diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 7953 | 
1 files changed, 7953 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp new file mode 100644 index 000000000000..dff8bd2ad37d --- /dev/null +++ b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -0,0 +1,7953 @@ +//===- SelectionDAG.cpp - Implement the SelectionDAG data structures ------===// +// +//                     The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This implements the SelectionDAG class. +// +//===----------------------------------------------------------------------===// + +#include "llvm/CodeGen/SelectionDAG.h" +#include "SDNodeDbgValue.h" +#include "llvm/ADT/APFloat.h" +#include "llvm/ADT/APInt.h" +#include "llvm/ADT/APSInt.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/BitVector.h" +#include "llvm/ADT/FoldingSet.h" +#include "llvm/ADT/None.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/Triple.h" +#include "llvm/ADT/Twine.h" +#include "llvm/Analysis/ValueTracking.h" +#include "llvm/CodeGen/ISDOpcodes.h" +#include "llvm/CodeGen/MachineBasicBlock.h" +#include "llvm/CodeGen/MachineConstantPool.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineMemOperand.h" +#include "llvm/CodeGen/MachineValueType.h" +#include "llvm/CodeGen/RuntimeLibcalls.h" +#include "llvm/CodeGen/SelectionDAGNodes.h" +#include "llvm/CodeGen/SelectionDAGTargetInfo.h" +#include "llvm/CodeGen/ValueTypes.h" +#include "llvm/IR/Constant.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DebugInfoMetadata.h" +#include "llvm/IR/DebugLoc.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/GlobalValue.h" +#include "llvm/IR/Metadata.h" +#include "llvm/IR/Type.h" +#include "llvm/IR/Value.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/CodeGen.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/KnownBits.h" +#include "llvm/Support/ManagedStatic.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/Support/Mutex.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetLowering.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetSubtargetInfo.h" +#include <algorithm> +#include <cassert> +#include <cstdint> +#include <cstdlib> +#include <limits> +#include <set> +#include <string> +#include <utility> +#include <vector> + +using namespace llvm; + +/// makeVTList - Return an instance of the SDVTList struct initialized with the +/// specified members. +static SDVTList makeVTList(const EVT *VTs, unsigned NumVTs) { +  SDVTList Res = {VTs, NumVTs}; +  return Res; +} + +// Default null implementations of the callbacks. +void SelectionDAG::DAGUpdateListener::NodeDeleted(SDNode*, SDNode*) {} +void SelectionDAG::DAGUpdateListener::NodeUpdated(SDNode*) {} + +//===----------------------------------------------------------------------===// +//                              ConstantFPSDNode Class +//===----------------------------------------------------------------------===// + +/// isExactlyValue - We don't rely on operator== working on double values, as +/// it returns true for things that are clearly not equal, like -0.0 and 0.0. +/// As such, this method can be used to do an exact bit-for-bit comparison of +/// two floating point values. +bool ConstantFPSDNode::isExactlyValue(const APFloat& V) const { +  return getValueAPF().bitwiseIsEqual(V); +} + +bool ConstantFPSDNode::isValueValidForType(EVT VT, +                                           const APFloat& Val) { +  assert(VT.isFloatingPoint() && "Can only convert between FP types"); + +  // convert modifies in place, so make a copy. +  APFloat Val2 = APFloat(Val); +  bool losesInfo; +  (void) Val2.convert(SelectionDAG::EVTToAPFloatSemantics(VT), +                      APFloat::rmNearestTiesToEven, +                      &losesInfo); +  return !losesInfo; +} + +//===----------------------------------------------------------------------===// +//                              ISD Namespace +//===----------------------------------------------------------------------===// + +bool ISD::isConstantSplatVector(const SDNode *N, APInt &SplatVal) { +  auto *BV = dyn_cast<BuildVectorSDNode>(N); +  if (!BV) +    return false; + +  APInt SplatUndef; +  unsigned SplatBitSize; +  bool HasUndefs; +  EVT EltVT = N->getValueType(0).getVectorElementType(); +  return BV->isConstantSplat(SplatVal, SplatUndef, SplatBitSize, HasUndefs) && +         EltVT.getSizeInBits() >= SplatBitSize; +} + +// FIXME: AllOnes and AllZeros duplicate a lot of code. Could these be +// specializations of the more general isConstantSplatVector()? + +bool ISD::isBuildVectorAllOnes(const SDNode *N) { +  // Look through a bit convert. +  while (N->getOpcode() == ISD::BITCAST) +    N = N->getOperand(0).getNode(); + +  if (N->getOpcode() != ISD::BUILD_VECTOR) return false; + +  unsigned i = 0, e = N->getNumOperands(); + +  // Skip over all of the undef values. +  while (i != e && N->getOperand(i).isUndef()) +    ++i; + +  // Do not accept an all-undef vector. +  if (i == e) return false; + +  // Do not accept build_vectors that aren't all constants or which have non-~0 +  // elements. We have to be a bit careful here, as the type of the constant +  // may not be the same as the type of the vector elements due to type +  // legalization (the elements are promoted to a legal type for the target and +  // a vector of a type may be legal when the base element type is not). +  // We only want to check enough bits to cover the vector elements, because +  // we care if the resultant vector is all ones, not whether the individual +  // constants are. +  SDValue NotZero = N->getOperand(i); +  unsigned EltSize = N->getValueType(0).getScalarSizeInBits(); +  if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(NotZero)) { +    if (CN->getAPIntValue().countTrailingOnes() < EltSize) +      return false; +  } else if (ConstantFPSDNode *CFPN = dyn_cast<ConstantFPSDNode>(NotZero)) { +    if (CFPN->getValueAPF().bitcastToAPInt().countTrailingOnes() < EltSize) +      return false; +  } else +    return false; + +  // Okay, we have at least one ~0 value, check to see if the rest match or are +  // undefs. Even with the above element type twiddling, this should be OK, as +  // the same type legalization should have applied to all the elements. +  for (++i; i != e; ++i) +    if (N->getOperand(i) != NotZero && !N->getOperand(i).isUndef()) +      return false; +  return true; +} + +bool ISD::isBuildVectorAllZeros(const SDNode *N) { +  // Look through a bit convert. +  while (N->getOpcode() == ISD::BITCAST) +    N = N->getOperand(0).getNode(); + +  if (N->getOpcode() != ISD::BUILD_VECTOR) return false; + +  bool IsAllUndef = true; +  for (const SDValue &Op : N->op_values()) { +    if (Op.isUndef()) +      continue; +    IsAllUndef = false; +    // Do not accept build_vectors that aren't all constants or which have non-0 +    // elements. We have to be a bit careful here, as the type of the constant +    // may not be the same as the type of the vector elements due to type +    // legalization (the elements are promoted to a legal type for the target +    // and a vector of a type may be legal when the base element type is not). +    // We only want to check enough bits to cover the vector elements, because +    // we care if the resultant vector is all zeros, not whether the individual +    // constants are. +    unsigned EltSize = N->getValueType(0).getScalarSizeInBits(); +    if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op)) { +      if (CN->getAPIntValue().countTrailingZeros() < EltSize) +        return false; +    } else if (ConstantFPSDNode *CFPN = dyn_cast<ConstantFPSDNode>(Op)) { +      if (CFPN->getValueAPF().bitcastToAPInt().countTrailingZeros() < EltSize) +        return false; +    } else +      return false; +  } + +  // Do not accept an all-undef vector. +  if (IsAllUndef) +    return false; +  return true; +} + +bool ISD::isBuildVectorOfConstantSDNodes(const SDNode *N) { +  if (N->getOpcode() != ISD::BUILD_VECTOR) +    return false; + +  for (const SDValue &Op : N->op_values()) { +    if (Op.isUndef()) +      continue; +    if (!isa<ConstantSDNode>(Op)) +      return false; +  } +  return true; +} + +bool ISD::isBuildVectorOfConstantFPSDNodes(const SDNode *N) { +  if (N->getOpcode() != ISD::BUILD_VECTOR) +    return false; + +  for (const SDValue &Op : N->op_values()) { +    if (Op.isUndef()) +      continue; +    if (!isa<ConstantFPSDNode>(Op)) +      return false; +  } +  return true; +} + +bool ISD::allOperandsUndef(const SDNode *N) { +  // Return false if the node has no operands. +  // This is "logically inconsistent" with the definition of "all" but +  // is probably the desired behavior. +  if (N->getNumOperands() == 0) +    return false; + +  for (const SDValue &Op : N->op_values()) +    if (!Op.isUndef()) +      return false; + +  return true; +} + +ISD::NodeType ISD::getExtForLoadExtType(bool IsFP, ISD::LoadExtType ExtType) { +  switch (ExtType) { +  case ISD::EXTLOAD: +    return IsFP ? ISD::FP_EXTEND : ISD::ANY_EXTEND; +  case ISD::SEXTLOAD: +    return ISD::SIGN_EXTEND; +  case ISD::ZEXTLOAD: +    return ISD::ZERO_EXTEND; +  default: +    break; +  } + +  llvm_unreachable("Invalid LoadExtType"); +} + +ISD::CondCode ISD::getSetCCSwappedOperands(ISD::CondCode Operation) { +  // To perform this operation, we just need to swap the L and G bits of the +  // operation. +  unsigned OldL = (Operation >> 2) & 1; +  unsigned OldG = (Operation >> 1) & 1; +  return ISD::CondCode((Operation & ~6) |  // Keep the N, U, E bits +                       (OldL << 1) |       // New G bit +                       (OldG << 2));       // New L bit. +} + +ISD::CondCode ISD::getSetCCInverse(ISD::CondCode Op, bool isInteger) { +  unsigned Operation = Op; +  if (isInteger) +    Operation ^= 7;   // Flip L, G, E bits, but not U. +  else +    Operation ^= 15;  // Flip all of the condition bits. + +  if (Operation > ISD::SETTRUE2) +    Operation &= ~8;  // Don't let N and U bits get set. + +  return ISD::CondCode(Operation); +} + +/// For an integer comparison, return 1 if the comparison is a signed operation +/// and 2 if the result is an unsigned comparison. Return zero if the operation +/// does not depend on the sign of the input (setne and seteq). +static int isSignedOp(ISD::CondCode Opcode) { +  switch (Opcode) { +  default: llvm_unreachable("Illegal integer setcc operation!"); +  case ISD::SETEQ: +  case ISD::SETNE: return 0; +  case ISD::SETLT: +  case ISD::SETLE: +  case ISD::SETGT: +  case ISD::SETGE: return 1; +  case ISD::SETULT: +  case ISD::SETULE: +  case ISD::SETUGT: +  case ISD::SETUGE: return 2; +  } +} + +ISD::CondCode ISD::getSetCCOrOperation(ISD::CondCode Op1, ISD::CondCode Op2, +                                       bool IsInteger) { +  if (IsInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3) +    // Cannot fold a signed integer setcc with an unsigned integer setcc. +    return ISD::SETCC_INVALID; + +  unsigned Op = Op1 | Op2;  // Combine all of the condition bits. + +  // If the N and U bits get set, then the resultant comparison DOES suddenly +  // care about orderedness, and it is true when ordered. +  if (Op > ISD::SETTRUE2) +    Op &= ~16;     // Clear the U bit if the N bit is set. + +  // Canonicalize illegal integer setcc's. +  if (IsInteger && Op == ISD::SETUNE)  // e.g. SETUGT | SETULT +    Op = ISD::SETNE; + +  return ISD::CondCode(Op); +} + +ISD::CondCode ISD::getSetCCAndOperation(ISD::CondCode Op1, ISD::CondCode Op2, +                                        bool IsInteger) { +  if (IsInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3) +    // Cannot fold a signed setcc with an unsigned setcc. +    return ISD::SETCC_INVALID; + +  // Combine all of the condition bits. +  ISD::CondCode Result = ISD::CondCode(Op1 & Op2); + +  // Canonicalize illegal integer setcc's. +  if (IsInteger) { +    switch (Result) { +    default: break; +    case ISD::SETUO : Result = ISD::SETFALSE; break;  // SETUGT & SETULT +    case ISD::SETOEQ:                                 // SETEQ  & SETU[LG]E +    case ISD::SETUEQ: Result = ISD::SETEQ   ; break;  // SETUGE & SETULE +    case ISD::SETOLT: Result = ISD::SETULT  ; break;  // SETULT & SETNE +    case ISD::SETOGT: Result = ISD::SETUGT  ; break;  // SETUGT & SETNE +    } +  } + +  return Result; +} + +//===----------------------------------------------------------------------===// +//                           SDNode Profile Support +//===----------------------------------------------------------------------===// + +/// AddNodeIDOpcode - Add the node opcode to the NodeID data. +static void AddNodeIDOpcode(FoldingSetNodeID &ID, unsigned OpC)  { +  ID.AddInteger(OpC); +} + +/// AddNodeIDValueTypes - Value type lists are intern'd so we can represent them +/// solely with their pointer. +static void AddNodeIDValueTypes(FoldingSetNodeID &ID, SDVTList VTList) { +  ID.AddPointer(VTList.VTs); +} + +/// AddNodeIDOperands - Various routines for adding operands to the NodeID data. +static void AddNodeIDOperands(FoldingSetNodeID &ID, +                              ArrayRef<SDValue> Ops) { +  for (auto& Op : Ops) { +    ID.AddPointer(Op.getNode()); +    ID.AddInteger(Op.getResNo()); +  } +} + +/// AddNodeIDOperands - Various routines for adding operands to the NodeID data. +static void AddNodeIDOperands(FoldingSetNodeID &ID, +                              ArrayRef<SDUse> Ops) { +  for (auto& Op : Ops) { +    ID.AddPointer(Op.getNode()); +    ID.AddInteger(Op.getResNo()); +  } +} + +static void AddNodeIDNode(FoldingSetNodeID &ID, unsigned short OpC, +                          SDVTList VTList, ArrayRef<SDValue> OpList) { +  AddNodeIDOpcode(ID, OpC); +  AddNodeIDValueTypes(ID, VTList); +  AddNodeIDOperands(ID, OpList); +} + +/// If this is an SDNode with special info, add this info to the NodeID data. +static void AddNodeIDCustom(FoldingSetNodeID &ID, const SDNode *N) { +  switch (N->getOpcode()) { +  case ISD::TargetExternalSymbol: +  case ISD::ExternalSymbol: +  case ISD::MCSymbol: +    llvm_unreachable("Should only be used on nodes with operands"); +  default: break;  // Normal nodes don't need extra info. +  case ISD::TargetConstant: +  case ISD::Constant: { +    const ConstantSDNode *C = cast<ConstantSDNode>(N); +    ID.AddPointer(C->getConstantIntValue()); +    ID.AddBoolean(C->isOpaque()); +    break; +  } +  case ISD::TargetConstantFP: +  case ISD::ConstantFP: +    ID.AddPointer(cast<ConstantFPSDNode>(N)->getConstantFPValue()); +    break; +  case ISD::TargetGlobalAddress: +  case ISD::GlobalAddress: +  case ISD::TargetGlobalTLSAddress: +  case ISD::GlobalTLSAddress: { +    const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(N); +    ID.AddPointer(GA->getGlobal()); +    ID.AddInteger(GA->getOffset()); +    ID.AddInteger(GA->getTargetFlags()); +    break; +  } +  case ISD::BasicBlock: +    ID.AddPointer(cast<BasicBlockSDNode>(N)->getBasicBlock()); +    break; +  case ISD::Register: +    ID.AddInteger(cast<RegisterSDNode>(N)->getReg()); +    break; +  case ISD::RegisterMask: +    ID.AddPointer(cast<RegisterMaskSDNode>(N)->getRegMask()); +    break; +  case ISD::SRCVALUE: +    ID.AddPointer(cast<SrcValueSDNode>(N)->getValue()); +    break; +  case ISD::FrameIndex: +  case ISD::TargetFrameIndex: +    ID.AddInteger(cast<FrameIndexSDNode>(N)->getIndex()); +    break; +  case ISD::JumpTable: +  case ISD::TargetJumpTable: +    ID.AddInteger(cast<JumpTableSDNode>(N)->getIndex()); +    ID.AddInteger(cast<JumpTableSDNode>(N)->getTargetFlags()); +    break; +  case ISD::ConstantPool: +  case ISD::TargetConstantPool: { +    const ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(N); +    ID.AddInteger(CP->getAlignment()); +    ID.AddInteger(CP->getOffset()); +    if (CP->isMachineConstantPoolEntry()) +      CP->getMachineCPVal()->addSelectionDAGCSEId(ID); +    else +      ID.AddPointer(CP->getConstVal()); +    ID.AddInteger(CP->getTargetFlags()); +    break; +  } +  case ISD::TargetIndex: { +    const TargetIndexSDNode *TI = cast<TargetIndexSDNode>(N); +    ID.AddInteger(TI->getIndex()); +    ID.AddInteger(TI->getOffset()); +    ID.AddInteger(TI->getTargetFlags()); +    break; +  } +  case ISD::LOAD: { +    const LoadSDNode *LD = cast<LoadSDNode>(N); +    ID.AddInteger(LD->getMemoryVT().getRawBits()); +    ID.AddInteger(LD->getRawSubclassData()); +    ID.AddInteger(LD->getPointerInfo().getAddrSpace()); +    break; +  } +  case ISD::STORE: { +    const StoreSDNode *ST = cast<StoreSDNode>(N); +    ID.AddInteger(ST->getMemoryVT().getRawBits()); +    ID.AddInteger(ST->getRawSubclassData()); +    ID.AddInteger(ST->getPointerInfo().getAddrSpace()); +    break; +  } +  case ISD::ATOMIC_CMP_SWAP: +  case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: +  case ISD::ATOMIC_SWAP: +  case ISD::ATOMIC_LOAD_ADD: +  case ISD::ATOMIC_LOAD_SUB: +  case ISD::ATOMIC_LOAD_AND: +  case ISD::ATOMIC_LOAD_OR: +  case ISD::ATOMIC_LOAD_XOR: +  case ISD::ATOMIC_LOAD_NAND: +  case ISD::ATOMIC_LOAD_MIN: +  case ISD::ATOMIC_LOAD_MAX: +  case ISD::ATOMIC_LOAD_UMIN: +  case ISD::ATOMIC_LOAD_UMAX: +  case ISD::ATOMIC_LOAD: +  case ISD::ATOMIC_STORE: { +    const AtomicSDNode *AT = cast<AtomicSDNode>(N); +    ID.AddInteger(AT->getMemoryVT().getRawBits()); +    ID.AddInteger(AT->getRawSubclassData()); +    ID.AddInteger(AT->getPointerInfo().getAddrSpace()); +    break; +  } +  case ISD::PREFETCH: { +    const MemSDNode *PF = cast<MemSDNode>(N); +    ID.AddInteger(PF->getPointerInfo().getAddrSpace()); +    break; +  } +  case ISD::VECTOR_SHUFFLE: { +    const ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N); +    for (unsigned i = 0, e = N->getValueType(0).getVectorNumElements(); +         i != e; ++i) +      ID.AddInteger(SVN->getMaskElt(i)); +    break; +  } +  case ISD::TargetBlockAddress: +  case ISD::BlockAddress: { +    const BlockAddressSDNode *BA = cast<BlockAddressSDNode>(N); +    ID.AddPointer(BA->getBlockAddress()); +    ID.AddInteger(BA->getOffset()); +    ID.AddInteger(BA->getTargetFlags()); +    break; +  } +  } // end switch (N->getOpcode()) + +  // Target specific memory nodes could also have address spaces to check. +  if (N->isTargetMemoryOpcode()) +    ID.AddInteger(cast<MemSDNode>(N)->getPointerInfo().getAddrSpace()); +} + +/// AddNodeIDNode - Generic routine for adding a nodes info to the NodeID +/// data. +static void AddNodeIDNode(FoldingSetNodeID &ID, const SDNode *N) { +  AddNodeIDOpcode(ID, N->getOpcode()); +  // Add the return value info. +  AddNodeIDValueTypes(ID, N->getVTList()); +  // Add the operand info. +  AddNodeIDOperands(ID, N->ops()); + +  // Handle SDNode leafs with special info. +  AddNodeIDCustom(ID, N); +} + +//===----------------------------------------------------------------------===// +//                              SelectionDAG Class +//===----------------------------------------------------------------------===// + +/// doNotCSE - Return true if CSE should not be performed for this node. +static bool doNotCSE(SDNode *N) { +  if (N->getValueType(0) == MVT::Glue) +    return true; // Never CSE anything that produces a flag. + +  switch (N->getOpcode()) { +  default: break; +  case ISD::HANDLENODE: +  case ISD::EH_LABEL: +    return true;   // Never CSE these nodes. +  } + +  // Check that remaining values produced are not flags. +  for (unsigned i = 1, e = N->getNumValues(); i != e; ++i) +    if (N->getValueType(i) == MVT::Glue) +      return true; // Never CSE anything that produces a flag. + +  return false; +} + +/// RemoveDeadNodes - This method deletes all unreachable nodes in the +/// SelectionDAG. +void SelectionDAG::RemoveDeadNodes() { +  // Create a dummy node (which is not added to allnodes), that adds a reference +  // to the root node, preventing it from being deleted. +  HandleSDNode Dummy(getRoot()); + +  SmallVector<SDNode*, 128> DeadNodes; + +  // Add all obviously-dead nodes to the DeadNodes worklist. +  for (SDNode &Node : allnodes()) +    if (Node.use_empty()) +      DeadNodes.push_back(&Node); + +  RemoveDeadNodes(DeadNodes); + +  // If the root changed (e.g. it was a dead load, update the root). +  setRoot(Dummy.getValue()); +} + +/// RemoveDeadNodes - This method deletes the unreachable nodes in the +/// given list, and any nodes that become unreachable as a result. +void SelectionDAG::RemoveDeadNodes(SmallVectorImpl<SDNode *> &DeadNodes) { + +  // Process the worklist, deleting the nodes and adding their uses to the +  // worklist. +  while (!DeadNodes.empty()) { +    SDNode *N = DeadNodes.pop_back_val(); +    // Skip to next node if we've already managed to delete the node. This could +    // happen if replacing a node causes a node previously added to the node to +    // be deleted. +    if (N->getOpcode() == ISD::DELETED_NODE) +      continue; + +    for (DAGUpdateListener *DUL = UpdateListeners; DUL; DUL = DUL->Next) +      DUL->NodeDeleted(N, nullptr); + +    // Take the node out of the appropriate CSE map. +    RemoveNodeFromCSEMaps(N); + +    // Next, brutally remove the operand list.  This is safe to do, as there are +    // no cycles in the graph. +    for (SDNode::op_iterator I = N->op_begin(), E = N->op_end(); I != E; ) { +      SDUse &Use = *I++; +      SDNode *Operand = Use.getNode(); +      Use.set(SDValue()); + +      // Now that we removed this operand, see if there are no uses of it left. +      if (Operand->use_empty()) +        DeadNodes.push_back(Operand); +    } + +    DeallocateNode(N); +  } +} + +void SelectionDAG::RemoveDeadNode(SDNode *N){ +  SmallVector<SDNode*, 16> DeadNodes(1, N); + +  // Create a dummy node that adds a reference to the root node, preventing +  // it from being deleted.  (This matters if the root is an operand of the +  // dead node.) +  HandleSDNode Dummy(getRoot()); + +  RemoveDeadNodes(DeadNodes); +} + +void SelectionDAG::DeleteNode(SDNode *N) { +  // First take this out of the appropriate CSE map. +  RemoveNodeFromCSEMaps(N); + +  // Finally, remove uses due to operands of this node, remove from the +  // AllNodes list, and delete the node. +  DeleteNodeNotInCSEMaps(N); +} + +void SelectionDAG::DeleteNodeNotInCSEMaps(SDNode *N) { +  assert(N->getIterator() != AllNodes.begin() && +         "Cannot delete the entry node!"); +  assert(N->use_empty() && "Cannot delete a node that is not dead!"); + +  // Drop all of the operands and decrement used node's use counts. +  N->DropOperands(); + +  DeallocateNode(N); +} + +void SDDbgInfo::erase(const SDNode *Node) { +  DbgValMapType::iterator I = DbgValMap.find(Node); +  if (I == DbgValMap.end()) +    return; +  for (auto &Val: I->second) +    Val->setIsInvalidated(); +  DbgValMap.erase(I); +} + +void SelectionDAG::DeallocateNode(SDNode *N) { +  // If we have operands, deallocate them. +  removeOperands(N); + +  NodeAllocator.Deallocate(AllNodes.remove(N)); + +  // Set the opcode to DELETED_NODE to help catch bugs when node +  // memory is reallocated. +  // FIXME: There are places in SDag that have grown a dependency on the opcode +  // value in the released node. +  __asan_unpoison_memory_region(&N->NodeType, sizeof(N->NodeType)); +  N->NodeType = ISD::DELETED_NODE; + +  // If any of the SDDbgValue nodes refer to this SDNode, invalidate +  // them and forget about that node. +  DbgInfo->erase(N); +} + +#ifndef NDEBUG +/// VerifySDNode - Sanity check the given SDNode.  Aborts if it is invalid. +static void VerifySDNode(SDNode *N) { +  switch (N->getOpcode()) { +  default: +    break; +  case ISD::BUILD_PAIR: { +    EVT VT = N->getValueType(0); +    assert(N->getNumValues() == 1 && "Too many results!"); +    assert(!VT.isVector() && (VT.isInteger() || VT.isFloatingPoint()) && +           "Wrong return type!"); +    assert(N->getNumOperands() == 2 && "Wrong number of operands!"); +    assert(N->getOperand(0).getValueType() == N->getOperand(1).getValueType() && +           "Mismatched operand types!"); +    assert(N->getOperand(0).getValueType().isInteger() == VT.isInteger() && +           "Wrong operand type!"); +    assert(VT.getSizeInBits() == 2 * N->getOperand(0).getValueSizeInBits() && +           "Wrong return type size"); +    break; +  } +  case ISD::BUILD_VECTOR: { +    assert(N->getNumValues() == 1 && "Too many results!"); +    assert(N->getValueType(0).isVector() && "Wrong return type!"); +    assert(N->getNumOperands() == N->getValueType(0).getVectorNumElements() && +           "Wrong number of operands!"); +    EVT EltVT = N->getValueType(0).getVectorElementType(); +    for (SDNode::op_iterator I = N->op_begin(), E = N->op_end(); I != E; ++I) { +      assert((I->getValueType() == EltVT || +             (EltVT.isInteger() && I->getValueType().isInteger() && +              EltVT.bitsLE(I->getValueType()))) && +            "Wrong operand type!"); +      assert(I->getValueType() == N->getOperand(0).getValueType() && +             "Operands must all have the same type"); +    } +    break; +  } +  } +} +#endif // NDEBUG + +/// \brief Insert a newly allocated node into the DAG. +/// +/// Handles insertion into the all nodes list and CSE map, as well as +/// verification and other common operations when a new node is allocated. +void SelectionDAG::InsertNode(SDNode *N) { +  AllNodes.push_back(N); +#ifndef NDEBUG +  N->PersistentId = NextPersistentId++; +  VerifySDNode(N); +#endif +} + +/// RemoveNodeFromCSEMaps - Take the specified node out of the CSE map that +/// correspond to it.  This is useful when we're about to delete or repurpose +/// the node.  We don't want future request for structurally identical nodes +/// to return N anymore. +bool SelectionDAG::RemoveNodeFromCSEMaps(SDNode *N) { +  bool Erased = false; +  switch (N->getOpcode()) { +  case ISD::HANDLENODE: return false;  // noop. +  case ISD::CONDCODE: +    assert(CondCodeNodes[cast<CondCodeSDNode>(N)->get()] && +           "Cond code doesn't exist!"); +    Erased = CondCodeNodes[cast<CondCodeSDNode>(N)->get()] != nullptr; +    CondCodeNodes[cast<CondCodeSDNode>(N)->get()] = nullptr; +    break; +  case ISD::ExternalSymbol: +    Erased = ExternalSymbols.erase(cast<ExternalSymbolSDNode>(N)->getSymbol()); +    break; +  case ISD::TargetExternalSymbol: { +    ExternalSymbolSDNode *ESN = cast<ExternalSymbolSDNode>(N); +    Erased = TargetExternalSymbols.erase( +               std::pair<std::string,unsigned char>(ESN->getSymbol(), +                                                    ESN->getTargetFlags())); +    break; +  } +  case ISD::MCSymbol: { +    auto *MCSN = cast<MCSymbolSDNode>(N); +    Erased = MCSymbols.erase(MCSN->getMCSymbol()); +    break; +  } +  case ISD::VALUETYPE: { +    EVT VT = cast<VTSDNode>(N)->getVT(); +    if (VT.isExtended()) { +      Erased = ExtendedValueTypeNodes.erase(VT); +    } else { +      Erased = ValueTypeNodes[VT.getSimpleVT().SimpleTy] != nullptr; +      ValueTypeNodes[VT.getSimpleVT().SimpleTy] = nullptr; +    } +    break; +  } +  default: +    // Remove it from the CSE Map. +    assert(N->getOpcode() != ISD::DELETED_NODE && "DELETED_NODE in CSEMap!"); +    assert(N->getOpcode() != ISD::EntryToken && "EntryToken in CSEMap!"); +    Erased = CSEMap.RemoveNode(N); +    break; +  } +#ifndef NDEBUG +  // Verify that the node was actually in one of the CSE maps, unless it has a +  // flag result (which cannot be CSE'd) or is one of the special cases that are +  // not subject to CSE. +  if (!Erased && N->getValueType(N->getNumValues()-1) != MVT::Glue && +      !N->isMachineOpcode() && !doNotCSE(N)) { +    N->dump(this); +    dbgs() << "\n"; +    llvm_unreachable("Node is not in map!"); +  } +#endif +  return Erased; +} + +/// AddModifiedNodeToCSEMaps - The specified node has been removed from the CSE +/// maps and modified in place. Add it back to the CSE maps, unless an identical +/// node already exists, in which case transfer all its users to the existing +/// node. This transfer can potentially trigger recursive merging. +void +SelectionDAG::AddModifiedNodeToCSEMaps(SDNode *N) { +  // For node types that aren't CSE'd, just act as if no identical node +  // already exists. +  if (!doNotCSE(N)) { +    SDNode *Existing = CSEMap.GetOrInsertNode(N); +    if (Existing != N) { +      // If there was already an existing matching node, use ReplaceAllUsesWith +      // to replace the dead one with the existing one.  This can cause +      // recursive merging of other unrelated nodes down the line. +      ReplaceAllUsesWith(N, Existing); + +      // N is now dead. Inform the listeners and delete it. +      for (DAGUpdateListener *DUL = UpdateListeners; DUL; DUL = DUL->Next) +        DUL->NodeDeleted(N, Existing); +      DeleteNodeNotInCSEMaps(N); +      return; +    } +  } + +  // If the node doesn't already exist, we updated it.  Inform listeners. +  for (DAGUpdateListener *DUL = UpdateListeners; DUL; DUL = DUL->Next) +    DUL->NodeUpdated(N); +} + +/// FindModifiedNodeSlot - Find a slot for the specified node if its operands +/// were replaced with those specified.  If this node is never memoized, +/// return null, otherwise return a pointer to the slot it would take.  