);
   2486   }
   2487 
   2488   // Implementation of unsigned i64 to f32.
   2489   // TODO: Generalize this for use with other types.
   2490   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f32) {
   2491     // For unsigned conversions, convert them to signed conversions using the
   2492     // algorithm from the x86_64 __floatundidf in compiler_rt.
   2493     if (!isSigned) {
   2494       SDValue Fast = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Op0);
   2495 
   2496       SDValue ShiftConst =
   2497           DAG.getConstant(1, TLI.getShiftAmountTy(Op0.getValueType()));
   2498       SDValue Shr = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0, ShiftConst);
   2499       SDValue AndConst = DAG.getConstant(1, MVT::i64);
   2500       SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0, AndConst);
   2501       SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And, Shr);
   2502 
   2503       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Or);
   2504       SDValue Slow = DAG.getNode(ISD::FADD, dl, MVT::f32, SignCvt, SignCvt);
   2505 
   2506       // TODO: This really should be implemented using a branch rather than a
   2507       // select.  We happen to get lucky and machinesink does the right
   2508       // thing most of the time.  This would be a good candidate for a
   2509       //pseudo-op, or, even better, for whole-function isel.
   2510       SDValue SignBitTest = DAG.getSetCC(dl, getSetCCResultType(MVT::i64),
   2511         Op0, DAG.getConstant(0, MVT::i64), ISD::SETLT);
   2512       return DAG.getSelect(dl, MVT::f32, SignBitTest, Slow, Fast);
   2513     }
   2514 
   2515     // Otherwise, implement the fully general conversion.
   2516 
   2517     SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
   2518          DAG.getConstant(UINT64_C(0xfffffffffffff800), MVT::i64));
   2519     SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And,
   2520          DAG.getConstant(UINT64_C(0x800), MVT::i64));
   2521     SDValue And2 = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
   2522          DAG.getConstant(UINT64_C(0x7ff), MVT::i64));
   2523     SDValue Ne = DAG.getSetCC(dl, getSetCCResultType(MVT::i64),
   2524                    And2, DAG.getConstant(UINT64_C(0), MVT::i64), ISD::SETNE);
   2525     SDValue Sel = DAG.getSelect(dl, MVT::i64, Ne, Or, Op0);
   2526     SDValue Ge = DAG.getSetCC(dl, getSetCCResultType(MVT::i64),
   2527                    Op0, DAG.getConstant(UINT64_C(0x0020000000000000), MVT::i64),
   2528                    ISD::SETUGE);
   2529     SDValue Sel2 = DAG.getSelect(dl, MVT::i64, Ge, Sel, Op0);
   2530     EVT SHVT = TLI.getShiftAmountTy(Sel2.getValueType());
   2531 
   2532     SDValue Sh = DAG.getNode(ISD::SRL, dl, MVT::i64, Sel2,
   2533                              DAG.getConstant(32, SHVT));
   2534     SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sh);
   2535     SDValue Fcvt = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Trunc);
   2536     SDValue TwoP32 =
   2537       DAG.getConstantFP(BitsToDouble(UINT64_C(0x41f0000000000000)), MVT::f64);
   2538     SDValue Fmul = DAG.getNode(ISD::FMUL, dl, MVT::f64, TwoP32, Fcvt);
   2539     SDValue Lo = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sel2);
   2540     SDValue Fcvt2 = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Lo);
   2541     SDValue Fadd = DAG.getNode(ISD::FADD, dl, MVT::f64, Fmul, Fcvt2);
   2542     return DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Fadd,
   2543                        DAG.getIntPtrConstant(0));
   2544   }
   2545 
   2546   SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
   2547 
   2548   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(Op0.getValueType()),
   2549                                  Op0, DAG.getConstant(0, Op0.getValueType()),
   2550                                  ISD::SETLT);
   2551   SDValue Zero = DAG.getIntPtrConstant(0), Four = DAG.getIntPtrConstant(4);
   2552   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
   2553                                     SignSet, Four, Zero);
   2554 
   2555   // If the sign bit of the integer is set, the large number will be treated
   2556   // as a negative number.  To counteract this, the dynamic code adds an
   2557   // offset depending on the data type.
   2558   uint64_t FF;
   2559   switch (Op0.getSimpleValueType().SimpleTy) {
   2560   default: llvm_unreachable("Unsupported integer type!");
   2561   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
   2562   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
   2563   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
   2564   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
   2565   }
   2566   if (TLI.isLittleEndian()) FF <<= 32;
   2567   Constant *FudgeFactor = ConstantInt::get(
   2568                                        Type::getInt64Ty(*DAG.getContext()), FF);
   2569 
   2570   SDValue CPIdx = DAG.getConstantPool(FudgeFactor, TLI.getPointerTy());
   2571   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
   2572   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
   2573   Alignment = std::min(Alignment, 4u);
   2574   SDValue FudgeInReg;
   2575   if (DestVT == MVT::f32)
   2576     FudgeInReg = DAG.getLoad(MVT::f32, dl, DAG.getEntryNode(), CPIdx,
   2577                              MachinePointerInfo::getConstantPool(),
   2578                              false, false, false, Alignment);
   2579   else {
   2580     SDValue Load = DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT,
   2581                                   DAG.getEntryNode(), CPIdx,
   2582                                   MachinePointerInfo::getConstantPool(),
   2583                                   MVT::f32, false, false, Alignment);
   2584     HandleSDNode Handle(Load);
   2585     LegalizeOp(Load.getNode());
   2586     FudgeInReg = Handle.getValue();
   2587   }
   2588 
   2589   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
   2590 }
   2591 
   2592 /// PromoteLegalINT_TO_FP - This function is responsible for legalizing a
   2593 /// *INT_TO_FP operation of the specified operand when the target requests that
   2594 /// we promote it.  At this point, we know that the result and operand types are
   2595 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
   2596 /// operation that takes a larger input.
   2597 SDValue SelectionDAGLegalize::PromoteLegalINT_TO_FP(SDValue LegalOp,
   2598                                                     EVT DestVT,
   2599                                                     bool isSigned,
   2600                                                     SDLoc dl) {
   2601   // First step, figure out the appropriate *INT_TO_FP operation to use.
   2602   EVT NewInTy = LegalOp.getValueType();
   2603 
   2604   unsigned OpToUse = 0;
   2605 
   2606   // Scan for the appropriate larger type to use.
   2607   while (1) {
   2608     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
   2609     assert(NewInTy.isInteger() && "Ran out of possibilities!");
   2610 
   2611     // If the target supports SINT_TO_FP of this type, use it.
   2612     if (TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, NewInTy)) {
   2613       OpToUse = ISD::SINT_TO_FP;
   2614       break;
   2615     }
   2616     if (isSigned) continue;
   2617 
   2618     // If the target supports UINT_TO_FP of this type, use it.
   2619     if (TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, NewInTy)) {
   2620       OpToUse = ISD::UINT_TO_FP;
   2621       break;
   2622     }
   2623 
   2624     // Otherwise, try a larger type.
   2625   }
   2626 
   2627   // Okay, we found the operation and type to use.  Zero extend our input to the
   2628   // desired type then run the operation on it.
   2629   return DAG.getNode(OpToUse, dl, DestVT,
   2630                      DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
   2631                                  dl, NewInTy, LegalOp));
   2632 }
   2633 
   2634 /// PromoteLegalFP_TO_INT - This function is responsible for legalizing a
   2635 /// FP_TO_*INT operation of the specified operand when the target requests that
   2636 /// we promote it.  At this point, we know that the result and operand types are
   2637 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
   2638 /// operation that returns a larger result.
   2639 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDValue LegalOp,
   2640                                                     EVT DestVT,
   2641                                                     bool isSigned,
   2642                                                     SDLoc dl) {
   2643   // First step, figure out the appropriate FP_TO*INT operation to use.
   2644   EVT NewOutTy = DestVT;
   2645 
   2646   unsigned OpToUse = 0;
   2647 
   2648   // Scan for the appropriate larger type to use.
   2649   while (1) {
   2650     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
   2651     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
   2652 
   2653     // A larger signed type can hold all unsigned values of the requested type,
   2654     // so using FP_TO_SINT is valid
   2655     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NewOutTy)) {
   2656       OpToUse = ISD::FP_TO_SINT;
   2657       break;
   2658     }
   2659 
   2660     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
   2661     if (!isSigned && TLI.isOperationLegalOrCustom(ISD::FP_TO_UINT, NewOutTy)) {
   2662       OpToUse = ISD::FP_TO_UINT;
   2663       break;
   2664     }
   2665 
   2666     // Otherwise, try a larger type.
   2667   }
   2668 
   2669 
   2670   // Okay, we found the operation and type to use.
   2671   SDValue Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
   2672 
   2673   // Truncate the result of the extended FP_TO_*INT operation to the desired
   2674   // size.
   2675   return DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
   2676 }
   2677 
   2678 /// ExpandBSWAP - Open code the operations for BSWAP of the specified operation.
   2679 ///
   2680 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, SDLoc dl) {
   2681   EVT VT = Op.getValueType();
   2682   EVT SHVT = TLI.getShiftAmountTy(VT);
   2683   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
   2684   switch (VT.getSimpleVT().SimpleTy) {
   2685   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
   2686   case MVT::i16:
   2687     Tmp2 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2688     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2689     return DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
   2690   case MVT::i32:
   2691     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2692     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2693     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2694     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2695     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3, DAG.getConstant(0xFF0000, VT));
   2696     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, VT));
   2697     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
   2698     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
   2699     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
   2700   case MVT::i64:
   2701     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, SHVT));
   2702     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, SHVT));
   2703     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2704     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2705     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2706     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2707     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, SHVT));
   2708     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, SHVT));
   2709     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7, DAG.getConstant(255ULL<<48, VT));
   2710     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6, DAG.getConstant(255ULL<<40, VT));
   2711     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5, DAG.getConstant(255ULL<<32, VT));
   2712     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4, DAG.getConstant(255ULL<<24, VT));
   2713     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3, DAG.getConstant(255ULL<<16, VT));
   2714     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(255ULL<<8 , VT));
   2715     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
   2716     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
   2717     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
   2718     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
   2719     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
   2720     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
   2721     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
   2722   }
   2723 }
   2724 
   2725 /// ExpandBitCount - Expand the specified bitcount instruction into operations.
