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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/CallingConv.h"
     15 #include "llvm/Constants.h"
     16 #include "llvm/DebugInfo.h"
     17 #include "llvm/DerivedTypes.h"
     18 #include "llvm/LLVMContext.h"
     19 #include "llvm/CodeGen/Analysis.h"
     20 #include "llvm/CodeGen/MachineFunction.h"
     21 #include "llvm/CodeGen/MachineJumpTableInfo.h"
     22 #include "llvm/CodeGen/SelectionDAG.h"
     23 #include "llvm/Target/TargetFrameLowering.h"
     24 #include "llvm/Target/TargetLowering.h"
     25 #include "llvm/Target/TargetData.h"
     26 #include "llvm/Target/TargetMachine.h"
     27 #include "llvm/Support/Debug.h"
     28 #include "llvm/Support/ErrorHandling.h"
     29 #include "llvm/Support/MathExtras.h"
     30 #include "llvm/Support/raw_ostream.h"
     31 #include "llvm/ADT/DenseMap.h"
     32 #include "llvm/ADT/SmallVector.h"
     33 #include "llvm/ADT/SmallPtrSet.h"
     34 using namespace llvm;
     35 
     36 //===----------------------------------------------------------------------===//
     37 /// SelectionDAGLegalize - This takes an arbitrary SelectionDAG as input and
     38 /// hacks on it until the target machine can handle it.  This involves
     39 /// eliminating value sizes the machine cannot handle (promoting small sizes to
     40 /// large sizes or splitting up large values into small values) as well as
     41 /// eliminating operations the machine cannot handle.
     42 ///
     43 /// This code also does a small amount of optimization and recognition of idioms
     44 /// as part of its processing.  For example, if a target does not support a
     45 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
     46 /// will attempt merge setcc and brc instructions into brcc's.
     47 ///
     48 namespace {
     49 class SelectionDAGLegalize : public SelectionDAG::DAGUpdateListener {
     50   const TargetMachine &TM;
     51   const TargetLowering &TLI;
     52   SelectionDAG &DAG;
     53 
     54   /// LegalizePosition - The iterator for walking through the node list.
     55   SelectionDAG::allnodes_iterator LegalizePosition;
     56 
     57   /// LegalizedNodes - The set of nodes which have already been legalized.
     58   SmallPtrSet<SDNode *, 16> LegalizedNodes;
     59 
     60   // Libcall insertion helpers.
     61 
     62 public:
     63   explicit SelectionDAGLegalize(SelectionDAG &DAG);
     64 
     65   void LegalizeDAG();
     66 
     67 private:
     68   /// LegalizeOp - Legalizes the given operation.
     69   void LegalizeOp(SDNode *Node);
     70 
     71   SDValue OptimizeFloatStore(StoreSDNode *ST);
     72 
     73   void LegalizeLoadOps(SDNode *Node);
     74   void LegalizeStoreOps(SDNode *Node);
     75 
     76   /// PerformInsertVectorEltInMemory - Some target cannot handle a variable
     77   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
     78   /// is necessary to spill the vector being inserted into to memory, perform
     79   /// the insert there, and then read the result back.
     80   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val,
     81                                          SDValue Idx, DebugLoc dl);
     82   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
     83                                   SDValue Idx, DebugLoc dl);
     84 
     85   /// ShuffleWithNarrowerEltType - Return a vector shuffle operation which
     86   /// performs the same shuffe in terms of order or result bytes, but on a type
     87   /// whose vector element type is narrower than the original shuffle type.
     88   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
     89   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, DebugLoc dl,
     90                                      SDValue N1, SDValue N2,
     91                                      ArrayRef<int> Mask) const;
     92 
     93   void LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
     94                              DebugLoc dl);
     95 
     96   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
     97   SDValue ExpandLibCall(RTLIB::Libcall LC, EVT RetVT, const SDValue *Ops,
     98                         unsigned NumOps, bool isSigned, DebugLoc dl);
     99 
    100   std::pair<SDValue, SDValue> ExpandChainLibCall(RTLIB::Libcall LC,
    101                                                  SDNode *Node, bool isSigned);
    102   SDValue ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
    103                           RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
    104                           RTLIB::Libcall Call_PPCF128);
    105   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
    106                            RTLIB::Libcall Call_I8,
    107                            RTLIB::Libcall Call_I16,
    108                            RTLIB::Libcall Call_I32,
    109                            RTLIB::Libcall Call_I64,
    110                            RTLIB::Libcall Call_I128);
    111   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
    112 
    113   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT, DebugLoc dl);
    114   SDValue ExpandBUILD_VECTOR(SDNode *Node);
    115   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
    116   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
    117                                 SmallVectorImpl<SDValue> &Results);
    118   SDValue ExpandFCOPYSIGN(SDNode *Node);
    119   SDValue ExpandLegalINT_TO_FP(bool isSigned, SDValue LegalOp, EVT DestVT,
    120                                DebugLoc dl);
    121   SDValue PromoteLegalINT_TO_FP(SDValue LegalOp, EVT DestVT, bool isSigned,
    122                                 DebugLoc dl);
    123   SDValue PromoteLegalFP_TO_INT(SDValue LegalOp, EVT DestVT, bool isSigned,
    124                                 DebugLoc dl);
    125 
    126   SDValue ExpandBSWAP(SDValue Op, DebugLoc dl);
    127   SDValue ExpandBitCount(unsigned Opc, SDValue Op, DebugLoc dl);
    128 
    129   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
    130   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
    131   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
    132 
    133   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
    134 
    135   std::pair<SDValue, SDValue> ExpandAtomic(SDNode *Node);
    136 
    137   void ExpandNode(SDNode *Node);
    138   void PromoteNode(SDNode *Node);
    139 
    140   void ForgetNode(SDNode *N) {
    141     LegalizedNodes.erase(N);
    142     if (LegalizePosition == SelectionDAG::allnodes_iterator(N))
    143       ++LegalizePosition;
    144   }
    145 
    146 public:
    147   // DAGUpdateListener implementation.
    148   virtual void NodeDeleted(SDNode *N, SDNode *E) {
    149     ForgetNode(N);
    150   }
    151   virtual void NodeUpdated(SDNode *N) {}
    152 
    153   // Node replacement helpers
    154   void ReplacedNode(SDNode *N) {
    155     if (N->use_empty()) {
    156       DAG.RemoveDeadNode(N);
    157     } else {
    158       ForgetNode(N);
    159     }
    160   }
    161   void ReplaceNode(SDNode *Old, SDNode *New) {
    162     DAG.ReplaceAllUsesWith(Old, New);
    163     ReplacedNode(Old);
    164   }
    165   void ReplaceNode(SDValue Old, SDValue New) {
    166     DAG.ReplaceAllUsesWith(Old, New);
    167     ReplacedNode(Old.getNode());
    168   }
    169   void ReplaceNode(SDNode *Old, const SDValue *New) {
    170     DAG.ReplaceAllUsesWith(Old, New);
    171     ReplacedNode(Old);
    172   }
    173 };
    174 }
    175 
    176 /// ShuffleWithNarrowerEltType - Return a vector shuffle operation which
    177 /// performs the same shuffe in terms of order or result bytes, but on a type
    178 /// whose vector element type is narrower than the original shuffle type.
    179 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
    180 SDValue
    181 SelectionDAGLegalize::ShuffleWithNarrowerEltType(EVT NVT, EVT VT,  DebugLoc dl,
    182                                                  SDValue N1, SDValue N2,
    183                                                  ArrayRef<int> Mask) const {
    184   unsigned NumMaskElts = VT.getVectorNumElements();
    185   unsigned NumDestElts = NVT.getVectorNumElements();
    186   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
    187 
    188   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
    189 
    190   if (NumEltsGrowth == 1)
    191     return DAG.getVectorShuffle(NVT, dl, N1, N2, &Mask[0]);
    192 
    193   SmallVector<int, 8> NewMask;
    194   for (unsigned i = 0; i != NumMaskElts; ++i) {
    195     int Idx = Mask[i];
    196     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
    197       if (Idx < 0)
    198         NewMask.push_back(-1);
    199       else
    200         NewMask.push_back(Idx * NumEltsGrowth + j);
    201     }
    202   }
    203   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
    204   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
    205   return DAG.getVectorShuffle(NVT, dl, N1, N2, &NewMask[0]);
    206 }
    207 
    208 SelectionDAGLegalize::SelectionDAGLegalize(SelectionDAG &dag)
    209   : SelectionDAG::DAGUpdateListener(dag),
    210     TM(dag.getTarget()), TLI(dag.getTargetLoweringInfo()),
    211     DAG(dag) {
    212 }
    213 
    214 void SelectionDAGLegalize::LegalizeDAG() {
    215   DAG.AssignTopologicalOrder();
    216 
    217   // Visit all the nodes. We start in topological order, so that we see
    218   // nodes with their original operands intact. Legalization can produce
    219   // new nodes which may themselves need to be legalized. Iterate until all
    220   // nodes have been legalized.
    221   for (;;) {
    222     bool AnyLegalized = false;
    223     for (LegalizePosition = DAG.allnodes_end();
    224          LegalizePosition != DAG.allnodes_begin(); ) {
    225       --LegalizePosition;
    226 
    227       SDNode *N = LegalizePosition;
    228       if (LegalizedNodes.insert(N)) {
    229         AnyLegalized = true;
    230         LegalizeOp(N);
    231       }
    232     }
    233     if (!AnyLegalized)
    234       break;
    235 
    236   }
    237 
    238   // Remove dead nodes now.
    239   DAG.RemoveDeadNodes();
    240 }
    241 
    242 /// ExpandConstantFP - Expands the ConstantFP node to an integer constant or
    243 /// a load from the constant pool.
    244 SDValue
    245 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
    246   bool Extend = false;
    247   DebugLoc dl = CFP->getDebugLoc();
    248 
    249   // If a FP immediate is precise when represented as a float and if the
    250   // target can do an extending load from float to double, we put it into
    251   // the constant pool as a float, even if it's is statically typed as a
    252   // double.  This shrinks FP constants and canonicalizes them for targets where
    253   // an FP extending load is the same cost as a normal load (such as on the x87
    254   // fp stack or PPC FP unit).
    255   EVT VT = CFP->getValueType(0);
    256   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
    257   if (!UseCP) {
    258     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
    259     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(),
    260                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
    261   }
    262 
    263   EVT OrigVT = VT;
    264   EVT SVT = VT;
    265   while (SVT != MVT::f32) {
    266     SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
    267     if (ConstantFPSDNode::isValueValidForType(SVT, CFP->getValueAPF()) &&
    268         // Only do this if the target has a native EXTLOAD instruction from
    269         // smaller type.
    270         TLI.isLoadExtLegal(ISD::EXTLOAD, SVT) &&
    271         TLI.ShouldShrinkFPConstant(OrigVT)) {
    272       Type *SType = SVT.getTypeForEVT(*DAG.getContext());
    273       LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
    274       VT = SVT;
    275       Extend = true;
    276     }
    277   }
    278 
    279   SDValue CPIdx = DAG.getConstantPool(LLVMC, TLI.getPointerTy());
    280   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
    281   if (Extend) {
    282     SDValue Result =
    283       DAG.getExtLoad(ISD::EXTLOAD, dl, OrigVT,
    284                      DAG.getEntryNode(),
    285                      CPIdx, MachinePointerInfo::getConstantPool(),
    286                      VT, false, false, Alignment);
    287     return Result;
    288   }
    289   SDValue Result =
    290     DAG.getLoad(OrigVT, dl, DAG.getEntryNode(), CPIdx,
    291                 MachinePointerInfo::getConstantPool(), false, false, false,
    292                 Alignment);
    293   return Result;
    294 }
    295 
    296 /// ExpandUnalignedStore - Expands an unaligned store to 2 half-size stores.
    297 static void ExpandUnalignedStore(StoreSDNode *ST, SelectionDAG &DAG,
    298                                  const TargetLowering &TLI,
    299                                  SelectionDAGLegalize *DAGLegalize) {
    300   assert(ST->getAddressingMode() == ISD::UNINDEXED &&
    301          "unaligned indexed stores not implemented!");
    302   SDValue Chain = ST->getChain();
    303   SDValue Ptr = ST->getBasePtr();
    304   SDValue Val = ST->getValue();
    305   EVT VT = Val.getValueType();
    306   int Alignment = ST->getAlignment();
    307   DebugLoc dl = ST->getDebugLoc();
    308   if (ST->getMemoryVT().isFloatingPoint() ||
    309       ST->getMemoryVT().isVector()) {
    310     EVT intVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
    311     if (TLI.isTypeLegal(intVT)) {
    312       // Expand to a bitconvert of the value to the integer type of the
    313       // same size, then a (misaligned) int store.
    314       // FIXME: Does not handle truncating floating point stores!
    315       SDValue Result = DAG.getNode(ISD::BITCAST, dl, intVT, Val);
    316       Result = DAG.getStore(Chain, dl, Result, Ptr, ST->getPointerInfo(),
    317                            ST->isVolatile(), ST->isNonTemporal(), Alignment);
    318       DAGLegalize->ReplaceNode(SDValue(ST, 0), Result);
    319       return;
    320     }
    321     // Do a (aligned) store to a stack slot, then copy from the stack slot
    322     // to the final destination using (unaligned) integer loads and stores.
    323     EVT StoredVT = ST->getMemoryVT();
    324     EVT RegVT =
    325       TLI.getRegisterType(*DAG.getContext(),
    326                           EVT::getIntegerVT(*DAG.getContext(),
    327                                             StoredVT.getSizeInBits()));
    328     unsigned StoredBytes = StoredVT.getSizeInBits() / 8;
    329     unsigned RegBytes = RegVT.getSizeInBits() / 8;
    330     unsigned NumRegs = (StoredBytes + RegBytes - 1) / RegBytes;
    331 
    332     // Make sure the stack slot is also aligned for the register type.
    333     SDValue StackPtr = DAG.CreateStackTemporary(StoredVT, RegVT);
    334 
    335     // Perform the original store, only redirected to the stack slot.
    336     SDValue Store = DAG.getTruncStore(Chain, dl,
    337                                       Val, StackPtr, MachinePointerInfo(),
    338                                       StoredVT, false, false, 0);
    339     SDValue Increment = DAG.getConstant(RegBytes, TLI.getPointerTy());
    340     SmallVector<SDValue, 8> Stores;
    341     unsigned Offset = 0;
    342 
    343     // Do all but one copies using the full register width.
    344     for (unsigned i = 1; i < NumRegs; i++) {
    345       // Load one integer register's worth from the stack slot.
    346       SDValue Load = DAG.getLoad(RegVT, dl, Store, StackPtr,
    347                                  MachinePointerInfo(),
    348                                  false, false, false, 0);
    349       // Store it to the final location.  Remember the store.
    350       Stores.push_back(DAG.getStore(Load.getValue(1), dl, Load, Ptr,
    351                                   ST->getPointerInfo().getWithOffset(Offset),
    352                                     ST->isVolatile(), ST->isNonTemporal(),
    353                                     MinAlign(ST->getAlignment(), Offset)));
    354       // Increment the pointers.
    355       Offset += RegBytes;
    356       StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
    357                              Increment);
    358       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, Increment);
    359     }
    360 
    361     // The last store may be partial.  Do a truncating store.  On big-endian
    362     // machines this requires an extending load from the stack slot to ensure
    363     // that the bits are in the right place.
    364     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(),
    365                                   8 * (StoredBytes - Offset));
    366 
    367     // Load from the stack slot.
    368     SDValue Load = DAG.getExtLoad(ISD::EXTLOAD, dl, RegVT, Store, StackPtr,
    369                                   MachinePointerInfo(),
    370                                   MemVT, false, false, 0);
    371 
    372     Stores.push_back(DAG.getTruncStore(Load.getValue(1), dl, Load, Ptr,
    373                                        ST->getPointerInfo()
    374                                          .getWithOffset(Offset),
    375                                        MemVT, ST->isVolatile(),
    376                                        ST->isNonTemporal(),
    377                                        MinAlign(ST->getAlignment(), Offset)));
    378     // The order of the stores doesn't matter - say it with a TokenFactor.
    379     SDValue Result =
    380       DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &Stores[0],
    381                   Stores.size());
    382     DAGLegalize->ReplaceNode(SDValue(ST, 0), Result);
    383     return;
    384   }
    385   assert(ST->getMemoryVT().isInteger() &&
    386          !ST->getMemoryVT().isVector() &&
    387          "Unaligned store of unknown type.");
    388   // Get the half-size VT
    389   EVT NewStoredVT = ST->getMemoryVT().getHalfSizedIntegerVT(*DAG.getContext());
    390   int NumBits = NewStoredVT.getSizeInBits();
    391   int IncrementSize = NumBits / 8;
    392 
    393   // Divide the stored value in two parts.
    394   SDValue ShiftAmount = DAG.getConstant(NumBits,
    395                                       TLI.getShiftAmountTy(Val.getValueType()));
    396   SDValue Lo = Val;
    397   SDValue Hi = DAG.getNode(ISD::SRL, dl, VT, Val, ShiftAmount);
    398 
    399   // Store the two parts
    400   SDValue Store1, Store2;
    401   Store1 = DAG.getTruncStore(Chain, dl, TLI.isLittleEndian()?Lo:Hi, Ptr,
    402                              ST->getPointerInfo(), NewStoredVT,
    403                              ST->isVolatile(), ST->isNonTemporal(), Alignment);
    404   Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    405                     DAG.getConstant(IncrementSize, TLI.getPointerTy()));
    406   Alignment = MinAlign(Alignment, IncrementSize);
    407   Store2 = DAG.getTruncStore(Chain, dl, TLI.isLittleEndian()?Hi:Lo, Ptr,
    408                              ST->getPointerInfo().getWithOffset(IncrementSize),
    409                              NewStoredVT, ST->isVolatile(), ST->isNonTemporal(),
    410                              Alignment);
    411 
    412   SDValue Result =
    413     DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Store1, Store2);
    414   DAGLegalize->ReplaceNode(SDValue(ST, 0), Result);
    415 }
    416 
    417 /// ExpandUnalignedLoad - Expands an unaligned load to 2 half-size loads.
    418 static void
    419 ExpandUnalignedLoad(LoadSDNode *LD, SelectionDAG &DAG,
    420                     const TargetLowering &TLI,
    421                     SDValue &ValResult, SDValue &ChainResult) {
    422   assert(LD->getAddressingMode() == ISD::UNINDEXED &&
    423          "unaligned indexed loads not implemented!");
    424   SDValue Chain = LD->getChain();
    425   SDValue Ptr = LD->getBasePtr();
    426   EVT VT = LD->getValueType(0);
    427   EVT LoadedVT = LD->getMemoryVT();
    428   DebugLoc dl = LD->getDebugLoc();
    429   if (VT.isFloatingPoint() || VT.isVector()) {
    430     EVT intVT = EVT::getIntegerVT(*DAG.getContext(), LoadedVT.getSizeInBits());
    431     if (TLI.isTypeLegal(intVT) && TLI.isTypeLegal(LoadedVT)) {
    432       // Expand to a (misaligned) integer load of the same size,
    433       // then bitconvert to floating point or vector.
    434       SDValue newLoad = DAG.getLoad(intVT, dl, Chain, Ptr, LD->getPointerInfo(),
    435                                     LD->isVolatile(),
    436                                     LD->isNonTemporal(),
    437                                     LD->isInvariant(), LD->getAlignment());
    438       SDValue Result = DAG.getNode(ISD::BITCAST, dl, LoadedVT, newLoad);
    439       if (LoadedVT != VT)
    440         Result = DAG.getNode(VT.isFloatingPoint() ? ISD::FP_EXTEND :
    441                              ISD::ANY_EXTEND, dl, VT, Result);
    442 
    443       ValResult = Result;
    444       ChainResult = Chain;
    445       return;
    446     }
    447 
    448     // Copy the value to a (aligned) stack slot using (unaligned) integer
    449     // loads and stores, then do a (aligned) load from the stack slot.
    450     EVT RegVT = TLI.getRegisterType(*DAG.getContext(), intVT);
    451     unsigned LoadedBytes = LoadedVT.getSizeInBits() / 8;
    452     unsigned RegBytes = RegVT.getSizeInBits() / 8;
    453     unsigned NumRegs = (LoadedBytes + RegBytes - 1) / RegBytes;
    454 
    455     // Make sure the stack slot is also aligned for the register type.
    456     SDValue StackBase = DAG.CreateStackTemporary(LoadedVT, RegVT);
    457 
    458     SDValue Increment = DAG.getConstant(RegBytes, TLI.getPointerTy());
    459     SmallVector<SDValue, 8> Stores;
    460     SDValue StackPtr = StackBase;
    461     unsigned Offset = 0;
    462 
    463     // Do all but one copies using the full register width.
    464     for (unsigned i = 1; i < NumRegs; i++) {
    465       // Load one integer register's worth from the original location.