If a +/// node already exists with these operands, the slot will be non-null. +SDNode *SelectionDAG::FindModifiedNodeSlot(SDNode *N, SDValue Op, +                                           void *&InsertPos) { +  if (doNotCSE(N)) +    return nullptr; + +  SDValue Ops[] = { Op }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, N->getOpcode(), N->getVTList(), Ops); +  AddNodeIDCustom(ID, N); +  SDNode *Node = FindNodeOrInsertPos(ID, SDLoc(N), InsertPos); +  if (Node) +    Node->intersectFlagsWith(N->getFlags()); +  return Node; +} + +/// FindModifiedNodeSlot - Find a slot for the specified node if its operands +/// were replaced with those specified.  If this node is never memoized, +/// return null, otherwise return a pointer to the slot it would take.  If a +/// node already exists with these operands, the slot will be non-null. +SDNode *SelectionDAG::FindModifiedNodeSlot(SDNode *N, +                                           SDValue Op1, SDValue Op2, +                                           void *&InsertPos) { +  if (doNotCSE(N)) +    return nullptr; + +  SDValue Ops[] = { Op1, Op2 }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, N->getOpcode(), N->getVTList(), Ops); +  AddNodeIDCustom(ID, N); +  SDNode *Node = FindNodeOrInsertPos(ID, SDLoc(N), InsertPos); +  if (Node) +    Node->intersectFlagsWith(N->getFlags()); +  return Node; +} + +/// FindModifiedNodeSlot - Find a slot for the specified node if its operands +/// were replaced with those specified.  If this node is never memoized, +/// return null, otherwise return a pointer to the slot it would take.  If a +/// node already exists with these operands, the slot will be non-null. +SDNode *SelectionDAG::FindModifiedNodeSlot(SDNode *N, ArrayRef<SDValue> Ops, +                                           void *&InsertPos) { +  if (doNotCSE(N)) +    return nullptr; + +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, N->getOpcode(), N->getVTList(), Ops); +  AddNodeIDCustom(ID, N); +  SDNode *Node = FindNodeOrInsertPos(ID, SDLoc(N), InsertPos); +  if (Node) +    Node->intersectFlagsWith(N->getFlags()); +  return Node; +} + +unsigned SelectionDAG::getEVTAlignment(EVT VT) const { +  Type *Ty = VT == MVT::iPTR ? +                   PointerType::get(Type::getInt8Ty(*getContext()), 0) : +                   VT.getTypeForEVT(*getContext()); + +  return getDataLayout().getABITypeAlignment(Ty); +} + +// EntryNode could meaningfully have debug info if we can find it... +SelectionDAG::SelectionDAG(const TargetMachine &tm, CodeGenOpt::Level OL) +    : TM(tm), OptLevel(OL), +      EntryNode(ISD::EntryToken, 0, DebugLoc(), getVTList(MVT::Other)), +      Root(getEntryNode()) { +  InsertNode(&EntryNode); +  DbgInfo = new SDDbgInfo(); +} + +void SelectionDAG::init(MachineFunction &NewMF, +                        OptimizationRemarkEmitter &NewORE) { +  MF = &NewMF; +  ORE = &NewORE; +  TLI = getSubtarget().getTargetLowering(); +  TSI = getSubtarget().getSelectionDAGInfo(); +  Context = &MF->getFunction()->getContext(); +} + +SelectionDAG::~SelectionDAG() { +  assert(!UpdateListeners && "Dangling registered DAGUpdateListeners"); +  allnodes_clear(); +  OperandRecycler.clear(OperandAllocator); +  delete DbgInfo; +} + +void SelectionDAG::allnodes_clear() { +  assert(&*AllNodes.begin() == &EntryNode); +  AllNodes.remove(AllNodes.begin()); +  while (!AllNodes.empty()) +    DeallocateNode(&AllNodes.front()); +#ifndef NDEBUG +  NextPersistentId = 0; +#endif +} + +SDNode *SelectionDAG::FindNodeOrInsertPos(const FoldingSetNodeID &ID, +                                          void *&InsertPos) { +  SDNode *N = CSEMap.FindNodeOrInsertPos(ID, InsertPos); +  if (N) { +    switch (N->getOpcode()) { +    default: break; +    case ISD::Constant: +    case ISD::ConstantFP: +      llvm_unreachable("Querying for Constant and ConstantFP nodes requires " +                       "debug location.  Use another overload."); +    } +  } +  return N; +} + +SDNode *SelectionDAG::FindNodeOrInsertPos(const FoldingSetNodeID &ID, +                                          const SDLoc &DL, void *&InsertPos) { +  SDNode *N = CSEMap.FindNodeOrInsertPos(ID, InsertPos); +  if (N) { +    switch (N->getOpcode()) { +    case ISD::Constant: +    case ISD::ConstantFP: +      // Erase debug location from the node if the node is used at several +      // different places. Do not propagate one location to all uses as it +      // will cause a worse single stepping debugging experience. +      if (N->getDebugLoc() != DL.getDebugLoc()) +        N->setDebugLoc(DebugLoc()); +      break; +    default: +      // When the node's point of use is located earlier in the instruction +      // sequence than its prior point of use, update its debug info to the +      // earlier location. +      if (DL.getIROrder() && DL.getIROrder() < N->getIROrder()) +        N->setDebugLoc(DL.getDebugLoc()); +      break; +    } +  } +  return N; +} + +void SelectionDAG::clear() { +  allnodes_clear(); +  OperandRecycler.clear(OperandAllocator); +  OperandAllocator.Reset(); +  CSEMap.clear(); + +  ExtendedValueTypeNodes.clear(); +  ExternalSymbols.clear(); +  TargetExternalSymbols.clear(); +  MCSymbols.clear(); +  std::fill(CondCodeNodes.begin(), CondCodeNodes.end(), +            static_cast<CondCodeSDNode*>(nullptr)); +  std::fill(ValueTypeNodes.begin(), ValueTypeNodes.end(), +            static_cast<SDNode*>(nullptr)); + +  EntryNode.UseList = nullptr; +  InsertNode(&EntryNode); +  Root = getEntryNode(); +  DbgInfo->clear(); +} + +SDValue SelectionDAG::getFPExtendOrRound(SDValue Op, const SDLoc &DL, EVT VT) { +  return VT.bitsGT(Op.getValueType()) +             ? getNode(ISD::FP_EXTEND, DL, VT, Op) +             : getNode(ISD::FP_ROUND, DL, VT, Op, getIntPtrConstant(0, DL)); +} + +SDValue SelectionDAG::getAnyExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT) { +  return VT.bitsGT(Op.getValueType()) ? +    getNode(ISD::ANY_EXTEND, DL, VT, Op) : +    getNode(ISD::TRUNCATE, DL, VT, Op); +} + +SDValue SelectionDAG::getSExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT) { +  return VT.bitsGT(Op.getValueType()) ? +    getNode(ISD::SIGN_EXTEND, DL, VT, Op) : +    getNode(ISD::TRUNCATE, DL, VT, Op); +} + +SDValue SelectionDAG::getZExtOrTrunc(SDValue Op, const SDLoc &DL, EVT VT) { +  return VT.bitsGT(Op.getValueType()) ? +    getNode(ISD::ZERO_EXTEND, DL, VT, Op) : +    getNode(ISD::TRUNCATE, DL, VT, Op); +} + +SDValue SelectionDAG::getBoolExtOrTrunc(SDValue Op, const SDLoc &SL, EVT VT, +                                        EVT OpVT) { +  if (VT.bitsLE(Op.getValueType())) +    return getNode(ISD::TRUNCATE, SL, VT, Op); + +  TargetLowering::BooleanContent BType = TLI->getBooleanContents(OpVT); +  return getNode(TLI->getExtendForContent(BType), SL, VT, Op); +} + +SDValue SelectionDAG::getZeroExtendInReg(SDValue Op, const SDLoc &DL, EVT VT) { +  assert(!VT.isVector() && +         "getZeroExtendInReg should use the vector element type instead of " +         "the vector type!"); +  if (Op.getValueType() == VT) return Op; +  unsigned BitWidth = Op.getScalarValueSizeInBits(); +  APInt Imm = APInt::getLowBitsSet(BitWidth, +                                   VT.getSizeInBits()); +  return getNode(ISD::AND, DL, Op.getValueType(), Op, +                 getConstant(Imm, DL, Op.getValueType())); +} + +SDValue SelectionDAG::getAnyExtendVectorInReg(SDValue Op, const SDLoc &DL, +                                              EVT VT) { +  assert(VT.isVector() && "This DAG node is restricted to vector types."); +  assert(VT.getSizeInBits() == Op.getValueSizeInBits() && +         "The sizes of the input and result must match in order to perform the " +         "extend in-register."); +  assert(VT.getVectorNumElements() < Op.getValueType().getVectorNumElements() && +         "The destination vector type must have fewer lanes than the input."); +  return getNode(ISD::ANY_EXTEND_VECTOR_INREG, DL, VT, Op); +} + +SDValue SelectionDAG::getSignExtendVectorInReg(SDValue Op, const SDLoc &DL, +                                               EVT VT) { +  assert(VT.isVector() && "This DAG node is restricted to vector types."); +  assert(VT.getSizeInBits() == Op.getValueSizeInBits() && +         "The sizes of the input and result must match in order to perform the " +         "extend in-register."); +  assert(VT.getVectorNumElements() < Op.getValueType().getVectorNumElements() && +         "The destination vector type must have fewer lanes than the input."); +  return getNode(ISD::SIGN_EXTEND_VECTOR_INREG, DL, VT, Op); +} + +SDValue SelectionDAG::getZeroExtendVectorInReg(SDValue Op, const SDLoc &DL, +                                               EVT VT) { +  assert(VT.isVector() && "This DAG node is restricted to vector types."); +  assert(VT.getSizeInBits() == Op.getValueSizeInBits() && +         "The sizes of the input and result must match in order to perform the " +         "extend in-register."); +  assert(VT.getVectorNumElements() < Op.getValueType().getVectorNumElements() && +         "The destination vector type must have fewer lanes than the input."); +  return getNode(ISD::ZERO_EXTEND_VECTOR_INREG, DL, VT, Op); +} + +/// getNOT - Create a bitwise NOT operation as (XOR Val, -1). +SDValue SelectionDAG::getNOT(const SDLoc &DL, SDValue Val, EVT VT) { +  EVT EltVT = VT.getScalarType(); +  SDValue NegOne = +    getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), DL, VT); +  return getNode(ISD::XOR, DL, VT, Val, NegOne); +} + +SDValue SelectionDAG::getLogicalNOT(const SDLoc &DL, SDValue Val, EVT VT) { +  EVT EltVT = VT.getScalarType(); +  SDValue TrueValue; +  switch (TLI->getBooleanContents(VT)) { +    case TargetLowering::ZeroOrOneBooleanContent: +    case TargetLowering::UndefinedBooleanContent: +      TrueValue = getConstant(1, DL, VT); +      break; +    case TargetLowering::ZeroOrNegativeOneBooleanContent: +      TrueValue = getConstant(APInt::getAllOnesValue(EltVT.getSizeInBits()), DL, +                              VT); +      break; +  } +  return getNode(ISD::XOR, DL, VT, Val, TrueValue); +} + +SDValue SelectionDAG::getConstant(uint64_t Val, const SDLoc &DL, EVT VT, +                                  bool isT, bool isO) { +  EVT EltVT = VT.getScalarType(); +  assert((EltVT.getSizeInBits() >= 64 || +         (uint64_t)((int64_t)Val >> EltVT.getSizeInBits()) + 1 < 2) && +         "getConstant with a uint64_t value that doesn't fit in the type!"); +  return getConstant(APInt(EltVT.getSizeInBits(), Val), DL, VT, isT, isO); +} + +SDValue SelectionDAG::getConstant(const APInt &Val, const SDLoc &DL, EVT VT, +                                  bool isT, bool isO) { +  return getConstant(*ConstantInt::get(*Context, Val), DL, VT, isT, isO); +} + +SDValue SelectionDAG::getConstant(const ConstantInt &Val, const SDLoc &DL, +                                  EVT VT, bool isT, bool isO) { +  assert(VT.isInteger() && "Cannot create FP integer constant!"); + +  EVT EltVT = VT.getScalarType(); +  const ConstantInt *Elt = &Val; + +  // In some cases the vector type is legal but the element type is illegal and +  // needs to be promoted, for example v8i8 on ARM.  In this case, promote the +  // inserted value (the type does not need to match the vector element type). +  // Any extra bits introduced will be truncated away. +  if (VT.isVector() && TLI->getTypeAction(*getContext(), EltVT) == +      TargetLowering::TypePromoteInteger) { +   EltVT = TLI->getTypeToTransformTo(*getContext(), EltVT); +   APInt NewVal = Elt->getValue().zextOrTrunc(EltVT.getSizeInBits()); +   Elt = ConstantInt::get(*getContext(), NewVal); +  } +  // In other cases the element type is illegal and needs to be expanded, for +  // example v2i64 on MIPS32. In this case, find the nearest legal type, split +  // the value into n parts and use a vector type with n-times the elements. +  // Then bitcast to the type requested. +  // Legalizing constants too early makes the DAGCombiner's job harder so we +  // only legalize if the DAG tells us we must produce legal types. +  else if (NewNodesMustHaveLegalTypes && VT.isVector() && +           TLI->getTypeAction(*getContext(), EltVT) == +           TargetLowering::TypeExpandInteger) { +    const APInt &NewVal = Elt->getValue(); +    EVT ViaEltVT = TLI->getTypeToTransformTo(*getContext(), EltVT); +    unsigned ViaEltSizeInBits = ViaEltVT.getSizeInBits(); +    unsigned ViaVecNumElts = VT.getSizeInBits() / ViaEltSizeInBits; +    EVT ViaVecVT = EVT::getVectorVT(*getContext(), ViaEltVT, ViaVecNumElts); + +    // Check the temporary vector is the correct size. If this fails then +    // getTypeToTransformTo() probably returned a type whose size (in bits) +    // isn't a power-of-2 factor of the requested type size. +    assert(ViaVecVT.getSizeInBits() == VT.getSizeInBits()); + +    SmallVector<SDValue, 2> EltParts; +    for (unsigned i = 0; i < ViaVecNumElts / VT.getVectorNumElements(); ++i) { +      EltParts.push_back(getConstant(NewVal.lshr(i * ViaEltSizeInBits) +                                           .zextOrTrunc(ViaEltSizeInBits), DL, +                                     ViaEltVT, isT, isO)); +    } + +    // EltParts is currently in little endian order. If we actually want +    // big-endian order then reverse it now. +    if (getDataLayout().isBigEndian()) +      std::reverse(EltParts.begin(), EltParts.end()); + +    // The elements must be reversed when the element order is different +    // to the endianness of the elements (because the BITCAST is itself a +    // vector shuffle in this situation). However, we do not need any code to +    // perform this reversal because getConstant() is producing a vector +    // splat. +    // This situation occurs in MIPS MSA. + +    SmallVector<SDValue, 8> Ops; +    for (unsigned i = 0, e = VT.getVectorNumElements(); i != e; ++i) +      Ops.insert(Ops.end(), EltParts.begin(), EltParts.end()); +    return getNode(ISD::BITCAST, DL, VT, getBuildVector(ViaVecVT, DL, Ops)); +  } + +  assert(Elt->getBitWidth() == EltVT.getSizeInBits() && +         "APInt size does not match type size!"); +  unsigned Opc = isT ? ISD::TargetConstant : ISD::Constant; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(EltVT), None); +  ID.AddPointer(Elt); +  ID.AddBoolean(isO); +  void *IP = nullptr; +  SDNode *N = nullptr; +  if ((N = FindNodeOrInsertPos(ID, DL, IP))) +    if (!VT.isVector()) +      return SDValue(N, 0); + +  if (!N) { +    N = newSDNode<ConstantSDNode>(isT, isO, Elt, DL.getDebugLoc(), EltVT); +    CSEMap.InsertNode(N, IP); +    InsertNode(N); +  } + +  SDValue Result(N, 0); +  if (VT.isVector()) +    Result = getSplatBuildVector(VT, DL, Result); +  return Result; +} + +SDValue SelectionDAG::getIntPtrConstant(uint64_t Val, const SDLoc &DL, +                                        bool isTarget) { +  return getConstant(Val, DL, TLI->getPointerTy(getDataLayout()), isTarget); +} + +SDValue SelectionDAG::getConstantFP(const APFloat &V, const SDLoc &DL, EVT VT, +                                    bool isTarget) { +  return getConstantFP(*ConstantFP::get(*getContext(), V), DL, VT, isTarget); +} + +SDValue SelectionDAG::getConstantFP(const ConstantFP &V, const SDLoc &DL, +                                    EVT VT, bool isTarget) { +  assert(VT.isFloatingPoint() && "Cannot create integer FP constant!"); + +  EVT EltVT = VT.getScalarType(); + +  // Do the map lookup using the actual bit pattern for the floating point +  // value, so that we don't have problems with 0.0 comparing equal to -0.0, and +  // we don't have issues with SNANs. +  unsigned Opc = isTarget ? ISD::TargetConstantFP : ISD::ConstantFP; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(EltVT), None); +  ID.AddPointer(&V); +  void *IP = nullptr; +  SDNode *N = nullptr; +  if ((N = FindNodeOrInsertPos(ID, DL, IP))) +    if (!VT.isVector()) +      return SDValue(N, 0); + +  if (!N) { +    N = newSDNode<ConstantFPSDNode>(isTarget, &V, DL.getDebugLoc(), EltVT); +    CSEMap.InsertNode(N, IP); +    InsertNode(N); +  } + +  SDValue Result(N, 0); +  if (VT.isVector()) +    Result = getSplatBuildVector(VT, DL, Result); +  return Result; +} + +SDValue SelectionDAG::getConstantFP(double Val, const SDLoc &DL, EVT VT, +                                    bool isTarget) { +  EVT EltVT = VT.getScalarType(); +  if (EltVT == MVT::f32) +    return getConstantFP(APFloat((float)Val), DL, VT, isTarget); +  else if (EltVT == MVT::f64) +    return getConstantFP(APFloat(Val), DL, VT, isTarget); +  else if (EltVT == MVT::f80 || EltVT == MVT::f128 || EltVT == MVT::ppcf128 || +           EltVT == MVT::f16) { +    bool Ignored; +    APFloat APF = APFloat(Val); +    APF.convert(EVTToAPFloatSemantics(EltVT), APFloat::rmNearestTiesToEven, +                &Ignored); +    return getConstantFP(APF, DL, VT, isTarget); +  } else +    llvm_unreachable("Unsupported type in getConstantFP"); +} + +SDValue SelectionDAG::getGlobalAddress(const GlobalValue *GV, const SDLoc &DL, +                                       EVT VT, int64_t Offset, bool isTargetGA, +                                       unsigned char TargetFlags) { +  assert((TargetFlags == 0 || isTargetGA) && +         "Cannot set target flags on target-independent globals"); + +  // Truncate (with sign-extension) the offset value to the pointer size. +  unsigned BitWidth = getDataLayout().getPointerTypeSizeInBits(GV->getType()); +  if (BitWidth < 64) +    Offset = SignExtend64(Offset, BitWidth); + +  unsigned Opc; +  if (GV->isThreadLocal()) +    Opc = isTargetGA ? ISD::TargetGlobalTLSAddress : ISD::GlobalTLSAddress; +  else +    Opc = isTargetGA ? ISD::TargetGlobalAddress : ISD::GlobalAddress; + +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(VT), None); +  ID.AddPointer(GV); +  ID.AddInteger(Offset); +  ID.AddInteger(TargetFlags); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<GlobalAddressSDNode>( +      Opc, DL.getIROrder(), DL.getDebugLoc(), GV, VT, Offset, TargetFlags); +  CSEMap.InsertNode(N, IP); +    InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getFrameIndex(int FI, EVT VT, bool isTarget) { +  unsigned Opc = isTarget ? ISD::TargetFrameIndex : ISD::FrameIndex; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(VT), None); +  ID.AddInteger(FI); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<FrameIndexSDNode>(FI, VT, isTarget); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getJumpTable(int JTI, EVT VT, bool isTarget, +                                   unsigned char TargetFlags) { +  assert((TargetFlags == 0 || isTarget) && +         "Cannot set target flags on target-independent jump tables"); +  unsigned Opc = isTarget ? ISD::TargetJumpTable : ISD::JumpTable; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(VT), None); +  ID.AddInteger(JTI); +  ID.AddInteger(TargetFlags); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<JumpTableSDNode>(JTI, VT, isTarget, TargetFlags); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getConstantPool(const Constant *C, EVT VT, +                                      unsigned Alignment, int Offset, +                                      bool isTarget, +                                      unsigned char TargetFlags) { +  assert((TargetFlags == 0 || isTarget) && +         "Cannot set target flags on target-independent globals"); +  if (Alignment == 0) +    Alignment = MF->getFunction()->optForSize() +                    ? getDataLayout().getABITypeAlignment(C->getType()) +                    : getDataLayout().getPrefTypeAlignment(C->getType()); +  unsigned Opc = isTarget ? ISD::TargetConstantPool : ISD::ConstantPool; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(VT), None); +  ID.AddInteger(Alignment); +  ID.AddInteger(Offset); +  ID.AddPointer(C); +  ID.AddInteger(TargetFlags); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<ConstantPoolSDNode>(isTarget, C, VT, Offset, Alignment, +                                          TargetFlags); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getConstantPool(MachineConstantPoolValue *C, EVT VT, +                                      unsigned Alignment, int Offset, +                                      bool isTarget, +                                      unsigned char TargetFlags) { +  assert((TargetFlags == 0 || isTarget) && +         "Cannot set target flags on target-independent globals"); +  if (Alignment == 0) +    Alignment = getDataLayout().getPrefTypeAlignment(C->getType()); +  unsigned Opc = isTarget ? ISD::TargetConstantPool : ISD::ConstantPool; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(VT), None); +  ID.AddInteger(Alignment); +  ID.AddInteger(Offset); +  C->addSelectionDAGCSEId(ID); +  ID.AddInteger(TargetFlags); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<ConstantPoolSDNode>(isTarget, C, VT, Offset, Alignment, +                                          TargetFlags); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getTargetIndex(int Index, EVT VT, int64_t Offset, +                                     unsigned char TargetFlags) { +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::TargetIndex, getVTList(VT), None); +  ID.AddInteger(Index); +  ID.AddInteger(Offset); +  ID.AddInteger(TargetFlags); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<TargetIndexSDNode>(Index, VT, Offset, TargetFlags); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getBasicBlock(MachineBasicBlock *MBB) { +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::BasicBlock, getVTList(MVT::Other), None); +  ID.AddPointer(MBB); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<BasicBlockSDNode>(MBB); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getValueType(EVT VT) { +  if (VT.isSimple() && (unsigned)VT.getSimpleVT().SimpleTy >= +      ValueTypeNodes.size()) +    ValueTypeNodes.resize(VT.getSimpleVT().SimpleTy+1); + +  SDNode *&N = VT.isExtended() ? +    ExtendedValueTypeNodes[VT] : ValueTypeNodes[VT.getSimpleVT().SimpleTy]; + +  if (N) return SDValue(N, 0); +  N = newSDNode<VTSDNode>(VT); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getExternalSymbol(const char *Sym, EVT VT) { +  SDNode *&N = ExternalSymbols[Sym]; +  if (N) return SDValue(N, 0); +  N = newSDNode<ExternalSymbolSDNode>(false, Sym, 0, VT); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getMCSymbol(MCSymbol *Sym, EVT VT) { +  SDNode *&N = MCSymbols[Sym]; +  if (N) +    return SDValue(N, 0); +  N = newSDNode<MCSymbolSDNode>(Sym, VT); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getTargetExternalSymbol(const char *Sym, EVT VT, +                                              unsigned char TargetFlags) { +  SDNode *&N = +    TargetExternalSymbols[std::pair<std::string,unsigned char>(Sym, +                                                               TargetFlags)]; +  if (N) return SDValue(N, 0); +  N = newSDNode<ExternalSymbolSDNode>(true, Sym, TargetFlags, VT); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getCondCode(ISD::CondCode Cond) { +  if ((unsigned)Cond >= CondCodeNodes.size()) +    CondCodeNodes.resize(Cond+1); + +  if (!CondCodeNodes[Cond]) { +    auto *N = newSDNode<CondCodeSDNode>(Cond); +    CondCodeNodes[Cond] = N; +    InsertNode(N); +  } + +  return SDValue(CondCodeNodes[Cond], 0); +} + +/// Swaps the values of N1 and N2. Swaps all indices in the shuffle mask M that +/// point at N1 to point at N2 and indices that point at N2 to point at N1. +static void commuteShuffle(SDValue &N1, SDValue &N2, MutableArrayRef<int> M) { +  std::swap(N1, N2); +  ShuffleVectorSDNode::commuteMask(M); +} + +SDValue SelectionDAG::getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1, +                                       SDValue N2, ArrayRef<int> Mask) { +  assert(VT.getVectorNumElements() == Mask.size() && +           "Must have the same number of vector elements as mask elements!"); +  assert(VT == N1.getValueType() && VT == N2.getValueType() && +         "Invalid VECTOR_SHUFFLE"); + +  // Canonicalize shuffle undef, undef -> undef +  if (N1.isUndef() && N2.isUndef()) +    return getUNDEF(VT); + +  // Validate that all indices in Mask are within the range of the elements +  // input to the shuffle. +  int NElts = Mask.size(); +  assert(llvm::all_of(Mask, [&](int M) { return M < (NElts * 2); }) && +         "Index out of range"); + +  // Copy the mask so we can do any needed cleanup. +  SmallVector<int, 8> MaskVec(Mask.begin(), Mask.end()); + +  // Canonicalize shuffle v, v -> v, undef +  if (N1 == N2) { +    N2 = getUNDEF(VT); +    for (int i = 0; i != NElts; ++i) +      if (MaskVec[i] >= NElts) MaskVec[i] -= NElts; +  } + +  // Canonicalize shuffle undef, v -> v, undef.  Commute the shuffle mask. +  if (N1.isUndef()) +    commuteShuffle(N1, N2, MaskVec); + +  // If shuffling a splat, try to blend the splat instead. We do this here so +  // that even when this arises during lowering we don't have to re-handle it. +  auto BlendSplat = [&](BuildVectorSDNode *BV, int Offset) { +    BitVector UndefElements; +    SDValue Splat = BV->getSplatValue(&UndefElements); +    if (!Splat) +      return; + +    for (int i = 0; i < NElts; ++i) { +      if (MaskVec[i] < Offset || MaskVec[i] >= (Offset + NElts)) +        continue; + +      // If this input comes from undef, mark it as such. +      if (UndefElements[MaskVec[i] - Offset]) { +        MaskVec[i] = -1; +        continue; +      } + +      // If we can blend a non-undef lane, use that instead. +      if (!UndefElements[i]) +        MaskVec[i] = i + Offset; +    } +  }; +  if (auto *N1BV = dyn_cast<BuildVectorSDNode>(N1)) +    BlendSplat(N1BV, 0); +  if (auto *N2BV = dyn_cast<BuildVectorSDNode>(N2)) +    BlendSplat(N2BV, NElts); + +  // Canonicalize all index into lhs, -> shuffle lhs, undef +  // Canonicalize all index into rhs, -> shuffle rhs, undef +  bool AllLHS = true, AllRHS = true; +  bool N2Undef = N2.isUndef(); +  for (int i = 0; i != NElts; ++i) { +    if (MaskVec[i] >= NElts) { +      if (N2Undef) +        MaskVec[i] = -1; +      else +        AllLHS = false; +    } else if (MaskVec[i] >= 0) { +      AllRHS = false; +    } +  } +  if (AllLHS && AllRHS) +    return getUNDEF(VT); +  if (AllLHS && !N2Undef) +    N2 = getUNDEF(VT); +  if (AllRHS) { +    N1 = getUNDEF(VT); +    commuteShuffle(N1, N2, MaskVec); +  } +  // Reset our undef status after accounting for the mask. +  N2Undef = N2.isUndef(); +  // Re-check whether both sides ended up undef. +  if (N1.isUndef() && N2Undef) +    return getUNDEF(VT); + +  // If Identity shuffle return that node. +  bool Identity = true, AllSame = true; +  for (int i = 0; i != NElts; ++i) { +    if (MaskVec[i] >= 0 && MaskVec[i] != i) Identity = false; +    if (MaskVec[i] != MaskVec[0]) AllSame = false; +  } +  if (Identity && NElts) +    return N1; + +  // Shuffling a constant splat doesn't change the result. +  if (N2Undef) { +    SDValue V = N1; + +    // Look through any bitcasts. We check that these don't change the number +    // (and size) of elements and just changes their types. +    while (V.getOpcode() == ISD::BITCAST) +      V = V->getOperand(0); + +    // A splat should always show up as a build vector node. +    if (auto *BV = dyn_cast<BuildVectorSDNode>(V)) { +      BitVector UndefElements; +      SDValue Splat = BV->getSplatValue(&UndefElements); +      // If this is a splat of an undef, shuffling it is also undef. +      if (Splat && Splat.isUndef()) +        return getUNDEF(VT); + +      bool SameNumElts = +          V.getValueType().getVectorNumElements() == VT.getVectorNumElements(); + +      // We only have a splat which can skip shuffles if there is a splatted +      // value and no undef lanes rearranged by the shuffle. +      if (Splat && UndefElements.none()) { +        // Splat of <x, x, ..., x>, return <x, x, ..., x>, provided that the +        // number of elements match or the value splatted is a zero constant. +        if (SameNumElts) +          return N1; +        if (auto *C = dyn_cast<ConstantSDNode>(Splat)) +          if (C->isNullValue()) +            return N1; +      } + +      // If the shuffle itself creates a splat, build the vector directly. +      if (AllSame && SameNumElts) { +        EVT BuildVT = BV->getValueType(0); +        const SDValue &Splatted = BV->getOperand(MaskVec[0]); +        SDValue NewBV = getSplatBuildVector(BuildVT, dl, Splatted); + +        // We may have jumped through bitcasts, so the type of the +        // BUILD_VECTOR may not match the type of the shuffle. +        if (BuildVT != VT) +          NewBV = getNode(ISD::BITCAST, dl, VT, NewBV); +        return NewBV; +      } +    } +  } + +  FoldingSetNodeID ID; +  SDValue Ops[2] = { N1, N2 }; +  AddNodeIDNode(ID, ISD::VECTOR_SHUFFLE, getVTList(VT), Ops); +  for (int i = 0; i != NElts; ++i) +    ID.AddInteger(MaskVec[i]); + +  void* IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) +    return SDValue(E, 0); + +  // Allocate the mask array for the node out of the BumpPtrAllocator, since +  // SDNode doesn't have access to it.  