   2726 ///
   2727 SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
   2728                                              SDLoc dl) {
   2729   switch (Opc) {
   2730   default: llvm_unreachable("Cannot expand this yet!");
   2731   case ISD::CTPOP: {
   2732     EVT VT = Op.getValueType();
   2733     EVT ShVT = TLI.getShiftAmountTy(VT);
   2734     unsigned Len = VT.getSizeInBits();
   2735 
   2736     assert(VT.isInteger() && Len <= 128 && Len % 8 == 0 &&
   2737            "CTPOP not implemented for this type.");
   2738 
   2739     // This is the "best" algorithm from
   2740     // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
   2741 
   2742     SDValue Mask55 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x55)), VT);
   2743     SDValue Mask33 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x33)), VT);
   2744     SDValue Mask0F = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x0F)), VT);
   2745     SDValue Mask01 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x01)), VT);
   2746 
   2747     // v = v - ((v >> 1) & 0x55555555...)
   2748     Op = DAG.getNode(ISD::SUB, dl, VT, Op,
   2749                      DAG.getNode(ISD::AND, dl, VT,
   2750                                  DAG.getNode(ISD::SRL, dl, VT, Op,
   2751                                              DAG.getConstant(1, ShVT)),
   2752                                  Mask55));
   2753     // v = (v & 0x33333333...) + ((v >> 2) & 0x33333333...)
   2754     Op = DAG.getNode(ISD::ADD, dl, VT,
   2755                      DAG.getNode(ISD::AND, dl, VT, Op, Mask33),
   2756                      DAG.getNode(ISD::AND, dl, VT,
   2757                                  DAG.getNode(ISD::SRL, dl, VT, Op,
   2758                                              DAG.getConstant(2, ShVT)),
   2759                                  Mask33));
   2760     // v = (v + (v >> 4)) & 0x0F0F0F0F...
   2761     Op = DAG.getNode(ISD::AND, dl, VT,
   2762                      DAG.getNode(ISD::ADD, dl, VT, Op,
   2763                                  DAG.getNode(ISD::SRL, dl, VT, Op,
   2764                                              DAG.getConstant(4, ShVT))),
   2765                      Mask0F);
   2766     // v = (v * 0x01010101...) >> (Len - 8)
   2767     Op = DAG.getNode(ISD::SRL, dl, VT,
   2768                      DAG.getNode(ISD::MUL, dl, VT, Op, Mask01),
   2769                      DAG.getConstant(Len - 8, ShVT));
   2770 
   2771     return Op;
   2772   }
   2773   case ISD::CTLZ_ZERO_UNDEF:
   2774     // This trivially expands to CTLZ.
   2775     return DAG.getNode(ISD::CTLZ, dl, Op.getValueType(), Op);
   2776   case ISD::CTLZ: {
   2777     // for now, we do this:
   2778     // x = x | (x >> 1);
   2779     // x = x | (x >> 2);
   2780     // ...
   2781     // x = x | (x >>16);
   2782     // x = x | (x >>32); // for 64-bit input
   2783     // return popcount(~x);
   2784     //
   2785     // but see also: http://www.hackersdelight.org/HDcode/nlz.cc
   2786     EVT VT = Op.getValueType();
   2787     EVT ShVT = TLI.getShiftAmountTy(VT);
   2788     unsigned len = VT.getSizeInBits();
   2789     for (unsigned i = 0; (1U << i) <= (len / 2); ++i) {
   2790       SDValue Tmp3 = DAG.getConstant(1ULL << i, ShVT);
   2791       Op = DAG.getNode(ISD::OR, dl, VT, Op,
   2792                        DAG.getNode(ISD::SRL, dl, VT, Op, Tmp3));
   2793     }
   2794     Op = DAG.getNOT(dl, Op, VT);
   2795     return DAG.getNode(ISD::CTPOP, dl, VT, Op);
   2796   }
   2797   case ISD::CTTZ_ZERO_UNDEF:
   2798     // This trivially expands to CTTZ.
   2799     return DAG.getNode(ISD::CTTZ, dl, Op.getValueType(), Op);
   2800   case ISD::CTTZ: {
   2801     // for now, we use: { return popcount(~x & (x - 1)); }
   2802     // unless the target has ctlz but not ctpop, in which case we use:
   2803     // { return 32 - nlz(~x & (x-1)); }
   2804     // see also http://www.hackersdelight.org/HDcode/ntz.cc
   2805     EVT VT = Op.getValueType();
   2806     SDValue Tmp3 = DAG.getNode(ISD::AND, dl, VT,
   2807                                DAG.getNOT(dl, Op, VT),
   2808                                DAG.getNode(ISD::SUB, dl, VT, Op,
   2809                                            DAG.getConstant(1, VT)));
   2810     // If ISD::CTLZ is legal and CTPOP isn't, then do that instead.
   2811     if (!TLI.isOperationLegalOrCustom(ISD::CTPOP, VT) &&
   2812         TLI.isOperationLegalOrCustom(ISD::CTLZ, VT))
   2813       return DAG.getNode(ISD::SUB, dl, VT,
   2814                          DAG.getConstant(VT.getSizeInBits(), VT),
   2815                          DAG.getNode(ISD::CTLZ, dl, VT, Tmp3));
   2816     return DAG.getNode(ISD::CTPOP, dl, VT, Tmp3);
   2817   }
   2818   }
   2819 }
   2820 
   2821 std::pair <SDValue, SDValue> SelectionDAGLegalize::ExpandAtomic(SDNode *Node) {
   2822   unsigned Opc = Node->getOpcode();
   2823   MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
   2824   RTLIB::Libcall LC;
   2825 
   2826   switch (Opc) {
   2827   default:
   2828     llvm_unreachable("Unhandled atomic intrinsic Expand!");
   2829   case ISD::ATOMIC_SWAP:
   2830     switch (VT.SimpleTy) {
   2831     default: llvm_unreachable("Unexpected value type for atomic!");
   2832     case MVT::i8:  LC = RTLIB::SYNC_LOCK_TEST_AND_SET_1; break;
   2833     case MVT::i16: LC = RTLIB::SYNC_LOCK_TEST_AND_SET_2; break;
   2834     case MVT::i32: LC = RTLIB::SYNC_LOCK_TEST_AND_SET_4; break;
   2835     case MVT::i64: LC = RTLIB::SYNC_LOCK_TEST_AND_SET_8; break;
   2836     case MVT::i128:LC = RTLIB::SYNC_LOCK_TEST_AND_SET_16;break;
   2837     }
   2838     break;
   2839   case ISD::ATOMIC_CMP_SWAP:
   2840     switch (VT.SimpleTy) {
   2841     default: llvm_unreachable("Unexpected value type for atomic!");
   2842     case MVT::i8:  LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_1; break;
   2843     case MVT::i16: LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_2; break;
   2844     case MVT::i32: LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_4; break;
   2845     case MVT::i64: LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_8; break;
   2846     case MVT::i128:LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_16;break;
   2847     }
   2848     break;
   2849   case ISD::ATOMIC_LOAD_ADD:
   2850     switch (VT.SimpleTy) {
   2851     default: llvm_unreachable("Unexpected value type for atomic!");
   2852     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_ADD_1; break;
   2853     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_ADD_2; break;
   2854     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_ADD_4; break;
   2855     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_ADD_8; break;
   2856     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_ADD_16;break;
   2857     }
   2858     break;
   2859   case ISD::ATOMIC_LOAD_SUB:
   2860     switch (VT.SimpleTy) {
   2861     default: llvm_unreachable("Unexpected value type for atomic!");
   2862     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_SUB_1; break;
   2863     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_SUB_2; break;
   2864     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_SUB_4; break;
   2865     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_SUB_8; break;
   2866     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_SUB_16;break;
   2867     }
   2868     break;
   2869   case ISD::ATOMIC_LOAD_AND:
   2870     switch (VT.SimpleTy) {
   2871     default: llvm_unreachable("Unexpected value type for atomic!");
   2872     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_AND_1; break;
   2873     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_AND_2; break;
   2874     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_AND_4; break;
   2875     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_AND_8; break;
   2876     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_AND_16;break;
   2877     }
   2878     break;
   2879   case ISD::ATOMIC_LOAD_OR:
   2880     switch (VT.SimpleTy) {
   2881     default: llvm_unreachable("Unexpected value type for atomic!");
   2882     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_OR_1; break;
   2883     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_OR_2; break;
   2884     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_OR_4; break;
   2885     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_OR_8; break;
   2886     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_OR_16;break;
   2887     }
   2888     break;
   2889   case ISD::ATOMIC_LOAD_XOR:
   2890     switch (VT.SimpleTy) {
   2891     default: llvm_unreachable("Unexpected value type for atomic!");
   2892     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_XOR_1; break;
   2893     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_XOR_2; break;
   2894     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_XOR_4; break;
   2895     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_XOR_8; break;
   2896     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_XOR_16;break;
   2897     }
   2898     break;
   2899   case ISD::ATOMIC_LOAD_NAND:
   2900     switch (VT.SimpleTy) {
   2901     default: llvm_unreachable("Unexpected value type for atomic!");
   2902     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_NAND_1; break;
   2903     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_NAND_2; break;
   2904     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_NAND_4; break;
   2905     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_NAND_8; break;
   2906     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_NAND_16;break;
   2907     }
   2908     break;
   2909   case ISD::ATOMIC_LOAD_MAX:
   2910     switch (VT.SimpleTy) {
   2911     default: llvm_unreachable("Unexpected value type for atomic!");
   2912     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_MAX_1; break;
   2913     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_MAX_2; break;
   2914     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_MAX_4; break;
   2915     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_MAX_8; break;
   2916     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_MAX_16;break;
   2917     }
   2918     break;
   2919   case ISD::ATOMIC_LOAD_UMAX:
   2920     switch (VT.SimpleTy) {
   2921     default: llvm_unreachable("Unexpected value type for atomic!");
   2922     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_UMAX_1; break;
   2923     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_UMAX_2; break;
   2924     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_UMAX_4; break;
   2925     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_UMAX_8; break;
   2926     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_UMAX_16;break;
   2927     }
   2928     break;
   2929   case ISD::ATOMIC_LOAD_MIN:
   2930     switch (VT.SimpleTy) {
   2931     default: llvm_unreachable("Unexpected value type for atomic!");
   2932     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_MIN_1; break;
   2933     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_MIN_2; break;
   2934     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_MIN_4; break;
   2935     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_MIN_8; break;
   2936     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_MIN_16;break;
   2937     }
   2938     break;
   2939   case ISD::ATOMIC_LOAD_UMIN:
   2940     switch (VT.SimpleTy) {
   2941     default: llvm_unreachable("Unexpected value type for atomic!");
   2942     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_UMIN_1; break;
   2943     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_UMIN_2; break;
   2944     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_UMIN_4; break;
   2945     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_UMIN_8; break;
   2946     case MVT::i128:LC = RTLIB::SYNC_FETCH_AND_UMIN_16;break;
   2947     }
   2948     break;
   2949   }
   2950 
   2951   return ExpandChainLibCall(LC, Node, false);
   2952 }
   2953 
   2954 void SelectionDAGLegalize::ExpandNode(SDNode *Node) {
   2955   SmallVector<SDValue, 8> Results;
   2956   SDLoc dl(Node);
   2957   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
   2958   bool NeedInvert;
   2959   switch (Node->getOpcode()) {
   2960   case ISD::CTPOP:
   2961   case ISD::CTLZ:
   2962   case ISD::CTLZ_ZERO_UNDEF:
   2963   case ISD::CTTZ:
   2964   case ISD::CTTZ_ZERO_UNDEF:
   2965     Tmp1 = ExpandBitCount(Node->getOpcode(), Node->getOperand(0), dl);
   2966     Results.push_back(Tmp1);
   2967     break;
   2968   case ISD::BSWAP:
   2969     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
   2970     break;
   2971   case ISD::FRAMEADDR:
   2972   case ISD::RETURNADDR:
   2973   case ISD::FRAME_TO_ARGS_OFFSET:
   2974     Results.push_back(DAG.getConstant(0, Node->getValueType(0)));
   2975     break;
   2976   case ISD::FLT_ROUNDS_:
   2977     Results.push_back(DAG.getConstant(1, Node->getValueType(0)));
   2978     break;
   2979   case ISD::EH_RETURN:
   2980   case ISD::EH_LABEL:
   2981   case ISD::PREFETCH:
   2982   case ISD::VAEND:
   2983   case ISD::EH_SJLJ_LONGJMP:
   2984     // If the target didn't expand these, there's nothing to do, so just
   2985     // preserve the chain and be done.