    466       SDValue Load = DAG.getLoad(RegVT, dl, Chain, Ptr,
    467                                  LD->getPointerInfo().getWithOffset(Offset),
    468                                  LD->isVolatile(), LD->isNonTemporal(),
    469                                  LD->isInvariant(),
    470                                  MinAlign(LD->getAlignment(), Offset));
    471       // Follow the load with a store to the stack slot.  Remember the store.
    472       Stores.push_back(DAG.getStore(Load.getValue(1), dl, Load, StackPtr,
    473                                     MachinePointerInfo(), false, false, 0));
    474       // Increment the pointers.
    475       Offset += RegBytes;
    476       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr, Increment);
    477       StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
    478                              Increment);
    479     }
    480 
    481     // The last copy may be partial.  Do an extending load.
    482     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(),
    483                                   8 * (LoadedBytes - Offset));
    484     SDValue Load = DAG.getExtLoad(ISD::EXTLOAD, dl, RegVT, Chain, Ptr,
    485                                   LD->getPointerInfo().getWithOffset(Offset),
    486                                   MemVT, LD->isVolatile(),
    487                                   LD->isNonTemporal(),
    488                                   MinAlign(LD->getAlignment(), Offset));
    489     // Follow the load with a store to the stack slot.  Remember the store.
    490     // On big-endian machines this requires a truncating store to ensure
    491     // that the bits end up in the right place.
    492     Stores.push_back(DAG.getTruncStore(Load.getValue(1), dl, Load, StackPtr,
    493                                        MachinePointerInfo(), MemVT,
    494                                        false, false, 0));
    495 
    496     // The order of the stores doesn't matter - say it with a TokenFactor.
    497     SDValue TF = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &Stores[0],
    498                              Stores.size());
    499 
    500     // Finally, perform the original load only redirected to the stack slot.
    501     Load = DAG.getExtLoad(LD->getExtensionType(), dl, VT, TF, StackBase,
    502                           MachinePointerInfo(), LoadedVT, false, false, 0);
    503 
    504     // Callers expect a MERGE_VALUES node.
    505     ValResult = Load;
    506     ChainResult = TF;
    507     return;
    508   }
    509   assert(LoadedVT.isInteger() && !LoadedVT.isVector() &&
    510          "Unaligned load of unsupported type.");
    511 
    512   // Compute the new VT that is half the size of the old one.  This is an
    513   // integer MVT.
    514   unsigned NumBits = LoadedVT.getSizeInBits();
    515   EVT NewLoadedVT;
    516   NewLoadedVT = EVT::getIntegerVT(*DAG.getContext(), NumBits/2);
    517   NumBits >>= 1;
    518 
    519   unsigned Alignment = LD->getAlignment();
    520   unsigned IncrementSize = NumBits / 8;
    521   ISD::LoadExtType HiExtType = LD->getExtensionType();
    522 
    523   // If the original load is NON_EXTLOAD, the hi part load must be ZEXTLOAD.
    524   if (HiExtType == ISD::NON_EXTLOAD)
    525     HiExtType = ISD::ZEXTLOAD;
    526 
    527   // Load the value in two parts
    528   SDValue Lo, Hi;
    529   if (TLI.isLittleEndian()) {
    530     Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, VT, Chain, Ptr, LD->getPointerInfo(),
    531                         NewLoadedVT, LD->isVolatile(),
    532                         LD->isNonTemporal(), Alignment);
    533     Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    534                       DAG.getConstant(IncrementSize, TLI.getPointerTy()));
    535     Hi = DAG.getExtLoad(HiExtType, dl, VT, Chain, Ptr,
    536                         LD->getPointerInfo().getWithOffset(IncrementSize),
    537                         NewLoadedVT, LD->isVolatile(),
    538                         LD->isNonTemporal(), MinAlign(Alignment,IncrementSize));
    539   } else {
    540     Hi = DAG.getExtLoad(HiExtType, dl, VT, Chain, Ptr, LD->getPointerInfo(),
    541                         NewLoadedVT, LD->isVolatile(),
    542                         LD->isNonTemporal(), Alignment);
    543     Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    544                       DAG.getConstant(IncrementSize, TLI.getPointerTy()));
    545     Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, VT, Chain, Ptr,
    546                         LD->getPointerInfo().getWithOffset(IncrementSize),
    547                         NewLoadedVT, LD->isVolatile(),
    548                         LD->isNonTemporal(), MinAlign(Alignment,IncrementSize));
    549   }
    550 
    551   // aggregate the two parts
    552   SDValue ShiftAmount = DAG.getConstant(NumBits,
    553                                        TLI.getShiftAmountTy(Hi.getValueType()));
    554   SDValue Result = DAG.getNode(ISD::SHL, dl, VT, Hi, ShiftAmount);
    555   Result = DAG.getNode(ISD::OR, dl, VT, Result, Lo);
    556 
    557   SDValue TF = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
    558                              Hi.getValue(1));
    559 
    560   ValResult = Result;
    561   ChainResult = TF;
    562 }
    563 
    564 /// PerformInsertVectorEltInMemory - Some target cannot handle a variable
    565 /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
    566 /// is necessary to spill the vector being inserted into to memory, perform
    567 /// the insert there, and then read the result back.
    568 SDValue SelectionDAGLegalize::
    569 PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
    570                                DebugLoc dl) {
    571   SDValue Tmp1 = Vec;
    572   SDValue Tmp2 = Val;
    573   SDValue Tmp3 = Idx;
    574 
    575   // If the target doesn't support this, we have to spill the input vector
    576   // to a temporary stack slot, update the element, then reload it.  This is
    577   // badness.  We could also load the value into a vector register (either
    578   // with a "move to register" or "extload into register" instruction, then
    579   // permute it into place, if the idx is a constant and if the idx is
    580   // supported by the target.
    581   EVT VT    = Tmp1.getValueType();
    582   EVT EltVT = VT.getVectorElementType();
    583   EVT IdxVT = Tmp3.getValueType();
    584   EVT PtrVT = TLI.getPointerTy();
    585   SDValue StackPtr = DAG.CreateStackTemporary(VT);
    586 
    587   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
    588 
    589   // Store the vector.
    590   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Tmp1, StackPtr,
    591                             MachinePointerInfo::getFixedStack(SPFI),
    592                             false, false, 0);
    593 
    594   // Truncate or zero extend offset to target pointer type.
    595   unsigned CastOpc = IdxVT.bitsGT(PtrVT) ? ISD::TRUNCATE : ISD::ZERO_EXTEND;
    596   Tmp3 = DAG.getNode(CastOpc, dl, PtrVT, Tmp3);
    597   // Add the offset to the index.
    598   unsigned EltSize = EltVT.getSizeInBits()/8;
    599   Tmp3 = DAG.getNode(ISD::MUL, dl, IdxVT, Tmp3,DAG.getConstant(EltSize, IdxVT));
    600   SDValue StackPtr2 = DAG.getNode(ISD::ADD, dl, IdxVT, Tmp3, StackPtr);
    601   // Store the scalar value.
    602   Ch = DAG.getTruncStore(Ch, dl, Tmp2, StackPtr2, MachinePointerInfo(), EltVT,
    603                          false, false, 0);
    604   // Load the updated vector.
    605   return DAG.getLoad(VT, dl, Ch, StackPtr,
    606                      MachinePointerInfo::getFixedStack(SPFI), false, false,
    607                      false, 0);
    608 }
    609 
    610 
    611 SDValue SelectionDAGLegalize::
    612 ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx, DebugLoc dl) {
    613   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
    614     // SCALAR_TO_VECTOR requires that the type of the value being inserted
    615     // match the element type of the vector being created, except for
    616     // integers in which case the inserted value can be over width.
    617     EVT EltVT = Vec.getValueType().getVectorElementType();
    618     if (Val.getValueType() == EltVT ||
    619         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
    620       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
    621                                   Vec.getValueType(), Val);
    622 
    623       unsigned NumElts = Vec.getValueType().getVectorNumElements();
    624       // We generate a shuffle of InVec and ScVec, so the shuffle mask
    625       // should be 0,1,2,3,4,5... with the appropriate element replaced with
    626       // elt 0 of the RHS.
    627       SmallVector<int, 8> ShufOps;
    628       for (unsigned i = 0; i != NumElts; ++i)
    629         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
    630 
    631       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec,
    632                                   &ShufOps[0]);
    633     }
    634   }
    635   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
    636 }
    637 
    638 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
    639   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
    640   // FIXME: We shouldn't do this for TargetConstantFP's.
    641   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
    642   // to phase ordering between legalized code and the dag combiner.  This
    643   // probably means that we need to integrate dag combiner and legalizer
    644   // together.
    645   // We generally can't do this one for long doubles.
    646   SDValue Chain = ST->getChain();
    647   SDValue Ptr = ST->getBasePtr();
    648   unsigned Alignment = ST->getAlignment();
    649   bool isVolatile = ST->isVolatile();
    650   bool isNonTemporal = ST->isNonTemporal();
    651   DebugLoc dl = ST->getDebugLoc();
    652   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
    653     if (CFP->getValueType(0) == MVT::f32 &&
    654         TLI.isTypeLegal(MVT::i32)) {
    655       SDValue Con = DAG.getConstant(CFP->getValueAPF().
    656                                       bitcastToAPInt().zextOrTrunc(32),
    657                               MVT::i32);
    658       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
    659                           isVolatile, isNonTemporal, Alignment);
    660     }
    661 
    662     if (CFP->getValueType(0) == MVT::f64) {
    663       // If this target supports 64-bit registers, do a single 64-bit store.
    664       if (TLI.isTypeLegal(MVT::i64)) {
    665         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
    666                                   zextOrTrunc(64), MVT::i64);
    667         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
    668                             isVolatile, isNonTemporal, Alignment);
    669       }
    670 
    671       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
    672         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
    673         // stores.  If the target supports neither 32- nor 64-bits, this
    674         // xform is certainly not worth it.
    675         const APInt &IntVal =CFP->getValueAPF().bitcastToAPInt();
    676         SDValue Lo = DAG.getConstant(IntVal.trunc(32), MVT::i32);
    677         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), MVT::i32);
    678         if (TLI.isBigEndian()) std::swap(Lo, Hi);
    679 
    680         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(), isVolatile,
    681                           isNonTemporal, Alignment);
    682         Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    683                             DAG.getIntPtrConstant(4));
    684         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
    685                           ST->getPointerInfo().getWithOffset(4),
    686                           isVolatile, isNonTemporal, MinAlign(Alignment, 4U));
    687 
    688         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
    689       }
    690     }
    691   }
    692   return SDValue(0, 0);
    693 }
    694 
    695 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
    696     StoreSDNode *ST = cast<StoreSDNode>(Node);
    697     SDValue Chain = ST->getChain();
    698     SDValue Ptr = ST->getBasePtr();
    699     DebugLoc dl = Node->getDebugLoc();
    700 
    701     unsigned Alignment = ST->getAlignment();
    702     bool isVolatile = ST->isVolatile();
    703     bool isNonTemporal = ST->isNonTemporal();
    704 
    705     if (!ST->isTruncatingStore()) {
    706       if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
    707         ReplaceNode(ST, OptStore);
    708         return;
    709       }
    710 
    711       {
    712         SDValue Value = ST->getValue();
    713         EVT VT = Value.getValueType();
    714         switch (TLI.getOperationAction(ISD::STORE, VT)) {
    715         default: llvm_unreachable("This action is not supported yet!");
    716         case TargetLowering::Legal:
    717           // If this is an unaligned store and the target doesn't support it,
    718           // expand it.
    719           if (!TLI.allowsUnalignedMemoryAccesses(ST->getMemoryVT())) {
    720             Type *Ty = ST->getMemoryVT().getTypeForEVT(*DAG.getContext());
    721             unsigned ABIAlignment= TLI.getTargetData()->getABITypeAlignment(Ty);
    722             if (ST->getAlignment() < ABIAlignment)
    723               ExpandUnalignedStore(cast<StoreSDNode>(Node),
    724                                    DAG, TLI, this);
    725           }
    726           break;
    727         case TargetLowering::Custom: {
    728           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
    729           if (Res.getNode())
    730             ReplaceNode(SDValue(Node, 0), Res);
    731           return;
    732         }
    733         case TargetLowering::Promote: {
    734           assert(VT.isVector() && "Unknown legal promote case!");
    735           Value = DAG.getNode(ISD::BITCAST, dl,
    736                              TLI.getTypeToPromoteTo(ISD::STORE, VT), Value);
    737           SDValue Result =
    738             DAG.getStore(Chain, dl, Value, Ptr,
    739                          ST->getPointerInfo(), isVolatile,
    740                          isNonTemporal, Alignment);
    741           ReplaceNode(SDValue(Node, 0), Result);
    742           break;
    743         }
    744         }
    745         return;
    746       }
    747     } else {
    748       SDValue Value = ST->getValue();
    749 
    750       EVT StVT = ST->getMemoryVT();
    751       unsigned StWidth = StVT.getSizeInBits();
    752 
    753       if (StWidth != StVT.getStoreSizeInBits()) {
    754         // Promote to a byte-sized store with upper bits zero if not
    755         // storing an integral number of bytes.  For example, promote
    756         // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
    757         EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
    758                                     StVT.getStoreSizeInBits());
    759         Value = DAG.getZeroExtendInReg(Value, dl, StVT);
    760         SDValue Result =
    761           DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
    762                             NVT, isVolatile, isNonTemporal, Alignment);
    763         ReplaceNode(SDValue(Node, 0), Result);
    764       } else if (StWidth & (StWidth - 1)) {
    765         // If not storing a power-of-2 number of bits, expand as two stores.
    766         assert(!StVT.isVector() && "Unsupported truncstore!");
    767         unsigned RoundWidth = 1 << Log2_32(StWidth);
    768         assert(RoundWidth < StWidth);
    769         unsigned ExtraWidth = StWidth - RoundWidth;
    770         assert(ExtraWidth < RoundWidth);
    771         assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
    772                "Store size not an integral number of bytes!");
    773         EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
    774         EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
    775         SDValue Lo, Hi;
    776         unsigned IncrementSize;
    777 
    778         if (TLI.isLittleEndian()) {
    779           // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
    780           // Store the bottom RoundWidth bits.
    781           Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
    782                                  RoundVT,
    783                                  isVolatile, isNonTemporal, Alignment);
    784 
    785           // Store the remaining ExtraWidth bits.
    786           IncrementSize = RoundWidth / 8;
    787           Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    788                              DAG.getIntPtrConstant(IncrementSize));
    789           Hi = DAG.getNode(ISD::SRL, dl, Value.getValueType(), Value,
    790                            DAG.getConstant(RoundWidth,
    791                                     TLI.getShiftAmountTy(Value.getValueType())));
    792           Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr,
    793                              ST->getPointerInfo().getWithOffset(IncrementSize),
    794                                  ExtraVT, isVolatile, isNonTemporal,
    795                                  MinAlign(Alignment, IncrementSize));
    796         } else {
    797           // Big endian - avoid unaligned stores.
    798           // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
    799           // Store the top RoundWidth bits.
    800           Hi = DAG.getNode(ISD::SRL, dl, Value.getValueType(), Value,
    801                            DAG.getConstant(ExtraWidth,
    802                                     TLI.getShiftAmountTy(Value.getValueType())));
    803           Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(),
    804                                  RoundVT, isVolatile, isNonTemporal, Alignment);
    805 
    806           // Store the remaining ExtraWidth bits.
    807           IncrementSize = RoundWidth / 8;
    808           Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    809                              DAG.getIntPtrConstant(IncrementSize));
    810           Lo = DAG.getTruncStore(Chain, dl, Value, Ptr,
    811                               ST->getPointerInfo().getWithOffset(IncrementSize),
    812                                  ExtraVT, isVolatile, isNonTemporal,
    813                                  MinAlign(Alignment, IncrementSize));
    814         }
    815 
    816         // The order of the stores doesn't matter.
    817         SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
    818         ReplaceNode(SDValue(Node, 0), Result);
    819       } else {
    820         switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
    821         default: llvm_unreachable("This action is not supported yet!");
    822         case TargetLowering::Legal:
    823           // If this is an unaligned store and the target doesn't support it,
    824           // expand it.
    825           if (!TLI.allowsUnalignedMemoryAccesses(ST->getMemoryVT())) {
    826             Type *Ty = ST->getMemoryVT().getTypeForEVT(*DAG.getContext());
    827             unsigned ABIAlignment= TLI.getTargetData()->getABITypeAlignment(Ty);
    828             if (ST->getAlignment() < ABIAlignment)
    829               ExpandUnalignedStore(cast<StoreSDNode>(Node), DAG, TLI, this);
    830           }
    831           break;
    832         case TargetLowering::Custom: {
    833           SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
    834           if (Res.getNode())
    835             ReplaceNode(SDValue(Node, 0), Res);
    836           return;
    837         }
    838         case TargetLowering::Expand:
    839           assert(!StVT.isVector() &&
    840                  "Vector Stores are handled in LegalizeVectorOps");
    841 
    842           // TRUNCSTORE:i16 i32 -> STORE i16
    843           assert(TLI.isTypeLegal(StVT) &&
    844                  "Do not know how to expand this store!");
    845           Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
    846           SDValue Result =
    847             DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
    848                          isVolatile, isNonTemporal, Alignment);
    849           ReplaceNode(SDValue(Node, 0), Result);
    850           break;
    851         }
    852       }
    853     }
    854 }
    855 
    856 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
    857   LoadSDNode *LD = cast<LoadSDNode>(Node);
    858   SDValue Chain = LD->getChain();  // The chain.
    859   SDValue Ptr = LD->getBasePtr();  // The base pointer.
    860   SDValue Value;                   // The value returned by the load op.
    861   DebugLoc dl = Node->getDebugLoc();
    862 
    863   ISD::LoadExtType ExtType = LD->getExtensionType();
    864   if (ExtType == ISD::NON_EXTLOAD) {
    865     EVT VT = Node->getValueType(0);
    866     SDValue RVal = SDValue(Node, 0);
    867     SDValue RChain = SDValue(Node, 1);
    868 
    869     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
    870     default: llvm_unreachable("This action is not supported yet!");
    871     case TargetLowering::Legal:
    872              // If this is an unaligned load and the target doesn't support it,
    873              // expand it.
    874              if (!TLI.allowsUnalignedMemoryAccesses(LD->getMemoryVT())) {
    875                Type *Ty = LD->getMemoryVT().getTypeForEVT(*DAG.getContext());
    876                unsigned ABIAlignment =
    877                  TLI.getTargetData()->getABITypeAlignment(Ty);
    878                if (LD->getAlignment() < ABIAlignment){
    879                  ExpandUnalignedLoad(cast<LoadSDNode>(Node),
    880                                      DAG, TLI, RVal, RChain);
    881                }
    882              }
    883              break;
    884     case TargetLowering::Custom: {
    885              SDValue Res = TLI.LowerOperation(RVal, DAG);
    886              if (Res.getNode()) {
    887                RVal = Res;
    888                RChain = Res.getValue(1);
    889              }
    890              break;
    891     }
    892     case TargetLowering::Promote: {
    893       // Only promote a load of vector type to another.
    894       assert(VT.isVector() && "Cannot promote this load!");
    895       // Change base type to a different vector type.
    896       EVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
    897 
    898       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
    899                          LD->isVolatile(), LD->isNonTemporal(),
    900                          LD->isInvariant(), LD->getAlignment());
    901       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
    902       RChain = Res.getValue(1);
    903       break;
    904     }
    905     }
    906     if (RChain.getNode() != Node) {
    907       assert(RVal.getNode() != Node && "Load must be completely replaced");
    908       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
    909       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
    910       ReplacedNode(Node);
    911     }
    912     return;
    913   }
    914 
    915   EVT SrcVT = LD->getMemoryVT();
    916   unsigned SrcWidth = SrcVT.getSizeInBits();
    917   unsigned Alignment = LD->getAlignment();
    918   bool isVolatile = LD->isVolatile();
    919   bool isNonTemporal = LD->isNonTemporal();
    920 
    921   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
    922       // Some targets pretend to have an i1 loading operation, and actually
    923       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
    924       // bits are guaranteed to be zero; it helps the optimizers understand
    925       // that these bits are zero.  It is also useful for EXTLOAD, since it
    926       // tells the optimizers that those bits are undefined.  It would be
    927       // nice to have an effective generic way of getting these benefits...
    928       // Until such a way is found, don't insist on promoting i1 here.
    929       (SrcVT != MVT::i1 ||
    930        TLI.getLoadExtAction(ExtType, MVT::i1) == TargetLowering::Promote)) {
    931     // Promote to a byte-sized load if not loading an integral number of
    932     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
    933     unsigned NewWidth = SrcVT.getStoreSizeInBits();
    934     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
    935     SDValue Ch;
    936 
    937     // The extra bits are guaranteed to be zero, since we stored them that
    938     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
    939 
    940     ISD::LoadExtType NewExtType =
    941       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
    942 
    943     SDValue Result =
    944       DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
    945                      Chain, Ptr, LD->getPointerInfo(),
    946                      NVT, isVolatile, isNonTemporal, Alignment);
    947 
    948     Ch = Result.getValue(1); // The chain.
    949 
    950     if (ExtType == ISD::SEXTLOAD)
    951       // Having the top bits zero doesn't help when sign extending.