This memory will be "leaked" when +  // the node is deallocated, but recovered when the NodeAllocator is released. +  int *MaskAlloc = OperandAllocator.Allocate<int>(NElts); +  std::copy(MaskVec.begin(), MaskVec.end(), MaskAlloc); + +  auto *N = newSDNode<ShuffleVectorSDNode>(VT, dl.getIROrder(), +                                           dl.getDebugLoc(), MaskAlloc); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getCommutedVectorShuffle(const ShuffleVectorSDNode &SV) { +  MVT VT = SV.getSimpleValueType(0); +  SmallVector<int, 8> MaskVec(SV.getMask().begin(), SV.getMask().end()); +  ShuffleVectorSDNode::commuteMask(MaskVec); + +  SDValue Op0 = SV.getOperand(0); +  SDValue Op1 = SV.getOperand(1); +  return getVectorShuffle(VT, SDLoc(&SV), Op1, Op0, MaskVec); +} + +SDValue SelectionDAG::getRegister(unsigned RegNo, EVT VT) { +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::Register, getVTList(VT), None); +  ID.AddInteger(RegNo); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<RegisterSDNode>(RegNo, VT); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getRegisterMask(const uint32_t *RegMask) { +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::RegisterMask, getVTList(MVT::Untyped), None); +  ID.AddPointer(RegMask); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<RegisterMaskSDNode>(RegMask); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getEHLabel(const SDLoc &dl, SDValue Root, +                                 MCSymbol *Label) { +  FoldingSetNodeID ID; +  SDValue Ops[] = { Root }; +  AddNodeIDNode(ID, ISD::EH_LABEL, getVTList(MVT::Other), Ops); +  ID.AddPointer(Label); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<EHLabelSDNode>(dl.getIROrder(), dl.getDebugLoc(), Label); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getBlockAddress(const BlockAddress *BA, EVT VT, +                                      int64_t Offset, +                                      bool isTarget, +                                      unsigned char TargetFlags) { +  unsigned Opc = isTarget ? ISD::TargetBlockAddress : ISD::BlockAddress; + +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opc, getVTList(VT), None); +  ID.AddPointer(BA); +  ID.AddInteger(Offset); +  ID.AddInteger(TargetFlags); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<BlockAddressSDNode>(Opc, VT, BA, Offset, TargetFlags); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getSrcValue(const Value *V) { +  assert((!V || V->getType()->isPointerTy()) && +         "SrcValue is not a pointer?"); + +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::SRCVALUE, getVTList(MVT::Other), None); +  ID.AddPointer(V); + +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<SrcValueSDNode>(V); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getMDNode(const MDNode *MD) { +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::MDNODE_SDNODE, getVTList(MVT::Other), None); +  ID.AddPointer(MD); + +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<MDNodeSDNode>(MD); +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getBitcast(EVT VT, SDValue V) { +  if (VT == V.getValueType()) +    return V; + +  return getNode(ISD::BITCAST, SDLoc(V), VT, V); +} + +SDValue SelectionDAG::getAddrSpaceCast(const SDLoc &dl, EVT VT, SDValue Ptr, +                                       unsigned SrcAS, unsigned DestAS) { +  SDValue Ops[] = {Ptr}; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::ADDRSPACECAST, getVTList(VT), Ops); +  ID.AddInteger(SrcAS); +  ID.AddInteger(DestAS); + +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<AddrSpaceCastSDNode>(dl.getIROrder(), dl.getDebugLoc(), +                                           VT, SrcAS, DestAS); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +/// getShiftAmountOperand - Return the specified value casted to +/// the target's desired shift amount type. +SDValue SelectionDAG::getShiftAmountOperand(EVT LHSTy, SDValue Op) { +  EVT OpTy = Op.getValueType(); +  EVT ShTy = TLI->getShiftAmountTy(LHSTy, getDataLayout()); +  if (OpTy == ShTy || OpTy.isVector()) return Op; + +  return getZExtOrTrunc(Op, SDLoc(Op), ShTy); +} + +SDValue SelectionDAG::expandVAArg(SDNode *Node) { +  SDLoc dl(Node); +  const TargetLowering &TLI = getTargetLoweringInfo(); +  const Value *V = cast<SrcValueSDNode>(Node->getOperand(2))->getValue(); +  EVT VT = Node->getValueType(0); +  SDValue Tmp1 = Node->getOperand(0); +  SDValue Tmp2 = Node->getOperand(1); +  unsigned Align = Node->getConstantOperandVal(3); + +  SDValue VAListLoad = getLoad(TLI.getPointerTy(getDataLayout()), dl, Tmp1, +                               Tmp2, MachinePointerInfo(V)); +  SDValue VAList = VAListLoad; + +  if (Align > TLI.getMinStackArgumentAlignment()) { +    assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2"); + +    VAList = getNode(ISD::ADD, dl, VAList.getValueType(), VAList, +                     getConstant(Align - 1, dl, VAList.getValueType())); + +    VAList = getNode(ISD::AND, dl, VAList.getValueType(), VAList, +                     getConstant(-(int64_t)Align, dl, VAList.getValueType())); +  } + +  // Increment the pointer, VAList, to the next vaarg +  Tmp1 = getNode(ISD::ADD, dl, VAList.getValueType(), VAList, +                 getConstant(getDataLayout().getTypeAllocSize( +                                               VT.getTypeForEVT(*getContext())), +                             dl, VAList.getValueType())); +  // Store the incremented VAList to the legalized pointer +  Tmp1 = +      getStore(VAListLoad.getValue(1), dl, Tmp1, Tmp2, MachinePointerInfo(V)); +  // Load the actual argument out of the pointer VAList +  return getLoad(VT, dl, Tmp1, VAList, MachinePointerInfo()); +} + +SDValue SelectionDAG::expandVACopy(SDNode *Node) { +  SDLoc dl(Node); +  const TargetLowering &TLI = getTargetLoweringInfo(); +  // This defaults to loading a pointer from the input and storing it to the +  // output, returning the chain. +  const Value *VD = cast<SrcValueSDNode>(Node->getOperand(3))->getValue(); +  const Value *VS = cast<SrcValueSDNode>(Node->getOperand(4))->getValue(); +  SDValue Tmp1 = +      getLoad(TLI.getPointerTy(getDataLayout()), dl, Node->getOperand(0), +              Node->getOperand(2), MachinePointerInfo(VS)); +  return getStore(Tmp1.getValue(1), dl, Tmp1, Node->getOperand(1), +                  MachinePointerInfo(VD)); +} + +SDValue SelectionDAG::CreateStackTemporary(EVT VT, unsigned minAlign) { +  MachineFrameInfo &MFI = getMachineFunction().getFrameInfo(); +  unsigned ByteSize = VT.getStoreSize(); +  Type *Ty = VT.getTypeForEVT(*getContext()); +  unsigned StackAlign = +      std::max((unsigned)getDataLayout().getPrefTypeAlignment(Ty), minAlign); + +  int FrameIdx = MFI.CreateStackObject(ByteSize, StackAlign, false); +  return getFrameIndex(FrameIdx, TLI->getFrameIndexTy(getDataLayout())); +} + +SDValue SelectionDAG::CreateStackTemporary(EVT VT1, EVT VT2) { +  unsigned Bytes = std::max(VT1.getStoreSize(), VT2.getStoreSize()); +  Type *Ty1 = VT1.getTypeForEVT(*getContext()); +  Type *Ty2 = VT2.getTypeForEVT(*getContext()); +  const DataLayout &DL = getDataLayout(); +  unsigned Align = +      std::max(DL.getPrefTypeAlignment(Ty1), DL.getPrefTypeAlignment(Ty2)); + +  MachineFrameInfo &MFI = getMachineFunction().getFrameInfo(); +  int FrameIdx = MFI.CreateStackObject(Bytes, Align, false); +  return getFrameIndex(FrameIdx, TLI->getFrameIndexTy(getDataLayout())); +} + +SDValue SelectionDAG::FoldSetCC(EVT VT, SDValue N1, SDValue N2, +                                ISD::CondCode Cond, const SDLoc &dl) { +  // These setcc operations always fold. +  switch (Cond) { +  default: break; +  case ISD::SETFALSE: +  case ISD::SETFALSE2: return getConstant(0, dl, VT); +  case ISD::SETTRUE: +  case ISD::SETTRUE2: { +    TargetLowering::BooleanContent Cnt = +        TLI->getBooleanContents(N1->getValueType(0)); +    return getConstant( +        Cnt == TargetLowering::ZeroOrNegativeOneBooleanContent ? -1ULL : 1, dl, +        VT); +  } + +  case ISD::SETOEQ: +  case ISD::SETOGT: +  case ISD::SETOGE: +  case ISD::SETOLT: +  case ISD::SETOLE: +  case ISD::SETONE: +  case ISD::SETO: +  case ISD::SETUO: +  case ISD::SETUEQ: +  case ISD::SETUNE: +    assert(!N1.getValueType().isInteger() && "Illegal setcc for integer!"); +    break; +  } + +  if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2)) { +    const APInt &C2 = N2C->getAPIntValue(); +    if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1)) { +      const APInt &C1 = N1C->getAPIntValue(); + +      switch (Cond) { +      default: llvm_unreachable("Unknown integer setcc!"); +      case ISD::SETEQ:  return getConstant(C1 == C2, dl, VT); +      case ISD::SETNE:  return getConstant(C1 != C2, dl, VT); +      case ISD::SETULT: return getConstant(C1.ult(C2), dl, VT); +      case ISD::SETUGT: return getConstant(C1.ugt(C2), dl, VT); +      case ISD::SETULE: return getConstant(C1.ule(C2), dl, VT); +      case ISD::SETUGE: return getConstant(C1.uge(C2), dl, VT); +      case ISD::SETLT:  return getConstant(C1.slt(C2), dl, VT); +      case ISD::SETGT:  return getConstant(C1.sgt(C2), dl, VT); +      case ISD::SETLE:  return getConstant(C1.sle(C2), dl, VT); +      case ISD::SETGE:  return getConstant(C1.sge(C2), dl, VT); +      } +    } +  } +  if (ConstantFPSDNode *N1C = dyn_cast<ConstantFPSDNode>(N1)) { +    if (ConstantFPSDNode *N2C = dyn_cast<ConstantFPSDNode>(N2)) { +      APFloat::cmpResult R = N1C->getValueAPF().compare(N2C->getValueAPF()); +      switch (Cond) { +      default: break; +      case ISD::SETEQ:  if (R==APFloat::cmpUnordered) +                          return getUNDEF(VT); +                        LLVM_FALLTHROUGH; +      case ISD::SETOEQ: return getConstant(R==APFloat::cmpEqual, dl, VT); +      case ISD::SETNE:  if (R==APFloat::cmpUnordered) +                          return getUNDEF(VT); +                        LLVM_FALLTHROUGH; +      case ISD::SETONE: return getConstant(R==APFloat::cmpGreaterThan || +                                           R==APFloat::cmpLessThan, dl, VT); +      case ISD::SETLT:  if (R==APFloat::cmpUnordered) +                          return getUNDEF(VT); +                        LLVM_FALLTHROUGH; +      case ISD::SETOLT: return getConstant(R==APFloat::cmpLessThan, dl, VT); +      case ISD::SETGT:  if (R==APFloat::cmpUnordered) +                          return getUNDEF(VT); +                        LLVM_FALLTHROUGH; +      case ISD::SETOGT: return getConstant(R==APFloat::cmpGreaterThan, dl, VT); +      case ISD::SETLE:  if (R==APFloat::cmpUnordered) +                          return getUNDEF(VT); +                        LLVM_FALLTHROUGH; +      case ISD::SETOLE: return getConstant(R==APFloat::cmpLessThan || +                                           R==APFloat::cmpEqual, dl, VT); +      case ISD::SETGE:  if (R==APFloat::cmpUnordered) +                          return getUNDEF(VT); +                        LLVM_FALLTHROUGH; +      case ISD::SETOGE: return getConstant(R==APFloat::cmpGreaterThan || +                                           R==APFloat::cmpEqual, dl, VT); +      case ISD::SETO:   return getConstant(R!=APFloat::cmpUnordered, dl, VT); +      case ISD::SETUO:  return getConstant(R==APFloat::cmpUnordered, dl, VT); +      case ISD::SETUEQ: return getConstant(R==APFloat::cmpUnordered || +                                           R==APFloat::cmpEqual, dl, VT); +      case ISD::SETUNE: return getConstant(R!=APFloat::cmpEqual, dl, VT); +      case ISD::SETULT: return getConstant(R==APFloat::cmpUnordered || +                                           R==APFloat::cmpLessThan, dl, VT); +      case ISD::SETUGT: return getConstant(R==APFloat::cmpGreaterThan || +                                           R==APFloat::cmpUnordered, dl, VT); +      case ISD::SETULE: return getConstant(R!=APFloat::cmpGreaterThan, dl, VT); +      case ISD::SETUGE: return getConstant(R!=APFloat::cmpLessThan, dl, VT); +      } +    } else { +      // Ensure that the constant occurs on the RHS. +      ISD::CondCode SwappedCond = ISD::getSetCCSwappedOperands(Cond); +      MVT CompVT = N1.getValueType().getSimpleVT(); +      if (!TLI->isCondCodeLegal(SwappedCond, CompVT)) +        return SDValue(); + +      return getSetCC(dl, VT, N2, N1, SwappedCond); +    } +  } + +  // Could not fold it. +  return SDValue(); +} + +/// SignBitIsZero - Return true if the sign bit of Op is known to be zero.  We +/// use this predicate to simplify operations downstream. +bool SelectionDAG::SignBitIsZero(SDValue Op, unsigned Depth) const { +  unsigned BitWidth = Op.getScalarValueSizeInBits(); +  return MaskedValueIsZero(Op, APInt::getSignMask(BitWidth), Depth); +} + +/// MaskedValueIsZero - Return true if 'V & Mask' is known to be zero.  We use +/// this predicate to simplify operations downstream.  Mask is known to be zero +/// for bits that V cannot have. +bool SelectionDAG::MaskedValueIsZero(SDValue Op, const APInt &Mask, +                                     unsigned Depth) const { +  KnownBits Known; +  computeKnownBits(Op, Known, Depth); +  return Mask.isSubsetOf(Known.Zero); +} + +/// If a SHL/SRA/SRL node has a constant or splat constant shift amount that +/// is less than the element bit-width of the shift node, return it. +static const APInt *getValidShiftAmountConstant(SDValue V) { +  if (ConstantSDNode *SA = isConstOrConstSplat(V.getOperand(1))) { +    // Shifting more than the bitwidth is not valid. +    const APInt &ShAmt = SA->getAPIntValue(); +    if (ShAmt.ult(V.getScalarValueSizeInBits())) +      return &ShAmt; +  } +  return nullptr; +} + +/// Determine which bits of Op are known to be either zero or one and return +/// them in Known. For vectors, the known bits are those that are shared by +/// every vector element. +void SelectionDAG::computeKnownBits(SDValue Op, KnownBits &Known, +                                    unsigned Depth) const { +  EVT VT = Op.getValueType(); +  APInt DemandedElts = VT.isVector() +                           ? APInt::getAllOnesValue(VT.getVectorNumElements()) +                           : APInt(1, 1); +  computeKnownBits(Op, Known, DemandedElts, Depth); +} + +/// Determine which bits of Op are known to be either zero or one and return +/// them in Known. The DemandedElts argument allows us to only collect the known +/// bits that are shared by the requested vector elements. +void SelectionDAG::computeKnownBits(SDValue Op, KnownBits &Known, +                                    const APInt &DemandedElts, +                                    unsigned Depth) const { +  unsigned BitWidth = Op.getScalarValueSizeInBits(); + +  Known = KnownBits(BitWidth);   // Don't know anything. +  if (Depth == 6) +    return;  // Limit search depth. + +  KnownBits Known2; +  unsigned NumElts = DemandedElts.getBitWidth(); + +  if (!DemandedElts) +    return;  // No demanded elts, better to assume we don't know anything. + +  unsigned Opcode = Op.getOpcode(); +  switch (Opcode) { +  case ISD::Constant: +    // We know all of the bits for a constant! +    Known.One = cast<ConstantSDNode>(Op)->getAPIntValue(); +    Known.Zero = ~Known.One; +    break; +  case ISD::BUILD_VECTOR: +    // Collect the known bits that are shared by every demanded vector element. +    assert(NumElts == Op.getValueType().getVectorNumElements() && +           "Unexpected vector size"); +    Known.Zero.setAllBits(); Known.One.setAllBits(); +    for (unsigned i = 0, e = Op.getNumOperands(); i != e; ++i) { +      if (!DemandedElts[i]) +        continue; + +      SDValue SrcOp = Op.getOperand(i); +      computeKnownBits(SrcOp, Known2, Depth + 1); + +      // BUILD_VECTOR can implicitly truncate sources, we must handle this. +      if (SrcOp.getValueSizeInBits() != BitWidth) { +        assert(SrcOp.getValueSizeInBits() > BitWidth && +               "Expected BUILD_VECTOR implicit truncation"); +        Known2 = Known2.trunc(BitWidth); +      } + +      // Known bits are the values that are shared by every demanded element. +      Known.One &= Known2.One; +      Known.Zero &= Known2.Zero; + +      // If we don't know any bits, early out. +      if (!Known.One && !Known.Zero) +        break; +    } +    break; +  case ISD::VECTOR_SHUFFLE: { +    // Collect the known bits that are shared by every vector element referenced +    // by the shuffle. +    APInt DemandedLHS(NumElts, 0), DemandedRHS(NumElts, 0); +    Known.Zero.setAllBits(); Known.One.setAllBits(); +    const ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op); +    assert(NumElts == SVN->getMask().size() && "Unexpected vector size"); +    for (unsigned i = 0; i != NumElts; ++i) { +      if (!DemandedElts[i]) +        continue; + +      int M = SVN->getMaskElt(i); +      if (M < 0) { +        // For UNDEF elements, we don't know anything about the common state of +        // the shuffle result. +        Known.resetAll(); +        DemandedLHS.clearAllBits(); +        DemandedRHS.clearAllBits(); +        break; +      } + +      if ((unsigned)M < NumElts) +        DemandedLHS.setBit((unsigned)M % NumElts); +      else +        DemandedRHS.setBit((unsigned)M % NumElts); +    } +    // Known bits are the values that are shared by every demanded element. +    if (!!DemandedLHS) { +      SDValue LHS = Op.getOperand(0); +      computeKnownBits(LHS, Known2, DemandedLHS, Depth + 1); +      Known.One &= Known2.One; +      Known.Zero &= Known2.Zero; +    } +    // If we don't know any bits, early out. +    if (!Known.One && !Known.Zero) +      break; +    if (!!DemandedRHS) { +      SDValue RHS = Op.getOperand(1); +      computeKnownBits(RHS, Known2, DemandedRHS, Depth + 1); +      Known.One &= Known2.One; +      Known.Zero &= Known2.Zero; +    } +    break; +  } +  case ISD::CONCAT_VECTORS: { +    // Split DemandedElts and test each of the demanded subvectors. +    Known.Zero.setAllBits(); Known.One.setAllBits(); +    EVT SubVectorVT = Op.getOperand(0).getValueType(); +    unsigned NumSubVectorElts = SubVectorVT.getVectorNumElements(); +    unsigned NumSubVectors = Op.getNumOperands(); +    for (unsigned i = 0; i != NumSubVectors; ++i) { +      APInt DemandedSub = DemandedElts.lshr(i * NumSubVectorElts); +      DemandedSub = DemandedSub.trunc(NumSubVectorElts); +      if (!!DemandedSub) { +        SDValue Sub = Op.getOperand(i); +        computeKnownBits(Sub, Known2, DemandedSub, Depth + 1); +        Known.One &= Known2.One; +        Known.Zero &= Known2.Zero; +      } +      // If we don't know any bits, early out. +      if (!Known.One && !Known.Zero) +        break; +    } +    break; +  } +  case ISD::EXTRACT_SUBVECTOR: { +    // If we know the element index, just demand that subvector elements, +    // otherwise demand them all. +    SDValue Src = Op.getOperand(0); +    ConstantSDNode *SubIdx = dyn_cast<ConstantSDNode>(Op.getOperand(1)); +    unsigned NumSrcElts = Src.getValueType().getVectorNumElements(); +    if (SubIdx && SubIdx->getAPIntValue().ule(NumSrcElts - NumElts)) { +      // Offset the demanded elts by the subvector index. +      uint64_t Idx = SubIdx->getZExtValue(); +      APInt DemandedSrc = DemandedElts.zext(NumSrcElts).shl(Idx); +      computeKnownBits(Src, Known, DemandedSrc, Depth + 1); +    } else { +      computeKnownBits(Src, Known, Depth + 1); +    } +    break; +  } +  case ISD::BITCAST: { +    SDValue N0 = Op.getOperand(0); +    unsigned SubBitWidth = N0.getScalarValueSizeInBits(); + +    // Ignore bitcasts from floating point. +    if (!N0.getValueType().isInteger()) +      break; + +    // Fast handling of 'identity' bitcasts. +    if (BitWidth == SubBitWidth) { +      computeKnownBits(N0, Known, DemandedElts, Depth + 1); +      break; +    } + +    // Support big-endian targets when it becomes useful. +    bool IsLE = getDataLayout().isLittleEndian(); +    if (!IsLE) +      break; + +    // Bitcast 'small element' vector to 'large element' scalar/vector. +    if ((BitWidth % SubBitWidth) == 0) { +      assert(N0.getValueType().isVector() && "Expected bitcast from vector"); + +      // Collect known bits for the (larger) output by collecting the known +      // bits from each set of sub elements and shift these into place. +      // We need to separately call computeKnownBits for each set of +      // sub elements as the knownbits for each is likely to be different. +      unsigned SubScale = BitWidth / SubBitWidth; +      APInt SubDemandedElts(NumElts * SubScale, 0); +      for (unsigned i = 0; i != NumElts; ++i) +        if (DemandedElts[i]) +          SubDemandedElts.setBit(i * SubScale); + +      for (unsigned i = 0; i != SubScale; ++i) { +        computeKnownBits(N0, Known2, SubDemandedElts.shl(i), +                         Depth + 1); +        Known.One |= Known2.One.zext(BitWidth).shl(SubBitWidth * i); +        Known.Zero |= Known2.Zero.zext(BitWidth).shl(SubBitWidth * i); +      } +    } + +    // Bitcast 'large element' scalar/vector to 'small element' vector. +    if ((SubBitWidth % BitWidth) == 0) { +      assert(Op.getValueType().isVector() && "Expected bitcast to vector"); + +      // Collect known bits for the (smaller) output by collecting the known +      // bits from the overlapping larger input elements and extracting the +      // sub sections we actually care about. +      unsigned SubScale = SubBitWidth / BitWidth; +      APInt SubDemandedElts(NumElts / SubScale, 0); +      for (unsigned i = 0; i != NumElts; ++i) +        if (DemandedElts[i]) +          SubDemandedElts.setBit(i / SubScale); + +      computeKnownBits(N0, Known2, SubDemandedElts, Depth + 1); + +      Known.Zero.setAllBits(); Known.One.setAllBits(); +      for (unsigned i = 0; i != NumElts; ++i) +        if (DemandedElts[i]) { +          unsigned Offset = (i % SubScale) * BitWidth; +          Known.One &= Known2.One.lshr(Offset).trunc(BitWidth); +          Known.Zero &= Known2.Zero.lshr(Offset).trunc(BitWidth); +          // If we don't know any bits, early out. +          if (!Known.One && !Known.Zero) +            break; +        } +    } +    break; +  } +  case ISD::AND: +    // If either the LHS or the RHS are Zero, the result is zero. +    computeKnownBits(Op.getOperand(1), Known, DemandedElts, Depth + 1); +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); + +    // Output known-1 bits are only known if set in both the LHS & RHS. +    Known.One &= Known2.One; +    // Output known-0 are known to be clear if zero in either the LHS | RHS. +    Known.Zero |= Known2.Zero; +    break; +  case ISD::OR: +    computeKnownBits(Op.getOperand(1), Known, DemandedElts, Depth + 1); +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); + +    // Output known-0 bits are only known if clear in both the LHS & RHS. +    Known.Zero &= Known2.Zero; +    // Output known-1 are known to be set if set in either the LHS | RHS. +    Known.One |= Known2.One; +    break; +  case ISD::XOR: { +    computeKnownBits(Op.getOperand(1), Known, DemandedElts, Depth + 1); +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); + +    // Output known-0 bits are known if clear or set in both the LHS & RHS. +    APInt KnownZeroOut = (Known.Zero & Known2.Zero) | (Known.One & Known2.One); +    // Output known-1 are known to be set if set in only one of the LHS, RHS. +    Known.One = (Known.Zero & Known2.One) | (Known.One & Known2.Zero); +    Known.Zero = KnownZeroOut; +    break; +  } +  case ISD::MUL: { +    computeKnownBits(Op.getOperand(1), Known, DemandedElts, Depth + 1); +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); + +    // If low bits are zero in either operand, output low known-0 bits. +    // Also compute a conservative estimate for high known-0 bits. +    // More trickiness is possible, but this is sufficient for the +    // interesting case of alignment computation. +    unsigned TrailZ = Known.countMinTrailingZeros() + +                      Known2.countMinTrailingZeros(); +    unsigned LeadZ =  std::max(Known.countMinLeadingZeros() + +                               Known2.countMinLeadingZeros(), +                               BitWidth) - BitWidth; + +    Known.resetAll(); +    Known.Zero.setLowBits(std::min(TrailZ, BitWidth)); +    Known.Zero.setHighBits(std::min(LeadZ, BitWidth)); +    break; +  } +  case ISD::UDIV: { +    // For the purposes of computing leading zeros we can conservatively +    // treat a udiv as a logical right shift by the power of 2 known to +    // be less than the denominator. +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    unsigned LeadZ = Known2.countMinLeadingZeros(); + +    computeKnownBits(Op.getOperand(1), Known2, DemandedElts, Depth + 1); +    unsigned RHSMaxLeadingZeros = Known2.countMaxLeadingZeros(); +    if (RHSMaxLeadingZeros != BitWidth) +      LeadZ = std::min(BitWidth, LeadZ + BitWidth - RHSMaxLeadingZeros - 1); + +    Known.Zero.setHighBits(LeadZ); +    break; +  } +  case ISD::SELECT: +    computeKnownBits(Op.getOperand(2), Known, Depth+1); +    // If we don't know any bits, early out. +    if (!Known.One && !Known.Zero) +      break; +    computeKnownBits(Op.getOperand(1), Known2, Depth+1); + +    // Only known if known in both the LHS and RHS. +    Known.One &= Known2.One; +    Known.Zero &= Known2.Zero; +    break; +  case ISD::SELECT_CC: +    computeKnownBits(Op.getOperand(3), Known, Depth+1); +    // If we don't know any bits, early out. +    if (!Known.One && !Known.Zero) +      break; +    computeKnownBits(Op.getOperand(2), Known2, Depth+1); + +    // Only known if known in both the LHS and RHS. +    Known.One &= Known2.One; +    Known.Zero &= Known2.Zero; +    break; +  case ISD::SMULO: +  case ISD::UMULO: +    if (Op.getResNo() != 1) +      break; +    // The boolean result conforms to getBooleanContents. +    // If we know the result of a setcc has the top bits zero, use this info. +    // We know that we have an integer-based boolean since these operations +    // are only available for integer. +    if (TLI->getBooleanContents(Op.getValueType().isVector(), false) == +            TargetLowering::ZeroOrOneBooleanContent && +        BitWidth > 1) +      Known.Zero.setBitsFrom(1); +    break; +  case ISD::SETCC: +    // If we know the result of a setcc has the top bits zero, use this info. +    if (TLI->getBooleanContents(Op.getOperand(0).getValueType()) == +            TargetLowering::ZeroOrOneBooleanContent && +        BitWidth > 1) +      Known.Zero.setBitsFrom(1); +    break; +  case ISD::SHL: +    if (const APInt *ShAmt = getValidShiftAmountConstant(Op)) { +      computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +      Known.Zero <<= *ShAmt; +      Known.One <<= *ShAmt; +      // Low bits are known zero. +      Known.Zero.setLowBits(ShAmt->getZExtValue()); +    } +    break; +  case ISD::SRL: +    if (const APInt *ShAmt = getValidShiftAmountConstant(Op)) { +      computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +      Known.Zero.lshrInPlace(*ShAmt); +      Known.One.lshrInPlace(*ShAmt); +      // High bits are known zero. +      Known.Zero.setHighBits(ShAmt->getZExtValue()); +    } +    break; +  case ISD::SRA: +    if (const APInt *ShAmt = getValidShiftAmountConstant(Op)) { +      computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +      Known.Zero.lshrInPlace(*ShAmt); +      Known.One.lshrInPlace(*ShAmt); +      // If we know the value of the sign bit, then we know it is copied across +      // the high bits by the shift amount. +      APInt SignMask = APInt::getSignMask(BitWidth); +      SignMask.lshrInPlace(*ShAmt);  // Adjust to where it is now in the mask. +      if (Known.Zero.intersects(SignMask)) { +        Known.Zero.setHighBits(ShAmt->getZExtValue());// New bits are known zero. +      } else if (Known.One.intersects(SignMask)) { +        Known.One.setHighBits(ShAmt->getZExtValue()); // New bits are known one. +      } +    } +    break; +  case ISD::SIGN_EXTEND_INREG: { +    EVT EVT = cast<VTSDNode>(Op.getOperand(1))->getVT(); +    unsigned EBits = EVT.getScalarSizeInBits(); + +    // Sign extension.  