   2986     Results.push_back(Node->getOperand(0));
   2987     break;
   2988   case ISD::EH_SJLJ_SETJMP:
   2989     // If the target didn't expand this, just return 'zero' and preserve the
   2990     // chain.
   2991     Results.push_back(DAG.getConstant(0, MVT::i32));
   2992     Results.push_back(Node->getOperand(0));
   2993     break;
   2994   case ISD::ATOMIC_FENCE: {
   2995     // If the target didn't lower this, lower it to '__sync_synchronize()' call
   2996     // FIXME: handle "fence singlethread" more efficiently.
   2997     TargetLowering::ArgListTy Args;
   2998 
   2999     TargetLowering::CallLoweringInfo CLI(DAG);
   3000     CLI.setDebugLoc(dl).setChain(Node->getOperand(0))
   3001       .setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
   3002                  DAG.getExternalSymbol("__sync_synchronize",
   3003                  TLI.getPointerTy()), std::move(Args), 0);
   3004 
   3005     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
   3006 
   3007     Results.push_back(CallResult.second);
   3008     break;
   3009   }
   3010   case ISD::ATOMIC_LOAD: {
   3011     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
   3012     SDValue Zero = DAG.getConstant(0, Node->getValueType(0));
   3013     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
   3014     SDValue Swap = DAG.getAtomicCmpSwap(
   3015         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
   3016         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
   3017         cast<AtomicSDNode>(Node)->getMemOperand(),
   3018         cast<AtomicSDNode>(Node)->getOrdering(),
   3019         cast<AtomicSDNode>(Node)->getOrdering(),
   3020         cast<AtomicSDNode>(Node)->getSynchScope());
   3021     Results.push_back(Swap.getValue(0));
   3022     Results.push_back(Swap.getValue(1));
   3023     break;
   3024   }
   3025   case ISD::ATOMIC_STORE: {
   3026     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
   3027     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
   3028                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
   3029                                  Node->getOperand(0),
   3030                                  Node->getOperand(1), Node->getOperand(2),
   3031                                  cast<AtomicSDNode>(Node)->getMemOperand(),
   3032                                  cast<AtomicSDNode>(Node)->getOrdering(),
   3033                                  cast<AtomicSDNode>(Node)->getSynchScope());
   3034     Results.push_back(Swap.getValue(1));
   3035     break;
   3036   }
   3037   // By default, atomic intrinsics are marked Legal and lowered. Targets
   3038   // which don't support them directly, however, may want libcalls, in which
   3039   // case they mark them Expand, and we get here.
   3040   case ISD::ATOMIC_SWAP:
   3041   case ISD::ATOMIC_LOAD_ADD:
   3042   case ISD::ATOMIC_LOAD_SUB:
   3043   case ISD::ATOMIC_LOAD_AND:
   3044   case ISD::ATOMIC_LOAD_OR:
   3045   case ISD::ATOMIC_LOAD_XOR:
   3046   case ISD::ATOMIC_LOAD_NAND:
   3047   case ISD::ATOMIC_LOAD_MIN:
   3048   case ISD::ATOMIC_LOAD_MAX:
   3049   case ISD::ATOMIC_LOAD_UMIN:
   3050   case ISD::ATOMIC_LOAD_UMAX:
   3051   case ISD::ATOMIC_CMP_SWAP: {
   3052     std::pair<SDValue, SDValue> Tmp = ExpandAtomic(Node);
   3053     Results.push_back(Tmp.first);
   3054     Results.push_back(Tmp.second);
   3055     break;
   3056   }
   3057   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
   3058     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
   3059     // splits out the success value as a comparison. Expanding the resulting
   3060     // ATOMIC_CMP_SWAP will produce a libcall.
   3061     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
   3062     SDValue Res = DAG.getAtomicCmpSwap(
   3063         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
   3064         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
   3065         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand(),
   3066         cast<AtomicSDNode>(Node)->getSuccessOrdering(),
   3067         cast<AtomicSDNode>(Node)->getFailureOrdering(),
   3068         cast<AtomicSDNode>(Node)->getSynchScope());
   3069 
   3070     SDValue Success = DAG.getSetCC(SDLoc(Node), Node->getValueType(1),
   3071                                    Res, Node->getOperand(2), ISD::SETEQ);
   3072 
   3073     Results.push_back(Res.getValue(0));
   3074     Results.push_back(Success);
   3075     Results.push_back(Res.getValue(1));
   3076     break;
   3077   }
   3078   case ISD::DYNAMIC_STACKALLOC:
   3079     ExpandDYNAMIC_STACKALLOC(Node, Results);
   3080     break;
   3081   case ISD::MERGE_VALUES:
   3082     for (unsigned i = 0; i < Node->getNumValues(); i++)
   3083       Results.push_back(Node->getOperand(i));
   3084     break;
   3085   case ISD::UNDEF: {
   3086     EVT VT = Node->getValueType(0);
   3087     if (VT.isInteger())
   3088       Results.push_back(DAG.getConstant(0, VT));
   3089     else {
   3090       assert(VT.isFloatingPoint() && "Unknown value type!");
   3091       Results.push_back(DAG.getConstantFP(0, VT));
   3092     }
   3093     break;
   3094   }
   3095   case ISD::TRAP: {
   3096     // If this operation is not supported, lower it to 'abort()' call
   3097     TargetLowering::ArgListTy Args;
   3098     TargetLowering::CallLoweringInfo CLI(DAG);
   3099     CLI.setDebugLoc(dl).setChain(Node->getOperand(0))
   3100       .setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
   3101                  DAG.getExternalSymbol("abort", TLI.getPointerTy()),
   3102                  std::move(Args), 0);
   3103     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
   3104 
   3105     Results.push_back(CallResult.second);
   3106     break;
   3107   }
   3108   case ISD::FP_ROUND:
   3109   case ISD::BITCAST:
   3110     Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
   3111                             Node->getValueType(0), dl);
   3112     Results.push_back(Tmp1);
   3113     break;
   3114   case ISD::FP_EXTEND:
   3115     Tmp1 = EmitStackConvert(Node->getOperand(0),
   3116                             Node->getOperand(0).getValueType(),
   3117                             Node->getValueType(0), dl);
   3118     Results.push_back(Tmp1);
   3119     break;
   3120   case ISD::SIGN_EXTEND_INREG: {
   3121     // NOTE: we could fall back on load/store here too for targets without
   3122     // SAR.  However, it is doubtful that any exist.
   3123     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
   3124     EVT VT = Node->getValueType(0);
   3125     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT);
   3126     if (VT.isVector())
   3127       ShiftAmountTy = VT;
   3128     unsigned BitsDiff = VT.getScalarType().getSizeInBits() -
   3129                         ExtraVT.getScalarType().getSizeInBits();
   3130     SDValue ShiftCst = DAG.getConstant(BitsDiff, ShiftAmountTy);
   3131     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
   3132                        Node->getOperand(0), ShiftCst);
   3133     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
   3134     Results.push_back(Tmp1);
   3135     break;
   3136   }
   3137   case ISD::FP_ROUND_INREG: {
   3138     // The only way we can lower this is to turn it into a TRUNCSTORE,
   3139     // EXTLOAD pair, targeting a temporary location (a stack slot).
   3140 
   3141     // NOTE: there is a choice here between constantly creating new stack
   3142     // slots and always reusing the same one.  We currently always create
   3143     // new ones, as reuse may inhibit scheduling.
   3144     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
   3145     Tmp1 = EmitStackConvert(Node->getOperand(0), ExtraVT,
   3146                             Node->getValueType(0), dl);
   3147     Results.push_back(Tmp1);
   3148     break;
   3149   }
   3150   case ISD::SINT_TO_FP:
   3151   case ISD::UINT_TO_FP:
   3152     Tmp1 = ExpandLegalINT_TO_FP(Node->getOpcode() == ISD::SINT_TO_FP,
   3153                                 Node->getOperand(0), Node->getValueType(0), dl);
   3154     Results.push_back(Tmp1);
   3155     break;
   3156   case ISD::FP_TO_SINT: {
   3157     EVT VT = Node->getOperand(0).getValueType();
   3158     EVT NVT = Node->getValueType(0);
   3159 
   3160     // FIXME: Only f32 to i64 conversions are supported.