    952       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
    953                            Result.getValueType(),
    954                            Result, DAG.getValueType(SrcVT));
    955     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
    956       // All the top bits are guaranteed to be zero - inform the optimizers.
    957       Result = DAG.getNode(ISD::AssertZext, dl,
    958                            Result.getValueType(), Result,
    959                            DAG.getValueType(SrcVT));
    960 
    961     Value = Result;
    962     Chain = Ch;
    963   } else if (SrcWidth & (SrcWidth - 1)) {
    964     // If not loading a power-of-2 number of bits, expand as two loads.
    965     assert(!SrcVT.isVector() && "Unsupported extload!");
    966     unsigned RoundWidth = 1 << Log2_32(SrcWidth);
    967     assert(RoundWidth < SrcWidth);
    968     unsigned ExtraWidth = SrcWidth - RoundWidth;
    969     assert(ExtraWidth < RoundWidth);
    970     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
    971            "Load size not an integral number of bytes!");
    972     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
    973     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
    974     SDValue Lo, Hi, Ch;
    975     unsigned IncrementSize;
    976 
    977     if (TLI.isLittleEndian()) {
    978       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
    979       // Load the bottom RoundWidth bits.
    980       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0),
    981                           Chain, Ptr,
    982                           LD->getPointerInfo(), RoundVT, isVolatile,
    983                           isNonTemporal, Alignment);
    984 
    985       // Load the remaining ExtraWidth bits.
    986       IncrementSize = RoundWidth / 8;
    987       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
    988                          DAG.getIntPtrConstant(IncrementSize));
    989       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
    990                           LD->getPointerInfo().getWithOffset(IncrementSize),
    991                           ExtraVT, isVolatile, isNonTemporal,
    992                           MinAlign(Alignment, IncrementSize));
    993 
    994       // Build a factor node to remember that this load is independent of
    995       // the other one.
    996       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
    997                        Hi.getValue(1));
    998 
    999       // Move the top bits to the right place.
   1000       Hi = DAG.getNode(ISD::SHL, dl, Hi.getValueType(), Hi,
   1001                        DAG.getConstant(RoundWidth,
   1002                                        TLI.getShiftAmountTy(Hi.getValueType())));
   1003 
   1004       // Join the hi and lo parts.
   1005       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
   1006     } else {
   1007       // Big endian - avoid unaligned loads.
   1008       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
   1009       // Load the top RoundWidth bits.
   1010       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
   1011                           LD->getPointerInfo(), RoundVT, isVolatile,
   1012                           isNonTemporal, Alignment);
   1013 
   1014       // Load the remaining ExtraWidth bits.
   1015       IncrementSize = RoundWidth / 8;
   1016       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
   1017                          DAG.getIntPtrConstant(IncrementSize));
   1018       Lo = DAG.getExtLoad(ISD::ZEXTLOAD,
   1019                           dl, Node->getValueType(0), Chain, Ptr,
   1020                           LD->getPointerInfo().getWithOffset(IncrementSize),
   1021                           ExtraVT, isVolatile, isNonTemporal,
   1022                           MinAlign(Alignment, IncrementSize));
   1023 
   1024       // Build a factor node to remember that this load is independent of
   1025       // the other one.
   1026       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
   1027                        Hi.getValue(1));
   1028 
   1029       // Move the top bits to the right place.
   1030       Hi = DAG.getNode(ISD::SHL, dl, Hi.getValueType(), Hi,
   1031                        DAG.getConstant(ExtraWidth,
   1032                                        TLI.getShiftAmountTy(Hi.getValueType())));
   1033 
   1034       // Join the hi and lo parts.
   1035       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
   1036     }
   1037 
   1038     Chain = Ch;
   1039   } else {
   1040     bool isCustom = false;
   1041     switch (TLI.getLoadExtAction(ExtType, SrcVT)) {
   1042     default: llvm_unreachable("This action is not supported yet!");
   1043     case TargetLowering::Custom:
   1044              isCustom = true;
   1045              // FALLTHROUGH
   1046     case TargetLowering::Legal: {
   1047              Value = SDValue(Node, 0);
   1048              Chain = SDValue(Node, 1);
   1049 
   1050              if (isCustom) {
   1051                SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
   1052                if (Res.getNode()) {
   1053                  Value = Res;
   1054                  Chain = Res.getValue(1);
   1055                }
   1056              } else {
   1057                // If this is an unaligned load and the target doesn't support it,
   1058                // expand it.
   1059                if (!TLI.allowsUnalignedMemoryAccesses(LD->getMemoryVT())) {
   1060                  Type *Ty =
   1061                    LD->getMemoryVT().getTypeForEVT(*DAG.getContext());
   1062                  unsigned ABIAlignment =
   1063                    TLI.getTargetData()->getABITypeAlignment(Ty);
   1064                  if (LD->getAlignment() < ABIAlignment){
   1065                    ExpandUnalignedLoad(cast<LoadSDNode>(Node),
   1066                                        DAG, TLI, Value, Chain);
   1067                  }
   1068                }
   1069              }
   1070              break;
   1071     }
   1072     case TargetLowering::Expand:
   1073              if (!TLI.isLoadExtLegal(ISD::EXTLOAD, SrcVT) && TLI.isTypeLegal(SrcVT)) {
   1074                SDValue Load = DAG.getLoad(SrcVT, dl, Chain, Ptr,
   1075                                           LD->getPointerInfo(),
   1076                                           LD->isVolatile(), LD->isNonTemporal(),
   1077                                           LD->isInvariant(), LD->getAlignment());
   1078                unsigned ExtendOp;
   1079                switch (ExtType) {
   1080                case ISD::EXTLOAD:
   1081                  ExtendOp = (SrcVT.isFloatingPoint() ?
   1082                              ISD::FP_EXTEND : ISD::ANY_EXTEND);
   1083                  break;
   1084                case ISD::SEXTLOAD: ExtendOp = ISD::SIGN_EXTEND; break;
   1085                case ISD::ZEXTLOAD: ExtendOp = ISD::ZERO_EXTEND; break;
   1086                default: llvm_unreachable("Unexpected extend load type!");
   1087                }
   1088                Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
   1089                Chain = Load.getValue(1);
   1090                break;
   1091              }
   1092 
   1093              assert(!SrcVT.isVector() &&
   1094                     "Vector Loads are handled in LegalizeVectorOps");
   1095 
   1096              // FIXME: This does not work for vectors on most targets.  Sign- and
   1097              // zero-extend operations are currently folded into extending loads,
   1098              // whether they are legal or not, and then we end up here without any
   1099              // support for legalizing them.
   1100              assert(ExtType != ISD::EXTLOAD &&
   1101                     "EXTLOAD should always be supported!");
   1102              // Turn the unsupported load into an EXTLOAD followed by an explicit
   1103              // zero/sign extend inreg.
   1104              SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl, Node->getValueType(0),
   1105                                              Chain, Ptr, LD->getPointerInfo(), SrcVT,
   1106                                              LD->isVolatile(), LD->isNonTemporal(),
   1107                                              LD->getAlignment());
   1108              SDValue ValRes;
   1109              if (ExtType == ISD::SEXTLOAD)
   1110                ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
   1111                                     Result.getValueType(),
   1112                                     Result, DAG.getValueType(SrcVT));
   1113              else
   1114                ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT.getScalarType());
   1115              Value = ValRes;
   1116              Chain = Result.getValue(1);
   1117              break;
   1118     }
   1119   }
   1120 
   1121   // Since loads produce two values, make sure to remember that we legalized
   1122   // both of them.
   1123   if (Chain.getNode() != Node) {
   1124     assert(Value.getNode() != Node && "Load must be completely replaced");
   1125     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
   1126     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
   1127     ReplacedNode(Node);
   1128   }
   1129 }
   1130 
   1131 /// LegalizeOp - Return a legal replacement for the given operation, with
   1132 /// all legal operands.
   1133 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
   1134   if (Node->getOpcode() == ISD::TargetConstant) // Allow illegal target nodes.
   1135     return;
   1136 
   1137   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
   1138     assert(TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
   1139              TargetLowering::TypeLegal &&
   1140            "Unexpected illegal type!");
   1141 
   1142   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i)
   1143     assert((TLI.getTypeAction(*DAG.getContext(),
   1144                               Node->getOperand(i).getValueType()) ==
   1145               TargetLowering::TypeLegal ||
   1146             Node->getOperand(i).getOpcode() == ISD::TargetConstant) &&
   1147            "Unexpected illegal type!");
   1148 
   1149   // Figure out the correct action; the way to query this varies by opcode
   1150   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
   1151   bool SimpleFinishLegalizing = true;
   1152   switch (Node->getOpcode()) {
   1153   case ISD::INTRINSIC_W_CHAIN:
   1154   case ISD::INTRINSIC_WO_CHAIN:
   1155   case ISD::INTRINSIC_VOID:
   1156   case ISD::STACKSAVE:
   1157     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
   1158     break;
   1159   case ISD::VAARG:
   1160     Action = TLI.getOperationAction(Node->getOpcode(),
   1161                                     Node->getValueType(0));
   1162     if (Action != TargetLowering::Promote)
   1163       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
   1164     break;
   1165   case ISD::SINT_TO_FP:
   1166   case ISD::UINT_TO_FP:
   1167   case ISD::EXTRACT_VECTOR_ELT:
   1168     Action = TLI.getOperationAction(Node->getOpcode(),
   1169                                     Node->getOperand(0).getValueType());
   1170     break;
   1171   case ISD::FP_ROUND_INREG:
   1172   case ISD::SIGN_EXTEND_INREG: {
   1173     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
   1174     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
   1175     break;
   1176   }
   1177   case ISD::ATOMIC_STORE: {
   1178     Action = TLI.getOperationAction(Node->getOpcode(),
   1179                                     Node->getOperand(2).getValueType());
   1180     break;
   1181   }
   1182   case ISD::SELECT_CC:
   1183   case ISD::SETCC:
   1184   case ISD::BR_CC: {
   1185     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
   1186                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
   1187     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 : 0;
   1188     EVT OpVT = Node->getOperand(CompareOperand).getValueType();
   1189     ISD::CondCode CCCode =
   1190         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
   1191     Action = TLI.getCondCodeAction(CCCode, OpVT);
   1192     if (Action == TargetLowering::Legal) {
   1193       if (Node->getOpcode() == ISD::SELECT_CC)
   1194         Action = TLI.getOperationAction(Node->getOpcode(),
   1195                                         Node->getValueType(0));
   1196       else
   1197         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
   1198     }
   1199     break;
   1200   }
   1201   case ISD::LOAD:
   1202   case ISD::STORE:
   1203     // FIXME: Model these properly.  LOAD and STORE are complicated, and
   1204     // STORE expects the unlegalized operand in some cases.
   1205     SimpleFinishLegalizing = false;
   1206     break;
   1207   case ISD::CALLSEQ_START:
   1208   case ISD::CALLSEQ_END:
   1209     // FIXME: This shouldn't be necessary.  These nodes have special properties
   1210     // dealing with the recursive nature of legalization.  Removing this
   1211     // special case should be done as part of making LegalizeDAG non-recursive.
   1212     SimpleFinishLegalizing = false;
   1213     break;
   1214   case ISD::EXTRACT_ELEMENT:
   1215   case ISD::FLT_ROUNDS_:
   1216   case ISD::SADDO:
   1217   case ISD::SSUBO:
   1218   case ISD::UADDO:
   1219   case ISD::USUBO:
   1220   case ISD::SMULO:
   1221   case ISD::UMULO:
   1222   case ISD::FPOWI:
   1223   case ISD::MERGE_VALUES:
   1224   case ISD::EH_RETURN:
   1225   case ISD::FRAME_TO_ARGS_OFFSET:
   1226   case ISD::EH_SJLJ_SETJMP:
   1227   case ISD::EH_SJLJ_LONGJMP:
   1228     // These operations lie about being legal: when they claim to be legal,
   1229     // they should actually be expanded.
   1230     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
   1231     if (Action == TargetLowering::Legal)
   1232       Action = TargetLowering::Expand;
   1233     break;
   1234   case ISD::INIT_TRAMPOLINE:
   1235   case ISD::ADJUST_TRAMPOLINE:
   1236   case ISD::FRAMEADDR:
   1237   case ISD::RETURNADDR:
   1238     // These operations lie about being legal: when they claim to be legal,
   1239     // they should actually be custom-lowered.
   1240     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
   1241     if (Action == TargetLowering::Legal)
   1242       Action = TargetLowering::Custom;
   1243     break;
   1244   default:
   1245     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
   1246       Action = TargetLowering::Legal;
   1247     } else {
   1248       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
   1249     }
   1250     break;
   1251   }
   1252 
   1253   if (SimpleFinishLegalizing) {
   1254     SDNode *NewNode = Node;
   1255     switch (Node->getOpcode()) {
   1256     default: break;
   1257     case ISD::SHL:
   1258     case ISD::SRL:
   1259     case ISD::SRA:
   1260     case ISD::ROTL:
   1261     case ISD::ROTR:
   1262       // Legalizing shifts/rotates requires adjusting the shift amount
   1263       // to the appropriate width.
   1264       if (!Node->getOperand(1).getValueType().isVector()) {
   1265         SDValue SAO =
   1266           DAG.getShiftAmountOperand(Node->getOperand(0).getValueType(),
   1267                                     Node->getOperand(1));
   1268         HandleSDNode Handle(SAO);
   1269         LegalizeOp(SAO.getNode());
   1270         NewNode = DAG.UpdateNodeOperands(Node, Node->getOperand(0),
   1271                                          Handle.getValue());
   1272       }
   1273       break;
   1274     case ISD::SRL_PARTS:
   1275     case ISD::SRA_PARTS:
   1276     case ISD::SHL_PARTS:
   1277       // Legalizing shifts/rotates requires adjusting the shift amount
   1278       // to the appropriate width.
   1279       if (!Node->getOperand(2).getValueType().isVector()) {
   1280         SDValue SAO =
   1281           DAG.getShiftAmountOperand(Node->getOperand(0).getValueType(),
   1282                                     Node->getOperand(2));
   1283         HandleSDNode Handle(SAO);
   1284         LegalizeOp(SAO.getNode());
   1285         NewNode = DAG.UpdateNodeOperands(Node, Node->getOperand(0),
   1286                                          Node->getOperand(1),
   1287                                          Handle.getValue());
   1288       }
   1289       break;
   1290     }
   1291 
   1292     if (NewNode != Node) {
   1293       DAG.ReplaceAllUsesWith(Node, NewNode);
   1294       for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
   1295         DAG.TransferDbgValues(SDValue(Node, i), SDValue(NewNode, i));
   1296       ReplacedNode(Node);
   1297       Node = NewNode;
   1298     }
   1299     switch (Action) {
   1300     case TargetLowering::Legal:
   1301       return;
   1302     case TargetLowering::Custom: {
   1303       // FIXME: The handling for custom lowering with multiple results is
   1304       // a complete mess.
   1305       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
   1306       if (Res.getNode()) {
   1307         SmallVector<SDValue, 8> ResultVals;
   1308         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) {
   1309           if (e == 1)
   1310             ResultVals.push_back(Res);
   1311           else
   1312             ResultVals.push_back(Res.getValue(i));
   1313         }
   1314         if (Res.getNode() != Node || Res.getResNo() != 0) {
   1315           DAG.ReplaceAllUsesWith(Node, ResultVals.data());
   1316           for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
   1317             DAG.TransferDbgValues(SDValue(Node, i), ResultVals[i]);
   1318           ReplacedNode(Node);
   1319         }
   1320         return;
   1321       }
   1322     }
   1323       // FALL THROUGH
   1324     case TargetLowering::Expand:
   1325       ExpandNode(Node);
   1326       return;
   1327     case TargetLowering::Promote:
   1328       PromoteNode(Node);
   1329       return;
   1330     }
   1331   }
   1332 
   1333   switch (Node->getOpcode()) {
   1334   default:
   1335 #ifndef NDEBUG
   1336     dbgs() << "NODE: ";
   1337     Node->dump( &DAG);
   1338     dbgs() << "\n";
   1339 #endif
   1340     llvm_unreachable("Do not know how to legalize this operator!");
   1341 
   1342   case ISD::CALLSEQ_START:
   1343   case ISD::CALLSEQ_END:
   1344     break;
   1345   case ISD::LOAD: {
   1346     return LegalizeLoadOps(Node);
   1347   }
   1348   case ISD::STORE: {
   1349     return LegalizeStoreOps(Node);
   1350   }
   1351   }
   1352 }
   1353 
   1354 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
   1355   SDValue Vec = Op.getOperand(0);
   1356   SDValue Idx = Op.getOperand(1);
   1357   DebugLoc dl = Op.getDebugLoc();
   1358   // Store the value to a temporary stack slot, then LOAD the returned part.
   1359   SDValue StackPtr = DAG.CreateStackTemporary(Vec.getValueType());
   1360   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
   1361                             MachinePointerInfo(), false, false, 0);
   1362 
   1363   // Add the offset to the index.
   1364   unsigned EltSize =
   1365       Vec.getValueType().getVectorElementType().getSizeInBits()/8;
   1366   Idx = DAG.getNode(ISD::MUL, dl, Idx.getValueType(), Idx,
   1367                     DAG.getConstant(EltSize, Idx.getValueType()));
   1368 
   1369   if (Idx.getValueType().bitsGT(TLI.getPointerTy()))
   1370     Idx = DAG.getNode(ISD::TRUNCATE, dl, TLI.getPointerTy(), Idx);
   1371   else
   1372     Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx);
   1373 
   1374   StackPtr = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, StackPtr);
   1375 
   1376   if (Op.getValueType().isVector())
   1377     return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr,MachinePointerInfo(),
   1378                        false, false, false, 0);
   1379   return DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
   1380                         MachinePointerInfo(),
   1381                         Vec.getValueType().getVectorElementType(),
   1382                         false, false, 0);
   1383 }
   1384 
   1385 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
   1386   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
   1387 
   1388   SDValue Vec  = Op.getOperand(0);
   1389   SDValue Part = Op.getOperand(1);
   1390   SDValue Idx  = Op.getOperand(2);
   1391   DebugLoc dl  = Op.getDebugLoc();
   1392 
   1393   // Store the value to a temporary stack slot, then LOAD the returned part.
   1394 
   1395   SDValue StackPtr = DAG.CreateStackTemporary(Vec.getValueType());
   1396   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
   1397   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(FI);
   1398 
   1399   // First store the whole vector.
   1400   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo,
   1401                             false, false, 0);
   1402 
   1403   // Then store the inserted part.
   1404 
   1405   // Add the offset to the index.
   1406   unsigned EltSize =
   1407       Vec.getValueType().getVectorElementType().getSizeInBits()/8;
   1408 
   1409   Idx = DAG.getNode(ISD::MUL, dl, Idx.getValueType(), Idx,
   1410                     DAG.getConstant(EltSize, Idx.getValueType()));
   1411 
   1412   if (Idx.getValueType().bitsGT(TLI.getPointerTy()))
   1413     Idx = DAG.getNode(ISD::TRUNCATE, dl, TLI.getPointerTy(), Idx);
   1414   else
   1415     Idx = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Idx);
   1416 
   1417   SDValue SubStackPtr = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
   1418                                     StackPtr);
   1419 
   1420   // Store the subvector.
   1421   Ch = DAG.getStore(DAG.getEntryNode(), dl, Part, SubStackPtr,
   1422                     MachinePointerInfo(), false, false, 0);
   1423 
   1424   // Finally, load the updated vector.
   1425   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo,
   1426                      false, false, false, 0);
   1427 }
   1428 
   1429 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
   1430   // We can't handle this case efficiently.  Allocate a sufficiently
   1431   // aligned object on the stack, store each element into it, then load
   1432   // the result as a vector.
   1433   // Create the stack frame object.
   1434   EVT VT = Node->getValueType(0);
   1435   EVT EltVT = VT.getVectorElementType();
   1436   DebugLoc dl = Node->getDebugLoc();
   1437   SDValue FIPtr = DAG.CreateStackTemporary(VT);
   1438   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
   1439   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(FI);
   1440 
   1441   // Emit a store of each element to the stack slot.
   1442   SmallVector<SDValue, 8> Stores;
   1443   unsigned TypeByteSize = EltVT.getSizeInBits() / 8;
   1444   // Store (in the right endianness) the elements to memory.
   1445   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
   1446     // Ignore undef elements.
   1447     if (Node->getOperand(i).getOpcode() == ISD::UNDEF) continue;
   1448 
   1449     unsigned Offset = TypeByteSize*i;
   1450 
   1451     SDValue Idx = DAG.getConstant(Offset, FIPtr.getValueType());
   1452     Idx = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr, Idx);
   1453 
   1454     // If the destination vector element type is narrower than the source
   1455     // element type, only store the bits necessary.