Compute the demanded bits in the result that are not +    // present in the input. +    APInt NewBits = APInt::getHighBitsSet(BitWidth, BitWidth - EBits); + +    APInt InSignMask = APInt::getSignMask(EBits); +    APInt InputDemandedBits = APInt::getLowBitsSet(BitWidth, EBits); + +    // If the sign extended bits are demanded, we know that the sign +    // bit is demanded. +    InSignMask = InSignMask.zext(BitWidth); +    if (NewBits.getBoolValue()) +      InputDemandedBits |= InSignMask; + +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +    Known.One &= InputDemandedBits; +    Known.Zero &= InputDemandedBits; + +    // If the sign bit of the input is known set or clear, then we know the +    // top bits of the result. +    if (Known.Zero.intersects(InSignMask)) {        // Input sign bit known clear +      Known.Zero |= NewBits; +      Known.One  &= ~NewBits; +    } else if (Known.One.intersects(InSignMask)) {  // Input sign bit known set +      Known.One  |= NewBits; +      Known.Zero &= ~NewBits; +    } else {                              // Input sign bit unknown +      Known.Zero &= ~NewBits; +      Known.One  &= ~NewBits; +    } +    break; +  } +  case ISD::CTTZ: +  case ISD::CTTZ_ZERO_UNDEF: { +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    // If we have a known 1, its position is our upper bound. +    unsigned PossibleTZ = Known2.countMaxTrailingZeros(); +    unsigned LowBits = Log2_32(PossibleTZ) + 1; +    Known.Zero.setBitsFrom(LowBits); +    break; +  } +  case ISD::CTLZ: +  case ISD::CTLZ_ZERO_UNDEF: { +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    // If we have a known 1, its position is our upper bound. +    unsigned PossibleLZ = Known2.countMaxLeadingZeros(); +    unsigned LowBits = Log2_32(PossibleLZ) + 1; +    Known.Zero.setBitsFrom(LowBits); +    break; +  } +  case ISD::CTPOP: { +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    // If we know some of the bits are zero, they can't be one. +    unsigned PossibleOnes = Known2.countMaxPopulation(); +    Known.Zero.setBitsFrom(Log2_32(PossibleOnes) + 1); +    break; +  } +  case ISD::LOAD: { +    LoadSDNode *LD = cast<LoadSDNode>(Op); +    // If this is a ZEXTLoad and we are looking at the loaded value. +    if (ISD::isZEXTLoad(Op.getNode()) && Op.getResNo() == 0) { +      EVT VT = LD->getMemoryVT(); +      unsigned MemBits = VT.getScalarSizeInBits(); +      Known.Zero.setBitsFrom(MemBits); +    } else if (const MDNode *Ranges = LD->getRanges()) { +      if (LD->getExtensionType() == ISD::NON_EXTLOAD) +        computeKnownBitsFromRangeMetadata(*Ranges, Known); +    } +    break; +  } +  case ISD::ZERO_EXTEND_VECTOR_INREG: { +    EVT InVT = Op.getOperand(0).getValueType(); +    unsigned InBits = InVT.getScalarSizeInBits(); +    Known = Known.trunc(InBits); +    computeKnownBits(Op.getOperand(0), Known, +                     DemandedElts.zext(InVT.getVectorNumElements()), +                     Depth + 1); +    Known = Known.zext(BitWidth); +    Known.Zero.setBitsFrom(InBits); +    break; +  } +  case ISD::ZERO_EXTEND: { +    EVT InVT = Op.getOperand(0).getValueType(); +    unsigned InBits = InVT.getScalarSizeInBits(); +    Known = Known.trunc(InBits); +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +    Known = Known.zext(BitWidth); +    Known.Zero.setBitsFrom(InBits); +    break; +  } +  // TODO ISD::SIGN_EXTEND_VECTOR_INREG +  case ISD::SIGN_EXTEND: { +    EVT InVT = Op.getOperand(0).getValueType(); +    unsigned InBits = InVT.getScalarSizeInBits(); + +    Known = Known.trunc(InBits); +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); + +    // If the sign bit is known to be zero or one, then sext will extend +    // it to the top bits, else it will just zext. +    Known = Known.sext(BitWidth); +    break; +  } +  case ISD::ANY_EXTEND: { +    EVT InVT = Op.getOperand(0).getValueType(); +    unsigned InBits = InVT.getScalarSizeInBits(); +    Known = Known.trunc(InBits); +    computeKnownBits(Op.getOperand(0), Known, Depth+1); +    Known = Known.zext(BitWidth); +    break; +  } +  case ISD::TRUNCATE: { +    EVT InVT = Op.getOperand(0).getValueType(); +    unsigned InBits = InVT.getScalarSizeInBits(); +    Known = Known.zext(InBits); +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +    Known = Known.trunc(BitWidth); +    break; +  } +  case ISD::AssertZext: { +    EVT VT = cast<VTSDNode>(Op.getOperand(1))->getVT(); +    APInt InMask = APInt::getLowBitsSet(BitWidth, VT.getSizeInBits()); +    computeKnownBits(Op.getOperand(0), Known, Depth+1); +    Known.Zero |= (~InMask); +    Known.One  &= (~Known.Zero); +    break; +  } +  case ISD::FGETSIGN: +    // All bits are zero except the low bit. +    Known.Zero.setBitsFrom(1); +    break; +  case ISD::USUBO: +  case ISD::SSUBO: +    if (Op.getResNo() == 1) { +      // If we know the result of a setcc has the top bits zero, use this info. +      if (TLI->getBooleanContents(Op.getOperand(0).getValueType()) == +              TargetLowering::ZeroOrOneBooleanContent && +          BitWidth > 1) +        Known.Zero.setBitsFrom(1); +      break; +    } +    LLVM_FALLTHROUGH; +  case ISD::SUB: +  case ISD::SUBC: { +    if (ConstantSDNode *CLHS = isConstOrConstSplat(Op.getOperand(0))) { +      // We know that the top bits of C-X are clear if X contains less bits +      // than C (i.e. no wrap-around can happen).  For example, 20-X is +      // positive if we can prove that X is >= 0 and < 16. +      if (CLHS->getAPIntValue().isNonNegative()) { +        unsigned NLZ = (CLHS->getAPIntValue()+1).countLeadingZeros(); +        // NLZ can't be BitWidth with no sign bit +        APInt MaskV = APInt::getHighBitsSet(BitWidth, NLZ+1); +        computeKnownBits(Op.getOperand(1), Known2, DemandedElts, +                         Depth + 1); + +        // If all of the MaskV bits are known to be zero, then we know the +        // output top bits are zero, because we now know that the output is +        // from [0-C]. +        if ((Known2.Zero & MaskV) == MaskV) { +          unsigned NLZ2 = CLHS->getAPIntValue().countLeadingZeros(); +          // Top bits known zero. +          Known.Zero.setHighBits(NLZ2); +        } +      } +    } + +    // If low bits are know to be zero in both operands, then we know they are +    // going to be 0 in the result. Both addition and complement operations +    // preserve the low zero bits. +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    unsigned KnownZeroLow = Known2.countMinTrailingZeros(); +    if (KnownZeroLow == 0) +      break; + +    computeKnownBits(Op.getOperand(1), Known2, DemandedElts, Depth + 1); +    KnownZeroLow = std::min(KnownZeroLow, Known2.countMinTrailingZeros()); +    Known.Zero.setLowBits(KnownZeroLow); +    break; +  } +  case ISD::UADDO: +  case ISD::SADDO: +  case ISD::ADDCARRY: +    if (Op.getResNo() == 1) { +      // If we know the result of a setcc has the top bits zero, use this info. +      if (TLI->getBooleanContents(Op.getOperand(0).getValueType()) == +              TargetLowering::ZeroOrOneBooleanContent && +          BitWidth > 1) +        Known.Zero.setBitsFrom(1); +      break; +    } +    LLVM_FALLTHROUGH; +  case ISD::ADD: +  case ISD::ADDC: +  case ISD::ADDE: { +    // Output known-0 bits are known if clear or set in both the low clear bits +    // common to both LHS & RHS.  For example, 8+(X<<3) is known to have the +    // low 3 bits clear. +    // Output known-0 bits are also known if the top bits of each input are +    // known to be clear. For example, if one input has the top 10 bits clear +    // and the other has the top 8 bits clear, we know the top 7 bits of the +    // output must be clear. +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    unsigned KnownZeroHigh = Known2.countMinLeadingZeros(); +    unsigned KnownZeroLow = Known2.countMinTrailingZeros(); + +    computeKnownBits(Op.getOperand(1), Known2, DemandedElts, +                     Depth + 1); +    KnownZeroHigh = std::min(KnownZeroHigh, Known2.countMinLeadingZeros()); +    KnownZeroLow = std::min(KnownZeroLow, Known2.countMinTrailingZeros()); + +    if (Opcode == ISD::ADDE || Opcode == ISD::ADDCARRY) { +      // With ADDE and ADDCARRY, a carry bit may be added in, so we can only +      // use this information if we know (at least) that the low two bits are +      // clear. We then return to the caller that the low bit is unknown but +      // that other bits are known zero. +      if (KnownZeroLow >= 2) +        Known.Zero.setBits(1, KnownZeroLow); +      break; +    } + +    Known.Zero.setLowBits(KnownZeroLow); +    if (KnownZeroHigh > 1) +      Known.Zero.setHighBits(KnownZeroHigh - 1); +    break; +  } +  case ISD::SREM: +    if (ConstantSDNode *Rem = isConstOrConstSplat(Op.getOperand(1))) { +      const APInt &RA = Rem->getAPIntValue().abs(); +      if (RA.isPowerOf2()) { +        APInt LowBits = RA - 1; +        computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); + +        // The low bits of the first operand are unchanged by the srem. +        Known.Zero = Known2.Zero & LowBits; +        Known.One = Known2.One & LowBits; + +        // If the first operand is non-negative or has all low bits zero, then +        // the upper bits are all zero. +        if (Known2.Zero[BitWidth-1] || ((Known2.Zero & LowBits) == LowBits)) +          Known.Zero |= ~LowBits; + +        // If the first operand is negative and not all low bits are zero, then +        // the upper bits are all one. +        if (Known2.One[BitWidth-1] && ((Known2.One & LowBits) != 0)) +          Known.One |= ~LowBits; +        assert((Known.Zero & Known.One) == 0&&"Bits known to be one AND zero?"); +      } +    } +    break; +  case ISD::UREM: { +    if (ConstantSDNode *Rem = isConstOrConstSplat(Op.getOperand(1))) { +      const APInt &RA = Rem->getAPIntValue(); +      if (RA.isPowerOf2()) { +        APInt LowBits = (RA - 1); +        computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); + +        // The upper bits are all zero, the lower ones are unchanged. +        Known.Zero = Known2.Zero | ~LowBits; +        Known.One = Known2.One & LowBits; +        break; +      } +    } + +    // Since the result is less than or equal to either operand, any leading +    // zero bits in either operand must also exist in the result. +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +    computeKnownBits(Op.getOperand(1), Known2, DemandedElts, Depth + 1); + +    uint32_t Leaders = +        std::max(Known.countMinLeadingZeros(), Known2.countMinLeadingZeros()); +    Known.resetAll(); +    Known.Zero.setHighBits(Leaders); +    break; +  } +  case ISD::EXTRACT_ELEMENT: { +    computeKnownBits(Op.getOperand(0), Known, Depth+1); +    const unsigned Index = Op.getConstantOperandVal(1); +    const unsigned BitWidth = Op.getValueSizeInBits(); + +    // Remove low part of known bits mask +    Known.Zero = Known.Zero.getHiBits(Known.Zero.getBitWidth() - Index * BitWidth); +    Known.One = Known.One.getHiBits(Known.One.getBitWidth() - Index * BitWidth); + +    // Remove high part of known bit mask +    Known = Known.trunc(BitWidth); +    break; +  } +  case ISD::EXTRACT_VECTOR_ELT: { +    SDValue InVec = Op.getOperand(0); +    SDValue EltNo = Op.getOperand(1); +    EVT VecVT = InVec.getValueType(); +    const unsigned BitWidth = Op.getValueSizeInBits(); +    const unsigned EltBitWidth = VecVT.getScalarSizeInBits(); +    const unsigned NumSrcElts = VecVT.getVectorNumElements(); +    // If BitWidth > EltBitWidth the value is anyext:ed. So we do not know +    // anything about the extended bits. +    if (BitWidth > EltBitWidth) +      Known = Known.trunc(EltBitWidth); +    ConstantSDNode *ConstEltNo = dyn_cast<ConstantSDNode>(EltNo); +    if (ConstEltNo && ConstEltNo->getAPIntValue().ult(NumSrcElts)) { +      // If we know the element index, just demand that vector element. +      unsigned Idx = ConstEltNo->getZExtValue(); +      APInt DemandedElt = APInt::getOneBitSet(NumSrcElts, Idx); +      computeKnownBits(InVec, Known, DemandedElt, Depth + 1); +    } else { +      // Unknown element index, so ignore DemandedElts and demand them all. +      computeKnownBits(InVec, Known, Depth + 1); +    } +    if (BitWidth > EltBitWidth) +      Known = Known.zext(BitWidth); +    break; +  } +  case ISD::INSERT_VECTOR_ELT: { +    SDValue InVec = Op.getOperand(0); +    SDValue InVal = Op.getOperand(1); +    SDValue EltNo = Op.getOperand(2); + +    ConstantSDNode *CEltNo = dyn_cast<ConstantSDNode>(EltNo); +    if (CEltNo && CEltNo->getAPIntValue().ult(NumElts)) { +      // If we know the element index, split the demand between the +      // source vector and the inserted element. +      Known.Zero = Known.One = APInt::getAllOnesValue(BitWidth); +      unsigned EltIdx = CEltNo->getZExtValue(); + +      // If we demand the inserted element then add its common known bits. +      if (DemandedElts[EltIdx]) { +        computeKnownBits(InVal, Known2, Depth + 1); +        Known.One &= Known2.One.zextOrTrunc(Known.One.getBitWidth()); +        Known.Zero &= Known2.Zero.zextOrTrunc(Known.Zero.getBitWidth()); +      } + +      // If we demand the source vector then add its common known bits, ensuring +      // that we don't demand the inserted element. +      APInt VectorElts = DemandedElts & ~(APInt::getOneBitSet(NumElts, EltIdx)); +      if (!!VectorElts) { +        computeKnownBits(InVec, Known2, VectorElts, Depth + 1); +        Known.One &= Known2.One; +        Known.Zero &= Known2.Zero; +      } +    } else { +      // Unknown element index, so ignore DemandedElts and demand them all. +      computeKnownBits(InVec, Known, Depth + 1); +      computeKnownBits(InVal, Known2, Depth + 1); +      Known.One &= Known2.One.zextOrTrunc(Known.One.getBitWidth()); +      Known.Zero &= Known2.Zero.zextOrTrunc(Known.Zero.getBitWidth()); +    } +    break; +  } +  case ISD::BITREVERSE: { +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    Known.Zero = Known2.Zero.reverseBits(); +    Known.One = Known2.One.reverseBits(); +    break; +  } +  case ISD::BSWAP: { +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); +    Known.Zero = Known2.Zero.byteSwap(); +    Known.One = Known2.One.byteSwap(); +    break; +  } +  case ISD::ABS: { +    computeKnownBits(Op.getOperand(0), Known2, DemandedElts, Depth + 1); + +    // If the source's MSB is zero then we know the rest of the bits already. +    if (Known2.isNonNegative()) { +      Known.Zero = Known2.Zero; +      Known.One = Known2.One; +      break; +    } + +    // We only know that the absolute values's MSB will be zero iff there is +    // a set bit that isn't the sign bit (otherwise it could be INT_MIN). +    Known2.One.clearSignBit(); +    if (Known2.One.getBoolValue()) { +      Known.Zero = APInt::getSignMask(BitWidth); +      break; +    } +    break; +  } +  case ISD::UMIN: { +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1); +    computeKnownBits(Op.getOperand(1), Known2, DemandedElts, Depth + 1); + +    // UMIN - we know that the result will have the maximum of the +    // known zero leading bits of the inputs. +    unsigned LeadZero = Known.countMinLeadingZeros(); +    LeadZero = std::max(LeadZero, Known2.countMinLeadingZeros()); + +    Known.Zero &= Known2.Zero; +    Known.One &= Known2.One; +    Known.Zero.setHighBits(LeadZero); +    break; +  } +  case ISD::UMAX: { +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, +                     Depth + 1); +    computeKnownBits(Op.getOperand(1), Known2, DemandedElts, Depth + 1); + +    // UMAX - we know that the result will have the maximum of the +    // known one leading bits of the inputs. +    unsigned LeadOne = Known.countMinLeadingOnes(); +    LeadOne = std::max(LeadOne, Known2.countMinLeadingOnes()); + +    Known.Zero &= Known2.Zero; +    Known.One &= Known2.One; +    Known.One.setHighBits(LeadOne); +    break; +  } +  case ISD::SMIN: +  case ISD::SMAX: { +    computeKnownBits(Op.getOperand(0), Known, DemandedElts, +                     Depth + 1); +    // If we don't know any bits, early out. +    if (!Known.One && !Known.Zero) +      break; +    computeKnownBits(Op.getOperand(1), Known2, DemandedElts, Depth + 1); +    Known.Zero &= Known2.Zero; +    Known.One &= Known2.One; +    break; +  } +  case ISD::FrameIndex: +  case ISD::TargetFrameIndex: +    if (unsigned Align = InferPtrAlignment(Op)) { +      // The low bits are known zero if the pointer is aligned. +      Known.Zero.setLowBits(Log2_32(Align)); +      break; +    } +    break; + +  default: +    if (Opcode < ISD::BUILTIN_OP_END) +      break; +    LLVM_FALLTHROUGH; +  case ISD::INTRINSIC_WO_CHAIN: +  case ISD::INTRINSIC_W_CHAIN: +  case ISD::INTRINSIC_VOID: +    // Allow the target to implement this method for its nodes. +    TLI->computeKnownBitsForTargetNode(Op, Known, DemandedElts, *this, Depth); +    break; +  } + +  assert((Known.Zero & Known.One) == 0 && "Bits known to be one AND zero?"); +} + +SelectionDAG::OverflowKind SelectionDAG::computeOverflowKind(SDValue N0, +                                                             SDValue N1) const { +  // X + 0 never overflow +  if (isNullConstant(N1)) +    return OFK_Never; + +  KnownBits N1Known; +  computeKnownBits(N1, N1Known); +  if (N1Known.Zero.getBoolValue()) { +    KnownBits N0Known; +    computeKnownBits(N0, N0Known); + +    bool overflow; +    (void)(~N0Known.Zero).uadd_ov(~N1Known.Zero, overflow); +    if (!overflow) +      return OFK_Never; +  } + +  // mulhi + 1 never overflow +  if (N0.getOpcode() == ISD::UMUL_LOHI && N0.getResNo() == 1 && +      (~N1Known.Zero & 0x01) == ~N1Known.Zero) +    return OFK_Never; + +  if (N1.getOpcode() == ISD::UMUL_LOHI && N1.getResNo() == 1) { +    KnownBits N0Known; +    computeKnownBits(N0, N0Known); + +    if ((~N0Known.Zero & 0x01) == ~N0Known.Zero) +      return OFK_Never; +  } + +  return OFK_Sometime; +} + +bool SelectionDAG::isKnownToBeAPowerOfTwo(SDValue Val) const { +  EVT OpVT = Val.getValueType(); +  unsigned BitWidth = OpVT.getScalarSizeInBits(); + +  // Is the constant a known power of 2? +  if (ConstantSDNode *Const = dyn_cast<ConstantSDNode>(Val)) +    return Const->getAPIntValue().zextOrTrunc(BitWidth).isPowerOf2(); + +  // A left-shift of a constant one will have exactly one bit set because +  // shifting the bit off the end is undefined. +  if (Val.getOpcode() == ISD::SHL) { +    auto *C = isConstOrConstSplat(Val.getOperand(0)); +    if (C && C->getAPIntValue() == 1) +      return true; +  } + +  // Similarly, a logical right-shift of a constant sign-bit will have exactly +  // one bit set. +  if (Val.getOpcode() == ISD::SRL) { +    auto *C = isConstOrConstSplat(Val.getOperand(0)); +    if (C && C->getAPIntValue().isSignMask()) +      return true; +  } + +  // Are all operands of a build vector constant powers of two? +  if (Val.getOpcode() == ISD::BUILD_VECTOR) +    if (llvm::all_of(Val->ops(), [BitWidth](SDValue E) { +          if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(E)) +            return C->getAPIntValue().zextOrTrunc(BitWidth).isPowerOf2(); +          return false; +        })) +      return true; + +  // More could be done here, though the above checks are enough +  // to handle some common cases. + +  // Fall back to computeKnownBits to catch other known cases. +  KnownBits Known; +  computeKnownBits(Val, Known); +  return (Known.countMaxPopulation() == 1) && (Known.countMinPopulation() == 1); +} + +unsigned SelectionDAG::ComputeNumSignBits(SDValue Op, unsigned Depth) const { +  EVT VT = Op.getValueType(); +  APInt DemandedElts = VT.isVector() +                           ? APInt::getAllOnesValue(VT.getVectorNumElements()) +                           : APInt(1, 1); +  return ComputeNumSignBits(Op, DemandedElts, Depth); +} + +unsigned SelectionDAG::ComputeNumSignBits(SDValue Op, const APInt &DemandedElts, +                                          unsigned Depth) const { +  EVT VT = Op.getValueType(); +  assert(VT.isInteger() && "Invalid VT!"); +  unsigned VTBits = VT.getScalarSizeInBits(); +  unsigned NumElts = DemandedElts.getBitWidth(); +  unsigned Tmp, Tmp2; +  unsigned FirstAnswer = 1; + +  if (Depth == 6) +    return 1;  // Limit search depth. + +  if (!DemandedElts) +    return 1;  // No demanded elts, better to assume we don't know anything. + +  switch (Op.getOpcode()) { +  default: break; +  case ISD::AssertSext: +    Tmp = cast<VTSDNode>(Op.getOperand(1))->getVT().getSizeInBits(); +    return VTBits-Tmp+1; +  case ISD::AssertZext: +    Tmp = cast<VTSDNode>(Op.getOperand(1))->getVT().getSizeInBits(); +    return VTBits-Tmp; + +  case ISD::Constant: { +    const APInt &Val = cast<ConstantSDNode>(Op)->getAPIntValue(); +    return Val.getNumSignBits(); +  } + +  case ISD::BUILD_VECTOR: +    Tmp = VTBits; +    for (unsigned i = 0, e = Op.getNumOperands(); (i < e) && (Tmp > 1); ++i) { +      if (!DemandedElts[i]) +        continue; + +      SDValue SrcOp = Op.getOperand(i); +      Tmp2 = ComputeNumSignBits(Op.getOperand(i), Depth + 1); + +      // BUILD_VECTOR can implicitly truncate sources, we must handle this. +      if (SrcOp.getValueSizeInBits() != VTBits) { +        assert(SrcOp.getValueSizeInBits() > VTBits && +               "Expected BUILD_VECTOR implicit truncation"); +        unsigned ExtraBits = SrcOp.getValueSizeInBits() - VTBits; +        Tmp2 = (Tmp2 > ExtraBits ? Tmp2 - ExtraBits : 1); +      } +      Tmp = std::min(Tmp, Tmp2); +    } +    return Tmp; + +  case ISD::VECTOR_SHUFFLE: { +    // Collect the minimum number of sign bits that are shared by every vector +    // element referenced by the shuffle. +    APInt DemandedLHS(NumElts, 0), DemandedRHS(NumElts, 0); +    const ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op); +    assert(NumElts == SVN->getMask().size() && "Unexpected vector size"); +    for (unsigned i = 0; i != NumElts; ++i) { +      int M = SVN->getMaskElt(i); +      if (!DemandedElts[i]) +        continue; +      // For UNDEF elements, we don't know anything about the common state of +      // the shuffle result. +      if (M < 0) +        return 1; +      if ((unsigned)M < NumElts) +        DemandedLHS.setBit((unsigned)M % NumElts); +      else +        DemandedRHS.setBit((unsigned)M % NumElts); +    } +    Tmp = std::numeric_limits<unsigned>::max(); +    if (!!DemandedLHS) +      Tmp = ComputeNumSignBits(Op.getOperand(0), DemandedLHS, Depth + 1); +    if (!!DemandedRHS) { +      Tmp2 = ComputeNumSignBits(Op.getOperand(1), DemandedRHS, Depth + 1); +      Tmp = std::min(Tmp, Tmp2); +    } +    // If we don't know anything, early out and try computeKnownBits fall-back. +    if (Tmp == 1) +      break; +    assert(Tmp <= VTBits && "Failed to determine minimum sign bits"); +    return Tmp; +  } + +  case ISD::SIGN_EXTEND: +  case ISD::SIGN_EXTEND_VECTOR_INREG: +    Tmp = VTBits - Op.getOperand(0).getScalarValueSizeInBits(); +    return ComputeNumSignBits(Op.getOperand(0), Depth+1) + Tmp; + +  case ISD::SIGN_EXTEND_INREG: +    // Max of the input and what this extends. +    Tmp = cast<VTSDNode>(Op.getOperand(1))->getVT().getScalarSizeInBits(); +    Tmp = VTBits-Tmp+1; + +    Tmp2 = ComputeNumSignBits(Op.getOperand(0), Depth+1); +    return std::max(Tmp, Tmp2); + +  case ISD::SRA: +    Tmp = ComputeNumSignBits(Op.getOperand(0), DemandedElts, Depth+1); +    // SRA X, C   -> adds C sign bits. +    if (ConstantSDNode *C = isConstOrConstSplat(Op.getOperand(1))) { +      APInt ShiftVal = C->getAPIntValue(); +      ShiftVal += Tmp; +      Tmp = ShiftVal.uge(VTBits) ? VTBits : ShiftVal.getZExtValue(); +    } +    return Tmp; +  case ISD::SHL: +    if (ConstantSDNode *C = isConstOrConstSplat(Op.getOperand(1))) { +      // shl destroys sign bits. +      Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1); +      if (C->getAPIntValue().uge(VTBits) ||      // Bad shift. +          C->getAPIntValue().uge(Tmp)) break;    // Shifted all sign bits out. +      return Tmp - C->getZExtValue(); +    } +    break; +  case ISD::AND: +  case ISD::OR: +  case ISD::XOR:    // NOT is handled here. +    // Logical binary ops preserve the number of sign bits at the worst. +    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1); +    if (Tmp != 1) { +      Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1); +      FirstAnswer = std::min(Tmp, Tmp2); +      // We computed what we know about the sign bits as our first +      // answer. Now proceed to the generic code that uses +      // computeKnownBits, and pick whichever answer is better. +    } +    break; + +  case ISD::SELECT: +    Tmp = ComputeNumSignBits(Op.getOperand(1), Depth+1); +    if (Tmp == 1) return 1;  // Early out. +    Tmp2 = ComputeNumSignBits(Op.getOperand(2), Depth+1); +    return std::min(Tmp, Tmp2); +  case ISD::SELECT_CC: +    Tmp = ComputeNumSignBits(Op.getOperand(2), Depth+1); +    if (Tmp == 1) return 1;  // Early out. +    Tmp2 = ComputeNumSignBits(Op.getOperand(3), Depth+1); +    return std::min(Tmp, Tmp2); +  case ISD::SMIN: +  case ISD::SMAX: +  case ISD::UMIN: +  case ISD::UMAX: +    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth + 1); +    if (Tmp == 1) +      return 1;  // Early out. +    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth + 1); +    return std::min(Tmp, Tmp2); +  case ISD::SADDO: +  case ISD::UADDO: +  case ISD::SSUBO: +  case ISD::USUBO: +  case ISD::SMULO: +  case ISD::UMULO: +    if (Op.getResNo() != 1) +      break; +    // The boolean result conforms to getBooleanContents.  Fall through. +    // If setcc returns 0/-1, all bits are sign bits. +    // We know that we have an integer-based boolean since these operations +    // are only available for integer. +    if (TLI->getBooleanContents(Op.getValueType().isVector(), false) == +        TargetLowering::ZeroOrNegativeOneBooleanContent) +      return VTBits; +    break; +  case ISD::SETCC: +    // If setcc returns 0/-1, all bits are sign bits. +    if (TLI->getBooleanContents(Op.getOperand(0).getValueType()) == +        TargetLowering::ZeroOrNegativeOneBooleanContent) +      return VTBits; +    break; +  case ISD::ROTL: +  case ISD::ROTR: +    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { +      unsigned RotAmt = C->getZExtValue() & (VTBits-1); + +      // Handle rotate right by N like a rotate left by 32-N. +      if (Op.getOpcode() == ISD::ROTR) +        RotAmt = (VTBits-RotAmt) & (VTBits-1); + +      // If we aren't rotating out all of the known-in sign bits, return the +      // number that are left.  This handles rotl(sext(x), 1) for example. +      Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1); +      if (Tmp > RotAmt+1) return Tmp-RotAmt; +    } +    break; +  case ISD::ADD: +  case ISD::ADDC: +    // Add can have at most one carry bit.  Thus we know that the output +    // is, at worst, one more bit than the inputs. +    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1); +    if (Tmp == 1) return 1;  // Early out. + +    // Special case decrementing a value (ADD X, -1): +    if (ConstantSDNode *CRHS = dyn_cast<ConstantSDNode>(Op.getOperand(1))) +      if (CRHS->isAllOnesValue()) { +        KnownBits Known; +        computeKnownBits(Op.getOperand(0), Known, Depth+1); + +        // If the input is known to be 0 or 1, the output is 0/-1, which is all +        // sign bits set. +        if ((Known.Zero | 1).isAllOnesValue()) +          return VTBits; + +        // If we are subtracting one from a positive number, there is no carry +        // out of the result. +        if (Known.isNonNegative()) +          return Tmp; +      } + +    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1); +    if (Tmp2 == 1) return 1; +    return std::min(Tmp, Tmp2)-1; + +  case ISD::SUB: +    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1); +    if (Tmp2 == 1) return 1; + +    // Handle NEG. +    if (ConstantSDNode *CLHS = isConstOrConstSplat(Op.getOperand(0))) +      if (CLHS->isNullValue()) { +        KnownBits Known; +        computeKnownBits(Op.getOperand(1), Known, Depth+1); +        // If the input is known to be 0 or 1, the output is 0/-1, which is all +        // sign bits set. +        if ((Known.Zero | 1).isAllOnesValue()) +          return VTBits; + +        // If the input is known to be positive (the sign bit is known clear), +        // the output of the NEG has the same number of sign bits as the input. +        if (Known.isNonNegative()) +          return Tmp2; + +        // Otherwise, we treat this like a SUB. +      } + +    // Sub can have at most one carry bit.  