   3161     if (VT != MVT::f32 || NVT != MVT::i64)
   3162       break;
   3163 
   3164     // Expand f32 -> i64 conversion
   3165     // This algorithm comes from compiler-rt's implementation of fixsfdi:
   3166     // https://github.com/llvm-mirror/compiler-rt/blob/master/lib/builtins/fixsfdi.c
   3167     EVT IntVT = EVT::getIntegerVT(*DAG.getContext(),
   3168                                   VT.getSizeInBits());
   3169     SDValue ExponentMask = DAG.getConstant(0x7F800000, IntVT);
   3170     SDValue ExponentLoBit = DAG.getConstant(23, IntVT);
   3171     SDValue Bias = DAG.getConstant(127, IntVT);
   3172     SDValue SignMask = DAG.getConstant(APInt::getSignBit(VT.getSizeInBits()),
   3173                                        IntVT);
   3174     SDValue SignLowBit = DAG.getConstant(VT.getSizeInBits() - 1, IntVT);
   3175     SDValue MantissaMask = DAG.getConstant(0x007FFFFF, IntVT);
   3176 
   3177     SDValue Bits = DAG.getNode(ISD::BITCAST, dl, IntVT, Node->getOperand(0));
   3178 
   3179     SDValue ExponentBits = DAG.getNode(ISD::SRL, dl, IntVT,
   3180         DAG.getNode(ISD::AND, dl, IntVT, Bits, ExponentMask),
   3181         DAG.getZExtOrTrunc(ExponentLoBit, dl, TLI.getShiftAmountTy(IntVT)));
   3182     SDValue Exponent = DAG.getNode(ISD::SUB, dl, IntVT, ExponentBits, Bias);
   3183 
   3184     SDValue Sign = DAG.getNode(ISD::SRA, dl, IntVT,
   3185         DAG.getNode(ISD::AND, dl, IntVT, Bits, SignMask),
   3186         DAG.getZExtOrTrunc(SignLowBit, dl, TLI.getShiftAmountTy(IntVT)));
   3187     Sign = DAG.getSExtOrTrunc(Sign, dl, NVT);
   3188 
   3189     SDValue R = DAG.getNode(ISD::OR, dl, IntVT,
   3190         DAG.getNode(ISD::AND, dl, IntVT, Bits, MantissaMask),
   3191         DAG.getConstant(0x00800000, IntVT));
   3192 
   3193     R = DAG.getZExtOrTrunc(R, dl, NVT);
   3194 
   3195 
   3196     R = DAG.getSelectCC(dl, Exponent, ExponentLoBit,
   3197        DAG.getNode(ISD::SHL, dl, NVT, R,
   3198                    DAG.getZExtOrTrunc(
   3199                       DAG.getNode(ISD::SUB, dl, IntVT, Exponent, ExponentLoBit),
   3200                       dl, TLI.getShiftAmountTy(IntVT))),
   3201        DAG.getNode(ISD::SRL, dl, NVT, R,
   3202                    DAG.getZExtOrTrunc(
   3203                       DAG.getNode(ISD::SUB, dl, IntVT, ExponentLoBit, Exponent),
   3204                       dl, TLI.getShiftAmountTy(IntVT))),
   3205        ISD::SETGT);
   3206 
   3207     SDValue Ret = DAG.getNode(ISD::SUB, dl, NVT,
   3208         DAG.getNode(ISD::XOR, dl, NVT, R, Sign),
   3209         Sign);
   3210 
   3211     Results.push_back(DAG.getSelectCC(dl, Exponent, DAG.getConstant(0, IntVT),
   3212         DAG.getConstant(0, NVT), Ret, ISD::SETLT));
   3213     break;
   3214   }
   3215   case ISD::FP_TO_UINT: {
   3216     SDValue True, False;
   3217     EVT VT =  Node->getOperand(0).getValueType();
   3218     EVT NVT = Node->getValueType(0);
   3219     APFloat apf(DAG.EVTToAPFloatSemantics(VT),
   3220                 APInt::getNullValue(VT.getSizeInBits()));
   3221     APInt x = APInt::getSignBit(NVT.getSizeInBits());
   3222     (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
   3223     Tmp1 = DAG.getConstantFP(apf, VT);
   3224     Tmp2 = DAG.getSetCC(dl, getSetCCResultType(VT),
   3225                         Node->getOperand(0),
   3226                         Tmp1, ISD::SETLT);
   3227     True = DAG.getNode(ISD::FP_TO_SINT, dl, NVT, Node->getOperand(0));
   3228     False = DAG.getNode(ISD::FP_TO_SINT, dl, NVT,
   3229                         DAG.getNode(ISD::FSUB, dl, VT,
   3230                                     Node->getOperand(0), Tmp1));
   3231     False = DAG.getNode(ISD::XOR, dl, NVT, False,
   3232                         DAG.getConstant(x, NVT));
   3233     Tmp1 = DAG.getSelect(dl, NVT, Tmp2, True, False);
   3234     Results.push_back(Tmp1);
   3235     break;
   3236   }
   3237   case ISD::VAARG: {
   3238     const Value *V = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
   3239     EVT VT = Node->getValueType(0);
   3240     Tmp1 = Node->getOperand(0);
   3241     Tmp2 = Node->getOperand(1);
   3242     unsigned Align = Node->getConstantOperandVal(3);
   3243 
   3244     SDValue VAListLoad = DAG.getLoad(TLI.getPointerTy(), dl, Tmp1, Tmp2,
   3245                                      MachinePointerInfo(V),
   3246                                      false, false, false, 0);
   3247     SDValue VAList = VAListLoad;
   3248 
   3249     if (Align > TLI.getMinStackArgumentAlignment()) {
   3250       assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2");
   3251 
   3252       VAList = DAG.getNode(ISD::ADD, dl, VAList.getValueType(), VAList,
   3253                            DAG.getConstant(Align - 1,
   3254                                            VAList.getValueType()));
   3255 
   3256       VAList = DAG.getNode(ISD::AND, dl, VAList.getValueType(), VAList,
   3257                            DAG.getConstant(-(int64_t)Align,
   3258                                            VAList.getValueType()));
   3259     }
   3260 
   3261     // Increment the pointer, VAList, to the next vaarg
   3262     Tmp3 = DAG.getNode(ISD::ADD, dl, VAList.getValueType(), VAList,
   3263                        DAG.getConstant(TLI.getDataLayout()->
   3264                           getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext())),
   3265                                        VAList.getValueType()));
   3266     // Store the incremented VAList to the legalized pointer
   3267     Tmp3 = DAG.getStore(VAListLoad.getValue(1), dl, Tmp3, Tmp2,
   3268                         MachinePointerInfo(V), false, false, 0);
   3269     // Load the actual argument out of the pointer VAList
   3270     Results.push_back(DAG.getLoad(VT, dl, Tmp3, VAList, MachinePointerInfo(),
   3271                                   false, false, false, 0));
   3272     Results.push_back(Results[0].getValue(1));
   3273     break;
   3274   }
   3275   case ISD::VACOPY: {
   3276     // This defaults to loading a pointer from the input and storing it to the
   3277     // output, returning the chain.
   3278     const Value *VD = cast<SrcValueSDNode>(Node->getOperand(3))->getValue();
   3279     const Value *VS = cast<SrcValueSDNode>(Node->getOperand(4))->getValue();
   3280     Tmp1 = DAG.getLoad(TLI.getPointerTy(), dl, Node->getOperand(0),
   3281                        Node->getOperand(2), MachinePointerInfo(VS),
   3282                        false, false, false, 0);
   3283     Tmp1 = DAG.getStore(Tmp1.getValue(1), dl, Tmp1, Node->getOperand(1),
   3284                         MachinePointerInfo(VD), false, false, 0);
   3285     Results.push_back(Tmp1);
   3286     break;
   3287   }
   3288   case ISD::EXTRACT_VECTOR_ELT:
   3289     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
   3290       // This must be an access of the only element.  Return it.
   3291       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
   3292                          Node->getOperand(0));
   3293     else
   3294       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
   3295     Results.push_back(Tmp1);
   3296     break;
   3297   case ISD::EXTRACT_SUBVECTOR:
   3298     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
   3299     break;
   3300   case ISD::INSERT_SUBVECTOR:
   3301     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
   3302     break;
   3303   case ISD::CONCAT_VECTORS: {
   3304     Results.push_back(ExpandVectorBuildThroughStack(Node));
   3305     break;
   3306   }
   3307   case ISD::SCALAR_TO_VECTOR:
   3308     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
   3309     break;
   3310   case ISD::INSERT_VECTOR_ELT:
   3311     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
   3312                                               Node->getOperand(1),
   3313                                               Node->getOperand(2), dl));
   3314     break;
   3315   case ISD::VECTOR_SHUFFLE: {
   3316     SmallVector<int, 32> NewMask;
   3317     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
   3318 
   3319     EVT VT = Node->getValueType(0);
   3320     EVT EltVT = VT.getVectorElementType();
   3321     SDValue Op0 = Node->getOperand(0);
   3322     SDValue Op1 = Node->getOperand(1);
   3323     if (!TLI.isTypeLegal(EltVT)) {
   3324 
   3325       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
   3326 
   3327       // BUILD_VECTOR operands are allowed to be wider than the element type.
   3328       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
   3329       // it.
   3330       if (NewEltVT.bitsLT(EltVT)) {
   3331 
   3332         // Convert shuffle node.
   3333         // If original node was v4i64 and the new EltVT is i32,
   3334         // cast operands to v8i32 and re-build the mask.
   3335 
   3336         // Calculate new VT, the size of the new VT should be equal to original.