   1456     if (EltVT.bitsLT(Node->getOperand(i).getValueType().getScalarType())) {
   1457       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
   1458                                          Node->getOperand(i), Idx,
   1459                                          PtrInfo.getWithOffset(Offset),
   1460                                          EltVT, false, false, 0));
   1461     } else
   1462       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl,
   1463                                     Node->getOperand(i), Idx,
   1464                                     PtrInfo.getWithOffset(Offset),
   1465                                     false, false, 0));
   1466   }
   1467 
   1468   SDValue StoreChain;
   1469   if (!Stores.empty())    // Not all undef elements?
   1470     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
   1471                              &Stores[0], Stores.size());
   1472   else
   1473     StoreChain = DAG.getEntryNode();
   1474 
   1475   // Result is a load from the stack slot.
   1476   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo,
   1477                      false, false, false, 0);
   1478 }
   1479 
   1480 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode* Node) {
   1481   DebugLoc dl = Node->getDebugLoc();
   1482   SDValue Tmp1 = Node->getOperand(0);
   1483   SDValue Tmp2 = Node->getOperand(1);
   1484 
   1485   // Get the sign bit of the RHS.  First obtain a value that has the same
   1486   // sign as the sign bit, i.e. negative if and only if the sign bit is 1.
   1487   SDValue SignBit;
   1488   EVT FloatVT = Tmp2.getValueType();
   1489   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), FloatVT.getSizeInBits());
   1490   if (TLI.isTypeLegal(IVT)) {
   1491     // Convert to an integer with the same sign bit.
   1492     SignBit = DAG.getNode(ISD::BITCAST, dl, IVT, Tmp2);
   1493   } else {
   1494     // Store the float to memory, then load the sign part out as an integer.
   1495     MVT LoadTy = TLI.getPointerTy();
   1496     // First create a temporary that is aligned for both the load and store.
   1497     SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
   1498     // Then store the float to it.
   1499     SDValue Ch =
   1500       DAG.getStore(DAG.getEntryNode(), dl, Tmp2, StackPtr, MachinePointerInfo(),
   1501                    false, false, 0);
   1502     if (TLI.isBigEndian()) {
   1503       assert(FloatVT.isByteSized() && "Unsupported floating point type!");
   1504       // Load out a legal integer with the same sign bit as the float.
   1505       SignBit = DAG.getLoad(LoadTy, dl, Ch, StackPtr, MachinePointerInfo(),
   1506                             false, false, false, 0);
   1507     } else { // Little endian
   1508       SDValue LoadPtr = StackPtr;
   1509       // The float may be wider than the integer we are going to load.  Advance
   1510       // the pointer so that the loaded integer will contain the sign bit.
   1511       unsigned Strides = (FloatVT.getSizeInBits()-1)/LoadTy.getSizeInBits();
   1512       unsigned ByteOffset = (Strides * LoadTy.getSizeInBits()) / 8;
   1513       LoadPtr = DAG.getNode(ISD::ADD, dl, LoadPtr.getValueType(),
   1514                             LoadPtr, DAG.getIntPtrConstant(ByteOffset));
   1515       // Load a legal integer containing the sign bit.
   1516       SignBit = DAG.getLoad(LoadTy, dl, Ch, LoadPtr, MachinePointerInfo(),
   1517                             false, false, false, 0);
   1518       // Move the sign bit to the top bit of the loaded integer.
   1519       unsigned BitShift = LoadTy.getSizeInBits() -
   1520         (FloatVT.getSizeInBits() - 8 * ByteOffset);
   1521       assert(BitShift < LoadTy.getSizeInBits() && "Pointer advanced wrong?");
   1522       if (BitShift)
   1523         SignBit = DAG.getNode(ISD::SHL, dl, LoadTy, SignBit,
   1524                               DAG.getConstant(BitShift,
   1525                                  TLI.getShiftAmountTy(SignBit.getValueType())));
   1526     }
   1527   }
   1528   // Now get the sign bit proper, by seeing whether the value is negative.
   1529   SignBit = DAG.getSetCC(dl, TLI.getSetCCResultType(SignBit.getValueType()),
   1530                          SignBit, DAG.getConstant(0, SignBit.getValueType()),
   1531                          ISD::SETLT);
   1532   // Get the absolute value of the result.
   1533   SDValue AbsVal = DAG.getNode(ISD::FABS, dl, Tmp1.getValueType(), Tmp1);
   1534   // Select between the nabs and abs value based on the sign bit of
   1535   // the input.
   1536   return DAG.getNode(ISD::SELECT, dl, AbsVal.getValueType(), SignBit,
   1537                      DAG.getNode(ISD::FNEG, dl, AbsVal.getValueType(), AbsVal),
   1538                      AbsVal);
   1539 }
   1540 
   1541 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
   1542                                            SmallVectorImpl<SDValue> &Results) {
   1543   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
   1544   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
   1545           " not tell us which reg is the stack pointer!");
   1546   DebugLoc dl = Node->getDebugLoc();
   1547   EVT VT = Node->getValueType(0);
   1548   SDValue Tmp1 = SDValue(Node, 0);
   1549   SDValue Tmp2 = SDValue(Node, 1);
   1550   SDValue Tmp3 = Node->getOperand(2);
   1551   SDValue Chain = Tmp1.getOperand(0);
   1552 
   1553   // Chain the dynamic stack allocation so that it doesn't modify the stack
   1554   // pointer when other instructions are using the stack.
   1555   Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(0, true));
   1556 
   1557   SDValue Size  = Tmp2.getOperand(1);
   1558   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
   1559   Chain = SP.getValue(1);
   1560   unsigned Align = cast<ConstantSDNode>(Tmp3)->getZExtValue();
   1561   unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
   1562   if (Align > StackAlign)
   1563     SP = DAG.getNode(ISD::AND, dl, VT, SP,
   1564                       DAG.getConstant(-(uint64_t)Align, VT));
   1565   Tmp1 = DAG.getNode(ISD::SUB, dl, VT, SP, Size);       // Value
   1566   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
   1567 
   1568   Tmp2 = DAG.getCALLSEQ_END(Chain,  DAG.getIntPtrConstant(0, true),
   1569                             DAG.getIntPtrConstant(0, true), SDValue());
   1570 
   1571   Results.push_back(Tmp1);
   1572   Results.push_back(Tmp2);
   1573 }
   1574 
   1575 /// LegalizeSetCCCondCode - Legalize a SETCC with given LHS and RHS and
   1576 /// condition code CC on the current target. This routine expands SETCC with
   1577 /// illegal condition code into AND / OR of multiple SETCC values.
   1578 void SelectionDAGLegalize::LegalizeSetCCCondCode(EVT VT,
   1579                                                  SDValue &LHS, SDValue &RHS,
   1580                                                  SDValue &CC,
   1581                                                  DebugLoc dl) {
   1582   EVT OpVT = LHS.getValueType();
   1583   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
   1584   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
   1585   default: llvm_unreachable("Unknown condition code action!");
   1586   case TargetLowering::Legal:
   1587     // Nothing to do.
   1588     break;
   1589   case TargetLowering::Expand: {
   1590     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
   1591     unsigned Opc = 0;
   1592     switch (CCCode) {
   1593     default: llvm_unreachable("Don't know how to expand this condition!");
   1594     case ISD::SETOEQ: CC1 = ISD::SETEQ; CC2 = ISD::SETO;  Opc = ISD::AND; break;
   1595     case ISD::SETOGT: CC1 = ISD::SETGT; CC2 = ISD::SETO;  Opc = ISD::AND; break;
   1596     case ISD::SETOGE: CC1 = ISD::SETGE; CC2 = ISD::SETO;  Opc = ISD::AND; break;
   1597     case ISD::SETOLT: CC1 = ISD::SETLT; CC2 = ISD::SETO;  Opc = ISD::AND; break;
   1598     case ISD::SETOLE: CC1 = ISD::SETLE; CC2 = ISD::SETO;  Opc = ISD::AND; break;
   1599     case ISD::SETONE: CC1 = ISD::SETNE; CC2 = ISD::SETO;  Opc = ISD::AND; break;
   1600     case ISD::SETUEQ: CC1 = ISD::SETEQ; CC2 = ISD::SETUO; Opc = ISD::OR;  break;
   1601     case ISD::SETUGT: CC1 = ISD::SETGT; CC2 = ISD::SETUO; Opc = ISD::OR;  break;
   1602     case ISD::SETUGE: CC1 = ISD::SETGE; CC2 = ISD::SETUO; Opc = ISD::OR;  break;
   1603     case ISD::SETULT: CC1 = ISD::SETLT; CC2 = ISD::SETUO; Opc = ISD::OR;  break;
   1604     case ISD::SETULE: CC1 = ISD::SETLE; CC2 = ISD::SETUO; Opc = ISD::OR;  break;
   1605     case ISD::SETUNE: CC1 = ISD::SETNE; CC2 = ISD::SETUO; Opc = ISD::OR;  break;
   1606     // FIXME: Implement more expansions.
   1607     }
   1608 
   1609     SDValue SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1);
   1610     SDValue SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2);
   1611     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
   1612     RHS = SDValue();
   1613     CC  = SDValue();
   1614     break;
   1615   }
   1616   }
   1617 }
   1618 
   1619 /// EmitStackConvert - Emit a store/load combination to the stack.  This stores
   1620 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
   1621 /// a load from the stack slot to DestVT, extending it if needed.
   1622 /// The resultant code need not be legal.
   1623 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp,
   1624                                                EVT SlotVT,
   1625                                                EVT DestVT,
   1626                                                DebugLoc dl) {
   1627   // Create the stack frame object.
   1628   unsigned SrcAlign =
   1629     TLI.getTargetData()->getPrefTypeAlignment(SrcOp.getValueType().
   1630                                               getTypeForEVT(*DAG.getContext()));
   1631   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
   1632 
   1633   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
   1634   int SPFI = StackPtrFI->getIndex();
   1635   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
   1636 
   1637   unsigned SrcSize = SrcOp.getValueType().getSizeInBits();
   1638   unsigned SlotSize = SlotVT.getSizeInBits();
   1639   unsigned DestSize = DestVT.getSizeInBits();
   1640   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
   1641   unsigned DestAlign = TLI.getTargetData()->getPrefTypeAlignment(DestType);
   1642 
   1643   // Emit a store to the stack slot.  Use a truncstore if the input value is
   1644   // later than DestVT.
   1645   SDValue Store;
   1646 
   1647   if (SrcSize > SlotSize)
   1648     Store = DAG.getTruncStore(DAG.getEntryNode(), dl, SrcOp, FIPtr,
   1649                               PtrInfo, SlotVT, false, false, SrcAlign);
   1650   else {
   1651     assert(SrcSize == SlotSize && "Invalid store");
   1652     Store = DAG.getStore(DAG.getEntryNode(), dl, SrcOp, FIPtr,
   1653                          PtrInfo, false, false, SrcAlign);
   1654   }
   1655 
   1656   // Result is a load from the stack slot.
   1657   if (SlotSize == DestSize)
   1658     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo,
   1659                        false, false, false, DestAlign);
   1660 
   1661   assert(SlotSize < DestSize && "Unknown extension!");
   1662   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr,
   1663                         PtrInfo, SlotVT, false, false, DestAlign);
   1664 }
   1665 
   1666 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
   1667   DebugLoc dl = Node->getDebugLoc();
   1668   // Create a vector sized/aligned stack slot, store the value to element #0,
   1669   // then load the whole vector back out.
   1670   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
   1671 
   1672   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
   1673   int SPFI = StackPtrFI->getIndex();
   1674 
   1675   SDValue Ch = DAG.getTruncStore(DAG.getEntryNode(), dl, Node->getOperand(0),
   1676                                  StackPtr,
   1677                                  MachinePointerInfo::getFixedStack(SPFI),
   1678                                  Node->getValueType(0).getVectorElementType(),
   1679                                  false, false, 0);
   1680   return DAG.getLoad(Node->getValueType(0), dl, Ch, StackPtr,
   1681                      MachinePointerInfo::getFixedStack(SPFI),
   1682                      false, false, false, 0);
   1683 }
   1684 
   1685 
   1686 /// ExpandBUILD_VECTOR - Expand a BUILD_VECTOR node on targets that don't
   1687 /// support the operation, but do support the resultant vector type.
   1688 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
   1689   unsigned NumElems = Node->getNumOperands();
   1690   SDValue Value1, Value2;
   1691   DebugLoc dl = Node->getDebugLoc();
   1692   EVT VT = Node->getValueType(0);
   1693   EVT OpVT = Node->getOperand(0).getValueType();
   1694   EVT EltVT = VT.getVectorElementType();
   1695 
   1696   // If the only non-undef value is the low element, turn this into a
   1697   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
   1698   bool isOnlyLowElement = true;
   1699   bool MoreThanTwoValues = false;
   1700   bool isConstant = true;
   1701   for (unsigned i = 0; i < NumElems; ++i) {
   1702     SDValue V = Node->getOperand(i);
   1703     if (V.getOpcode() == ISD::UNDEF)
   1704       continue;
   1705     if (i > 0)
   1706       isOnlyLowElement = false;
   1707     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
   1708       isConstant = false;
   1709 
   1710     if (!Value1.getNode()) {
   1711       Value1 = V;
   1712     } else if (!Value2.getNode()) {
   1713       if (V != Value1)
   1714         Value2 = V;
   1715     } else if (V != Value1 && V != Value2) {
   1716       MoreThanTwoValues = true;
   1717     }
   1718   }
   1719 
   1720   if (!Value1.getNode())
   1721     return DAG.getUNDEF(VT);
   1722 
   1723   if (isOnlyLowElement)
   1724     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
   1725 
   1726   // If all elements are constants, create a load from the constant pool.
   1727   if (isConstant) {
   1728     SmallVector<Constant*, 16> CV;
   1729     for (unsigned i = 0, e = NumElems; i != e; ++i) {
   1730       if (ConstantFPSDNode *V =
   1731           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
   1732         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
   1733       } else if (ConstantSDNode *V =
   1734                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
   1735         if (OpVT==EltVT)
   1736           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
   1737         else {
   1738           // If OpVT and EltVT don't match, EltVT is not legal and the
   1739           // element values have been promoted/truncated earlier.  Undo this;
   1740           // we don't want a v16i8 to become a v16i32 for example.
   1741           const ConstantInt *CI = V->getConstantIntValue();
   1742           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
   1743                                         CI->getZExtValue()));
   1744         }
   1745       } else {
   1746         assert(Node->getOperand(i).getOpcode() == ISD::UNDEF);
   1747         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
   1748         CV.push_back(UndefValue::get(OpNTy));
   1749       }
   1750     }
   1751     Constant *CP = ConstantVector::get(CV);
   1752     SDValue CPIdx = DAG.getConstantPool(CP, TLI.getPointerTy());
   1753     unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
   1754     return DAG.getLoad(VT, dl, DAG.getEntryNode(), CPIdx,
   1755                        MachinePointerInfo::getConstantPool(),
   1756                        false, false, false, Alignment);
   1757   }
   1758 
   1759   if (!MoreThanTwoValues) {
   1760     SmallVector<int, 8> ShuffleVec(NumElems, -1);
   1761     for (unsigned i = 0; i < NumElems; ++i) {
   1762       SDValue V = Node->getOperand(i);
   1763       if (V.getOpcode() == ISD::UNDEF)
   1764         continue;
   1765       ShuffleVec[i] = V == Value1 ? 0 : NumElems;
   1766     }
   1767     if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
   1768       // Get the splatted value into the low element of a vector register.
   1769       SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
   1770       SDValue Vec2;
   1771       if (Value2.getNode())
   1772         Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
   1773       else
   1774         Vec2 = DAG.getUNDEF(VT);
   1775 
   1776       // Return shuffle(LowValVec, undef, <0,0,0,0>)
   1777       return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec.data());
   1778     }
   1779   }
   1780 
   1781   // Otherwise, we can't handle this case efficiently.
   1782   return ExpandVectorBuildThroughStack(Node);
   1783 }
   1784 
   1785 // ExpandLibCall - Expand a node into a call to a libcall.  If the result value
   1786 // does not fit into a register, return the lo part and set the hi part to the
   1787 // by-reg argument.  If it does fit into a single register, return the result
   1788 // and leave the Hi part unset.
   1789 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
   1790                                             bool isSigned) {
   1791   TargetLowering::ArgListTy Args;
   1792   TargetLowering::ArgListEntry Entry;
   1793   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
   1794     EVT ArgVT = Node->getOperand(i).getValueType();
   1795     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
   1796     Entry.Node = Node->getOperand(i); Entry.Ty = ArgTy;
   1797     Entry.isSExt = isSigned;
   1798     Entry.isZExt = !isSigned;
   1799     Args.push_back(Entry);
   1800   }
   1801   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   1802                                          TLI.getPointerTy());
   1803 
   1804   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
   1805 
   1806   // By default, the input chain to this libcall is the entry node of the
   1807   // function. If the libcall is going to be emitted as a tail call then
   1808   // TLI.isUsedByReturnOnly will change it to the right chain if the return
   1809   // node which is being folded has a non-entry input chain.
   1810   SDValue InChain = DAG.getEntryNode();
   1811 
   1812   // isTailCall may be true since the callee does not reference caller stack
   1813   // frame. Check if it's in the right position.
   1814   SDValue TCChain = InChain;
   1815   bool isTailCall = isInTailCallPosition(DAG, Node, TCChain, TLI);
   1816   if (isTailCall)
   1817     InChain = TCChain;
   1818 
   1819   TargetLowering::
   1820   CallLoweringInfo CLI(InChain, RetTy, isSigned, !isSigned, false, false,
   1821                     0, TLI.getLibcallCallingConv(LC), isTailCall,
   1822                     /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
   1823                     Callee, Args, DAG, Node->getDebugLoc());
   1824   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
   1825 
   1826 
   1827   if (!CallInfo.second.getNode())
   1828     // It's a tailcall, return the chain (which is the DAG root).
   1829     return DAG.getRoot();
   1830 
   1831   return CallInfo.first;
   1832 }
   1833 
   1834 /// ExpandLibCall - Generate a libcall taking the given operands as arguments
   1835 /// and returning a result of type RetVT.
   1836 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, EVT RetVT,
   1837                                             const SDValue *Ops, unsigned NumOps,
   1838                                             bool isSigned, DebugLoc dl) {
   1839   TargetLowering::ArgListTy Args;
   1840   Args.reserve(NumOps);
   1841 
   1842   TargetLowering::ArgListEntry Entry;
   1843   for (unsigned i = 0; i != NumOps; ++i) {
   1844     Entry.Node = Ops[i];
   1845     Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
   1846     Entry.isSExt = isSigned;
   1847     Entry.isZExt = !isSigned;
   1848     Args.push_back(Entry);
   1849   }
   1850   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   1851                                          TLI.getPointerTy());
   1852 
   1853   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
   1854   TargetLowering::
   1855   CallLoweringInfo CLI(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false,
   1856                        false, 0, TLI.getLibcallCallingConv(LC),
   1857                        /*isTailCall=*/false,
   1858                   /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
   1859                   Callee, Args, DAG, dl);
   1860   std::pair<SDValue,SDValue> CallInfo = TLI.LowerCallTo(CLI);
   1861 
   1862   return CallInfo.first;
   1863 }
   1864 
   1865 // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to
   1866 // ExpandLibCall except that the first operand is the in-chain.
   1867 std::pair<SDValue, SDValue>
   1868 SelectionDAGLegalize::ExpandChainLibCall(RTLIB::Libcall LC,
   1869                                          SDNode *Node,
   1870                                          bool isSigned) {
   1871   SDValue InChain = Node->getOperand(0);
   1872 
   1873   TargetLowering::ArgListTy Args;
   1874   TargetLowering::ArgListEntry Entry;
   1875   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
   1876     EVT ArgVT = Node->getOperand(i).getValueType();
   1877     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
   1878     Entry.Node = Node->getOperand(i);
   1879     Entry.Ty = ArgTy;
   1880     Entry.isSExt = isSigned;
   1881     Entry.isZExt = !isSigned;
   1882     Args.push_back(Entry);
   1883   }
   1884   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   1885                                          TLI.getPointerTy());
   1886 
   1887   Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
   1888   TargetLowering::
   1889   CallLoweringInfo CLI(InChain, RetTy, isSigned, !isSigned, false, false,
   1890                     0, TLI.getLibcallCallingConv(LC), /*isTailCall=*/false,
   1891                     /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
   1892                     Callee, Args, DAG, Node->getDebugLoc());
   1893   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
   1894 
   1895   return CallInfo;
   1896 }
   1897 
   1898 SDValue SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
   1899                                               RTLIB::Libcall Call_F32,
   1900                                               RTLIB::Libcall Call_F64,
   1901                                               RTLIB::Libcall Call_F80,
   1902                                               RTLIB::Libcall Call_PPCF128) {
   1903   RTLIB::Libcall LC;
   1904   switch (Node->getValueType(0).getSimpleVT().SimpleTy) {
   1905   default: llvm_unreachable("Unexpected request for libcall!");
   1906   case MVT::f32: LC = Call_F32; break;
   1907   case MVT::f64: LC = Call_F64; break;
   1908   case MVT::f80: LC = Call_F80; break;
   1909   case MVT::ppcf128: LC = Call_PPCF128; break;
   1910   }
   1911   return ExpandLibCall(LC, Node, false);
   1912 }
   1913 
   1914 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
   1915                                                RTLIB::Libcall Call_I8,
   1916                                                RTLIB::Libcall Call_I16,
   1917                                                RTLIB::Libcall Call_I32,
   1918                                                RTLIB::Libcall Call_I64,
   1919                                                RTLIB::Libcall Call_I128) {
   1920   RTLIB::Libcall LC;
   1921   switch (Node->getValueType(0).getSimpleVT().SimpleTy) {
   1922   default: llvm_unreachable("Unexpected request for libcall!");
   1923   case MVT::i8:   LC = Call_I8; break;
   1924   case MVT::i16:  LC = Call_I16; break;
   1925   case MVT::i32:  LC = Call_I32; break;
   1926   case MVT::i64:  LC = Call_I64; break;
   1927   case MVT::i128: LC = Call_I128; break;
   1928   }
   1929   return ExpandLibCall(LC, Node, isSigned);
   1930 }
   1931 
   1932 /// isDivRemLibcallAvailable - Return true if divmod libcall is available.