Thus we know that the output +    // is, at worst, one more bit than the inputs. +    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1); +    if (Tmp == 1) return 1;  // Early out. +    return std::min(Tmp, Tmp2)-1; +  case ISD::TRUNCATE: { +    // Check if the sign bits of source go down as far as the truncated value. +    unsigned NumSrcBits = Op.getOperand(0).getScalarValueSizeInBits(); +    unsigned NumSrcSignBits = ComputeNumSignBits(Op.getOperand(0), Depth + 1); +    if (NumSrcSignBits > (NumSrcBits - VTBits)) +      return NumSrcSignBits - (NumSrcBits - VTBits); +    break; +  } +  case ISD::EXTRACT_ELEMENT: { +    const int KnownSign = ComputeNumSignBits(Op.getOperand(0), Depth+1); +    const int BitWidth = Op.getValueSizeInBits(); +    const int Items = Op.getOperand(0).getValueSizeInBits() / BitWidth; + +    // Get reverse index (starting from 1), Op1 value indexes elements from +    // little end. Sign starts at big end. +    const int rIndex = Items - 1 - Op.getConstantOperandVal(1); + +    // If the sign portion ends in our element the subtraction gives correct +    // result. Otherwise it gives either negative or > bitwidth result +    return std::max(std::min(KnownSign - rIndex * BitWidth, BitWidth), 0); +  } +  case ISD::INSERT_VECTOR_ELT: { +    SDValue InVec = Op.getOperand(0); +    SDValue InVal = Op.getOperand(1); +    SDValue EltNo = Op.getOperand(2); +    unsigned NumElts = InVec.getValueType().getVectorNumElements(); + +    ConstantSDNode *CEltNo = dyn_cast<ConstantSDNode>(EltNo); +    if (CEltNo && CEltNo->getAPIntValue().ult(NumElts)) { +      // If we know the element index, split the demand between the +      // source vector and the inserted element. +      unsigned EltIdx = CEltNo->getZExtValue(); + +      // If we demand the inserted element then get its sign bits. +      Tmp = std::numeric_limits<unsigned>::max(); +      if (DemandedElts[EltIdx]) { +        // TODO - handle implicit truncation of inserted elements. +        if (InVal.getScalarValueSizeInBits() != VTBits) +          break; +        Tmp = ComputeNumSignBits(InVal, Depth + 1); +      } + +      // If we demand the source vector then get its sign bits, and determine +      // the minimum. +      APInt VectorElts = DemandedElts; +      VectorElts.clearBit(EltIdx); +      if (!!VectorElts) { +        Tmp2 = ComputeNumSignBits(InVec, VectorElts, Depth + 1); +        Tmp = std::min(Tmp, Tmp2); +      } +    } else { +      // Unknown element index, so ignore DemandedElts and demand them all. +      Tmp = ComputeNumSignBits(InVec, Depth + 1); +      Tmp2 = ComputeNumSignBits(InVal, Depth + 1); +      Tmp = std::min(Tmp, Tmp2); +    } +    assert(Tmp <= VTBits && "Failed to determine minimum sign bits"); +    return Tmp; +  } +  case ISD::EXTRACT_VECTOR_ELT: { +    SDValue InVec = Op.getOperand(0); +    SDValue EltNo = Op.getOperand(1); +    EVT VecVT = InVec.getValueType(); +    const unsigned BitWidth = Op.getValueSizeInBits(); +    const unsigned EltBitWidth = Op.getOperand(0).getScalarValueSizeInBits(); +    const unsigned NumSrcElts = VecVT.getVectorNumElements(); + +    // If BitWidth > EltBitWidth the value is anyext:ed, and we do not know +    // anything about sign bits. But if the sizes match we can derive knowledge +    // about sign bits from the vector operand. +    if (BitWidth != EltBitWidth) +      break; + +    // If we know the element index, just demand that vector element, else for +    // an unknown element index, ignore DemandedElts and demand them all. +    APInt DemandedSrcElts = APInt::getAllOnesValue(NumSrcElts); +    ConstantSDNode *ConstEltNo = dyn_cast<ConstantSDNode>(EltNo); +    if (ConstEltNo && ConstEltNo->getAPIntValue().ult(NumSrcElts)) +      DemandedSrcElts = +          APInt::getOneBitSet(NumSrcElts, ConstEltNo->getZExtValue()); + +    return ComputeNumSignBits(InVec, DemandedSrcElts, Depth + 1); +  } +  case ISD::EXTRACT_SUBVECTOR: { +    // If we know the element index, just demand that subvector elements, +    // otherwise demand them all. +    SDValue Src = Op.getOperand(0); +    ConstantSDNode *SubIdx = dyn_cast<ConstantSDNode>(Op.getOperand(1)); +    unsigned NumSrcElts = Src.getValueType().getVectorNumElements(); +    if (SubIdx && SubIdx->getAPIntValue().ule(NumSrcElts - NumElts)) { +      // Offset the demanded elts by the subvector index. +      uint64_t Idx = SubIdx->getZExtValue(); +      APInt DemandedSrc = DemandedElts.zext(NumSrcElts).shl(Idx); +      return ComputeNumSignBits(Src, DemandedSrc, Depth + 1); +    } +    return ComputeNumSignBits(Src, Depth + 1); +  } +  case ISD::CONCAT_VECTORS: +    // Determine the minimum number of sign bits across all demanded +    // elts of the input vectors. Early out if the result is already 1. +    Tmp = std::numeric_limits<unsigned>::max(); +    EVT SubVectorVT = Op.getOperand(0).getValueType(); +    unsigned NumSubVectorElts = SubVectorVT.getVectorNumElements(); +    unsigned NumSubVectors = Op.getNumOperands(); +    for (unsigned i = 0; (i < NumSubVectors) && (Tmp > 1); ++i) { +      APInt DemandedSub = DemandedElts.lshr(i * NumSubVectorElts); +      DemandedSub = DemandedSub.trunc(NumSubVectorElts); +      if (!DemandedSub) +        continue; +      Tmp2 = ComputeNumSignBits(Op.getOperand(i), DemandedSub, Depth + 1); +      Tmp = std::min(Tmp, Tmp2); +    } +    assert(Tmp <= VTBits && "Failed to determine minimum sign bits"); +    return Tmp; +  } + +  // If we are looking at the loaded value of the SDNode. +  if (Op.getResNo() == 0) { +    // Handle LOADX separately here. EXTLOAD case will fallthrough. +    if (LoadSDNode *LD = dyn_cast<LoadSDNode>(Op)) { +      unsigned ExtType = LD->getExtensionType(); +      switch (ExtType) { +        default: break; +        case ISD::SEXTLOAD:    // '17' bits known +          Tmp = LD->getMemoryVT().getScalarSizeInBits(); +          return VTBits-Tmp+1; +        case ISD::ZEXTLOAD:    // '16' bits known +          Tmp = LD->getMemoryVT().getScalarSizeInBits(); +          return VTBits-Tmp; +      } +    } +  } + +  // Allow the target to implement this method for its nodes. +  if (Op.getOpcode() >= ISD::BUILTIN_OP_END || +      Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN || +      Op.getOpcode() == ISD::INTRINSIC_W_CHAIN || +      Op.getOpcode() == ISD::INTRINSIC_VOID) { +    unsigned NumBits = +        TLI->ComputeNumSignBitsForTargetNode(Op, DemandedElts, *this, Depth); +    if (NumBits > 1) +      FirstAnswer = std::max(FirstAnswer, NumBits); +  } + +  // Finally, if we can prove that the top bits of the result are 0's or 1's, +  // use this information. +  KnownBits Known; +  computeKnownBits(Op, Known, DemandedElts, Depth); + +  APInt Mask; +  if (Known.isNonNegative()) {        // sign bit is 0 +    Mask = Known.Zero; +  } else if (Known.isNegative()) {  // sign bit is 1; +    Mask = Known.One; +  } else { +    // Nothing known. +    return FirstAnswer; +  } + +  // Okay, we know that the sign bit in Mask is set.  Use CLZ to determine +  // the number of identical bits in the top of the input value. +  Mask = ~Mask; +  Mask <<= Mask.getBitWidth()-VTBits; +  // Return # leading zeros.  We use 'min' here in case Val was zero before +  // shifting.  We don't want to return '64' as for an i32 "0". +  return std::max(FirstAnswer, std::min(VTBits, Mask.countLeadingZeros())); +} + +bool SelectionDAG::isBaseWithConstantOffset(SDValue Op) const { +  if ((Op.getOpcode() != ISD::ADD && Op.getOpcode() != ISD::OR) || +      !isa<ConstantSDNode>(Op.getOperand(1))) +    return false; + +  if (Op.getOpcode() == ISD::OR && +      !MaskedValueIsZero(Op.getOperand(0), +                     cast<ConstantSDNode>(Op.getOperand(1))->getAPIntValue())) +    return false; + +  return true; +} + +bool SelectionDAG::isKnownNeverNaN(SDValue Op) const { +  // If we're told that NaNs won't happen, assume they won't. +  if (getTarget().Options.NoNaNsFPMath) +    return true; + +  if (Op->getFlags().hasNoNaNs()) +    return true; + +  // If the value is a constant, we can obviously see if it is a NaN or not. +  if (const ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Op)) +    return !C->getValueAPF().isNaN(); + +  // TODO: Recognize more cases here. + +  return false; +} + +bool SelectionDAG::isKnownNeverZero(SDValue Op) const { +  // If the value is a constant, we can obviously see if it is a zero or not. +  if (const ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Op)) +    return !C->isZero(); + +  // TODO: Recognize more cases here. +  switch (Op.getOpcode()) { +  default: break; +  case ISD::OR: +    if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) +      return !C->isNullValue(); +    break; +  } + +  return false; +} + +bool SelectionDAG::isEqualTo(SDValue A, SDValue B) const { +  // Check the obvious case. +  if (A == B) return true; + +  // For for negative and positive zero. +  if (const ConstantFPSDNode *CA = dyn_cast<ConstantFPSDNode>(A)) +    if (const ConstantFPSDNode *CB = dyn_cast<ConstantFPSDNode>(B)) +      if (CA->isZero() && CB->isZero()) return true; + +  // Otherwise they may not be equal. +  return false; +} + +bool SelectionDAG::haveNoCommonBitsSet(SDValue A, SDValue B) const { +  assert(A.getValueType() == B.getValueType() && +         "Values must have the same type"); +  KnownBits AKnown, BKnown; +  computeKnownBits(A, AKnown); +  computeKnownBits(B, BKnown); +  return (AKnown.Zero | BKnown.Zero).isAllOnesValue(); +} + +static SDValue FoldCONCAT_VECTORS(const SDLoc &DL, EVT VT, +                                  ArrayRef<SDValue> Ops, +                                  SelectionDAG &DAG) { +  assert(!Ops.empty() && "Can't concatenate an empty list of vectors!"); +  assert(llvm::all_of(Ops, +                      [Ops](SDValue Op) { +                        return Ops[0].getValueType() == Op.getValueType(); +                      }) && +         "Concatenation of vectors with inconsistent value types!"); +  assert((Ops.size() * Ops[0].getValueType().getVectorNumElements()) == +             VT.getVectorNumElements() && +         "Incorrect element count in vector concatenation!"); + +  if (Ops.size() == 1) +    return Ops[0]; + +  // Concat of UNDEFs is UNDEF. +  if (llvm::all_of(Ops, [](SDValue Op) { return Op.isUndef(); })) +    return DAG.getUNDEF(VT); + +  // A CONCAT_VECTOR with all UNDEF/BUILD_VECTOR operands can be +  // simplified to one big BUILD_VECTOR. +  // FIXME: Add support for SCALAR_TO_VECTOR as well. +  EVT SVT = VT.getScalarType(); +  SmallVector<SDValue, 16> Elts; +  for (SDValue Op : Ops) { +    EVT OpVT = Op.getValueType(); +    if (Op.isUndef()) +      Elts.append(OpVT.getVectorNumElements(), DAG.getUNDEF(SVT)); +    else if (Op.getOpcode() == ISD::BUILD_VECTOR) +      Elts.append(Op->op_begin(), Op->op_end()); +    else +      return SDValue(); +  } + +  // BUILD_VECTOR requires all inputs to be of the same type, find the +  // maximum type and extend them all. +  for (SDValue Op : Elts) +    SVT = (SVT.bitsLT(Op.getValueType()) ? Op.getValueType() : SVT); + +  if (SVT.bitsGT(VT.getScalarType())) +    for (SDValue &Op : Elts) +      Op = DAG.getTargetLoweringInfo().isZExtFree(Op.getValueType(), SVT) +               ? DAG.getZExtOrTrunc(Op, DL, SVT) +               : DAG.getSExtOrTrunc(Op, DL, SVT); + +  return DAG.getBuildVector(VT, DL, Elts); +} + +/// Gets or creates the specified node. +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT) { +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, Opcode, getVTList(VT), None); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), +                              getVTList(VT)); +  CSEMap.InsertNode(N, IP); + +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, +                              SDValue Operand, const SDNodeFlags Flags) { +  // Constant fold unary operations with an integer constant operand. Even +  // opaque constant will be folded, because the folding of unary operations +  // doesn't create new constants with different values. Nevertheless, the +  // opaque flag is preserved during folding to prevent future folding with +  // other constants. +  if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Operand)) { +    const APInt &Val = C->getAPIntValue(); +    switch (Opcode) { +    default: break; +    case ISD::SIGN_EXTEND: +      return getConstant(Val.sextOrTrunc(VT.getSizeInBits()), DL, VT, +                         C->isTargetOpcode(), C->isOpaque()); +    case ISD::ANY_EXTEND: +    case ISD::ZERO_EXTEND: +    case ISD::TRUNCATE: +      return getConstant(Val.zextOrTrunc(VT.getSizeInBits()), DL, VT, +                         C->isTargetOpcode(), C->isOpaque()); +    case ISD::UINT_TO_FP: +    case ISD::SINT_TO_FP: { +      APFloat apf(EVTToAPFloatSemantics(VT), +                  APInt::getNullValue(VT.getSizeInBits())); +      (void)apf.convertFromAPInt(Val, +                                 Opcode==ISD::SINT_TO_FP, +                                 APFloat::rmNearestTiesToEven); +      return getConstantFP(apf, DL, VT); +    } +    case ISD::BITCAST: +      if (VT == MVT::f16 && C->getValueType(0) == MVT::i16) +        return getConstantFP(APFloat(APFloat::IEEEhalf(), Val), DL, VT); +      if (VT == MVT::f32 && C->getValueType(0) == MVT::i32) +        return getConstantFP(APFloat(APFloat::IEEEsingle(), Val), DL, VT); +      if (VT == MVT::f64 && C->getValueType(0) == MVT::i64) +        return getConstantFP(APFloat(APFloat::IEEEdouble(), Val), DL, VT); +      if (VT == MVT::f128 && C->getValueType(0) == MVT::i128) +        return getConstantFP(APFloat(APFloat::IEEEquad(), Val), DL, VT); +      break; +    case ISD::ABS: +      return getConstant(Val.abs(), DL, VT, C->isTargetOpcode(), +                         C->isOpaque()); +    case ISD::BITREVERSE: +      return getConstant(Val.reverseBits(), DL, VT, C->isTargetOpcode(), +                         C->isOpaque()); +    case ISD::BSWAP: +      return getConstant(Val.byteSwap(), DL, VT, C->isTargetOpcode(), +                         C->isOpaque()); +    case ISD::CTPOP: +      return getConstant(Val.countPopulation(), DL, VT, C->isTargetOpcode(), +                         C->isOpaque()); +    case ISD::CTLZ: +    case ISD::CTLZ_ZERO_UNDEF: +      return getConstant(Val.countLeadingZeros(), DL, VT, C->isTargetOpcode(), +                         C->isOpaque()); +    case ISD::CTTZ: +    case ISD::CTTZ_ZERO_UNDEF: +      return getConstant(Val.countTrailingZeros(), DL, VT, C->isTargetOpcode(), +                         C->isOpaque()); +    case ISD::FP16_TO_FP: { +      bool Ignored; +      APFloat FPV(APFloat::IEEEhalf(), +                  (Val.getBitWidth() == 16) ? Val : Val.trunc(16)); + +      // This can return overflow, underflow, or inexact; we don't care. +      // FIXME need to be more flexible about rounding mode. +      (void)FPV.convert(EVTToAPFloatSemantics(VT), +                        APFloat::rmNearestTiesToEven, &Ignored); +      return getConstantFP(FPV, DL, VT); +    } +    } +  } + +  // Constant fold unary operations with a floating point constant operand. +  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Operand)) { +    APFloat V = C->getValueAPF();    // make copy +    switch (Opcode) { +    case ISD::FNEG: +      V.changeSign(); +      return getConstantFP(V, DL, VT); +    case ISD::FABS: +      V.clearSign(); +      return getConstantFP(V, DL, VT); +    case ISD::FCEIL: { +      APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardPositive); +      if (fs == APFloat::opOK || fs == APFloat::opInexact) +        return getConstantFP(V, DL, VT); +      break; +    } +    case ISD::FTRUNC: { +      APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardZero); +      if (fs == APFloat::opOK || fs == APFloat::opInexact) +        return getConstantFP(V, DL, VT); +      break; +    } +    case ISD::FFLOOR: { +      APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardNegative); +      if (fs == APFloat::opOK || fs == APFloat::opInexact) +        return getConstantFP(V, DL, VT); +      break; +    } +    case ISD::FP_EXTEND: { +      bool ignored; +      // This can return overflow, underflow, or inexact; we don't care. +      // FIXME need to be more flexible about rounding mode. +      (void)V.convert(EVTToAPFloatSemantics(VT), +                      APFloat::rmNearestTiesToEven, &ignored); +      return getConstantFP(V, DL, VT); +    } +    case ISD::FP_TO_SINT: +    case ISD::FP_TO_UINT: { +      bool ignored; +      APSInt IntVal(VT.getSizeInBits(), Opcode == ISD::FP_TO_UINT); +      // FIXME need to be more flexible about rounding mode. +      APFloat::opStatus s = +          V.convertToInteger(IntVal, APFloat::rmTowardZero, &ignored); +      if (s == APFloat::opInvalidOp) // inexact is OK, in fact usual +        break; +      return getConstant(IntVal, DL, VT); +    } +    case ISD::BITCAST: +      if (VT == MVT::i16 && C->getValueType(0) == MVT::f16) +        return getConstant((uint16_t)V.bitcastToAPInt().getZExtValue(), DL, VT); +      else if (VT == MVT::i32 && C->getValueType(0) == MVT::f32) +        return getConstant((uint32_t)V.bitcastToAPInt().getZExtValue(), DL, VT); +      else if (VT == MVT::i64 && C->getValueType(0) == MVT::f64) +        return getConstant(V.bitcastToAPInt().getZExtValue(), DL, VT); +      break; +    case ISD::FP_TO_FP16: { +      bool Ignored; +      // This can return overflow, underflow, or inexact; we don't care. +      // FIXME need to be more flexible about rounding mode. +      (void)V.convert(APFloat::IEEEhalf(), +                      APFloat::rmNearestTiesToEven, &Ignored); +      return getConstant(V.bitcastToAPInt(), DL, VT); +    } +    } +  } + +  // Constant fold unary operations with a vector integer or float operand. +  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(Operand)) { +    if (BV->isConstant()) { +      switch (Opcode) { +      default: +        // FIXME: Entirely reasonable to perform folding of other unary +        // operations here as the need arises. +        break; +      case ISD::FNEG: +      case ISD::FABS: +      case ISD::FCEIL: +      case ISD::FTRUNC: +      case ISD::FFLOOR: +      case ISD::FP_EXTEND: +      case ISD::FP_TO_SINT: +      case ISD::FP_TO_UINT: +      case ISD::TRUNCATE: +      case ISD::UINT_TO_FP: +      case ISD::SINT_TO_FP: +      case ISD::ABS: +      case ISD::BITREVERSE: +      case ISD::BSWAP: +      case ISD::CTLZ: +      case ISD::CTLZ_ZERO_UNDEF: +      case ISD::CTTZ: +      case ISD::CTTZ_ZERO_UNDEF: +      case ISD::CTPOP: { +        SDValue Ops = { Operand }; +        if (SDValue Fold = FoldConstantVectorArithmetic(Opcode, DL, VT, Ops)) +          return Fold; +      } +      } +    } +  } + +  unsigned OpOpcode = Operand.getNode()->getOpcode(); +  switch (Opcode) { +  case ISD::TokenFactor: +  case ISD::MERGE_VALUES: +  case ISD::CONCAT_VECTORS: +    return Operand;         // Factor, merge or concat of one node?  No need. +  case ISD::FP_ROUND: llvm_unreachable("Invalid method to make FP_ROUND node"); +  case ISD::FP_EXTEND: +    assert(VT.isFloatingPoint() && +           Operand.getValueType().isFloatingPoint() && "Invalid FP cast!"); +    if (Operand.getValueType() == VT) return Operand;  // noop conversion. +    assert((!VT.isVector() || +            VT.getVectorNumElements() == +            Operand.getValueType().getVectorNumElements()) && +           "Vector element count mismatch!"); +    assert(Operand.getValueType().bitsLT(VT) && +           "Invalid fpext node, dst < src!"); +    if (Operand.isUndef()) +      return getUNDEF(VT); +    break; +  case ISD::SIGN_EXTEND: +    assert(VT.isInteger() && Operand.getValueType().isInteger() && +           "Invalid SIGN_EXTEND!"); +    if (Operand.getValueType() == VT) return Operand;   // noop extension +    assert((!VT.isVector() || +            VT.getVectorNumElements() == +            Operand.getValueType().getVectorNumElements()) && +           "Vector element count mismatch!"); +    assert(Operand.getValueType().bitsLT(VT) && +           "Invalid sext node, dst < src!"); +    if (OpOpcode == ISD::SIGN_EXTEND || OpOpcode == ISD::ZERO_EXTEND) +      return getNode(OpOpcode, DL, VT, Operand.getOperand(0)); +    else if (OpOpcode == ISD::UNDEF) +      // sext(undef) = 0, because the top bits will all be the same. +      return getConstant(0, DL, VT); +    break; +  case ISD::ZERO_EXTEND: +    assert(VT.isInteger() && Operand.getValueType().isInteger() && +           "Invalid ZERO_EXTEND!"); +    if (Operand.getValueType() == VT) return Operand;   // noop extension +    assert((!VT.isVector() || +            VT.getVectorNumElements() == +            Operand.getValueType().getVectorNumElements()) && +           "Vector element count mismatch!"); +    assert(Operand.getValueType().bitsLT(VT) && +           "Invalid zext node, dst < src!"); +    if (OpOpcode == ISD::ZERO_EXTEND)   // (zext (zext x)) -> (zext x) +      return getNode(ISD::ZERO_EXTEND, DL, VT, Operand.getOperand(0)); +    else if (OpOpcode == ISD::UNDEF) +      // zext(undef) = 0, because the top bits will be zero. +      return getConstant(0, DL, VT); +    break; +  case ISD::ANY_EXTEND: +    assert(VT.isInteger() && Operand.getValueType().isInteger() && +           "Invalid ANY_EXTEND!"); +    if (Operand.getValueType() == VT) return Operand;   // noop extension +    assert((!VT.isVector() || +            VT.getVectorNumElements() == +            Operand.getValueType().getVectorNumElements()) && +           "Vector element count mismatch!"); +    assert(Operand.getValueType().bitsLT(VT) && +           "Invalid anyext node, dst < src!"); + +    if (OpOpcode == ISD::ZERO_EXTEND || OpOpcode == ISD::SIGN_EXTEND || +        OpOpcode == ISD::ANY_EXTEND) +      // (ext (zext x)) -> (zext x)  and  (ext (sext x)) -> (sext x) +      return getNode(OpOpcode, DL, VT, Operand.getOperand(0)); +    else if (OpOpcode == ISD::UNDEF) +      return getUNDEF(VT); + +    // (ext (trunx x)) -> x +    if (OpOpcode == ISD::TRUNCATE) { +      SDValue OpOp = Operand.getOperand(0); +      if (OpOp.getValueType() == VT) +        return OpOp; +    } +    break; +  case ISD::TRUNCATE: +    assert(VT.isInteger() && Operand.getValueType().isInteger() && +           "Invalid TRUNCATE!"); +    if (Operand.getValueType() == VT) return Operand;   // noop truncate +    assert((!VT.isVector() || +            VT.getVectorNumElements() == +            Operand.getValueType().getVectorNumElements()) && +           "Vector element count mismatch!"); +    assert(Operand.getValueType().bitsGT(VT) && +           "Invalid truncate node, src < dst!"); +    if (OpOpcode == ISD::TRUNCATE) +      return getNode(ISD::TRUNCATE, DL, VT, Operand.getOperand(0)); +    if (OpOpcode == ISD::ZERO_EXTEND || OpOpcode == ISD::SIGN_EXTEND || +        OpOpcode == ISD::ANY_EXTEND) { +      // If the source is smaller than the dest, we still need an extend. +      if (Operand.getOperand(0).getValueType().getScalarType() +            .bitsLT(VT.getScalarType())) +        return getNode(OpOpcode, DL, VT, Operand.getOperand(0)); +      if (Operand.getOperand(0).getValueType().bitsGT(VT)) +        return getNode(ISD::TRUNCATE, DL, VT, Operand.getOperand(0)); +      return Operand.getOperand(0); +    } +    if (OpOpcode == ISD::UNDEF) +      return getUNDEF(VT); +    break; +  case ISD::ABS: +    assert(VT.isInteger() && VT == Operand.getValueType() && +           "Invalid ABS!"); +    if (OpOpcode == ISD::UNDEF) +      return getUNDEF(VT); +    break; +  case ISD::BSWAP: +    assert(VT.isInteger() && VT == Operand.getValueType() && +           "Invalid BSWAP!"); +    assert((VT.getScalarSizeInBits() % 16 == 0) && +           "BSWAP types must be a multiple of 16 bits!"); +    if (OpOpcode == ISD::UNDEF) +      return getUNDEF(VT); +    break; +  case ISD::BITREVERSE: +    assert(VT.isInteger() && VT == Operand.getValueType() && +           "Invalid BITREVERSE!"); +    if (OpOpcode == ISD::UNDEF) +      return getUNDEF(VT); +    break; +  case ISD::BITCAST: +    // Basic sanity checking. +    assert(VT.getSizeInBits() == Operand.getValueSizeInBits() && +           "Cannot BITCAST between types of different sizes!"); +    if (VT == Operand.getValueType()) return Operand;  // noop conversion. +    if (OpOpcode == ISD::BITCAST)  // bitconv(bitconv(x)) -> bitconv(x) +      return getNode(ISD::BITCAST, DL, VT, Operand.getOperand(0)); +    if (OpOpcode == ISD::UNDEF) +      return getUNDEF(VT); +    break; +  case ISD::SCALAR_TO_VECTOR: +    assert(VT.isVector() && !Operand.getValueType().isVector() && +           (VT.getVectorElementType() == Operand.getValueType() || +            (VT.getVectorElementType().isInteger() && +             Operand.getValueType().isInteger() && +             VT.getVectorElementType().bitsLE(Operand.getValueType()))) && +           "Illegal SCALAR_TO_VECTOR node!"); +    if (OpOpcode == ISD::UNDEF) +      return getUNDEF(VT); +    // scalar_to_vector(extract_vector_elt V, 0) -> V, top bits are undefined. +    if (OpOpcode == ISD::EXTRACT_VECTOR_ELT && +        isa<ConstantSDNode>(Operand.getOperand(1)) && +        Operand.getConstantOperandVal(1) == 0 && +        Operand.getOperand(0).getValueType() == VT) +      return Operand.getOperand(0); +    break; +  case ISD::FNEG: +    // -(X-Y) -> (Y-X) is unsafe because when X==Y, -0.0 != +0.0 +    if (getTarget().Options.UnsafeFPMath && OpOpcode == ISD::FSUB) +      // FIXME: FNEG has no fast-math-flags to propagate; use the FSUB's flags? +      return getNode(ISD::FSUB, DL, VT, Operand.getOperand(1), +                     Operand.getOperand(0), Operand.getNode()->getFlags()); +    if (OpOpcode == ISD::FNEG)  // --X -> X +      return Operand.getOperand(0); +    break; +  case ISD::FABS: +    if (OpOpcode == ISD::FNEG)  // abs(-X) -> abs(X) +      return getNode(ISD::FABS, DL, VT, Operand.getOperand(0)); +    break; +  } + +  SDNode *N; +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = {Operand}; +  if (VT != MVT::Glue) { // Don't CSE flag producing nodes +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opcode, VTs, Ops); +    void *IP = nullptr; +    if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) { +      E->intersectFlagsWith(Flags); +      return SDValue(E, 0); +    } + +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    N->setFlags(Flags); +    createOperands(N, Ops); +    CSEMap.InsertNode(N, IP); +  } else { +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    createOperands(N, Ops); +  } + +  InsertNode(N); +  return SDValue(N, 0); +} + +static std::pair<APInt, bool> FoldValue(unsigned Opcode, const APInt &C1, +                                        const APInt &C2) { +  switch (Opcode) { +  case ISD::ADD:  return std::make_pair(C1 + C2, true); +  case ISD::SUB:  return std::make_pair(C1 - C2, true); +  case ISD::MUL:  return std::make_pair(C1 * C2, true); +  case ISD::AND:  return std::make_pair(C1 & C2, true); +  case ISD::OR:   return std::make_pair(C1 | C2, true); +  case ISD::XOR:  return std::make_pair(C1 ^ C2, true); +  case ISD::SHL:  return std::make_pair(C1 << C2, true); +  case ISD::SRL:  return std::make_pair(C1.lshr(C2), true); +  case ISD::SRA:  return std::make_pair(C1.ashr(C2), true); +  case ISD::ROTL: return std::make_pair(C1.rotl(C2), true); +  case ISD::ROTR: return std::make_pair(C1.rotr(C2), true); +  case ISD::SMIN: return std::make_pair(C1.sle(C2) ? C1 : C2, true); +  case ISD::SMAX: return std::make_pair(C1.sge(C2) ? C1 : C2, true); +  case ISD::UMIN: return std::make_pair(C1.ule(C2) ? C1 : C2, true); +  case ISD::UMAX: return std::make_pair(C1.uge(C2) ? C1 : C2, true); +  case ISD::UDIV: +    if (!C2.getBoolValue()) +      break; +    return std::make_pair(C1.udiv(C2), true); +  case ISD::UREM: +    if (!C2.getBoolValue()) +      break; +    return std::make_pair(C1.urem(C2), true); +  case ISD::SDIV: +    if (!C2.getBoolValue()) +      break; +    return std::make_pair(C1.sdiv(C2), true); +  case ISD::SREM: +    if (!C2.getBoolValue()) +      break; +    return std::make_pair(C1.srem(C2), true); +  } +  return std::make_pair(APInt(1, 0), false); +} + +SDValue SelectionDAG::FoldConstantArithmetic(unsigned Opcode, const SDLoc &DL, +                                             EVT VT, const ConstantSDNode *Cst1, +                                             const ConstantSDNode *Cst2) { +  if (Cst1->isOpaque() || Cst2->isOpaque()) +    return SDValue(); + +  std::pair<APInt, bool> Folded = FoldValue(Opcode, Cst1->getAPIntValue(), +                                            Cst2->getAPIntValue()); +  if (!Folded.second) +    return SDValue(); +  return getConstant(Folded.first, DL, VT); +} + +SDValue SelectionDAG::FoldSymbolOffset(unsigned Opcode, EVT VT, +                                       const GlobalAddressSDNode *GA, +                                       const SDNode *N2) { +  if (GA->getOpcode() != ISD::GlobalAddress) +    return SDValue(); +  if (!TLI->isOffsetFoldingLegal(GA)) +    return SDValue(); +  const ConstantSDNode *Cst2 = dyn_cast<ConstantSDNode>(N2); +  if (!Cst2) +    return SDValue(); +  int64_t Offset = Cst2->getSExtValue(); +  switch (Opcode) { +  case ISD::ADD: break; +  case ISD::SUB: Offset = -uint64_t(Offset); break; +  default: return SDValue(); +  } +  return getGlobalAddress(GA->getGlobal(), SDLoc(Cst2), VT, +                          GA->getOffset() + uint64_t(Offset)); +} + +bool SelectionDAG::isUndef(unsigned Opcode, ArrayRef<SDValue> Ops) { +  switch (Opcode) { +  case ISD::SDIV: +  case ISD::UDIV: +  case ISD::SREM: +  case ISD::UREM: { +    // If a divisor is zero/undef or any element of a divisor vector is +    // zero/undef, the whole op is undef. +    assert(Ops.size() == 2 && "Div/rem should have 2 operands"); +    SDValue Divisor = Ops[1]; +    if (Divisor.isUndef() || isNullConstant(Divisor)) +      return true; + +    return ISD::isBuildVectorOfConstantSDNodes(Divisor.getNode()) && +           llvm::any_of(Divisor->op_values(), +                        [](SDValue V) { return V.isUndef() || +                                        isNullConstant(V); }); +    // TODO: Handle signed overflow. +  } +  // TODO: Handle oversized shifts. +  default: +    return false; +  } +} + +SDValue SelectionDAG::FoldConstantArithmetic(unsigned Opcode, const SDLoc &DL, +                                             EVT VT, SDNode *Cst1, +                                             SDNode *Cst2) { +  // If the opcode is a target-specific ISD node, there's nothing we can +  // do here and the operand rules may not line up with the below, so +  // bail early. +  if (Opcode >= ISD::BUILTIN_OP_END) +    return SDValue(); + +  if (isUndef(Opcode, {SDValue(Cst1, 0), SDValue(Cst2, 