   3337         EVT NewVT =
   3338             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
   3339                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
   3340         assert(NewVT.bitsEq(VT));
   3341 
   3342         // cast operands to new VT
   3343         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
   3344         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
   3345 
   3346         // Convert the shuffle mask
   3347         unsigned int factor =
   3348                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
   3349 
   3350         // EltVT gets smaller
   3351         assert(factor > 0);
   3352 
   3353         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
   3354           if (Mask[i] < 0) {
   3355             for (unsigned fi = 0; fi < factor; ++fi)
   3356               NewMask.push_back(Mask[i]);
   3357           }
   3358           else {
   3359             for (unsigned fi = 0; fi < factor; ++fi)
   3360               NewMask.push_back(Mask[i]*factor+fi);
   3361           }
   3362         }
   3363         Mask = NewMask;
   3364         VT = NewVT;
   3365       }
   3366       EltVT = NewEltVT;
   3367     }
   3368     unsigned NumElems = VT.getVectorNumElements();
   3369     SmallVector<SDValue, 16> Ops;
   3370     for (unsigned i = 0; i != NumElems; ++i) {
   3371       if (Mask[i] < 0) {
   3372         Ops.push_back(DAG.getUNDEF(EltVT));
   3373         continue;
   3374       }
   3375       unsigned Idx = Mask[i];
   3376       if (Idx < NumElems)
   3377         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
   3378                                   Op0,
   3379                                   DAG.getConstant(Idx, TLI.getVectorIdxTy())));
   3380       else
   3381         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
   3382                                   Op1,
   3383                                   DAG.getConstant(Idx - NumElems,
   3384                                                   TLI.getVectorIdxTy())));
   3385     }
   3386 
   3387     Tmp1 = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
   3388     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
   3389     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
   3390     Results.push_back(Tmp1);
   3391     break;
   3392   }
   3393   case ISD::EXTRACT_ELEMENT: {
   3394     EVT OpTy = Node->getOperand(0).getValueType();
   3395     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
   3396       // 1 -> Hi
   3397       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
   3398                          DAG.getConstant(OpTy.getSizeInBits()/2,
   3399                     TLI.getShiftAmountTy(Node->getOperand(0).getValueType())));
   3400       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
   3401     } else {
   3402       // 0 -> Lo
   3403       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
   3404                          Node->getOperand(0));
   3405     }
   3406     Results.push_back(Tmp1);
   3407     break;
   3408   }
   3409   case ISD::STACKSAVE:
   3410     // Expand to CopyFromReg if the target set
   3411     // StackPointerRegisterToSaveRestore.
   3412     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
   3413       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
   3414                                            Node->getValueType(0)));
   3415       Results.push_back(Results[0].getValue(1));
   3416     } else {
   3417       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
   3418       Results.push_back(Node->getOperand(0));
   3419     }
   3420     break;
   3421   case ISD::STACKRESTORE:
   3422     // Expand to CopyToReg if the target set
   3423     // StackPointerRegisterToSaveRestore.
   3424     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
   3425       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
   3426                                          Node->getOperand(1)));
   3427     } else {
   3428       Results.push_back(Node->getOperand(0));
   3429     }
   3430     break;
   3431   case ISD::FCOPYSIGN:
   3432     Results.push_back(ExpandFCOPYSIGN(Node));
   3433     break;
   3434   case ISD::FNEG:
   3435     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
   3436     Tmp1 = DAG.getConstantFP(-0.0, Node->getValueType(0));
   3437     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
   3438                        Node->getOperand(0));
   3439     Results.push_back(Tmp1);
   3440     break;
   3441   case ISD::FABS: {
   3442     // Expand Y = FABS(X) -> Y = (X >u 0.0) ? X : fneg(X).
   3443     EVT VT = Node->getValueType(0);
   3444     Tmp1 = Node->getOperand(0);
   3445     Tmp2 = DAG.getConstantFP(0.0, VT);
   3446     Tmp2 = DAG.getSetCC(dl, getSetCCResultType(Tmp1.getValueType()),
   3447                         Tmp1, Tmp2, ISD::SETUGT);
   3448     Tmp3 = DAG.getNode(ISD::FNEG, dl, VT, Tmp1);
   3449     Tmp1 = DAG.getSelect(dl, VT, Tmp2, Tmp1, Tmp3);
   3450     Results.push_back(Tmp1);
   3451     break;
   3452   }
   3453   case ISD::FSQRT:
   3454     Results.push_back(ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
   3455                                       RTLIB::SQRT_F80, RTLIB::SQRT_F128,
   3456                                       RTLIB::SQRT_PPCF128));
   3457     break;
   3458   case ISD::FSIN:
   3459   case ISD::FCOS: {
   3460     EVT VT = Node->getValueType(0);
   3461     bool isSIN = Node->getOpcode() == ISD::FSIN;
   3462     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
   3463     // fcos which share the same operand and both are used.
   3464     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
   3465          canCombineSinCosLibcall(Node, TLI, TM))
   3466         && useSinCos(Node)) {
   3467       SDVTList VTs = DAG.getVTList(VT, VT);
   3468       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
   3469       if (!isSIN)
   3470         Tmp1 = Tmp1.getValue(1);
   3471       Results.push_back(Tmp1);
   3472     } else if (isSIN) {
   3473       Results.push_back(ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
   3474                                         RTLIB::SIN_F80, RTLIB::SIN_F128,
   3475                                         RTLIB::SIN_PPCF128));
   3476     } else {
   3477       Results.push_back(ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
   3478                                         RTLIB::COS_F80, RTLIB::COS_F128,
   3479                                         RTLIB::COS_PPCF128));
   3480     }
   3481     break;
   3482   }
   3483   case ISD::FSINCOS:
   3484     // Expand into sincos libcall.
   3485     ExpandSinCosLibCall(Node, Results);
   3486     break;
   3487   case ISD::FLOG:
   3488     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
   3489                                       RTLIB::LOG_F80, RTLIB::LOG_F128,
   3490                                       RTLIB::LOG_PPCF128));
   3491     break;
   3492   case ISD::FLOG2:
   3493     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
   3494                                       RTLIB::LOG2_F80, RTLIB::LOG2_F128,
   3495                                       RTLIB::LOG2_PPCF128));
   3496     break;
   3497   case ISD::FLOG10:
   3498     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
   3499                                       RTLIB::LOG10_F80, RTLIB::LOG10_F128,
   3500                                       RTLIB::LOG10_PPCF128));
   3501     break;
   3502   case ISD::FEXP:
   3503     Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
   3504                                       RTLIB::EXP_F80, RTLIB::EXP_F128,
   3505                                       RTLIB::EXP_PPCF128));
   3506     break;
   3507   case ISD::FEXP2:
   3508     Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
   3509                                       RTLIB::EXP2_F80, RTLIB::EXP2_F128,
   3510                                       RTLIB::EXP2_PPCF128));
   3511     break;
   3512   case ISD::FTRUNC:
   3513     Results.push_back(ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
   3514                                       RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
   3515                                       RTLIB::TRUNC_PPCF128));
   3516     break;
   3517   case ISD::FFLOOR:
   3518     Results.push_back(ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
   3519                                       RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
   3520                                       RTLIB::FLOOR_PPCF128));
   3521     break;
   3522   case ISD::FCEIL:
   3523     Results.push_back(ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
   3524                                       RTLIB::CEIL_F80, RTLIB::CEIL_F128,
   3525                                       RTLIB::CEIL_PPCF128));
   3526     break;
   3527   case ISD::FRINT:
   3528     Results.push_back(ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
   3529                                       RTLIB::RINT_F80, RTLIB::RINT_F128,
   3530                                       RTLIB::RINT_PPCF128));
   3531     break;
   3532   case ISD::FNEARBYINT:
   3533     Results.push_back(ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
   3534                                       RTLIB::NEARBYINT_F64,
   3535                                       RTLIB::NEARBYINT_F80,
   3536                                       RTLIB::NEARBYINT_F128,
   3537                                       RTLIB::NEARBYINT_PPCF128));
   3538     break;
   3539   case ISD::FROUND:
   3540     Results.push_back(ExpandFPLibCall(Node, RTLIB::ROUND_F32,
   3541                                       RTLIB::ROUND_F64,
   3542                                       RTLIB::ROUND_F80,
   3543                                       RTLIB::ROUND_F128,
   3544                                       RTLIB::ROUND_PPCF128));
   3545     break;
   3546   case ISD::FPOWI:
   3547     Results.push_back(ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
   3548                                       RTLIB::POWI_F80, RTLIB::POWI_F128,
   3549                                       RTLIB::POWI_PPCF128));
   3550     break;
   3551   case ISD::FPOW:
   3552     Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
   3553                                       RTLIB::POW_F80, RTLIB::POW_F128,
   3554                                       RTLIB::POW_PPCF128));
   3555     break;
   3556   case ISD::FDIV:
   3557     Results.push_back(ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
   3558                                       RTLIB::DIV_F80, RTLIB::DIV_F128,
   3559                                       RTLIB::DIV_PPCF128));
   3560     break;
   3561   case ISD::FREM:
   3562     Results.push_back(ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
   3563                                       RTLIB::REM_F80, RTLIB::REM_F128,
   3564                                       RTLIB::REM_PPCF128));
   3565     break;
   3566   case ISD::FMA:
   3567     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
   3568                                       RTLIB::FMA_F80, RTLIB::FMA_F128,
   3569                                       RTLIB::FMA_PPCF128));
   3570     break;
   3571   case ISD::FP16_TO_FP32:
   3572     Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
   3573     break;
   3574   case ISD::FP32_TO_FP16:
   3575     Results.push_back(ExpandLibCall(RTLIB::FPROUND_F32_F16, Node, false));
   3576     break;
   3577   case ISD::ConstantFP: {
   3578     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
   3579     // Check to see if this FP immediate is already legal.
   3580     // If this is a legal constant, turn it into a TargetConstantFP node.