   1933 static bool isDivRemLibcallAvailable(SDNode *Node, bool isSigned,
   1934                                      const TargetLowering &TLI) {
   1935   RTLIB::Libcall LC;
   1936   switch (Node->getValueType(0).getSimpleVT().SimpleTy) {
   1937   default: llvm_unreachable("Unexpected request for libcall!");
   1938   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
   1939   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
   1940   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
   1941   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
   1942   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
   1943   }
   1944 
   1945   return TLI.getLibcallName(LC) != 0;
   1946 }
   1947 
   1948 /// useDivRem - Only issue divrem libcall if both quotient and remainder are
   1949 /// needed.
   1950 static bool useDivRem(SDNode *Node, bool isSigned, bool isDIV) {
   1951   // The other use might have been replaced with a divrem already.
   1952   unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
   1953   unsigned OtherOpcode = 0;
   1954   if (isSigned)
   1955     OtherOpcode = isDIV ? ISD::SREM : ISD::SDIV;
   1956   else
   1957     OtherOpcode = isDIV ? ISD::UREM : ISD::UDIV;
   1958 
   1959   SDValue Op0 = Node->getOperand(0);
   1960   SDValue Op1 = Node->getOperand(1);
   1961   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
   1962          UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
   1963     SDNode *User = *UI;
   1964     if (User == Node)
   1965       continue;
   1966     if ((User->getOpcode() == OtherOpcode || User->getOpcode() == DivRemOpc) &&
   1967         User->getOperand(0) == Op0 &&
   1968         User->getOperand(1) == Op1)
   1969       return true;
   1970   }
   1971   return false;
   1972 }
   1973 
   1974 /// ExpandDivRemLibCall - Issue libcalls to __{u}divmod to compute div / rem
   1975 /// pairs.
   1976 void
   1977 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
   1978                                           SmallVectorImpl<SDValue> &Results) {
   1979   unsigned Opcode = Node->getOpcode();
   1980   bool isSigned = Opcode == ISD::SDIVREM;
   1981 
   1982   RTLIB::Libcall LC;
   1983   switch (Node->getValueType(0).getSimpleVT().SimpleTy) {
   1984   default: llvm_unreachable("Unexpected request for libcall!");
   1985   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
   1986   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
   1987   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
   1988   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
   1989   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
   1990   }
   1991 
   1992   // The input chain to this libcall is the entry node of the function.
   1993   // Legalizing the call will automatically add the previous call to the
   1994   // dependence.
   1995   SDValue InChain = DAG.getEntryNode();
   1996 
   1997   EVT RetVT = Node->getValueType(0);
   1998   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
   1999 
   2000   TargetLowering::ArgListTy Args;
   2001   TargetLowering::ArgListEntry Entry;
   2002   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
   2003     EVT ArgVT = Node->getOperand(i).getValueType();
   2004     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
   2005     Entry.Node = Node->getOperand(i); Entry.Ty = ArgTy;
   2006     Entry.isSExt = isSigned;
   2007     Entry.isZExt = !isSigned;
   2008     Args.push_back(Entry);
   2009   }
   2010 
   2011   // Also pass the return address of the remainder.
   2012   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
   2013   Entry.Node = FIPtr;
   2014   Entry.Ty = RetTy->getPointerTo();
   2015   Entry.isSExt = isSigned;
   2016   Entry.isZExt = !isSigned;
   2017   Args.push_back(Entry);
   2018 
   2019   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
   2020                                          TLI.getPointerTy());
   2021 
   2022   DebugLoc dl = Node->getDebugLoc();
   2023   TargetLowering::
   2024   CallLoweringInfo CLI(InChain, RetTy, isSigned, !isSigned, false, false,
   2025                     0, TLI.getLibcallCallingConv(LC), /*isTailCall=*/false,
   2026                     /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
   2027                     Callee, Args, DAG, dl);
   2028   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
   2029 
   2030   // Remainder is loaded back from the stack frame.
   2031   SDValue Rem = DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr,
   2032                             MachinePointerInfo(), false, false, false, 0);
   2033   Results.push_back(CallInfo.first);
   2034   Results.push_back(Rem);
   2035 }
   2036 
   2037 /// ExpandLegalINT_TO_FP - This function is responsible for legalizing a
   2038 /// INT_TO_FP operation of the specified operand when the target requests that
   2039 /// we expand it.  At this point, we know that the result and operand types are
   2040 /// legal for the target.
   2041 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned,
   2042                                                    SDValue Op0,
   2043                                                    EVT DestVT,
   2044                                                    DebugLoc dl) {
   2045   if (Op0.getValueType() == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
   2046     // simple 32-bit [signed|unsigned] integer to float/double expansion
   2047 
   2048     // Get the stack frame index of a 8 byte buffer.
   2049     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
   2050 
   2051     // word offset constant for Hi/Lo address computation
   2052     SDValue WordOff = DAG.getConstant(sizeof(int), TLI.getPointerTy());
   2053     // set up Hi and Lo (into buffer) address based on endian
   2054     SDValue Hi = StackSlot;
   2055     SDValue Lo = DAG.getNode(ISD::ADD, dl,
   2056                              TLI.getPointerTy(), StackSlot, WordOff);
   2057     if (TLI.isLittleEndian())
   2058       std::swap(Hi, Lo);
   2059 
   2060     // if signed map to unsigned space
   2061     SDValue Op0Mapped;
   2062     if (isSigned) {
   2063       // constant used to invert sign bit (signed to unsigned mapping)
   2064       SDValue SignBit = DAG.getConstant(0x80000000u, MVT::i32);
   2065       Op0Mapped = DAG.getNode(ISD::XOR, dl, MVT::i32, Op0, SignBit);
   2066     } else {
   2067       Op0Mapped = Op0;
   2068     }
   2069     // store the lo of the constructed double - based on integer input
   2070     SDValue Store1 = DAG.getStore(DAG.getEntryNode(), dl,
   2071                                   Op0Mapped, Lo, MachinePointerInfo(),
   2072                                   false, false, 0);
   2073     // initial hi portion of constructed double
   2074     SDValue InitialHi = DAG.getConstant(0x43300000u, MVT::i32);
   2075     // store the hi of the constructed double - biased exponent
   2076     SDValue Store2 = DAG.getStore(Store1, dl, InitialHi, Hi,
   2077                                   MachinePointerInfo(),
   2078                                   false, false, 0);
   2079     // load the constructed double
   2080     SDValue Load = DAG.getLoad(MVT::f64, dl, Store2, StackSlot,
   2081                                MachinePointerInfo(), false, false, false, 0);
   2082     // FP constant to bias correct the final result
   2083     SDValue Bias = DAG.getConstantFP(isSigned ?
   2084                                      BitsToDouble(0x4330000080000000ULL) :
   2085                                      BitsToDouble(0x4330000000000000ULL),
   2086                                      MVT::f64);
   2087     // subtract the bias
   2088     SDValue Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
   2089     // final result
   2090     SDValue Result;
   2091     // handle final rounding
   2092     if (DestVT == MVT::f64) {
   2093       // do nothing
   2094       Result = Sub;
   2095     } else if (DestVT.bitsLT(MVT::f64)) {
   2096       Result = DAG.getNode(ISD::FP_ROUND, dl, DestVT, Sub,
   2097                            DAG.getIntPtrConstant(0));
   2098     } else if (DestVT.bitsGT(MVT::f64)) {
   2099       Result = DAG.getNode(ISD::FP_EXTEND, dl, DestVT, Sub);
   2100     }
   2101     return Result;
   2102   }
   2103   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
   2104   // Code below here assumes !isSigned without checking again.
   2105 
   2106   // Implementation of unsigned i64 to f64 following the algorithm in
   2107   // __floatundidf in compiler_rt. This implementation has the advantage
   2108   // of performing rounding correctly, both in the default rounding mode
   2109   // and in all alternate rounding modes.
   2110   // TODO: Generalize this for use with other types.
   2111   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f64) {
   2112     SDValue TwoP52 =
   2113       DAG.getConstant(UINT64_C(0x4330000000000000), MVT::i64);
   2114     SDValue TwoP84PlusTwoP52 =
   2115       DAG.getConstantFP(BitsToDouble(UINT64_C(0x4530000000100000)), MVT::f64);
   2116     SDValue TwoP84 =
   2117       DAG.getConstant(UINT64_C(0x4530000000000000), MVT::i64);
   2118 
   2119     SDValue Lo = DAG.getZeroExtendInReg(Op0, dl, MVT::i32);
   2120     SDValue Hi = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0,
   2121                              DAG.getConstant(32, MVT::i64));
   2122     SDValue LoOr = DAG.getNode(ISD::OR, dl, MVT::i64, Lo, TwoP52);
   2123     SDValue HiOr = DAG.getNode(ISD::OR, dl, MVT::i64, Hi, TwoP84);
   2124     SDValue LoFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, LoOr);
   2125     SDValue HiFlt = DAG.getNode(ISD::BITCAST, dl, MVT::f64, HiOr);
   2126     SDValue HiSub = DAG.getNode(ISD::FSUB, dl, MVT::f64, HiFlt,
   2127                                 TwoP84PlusTwoP52);
   2128     return DAG.getNode(ISD::FADD, dl, MVT::f64, LoFlt, HiSub);
   2129   }
   2130 
   2131   // Implementation of unsigned i64 to f32.
   2132   // TODO: Generalize this for use with other types.
   2133   if (Op0.getValueType() == MVT::i64 && DestVT == MVT::f32) {
   2134     // For unsigned conversions, convert them to signed conversions using the
   2135     // algorithm from the x86_64 __floatundidf in compiler_rt.
   2136     if (!isSigned) {
   2137       SDValue Fast = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Op0);
   2138 
   2139       SDValue ShiftConst =
   2140           DAG.getConstant(1, TLI.getShiftAmountTy(Op0.getValueType()));
   2141       SDValue Shr = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0, ShiftConst);
   2142       SDValue AndConst = DAG.getConstant(1, MVT::i64);
   2143       SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0, AndConst);
   2144       SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And, Shr);
   2145 
   2146       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, Or);
   2147       SDValue Slow = DAG.getNode(ISD::FADD, dl, MVT::f32, SignCvt, SignCvt);
   2148 
   2149       // TODO: This really should be implemented using a branch rather than a
   2150       // select.  We happen to get lucky and machinesink does the right
   2151       // thing most of the time.  This would be a good candidate for a
   2152       //pseudo-op, or, even better, for whole-function isel.
   2153       SDValue SignBitTest = DAG.getSetCC(dl, TLI.getSetCCResultType(MVT::i64),
   2154         Op0, DAG.getConstant(0, MVT::i64), ISD::SETLT);
   2155       return DAG.getNode(ISD::SELECT, dl, MVT::f32, SignBitTest, Slow, Fast);
   2156     }
   2157 
   2158     // Otherwise, implement the fully general conversion.
   2159 
   2160     SDValue And = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
   2161          DAG.getConstant(UINT64_C(0xfffffffffffff800), MVT::i64));
   2162     SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i64, And,
   2163          DAG.getConstant(UINT64_C(0x800), MVT::i64));
   2164     SDValue And2 = DAG.getNode(ISD::AND, dl, MVT::i64, Op0,
   2165          DAG.getConstant(UINT64_C(0x7ff), MVT::i64));
   2166     SDValue Ne = DAG.getSetCC(dl, TLI.getSetCCResultType(MVT::i64),
   2167                    And2, DAG.getConstant(UINT64_C(0), MVT::i64), ISD::SETNE);
   2168     SDValue Sel = DAG.getNode(ISD::SELECT, dl, MVT::i64, Ne, Or, Op0);
   2169     SDValue Ge = DAG.getSetCC(dl, TLI.getSetCCResultType(MVT::i64),
   2170                    Op0, DAG.getConstant(UINT64_C(0x0020000000000000), MVT::i64),
   2171                    ISD::SETUGE);
   2172     SDValue Sel2 = DAG.getNode(ISD::SELECT, dl, MVT::i64, Ge, Sel, Op0);
   2173     EVT SHVT = TLI.getShiftAmountTy(Sel2.getValueType());
   2174 
   2175     SDValue Sh = DAG.getNode(ISD::SRL, dl, MVT::i64, Sel2,
   2176                              DAG.getConstant(32, SHVT));
   2177     SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sh);
   2178     SDValue Fcvt = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Trunc);
   2179     SDValue TwoP32 =
   2180       DAG.getConstantFP(BitsToDouble(UINT64_C(0x41f0000000000000)), MVT::f64);
   2181     SDValue Fmul = DAG.getNode(ISD::FMUL, dl, MVT::f64, TwoP32, Fcvt);
   2182     SDValue Lo = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Sel2);
   2183     SDValue Fcvt2 = DAG.getNode(ISD::UINT_TO_FP, dl, MVT::f64, Lo);
   2184     SDValue Fadd = DAG.getNode(ISD::FADD, dl, MVT::f64, Fmul, Fcvt2);
   2185     return DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Fadd,
   2186                        DAG.getIntPtrConstant(0));
   2187   }
   2188 
   2189   SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
   2190 
   2191   SDValue SignSet = DAG.getSetCC(dl, TLI.getSetCCResultType(Op0.getValueType()),
   2192                                  Op0, DAG.getConstant(0, Op0.getValueType()),
   2193                                  ISD::SETLT);
   2194   SDValue Zero = DAG.getIntPtrConstant(0), Four = DAG.getIntPtrConstant(4);
   2195   SDValue CstOffset = DAG.getNode(ISD::SELECT, dl, Zero.getValueType(),
   2196                                     SignSet, Four, Zero);
   2197 
   2198   // If the sign bit of the integer is set, the large number will be treated
   2199   // as a negative number.  To counteract this, the dynamic code adds an
   2200   // offset depending on the data type.
   2201   uint64_t FF;
   2202   switch (Op0.getValueType().getSimpleVT().SimpleTy) {
   2203   default: llvm_unreachable("Unsupported integer type!");
   2204   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
   2205   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
   2206   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
   2207   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
   2208   }
   2209   if (TLI.isLittleEndian()) FF <<= 32;
   2210   Constant *FudgeFactor = ConstantInt::get(
   2211                                        Type::getInt64Ty(*DAG.getContext()), FF);
   2212 
   2213   SDValue CPIdx = DAG.getConstantPool(FudgeFactor, TLI.getPointerTy());
   2214   unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
   2215   CPIdx = DAG.getNode(ISD::ADD, dl, TLI.getPointerTy(), CPIdx, CstOffset);
   2216   Alignment = std::min(Alignment, 4u);
   2217   SDValue FudgeInReg;
   2218   if (DestVT == MVT::f32)
   2219     FudgeInReg = DAG.getLoad(MVT::f32, dl, DAG.getEntryNode(), CPIdx,
   2220                              MachinePointerInfo::getConstantPool(),
   2221                              false, false, false, Alignment);
   2222   else {
   2223     SDValue Load = DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT,
   2224                                   DAG.getEntryNode(), CPIdx,
   2225                                   MachinePointerInfo::getConstantPool(),
   2226                                   MVT::f32, false, false, Alignment);
   2227     HandleSDNode Handle(Load);
   2228     LegalizeOp(Load.getNode());
   2229     FudgeInReg = Handle.getValue();
   2230   }
   2231 
   2232   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
   2233 }
   2234 
   2235 /// PromoteLegalINT_TO_FP - This function is responsible for legalizing a
   2236 /// *INT_TO_FP operation of the specified operand when the target requests that
   2237 /// we promote it.  At this point, we know that the result and operand types are
   2238 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
   2239 /// operation that takes a larger input.
   2240 SDValue SelectionDAGLegalize::PromoteLegalINT_TO_FP(SDValue LegalOp,
   2241                                                     EVT DestVT,
   2242                                                     bool isSigned,
   2243                                                     DebugLoc dl) {
   2244   // First step, figure out the appropriate *INT_TO_FP operation to use.
   2245   EVT NewInTy = LegalOp.getValueType();
   2246 
   2247   unsigned OpToUse = 0;
   2248 
   2249   // Scan for the appropriate larger type to use.
   2250   while (1) {
   2251     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
   2252     assert(NewInTy.isInteger() && "Ran out of possibilities!");
   2253 
   2254     // If the target supports SINT_TO_FP of this type, use it.
   2255     if (TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, NewInTy)) {
   2256       OpToUse = ISD::SINT_TO_FP;
   2257       break;
   2258     }
   2259     if (isSigned) continue;
   2260 
   2261     // If the target supports UINT_TO_FP of this type, use it.
   2262     if (TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, NewInTy)) {
   2263       OpToUse = ISD::UINT_TO_FP;
   2264       break;
   2265     }
   2266 
   2267     // Otherwise, try a larger type.
   2268   }
   2269 
   2270   // Okay, we found the operation and type to use.  Zero extend our input to the
   2271   // desired type then run the operation on it.
   2272   return DAG.getNode(OpToUse, dl, DestVT,
   2273                      DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
   2274                                  dl, NewInTy, LegalOp));
   2275 }
   2276 
   2277 /// PromoteLegalFP_TO_INT - This function is responsible for legalizing a
   2278 /// FP_TO_*INT operation of the specified operand when the target requests that
   2279 /// we promote it.  At this point, we know that the result and operand types are
   2280 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
   2281 /// operation that returns a larger result.
   2282 SDValue SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDValue LegalOp,
   2283                                                     EVT DestVT,
   2284                                                     bool isSigned,
   2285                                                     DebugLoc dl) {
   2286   // First step, figure out the appropriate FP_TO*INT operation to use.
   2287   EVT NewOutTy = DestVT;
   2288 
   2289   unsigned OpToUse = 0;
   2290 
   2291   // Scan for the appropriate larger type to use.
   2292   while (1) {
   2293     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
   2294     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
   2295 
   2296     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NewOutTy)) {
   2297       OpToUse = ISD::FP_TO_SINT;
   2298       break;
   2299     }
   2300 
   2301     if (TLI.isOperationLegalOrCustom(ISD::FP_TO_UINT, NewOutTy)) {
   2302       OpToUse = ISD::FP_TO_UINT;
   2303       break;
   2304     }
   2305 
   2306     // Otherwise, try a larger type.
   2307   }
   2308 
   2309 
   2310   // Okay, we found the operation and type to use.
   2311   SDValue Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
   2312 
   2313   // Truncate the result of the extended FP_TO_*INT operation to the desired
   2314   // size.
   2315   return DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
   2316 }
   2317 
   2318 /// ExpandBSWAP - Open code the operations for BSWAP of the specified operation.
   2319 ///
   2320 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, DebugLoc dl) {
   2321   EVT VT = Op.getValueType();
   2322   EVT SHVT = TLI.getShiftAmountTy(VT);
   2323   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
   2324   switch (VT.getSimpleVT().SimpleTy) {
   2325   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
   2326   case MVT::i16:
   2327     Tmp2 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2328     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2329     return DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
   2330   case MVT::i32:
   2331     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2332     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2333     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2334     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2335     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3, DAG.getConstant(0xFF0000, VT));
   2336     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, VT));
   2337     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
   2338     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
   2339     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
   2340   case MVT::i64:
   2341     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, SHVT));
   2342     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, SHVT));
   2343     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2344     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2345     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, SHVT));
   2346     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, SHVT));
   2347     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, SHVT));
   2348     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, SHVT));
   2349     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7, DAG.getConstant(255ULL<<48, VT));
   2350     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6, DAG.getConstant(255ULL<<40, VT));
   2351     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5, DAG.getConstant(255ULL<<32, VT));
   2352     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4, DAG.getConstant(255ULL<<24, VT));
   2353     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3, DAG.getConstant(255ULL<<16, VT));
   2354     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(255ULL<<8 , VT));
   2355     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
   2356     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
   2357     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
   2358     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
   2359     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
   2360     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
   2361     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
   2362   }
   2363 }
   2364 
   2365 /// SplatByte - Distribute ByteVal over NumBits bits.
   2366 // FIXME: Move this helper to a common place.