0)})) +    return getUNDEF(VT); + +  // Handle the case of two scalars. +  if (const ConstantSDNode *Scalar1 = dyn_cast<ConstantSDNode>(Cst1)) { +    if (const ConstantSDNode *Scalar2 = dyn_cast<ConstantSDNode>(Cst2)) { +      SDValue Folded = FoldConstantArithmetic(Opcode, DL, VT, Scalar1, Scalar2); +      assert((!Folded || !VT.isVector()) && +             "Can't fold vectors ops with scalar operands"); +      return Folded; +    } +  } + +  // fold (add Sym, c) -> Sym+c +  if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Cst1)) +    return FoldSymbolOffset(Opcode, VT, GA, Cst2); +  if (TLI->isCommutativeBinOp(Opcode)) +    if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Cst2)) +      return FoldSymbolOffset(Opcode, VT, GA, Cst1); + +  // For vectors extract each constant element into Inputs so we can constant +  // fold them individually. +  BuildVectorSDNode *BV1 = dyn_cast<BuildVectorSDNode>(Cst1); +  BuildVectorSDNode *BV2 = dyn_cast<BuildVectorSDNode>(Cst2); +  if (!BV1 || !BV2) +    return SDValue(); + +  assert(BV1->getNumOperands() == BV2->getNumOperands() && "Out of sync!"); + +  EVT SVT = VT.getScalarType(); +  SmallVector<SDValue, 4> Outputs; +  for (unsigned I = 0, E = BV1->getNumOperands(); I != E; ++I) { +    SDValue V1 = BV1->getOperand(I); +    SDValue V2 = BV2->getOperand(I); + +    // Avoid BUILD_VECTOR nodes that perform implicit truncation. +    // FIXME: This is valid and could be handled by truncation. +    if (V1->getValueType(0) != SVT || V2->getValueType(0) != SVT) +      return SDValue(); + +    // Fold one vector element. +    SDValue ScalarResult = getNode(Opcode, DL, SVT, V1, V2); + +    // Scalar folding only succeeded if the result is a constant or UNDEF. +    if (!ScalarResult.isUndef() && ScalarResult.getOpcode() != ISD::Constant && +        ScalarResult.getOpcode() != ISD::ConstantFP) +      return SDValue(); +    Outputs.push_back(ScalarResult); +  } + +  assert(VT.getVectorNumElements() == Outputs.size() && +         "Vector size mismatch!"); + +  // We may have a vector type but a scalar result. Create a splat. +  Outputs.resize(VT.getVectorNumElements(), Outputs.back()); + +  // Build a big vector out of the scalar elements we generated. +  return getBuildVector(VT, SDLoc(), Outputs); +} + +SDValue SelectionDAG::FoldConstantVectorArithmetic(unsigned Opcode, +                                                   const SDLoc &DL, EVT VT, +                                                   ArrayRef<SDValue> Ops, +                                                   const SDNodeFlags Flags) { +  // If the opcode is a target-specific ISD node, there's nothing we can +  // do here and the operand rules may not line up with the below, so +  // bail early. +  if (Opcode >= ISD::BUILTIN_OP_END) +    return SDValue(); + +  if (isUndef(Opcode, Ops)) +    return getUNDEF(VT); + +  // We can only fold vectors - maybe merge with FoldConstantArithmetic someday? +  if (!VT.isVector()) +    return SDValue(); + +  unsigned NumElts = VT.getVectorNumElements(); + +  auto IsScalarOrSameVectorSize = [&](const SDValue &Op) { +    return !Op.getValueType().isVector() || +           Op.getValueType().getVectorNumElements() == NumElts; +  }; + +  auto IsConstantBuildVectorOrUndef = [&](const SDValue &Op) { +    BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(Op); +    return (Op.isUndef()) || (Op.getOpcode() == ISD::CONDCODE) || +           (BV && BV->isConstant()); +  }; + +  // All operands must be vector types with the same number of elements as +  // the result type and must be either UNDEF or a build vector of constant +  // or UNDEF scalars. +  if (!llvm::all_of(Ops, IsConstantBuildVectorOrUndef) || +      !llvm::all_of(Ops, IsScalarOrSameVectorSize)) +    return SDValue(); + +  // If we are comparing vectors, then the result needs to be a i1 boolean +  // that is then sign-extended back to the legal result type. +  EVT SVT = (Opcode == ISD::SETCC ? MVT::i1 : VT.getScalarType()); + +  // Find legal integer scalar type for constant promotion and +  // ensure that its scalar size is at least as large as source. +  EVT LegalSVT = VT.getScalarType(); +  if (NewNodesMustHaveLegalTypes && LegalSVT.isInteger()) { +    LegalSVT = TLI->getTypeToTransformTo(*getContext(), LegalSVT); +    if (LegalSVT.bitsLT(VT.getScalarType())) +      return SDValue(); +  } + +  // Constant fold each scalar lane separately. +  SmallVector<SDValue, 4> ScalarResults; +  for (unsigned i = 0; i != NumElts; i++) { +    SmallVector<SDValue, 4> ScalarOps; +    for (SDValue Op : Ops) { +      EVT InSVT = Op.getValueType().getScalarType(); +      BuildVectorSDNode *InBV = dyn_cast<BuildVectorSDNode>(Op); +      if (!InBV) { +        // We've checked that this is UNDEF or a constant of some kind. +        if (Op.isUndef()) +          ScalarOps.push_back(getUNDEF(InSVT)); +        else +          ScalarOps.push_back(Op); +        continue; +      } + +      SDValue ScalarOp = InBV->getOperand(i); +      EVT ScalarVT = ScalarOp.getValueType(); + +      // Build vector (integer) scalar operands may need implicit +      // truncation - do this before constant folding. +      if (ScalarVT.isInteger() && ScalarVT.bitsGT(InSVT)) +        ScalarOp = getNode(ISD::TRUNCATE, DL, InSVT, ScalarOp); + +      ScalarOps.push_back(ScalarOp); +    } + +    // Constant fold the scalar operands. +    SDValue ScalarResult = getNode(Opcode, DL, SVT, ScalarOps, Flags); + +    // Legalize the (integer) scalar constant if necessary. +    if (LegalSVT != SVT) +      ScalarResult = getNode(ISD::SIGN_EXTEND, DL, LegalSVT, ScalarResult); + +    // Scalar folding only succeeded if the result is a constant or UNDEF. +    if (!ScalarResult.isUndef() && ScalarResult.getOpcode() != ISD::Constant && +        ScalarResult.getOpcode() != ISD::ConstantFP) +      return SDValue(); +    ScalarResults.push_back(ScalarResult); +  } + +  return getBuildVector(VT, DL, ScalarResults); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, +                              SDValue N1, SDValue N2, const SDNodeFlags Flags) { +  ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1); +  ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2); +  ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1); +  ConstantFPSDNode *N2CFP = dyn_cast<ConstantFPSDNode>(N2); + +  // Canonicalize constant to RHS if commutative. +  if (TLI->isCommutativeBinOp(Opcode)) { +    if (N1C && !N2C) { +      std::swap(N1C, N2C); +      std::swap(N1, N2); +    } else if (N1CFP && !N2CFP) { +      std::swap(N1CFP, N2CFP); +      std::swap(N1, N2); +    } +  } + +  switch (Opcode) { +  default: break; +  case ISD::TokenFactor: +    assert(VT == MVT::Other && N1.getValueType() == MVT::Other && +           N2.getValueType() == MVT::Other && "Invalid token factor!"); +    // Fold trivial token factors. +    if (N1.getOpcode() == ISD::EntryToken) return N2; +    if (N2.getOpcode() == ISD::EntryToken) return N1; +    if (N1 == N2) return N1; +    break; +  case ISD::CONCAT_VECTORS: { +    // Attempt to fold CONCAT_VECTORS into BUILD_VECTOR or UNDEF. +    SDValue Ops[] = {N1, N2}; +    if (SDValue V = FoldCONCAT_VECTORS(DL, VT, Ops, *this)) +      return V; +    break; +  } +  case ISD::AND: +    assert(VT.isInteger() && "This operator does not apply to FP types!"); +    assert(N1.getValueType() == N2.getValueType() && +           N1.getValueType() == VT && "Binary operator types must match!"); +    // (X & 0) -> 0.  This commonly occurs when legalizing i64 values, so it's +    // worth handling here. +    if (N2C && N2C->isNullValue()) +      return N2; +    if (N2C && N2C->isAllOnesValue())  // X & -1 -> X +      return N1; +    break; +  case ISD::OR: +  case ISD::XOR: +  case ISD::ADD: +  case ISD::SUB: +    assert(VT.isInteger() && "This operator does not apply to FP types!"); +    assert(N1.getValueType() == N2.getValueType() && +           N1.getValueType() == VT && "Binary operator types must match!"); +    // (X ^|+- 0) -> X.  This commonly occurs when legalizing i64 values, so +    // it's worth handling here. +    if (N2C && N2C->isNullValue()) +      return N1; +    break; +  case ISD::UDIV: +  case ISD::UREM: +  case ISD::MULHU: +  case ISD::MULHS: +  case ISD::MUL: +  case ISD::SDIV: +  case ISD::SREM: +  case ISD::SMIN: +  case ISD::SMAX: +  case ISD::UMIN: +  case ISD::UMAX: +    assert(VT.isInteger() && "This operator does not apply to FP types!"); +    assert(N1.getValueType() == N2.getValueType() && +           N1.getValueType() == VT && "Binary operator types must match!"); +    break; +  case ISD::FADD: +  case ISD::FSUB: +  case ISD::FMUL: +  case ISD::FDIV: +  case ISD::FREM: +    if (getTarget().Options.UnsafeFPMath) { +      if (Opcode == ISD::FADD) { +        // x+0 --> x +        if (N2CFP && N2CFP->getValueAPF().isZero()) +          return N1; +      } else if (Opcode == ISD::FSUB) { +        // x-0 --> x +        if (N2CFP && N2CFP->getValueAPF().isZero()) +          return N1; +      } else if (Opcode == ISD::FMUL) { +        // x*0 --> 0 +        if (N2CFP && N2CFP->isZero()) +          return N2; +        // x*1 --> x +        if (N2CFP && N2CFP->isExactlyValue(1.0)) +          return N1; +      } +    } +    assert(VT.isFloatingPoint() && "This operator only applies to FP types!"); +    assert(N1.getValueType() == N2.getValueType() && +           N1.getValueType() == VT && "Binary operator types must match!"); +    break; +  case ISD::FCOPYSIGN:   // N1 and result must match.  N1/N2 need not match. +    assert(N1.getValueType() == VT && +           N1.getValueType().isFloatingPoint() && +           N2.getValueType().isFloatingPoint() && +           "Invalid FCOPYSIGN!"); +    break; +  case ISD::SHL: +  case ISD::SRA: +  case ISD::SRL: +  case ISD::ROTL: +  case ISD::ROTR: +    assert(VT == N1.getValueType() && +           "Shift operators return type must be the same as their first arg"); +    assert(VT.isInteger() && N2.getValueType().isInteger() && +           "Shifts only work on integers"); +    assert((!VT.isVector() || VT == N2.getValueType()) && +           "Vector shift amounts must be in the same as their first arg"); +    // Verify that the shift amount VT is bit enough to hold valid shift +    // amounts.  This catches things like trying to shift an i1024 value by an +    // i8, which is easy to fall into in generic code that uses +    // TLI.getShiftAmount(). +    assert(N2.getValueSizeInBits() >= Log2_32_Ceil(N1.getValueSizeInBits()) && +           "Invalid use of small shift amount with oversized value!"); + +    // Always fold shifts of i1 values so the code generator doesn't need to +    // handle them.  Since we know the size of the shift has to be less than the +    // size of the value, the shift/rotate count is guaranteed to be zero. +    if (VT == MVT::i1) +      return N1; +    if (N2C && N2C->isNullValue()) +      return N1; +    break; +  case ISD::FP_ROUND_INREG: { +    EVT EVT = cast<VTSDNode>(N2)->getVT(); +    assert(VT == N1.getValueType() && "Not an inreg round!"); +    assert(VT.isFloatingPoint() && EVT.isFloatingPoint() && +           "Cannot FP_ROUND_INREG integer types"); +    assert(EVT.isVector() == VT.isVector() && +           "FP_ROUND_INREG type should be vector iff the operand " +           "type is vector!"); +    assert((!EVT.isVector() || +            EVT.getVectorNumElements() == VT.getVectorNumElements()) && +           "Vector element counts must match in FP_ROUND_INREG"); +    assert(EVT.bitsLE(VT) && "Not rounding down!"); +    (void)EVT; +    if (cast<VTSDNode>(N2)->getVT() == VT) return N1;  // Not actually rounding. +    break; +  } +  case ISD::FP_ROUND: +    assert(VT.isFloatingPoint() && +           N1.getValueType().isFloatingPoint() && +           VT.bitsLE(N1.getValueType()) && +           N2C && (N2C->getZExtValue() == 0 || N2C->getZExtValue() == 1) && +           "Invalid FP_ROUND!"); +    if (N1.getValueType() == VT) return N1;  // noop conversion. +    break; +  case ISD::AssertSext: +  case ISD::AssertZext: { +    EVT EVT = cast<VTSDNode>(N2)->getVT(); +    assert(VT == N1.getValueType() && "Not an inreg extend!"); +    assert(VT.isInteger() && EVT.isInteger() && +           "Cannot *_EXTEND_INREG FP types"); +    assert(!EVT.isVector() && +           "AssertSExt/AssertZExt type should be the vector element type " +           "rather than the vector type!"); +    assert(EVT.bitsLE(VT) && "Not extending!"); +    if (VT == EVT) return N1; // noop assertion. +    break; +  } +  case ISD::SIGN_EXTEND_INREG: { +    EVT EVT = cast<VTSDNode>(N2)->getVT(); +    assert(VT == N1.getValueType() && "Not an inreg extend!"); +    assert(VT.isInteger() && EVT.isInteger() && +           "Cannot *_EXTEND_INREG FP types"); +    assert(EVT.isVector() == VT.isVector() && +           "SIGN_EXTEND_INREG type should be vector iff the operand " +           "type is vector!"); +    assert((!EVT.isVector() || +            EVT.getVectorNumElements() == VT.getVectorNumElements()) && +           "Vector element counts must match in SIGN_EXTEND_INREG"); +    assert(EVT.bitsLE(VT) && "Not extending!"); +    if (EVT == VT) return N1;  // Not actually extending + +    auto SignExtendInReg = [&](APInt Val, llvm::EVT ConstantVT) { +      unsigned FromBits = EVT.getScalarSizeInBits(); +      Val <<= Val.getBitWidth() - FromBits; +      Val.ashrInPlace(Val.getBitWidth() - FromBits); +      return getConstant(Val, DL, ConstantVT); +    }; + +    if (N1C) { +      const APInt &Val = N1C->getAPIntValue(); +      return SignExtendInReg(Val, VT); +    } +    if (ISD::isBuildVectorOfConstantSDNodes(N1.getNode())) { +      SmallVector<SDValue, 8> Ops; +      llvm::EVT OpVT = N1.getOperand(0).getValueType(); +      for (int i = 0, e = VT.getVectorNumElements(); i != e; ++i) { +        SDValue Op = N1.getOperand(i); +        if (Op.isUndef()) { +          Ops.push_back(getUNDEF(OpVT)); +          continue; +        } +        ConstantSDNode *C = cast<ConstantSDNode>(Op); +        APInt Val = C->getAPIntValue(); +        Ops.push_back(SignExtendInReg(Val, OpVT)); +      } +      return getBuildVector(VT, DL, Ops); +    } +    break; +  } +  case ISD::EXTRACT_VECTOR_ELT: +    // EXTRACT_VECTOR_ELT of an UNDEF is an UNDEF. +    if (N1.isUndef()) +      return getUNDEF(VT); + +    // EXTRACT_VECTOR_ELT of out-of-bounds element is an UNDEF +    if (N2C && N2C->getZExtValue() >= N1.getValueType().getVectorNumElements()) +      return getUNDEF(VT); + +    // EXTRACT_VECTOR_ELT of CONCAT_VECTORS is often formed while lowering is +    // expanding copies of large vectors from registers. +    if (N2C && +        N1.getOpcode() == ISD::CONCAT_VECTORS && +        N1.getNumOperands() > 0) { +      unsigned Factor = +        N1.getOperand(0).getValueType().getVectorNumElements(); +      return getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, +                     N1.getOperand(N2C->getZExtValue() / Factor), +                     getConstant(N2C->getZExtValue() % Factor, DL, +                                 N2.getValueType())); +    } + +    // EXTRACT_VECTOR_ELT of BUILD_VECTOR is often formed while lowering is +    // expanding large vector constants. +    if (N2C && N1.getOpcode() == ISD::BUILD_VECTOR) { +      SDValue Elt = N1.getOperand(N2C->getZExtValue()); + +      if (VT != Elt.getValueType()) +        // If the vector element type is not legal, the BUILD_VECTOR operands +        // are promoted and implicitly truncated, and the result implicitly +        // extended. Make that explicit here. +        Elt = getAnyExtOrTrunc(Elt, DL, VT); + +      return Elt; +    } + +    // EXTRACT_VECTOR_ELT of INSERT_VECTOR_ELT is often formed when vector +    // operations are lowered to scalars. +    if (N1.getOpcode() == ISD::INSERT_VECTOR_ELT) { +      // If the indices are the same, return the inserted element else +      // if the indices are known different, extract the element from +      // the original vector. +      SDValue N1Op2 = N1.getOperand(2); +      ConstantSDNode *N1Op2C = dyn_cast<ConstantSDNode>(N1Op2); + +      if (N1Op2C && N2C) { +        if (N1Op2C->getZExtValue() == N2C->getZExtValue()) { +          if (VT == N1.getOperand(1).getValueType()) +            return N1.getOperand(1); +          else +            return getSExtOrTrunc(N1.getOperand(1), DL, VT); +        } + +        return getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, N1.getOperand(0), N2); +      } +    } +    break; +  case ISD::EXTRACT_ELEMENT: +    assert(N2C && (unsigned)N2C->getZExtValue() < 2 && "Bad EXTRACT_ELEMENT!"); +    assert(!N1.getValueType().isVector() && !VT.isVector() && +           (N1.getValueType().isInteger() == VT.isInteger()) && +           N1.getValueType() != VT && +           "Wrong types for EXTRACT_ELEMENT!"); + +    // EXTRACT_ELEMENT of BUILD_PAIR is often formed while legalize is expanding +    // 64-bit integers into 32-bit parts.  Instead of building the extract of +    // the BUILD_PAIR, only to have legalize rip it apart, just do it now. +    if (N1.getOpcode() == ISD::BUILD_PAIR) +      return N1.getOperand(N2C->getZExtValue()); + +    // EXTRACT_ELEMENT of a constant int is also very common. +    if (N1C) { +      unsigned ElementSize = VT.getSizeInBits(); +      unsigned Shift = ElementSize * N2C->getZExtValue(); +      APInt ShiftedVal = N1C->getAPIntValue().lshr(Shift); +      return getConstant(ShiftedVal.trunc(ElementSize), DL, VT); +    } +    break; +  case ISD::EXTRACT_SUBVECTOR: +    if (VT.isSimple() && N1.getValueType().isSimple()) { +      assert(VT.isVector() && N1.getValueType().isVector() && +             "Extract subvector VTs must be a vectors!"); +      assert(VT.getVectorElementType() == +             N1.getValueType().getVectorElementType() && +             "Extract subvector VTs must have the same element type!"); +      assert(VT.getSimpleVT() <= N1.getSimpleValueType() && +             "Extract subvector must be from larger vector to smaller vector!"); + +      if (N2C) { +        assert((VT.getVectorNumElements() + N2C->getZExtValue() +                <= N1.getValueType().getVectorNumElements()) +               && "Extract subvector overflow!"); +      } + +      // Trivial extraction. +      if (VT.getSimpleVT() == N1.getSimpleValueType()) +        return N1; + +      // EXTRACT_SUBVECTOR of an UNDEF is an UNDEF. +      if (N1.isUndef()) +        return getUNDEF(VT); + +      // EXTRACT_SUBVECTOR of CONCAT_VECTOR can be simplified if the pieces of +      // the concat have the same type as the extract. +      if (N2C && N1.getOpcode() == ISD::CONCAT_VECTORS && +          N1.getNumOperands() > 0 && +          VT == N1.getOperand(0).getValueType()) { +        unsigned Factor = VT.getVectorNumElements(); +        return N1.getOperand(N2C->getZExtValue() / Factor); +      } + +      // EXTRACT_SUBVECTOR of INSERT_SUBVECTOR is often created +      // during shuffle legalization. +      if (N1.getOpcode() == ISD::INSERT_SUBVECTOR && N2 == N1.getOperand(2) && +          VT == N1.getOperand(1).getValueType()) +        return N1.getOperand(1); +    } +    break; +  } + +  // Perform trivial constant folding. +  if (SDValue SV = +          FoldConstantArithmetic(Opcode, DL, VT, N1.getNode(), N2.getNode())) +    return SV; + +  // Constant fold FP operations. +  bool HasFPExceptions = TLI->hasFloatingPointExceptions(); +  if (N1CFP) { +    if (N2CFP) { +      APFloat V1 = N1CFP->getValueAPF(), V2 = N2CFP->getValueAPF(); +      APFloat::opStatus s; +      switch (Opcode) { +      case ISD::FADD: +        s = V1.add(V2, APFloat::rmNearestTiesToEven); +        if (!HasFPExceptions || s != APFloat::opInvalidOp) +          return getConstantFP(V1, DL, VT); +        break; +      case ISD::FSUB: +        s = V1.subtract(V2, APFloat::rmNearestTiesToEven); +        if (!HasFPExceptions || s!=APFloat::opInvalidOp) +          return getConstantFP(V1, DL, VT); +        break; +      case ISD::FMUL: +        s = V1.multiply(V2, APFloat::rmNearestTiesToEven); +        if (!HasFPExceptions || s!=APFloat::opInvalidOp) +          return getConstantFP(V1, DL, VT); +        break; +      case ISD::FDIV: +        s = V1.divide(V2, APFloat::rmNearestTiesToEven); +        if (!HasFPExceptions || (s!=APFloat::opInvalidOp && +                                 s!=APFloat::opDivByZero)) { +          return getConstantFP(V1, DL, VT); +        } +        break; +      case ISD::FREM : +        s = V1.mod(V2); +        if (!HasFPExceptions || (s!=APFloat::opInvalidOp && +                                 s!=APFloat::opDivByZero)) { +          return getConstantFP(V1, DL, VT); +        } +        break; +      case ISD::FCOPYSIGN: +        V1.copySign(V2); +        return getConstantFP(V1, DL, VT); +      default: break; +      } +    } + +    if (Opcode == ISD::FP_ROUND) { +      APFloat V = N1CFP->getValueAPF();    // make copy +      bool ignored; +      // This can return overflow, underflow, or inexact; we don't care. +      // FIXME need to be more flexible about rounding mode. +      (void)V.convert(EVTToAPFloatSemantics(VT), +                      APFloat::rmNearestTiesToEven, &ignored); +      return getConstantFP(V, DL, VT); +    } +  } + +  // Canonicalize an UNDEF to the RHS, even over a constant. +  if (N1.isUndef()) { +    if (TLI->isCommutativeBinOp(Opcode)) { +      std::swap(N1, N2); +    } else { +      switch (Opcode) { +      case ISD::FP_ROUND_INREG: +      case ISD::SIGN_EXTEND_INREG: +      case ISD::SUB: +      case ISD::FSUB: +      case ISD::FDIV: +      case ISD::FREM: +      case ISD::SRA: +        return N1;     // fold op(undef, arg2) -> undef +      case ISD::UDIV: +      case ISD::SDIV: +      case ISD::UREM: +      case ISD::SREM: +      case ISD::SRL: +      case ISD::SHL: +        if (!VT.isVector()) +          return getConstant(0, DL, VT);    // fold op(undef, arg2) -> 0 +        // For vectors, we can't easily build an all zero vector, just return +        // the LHS. +        return N2; +      } +    } +  } + +  // Fold a bunch of operators when the RHS is undef. +  if (N2.isUndef()) { +    switch (Opcode) { +    case ISD::XOR: +      if (N1.isUndef()) +        // Handle undef ^ undef -> 0 special case. This is a common +        // idiom (misuse). +        return getConstant(0, DL, VT); +      LLVM_FALLTHROUGH; +    case ISD::ADD: +    case ISD::ADDC: +    case ISD::ADDE: +    case ISD::SUB: +    case ISD::UDIV: +    case ISD::SDIV: +    case ISD::UREM: +    case ISD::SREM: +      return N2;       // fold op(arg1, undef) -> undef +    case ISD::FADD: +    case ISD::FSUB: +    case ISD::FMUL: +    case ISD::FDIV: +    case ISD::FREM: +      if (getTarget().Options.UnsafeFPMath) +        return N2; +      break; +    case ISD::MUL: +    case ISD::AND: +    case ISD::SRL: +    case ISD::SHL: +      if (!VT.isVector()) +        return getConstant(0, DL, VT);  // fold op(arg1, undef) -> 0 +      // For vectors, we can't easily build an all zero vector, just return +      // the LHS. +      return N1; +    case ISD::OR: +      if (!VT.isVector()) +        return getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), DL, VT); +      // For vectors, we can't easily build an all one vector, just return +      // the LHS. +      return N1; +    case ISD::SRA: +      return N1; +    } +  } + +  // Memoize this node if possible. +  SDNode *N; +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = {N1, N2}; +  if (VT != MVT::Glue) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opcode, VTs, Ops); +    void *IP = nullptr; +    if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) { +      E->intersectFlagsWith(Flags); +      return SDValue(E, 0); +    } + +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    N->setFlags(Flags); +    createOperands(N, Ops); +    CSEMap.InsertNode(N, IP); +  } else { +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    createOperands(N, Ops); +  } + +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, +                              SDValue N1, SDValue N2, SDValue N3) { +  // Perform various simplifications. +  switch (Opcode) { +  case ISD::FMA: { +    ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1); +    ConstantFPSDNode *N2CFP = dyn_cast<ConstantFPSDNode>(N2); +    ConstantFPSDNode *N3CFP = dyn_cast<ConstantFPSDNode>(N3); +    if (N1CFP && N2CFP && N3CFP) { +      APFloat  V1 = N1CFP->getValueAPF(); +      const APFloat &V2 = N2CFP->getValueAPF(); +      const APFloat &V3 = N3CFP->getValueAPF(); +      APFloat::opStatus s = +        V1.fusedMultiplyAdd(V2, V3, APFloat::rmNearestTiesToEven); +      if (!TLI->hasFloatingPointExceptions() || s != APFloat::opInvalidOp) +        return getConstantFP(V1, DL, VT); +    } +    break; +  } +  case ISD::CONCAT_VECTORS: { +    // Attempt to fold CONCAT_VECTORS into BUILD_VECTOR or UNDEF. +    SDValue Ops[] = {N1, N2, N3}; +    if (SDValue V = FoldCONCAT_VECTORS(DL, VT, Ops, *this)) +      return V; +    break; +  } +  case ISD::SETCC: { +    // Use FoldSetCC to simplify SETCC's. +    if (SDValue V = FoldSetCC(VT, N1, N2, cast<CondCodeSDNode>(N3)->get(), DL)) +      return V; +    // Vector constant folding. +    SDValue Ops[] = {N1, N2, N3}; +    if (SDValue V = FoldConstantVectorArithmetic(Opcode, DL, VT, Ops)) +      return V; +    break; +  } +  case ISD::SELECT: +    if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1)) { +     if (N1C->getZExtValue()) +       return N2;             // select true, X, Y -> X +     return N3;             // select false, X, Y -> Y +    } + +    if (N2 == N3) return N2;   // select C, X, X -> X +    break; +  case ISD::VECTOR_SHUFFLE: +    llvm_unreachable("should use getVectorShuffle constructor!"); +  case ISD::INSERT_VECTOR_ELT: { +    ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3); +    // INSERT_VECTOR_ELT into out-of-bounds element is an UNDEF +    if (N3C && N3C->getZExtValue() >= N1.getValueType().getVectorNumElements()) +      return getUNDEF(VT); +    break; +  } +  case ISD::INSERT_SUBVECTOR: { +    SDValue Index = N3; +    if (VT.isSimple() && N1.getValueType().isSimple() +        && N2.getValueType().isSimple()) { +      assert(VT.isVector() && N1.getValueType().isVector() && +             N2.getValueType().isVector() && +             "Insert subvector VTs must be a vectors"); +      assert(VT == N1.getValueType() && +             "Dest and insert subvector source types must match!"); +      assert(N2.getSimpleValueType() <= N1.getSimpleValueType() && +             "Insert subvector must be from smaller vector to larger vector!"); +      if (isa<ConstantSDNode>(Index)) { +        assert((N2.getValueType().getVectorNumElements() + +                cast<ConstantSDNode>(Index)->getZExtValue() +                <= VT.getVectorNumElements()) +               && "Insert subvector overflow!"); +      } + +      // Trivial insertion. +      if (VT.getSimpleVT() == N2.getSimpleValueType()) +        return N2; +    } +    break; +  } +  case ISD::BITCAST: +    // Fold bit_convert nodes from a type to themselves. +    if (N1.getValueType() == VT) +      return N1; +    break; +  } + +  // Memoize node if it doesn't produce a flag. +  SDNode *N; +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = {N1, N2, N3}; +  if (VT != MVT::Glue) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opcode, VTs, Ops); +    void *IP = nullptr; +    if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) +      return SDValue(E, 0); + +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    createOperands(N, Ops); +    CSEMap.InsertNode(N, IP); +  } else { +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    createOperands(N, Ops); +  } + +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, +                              SDValue N1, SDValue N2, SDValue N3, SDValue N4) { +  SDValue Ops[] = { N1, N2, N3, N4 }; +  return getNode(Opcode, DL, VT, Ops); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, +                              SDValue N1, SDValue N2, SDValue N3, SDValue N4, +                              SDValue N5) { +  SDValue Ops[] = { N1, N2, N3, N4, N5 }; +  return getNode(Opcode, DL, VT, Ops); +} + +/// getStackArgumentTokenFactor - Compute a TokenFactor to force all +/// the incoming stack arguments to be loaded from the stack. +SDValue SelectionDAG::getStackArgumentTokenFactor(SDValue Chain) { +  SmallVector<SDValue, 8> ArgChains; + +  // Include the original chain at the beginning of the list. When this is +  // used by target LowerCall hooks, this helps legalize find the +  // CALLSEQ_BEGIN node. +  ArgChains.push_back(Chain); + +  // Add a chain value for each stack argument. +  for (SDNode::use_iterator U = getEntryNode().getNode()->use_begin(), +       UE = getEntryNode().getNode()->use_end(); U != UE; ++U) +    if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U)) +      if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr())) +        if (FI->getIndex() < 0) +          