   3581     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0)))
   3582       Results.push_back(ExpandConstantFP(CFP, true));
   3583     break;
   3584   }
   3585   case ISD::FSUB: {
   3586     EVT VT = Node->getValueType(0);
   3587     assert(TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
   3588            TLI.isOperationLegalOrCustom(ISD::FNEG, VT) &&
   3589            "Don't know how to expand this FP subtraction!");
   3590     Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
   3591     Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1);
   3592     Results.push_back(Tmp1);
   3593     break;
   3594   }
   3595   case ISD::SUB: {
   3596     EVT VT = Node->getValueType(0);
   3597     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
   3598            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
   3599            "Don't know how to expand this subtraction!");
   3600     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
   3601                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), VT));
   3602     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, VT));
   3603     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
   3604     break;
   3605   }
   3606   case ISD::UREM:
   3607   case ISD::SREM: {
   3608     EVT VT = Node->getValueType(0);
   3609     bool isSigned = Node->getOpcode() == ISD::SREM;
   3610     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
   3611     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
   3612     Tmp2 = Node->getOperand(0);
   3613     Tmp3 = Node->getOperand(1);
   3614     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT) ||
   3615         (isDivRemLibcallAvailable(Node, isSigned, TLI) &&
   3616          // If div is legal, it's better to do the normal expansion
   3617          !TLI.isOperationLegalOrCustom(DivOpc, Node->getValueType(0)) &&
   3618          useDivRem(Node, isSigned, false))) {
   3619       SDVTList VTs = DAG.getVTList(VT, VT);
   3620       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
   3621     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
   3622       // X % Y -> X-X/Y*Y
   3623       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
   3624       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
   3625       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
   3626     } else if (isSigned)
   3627       Tmp1 = ExpandIntLibCall(Node, true,
   3628                               RTLIB::SREM_I8,
   3629                               RTLIB::SREM_I16, RTLIB::SREM_I32,
   3630                               RTLIB::SREM_I64, RTLIB::SREM_I128);
   3631     else
   3632       Tmp1 = ExpandIntLibCall(Node, false,
   3633                               RTLIB::UREM_I8,
   3634                               RTLIB::UREM_I16, RTLIB::UREM_I32,
   3635                               RTLIB::UREM_I64, RTLIB::UREM_I128);
   3636     Results.push_back(Tmp1);
   3637     break;
   3638   }
   3639   case ISD::UDIV:
   3640   case ISD::SDIV: {
   3641     bool isSigned = Node->getOpcode() == ISD::SDIV;
   3642     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
   3643     EVT VT = Node->getValueType(0);
   3644     SDVTList VTs = DAG.getVTList(VT, VT);
   3645     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT) ||
   3646         (isDivRemLibcallAvailable(Node, isSigned, TLI) &&
   3647          useDivRem(Node, isSigned, true)))
   3648       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
   3649                          Node->getOperand(1));
   3650     else if (isSigned)
   3651       Tmp1 = ExpandIntLibCall(Node, true,
   3652                               RTLIB::SDIV_I8,
   3653                               RTLIB::SDIV_I16, RTLIB::SDIV_I32,
   3654                               RTLIB::SDIV_I64, RTLIB::SDIV_I128);
   3655     else
   3656       Tmp1 = ExpandIntLibCall(Node, false,
   3657                               RTLIB::UDIV_I8,
   3658                               RTLIB::UDIV_I16, RTLIB::UDIV_I32,
   3659                               RTLIB::UDIV_I64, RTLIB::UDIV_I128);
   3660     Results.push_back(Tmp1);
   3661     break;
   3662   }
   3663   case ISD::MULHU:
   3664   case ISD::MULHS: {
   3665     unsigned ExpandOpcode = Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI :
   3666                                                               ISD::SMUL_LOHI;
   3667     EVT VT = Node->getValueType(0);
   3668     SDVTList VTs = DAG.getVTList(VT, VT);
   3669     assert(TLI.isOperationLegalOrCustom(ExpandOpcode, VT) &&
   3670            "If this wasn't legal, it shouldn't have been created!");
   3671     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
   3672                        Node->getOperand(1));
   3673     Results.push_back(Tmp1.getValue(1));
   3674     break;
   3675   }
   3676   case ISD::SDIVREM:
   3677   case ISD::UDIVREM:
   3678     // Expand into divrem libcall
   3679     ExpandDivRemLibCall(Node, Results);
   3680     break;
   3681   case ISD::MUL: {
   3682     EVT VT = Node->getValueType(0);
   3683     SDVTList VTs = DAG.getVTList(VT, VT);
   3684     // See if multiply or divide can be lowered using two-result operations.
   3685     // We just need the low half of the multiply; try both the signed
   3686     // and unsigned forms. If the target supports both SMUL_LOHI and
   3687     // UMUL_LOHI, form a preference by checking which forms of plain
   3688     // MULH it supports.
   3689     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
   3690     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
   3691     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
   3692     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
   3693     unsigned OpToUse = 0;
   3694     if (HasSMUL_LOHI && !HasMULHS) {
   3695       OpToUse = ISD::SMUL_LOHI;
   3696     } else if (HasUMUL_LOHI && !HasMULHU) {
   3697       OpToUse = ISD::UMUL_LOHI;
   3698     } else if (HasSMUL_LOHI) {
   3699       OpToUse = ISD::SMUL_LOHI;
   3700     } else if (HasUMUL_LOHI) {
   3701       OpToUse = ISD::UMUL_LOHI;
   3702     }
   3703     if (OpToUse) {
   3704       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
   3705                                     Node->getOperand(1)));
   3706       break;
   3707     }
   3708 
   3709     SDValue Lo, Hi;
   3710     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
   3711     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
   3712         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
   3713         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
   3714         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
   3715         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG)) {
   3716       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
   3717       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
   3718       SDValue Shift = DAG.getConstant(HalfType.getSizeInBits(),
   3719                                       TLI.getShiftAmountTy(HalfType));
   3720       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
   3721       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
   3722       break;
   3723     }
   3724 
   3725     Tmp1 = ExpandIntLibCall(Node, false,
   3726                             RTLIB::MUL_I8,
   3727                             RTLIB::MUL_I16, RTLIB::MUL_I32,
   3728                             RTLIB::MUL_I64, RTLIB::MUL_I128);
   3729     Results.push_back(Tmp1);
   3730     break;
   3731   }
   3732   case ISD::SADDO:
   3733   case ISD::SSUBO: {
   3734     SDValue LHS = Node->getOperand(0);
   3735     SDValue RHS = Node->getOperand(1);
   3736     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::SADDO ?
   3737                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
   3738                               LHS, RHS);
   3739     Results.push_back(Sum);
   3740     EVT ResultType = Node->getValueType(1);
   3741     EVT OType = getSetCCResultType(Node->getValueType(0));
   3742 
   3743     SDValue Zero = DAG.getConstant(0, LHS.getValueType());
   3744 
   3745     //   LHSSign -> LHS >= 0
   3746     //   RHSSign -> RHS >= 0
   3747     //   SumSign -> Sum >= 0
   3748     //
   3749     //   Add:
   3750     //   Overflow -> (LHSSign == RHSSign) && (LHSSign != SumSign)
   3751     //   Sub:
   3752     //   Overflow -> (LHSSign != RHSSign) && (LHSSign != SumSign)
   3753     //
   3754     SDValue LHSSign = DAG.getSetCC(dl, OType, LHS, Zero, ISD::SETGE);
   3755     SDValue RHSSign = DAG.getSetCC(dl, OType, RHS, Zero, ISD::SETGE);
   3756     SDValue SignsMatch = DAG.getSetCC(dl, OType, LHSSign, RHSSign,
   3757                                       Node->getOpcode() == ISD::SADDO ?
   3758                                       ISD::SETEQ : ISD::SETNE);
   3759 
   3760     SDValue SumSign = DAG.getSetCC(dl, OType, Sum, Zero, ISD::SETGE);
   3761     SDValue SumSignNE = DAG.getSetCC(dl, OType, LHSSign, SumSign, ISD::SETNE);
   3762 
   3763     SDValue Cmp = DAG.getNode(ISD::AND, dl, OType, SignsMatch, SumSignNE);
   3764     Results.push_back(DAG.getBoolExtOrTrunc(Cmp, dl, ResultType, ResultType));
   3765     break;
   3766   }
   3767   case ISD::UADDO:
   3768   case ISD::USUBO: {
   3769     SDValue LHS = Node->getOperand(0);
   3770     SDValue RHS = Node->getOperand(1);
   3771     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::UADDO ?
   3772                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
   3773                               LHS, RHS);
   3774     Results.push_back(Sum);
   3775 
   3776     EVT ResultType = Node->getValueType(1);
   3777     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
   3778     ISD::CondCode CC
   3779       = Node->getOpcode() == ISD::UADDO ? ISD::SETULT : ISD::SETUGT;
   3780     SDValue SetCC = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
   3781 
   3782     Results.push_back(DAG.getBoolExtOrTrunc(SetCC, dl, ResultType, ResultType));
   3783     break;
   3784   }
   3785   case ISD::UMULO:
   3786   case ISD::SMULO: {
   3787     EVT VT = Node->getValueType(0);
   3788     EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
   3789     SDValue LHS = Node->getOperand(0);
   3790     SDValue RHS = Node->getOperand(1);
   3791     SDValue BottomHalf;
   3792     SDValue TopHalf;
   3793     static const unsigned Ops[2][3] =
   3794         { { ISD::MULHU, ISD::UMUL_LOHI, ISD::ZERO_EXTEND },
   3795           { ISD::MULHS, ISD::SMUL_LOHI, ISD::SIGN_EXTEND }};
   3796     bool isSigned = Node->getOpcode() == ISD::SMULO;
   3797     if (TLI.isOperationLegalOrCustom(Ops[isSigned][0], VT)) {
   3798       BottomHalf = DAG.getNode(ISD::MUL, dl, VT, LHS, RHS);
   3799       TopHalf = DAG.getNode(Ops[isSigned][0], dl, VT, LHS, RHS);
   3800     } else if (TLI.isOperationLegalOrCustom(Ops[isSigned][1], VT)) {
   3801       BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
   3802                                RHS);
   3803       TopHalf = BottomHalf.getValue(1);
   3804     } else if (TLI.isTypeLegal(WideVT)) {
   3805       LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
   3806       RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
   3807       Tmp1 = DAG.getNode(ISD::MUL, dl, WideVT, LHS, RHS);
   3808       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
   3809                                DAG.getIntPtrConstant(0));
   3810       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
   3811                             DAG.getIntPtrConstant(1));
   3812     } else {
   3813       // We can fall back to a libcall with an illegal type for the MUL if we
   3814       // have a libcall big enough.
   3815       // Also, we can fall back to a division in some cases, but that's a big
   3816       // performance hit in the general case.
   3817       RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
   3818       if (WideVT == MVT::i16)
   3819         LC = RTLIB::MUL_I16;
   3820       else if (WideVT == MVT::i32)
   3821         LC = RTLIB::MUL_I32;
   3822       else if (WideVT == MVT::i64)
   3823         LC = RTLIB::MUL_I64;
   3824       else if (WideVT == MVT::i128)
   3825         LC = RTLIB::MUL_I128;
   3826       assert(LC != RTLIB::UNKNOWN_LIBCALL && "Cannot expand this operation!");
   3827 
   3828       // The high part is obtained by SRA'ing all but one of the bits of low
   3829       // part.