   2367 static APInt SplatByte(unsigned NumBits, uint8_t ByteVal) {
   2368   APInt Val = APInt(NumBits, ByteVal);
   2369   unsigned Shift = 8;
   2370   for (unsigned i = NumBits; i > 8; i >>= 1) {
   2371     Val = (Val << Shift) | Val;
   2372     Shift <<= 1;
   2373   }
   2374   return Val;
   2375 }
   2376 
   2377 /// ExpandBitCount - Expand the specified bitcount instruction into operations.
   2378 ///
   2379 SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
   2380                                              DebugLoc dl) {
   2381   switch (Opc) {
   2382   default: llvm_unreachable("Cannot expand this yet!");
   2383   case ISD::CTPOP: {
   2384     EVT VT = Op.getValueType();
   2385     EVT ShVT = TLI.getShiftAmountTy(VT);
   2386     unsigned Len = VT.getSizeInBits();
   2387 
   2388     assert(VT.isInteger() && Len <= 128 && Len % 8 == 0 &&
   2389            "CTPOP not implemented for this type.");
   2390 
   2391     // This is the "best" algorithm from
   2392     // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
   2393 
   2394     SDValue Mask55 = DAG.getConstant(SplatByte(Len, 0x55), VT);
   2395     SDValue Mask33 = DAG.getConstant(SplatByte(Len, 0x33), VT);
   2396     SDValue Mask0F = DAG.getConstant(SplatByte(Len, 0x0F), VT);
   2397     SDValue Mask01 = DAG.getConstant(SplatByte(Len, 0x01), VT);
   2398 
   2399     // v = v - ((v >> 1) & 0x55555555...)
   2400     Op = DAG.getNode(ISD::SUB, dl, VT, Op,
   2401                      DAG.getNode(ISD::AND, dl, VT,
   2402                                  DAG.getNode(ISD::SRL, dl, VT, Op,
   2403                                              DAG.getConstant(1, ShVT)),
   2404                                  Mask55));
   2405     // v = (v & 0x33333333...) + ((v >> 2) & 0x33333333...)
   2406     Op = DAG.getNode(ISD::ADD, dl, VT,
   2407                      DAG.getNode(ISD::AND, dl, VT, Op, Mask33),
   2408                      DAG.getNode(ISD::AND, dl, VT,
   2409                                  DAG.getNode(ISD::SRL, dl, VT, Op,
   2410                                              DAG.getConstant(2, ShVT)),
   2411                                  Mask33));
   2412     // v = (v + (v >> 4)) & 0x0F0F0F0F...
   2413     Op = DAG.getNode(ISD::AND, dl, VT,
   2414                      DAG.getNode(ISD::ADD, dl, VT, Op,
   2415                                  DAG.getNode(ISD::SRL, dl, VT, Op,
   2416                                              DAG.getConstant(4, ShVT))),
   2417                      Mask0F);
   2418     // v = (v * 0x01010101...) >> (Len - 8)
   2419     Op = DAG.getNode(ISD::SRL, dl, VT,
   2420                      DAG.getNode(ISD::MUL, dl, VT, Op, Mask01),
   2421                      DAG.getConstant(Len - 8, ShVT));
   2422 
   2423     return Op;
   2424   }
   2425   case ISD::CTLZ_ZERO_UNDEF:
   2426     // This trivially expands to CTLZ.
   2427     return DAG.getNode(ISD::CTLZ, dl, Op.getValueType(), Op);
   2428   case ISD::CTLZ: {
   2429     // for now, we do this:
   2430     // x = x | (x >> 1);
   2431     // x = x | (x >> 2);
   2432     // ...
   2433     // x = x | (x >>16);
   2434     // x = x | (x >>32); // for 64-bit input
   2435     // return popcount(~x);
   2436     //
   2437     // but see also: http://www.hackersdelight.org/HDcode/nlz.cc
   2438     EVT VT = Op.getValueType();
   2439     EVT ShVT = TLI.getShiftAmountTy(VT);
   2440     unsigned len = VT.getSizeInBits();
   2441     for (unsigned i = 0; (1U << i) <= (len / 2); ++i) {
   2442       SDValue Tmp3 = DAG.getConstant(1ULL << i, ShVT);
   2443       Op = DAG.getNode(ISD::OR, dl, VT, Op,
   2444                        DAG.getNode(ISD::SRL, dl, VT, Op, Tmp3));
   2445     }
   2446     Op = DAG.getNOT(dl, Op, VT);
   2447     return DAG.getNode(ISD::CTPOP, dl, VT, Op);
   2448   }
   2449   case ISD::CTTZ_ZERO_UNDEF:
   2450     // This trivially expands to CTTZ.
   2451     return DAG.getNode(ISD::CTTZ, dl, Op.getValueType(), Op);
   2452   case ISD::CTTZ: {
   2453     // for now, we use: { return popcount(~x & (x - 1)); }
   2454     // unless the target has ctlz but not ctpop, in which case we use:
   2455     // { return 32 - nlz(~x & (x-1)); }
   2456     // see also http://www.hackersdelight.org/HDcode/ntz.cc
   2457     EVT VT = Op.getValueType();
   2458     SDValue Tmp3 = DAG.getNode(ISD::AND, dl, VT,
   2459                                DAG.getNOT(dl, Op, VT),
   2460                                DAG.getNode(ISD::SUB, dl, VT, Op,
   2461                                            DAG.getConstant(1, VT)));
   2462     // If ISD::CTLZ is legal and CTPOP isn't, then do that instead.
   2463     if (!TLI.isOperationLegalOrCustom(ISD::CTPOP, VT) &&
   2464         TLI.isOperationLegalOrCustom(ISD::CTLZ, VT))
   2465       return DAG.getNode(ISD::SUB, dl, VT,
   2466                          DAG.getConstant(VT.getSizeInBits(), VT),
   2467                          DAG.getNode(ISD::CTLZ, dl, VT, Tmp3));
   2468     return DAG.getNode(ISD::CTPOP, dl, VT, Tmp3);
   2469   }
   2470   }
   2471 }
   2472 
   2473 std::pair <SDValue, SDValue> SelectionDAGLegalize::ExpandAtomic(SDNode *Node) {
   2474   unsigned Opc = Node->getOpcode();
   2475   MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
   2476   RTLIB::Libcall LC;
   2477 
   2478   switch (Opc) {
   2479   default:
   2480     llvm_unreachable("Unhandled atomic intrinsic Expand!");
   2481   case ISD::ATOMIC_SWAP:
   2482     switch (VT.SimpleTy) {
   2483     default: llvm_unreachable("Unexpected value type for atomic!");
   2484     case MVT::i8:  LC = RTLIB::SYNC_LOCK_TEST_AND_SET_1; break;
   2485     case MVT::i16: LC = RTLIB::SYNC_LOCK_TEST_AND_SET_2; break;
   2486     case MVT::i32: LC = RTLIB::SYNC_LOCK_TEST_AND_SET_4; break;
   2487     case MVT::i64: LC = RTLIB::SYNC_LOCK_TEST_AND_SET_8; break;
   2488     }
   2489     break;
   2490   case ISD::ATOMIC_CMP_SWAP:
   2491     switch (VT.SimpleTy) {
   2492     default: llvm_unreachable("Unexpected value type for atomic!");
   2493     case MVT::i8:  LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_1; break;
   2494     case MVT::i16: LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_2; break;
   2495     case MVT::i32: LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_4; break;
   2496     case MVT::i64: LC = RTLIB::SYNC_VAL_COMPARE_AND_SWAP_8; break;
   2497     }
   2498     break;
   2499   case ISD::ATOMIC_LOAD_ADD:
   2500     switch (VT.SimpleTy) {
   2501     default: llvm_unreachable("Unexpected value type for atomic!");
   2502     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_ADD_1; break;
   2503     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_ADD_2; break;
   2504     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_ADD_4; break;
   2505     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_ADD_8; break;
   2506     }
   2507     break;
   2508   case ISD::ATOMIC_LOAD_SUB:
   2509     switch (VT.SimpleTy) {
   2510     default: llvm_unreachable("Unexpected value type for atomic!");
   2511     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_SUB_1; break;
   2512     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_SUB_2; break;
   2513     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_SUB_4; break;
   2514     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_SUB_8; break;
   2515     }
   2516     break;
   2517   case ISD::ATOMIC_LOAD_AND:
   2518     switch (VT.SimpleTy) {
   2519     default: llvm_unreachable("Unexpected value type for atomic!");
   2520     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_AND_1; break;
   2521     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_AND_2; break;
   2522     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_AND_4; break;
   2523     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_AND_8; break;
   2524     }
   2525     break;
   2526   case ISD::ATOMIC_LOAD_OR:
   2527     switch (VT.SimpleTy) {
   2528     default: llvm_unreachable("Unexpected value type for atomic!");
   2529     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_OR_1; break;
   2530     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_OR_2; break;
   2531     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_OR_4; break;
   2532     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_OR_8; break;
   2533     }
   2534     break;
   2535   case ISD::ATOMIC_LOAD_XOR:
   2536     switch (VT.SimpleTy) {
   2537     default: llvm_unreachable("Unexpected value type for atomic!");
   2538     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_XOR_1; break;
   2539     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_XOR_2; break;
   2540     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_XOR_4; break;
   2541     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_XOR_8; break;
   2542     }
   2543     break;
   2544   case ISD::ATOMIC_LOAD_NAND:
   2545     switch (VT.SimpleTy) {
   2546     default: llvm_unreachable("Unexpected value type for atomic!");
   2547     case MVT::i8:  LC = RTLIB::SYNC_FETCH_AND_NAND_1; break;
   2548     case MVT::i16: LC = RTLIB::SYNC_FETCH_AND_NAND_2; break;
   2549     case MVT::i32: LC = RTLIB::SYNC_FETCH_AND_NAND_4; break;
   2550     case MVT::i64: LC = RTLIB::SYNC_FETCH_AND_NAND_8; break;
   2551     }
   2552     break;
   2553   }
   2554 
   2555   return ExpandChainLibCall(LC, Node, false);
   2556 }
   2557 
   2558 void SelectionDAGLegalize::ExpandNode(SDNode *Node) {
   2559   SmallVector<SDValue, 8> Results;
   2560   DebugLoc dl = Node->getDebugLoc();
   2561   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
   2562   switch (Node->getOpcode()) {
   2563   case ISD::CTPOP:
   2564   case ISD::CTLZ:
   2565   case ISD::CTLZ_ZERO_UNDEF:
   2566   case ISD::CTTZ:
   2567   case ISD::CTTZ_ZERO_UNDEF:
   2568     Tmp1 = ExpandBitCount(Node->getOpcode(), Node->getOperand(0), dl);
   2569     Results.push_back(Tmp1);
   2570     break;
   2571   case ISD::BSWAP:
   2572     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
   2573     break;
   2574   case ISD::FRAMEADDR:
   2575   case ISD::RETURNADDR:
   2576   case ISD::FRAME_TO_ARGS_OFFSET:
   2577     Results.push_back(DAG.getConstant(0, Node->getValueType(0)));
   2578     break;
   2579   case ISD::FLT_ROUNDS_:
   2580     Results.push_back(DAG.getConstant(1, Node->getValueType(0)));
   2581     break;
   2582   case ISD::EH_RETURN:
   2583   case ISD::EH_LABEL:
   2584   case ISD::PREFETCH:
   2585   case ISD::VAEND:
   2586   case ISD::EH_SJLJ_LONGJMP:
   2587     // If the target didn't expand these, there's nothing to do, so just
   2588     // preserve the chain and be done.
   2589     Results.push_back(Node->getOperand(0));
   2590     break;
   2591   case ISD::EH_SJLJ_SETJMP:
   2592     // If the target didn't expand this, just return 'zero' and preserve the
   2593     // chain.
   2594     Results.push_back(DAG.getConstant(0, MVT::i32));
   2595     Results.push_back(Node->getOperand(0));
   2596     break;
   2597   case ISD::ATOMIC_FENCE:
   2598   case ISD::MEMBARRIER: {
   2599     // If the target didn't lower this, lower it to '__sync_synchronize()' call
   2600     // FIXME: handle "fence singlethread" more efficiently.
   2601     TargetLowering::ArgListTy Args;
   2602     TargetLowering::
   2603     CallLoweringInfo CLI(Node->getOperand(0),
   2604                          Type::getVoidTy(*DAG.getContext()),
   2605                       false, false, false, false, 0, CallingConv::C,
   2606                       /*isTailCall=*/false,
   2607                       /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
   2608                       DAG.getExternalSymbol("__sync_synchronize",
   2609                                             TLI.getPointerTy()),
   2610                       Args, DAG, dl);
   2611     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
   2612 
   2613     Results.push_back(CallResult.second);
   2614     break;
   2615   }
   2616   case ISD::ATOMIC_LOAD: {
   2617     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
   2618     SDValue Zero = DAG.getConstant(0, Node->getValueType(0));
   2619     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_CMP_SWAP, dl,
   2620                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
   2621                                  Node->getOperand(0),
   2622                                  Node->getOperand(1), Zero, Zero,
   2623                                  cast<AtomicSDNode>(Node)->getMemOperand(),
   2624                                  cast<AtomicSDNode>(Node)->getOrdering(),
   2625                                  cast<AtomicSDNode>(Node)->getSynchScope());
   2626     Results.push_back(Swap.getValue(0));
   2627     Results.push_back(Swap.getValue(1));
   2628     break;
   2629   }
   2630   case ISD::ATOMIC_STORE: {
   2631     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
   2632     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
   2633                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
   2634                                  Node->getOperand(0),
   2635                                  Node->getOperand(1), Node->getOperand(2),
   2636                                  cast<AtomicSDNode>(Node)->getMemOperand(),
   2637                                  cast<AtomicSDNode>(Node)->getOrdering(),
   2638                                  cast<AtomicSDNode>(Node)->getSynchScope());
   2639     Results.push_back(Swap.getValue(1));
   2640     break;
   2641   }
   2642   // By default, atomic intrinsics are marked Legal and lowered. Targets
   2643   // which don't support them directly, however, may want libcalls, in which
   2644   // case they mark them Expand, and we get here.
   2645   case ISD::ATOMIC_SWAP:
   2646   case ISD::ATOMIC_LOAD_ADD:
   2647   case ISD::ATOMIC_LOAD_SUB:
   2648   case ISD::ATOMIC_LOAD_AND:
   2649   case ISD::ATOMIC_LOAD_OR:
   2650   case ISD::ATOMIC_LOAD_XOR:
   2651   case ISD::ATOMIC_LOAD_NAND:
   2652   case ISD::ATOMIC_LOAD_MIN:
   2653   case ISD::ATOMIC_LOAD_MAX:
   2654   case ISD::ATOMIC_LOAD_UMIN:
   2655   case ISD::ATOMIC_LOAD_UMAX:
   2656   case ISD::ATOMIC_CMP_SWAP: {
   2657     std::pair<SDValue, SDValue> Tmp = ExpandAtomic(Node);
   2658     Results.push_back(Tmp.first);
   2659     Results.push_back(Tmp.second);
   2660     break;
   2661   }
   2662   case ISD::DYNAMIC_STACKALLOC:
   2663     ExpandDYNAMIC_STACKALLOC(Node, Results);
   2664     break;
   2665   case ISD::MERGE_VALUES:
   2666     for (unsigned i = 0; i < Node->getNumValues(); i++)
   2667       Results.push_back(Node->getOperand(i));
   2668     break;
   2669   case ISD::UNDEF: {
   2670     EVT VT = Node->getValueType(0);
   2671     if (VT.isInteger())
   2672       Results.push_back(DAG.getConstant(0, VT));
   2673     else {
   2674       assert(VT.isFloatingPoint() && "Unknown value type!");
   2675       Results.push_back(DAG.getConstantFP(0, VT));
   2676     }
   2677     break;
   2678   }
   2679   case ISD::TRAP: {
   2680     // If this operation is not supported, lower it to 'abort()' call
   2681     TargetLowering::ArgListTy Args;
   2682     TargetLowering::
   2683     CallLoweringInfo CLI(Node->getOperand(0),
   2684                          Type::getVoidTy(*DAG.getContext()),
   2685                       false, false, false, false, 0, CallingConv::C,
   2686                       /*isTailCall=*/false,
   2687                       /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
   2688                       DAG.getExternalSymbol("abort", TLI.getPointerTy()),
   2689                       Args, DAG, dl);
   2690     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
   2691 
   2692     Results.push_back(CallResult.second);
   2693     break;
   2694   }
   2695   case ISD::FP_ROUND:
   2696   case ISD::BITCAST:
   2697     Tmp1 = EmitStackConvert(Node->getOperand(0), Node->getValueType(0),
   2698                             Node->getValueType(0), dl);
   2699     Results.push_back(Tmp1);
   2700     break;
   2701   case ISD::FP_EXTEND:
   2702     Tmp1 = EmitStackConvert(Node->getOperand(0),
   2703                             Node->getOperand(0).getValueType(),
   2704                             Node->getValueType(0), dl);
   2705     Results.push_back(Tmp1);
   2706     break;
   2707   case ISD::SIGN_EXTEND_INREG: {
   2708     // NOTE: we could fall back on load/store here too for targets without
   2709     // SAR.  However, it is doubtful that any exist.
   2710     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
   2711     EVT VT = Node->getValueType(0);
   2712     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT);
   2713     if (VT.isVector())
   2714       ShiftAmountTy = VT;
   2715     unsigned BitsDiff = VT.getScalarType().getSizeInBits() -
   2716                         ExtraVT.getScalarType().getSizeInBits();
   2717     SDValue ShiftCst = DAG.getConstant(BitsDiff, ShiftAmountTy);
   2718     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
   2719                        Node->getOperand(0), ShiftCst);
   2720     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
   2721     Results.push_back(Tmp1);
   2722     break;
   2723   }
   2724   case ISD::FP_ROUND_INREG: {
   2725     // The only way we can lower this is to turn it into a TRUNCSTORE,
   2726     // EXTLOAD pair, targeting a temporary location (a stack slot).
   2727 
   2728     // NOTE: there is a choice here between constantly creating new stack
   2729     // slots and always reusing the same one.  We currently always create
   2730     // new ones, as reuse may inhibit scheduling.
   2731     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
   2732     Tmp1 = EmitStackConvert(Node->getOperand(0), ExtraVT,
   2733                             Node->getValueType(0), dl);
   2734     Results.push_back(Tmp1);
   2735     break;
   2736   }
   2737   case ISD::SINT_TO_FP:
   2738   case ISD::UINT_TO_FP:
   2739     Tmp1 = ExpandLegalINT_TO_FP(Node->getOpcode() == ISD::SINT_TO_FP,
   2740                                 Node->getOperand(0), Node->getValueType(0), dl);
   2741     Results.push_back(Tmp1);
   2742     break;
   2743   case ISD::FP_TO_UINT: {
   2744     SDValue True, False;
   2745     EVT VT =  Node->getOperand(0).getValueType();
   2746     EVT NVT = Node->getValueType(0);
   2747     APFloat apf(APInt::getNullValue(VT.getSizeInBits()));
   2748     APInt x = APInt::getSignBit(NVT.getSizeInBits());
   2749     (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
   2750     Tmp1 = DAG.getConstantFP(apf, VT);
   2751     Tmp2 = DAG.getSetCC(dl, TLI.getSetCCResultType(VT),
   2752                         Node->getOperand(0),
   2753                         Tmp1, ISD::SETLT);
   2754     True = DAG.getNode(ISD::FP_TO_SINT, dl, NVT, Node->getOperand(0));
   2755     False = DAG.getNode(ISD::FP_TO_SINT, dl, NVT,
   2756                         DAG.getNode(ISD::FSUB, dl, VT,
   2757                                     Node->getOperand(0), Tmp1));
   2758     False = DAG.getNode(ISD::XOR, dl, NVT, False,
   2759                         DAG.getConstant(x, NVT));
   2760     Tmp1 = DAG.getNode(ISD::SELECT, dl, NVT, Tmp2, True, False);
   2761     Results.push_back(Tmp1);
   2762     break;
   2763   }
   2764   case ISD::VAARG: {
   2765     const Value *V = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
   2766     EVT VT = Node->getValueType(0);
   2767     Tmp1 = Node->getOperand(0);
   2768     Tmp2 = Node->getOperand(1);
   2769     unsigned Align = Node->getConstantOperandVal(3);
   2770 
   2771     SDValue VAListLoad = DAG.getLoad(TLI.getPointerTy(), dl, Tmp1, Tmp2,
   2772                                      MachinePointerInfo(V),
   2773                                      false, false, false, 0);
   2774     SDValue VAList = VAListLoad;
   2775 
   2776     if (Align > TLI.getMinStackArgumentAlignment()) {
   2777       assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2");
   2778 
   2779       VAList = DAG.getNode(ISD::ADD, dl, TLI.getPointerTy(), VAList,
   2780                            DAG.getConstant(Align - 1,
   2781                                            TLI.getPointerTy()));
   2782 
   2783       VAList = DAG.getNode(ISD::AND, dl, TLI.getPointerTy(), VAList,
   2784                            DAG.getConstant(-(int64_t)Align,
   2785                                            TLI.getPointerTy()));
   2786     }
   2787 
   2788     // Increment the pointer, VAList, to the next vaarg
   2789     Tmp3 = DAG.getNode(ISD::ADD, dl, TLI.getPointerTy(), VAList,
   2790                        DAG.getConstant(TLI.getTargetData()->
   2791                           getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext())),
   2792                                        TLI.getPointerTy()));
   2793     // Store the incremented VAList to the legalized pointer
   2794     Tmp3 = DAG.getStore(VAListLoad.getValue(1), dl, Tmp3, Tmp2,
   2795                         MachinePointerInfo(V), false, false, 0);
   2796     // Load the actual argument out of the pointer VAList
   2797     Results.push_back(DAG.getLoad(VT, dl, Tmp3, VAList, MachinePointerInfo(),
   2798                                   false, false, false, 0));
   2799     Results.push_back(Results[0].getValue(1));
   2800     break;
   2801   }
   2802   case ISD::VACOPY: {
   2803     // This defaults to loading a pointer from the input and storing it to the
   2804     // output, returning the chain.