ArgChains.push_back(SDValue(L, 1)); + +  // Build a tokenfactor for all the chains. +  return getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains); +} + +/// getMemsetValue - Vectorized representation of the memset value +/// operand. +static SDValue getMemsetValue(SDValue Value, EVT VT, SelectionDAG &DAG, +                              const SDLoc &dl) { +  assert(!Value.isUndef()); + +  unsigned NumBits = VT.getScalarSizeInBits(); +  if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Value)) { +    assert(C->getAPIntValue().getBitWidth() == 8); +    APInt Val = APInt::getSplat(NumBits, C->getAPIntValue()); +    if (VT.isInteger()) +      return DAG.getConstant(Val, dl, VT); +    return DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(VT), Val), dl, +                             VT); +  } + +  assert(Value.getValueType() == MVT::i8 && "memset with non-byte fill value?"); +  EVT IntVT = VT.getScalarType(); +  if (!IntVT.isInteger()) +    IntVT = EVT::getIntegerVT(*DAG.getContext(), IntVT.getSizeInBits()); + +  Value = DAG.getNode(ISD::ZERO_EXTEND, dl, IntVT, Value); +  if (NumBits > 8) { +    // Use a multiplication with 0x010101... to extend the input to the +    // required length. +    APInt Magic = APInt::getSplat(NumBits, APInt(8, 0x01)); +    Value = DAG.getNode(ISD::MUL, dl, IntVT, Value, +                        DAG.getConstant(Magic, dl, IntVT)); +  } + +  if (VT != Value.getValueType() && !VT.isInteger()) +    Value = DAG.getBitcast(VT.getScalarType(), Value); +  if (VT != Value.getValueType()) +    Value = DAG.getSplatBuildVector(VT, dl, Value); + +  return Value; +} + +/// getMemsetStringVal - Similar to getMemsetValue. Except this is only +/// used when a memcpy is turned into a memset when the source is a constant +/// string ptr. +static SDValue getMemsetStringVal(EVT VT, const SDLoc &dl, SelectionDAG &DAG, +                                  const TargetLowering &TLI, +                                  const ConstantDataArraySlice &Slice) { +  // Handle vector with all elements zero. +  if (Slice.Array == nullptr) { +    if (VT.isInteger()) +      return DAG.getConstant(0, dl, VT); +    else if (VT == MVT::f32 || VT == MVT::f64 || VT == MVT::f128) +      return DAG.getConstantFP(0.0, dl, VT); +    else if (VT.isVector()) { +      unsigned NumElts = VT.getVectorNumElements(); +      MVT EltVT = (VT.getVectorElementType() == MVT::f32) ? MVT::i32 : MVT::i64; +      return DAG.getNode(ISD::BITCAST, dl, VT, +                         DAG.getConstant(0, dl, +                                         EVT::getVectorVT(*DAG.getContext(), +                                                          EltVT, NumElts))); +    } else +      llvm_unreachable("Expected type!"); +  } + +  assert(!VT.isVector() && "Can't handle vector type here!"); +  unsigned NumVTBits = VT.getSizeInBits(); +  unsigned NumVTBytes = NumVTBits / 8; +  unsigned NumBytes = std::min(NumVTBytes, unsigned(Slice.Length)); + +  APInt Val(NumVTBits, 0); +  if (DAG.getDataLayout().isLittleEndian()) { +    for (unsigned i = 0; i != NumBytes; ++i) +      Val |= (uint64_t)(unsigned char)Slice[i] << i*8; +  } else { +    for (unsigned i = 0; i != NumBytes; ++i) +      Val |= (uint64_t)(unsigned char)Slice[i] << (NumVTBytes-i-1)*8; +  } + +  // If the "cost" of materializing the integer immediate is less than the cost +  // of a load, then it is cost effective to turn the load into the immediate. +  Type *Ty = VT.getTypeForEVT(*DAG.getContext()); +  if (TLI.shouldConvertConstantLoadToIntImm(Val, Ty)) +    return DAG.getConstant(Val, dl, VT); +  return SDValue(nullptr, 0); +} + +SDValue SelectionDAG::getMemBasePlusOffset(SDValue Base, unsigned Offset, +                                           const SDLoc &DL) { +  EVT VT = Base.getValueType(); +  return getNode(ISD::ADD, DL, VT, Base, getConstant(Offset, DL, VT)); +} + +/// Returns true if memcpy source is constant data. +static bool isMemSrcFromConstant(SDValue Src, ConstantDataArraySlice &Slice) { +  uint64_t SrcDelta = 0; +  GlobalAddressSDNode *G = nullptr; +  if (Src.getOpcode() == ISD::GlobalAddress) +    G = cast<GlobalAddressSDNode>(Src); +  else if (Src.getOpcode() == ISD::ADD && +           Src.getOperand(0).getOpcode() == ISD::GlobalAddress && +           Src.getOperand(1).getOpcode() == ISD::Constant) { +    G = cast<GlobalAddressSDNode>(Src.getOperand(0)); +    SrcDelta = cast<ConstantSDNode>(Src.getOperand(1))->getZExtValue(); +  } +  if (!G) +    return false; + +  return getConstantDataArrayInfo(G->getGlobal(), Slice, 8, +                                  SrcDelta + G->getOffset()); +} + +/// Determines the optimal series of memory ops to replace the memset / memcpy. +/// Return true if the number of memory ops is below the threshold (Limit). +/// It returns the types of the sequence of memory ops to perform +/// memset / memcpy by reference. +static bool FindOptimalMemOpLowering(std::vector<EVT> &MemOps, +                                     unsigned Limit, uint64_t Size, +                                     unsigned DstAlign, unsigned SrcAlign, +                                     bool IsMemset, +                                     bool ZeroMemset, +                                     bool MemcpyStrSrc, +                                     bool AllowOverlap, +                                     unsigned DstAS, unsigned SrcAS, +                                     SelectionDAG &DAG, +                                     const TargetLowering &TLI) { +  assert((SrcAlign == 0 || SrcAlign >= DstAlign) && +         "Expecting memcpy / memset source to meet alignment requirement!"); +  // If 'SrcAlign' is zero, that means the memory operation does not need to +  // load the value, i.e. memset or memcpy from constant string. Otherwise, +  // it's the inferred alignment of the source. 'DstAlign', on the other hand, +  // is the specified alignment of the memory operation. If it is zero, that +  // means it's possible to change the alignment of the destination. +  // 'MemcpyStrSrc' indicates whether the memcpy source is constant so it does +  // not need to be loaded. +  EVT VT = TLI.getOptimalMemOpType(Size, DstAlign, SrcAlign, +                                   IsMemset, ZeroMemset, MemcpyStrSrc, +                                   DAG.getMachineFunction()); + +  if (VT == MVT::Other) { +    // Use the largest integer type whose alignment constraints are satisfied. +    // We only need to check DstAlign here as SrcAlign is always greater or +    // equal to DstAlign (or zero). +    VT = MVT::i64; +    while (DstAlign && DstAlign < VT.getSizeInBits() / 8 && +           !TLI.allowsMisalignedMemoryAccesses(VT, DstAS, DstAlign)) +      VT = (MVT::SimpleValueType)(VT.getSimpleVT().SimpleTy - 1); +    assert(VT.isInteger()); + +    // Find the largest legal integer type. +    MVT LVT = MVT::i64; +    while (!TLI.isTypeLegal(LVT)) +      LVT = (MVT::SimpleValueType)(LVT.SimpleTy - 1); +    assert(LVT.isInteger()); + +    // If the type we've chosen is larger than the largest legal integer type +    // then use that instead. +    if (VT.bitsGT(LVT)) +      VT = LVT; +  } + +  unsigned NumMemOps = 0; +  while (Size != 0) { +    unsigned VTSize = VT.getSizeInBits() / 8; +    while (VTSize > Size) { +      // For now, only use non-vector load / store's for the left-over pieces. +      EVT NewVT = VT; +      unsigned NewVTSize; + +      bool Found = false; +      if (VT.isVector() || VT.isFloatingPoint()) { +        NewVT = (VT.getSizeInBits() > 64) ? MVT::i64 : MVT::i32; +        if (TLI.isOperationLegalOrCustom(ISD::STORE, NewVT) && +            TLI.isSafeMemOpType(NewVT.getSimpleVT())) +          Found = true; +        else if (NewVT == MVT::i64 && +                 TLI.isOperationLegalOrCustom(ISD::STORE, MVT::f64) && +                 TLI.isSafeMemOpType(MVT::f64)) { +          // i64 is usually not legal on 32-bit targets, but f64 may be. +          NewVT = MVT::f64; +          Found = true; +        } +      } + +      if (!Found) { +        do { +          NewVT = (MVT::SimpleValueType)(NewVT.getSimpleVT().SimpleTy - 1); +          if (NewVT == MVT::i8) +            break; +        } while (!TLI.isSafeMemOpType(NewVT.getSimpleVT())); +      } +      NewVTSize = NewVT.getSizeInBits() / 8; + +      // If the new VT cannot cover all of the remaining bits, then consider +      // issuing a (or a pair of) unaligned and overlapping load / store. +      // FIXME: Only does this for 64-bit or more since we don't have proper +      // cost model for unaligned load / store. +      bool Fast; +      if (NumMemOps && AllowOverlap && +          VTSize >= 8 && NewVTSize < Size && +          TLI.allowsMisalignedMemoryAccesses(VT, DstAS, DstAlign, &Fast) && Fast) +        VTSize = Size; +      else { +        VT = NewVT; +        VTSize = NewVTSize; +      } +    } + +    if (++NumMemOps > Limit) +      return false; + +    MemOps.push_back(VT); +    Size -= VTSize; +  } + +  return true; +} + +static bool shouldLowerMemFuncForSize(const MachineFunction &MF) { +  // On Darwin, -Os means optimize for size without hurting performance, so +  // only really optimize for size when -Oz (MinSize) is used. +  if (MF.getTarget().getTargetTriple().isOSDarwin()) +    return MF.getFunction()->optForMinSize(); +  return MF.getFunction()->optForSize(); +} + +static SDValue getMemcpyLoadsAndStores(SelectionDAG &DAG, const SDLoc &dl, +                                       SDValue Chain, SDValue Dst, SDValue Src, +                                       uint64_t Size, unsigned Align, +                                       bool isVol, bool AlwaysInline, +                                       MachinePointerInfo DstPtrInfo, +                                       MachinePointerInfo SrcPtrInfo) { +  // Turn a memcpy of undef to nop. +  if (Src.isUndef()) +    return Chain; + +  // Expand memcpy to a series of load and store ops if the size operand falls +  // below a certain threshold. +  // TODO: In the AlwaysInline case, if the size is big then generate a loop +  // rather than maybe a humongous number of loads and stores. +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  std::vector<EVT> MemOps; +  bool DstAlignCanChange = false; +  MachineFunction &MF = DAG.getMachineFunction(); +  MachineFrameInfo &MFI = MF.getFrameInfo(); +  bool OptSize = shouldLowerMemFuncForSize(MF); +  FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Dst); +  if (FI && !MFI.isFixedObjectIndex(FI->getIndex())) +    DstAlignCanChange = true; +  unsigned SrcAlign = DAG.InferPtrAlignment(Src); +  if (Align > SrcAlign) +    SrcAlign = Align; +  ConstantDataArraySlice Slice; +  bool CopyFromConstant = isMemSrcFromConstant(Src, Slice); +  bool isZeroConstant = CopyFromConstant && Slice.Array == nullptr; +  unsigned Limit = AlwaysInline ? ~0U : TLI.getMaxStoresPerMemcpy(OptSize); + +  if (!FindOptimalMemOpLowering(MemOps, Limit, Size, +                                (DstAlignCanChange ? 0 : Align), +                                (isZeroConstant ? 0 : SrcAlign), +                                false, false, CopyFromConstant, true, +                                DstPtrInfo.getAddrSpace(), +                                SrcPtrInfo.getAddrSpace(), +                                DAG, TLI)) +    return SDValue(); + +  if (DstAlignCanChange) { +    Type *Ty = MemOps[0].getTypeForEVT(*DAG.getContext()); +    unsigned NewAlign = (unsigned)DAG.getDataLayout().getABITypeAlignment(Ty); + +    // Don't promote to an alignment that would require dynamic stack +    // realignment. +    const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); +    if (!TRI->needsStackRealignment(MF)) +      while (NewAlign > Align && +             DAG.getDataLayout().exceedsNaturalStackAlignment(NewAlign)) +          NewAlign /= 2; + +    if (NewAlign > Align) { +      // Give the stack frame object a larger alignment if needed. +      if (MFI.getObjectAlignment(FI->getIndex()) < NewAlign) +        MFI.setObjectAlignment(FI->getIndex(), NewAlign); +      Align = NewAlign; +    } +  } + +  MachineMemOperand::Flags MMOFlags = +      isVol ? MachineMemOperand::MOVolatile : MachineMemOperand::MONone; +  SmallVector<SDValue, 8> OutChains; +  unsigned NumMemOps = MemOps.size(); +  uint64_t SrcOff = 0, DstOff = 0; +  for (unsigned i = 0; i != NumMemOps; ++i) { +    EVT VT = MemOps[i]; +    unsigned VTSize = VT.getSizeInBits() / 8; +    SDValue Value, Store; + +    if (VTSize > Size) { +      // Issuing an unaligned load / store pair  that overlaps with the previous +      // pair. Adjust the offset accordingly. +      assert(i == NumMemOps-1 && i != 0); +      SrcOff -= VTSize - Size; +      DstOff -= VTSize - Size; +    } + +    if (CopyFromConstant && +        (isZeroConstant || (VT.isInteger() && !VT.isVector()))) { +      // It's unlikely a store of a vector immediate can be done in a single +      // instruction. It would require a load from a constantpool first. +      // We only handle zero vectors here. +      // FIXME: Handle other cases where store of vector immediate is done in +      // a single instruction. +      ConstantDataArraySlice SubSlice; +      if (SrcOff < Slice.Length) { +        SubSlice = Slice; +        SubSlice.move(SrcOff); +      } else { +        // This is an out-of-bounds access and hence UB. Pretend we read zero. +        SubSlice.Array = nullptr; +        SubSlice.Offset = 0; +        SubSlice.Length = VTSize; +      } +      Value = getMemsetStringVal(VT, dl, DAG, TLI, SubSlice); +      if (Value.getNode()) +        Store = DAG.getStore(Chain, dl, Value, +                             DAG.getMemBasePlusOffset(Dst, DstOff, dl), +                             DstPtrInfo.getWithOffset(DstOff), Align, +                             MMOFlags); +    } + +    if (!Store.getNode()) { +      // The type might not be legal for the target.  This should only happen +      // if the type is smaller than a legal type, as on PPC, so the right +      // thing to do is generate a LoadExt/StoreTrunc pair.  These simplify +      // to Load/Store if NVT==VT. +      // FIXME does the case above also need this? +      EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), VT); +      assert(NVT.bitsGE(VT)); +      Value = DAG.getExtLoad(ISD::EXTLOAD, dl, NVT, Chain, +                             DAG.getMemBasePlusOffset(Src, SrcOff, dl), +                             SrcPtrInfo.getWithOffset(SrcOff), VT, +                             MinAlign(SrcAlign, SrcOff), MMOFlags); +      OutChains.push_back(Value.getValue(1)); +      Store = DAG.getTruncStore( +          Chain, dl, Value, DAG.getMemBasePlusOffset(Dst, DstOff, dl), +          DstPtrInfo.getWithOffset(DstOff), VT, Align, MMOFlags); +    } +    OutChains.push_back(Store); +    SrcOff += VTSize; +    DstOff += VTSize; +    Size -= VTSize; +  } + +  return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, OutChains); +} + +static SDValue getMemmoveLoadsAndStores(SelectionDAG &DAG, const SDLoc &dl, +                                        SDValue Chain, SDValue Dst, SDValue Src, +                                        uint64_t Size, unsigned Align, +                                        bool isVol, bool AlwaysInline, +                                        MachinePointerInfo DstPtrInfo, +                                        MachinePointerInfo SrcPtrInfo) { +  // Turn a memmove of undef to nop. +  if (Src.isUndef()) +    return Chain; + +  // Expand memmove to a series of load and store ops if the size operand falls +  // below a certain threshold. +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  std::vector<EVT> MemOps; +  bool DstAlignCanChange = false; +  MachineFunction &MF = DAG.getMachineFunction(); +  MachineFrameInfo &MFI = MF.getFrameInfo(); +  bool OptSize = shouldLowerMemFuncForSize(MF); +  FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Dst); +  if (FI && !MFI.isFixedObjectIndex(FI->getIndex())) +    DstAlignCanChange = true; +  unsigned SrcAlign = DAG.InferPtrAlignment(Src); +  if (Align > SrcAlign) +    SrcAlign = Align; +  unsigned Limit = AlwaysInline ? ~0U : TLI.getMaxStoresPerMemmove(OptSize); + +  if (!FindOptimalMemOpLowering(MemOps, Limit, Size, +                                (DstAlignCanChange ? 0 : Align), SrcAlign, +                                false, false, false, false, +                                DstPtrInfo.getAddrSpace(), +                                SrcPtrInfo.getAddrSpace(), +                                DAG, TLI)) +    return SDValue(); + +  if (DstAlignCanChange) { +    Type *Ty = MemOps[0].getTypeForEVT(*DAG.getContext()); +    unsigned NewAlign = (unsigned)DAG.getDataLayout().getABITypeAlignment(Ty); +    if (NewAlign > Align) { +      // Give the stack frame object a larger alignment if needed. +      if (MFI.getObjectAlignment(FI->getIndex()) < NewAlign) +        MFI.setObjectAlignment(FI->getIndex(), NewAlign); +      Align = NewAlign; +    } +  } + +  MachineMemOperand::Flags MMOFlags = +      isVol ? MachineMemOperand::MOVolatile : MachineMemOperand::MONone; +  uint64_t SrcOff = 0, DstOff = 0; +  SmallVector<SDValue, 8> LoadValues; +  SmallVector<SDValue, 8> LoadChains; +  SmallVector<SDValue, 8> OutChains; +  unsigned NumMemOps = MemOps.size(); +  for (unsigned i = 0; i < NumMemOps; i++) { +    EVT VT = MemOps[i]; +    unsigned VTSize = VT.getSizeInBits() / 8; +    SDValue Value; + +    Value = +        DAG.getLoad(VT, dl, Chain, DAG.getMemBasePlusOffset(Src, SrcOff, dl), +                    SrcPtrInfo.getWithOffset(SrcOff), SrcAlign, MMOFlags); +    LoadValues.push_back(Value); +    LoadChains.push_back(Value.getValue(1)); +    SrcOff += VTSize; +  } +  Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, LoadChains); +  OutChains.clear(); +  for (unsigned i = 0; i < NumMemOps; i++) { +    EVT VT = MemOps[i]; +    unsigned VTSize = VT.getSizeInBits() / 8; +    SDValue Store; + +    Store = DAG.getStore(Chain, dl, LoadValues[i], +                         DAG.getMemBasePlusOffset(Dst, DstOff, dl), +                         DstPtrInfo.getWithOffset(DstOff), Align, MMOFlags); +    OutChains.push_back(Store); +    DstOff += VTSize; +  } + +  return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, OutChains); +} + +/// \brief Lower the call to 'memset' intrinsic function into a series of store +/// operations. +/// +/// \param DAG Selection DAG where lowered code is placed. +/// \param dl Link to corresponding IR location. +/// \param Chain Control flow dependency. +/// \param Dst Pointer to destination memory location. +/// \param Src Value of byte to write into the memory. +/// \param Size Number of bytes to write. +/// \param Align Alignment of the destination in bytes. +/// \param isVol True if destination is volatile. +/// \param DstPtrInfo IR information on the memory pointer. +/// \returns New head in the control flow, if lowering was successful, empty +/// SDValue otherwise. +/// +/// The function tries to replace 'llvm.memset' intrinsic with several store +/// operations and value calculation code. This is usually profitable for small +/// memory size. +static SDValue getMemsetStores(SelectionDAG &DAG, const SDLoc &dl, +                               SDValue Chain, SDValue Dst, SDValue Src, +                               uint64_t Size, unsigned Align, bool isVol, +                               MachinePointerInfo DstPtrInfo) { +  // Turn a memset of undef to nop. +  if (Src.isUndef()) +    return Chain; + +  // Expand memset to a series of load/store ops if the size operand +  // falls below a certain threshold. +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  std::vector<EVT> MemOps; +  bool DstAlignCanChange = false; +  MachineFunction &MF = DAG.getMachineFunction(); +  MachineFrameInfo &MFI = MF.getFrameInfo(); +  bool OptSize = shouldLowerMemFuncForSize(MF); +  FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Dst); +  if (FI && !MFI.isFixedObjectIndex(FI->getIndex())) +    DstAlignCanChange = true; +  bool IsZeroVal = +    isa<ConstantSDNode>(Src) && cast<ConstantSDNode>(Src)->isNullValue(); +  if (!FindOptimalMemOpLowering(MemOps, TLI.getMaxStoresPerMemset(OptSize), +                                Size, (DstAlignCanChange ? 0 : Align), 0, +                                true, IsZeroVal, false, true, +                                DstPtrInfo.getAddrSpace(), ~0u, +                                DAG, TLI)) +    return SDValue(); + +  if (DstAlignCanChange) { +    Type *Ty = MemOps[0].getTypeForEVT(*DAG.getContext()); +    unsigned NewAlign = (unsigned)DAG.getDataLayout().getABITypeAlignment(Ty); +    if (NewAlign > Align) { +      // Give the stack frame object a larger alignment if needed. +      if (MFI.getObjectAlignment(FI->getIndex()) < NewAlign) +        MFI.setObjectAlignment(FI->getIndex(), NewAlign); +      Align = NewAlign; +    } +  } + +  SmallVector<SDValue, 8> OutChains; +  uint64_t DstOff = 0; +  unsigned NumMemOps = MemOps.size(); + +  // Find the largest store and generate the bit pattern for it. +  EVT LargestVT = MemOps[0]; +  for (unsigned i = 1; i < NumMemOps; i++) +    if (MemOps[i].bitsGT(LargestVT)) +      LargestVT = MemOps[i]; +  SDValue MemSetValue = getMemsetValue(Src, LargestVT, DAG, dl); + +  for (unsigned i = 0; i < NumMemOps; i++) { +    EVT VT = MemOps[i]; +    unsigned VTSize = VT.getSizeInBits() / 8; +    if (VTSize > Size) { +      // Issuing an unaligned load / store pair  that overlaps with the previous +      // pair. Adjust the offset accordingly. +      assert(i == NumMemOps-1 && i != 0); +      DstOff -= VTSize - Size; +    } + +    // If this store is smaller than the largest store see whether we can get +    // the smaller value for free with a truncate. +    SDValue Value = MemSetValue; +    if (VT.bitsLT(LargestVT)) { +      if (!LargestVT.isVector() && !VT.isVector() && +          TLI.isTruncateFree(LargestVT, VT)) +        Value = DAG.getNode(ISD::TRUNCATE, dl, VT, MemSetValue); +      else +        Value = getMemsetValue(Src, VT, DAG, dl); +    } +    assert(Value.getValueType() == VT && "Value with wrong type."); +    SDValue Store = DAG.getStore( +        Chain, dl, Value, DAG.getMemBasePlusOffset(Dst, DstOff, dl), +        DstPtrInfo.getWithOffset(DstOff), Align, +        isVol ? MachineMemOperand::MOVolatile : MachineMemOperand::MONone); +    OutChains.push_back(Store); +    DstOff += VT.getSizeInBits() / 8; +    Size -= VTSize; +  } + +  return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, OutChains); +} + +static void checkAddrSpaceIsValidForLibcall(const TargetLowering *TLI, +                                            unsigned AS) { +  // Lowering memcpy / memset / memmove intrinsics to calls is only valid if all +  // pointer operands can be losslessly bitcasted to pointers of address space 0 +  if (AS != 0 && !TLI->isNoopAddrSpaceCast(AS, 0)) { +    report_fatal_error("cannot lower memory intrinsic in address space " + +                       Twine(AS)); +  } +} + +SDValue SelectionDAG::getMemcpy(SDValue Chain, const SDLoc &dl, SDValue Dst, +                                SDValue Src, SDValue Size, unsigned Align, +                                bool isVol, bool AlwaysInline, bool isTailCall, +                                MachinePointerInfo DstPtrInfo, +                                MachinePointerInfo SrcPtrInfo) { +  assert(Align && "The SDAG layer expects explicit alignment and reserves 0"); + +  // Check to see if we should lower the memcpy to loads and stores first. +  // For cases within the target-specified limits, this is the best choice. +  ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size); +  if (ConstantSize) { +    // Memcpy with size zero? Just return the original chain. +    if (ConstantSize->isNullValue()) +      return Chain; + +    SDValue Result = getMemcpyLoadsAndStores(*this, dl, Chain, Dst, Src, +                                             ConstantSize->getZExtValue(),Align, +                                isVol, false, DstPtrInfo, SrcPtrInfo); +    if (Result.getNode()) +      return Result; +  } + +  // Then check to see if we should lower the memcpy with target-specific +  // code. If the target chooses to do this, this is the next best. +  if (TSI) { +    SDValue Result = TSI->EmitTargetCodeForMemcpy( +        *this, dl, Chain, Dst, Src, Size, Align, isVol, AlwaysInline, +        DstPtrInfo, SrcPtrInfo); +    if (Result.getNode()) +      return Result; +  } + +  // If we really need inline code and the target declined to provide it, +  // use a (potentially long) sequence of loads and stores. +  if (AlwaysInline) { +    assert(ConstantSize && "AlwaysInline requires a constant size!"); +    return getMemcpyLoadsAndStores(*this, dl, Chain, Dst, Src, +                                   ConstantSize->getZExtValue(), Align, isVol, +                                   true, DstPtrInfo, SrcPtrInfo); +  } + +  checkAddrSpaceIsValidForLibcall(TLI, DstPtrInfo.getAddrSpace()); +  checkAddrSpaceIsValidForLibcall(TLI, SrcPtrInfo.getAddrSpace()); + +  // FIXME: If the memcpy is volatile (isVol), lowering it to a plain libc +  // memcpy is not guaranteed to be safe. libc memcpys aren't required to +  // respect volatile, so they may do things like read or write memory +  // beyond the given memory regions. But fixing this isn't easy, and most +  // people don't care. + +  // Emit a library call. +  TargetLowering::ArgListTy Args; +  TargetLowering::ArgListEntry Entry; +  Entry.Ty = getDataLayout().getIntPtrType(*getContext()); +  Entry.Node = Dst; Args.push_back(Entry); +  Entry.Node = Src; Args.push_back(Entry); +  Entry.Node = Size; Args.push_back(Entry); +  // FIXME: pass in SDLoc +  TargetLowering::CallLoweringInfo CLI(*this); +  CLI.setDebugLoc(dl) +      .setChain(Chain) +      .setLibCallee(TLI->getLibcallCallingConv(RTLIB::MEMCPY), +                    Dst.getValueType().getTypeForEVT(*getContext()), +                    getExternalSymbol(TLI->getLibcallName(RTLIB::MEMCPY), +                                      TLI->getPointerTy(getDataLayout())), +                    std::move(Args)) +      .setDiscardResult() +      .setTailCall(isTailCall); + +  std::pair<SDValue,SDValue> CallResult = TLI->LowerCallTo(CLI); +  return CallResult.second; +} + +SDValue SelectionDAG::getMemmove(SDValue Chain, const SDLoc &dl, SDValue Dst, +                                 SDValue Src, SDValue Size, unsigned Align, +                                 bool isVol, bool isTailCall, +                                 MachinePointerInfo DstPtrInfo, +                                 MachinePointerInfo SrcPtrInfo) { +  assert(Align && "The SDAG layer expects explicit alignment and reserves 0"); + +  // Check to see if we should lower the memmove to loads and stores first. +  // For cases within the target-specified limits, this is the best choice. +  ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size); +  if (ConstantSize) { +    // Memmove with size zero? Just return the original chain. +    if (ConstantSize->isNullValue()) +      return Chain; + +    SDValue Result = +      getMemmoveLoadsAndStores(*this, dl, Chain, Dst, Src, +                               ConstantSize->getZExtValue(), Align, isVol, +                               false, DstPtrInfo, SrcPtrInfo); +    if (Result.getNode()) +      return Result; +  } + +  // Then check to see if we should lower the memmove with target-specific +  // code. If the target chooses to do this, this is the next best. +  if (TSI) { +    SDValue Result = TSI->EmitTargetCodeForMemmove( +        *this, dl, Chain, Dst, Src, Size, Align, isVol, DstPtrInfo, SrcPtrInfo); +    if (Result.getNode()) +      return Result; +  } + +  checkAddrSpaceIsValidForLibcall(TLI, DstPtrInfo.getAddrSpace()); +  checkAddrSpaceIsValidForLibcall(TLI, SrcPtrInfo.getAddrSpace()); + +  // FIXME: If the memmove is volatile, lowering it to plain libc memmove may +  // not be safe.  