   3830       unsigned LoSize = VT.getSizeInBits();
   3831       SDValue HiLHS = DAG.getNode(ISD::SRA, dl, VT, RHS,
   3832                                 DAG.getConstant(LoSize-1, TLI.getPointerTy()));
   3833       SDValue HiRHS = DAG.getNode(ISD::SRA, dl, VT, LHS,
   3834                                 DAG.getConstant(LoSize-1, TLI.getPointerTy()));
   3835 
   3836       // Here we're passing the 2 arguments explicitly as 4 arguments that are
   3837       // pre-lowered to the correct types. This all depends upon WideVT not
   3838       // being a legal type for the architecture and thus has to be split to
   3839       // two arguments.
   3840       SDValue Args[] = { LHS, HiLHS, RHS, HiRHS };
   3841       SDValue Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
   3842       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Ret,
   3843                                DAG.getIntPtrConstant(0));
   3844       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Ret,
   3845                             DAG.getIntPtrConstant(1));
   3846       // Ret is a node with an illegal type. Because such things are not
   3847       // generally permitted during this phase of legalization, delete the
   3848       // node. The above EXTRACT_ELEMENT nodes should have been folded.
   3849       DAG.DeleteNode(Ret.getNode());
   3850     }
   3851 
   3852     if (isSigned) {
   3853       Tmp1 = DAG.getConstant(VT.getSizeInBits() - 1,
   3854                              TLI.getShiftAmountTy(BottomHalf.getValueType()));
   3855       Tmp1 = DAG.getNode(ISD::SRA, dl, VT, BottomHalf, Tmp1);
   3856       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf, Tmp1,
   3857                              ISD::SETNE);
   3858     } else {
   3859       TopHalf = DAG.getSetCC(dl, getSetCCResultType(VT), TopHalf,
   3860                              DAG.getConstant(0, VT), ISD::SETNE);
   3861     }
   3862     Results.push_back(BottomHalf);
   3863     Results.push_back(TopHalf);
   3864     break;
   3865   }
   3866   case ISD::BUILD_PAIR: {
   3867     EVT PairTy = Node->getValueType(0);
   3868     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
   3869     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
   3870     Tmp2 = DAG.getNode(ISD::SHL, dl, PairTy, Tmp2,
   3871                        DAG.getConstant(PairTy.getSizeInBits()/2,
   3872                                        TLI.getShiftAmountTy(PairTy)));
   3873     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
   3874     break;
   3875   }
   3876   case ISD::SELECT:
   3877     Tmp1 = Node->getOperand(0);
   3878     Tmp2 = Node->getOperand(1);
   3879     Tmp3 = Node->getOperand(2);
   3880     if (Tmp1.getOpcode() == ISD::SETCC) {
   3881       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
   3882                              Tmp2, Tmp3,
   3883                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
   3884     } else {
   3885       Tmp1 = DAG.getSelectCC(dl, Tmp1,
   3886                              DAG.getConstant(0, Tmp1.getValueType()),
   3887                              Tmp2, Tmp3, ISD::SETNE);
   3888     }
   3889     Results.push_back(Tmp1);
   3890     break;
   3891   case ISD::BR_JT: {
   3892     SDValue Chain = Node->getOperand(0);
   3893     SDValue Table = Node->getOperand(1);
   3894     SDValue Index = Node->getOperand(2);
   3895 
   3896     EVT PTy = TLI.getPointerTy();
   3897 
   3898     const DataLayout &TD = *TLI.getDataLayout();
   3899     unsigned EntrySize =
   3900       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
   3901 
   3902     Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(),
   3903                        Index, DAG.getConstant(EntrySize, Index.getValueType()));
   3904     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
   3905                                Index, Table);
   3906 
   3907     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
   3908     SDValue LD = DAG.getExtLoad(ISD::SEXTLOAD, dl, PTy, Chain, Addr,
   3909                                 MachinePointerInfo::getJumpTable(), MemVT,
   3910                                 false, false, 0);
   3911     Addr = LD;
   3912     if (TM.getRelocationModel() == Reloc::PIC_) {
   3913       // For PIC, the sequence is:
   3914       // BRIND(load(Jumptable + index) + RelocBase)
   3915       // RelocBase can be JumpTable, GOT or some sort of global base.
   3916       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
   3917                           TLI.getPICJumpTableRelocBase(Table, DAG));
   3918     }
   3919     Tmp1 = DAG.getNode(ISD::BRIND, dl, MVT::Other, LD.getValue(1), Addr);
   3920     Results.push_back(Tmp1);
   3921     break;
   3922   }
   3923   case ISD::BRCOND:
   3924     // Expand brcond's setcc into its constituent parts and create a BR_CC
   3925     // Node.
   3926     Tmp1 = Node->getOperand(0);
   3927     Tmp2 = Node->getOperand(1);
   3928     if (Tmp2.getOpcode() == ISD::SETCC) {
   3929       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
   3930                          Tmp1, Tmp2.getOperand(2),
   3931                          Tmp2.getOperand(0), Tmp2.getOperand(1),
   3932                          Node->getOperand(2));
   3933     } else {
   3934       // We test only the i1 bit.  Skip the AND if UNDEF.
   3935       Tmp3 = (Tmp2.getOpcode() == ISD::UNDEF) ? Tmp2 :
   3936         DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
   3937                     DAG.getConstant(1, Tmp2.getValueType()));
   3938       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
   3939                          DAG.getCondCode(ISD::SETNE), Tmp3,
   3940                          DAG.getConstant(0, Tmp3.getValueType()),
   3941                          Node->getOperand(2));
   3942     }
   3943     Results.push_back(Tmp1);
   3944     break;
   3945   case ISD::SETCC: {
   3946     Tmp1 = Node->getOperand(0);
   3947     Tmp2 = Node->getOperand(1);
   3948     Tmp3 = Node->getOperand(2);
   3949     bool Legalized = LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2,
   3950                                            Tmp3, NeedInvert, dl);
   3951 
   3952     if (Legalized) {
   3953       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
   3954       // condition code, create a new SETCC node.
   3955       if (Tmp3.getNode())
   3956         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
   3957                            Tmp1, Tmp2, Tmp3);
   3958 
   3959       // If we expanded the SETCC by inverting the condition code, then wrap
   3960       // the existing SETCC in a NOT to restore the intended condition.
   3961       if (NeedInvert)
   3962         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
   3963 
   3964       Results.push_back(Tmp1);
   3965       break;
   3966     }
   3967 
   3968     // Otherwise, SETCC for the given comparison type must be completely
   3969     // illegal; expand it into a SELECT_CC.
   3970     EVT VT = Node->getValueType(0);
   3971     int TrueValue;
   3972     switch (TLI.getBooleanContents(Tmp1->getValueType(0))) {
   3973     case TargetLowering::ZeroOrOneBooleanContent:
   3974     case TargetLowering::UndefinedBooleanContent:
   3975       TrueValue = 1;
   3976       break;
   3977     case TargetLowering::ZeroOrNegativeOneBooleanContent:
   3978       TrueValue = -1;
   3979       break;
   3980     }
   3981     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
   3982                        DAG.getConstant(TrueValue, VT), DAG.getConstant(0, VT),
   3983                        Tmp3);
   3984     Results.push_back(Tmp1);
   3985     break;
   3986   }
   3987   case ISD::SELECT_CC: {
   3988     Tmp1 = Node->getOperand(0);   // LHS
   3989     Tmp2 = Node->getOperand(1);   // RHS
   3990     Tmp3 = Node->getOperand(2);   // True
   3991     Tmp4 = Node->getOperand(3);   // False
   3992     EVT VT = Node->getValueType(0);
   3993     SDValue CC = Node->getOperand(4);
   3994     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
   3995 
   3996     if (TLI.isCondCodeLegal(CCOp, Tmp1.getSimpleValueType())) {
   3997       // If the condition code is legal, then we need to expand this
   3998       // node using SETCC and SELECT.
   3999       EVT CmpVT = Tmp1.getValueType();
   4000       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
   4001              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
   4002              "expanded.");
   4003       EVT CCVT = TLI.getSetCCResultType(*DAG.getContext(), CmpVT);
   4004       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC);
   4005       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
   4006       break;
   4007     }
   4008 
   4009     // SELECT_CC is legal, so the condition code must not be.
   4010     bool Legalized = false;
   4011     // Try to legalize by inverting the condition.  This is for targets that
   4012     // might support an ordered version of a condition, but not the unordered
   4013     // version (or vice versa).
   4014     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp,
   4015                                                Tmp1.getValueType().isInteger());
   4016     if (TLI.isCondCodeLegal(InvCC, Tmp1.getSimpleValueType())) {
   4017       // Use the new condition code and swap true and false
   4018       Legalized = true;
   4019       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
   4020     } else {
   4021       // If The inverse is not legal, then try to swap the arguments using
   4022       // the inverse condition code.
   4023       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
   4024       if (TLI.isCondCodeLegal(SwapInvCC, Tmp1.getSimpleValueType())) {
   4025         // The swapped inverse condition is legal, so swap true and false,
   4026         // lhs and rhs.
   4027         Legalized = true;
   4028         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
   4029       }
   4030     }
   4031 
   4032     if (!Legalized) {
   4033       Legalized = LegalizeSetCCCondCode(
   4034           getSetCCResultType(Tmp1.getValueType()), Tmp1, Tmp2, CC, NeedInvert,
   4035           dl);
   4036 
   4037       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
   4038 
   4039       // If we expanded the SETCC by inverting the condition code, then swap
   4040       // the True/False operands to match.
   4041       if (NeedInvert)
   4042         std::swap(Tmp3, Tmp4);
   4043 
   4044       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
   4045       // condition code, create a new SELECT_CC node.
   4046       if (CC.getNode()) {
   4047         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
   4048                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
   4049       } else {
   4050         Tmp2 = DAG.getConstant(0, Tmp1.getValueType());
   4051         CC = DAG.getCondCode(ISD::SETNE);
   4052         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
   4053                            Tmp2, Tmp3, Tmp4, CC);
   4054       }
   4055     }
   4056     Results.push_back(Tmp1);
   4057     break;
   4058   }
   4059   case ISD::BR_CC: {
   4060     Tmp1 = Node->getOperand(0);              // Chain
   4061     Tmp2 = Node->getOperand(2);              // LHS
   4062     Tmp3 = Node->getOperand(3);              // RHS
   4063     Tmp4 = Node->getOperand(1);              // CC
   4064 
   4065     bool Legalized = LegalizeSetCCCondCode(getSetCCResultType(
   4066         Tmp2.getValueType()), Tmp2, Tmp3, Tmp4, NeedInvert, dl);
   4067     (void)Legalized;
   4068     assert(Legalized && "Can't legalize BR_CC with legal condition!");
   4069 
   4070     // If we expanded the SETCC by inverting the condition code, then wrap
   4071     // the existing SETCC in a NOT to restore the intended condition.