   2805     const Value *VD = cast<SrcValueSDNode>(Node->getOperand(3))->getValue();
   2806     const Value *VS = cast<SrcValueSDNode>(Node->getOperand(4))->getValue();
   2807     Tmp1 = DAG.getLoad(TLI.getPointerTy(), dl, Node->getOperand(0),
   2808                        Node->getOperand(2), MachinePointerInfo(VS),
   2809                        false, false, false, 0);
   2810     Tmp1 = DAG.getStore(Tmp1.getValue(1), dl, Tmp1, Node->getOperand(1),
   2811                         MachinePointerInfo(VD), false, false, 0);
   2812     Results.push_back(Tmp1);
   2813     break;
   2814   }
   2815   case ISD::EXTRACT_VECTOR_ELT:
   2816     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
   2817       // This must be an access of the only element.  Return it.
   2818       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
   2819                          Node->getOperand(0));
   2820     else
   2821       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
   2822     Results.push_back(Tmp1);
   2823     break;
   2824   case ISD::EXTRACT_SUBVECTOR:
   2825     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
   2826     break;
   2827   case ISD::INSERT_SUBVECTOR:
   2828     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
   2829     break;
   2830   case ISD::CONCAT_VECTORS: {
   2831     Results.push_back(ExpandVectorBuildThroughStack(Node));
   2832     break;
   2833   }
   2834   case ISD::SCALAR_TO_VECTOR:
   2835     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
   2836     break;
   2837   case ISD::INSERT_VECTOR_ELT:
   2838     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
   2839                                               Node->getOperand(1),
   2840                                               Node->getOperand(2), dl));
   2841     break;
   2842   case ISD::VECTOR_SHUFFLE: {
   2843     SmallVector<int, 32> NewMask;
   2844     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
   2845 
   2846     EVT VT = Node->getValueType(0);
   2847     EVT EltVT = VT.getVectorElementType();
   2848     SDValue Op0 = Node->getOperand(0);
   2849     SDValue Op1 = Node->getOperand(1);
   2850     if (!TLI.isTypeLegal(EltVT)) {
   2851 
   2852       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
   2853 
   2854       // BUILD_VECTOR operands are allowed to be wider than the element type.
   2855       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept it
   2856       if (NewEltVT.bitsLT(EltVT)) {
   2857 
   2858         // Convert shuffle node.
   2859         // If original node was v4i64 and the new EltVT is i32,
   2860         // cast operands to v8i32 and re-build the mask.
   2861 
   2862         // Calculate new VT, the size of the new VT should be equal to original.
   2863         EVT NewVT = EVT::getVectorVT(*DAG.getContext(), NewEltVT,
   2864                                       VT.getSizeInBits()/NewEltVT.getSizeInBits());
   2865         assert(NewVT.bitsEq(VT));
   2866 
   2867         // cast operands to new VT
   2868         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
   2869         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
   2870 
   2871         // Convert the shuffle mask
   2872         unsigned int factor = NewVT.getVectorNumElements()/VT.getVectorNumElements();
   2873 
   2874         // EltVT gets smaller
   2875         assert(factor > 0);
   2876 
   2877         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
   2878           if (Mask[i] < 0) {
   2879             for (unsigned fi = 0; fi < factor; ++fi)
   2880               NewMask.push_back(Mask[i]);
   2881           }
   2882           else {
   2883             for (unsigned fi = 0; fi < factor; ++fi)
   2884               NewMask.push_back(Mask[i]*factor+fi);
   2885           }
   2886         }
   2887         Mask = NewMask;
   2888         VT = NewVT;
   2889       }
   2890       EltVT = NewEltVT;
   2891     }
   2892     unsigned NumElems = VT.getVectorNumElements();
   2893     SmallVector<SDValue, 16> Ops;
   2894     for (unsigned i = 0; i != NumElems; ++i) {
   2895       if (Mask[i] < 0) {
   2896         Ops.push_back(DAG.getUNDEF(EltVT));
   2897         continue;
   2898       }
   2899       unsigned Idx = Mask[i];
   2900       if (Idx < NumElems)
   2901         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
   2902                                   Op0,
   2903                                   DAG.getIntPtrConstant(Idx)));
   2904       else
   2905         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
   2906                                   Op1,
   2907                                   DAG.getIntPtrConstant(Idx - NumElems)));
   2908     }
   2909 
   2910     Tmp1 = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, &Ops[0], Ops.size());
   2911     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
   2912     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
   2913     Results.push_back(Tmp1);
   2914     break;
   2915   }
   2916   case ISD::EXTRACT_ELEMENT: {
   2917     EVT OpTy = Node->getOperand(0).getValueType();
   2918     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
   2919       // 1 -> Hi
   2920       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
   2921                          DAG.getConstant(OpTy.getSizeInBits()/2,
   2922                     TLI.getShiftAmountTy(Node->getOperand(0).getValueType())));
   2923       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
   2924     } else {
   2925       // 0 -> Lo
   2926       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
   2927                          Node->getOperand(0));
   2928     }
   2929     Results.push_back(Tmp1);
   2930     break;
   2931   }
   2932   case ISD::STACKSAVE:
   2933     // Expand to CopyFromReg if the target set
   2934     // StackPointerRegisterToSaveRestore.
   2935     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
   2936       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
   2937                                            Node->getValueType(0)));
   2938       Results.push_back(Results[0].getValue(1));
   2939     } else {
   2940       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
   2941       Results.push_back(Node->getOperand(0));
   2942     }
   2943     break;
   2944   case ISD::STACKRESTORE:
   2945     // Expand to CopyToReg if the target set
   2946     // StackPointerRegisterToSaveRestore.
   2947     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
   2948       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
   2949                                          Node->getOperand(1)));
   2950     } else {
   2951       Results.push_back(Node->getOperand(0));
   2952     }
   2953     break;
   2954   case ISD::FCOPYSIGN:
   2955     Results.push_back(ExpandFCOPYSIGN(Node));
   2956     break;
   2957   case ISD::FNEG:
   2958     // Expand Y = FNEG(X) ->  Y = SUB -0.0, X
   2959     Tmp1 = DAG.getConstantFP(-0.0, Node->getValueType(0));
   2960     Tmp1 = DAG.getNode(ISD::FSUB, dl, Node->getValueType(0), Tmp1,
   2961                        Node->getOperand(0));
   2962     Results.push_back(Tmp1);
   2963     break;
   2964   case ISD::FABS: {
   2965     // Expand Y = FABS(X) -> Y = (X >u 0.0) ? X : fneg(X).
   2966     EVT VT = Node->getValueType(0);
   2967     Tmp1 = Node->getOperand(0);
   2968     Tmp2 = DAG.getConstantFP(0.0, VT);
   2969     Tmp2 = DAG.getSetCC(dl, TLI.getSetCCResultType(Tmp1.getValueType()),
   2970                         Tmp1, Tmp2, ISD::SETUGT);
   2971     Tmp3 = DAG.getNode(ISD::FNEG, dl, VT, Tmp1);
   2972     Tmp1 = DAG.getNode(ISD::SELECT, dl, VT, Tmp2, Tmp1, Tmp3);
   2973     Results.push_back(Tmp1);
   2974     break;
   2975   }
   2976   case ISD::FSQRT:
   2977     Results.push_back(ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
   2978                                       RTLIB::SQRT_F80, RTLIB::SQRT_PPCF128));
   2979     break;
   2980   case ISD::FSIN:
   2981     Results.push_back(ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
   2982                                       RTLIB::SIN_F80, RTLIB::SIN_PPCF128));
   2983     break;
   2984   case ISD::FCOS:
   2985     Results.push_back(ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
   2986                                       RTLIB::COS_F80, RTLIB::COS_PPCF128));
   2987     break;
   2988   case ISD::FLOG:
   2989     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64,
   2990                                       RTLIB::LOG_F80, RTLIB::LOG_PPCF128));
   2991     break;
   2992   case ISD::FLOG2:
   2993     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64,
   2994                                       RTLIB::LOG2_F80, RTLIB::LOG2_PPCF128));
   2995     break;
   2996   case ISD::FLOG10:
   2997     Results.push_back(ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64,
   2998                                       RTLIB::LOG10_F80, RTLIB::LOG10_PPCF128));
   2999     break;
   3000   case ISD::FEXP:
   3001     Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64,
   3002                                       RTLIB::EXP_F80, RTLIB::EXP_PPCF128));
   3003     break;
   3004   case ISD::FEXP2:
   3005     Results.push_back(ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64,
   3006                                       RTLIB::EXP2_F80, RTLIB::EXP2_PPCF128));
   3007     break;
   3008   case ISD::FTRUNC:
   3009     Results.push_back(ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
   3010                                       RTLIB::TRUNC_F80, RTLIB::TRUNC_PPCF128));
   3011     break;
   3012   case ISD::FFLOOR:
   3013     Results.push_back(ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
   3014                                       RTLIB::FLOOR_F80, RTLIB::FLOOR_PPCF128));
   3015     break;
   3016   case ISD::FCEIL:
   3017     Results.push_back(ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
   3018                                       RTLIB::CEIL_F80, RTLIB::CEIL_PPCF128));
   3019     break;
   3020   case ISD::FRINT:
   3021     Results.push_back(ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
   3022                                       RTLIB::RINT_F80, RTLIB::RINT_PPCF128));
   3023     break;
   3024   case ISD::FNEARBYINT:
   3025     Results.push_back(ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
   3026                                       RTLIB::NEARBYINT_F64,
   3027                                       RTLIB::NEARBYINT_F80,
   3028                                       RTLIB::NEARBYINT_PPCF128));
   3029     break;
   3030   case ISD::FPOWI:
   3031     Results.push_back(ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
   3032                                       RTLIB::POWI_F80, RTLIB::POWI_PPCF128));
   3033     break;
   3034   case ISD::FPOW:
   3035     Results.push_back(ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64,
   3036                                       RTLIB::POW_F80, RTLIB::POW_PPCF128));
   3037     break;
   3038   case ISD::FDIV:
   3039     Results.push_back(ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
   3040                                       RTLIB::DIV_F80, RTLIB::DIV_PPCF128));
   3041     break;
   3042   case ISD::FREM:
   3043     Results.push_back(ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
   3044                                       RTLIB::REM_F80, RTLIB::REM_PPCF128));
   3045     break;
   3046   case ISD::FMA:
   3047     Results.push_back(ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
   3048                                       RTLIB::FMA_F80, RTLIB::FMA_PPCF128));
   3049     break;
   3050   case ISD::FP16_TO_FP32:
   3051     Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
   3052     break;
   3053   case ISD::FP32_TO_FP16:
   3054     Results.push_back(ExpandLibCall(RTLIB::FPROUND_F32_F16, Node, false));
   3055     break;
   3056   case ISD::ConstantFP: {
   3057     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
   3058     // Check to see if this FP immediate is already legal.
   3059     // If this is a legal constant, turn it into a TargetConstantFP node.
   3060     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0)))
   3061       Results.push_back(ExpandConstantFP(CFP, true));
   3062     break;
   3063   }
   3064   case ISD::EHSELECTION: {
   3065     unsigned Reg = TLI.getExceptionSelectorRegister();
   3066     assert(Reg && "Can't expand to unknown register!");
   3067     Results.push_back(DAG.getCopyFromReg(Node->getOperand(1), dl, Reg,
   3068                                          Node->getValueType(0)));
   3069     Results.push_back(Results[0].getValue(1));
   3070     break;
   3071   }
   3072   case ISD::EXCEPTIONADDR: {
   3073     unsigned Reg = TLI.getExceptionPointerRegister();
   3074     assert(Reg && "Can't expand to unknown register!");
   3075     Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, Reg,
   3076                                          Node->getValueType(0)));
   3077     Results.push_back(Results[0].getValue(1));
   3078     break;
   3079   }
   3080   case ISD::FSUB: {
   3081     EVT VT = Node->getValueType(0);
   3082     assert(TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
   3083            TLI.isOperationLegalOrCustom(ISD::FNEG, VT) &&
   3084            "Don't know how to expand this FP subtraction!");
   3085     Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
   3086     Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1);
   3087     Results.push_back(Tmp1);
   3088     break;
   3089   }
   3090   case ISD::SUB: {
   3091     EVT VT = Node->getValueType(0);
   3092     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
   3093            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
   3094            "Don't know how to expand this subtraction!");
   3095     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
   3096                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), VT));
   3097     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, VT));
   3098     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
   3099     break;
   3100   }
   3101   case ISD::UREM:
   3102   case ISD::SREM: {
   3103     EVT VT = Node->getValueType(0);
   3104     SDVTList VTs = DAG.getVTList(VT, VT);
   3105     bool isSigned = Node->getOpcode() == ISD::SREM;
   3106     unsigned DivOpc = isSigned ? ISD::SDIV : ISD::UDIV;
   3107     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
   3108     Tmp2 = Node->getOperand(0);
   3109     Tmp3 = Node->getOperand(1);
   3110     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT) ||
   3111         (isDivRemLibcallAvailable(Node, isSigned, TLI) &&
   3112          useDivRem(Node, isSigned, false))) {
   3113       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Tmp2, Tmp3).getValue(1);
   3114     } else if (TLI.isOperationLegalOrCustom(DivOpc, VT)) {
   3115       // X % Y -> X-X/Y*Y
   3116       Tmp1 = DAG.getNode(DivOpc, dl, VT, Tmp2, Tmp3);
   3117       Tmp1 = DAG.getNode(ISD::MUL, dl, VT, Tmp1, Tmp3);
   3118       Tmp1 = DAG.getNode(ISD::SUB, dl, VT, Tmp2, Tmp1);
   3119     } else if (isSigned)
   3120       Tmp1 = ExpandIntLibCall(Node, true,
   3121                               RTLIB::SREM_I8,
   3122                               RTLIB::SREM_I16, RTLIB::SREM_I32,
   3123                               RTLIB::SREM_I64, RTLIB::SREM_I128);
   3124     else
   3125       Tmp1 = ExpandIntLibCall(Node, false,
   3126                               RTLIB::UREM_I8,
   3127                               RTLIB::UREM_I16, RTLIB::UREM_I32,
   3128                               RTLIB::UREM_I64, RTLIB::UREM_I128);
   3129     Results.push_back(Tmp1);
   3130     break;
   3131   }
   3132   case ISD::UDIV:
   3133   case ISD::SDIV: {
   3134     bool isSigned = Node->getOpcode() == ISD::SDIV;
   3135     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
   3136     EVT VT = Node->getValueType(0);
   3137     SDVTList VTs = DAG.getVTList(VT, VT);
   3138     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT) ||
   3139         (isDivRemLibcallAvailable(Node, isSigned, TLI) &&
   3140          useDivRem(Node, isSigned, true)))
   3141       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
   3142                          Node->getOperand(1));
   3143     else if (isSigned)
   3144       Tmp1 = ExpandIntLibCall(Node, true,
   3145                               RTLIB::SDIV_I8,
   3146                               RTLIB::SDIV_I16, RTLIB::SDIV_I32,
   3147                               RTLIB::SDIV_I64, RTLIB::SDIV_I128);
   3148     else
   3149       Tmp1 = ExpandIntLibCall(Node, false,
   3150                               RTLIB::UDIV_I8,
   3151                               RTLIB::UDIV_I16, RTLIB::UDIV_I32,
   3152                               RTLIB::UDIV_I64, RTLIB::UDIV_I128);
   3153     Results.push_back(Tmp1);
   3154     break;
   3155   }
   3156   case ISD::MULHU:
   3157   case ISD::MULHS: {
   3158     unsigned ExpandOpcode = Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI :
   3159                                                               ISD::SMUL_LOHI;
   3160     EVT VT = Node->getValueType(0);
   3161     SDVTList VTs = DAG.getVTList(VT, VT);
   3162     assert(TLI.isOperationLegalOrCustom(ExpandOpcode, VT) &&
   3163            "If this wasn't legal, it shouldn't have been created!");
   3164     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
   3165                        Node->getOperand(1));
   3166     Results.push_back(Tmp1.getValue(1));
   3167     break;
   3168   }
   3169   case ISD::SDIVREM:
   3170   case ISD::UDIVREM:
   3171     // Expand into divrem libcall
   3172     ExpandDivRemLibCall(Node, Results);
   3173     break;
   3174   case ISD::MUL: {
   3175     EVT VT = Node->getValueType(0);
   3176     SDVTList VTs = DAG.getVTList(VT, VT);
   3177     // See if multiply or divide can be lowered using two-result operations.
   3178     // We just need the low half of the multiply; try both the signed
   3179     // and unsigned forms. If the target supports both SMUL_LOHI and
   3180     // UMUL_LOHI, form a preference by checking which forms of plain
   3181     // MULH it supports.
   3182     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
   3183     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
   3184     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
   3185     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
   3186     unsigned OpToUse = 0;
   3187     if (HasSMUL_LOHI && !HasMULHS) {
   3188       OpToUse = ISD::SMUL_LOHI;
   3189     } else if (HasUMUL_LOHI && !HasMULHU) {
   3190       OpToUse = ISD::UMUL_LOHI;
   3191     } else if (HasSMUL_LOHI) {
   3192       OpToUse = ISD::SMUL_LOHI;
   3193     } else if (HasUMUL_LOHI) {
   3194       OpToUse = ISD::UMUL_LOHI;
   3195     }
   3196     if (OpToUse) {
   3197       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
   3198                                     Node->getOperand(1)));
   3199       break;
   3200     }
   3201     Tmp1 = ExpandIntLibCall(Node, false,
   3202                             RTLIB::MUL_I8,
   3203                             RTLIB::MUL_I16, RTLIB::MUL_I32,
   3204                             RTLIB::MUL_I64, RTLIB::MUL_I128);
   3205     Results.push_back(Tmp1);
   3206     break;
   3207   }
   3208   case ISD::SADDO:
   3209   case ISD::SSUBO: {
   3210     SDValue LHS = Node->getOperand(0);
   3211     SDValue RHS = Node->getOperand(1);
   3212     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::SADDO ?
   3213                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
   3214                               LHS, RHS);
   3215     Results.push_back(Sum);
   3216     EVT OType = Node->getValueType(1);
   3217 
   3218     SDValue Zero = DAG.getConstant(0, LHS.getValueType());
   3219 
   3220     //   LHSSign -> LHS >= 0
   3221     //   RHSSign -> RHS >= 0
   3222     //   SumSign -> Sum >= 0
   3223     //
   3224     //   Add:
   3225     //   Overflow -> (LHSSign == RHSSign) && (LHSSign != SumSign)
   3226     //   Sub:
   3227     //   Overflow -> (LHSSign != RHSSign) && (LHSSign != SumSign)
   3228     //
   3229     SDValue LHSSign = DAG.getSetCC(dl, OType, LHS, Zero, ISD::SETGE);
   3230     SDValue RHSSign = DAG.getSetCC(dl, OType, RHS, Zero, ISD::SETGE);
   3231     SDValue SignsMatch = DAG.getSetCC(dl, OType, LHSSign, RHSSign,
   3232                                       Node->getOpcode() == ISD::SADDO ?
   3233                                       ISD::SETEQ : ISD::SETNE);
   3234 
   3235     SDValue SumSign = DAG.getSetCC(dl, OType, Sum, Zero, ISD::SETGE);
   3236     SDValue SumSignNE = DAG.getSetCC(dl, OType, LHSSign, SumSign, ISD::SETNE);
   3237 
   3238     SDValue Cmp = DAG.getNode(ISD::AND, dl, OType, SignsMatch, SumSignNE);
   3239     Results.push_back(Cmp);
   3240     break;
   3241   }
   3242   case ISD::UADDO:
   3243   case ISD::USUBO: {
   3244     SDValue LHS = Node->getOperand(0);
   3245     SDValue RHS = Node->getOperand(1);
   3246     SDValue Sum = DAG.getNode(Node->getOpcode() == ISD::UADDO ?
   3247                               ISD::ADD : ISD::SUB, dl, LHS.getValueType(),
   3248                               LHS, RHS);
   3249     Results.push_back(Sum);
   3250     Results.push_back(DAG.getSetCC(dl, Node->getValueType(1), Sum, LHS,
   3251                                    Node->getOpcode () == ISD::UADDO ?
   3252                                    ISD::SETULT : ISD::SETUGT));
   3253     break;
   3254   }
   3255   case ISD::UMULO:
   3256   case ISD::SMULO: {
   3257     EVT VT = Node->getValueType(0);
   3258     EVT WideVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits() * 2);
   3259     SDValue LHS = Node->getOperand(0);
   3260     SDValue RHS = Node->getOperand(1);
   3261     SDValue BottomHalf;
   3262     SDValue TopHalf;
   3263     static const unsigned Ops[2][3] =
   3264         { { ISD::MULHU, ISD::UMUL_LOHI, ISD::ZERO_EXTEND },
   3265           { ISD::MULHS, ISD::SMUL_LOHI, ISD::SIGN_EXTEND }};
   3266     bool isSigned = Node->getOpcode() == ISD::SMULO;
   3267     if (TLI.isOperationLegalOrCustom(Ops[isSigned][0], VT)) {
   3268       BottomHalf = DAG.getNode(ISD::MUL, dl, VT, LHS, RHS);
   3269       TopHalf = DAG.getNode(Ops[isSigned][0], dl, VT, LHS, RHS);
   3270     } else if (TLI.isOperationLegalOrCustom(Ops[isSigned][1], VT)) {
   3271       BottomHalf = DAG.getNode(Ops[isSigned][1], dl, DAG.getVTList(VT, VT), LHS,
   3272                                RHS);
   3273       TopHalf = BottomHalf.getValue(1);
   3274     } else if (TLI.isTypeLegal(EVT::getIntegerVT(*DAG.getContext(),
   3275                                                  VT.getSizeInBits() * 2))) {
   3276       LHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, LHS);
   3277       RHS = DAG.getNode(Ops[isSigned][2], dl, WideVT, RHS);
   3278       Tmp1 = DAG.getNode(ISD::MUL, dl, WideVT, LHS, RHS);
   3279       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
   3280                                DAG.getIntPtrConstant(0));
   3281       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Tmp1,
   3282                             DAG.getIntPtrConstant(1));
   3283     } else {
   3284       // We can fall back to a libcall with an illegal type for the MUL if we
   3285       // have a libcall big enough.
   3286       // Also, we can fall back to a division in some cases, but that's a big
   3287       // performance hit in the general case.
   3288       RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
   3289       if (WideVT == MVT::i16)
   3290         LC = RTLIB::MUL_I16;
   3291       else if (WideVT == MVT::i32)
   3292         LC = RTLIB::MUL_I32;
   3293       else if (WideVT == MVT::i64)
   3294         LC = RTLIB::MUL_I64;
   3295       else if (WideVT == MVT::i128)
   3296         LC = RTLIB::MUL_I128;
   3297       assert(LC != RTLIB::UNKNOWN_LIBCALL && "Cannot expand this operation!");
   3298 
   3299       // The high part is obtained by SRA'ing all but one of the bits of low
   3300       // part.
   3301       unsigned LoSize = VT.getSizeInBits();
   3302       SDValue HiLHS = DAG.getNode(ISD::SRA, dl, VT, RHS,
   3303                                 DAG.getConstant(LoSize-1, TLI.getPointerTy()));
   3304       SDValue HiRHS = DAG.getNode(ISD::SRA, dl, VT, LHS,
   3305                                 DAG.getConstant(LoSize-1, TLI.getPointerTy()));
   3306 
   3307       // Here we're passing the 2 arguments explicitly as 4 arguments that are
   3308       // pre-lowered to the correct types. This all depends upon WideVT not
   3309       // being a legal type for the architecture and thus has to be split to
   3310       // two arguments.
   3311       SDValue Args[] = { LHS, HiLHS, RHS, HiRHS };
   3312       SDValue Ret = ExpandLibCall(LC, WideVT, Args, 4, isSigned, dl);
   3313       BottomHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Ret,
   3314                                DAG.getIntPtrConstant(0));
   3315       TopHalf = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, VT, Ret,
   3316                             DAG.getIntPtrConstant(1));
   3317       // Ret is a node with an illegal type. Because such things are not
   3318       // generally permitted during this phase of legalization, delete the
   3319       // node. The above EXTRACT_ELEMENT nodes should have been folded.
   3320       DAG.DeleteNode(Ret.getNode());
   3321     }
   3322 
   3323     if (isSigned) {
   3324       Tmp1 = DAG.getConstant(VT.getSizeInBits() - 1,
   3325                              TLI.getShiftAmountTy(BottomHalf.getValueType()));
   3326       Tmp1 = DAG.getNode(ISD::SRA, dl, VT, BottomHalf, Tmp1);
   3327       TopHalf = DAG.getSetCC(dl, TLI.getSetCCResultType(VT), TopHalf, Tmp1,
   3328                              ISD::SETNE);
   3329     } else {
   3330       TopHalf = DAG.getSetCC(dl, TLI.getSetCCResultType(VT), TopHalf,
   3331                              DAG.getConstant(0, VT), ISD::SETNE);
   3332     }
   3333     Results.push_back(BottomHalf);
   3334     Results.push_back(TopHalf);
   3335     break;
   3336   }
   3337   case ISD::BUILD_PAIR: {
   3338     EVT PairTy = Node->getValueType(0);
   3339     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
   3340     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
   3341     Tmp2 = DAG.getNode(ISD::SHL, dl, PairTy, Tmp2,
   3342                        DAG.getConstant(PairTy.getSizeInBits()/2,
   3343                                        TLI.getShiftAmountTy(PairTy)));
   3344     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
   3345     break;
   3346   }
   3347   case ISD::SELECT:
   3348     Tmp1 = Node->getOperand(0);
   3349     Tmp2 = Node->getOperand(1);
   3350     Tmp3 = Node->getOperand(2);
   3351     if (Tmp1.getOpcode() == ISD::SETCC) {
   3352       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
   3353                              Tmp2, Tmp3,
   3354                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
   3355     } else {
   3356       Tmp1 = DAG.getSelectCC(dl, Tmp1,
   3357                              DAG.getConstant(0, Tmp1.getValueType()),
   3358                              Tmp2, Tmp3, ISD::SETNE);
   3359     }
   3360     Results.push_back(Tmp1);
   3361     break;
   3362   case ISD::BR_JT: {
   3363     SDValue Chain = Node->getOperand(0);
   3364     SDValue Table = Node->getOperand(1);
   3365     SDValue Index = Node->getOperand(2);
   3366 
   3367     EVT PTy = TLI.getPointerTy();
   3368 
   3369     const TargetData &TD = *TLI.getTargetData();
   3370     unsigned EntrySize =
   3371       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
   3372 
   3373     Index = DAG.getNode(ISD::MUL, dl, PTy,
   3374                         Index, DAG.getConstant(EntrySize, PTy));
   3375     SDValue Addr = DAG.getNode(ISD::ADD, dl, PTy, Index, Table);
   3376 
   3377     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
   3378     SDValue LD = DAG.getExtLoad(ISD::SEXTLOAD, dl, PTy, Chain, Addr,
   3379                                 MachinePointerInfo::getJumpTable(), MemVT,
   3380                                 false, false, 0);
   3381     Addr = LD;
   3382     if (TM.getRelocationModel() == Reloc::PIC_) {
   3383       // For PIC, the sequence is:
   3384       // BRIND(load(Jumptable + index) + RelocBase)
   3385       // RelocBase can be JumpTable, GOT or some sort of global base.
   3386       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
   3387                           TLI.getPICJumpTableRelocBase(Table, DAG));
   3388     }
   3389     Tmp1 = DAG.getNode(ISD::BRIND, dl, MVT::Other, LD.getValue(1), Addr);
   3390     Results.push_back(Tmp1);
   3391     break;
   3392   }
   3393   case ISD::BRCOND:
   3394     // Expand brcond's setcc into its constituent parts and create a BR_CC
   3395     // Node.
   3396     Tmp1 = Node->getOperand(0);
   3397     Tmp2 = Node->getOperand(1);
   3398     if (Tmp2.getOpcode() == ISD::SETCC) {
   3399       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
   3400                          Tmp1, Tmp2.getOperand(2),
   3401                          Tmp2.getOperand(0), Tmp2.getOperand(1),
   3402                          Node->getOperand(2));
   3403     } else {
   3404       // We test only the i1 bit.  Skip the AND if UNDEF.
   3405       Tmp3 = (Tmp2.getOpcode() == ISD::UNDEF) ? Tmp2 :
   3406         DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
   3407                     DAG.getConstant(1, Tmp2.getValueType()));
   3408       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
   3409                          DAG.getCondCode(ISD::SETNE), Tmp3,
   3410                          DAG.getConstant(0, Tmp3.getValueType()),
   3411                          Node->getOperand(2));
   3412     }
   3413     Results.push_back(Tmp1);
   3414     break;
   3415   case ISD::SETCC: {
   3416     Tmp1 = Node->getOperand(0);
   3417     Tmp2 = Node->getOperand(1);
   3418     Tmp3 = Node->getOperand(2);
   3419     LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2, Tmp3, dl);
   3420 
   3421     // If we expanded the SETCC into an AND/OR, return the new node
   3422     if (Tmp2.getNode() == 0) {
   3423       Results.push_back(Tmp1);
   3424       break;
   3425     }
   3426 
   3427     // Otherwise, SETCC for the given comparison type must be completely
   3428     // illegal; expand it into a SELECT_CC.
   3429     EVT VT = Node->getValueType(0);
   3430     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
   3431                        DAG.getConstant(1, VT), DAG.getConstant(0, VT), Tmp3);
   3432     Results.push_back(Tmp1);
   3433     break;
   3434   }
   3435   case ISD::SELECT_CC: {
   3436     Tmp1 = Node->getOperand(0);   // LHS
   3437     Tmp2 = Node->getOperand(1);   // RHS
   3438     Tmp3 = Node->getOperand(2);   // True
   3439     Tmp4 = Node->getOperand(3);   // False
   3440     SDValue CC = Node->getOperand(4);
   3441 
   3442     LegalizeSetCCCondCode(TLI.getSetCCResultType(Tmp1.getValueType()),
   3443                           Tmp1, Tmp2, CC, dl);
   3444 
   3445     assert(!Tmp2.getNode() && "Can't legalize SELECT_CC with legal condition!");
   3446     Tmp2 = DAG.getConstant(0, Tmp1.getValueType());
   3447     CC = DAG.getCondCode(ISD::SETNE);
   3448     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1, Tmp2,
   3449                        Tmp3, Tmp4, CC);
   3450     Results.push_back(Tmp1);
   3451     break;
   3452   }
   3453   case ISD::BR_CC: {
   3454     Tmp1 = Node->getOperand(0);              // Chain
   3455     Tmp2 = Node->getOperand(2);              // LHS
   3456     Tmp3 = Node->getOperand(3);              // RHS
   3457     Tmp4 = Node->getOperand(1);              // CC
   3458 
   3459     LegalizeSetCCCondCode(TLI.getSetCCResultType(Tmp2.getValueType()),
   3460                           Tmp2, Tmp3, Tmp4, dl);
   3461 
   3462     assert(!Tmp3.getNode() && "Can't legalize BR_CC with legal condition!");
   3463     Tmp3 = DAG.getConstant(0, Tmp2.getValueType());
   3464     Tmp4 = DAG.getCondCode(ISD::SETNE);
   3465     Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4, Tmp2,
   3466                        Tmp3, Node->getOperand(4));
   3467     Results.push_back(Tmp1);
   3468     break;
   3469   }
   3470   case ISD::BUILD_VECTOR:
   3471     Results.push_back(ExpandBUILD_VECTOR(Node));
   3472     break;
   3473   case ISD::SRA:
   3474   case ISD::SRL:
   3475   case ISD::SHL: {
   3476     // Scalarize vector SRA/SRL/SHL.
   3477     EVT VT = Node->getValueType(0);
   3478     assert(VT.isVector() && "Unable to legalize non-vector shift");
   3479     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
   3480     unsigned NumElem = VT.getVectorNumElements();
   3481 
   3482     SmallVector<SDValue, 8> Scalars;
   3483     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
   3484       SDValue Ex = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
   3485                                VT.getScalarType(),
   3486                                Node->getOperand(0), DAG.getIntPtrConstant(Idx));
   3487       SDValue Sh = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
   3488                                VT.getScalarType(),
   3489                                Node->getOperand(1), DAG.getIntPtrConstant(Idx));
   3490       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
   3491                                     VT.getScalarType(), Ex, Sh));
   3492     }
   3493     SDValue Result =
   3494       DAG.getNode(ISD::BUILD_VECTOR, dl, Node->getValueType(0),
   3495                   &Scalars[0], Scalars.size());
   3496     ReplaceNode(SDValue(Node, 0), Result);
   3497     break;
   3498   }
   3499   case ISD::GLOBAL_OFFSET_TABLE:
   3500   case ISD::GlobalAddress:
   3501   case ISD::GlobalTLSAddress:
   3502   case ISD::ExternalSymbol:
   3503   case ISD::ConstantPool:
   3504   case ISD::JumpTable:
   3505   case ISD::INTRINSIC_W_CHAIN:
   3506   case ISD::INTRINSIC_WO_CHAIN:
   3507   case ISD::INTRINSIC_VOID:
   3508     // FIXME: Custom lowering for these operations shouldn't return null!
   3509     break;
   3510   }
   3511 
   3512   // Replace the original node with the legalized result.
   3513   if (!Results.empty())
   3514     ReplaceNode(Node, Results.data());
   3515 }
   3516 
   3517 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
   3518   SmallVector<SDValue, 8> Results;
   3519   EVT OVT = Node->getValueType(0);
   3520   if (Node->getOpcode() == ISD::UINT_TO_FP ||
   3521       Node->getOpcode() == ISD::SINT_TO_FP ||
   3522       Node->getOpcode() == ISD::SETCC) {
   3523     OVT = Node->getOperand(0).getValueType();
   3524   }
   3525   EVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
   3526   DebugLoc dl = Node->getDebugLoc();
   3527   SDValue Tmp1, Tmp2, Tmp3;
   3528   switch (Node->getOpcode()) {
   3529   case ISD::CTTZ:
   3530   case ISD::CTTZ_ZERO_UNDEF:
   3531   case ISD::CTLZ:
   3532   case ISD::CTLZ_ZERO_UNDEF:
   3533   case ISD::CTPOP:
   3534     // Zero extend the argument.
   3535     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
   3536     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
   3537     // already the correct result.
   3538     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
   3539     if (Node->getOpcode() == ISD::CTTZ) {
   3540       // FIXME: This should set a bit in the zero extended value instead.
   3541       Tmp2 = DAG.getSetCC(dl, TLI.getSetCCResultType(NVT),
   3542                           Tmp1, DAG.getConstant(NVT.getSizeInBits(), NVT),
   3543                           ISD::SETEQ);
   3544       Tmp1 = DAG.getNode(ISD::SELECT, dl, NVT, Tmp2,
   3545                           DAG.getConstant(OVT.getSizeInBits(), NVT), Tmp1);
   3546     } else if (Node->getOpcode() == ISD::CTLZ ||
   3547                Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
   3548       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
   3549       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
   3550                           DAG.getConstant(NVT.getSizeInBits() -
   3551                                           OVT.getSizeInBits(), NVT));
   3552     }
   3553     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
   3554     break;
   3555   case ISD::BSWAP: {
   3556     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
   3557     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
   3558     Tmp1 = DAG.getNode(ISD::BSWAP, dl, NVT, Tmp1);
   3559     Tmp1 = DAG.getNode(ISD::SRL, dl, NVT, Tmp1,
   3560                           DAG.getConstant(DiffBits, TLI.getShiftAmountTy(NVT)));
   3561     Results.push_back(Tmp1);
   3562     break;
   3563   }
   3564   case ISD::FP_TO_UINT:
   3565   case ISD::FP_TO_SINT:
   3566     Tmp1 = PromoteLegalFP_TO_INT(Node->getOperand(0), Node->getValueType(0),
   3567                                  Node->getOpcode() == ISD::FP_TO_SINT, dl);
   3568     Results.push_back(Tmp1);
   3569     break;
   3570   case ISD::UINT_TO_FP:
   3571   case ISD::SINT_TO_FP:
   3572     Tmp1 = PromoteLegalINT_TO_FP(Node->getOperand(0), Node->getValueType(0),
   3573                                  Node->getOpcode() == ISD::SINT_TO_FP, dl);
   3574     Results.push_back(Tmp1);
   3575     break;
   3576   case ISD::VAARG: {
   3577     SDValue Chain = Node->getOperand(0); // Get the chain.
   3578     SDValue Ptr = Node->getOperand(1); // Get the pointer.
   3579 
   3580     unsigned TruncOp;
   3581     if (OVT.isVector()) {
   3582       TruncOp = ISD::BITCAST;
   3583     } else {
   3584       assert(OVT.isInteger()
   3585         && "VAARG promotion is supported only for vectors or integer types");
   3586       TruncOp = ISD::TRUNCATE;
   3587     }
   3588 
   3589     // Perform the larger operation, then convert back
   3590     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
   3591              Node->getConstantOperandVal(3));
   3592     Chain = Tmp1.getValue(1);
   3593 
   3594     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
   3595 
   3596     // Modified the chain result - switch anything that used the old chain to
   3597     // use the new one.
   3598     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
   3599     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
   3600     ReplacedNode(Node);
   3601     break;
   3602   }
   3603   case ISD::AND:
   3604   case ISD::OR:
   3605   case ISD::XOR: {
   3606     unsigned ExtOp, TruncOp;
   3607     if (OVT.isVector()) {
   3608       ExtOp   = ISD::BITCAST;
   3609       TruncOp = ISD::BITCAST;
   3610     } else {
   3611       assert(OVT.isInteger() && "Cannot promote logic operation");
   3612       ExtOp   = ISD::ANY_EXTEND;
   3613       TruncOp = ISD::TRUNCATE;
   3614     }
   3615     // Promote each of the values to the new type.
   3616     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
   3617     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
   3618     // Perform the larger operation, then convert back
   3619     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
   3620     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
   3621     break;
   3622   }
   3623   case ISD::SELECT: {
   3624     unsigned ExtOp, TruncOp;
   3625     if (Node->getValueType(0).isVector()) {
   3626       ExtOp   = ISD::BITCAST;
   3627       TruncOp = ISD::BITCAST;
   3628     } else if (Node->getValueType(0).isInteger()) {
   3629       ExtOp   = ISD::ANY_EXTEND;
   3630       TruncOp = ISD::TRUNCATE;
   3631     } else {
   3632       ExtOp   = ISD::FP_EXTEND;
   3633       TruncOp = ISD::FP_ROUND;
   3634     }
   3635     Tmp1 = Node->getOperand(0);
   3636     // Promote each of the values to the new type.
   3637     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
   3638     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
   3639     // Perform the larger operation, then round down.
   3640     Tmp1 = DAG.getNode(ISD::SELECT, dl, NVT, Tmp1, Tmp2, Tmp3);
   3641     if (TruncOp != ISD::FP_ROUND)
   3642       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
   3643     else
   3644       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
   3645                          DAG.getIntPtrConstant(0));
   3646     Results.push_back(Tmp1);
   3647     break;
   3648   }
   3649   case ISD::VECTOR_SHUFFLE: {
   3650     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
   3651 
   3652     // Cast the two input vectors.
   3653     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
   3654     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
   3655 
   3656     // Convert the shuffle mask to the right # elements.
   3657     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
   3658     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
   3659     Results.push_back(Tmp1);
   3660     break;
   3661   }
   3662   case ISD::SETCC: {
   3663     unsigned ExtOp = ISD::FP_EXTEND;
   3664     if (NVT.isInteger()) {
   3665       ISD::CondCode CCCode =
   3666         cast<CondCodeSDNode>(Node->getOperand(2))->get();
   3667       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
   3668     }
   3669     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
   3670     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
   3671     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
   3672                                   Tmp1, Tmp2, Node->getOperand(2)));
   3673     break;
   3674   }
   3675   case ISD::FDIV:
   3676   case ISD::FREM:
   3677   case ISD::FPOW: {
   3678     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
   3679     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
   3680     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
   3681     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
   3682                                   Tmp3, DAG.getIntPtrConstant(0)));
   3683     break;
   3684   }
   3685   case ISD::FLOG2:
   3686   case ISD::FEXP2:
   3687   case ISD::FLOG:
   3688   case ISD::FEXP: {
   3689     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
   3690     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
   3691     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
   3692                                   Tmp2, DAG.getIntPtrConstant(0)));
   3693     break;
   3694   }
   3695   }
   3696 
   3697   // Replace the original node with the legalized result.
   3698   if (!Results.empty())
   3699     ReplaceNode(Node, Results.data());
   3700 }
   3701 
   3702 // SelectionDAG::Legalize - This is the entry point for the file.
   3703 //
   3704 void SelectionDAG::Legalize() {
   3705   /// run - This is the main entry point to this class.
   3706   ///
   3707   SelectionDAGLegalize(*this).LegalizeDAG();
   3708 }
   3709