   4072     if (NeedInvert)
   4073       Tmp4 = DAG.getNOT(dl, Tmp4, Tmp4->getValueType(0));
   4074 
   4075     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
   4076     // node.
   4077     if (Tmp4.getNode()) {
   4078       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
   4079                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
   4080     } else {
   4081       Tmp3 = DAG.getConstant(0, Tmp2.getValueType());
   4082       Tmp4 = DAG.getCondCode(ISD::SETNE);
   4083       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
   4084                          Tmp2, Tmp3, Node->getOperand(4));
   4085     }
   4086     Results.push_back(Tmp1);
   4087     break;
   4088   }
   4089   case ISD::BUILD_VECTOR:
   4090     Results.push_back(ExpandBUILD_VECTOR(Node));
   4091     break;
   4092   case ISD::SRA:
   4093   case ISD::SRL:
   4094   case ISD::SHL: {
   4095     // Scalarize vector SRA/SRL/SHL.
   4096     EVT VT = Node->getValueType(0);
   4097     assert(VT.isVector() && "Unable to legalize non-vector shift");
   4098     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
   4099     unsigned NumElem = VT.getVectorNumElements();
   4100 
   4101     SmallVector<SDValue, 8> Scalars;
   4102     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
   4103       SDValue Ex = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
   4104                                VT.getScalarType(),
   4105                                Node->getOperand(0), DAG.getConstant(Idx,
   4106                                                     TLI.getVectorIdxTy()));
   4107       SDValue Sh = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
   4108                                VT.getScalarType(),
   4109                                Node->getOperand(1), DAG.getConstant(Idx,
   4110                                                     TLI.getVectorIdxTy()));
   4111       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
   4112                                     VT.getScalarType(), Ex, Sh));
   4113     }
   4114     SDValue Result =
   4115       DAG.getNode(ISD::BUILD_VECTOR, dl, Node->getValueType(0), Scalars);
   4116     ReplaceNode(SDValue(Node, 0), Result);
   4117     break;
   4118   }
   4119   case ISD::GLOBAL_OFFSET_TABLE:
   4120   case ISD::GlobalAddress:
   4121   case ISD::GlobalTLSAddress:
   4122   case ISD::ExternalSymbol:
   4123   case ISD::ConstantPool:
   4124   case ISD::JumpTable:
   4125   case ISD::INTRINSIC_W_CHAIN:
   4126   case ISD::INTRINSIC_WO_CHAIN:
   4127   case ISD::INTRINSIC_VOID:
   4128     // FIXME: Custom lowering for these operations shouldn't return null!
   4129     break;
   4130   }
   4131 
   4132   // Replace the original node with the legalized result.
   4133   if (!Results.empty())
   4134     ReplaceNode(Node, Results.data());
   4135 }
   4136 
   4137 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
   4138   SmallVector<SDValue, 8> Results;
   4139   MVT OVT = Node->getSimpleValueType(0);
   4140   if (Node->getOpcode() == ISD::UINT_TO_FP ||
   4141       Node->getOpcode() == ISD::SINT_TO_FP ||
   4142       Node->getOpcode() == ISD::SETCC) {
   4143     OVT = Node->getOperand(0).getSimpleValueType();
   4144   }
   4145   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
   4146   SDLoc dl(Node);
   4147   SDValue Tmp1, Tmp2, Tmp3;
   4148   switch (Node->getOpcode()) {
   4149   case ISD::CTTZ:
   4150   case ISD::CTTZ_ZERO_UNDEF:
   4151   case ISD::CTLZ:
   4152   case ISD::CTLZ_ZERO_UNDEF:
   4153   case ISD::CTPOP:
   4154     // Zero extend the argument.
   4155     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
   4156     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
   4157     // already the correct result.
   4158     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
   4159     if (Node->getOpcode() == ISD::CTTZ) {
   4160       // FIXME: This should set a bit in the zero extended value instead.
   4161       Tmp2 = DAG.getSetCC(dl, getSetCCResultType(NVT),
   4162                           Tmp1, DAG.getConstant(NVT.getSizeInBits(), NVT),
   4163                           ISD::SETEQ);
   4164       Tmp1 = DAG.getSelect(dl, NVT, Tmp2,
   4165                            DAG.getConstant(OVT.getSizeInBits(), NVT), Tmp1);
   4166     } else if (Node->getOpcode() == ISD::CTLZ ||
   4167                Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
   4168       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
   4169       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
   4170                           DAG.getConstant(NVT.getSizeInBits() -
   4171                                           OVT.getSizeInBits(), NVT));
   4172     }
   4173     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
   4174     break;
   4175   case ISD::BSWAP: {
   4176     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
   4177     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
   4178     Tmp1 = DAG.getNode(ISD::BSWAP, dl, NVT, Tmp1);
   4179     Tmp1 = DAG.getNode(ISD::SRL, dl, NVT, Tmp1,
   4180                           DAG.getConstant(DiffBits, TLI.getShiftAmountTy(NVT)));
   4181     Results.push_back(Tmp1);
   4182     break;
   4183   }
   4184   case ISD::FP_TO_UINT:
   4185   case ISD::FP_TO_SINT:
   4186     Tmp1 = PromoteLegalFP_TO_INT(Node->getOperand(0), Node->getValueType(0),
   4187                                  Node->getOpcode() == ISD::FP_TO_SINT, dl);
   4188     Results.push_back(Tmp1);
   4189     break;
   4190   case ISD::UINT_TO_FP:
   4191   case ISD::SINT_TO_FP:
   4192     Tmp1 = PromoteLegalINT_TO_FP(Node->getOperand(0), Node->getValueType(0),
   4193                                  Node->getOpcode() == ISD::SINT_TO_FP, dl);
   4194     Results.push_back(Tmp1);
   4195     break;
   4196   case ISD::VAARG: {
   4197     SDValue Chain = Node->getOperand(0); // Get the chain.
   4198     SDValue Ptr = Node->getOperand(1); // Get the pointer.
   4199 
   4200     unsigned TruncOp;
   4201     if (OVT.isVector()) {
   4202       TruncOp = ISD::BITCAST;
   4203     } else {
   4204       assert(OVT.isInteger()
   4205         && "VAARG promotion is supported only for vectors or integer types");
   4206       TruncOp = ISD::TRUNCATE;
   4207     }
   4208 
   4209     // Perform the larger operation, then convert back
   4210     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
   4211              Node->getConstantOperandVal(3));
   4212     Chain = Tmp1.getValue(1);
   4213 
   4214     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
   4215 
   4216     // Modified the chain result - switch anything that used the old chain to
   4217     // use the new one.
   4218     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
   4219     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
   4220     ReplacedNode(Node);
   4221     break;
   4222   }
   4223   case ISD::AND:
   4224   case ISD::OR:
   4225   case ISD::XOR: {
   4226     unsigned ExtOp, TruncOp;
   4227     if (OVT.isVector()) {
   4228       ExtOp   = ISD::BITCAST;
   4229       TruncOp = ISD::BITCAST;
   4230     } else {
   4231       assert(OVT.isInteger() && "Cannot promote logic operation");
   4232       ExtOp   = ISD::ANY_EXTEND;
   4233       TruncOp = ISD::TRUNCATE;
   4234     }
   4235     // Promote each of the values to the new type.
   4236     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
   4237     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
   4238     // Perform the larger operation, then convert back
   4239     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
   4240     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
   4241     break;
   4242   }
   4243   case ISD::SELECT: {
   4244     unsigned ExtOp, TruncOp;
   4245     if (Node->getValueType(0).isVector() ||
   4246         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
   4247       ExtOp   = ISD::BITCAST;
   4248       TruncOp = ISD::BITCAST;
   4249     } else if (Node->getValueType(0).isInteger()) {
   4250       ExtOp   = ISD::ANY_EXTEND;
   4251       TruncOp = ISD::TRUNCATE;
   4252     } else {
   4253       ExtOp   = ISD::FP_EXTEND;
   4254       TruncOp = ISD::FP_ROUND;
   4255     }
   4256     Tmp1 = Node->getOperand(0);
   4257     // Promote each of the values to the new type.
   4258     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
   4259     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
   4260     // Perform the larger operation, then round down.
   4261     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
   4262     if (TruncOp != ISD::FP_ROUND)
   4263       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
   4264     else
   4265       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
   4266                          DAG.getIntPtrConstant(0));
   4267     Results.push_back(Tmp1);
   4268     break;
   4269   }
   4270   case ISD::VECTOR_SHUFFLE: {
   4271     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
   4272 
   4273     // Cast the two input vectors.
   4274     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
   4275     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
   4276 
   4277     // Convert the shuffle mask to the right # elements.
   4278     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
   4279     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
   4280     Results.push_back(Tmp1);
   4281     break;
   4282   }
   4283   case ISD::SETCC: {
   4284     unsigned ExtOp = ISD::FP_EXTEND;
   4285     if (NVT.isInteger()) {
   4286       ISD::CondCode CCCode =
   4287         cast<CondCodeSDNode>(Node->getOperand(2))->get();
   4288       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
   4289     }
   4290     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
   4291     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
   4292     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
   4293                                   Tmp1, Tmp2, Node->getOperand(2)));
   4294     break;
   4295   }
   4296   case ISD::FDIV:
   4297   case ISD::FREM:
   4298   case ISD::FPOW: {
   4299     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
   4300     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
   4301     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
   4302     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
   4303                                   Tmp3, DAG.getIntPtrConstant(0)));
   4304     break;
   4305   }
   4306   case ISD::FLOG2:
   4307   case ISD::FEXP2:
   4308   case ISD::FLOG:
   4309   case ISD::FEXP: {
   4310     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
   4311     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
   4312     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
   4313                                   Tmp2, DAG.getIntPtrConstant(0)));
   4314     break;
   4315   }
   4316   }
   4317 
   4318   // Replace the original node with the legalized result.
   4319   if (!Results.empty())
   4320     ReplaceNode(Node, Results.data());
   4321 }
   4322 
   4323 // SelectionDAG::Legalize - This is the entry point for the file.
   4324 //
   4325 void SelectionDAG::Legalize() {
   4326   /// run - This is the main entry point to this class.
   4327   ///
   4328   SelectionDAGLegalize(*this).LegalizeDAG();
   4329 }
   4330