See memcpy above for more details. + +  // Emit a library call. +  TargetLowering::ArgListTy Args; +  TargetLowering::ArgListEntry Entry; +  Entry.Ty = getDataLayout().getIntPtrType(*getContext()); +  Entry.Node = Dst; Args.push_back(Entry); +  Entry.Node = Src; Args.push_back(Entry); +  Entry.Node = Size; Args.push_back(Entry); +  // FIXME:  pass in SDLoc +  TargetLowering::CallLoweringInfo CLI(*this); +  CLI.setDebugLoc(dl) +      .setChain(Chain) +      .setLibCallee(TLI->getLibcallCallingConv(RTLIB::MEMMOVE), +                    Dst.getValueType().getTypeForEVT(*getContext()), +                    getExternalSymbol(TLI->getLibcallName(RTLIB::MEMMOVE), +                                      TLI->getPointerTy(getDataLayout())), +                    std::move(Args)) +      .setDiscardResult() +      .setTailCall(isTailCall); + +  std::pair<SDValue,SDValue> CallResult = TLI->LowerCallTo(CLI); +  return CallResult.second; +} + +SDValue SelectionDAG::getMemset(SDValue Chain, const SDLoc &dl, SDValue Dst, +                                SDValue Src, SDValue Size, unsigned Align, +                                bool isVol, bool isTailCall, +                                MachinePointerInfo DstPtrInfo) { +  assert(Align && "The SDAG layer expects explicit alignment and reserves 0"); + +  // Check to see if we should lower the memset to stores first. +  // For cases within the target-specified limits, this is the best choice. +  ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size); +  if (ConstantSize) { +    // Memset with size zero? Just return the original chain. +    if (ConstantSize->isNullValue()) +      return Chain; + +    SDValue Result = +      getMemsetStores(*this, dl, Chain, Dst, Src, ConstantSize->getZExtValue(), +                      Align, isVol, DstPtrInfo); + +    if (Result.getNode()) +      return Result; +  } + +  // Then check to see if we should lower the memset with target-specific +  // code. If the target chooses to do this, this is the next best. +  if (TSI) { +    SDValue Result = TSI->EmitTargetCodeForMemset( +        *this, dl, Chain, Dst, Src, Size, Align, isVol, DstPtrInfo); +    if (Result.getNode()) +      return Result; +  } + +  checkAddrSpaceIsValidForLibcall(TLI, DstPtrInfo.getAddrSpace()); + +  // Emit a library call. +  Type *IntPtrTy = getDataLayout().getIntPtrType(*getContext()); +  TargetLowering::ArgListTy Args; +  TargetLowering::ArgListEntry Entry; +  Entry.Node = Dst; Entry.Ty = IntPtrTy; +  Args.push_back(Entry); +  Entry.Node = Src; +  Entry.Ty = Src.getValueType().getTypeForEVT(*getContext()); +  Args.push_back(Entry); +  Entry.Node = Size; +  Entry.Ty = IntPtrTy; +  Args.push_back(Entry); + +  // FIXME: pass in SDLoc +  TargetLowering::CallLoweringInfo CLI(*this); +  CLI.setDebugLoc(dl) +      .setChain(Chain) +      .setLibCallee(TLI->getLibcallCallingConv(RTLIB::MEMSET), +                    Dst.getValueType().getTypeForEVT(*getContext()), +                    getExternalSymbol(TLI->getLibcallName(RTLIB::MEMSET), +                                      TLI->getPointerTy(getDataLayout())), +                    std::move(Args)) +      .setDiscardResult() +      .setTailCall(isTailCall); + +  std::pair<SDValue,SDValue> CallResult = TLI->LowerCallTo(CLI); +  return CallResult.second; +} + +SDValue SelectionDAG::getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT, +                                SDVTList VTList, ArrayRef<SDValue> Ops, +                                MachineMemOperand *MMO) { +  FoldingSetNodeID ID; +  ID.AddInteger(MemVT.getRawBits()); +  AddNodeIDNode(ID, Opcode, VTList, Ops); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void* IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<AtomicSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } + +  auto *N = newSDNode<AtomicSDNode>(Opcode, dl.getIROrder(), dl.getDebugLoc(), +                                    VTList, MemVT, MMO); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getAtomicCmpSwap( +    unsigned Opcode, const SDLoc &dl, EVT MemVT, SDVTList VTs, SDValue Chain, +    SDValue Ptr, SDValue Cmp, SDValue Swp, MachinePointerInfo PtrInfo, +    unsigned Alignment, AtomicOrdering SuccessOrdering, +    AtomicOrdering FailureOrdering, SynchronizationScope SynchScope) { +  assert(Opcode == ISD::ATOMIC_CMP_SWAP || +         Opcode == ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS); +  assert(Cmp.getValueType() == Swp.getValueType() && "Invalid Atomic Op Types"); + +  if (Alignment == 0)  // Ensure that codegen never sees alignment 0 +    Alignment = getEVTAlignment(MemVT); + +  MachineFunction &MF = getMachineFunction(); + +  // FIXME: Volatile isn't really correct; we should keep track of atomic +  // orderings in the memoperand. +  auto Flags = MachineMemOperand::MOVolatile | MachineMemOperand::MOLoad | +               MachineMemOperand::MOStore; +  MachineMemOperand *MMO = +    MF.getMachineMemOperand(PtrInfo, Flags, MemVT.getStoreSize(), Alignment, +                            AAMDNodes(), nullptr, SynchScope, SuccessOrdering, +                            FailureOrdering); + +  return getAtomicCmpSwap(Opcode, dl, MemVT, VTs, Chain, Ptr, Cmp, Swp, MMO); +} + +SDValue SelectionDAG::getAtomicCmpSwap(unsigned Opcode, const SDLoc &dl, +                                       EVT MemVT, SDVTList VTs, SDValue Chain, +                                       SDValue Ptr, SDValue Cmp, SDValue Swp, +                                       MachineMemOperand *MMO) { +  assert(Opcode == ISD::ATOMIC_CMP_SWAP || +         Opcode == ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS); +  assert(Cmp.getValueType() == Swp.getValueType() && "Invalid Atomic Op Types"); + +  SDValue Ops[] = {Chain, Ptr, Cmp, Swp}; +  return getAtomic(Opcode, dl, MemVT, VTs, Ops, MMO); +} + +SDValue SelectionDAG::getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT, +                                SDValue Chain, SDValue Ptr, SDValue Val, +                                const Value *PtrVal, unsigned Alignment, +                                AtomicOrdering Ordering, +                                SynchronizationScope SynchScope) { +  if (Alignment == 0)  // Ensure that codegen never sees alignment 0 +    Alignment = getEVTAlignment(MemVT); + +  MachineFunction &MF = getMachineFunction(); +  // An atomic store does not load. An atomic load does not store. +  // (An atomicrmw obviously both loads and stores.) +  // For now, atomics are considered to be volatile always, and they are +  // chained as such. +  // FIXME: Volatile isn't really correct; we should keep track of atomic +  // orderings in the memoperand. +  auto Flags = MachineMemOperand::MOVolatile; +  if (Opcode != ISD::ATOMIC_STORE) +    Flags |= MachineMemOperand::MOLoad; +  if (Opcode != ISD::ATOMIC_LOAD) +    Flags |= MachineMemOperand::MOStore; + +  MachineMemOperand *MMO = +    MF.getMachineMemOperand(MachinePointerInfo(PtrVal), Flags, +                            MemVT.getStoreSize(), Alignment, AAMDNodes(), +                            nullptr, SynchScope, Ordering); + +  return getAtomic(Opcode, dl, MemVT, Chain, Ptr, Val, MMO); +} + +SDValue SelectionDAG::getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT, +                                SDValue Chain, SDValue Ptr, SDValue Val, +                                MachineMemOperand *MMO) { +  assert((Opcode == ISD::ATOMIC_LOAD_ADD || +          Opcode == ISD::ATOMIC_LOAD_SUB || +          Opcode == ISD::ATOMIC_LOAD_AND || +          Opcode == ISD::ATOMIC_LOAD_OR || +          Opcode == ISD::ATOMIC_LOAD_XOR || +          Opcode == ISD::ATOMIC_LOAD_NAND || +          Opcode == ISD::ATOMIC_LOAD_MIN || +          Opcode == ISD::ATOMIC_LOAD_MAX || +          Opcode == ISD::ATOMIC_LOAD_UMIN || +          Opcode == ISD::ATOMIC_LOAD_UMAX || +          Opcode == ISD::ATOMIC_SWAP || +          Opcode == ISD::ATOMIC_STORE) && +         "Invalid Atomic Op"); + +  EVT VT = Val.getValueType(); + +  SDVTList VTs = Opcode == ISD::ATOMIC_STORE ? getVTList(MVT::Other) : +                                               getVTList(VT, MVT::Other); +  SDValue Ops[] = {Chain, Ptr, Val}; +  return getAtomic(Opcode, dl, MemVT, VTs, Ops, MMO); +} + +SDValue SelectionDAG::getAtomic(unsigned Opcode, const SDLoc &dl, EVT MemVT, +                                EVT VT, SDValue Chain, SDValue Ptr, +                                MachineMemOperand *MMO) { +  assert(Opcode == ISD::ATOMIC_LOAD && "Invalid Atomic Op"); + +  SDVTList VTs = getVTList(VT, MVT::Other); +  SDValue Ops[] = {Chain, Ptr}; +  return getAtomic(Opcode, dl, MemVT, VTs, Ops, MMO); +} + +/// getMergeValues - Create a MERGE_VALUES node from the given operands. +SDValue SelectionDAG::getMergeValues(ArrayRef<SDValue> Ops, const SDLoc &dl) { +  if (Ops.size() == 1) +    return Ops[0]; + +  SmallVector<EVT, 4> VTs; +  VTs.reserve(Ops.size()); +  for (unsigned i = 0; i < Ops.size(); ++i) +    VTs.push_back(Ops[i].getValueType()); +  return getNode(ISD::MERGE_VALUES, dl, getVTList(VTs), Ops); +} + +SDValue SelectionDAG::getMemIntrinsicNode( +    unsigned Opcode, const SDLoc &dl, SDVTList VTList, ArrayRef<SDValue> Ops, +    EVT MemVT, MachinePointerInfo PtrInfo, unsigned Align, bool Vol, +    bool ReadMem, bool WriteMem, unsigned Size) { +  if (Align == 0)  // Ensure that codegen never sees alignment 0 +    Align = getEVTAlignment(MemVT); + +  MachineFunction &MF = getMachineFunction(); +  auto Flags = MachineMemOperand::MONone; +  if (WriteMem) +    Flags |= MachineMemOperand::MOStore; +  if (ReadMem) +    Flags |= MachineMemOperand::MOLoad; +  if (Vol) +    Flags |= MachineMemOperand::MOVolatile; +  if (!Size) +    Size = MemVT.getStoreSize(); +  MachineMemOperand *MMO = +    MF.getMachineMemOperand(PtrInfo, Flags, Size, Align); + +  return getMemIntrinsicNode(Opcode, dl, VTList, Ops, MemVT, MMO); +} + +SDValue SelectionDAG::getMemIntrinsicNode(unsigned Opcode, const SDLoc &dl, +                                          SDVTList VTList, +                                          ArrayRef<SDValue> Ops, EVT MemVT, +                                          MachineMemOperand *MMO) { +  assert((Opcode == ISD::INTRINSIC_VOID || +          Opcode == ISD::INTRINSIC_W_CHAIN || +          Opcode == ISD::PREFETCH || +          Opcode == ISD::LIFETIME_START || +          Opcode == ISD::LIFETIME_END || +          ((int)Opcode <= std::numeric_limits<int>::max() && +           (int)Opcode >= ISD::FIRST_TARGET_MEMORY_OPCODE)) && +         "Opcode is not a memory-accessing opcode!"); + +  // Memoize the node unless it returns a flag. +  MemIntrinsicSDNode *N; +  if (VTList.VTs[VTList.NumVTs-1] != MVT::Glue) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opcode, VTList, Ops); +    ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +    void *IP = nullptr; +    if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +      cast<MemIntrinsicSDNode>(E)->refineAlignment(MMO); +      return SDValue(E, 0); +    } + +    N = newSDNode<MemIntrinsicSDNode>(Opcode, dl.getIROrder(), dl.getDebugLoc(), +                                      VTList, MemVT, MMO); +    createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  } else { +    N = newSDNode<MemIntrinsicSDNode>(Opcode, dl.getIROrder(), dl.getDebugLoc(), +                                      VTList, MemVT, MMO); +    createOperands(N, Ops); +  } +  InsertNode(N); +  return SDValue(N, 0); +} + +/// InferPointerInfo - If the specified ptr/offset is a frame index, infer a +/// MachinePointerInfo record from it.  This is particularly useful because the +/// code generator has many cases where it doesn't bother passing in a +/// MachinePointerInfo to getLoad or getStore when it has "FI+Cst". +static MachinePointerInfo InferPointerInfo(SelectionDAG &DAG, SDValue Ptr, +                                           int64_t Offset = 0) { +  // If this is FI+Offset, we can model it. +  if (const FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Ptr)) +    return MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), +                                             FI->getIndex(), Offset); + +  // If this is (FI+Offset1)+Offset2, we can model it. +  if (Ptr.getOpcode() != ISD::ADD || +      !isa<ConstantSDNode>(Ptr.getOperand(1)) || +      !isa<FrameIndexSDNode>(Ptr.getOperand(0))) +    return MachinePointerInfo(); + +  int FI = cast<FrameIndexSDNode>(Ptr.getOperand(0))->getIndex(); +  return MachinePointerInfo::getFixedStack( +      DAG.getMachineFunction(), FI, +      Offset + cast<ConstantSDNode>(Ptr.getOperand(1))->getSExtValue()); +} + +/// InferPointerInfo - If the specified ptr/offset is a frame index, infer a +/// MachinePointerInfo record from it.  This is particularly useful because the +/// code generator has many cases where it doesn't bother passing in a +/// MachinePointerInfo to getLoad or getStore when it has "FI+Cst". +static MachinePointerInfo InferPointerInfo(SelectionDAG &DAG, SDValue Ptr, +                                           SDValue OffsetOp) { +  // If the 'Offset' value isn't a constant, we can't handle this. +  if (ConstantSDNode *OffsetNode = dyn_cast<ConstantSDNode>(OffsetOp)) +    return InferPointerInfo(DAG, Ptr, OffsetNode->getSExtValue()); +  if (OffsetOp.isUndef()) +    return InferPointerInfo(DAG, Ptr); +  return MachinePointerInfo(); +} + +SDValue SelectionDAG::getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, +                              EVT VT, const SDLoc &dl, SDValue Chain, +                              SDValue Ptr, SDValue Offset, +                              MachinePointerInfo PtrInfo, EVT MemVT, +                              unsigned Alignment, +                              MachineMemOperand::Flags MMOFlags, +                              const AAMDNodes &AAInfo, const MDNode *Ranges) { +  assert(Chain.getValueType() == MVT::Other && +        "Invalid chain type"); +  if (Alignment == 0)  // Ensure that codegen never sees alignment 0 +    Alignment = getEVTAlignment(MemVT); + +  MMOFlags |= MachineMemOperand::MOLoad; +  assert((MMOFlags & MachineMemOperand::MOStore) == 0); +  // If we don't have a PtrInfo, infer the trivial frame index case to simplify +  // clients. +  if (PtrInfo.V.isNull()) +    PtrInfo = InferPointerInfo(*this, Ptr, Offset); + +  MachineFunction &MF = getMachineFunction(); +  MachineMemOperand *MMO = MF.getMachineMemOperand( +      PtrInfo, MMOFlags, MemVT.getStoreSize(), Alignment, AAInfo, Ranges); +  return getLoad(AM, ExtType, VT, dl, Chain, Ptr, Offset, MemVT, MMO); +} + +SDValue SelectionDAG::getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, +                              EVT VT, const SDLoc &dl, SDValue Chain, +                              SDValue Ptr, SDValue Offset, EVT MemVT, +                              MachineMemOperand *MMO) { +  if (VT == MemVT) { +    ExtType = ISD::NON_EXTLOAD; +  } else if (ExtType == ISD::NON_EXTLOAD) { +    assert(VT == MemVT && "Non-extending load from different memory type!"); +  } else { +    // Extending load. +    assert(MemVT.getScalarType().bitsLT(VT.getScalarType()) && +           "Should only be an extending load, not truncating!"); +    assert(VT.isInteger() == MemVT.isInteger() && +           "Cannot convert from FP to Int or Int -> FP!"); +    assert(VT.isVector() == MemVT.isVector() && +           "Cannot use an ext load to convert to or from a vector!"); +    assert((!VT.isVector() || +            VT.getVectorNumElements() == MemVT.getVectorNumElements()) && +           "Cannot use an ext load to change the number of vector elements!"); +  } + +  bool Indexed = AM != ISD::UNINDEXED; +  assert((Indexed || Offset.isUndef()) && "Unindexed load with an offset!"); + +  SDVTList VTs = Indexed ? +    getVTList(VT, Ptr.getValueType(), MVT::Other) : getVTList(VT, MVT::Other); +  SDValue Ops[] = { Chain, Ptr, Offset }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::LOAD, VTs, Ops); +  ID.AddInteger(MemVT.getRawBits()); +  ID.AddInteger(getSyntheticNodeSubclassData<LoadSDNode>( +      dl.getIROrder(), VTs, AM, ExtType, MemVT, MMO)); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<LoadSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } +  auto *N = newSDNode<LoadSDNode>(dl.getIROrder(), dl.getDebugLoc(), VTs, AM, +                                  ExtType, MemVT, MMO); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getLoad(EVT VT, const SDLoc &dl, SDValue Chain, +                              SDValue Ptr, MachinePointerInfo PtrInfo, +                              unsigned Alignment, +                              MachineMemOperand::Flags MMOFlags, +                              const AAMDNodes &AAInfo, const MDNode *Ranges) { +  SDValue Undef = getUNDEF(Ptr.getValueType()); +  return getLoad(ISD::UNINDEXED, ISD::NON_EXTLOAD, VT, dl, Chain, Ptr, Undef, +                 PtrInfo, VT, Alignment, MMOFlags, AAInfo, Ranges); +} + +SDValue SelectionDAG::getLoad(EVT VT, const SDLoc &dl, SDValue Chain, +                              SDValue Ptr, MachineMemOperand *MMO) { +  SDValue Undef = getUNDEF(Ptr.getValueType()); +  return getLoad(ISD::UNINDEXED, ISD::NON_EXTLOAD, VT, dl, Chain, Ptr, Undef, +                 VT, MMO); +} + +SDValue SelectionDAG::getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl, +                                 EVT VT, SDValue Chain, SDValue Ptr, +                                 MachinePointerInfo PtrInfo, EVT MemVT, +                                 unsigned Alignment, +                                 MachineMemOperand::Flags MMOFlags, +                                 const AAMDNodes &AAInfo) { +  SDValue Undef = getUNDEF(Ptr.getValueType()); +  return getLoad(ISD::UNINDEXED, ExtType, VT, dl, Chain, Ptr, Undef, PtrInfo, +                 MemVT, Alignment, MMOFlags, AAInfo); +} + +SDValue SelectionDAG::getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl, +                                 EVT VT, SDValue Chain, SDValue Ptr, EVT MemVT, +                                 MachineMemOperand *MMO) { +  SDValue Undef = getUNDEF(Ptr.getValueType()); +  return getLoad(ISD::UNINDEXED, ExtType, VT, dl, Chain, Ptr, Undef, +                 MemVT, MMO); +} + +SDValue SelectionDAG::getIndexedLoad(SDValue OrigLoad, const SDLoc &dl, +                                     SDValue Base, SDValue Offset, +                                     ISD::MemIndexedMode AM) { +  LoadSDNode *LD = cast<LoadSDNode>(OrigLoad); +  assert(LD->getOffset().isUndef() && "Load is already a indexed load!"); +  // Don't propagate the invariant or dereferenceable flags. +  auto MMOFlags = +      LD->getMemOperand()->getFlags() & +      ~(MachineMemOperand::MOInvariant | MachineMemOperand::MODereferenceable); +  return getLoad(AM, LD->getExtensionType(), OrigLoad.getValueType(), dl, +                 LD->getChain(), Base, Offset, LD->getPointerInfo(), +                 LD->getMemoryVT(), LD->getAlignment(), MMOFlags, +                 LD->getAAInfo()); +} + +SDValue SelectionDAG::getStore(SDValue Chain, const SDLoc &dl, SDValue Val, +                               SDValue Ptr, MachinePointerInfo PtrInfo, +                               unsigned Alignment, +                               MachineMemOperand::Flags MMOFlags, +                               const AAMDNodes &AAInfo) { +  assert(Chain.getValueType() == MVT::Other && "Invalid chain type"); +  if (Alignment == 0)  // Ensure that codegen never sees alignment 0 +    Alignment = getEVTAlignment(Val.getValueType()); + +  MMOFlags |= MachineMemOperand::MOStore; +  assert((MMOFlags & MachineMemOperand::MOLoad) == 0); + +  if (PtrInfo.V.isNull()) +    PtrInfo = InferPointerInfo(*this, Ptr); + +  MachineFunction &MF = getMachineFunction(); +  MachineMemOperand *MMO = MF.getMachineMemOperand( +      PtrInfo, MMOFlags, Val.getValueType().getStoreSize(), Alignment, AAInfo); +  return getStore(Chain, dl, Val, Ptr, MMO); +} + +SDValue SelectionDAG::getStore(SDValue Chain, const SDLoc &dl, SDValue Val, +                               SDValue Ptr, MachineMemOperand *MMO) { +  assert(Chain.getValueType() == MVT::Other && +        "Invalid chain type"); +  EVT VT = Val.getValueType(); +  SDVTList VTs = getVTList(MVT::Other); +  SDValue Undef = getUNDEF(Ptr.getValueType()); +  SDValue Ops[] = { Chain, Val, Ptr, Undef }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::STORE, VTs, Ops); +  ID.AddInteger(VT.getRawBits()); +  ID.AddInteger(getSyntheticNodeSubclassData<StoreSDNode>( +      dl.getIROrder(), VTs, ISD::UNINDEXED, false, VT, MMO)); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<StoreSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } +  auto *N = newSDNode<StoreSDNode>(dl.getIROrder(), dl.getDebugLoc(), VTs, +                                   ISD::UNINDEXED, false, VT, MMO); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, +                                    SDValue Ptr, MachinePointerInfo PtrInfo, +                                    EVT SVT, unsigned Alignment, +                                    MachineMemOperand::Flags MMOFlags, +                                    const AAMDNodes &AAInfo) { +  assert(Chain.getValueType() == MVT::Other && +        "Invalid chain type"); +  if (Alignment == 0)  // Ensure that codegen never sees alignment 0 +    Alignment = getEVTAlignment(SVT); + +  MMOFlags |= MachineMemOperand::MOStore; +  assert((MMOFlags & MachineMemOperand::MOLoad) == 0); + +  if (PtrInfo.V.isNull()) +    PtrInfo = InferPointerInfo(*this, Ptr); + +  MachineFunction &MF = getMachineFunction(); +  MachineMemOperand *MMO = MF.getMachineMemOperand( +      PtrInfo, MMOFlags, SVT.getStoreSize(), Alignment, AAInfo); +  return getTruncStore(Chain, dl, Val, Ptr, SVT, MMO); +} + +SDValue SelectionDAG::getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, +                                    SDValue Ptr, EVT SVT, +                                    MachineMemOperand *MMO) { +  EVT VT = Val.getValueType(); + +  assert(Chain.getValueType() == MVT::Other && +        "Invalid chain type"); +  if (VT == SVT) +    return getStore(Chain, dl, Val, Ptr, MMO); + +  assert(SVT.getScalarType().bitsLT(VT.getScalarType()) && +         "Should only be a truncating store, not extending!"); +  assert(VT.isInteger() == SVT.isInteger() && +         "Can't do FP-INT conversion!"); +  assert(VT.isVector() == SVT.isVector() && +         "Cannot use trunc store to convert to or from a vector!"); +  assert((!VT.isVector() || +          VT.getVectorNumElements() == SVT.getVectorNumElements()) && +         "Cannot use trunc store to change the number of vector elements!"); + +  SDVTList VTs = getVTList(MVT::Other); +  SDValue Undef = getUNDEF(Ptr.getValueType()); +  SDValue Ops[] = { Chain, Val, Ptr, Undef }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::STORE, VTs, Ops); +  ID.AddInteger(SVT.getRawBits()); +  ID.AddInteger(getSyntheticNodeSubclassData<StoreSDNode>( +      dl.getIROrder(), VTs, ISD::UNINDEXED, true, SVT, MMO)); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<StoreSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } +  auto *N = newSDNode<StoreSDNode>(dl.getIROrder(), dl.getDebugLoc(), VTs, +                                   ISD::UNINDEXED, true, SVT, MMO); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getIndexedStore(SDValue OrigStore, const SDLoc &dl, +                                      SDValue Base, SDValue Offset, +                                      ISD::MemIndexedMode AM) { +  StoreSDNode *ST = cast<StoreSDNode>(OrigStore); +  assert(ST->getOffset().isUndef() && "Store is already a indexed store!"); +  SDVTList VTs = getVTList(Base.getValueType(), MVT::Other); +  SDValue Ops[] = { ST->getChain(), ST->getValue(), Base, Offset }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::STORE, VTs, Ops); +  ID.AddInteger(ST->getMemoryVT().getRawBits()); +  ID.AddInteger(ST->getRawSubclassData()); +  ID.AddInteger(ST->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) +    return SDValue(E, 0); + +  auto *N = newSDNode<StoreSDNode>(dl.getIROrder(), dl.getDebugLoc(), VTs, AM, +                                   ST->isTruncatingStore(), ST->getMemoryVT(), +                                   ST->getMemOperand()); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getMaskedLoad(EVT VT, const SDLoc &dl, SDValue Chain, +                                    SDValue Ptr, SDValue Mask, SDValue Src0, +                                    EVT MemVT, MachineMemOperand *MMO, +                                    ISD::LoadExtType ExtTy, bool isExpanding) { +  SDVTList VTs = getVTList(VT, MVT::Other); +  SDValue Ops[] = { Chain, Ptr, Mask, Src0 }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::MLOAD, VTs, Ops); +  ID.AddInteger(VT.getRawBits()); +  ID.AddInteger(getSyntheticNodeSubclassData<MaskedLoadSDNode>( +      dl.getIROrder(), VTs, ExtTy, isExpanding, MemVT, MMO)); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<MaskedLoadSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } +  auto *N = newSDNode<MaskedLoadSDNode>(dl.getIROrder(), dl.getDebugLoc(), VTs, +                                        ExtTy, isExpanding, MemVT, MMO); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getMaskedStore(SDValue Chain, const SDLoc &dl, +                                     SDValue Val, SDValue Ptr, SDValue Mask, +                                     EVT MemVT, MachineMemOperand *MMO, +                                     bool IsTruncating, bool IsCompressing) { +  assert(Chain.getValueType() == MVT::Other && +        "Invalid chain type"); +  EVT VT = Val.getValueType(); +  SDVTList VTs = getVTList(MVT::Other); +  SDValue Ops[] = { Chain, Ptr, Mask, Val }; +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::MSTORE, VTs, Ops); +  ID.AddInteger(VT.getRawBits()); +  ID.AddInteger(getSyntheticNodeSubclassData<MaskedStoreSDNode>( +      dl.getIROrder(), VTs, IsTruncating, IsCompressing, MemVT, MMO)); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<MaskedStoreSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } +  auto *N = newSDNode<MaskedStoreSDNode>(dl.getIROrder(), dl.getDebugLoc(), VTs, +                                         IsTruncating, IsCompressing, MemVT, MMO); +  createOperands(N, Ops); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getMaskedGather(SDVTList VTs, EVT VT, const SDLoc &dl, +                                      ArrayRef<SDValue> Ops, +                                      MachineMemOperand *MMO) { +  assert(Ops.size() == 5 && "Incompatible number of operands"); + +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::MGATHER, VTs, Ops); +  ID.AddInteger(VT.getRawBits()); +  ID.AddInteger(getSyntheticNodeSubclassData<MaskedGatherSDNode>( +      dl.getIROrder(), VTs, VT, MMO)); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<MaskedGatherSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } + +  auto *N = newSDNode<MaskedGatherSDNode>(dl.getIROrder(), dl.getDebugLoc(), +                                          VTs, VT, MMO); +  createOperands(N, Ops); + +  assert(N->getValue().getValueType() == N->getValueType(0) && +         "Incompatible type of the PassThru value in MaskedGatherSDNode"); +  assert(N->getMask().getValueType().getVectorNumElements() == +             N->getValueType(0).getVectorNumElements() && +         "Vector width mismatch between mask and data"); +  assert(N->getIndex().getValueType().getVectorNumElements() == +             N->getValueType(0).getVectorNumElements() && +         "Vector width mismatch between index and data"); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getMaskedScatter(SDVTList VTs, EVT VT, const SDLoc &dl, +                                       ArrayRef<SDValue> Ops, +                                       MachineMemOperand *MMO) { +  assert(Ops.size() == 5 && "Incompatible number of operands"); + +  FoldingSetNodeID ID; +  AddNodeIDNode(ID, ISD::MSCATTER, VTs, Ops); +  ID.AddInteger(VT.getRawBits()); +  ID.AddInteger(getSyntheticNodeSubclassData<MaskedScatterSDNode>( +      dl.getIROrder(), VTs, VT, MMO)); +  ID.AddInteger(MMO->getPointerInfo().getAddrSpace()); +  void *IP = nullptr; +  if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP)) { +    cast<MaskedScatterSDNode>(E)->refineAlignment(MMO); +    return SDValue(E, 0); +  } +  auto *N = newSDNode<MaskedScatterSDNode>(dl.getIROrder(), dl.getDebugLoc(), +                                           VTs, VT, MMO); +  createOperands(N, Ops); + +  assert(N->getMask().getValueType().getVectorNumElements() == +             N->getValue().getValueType().getVectorNumElements() && +         "Vector width mismatch between mask and data"); +  assert(N->getIndex().getValueType().getVectorNumElements() == +             N->getValue().getValueType().getVectorNumElements() && +         "Vector width mismatch between index and data"); + +  CSEMap.InsertNode(N, IP); +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getVAArg(EVT VT, const SDLoc &dl, SDValue Chain, +                               SDValue Ptr, SDValue SV, unsigned Align) { +  SDValue Ops[] = { Chain, Ptr, SV, getTargetConstant(Align, dl, MVT::i32) }; +  return getNode(ISD::VAARG, dl, getVTList(VT, MVT::Other), Ops); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, +                              ArrayRef<SDUse> Ops) { +  switch (Ops.size()) { +  case 0: return getNode(Opcode, DL, VT); +  case 1: return getNode(Opcode, DL, VT, static_cast<const SDValue>(Ops[0])); +  case 2: return getNode(Opcode, DL, VT, Ops[0], Ops[1]); +  case 3: return getNode(Opcode, DL, VT, Ops[0], Ops[1], Ops[2]); +  default: break; +  } + +  // Copy from an SDUse array into an SDValue array for use with +  // the regular getNode logic. +  SmallVector<SDValue, 8> NewOps(Ops.begin(), Ops.end()); +  return getNode(Opcode, DL, VT, NewOps); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, +                              ArrayRef<SDValue> Ops, const SDNodeFlags Flags) { +  unsigned NumOps = Ops.size(); +  switch (NumOps) { +  case 0: return getNode(Opcode, DL, VT); +  case 1: return getNode(Opcode, DL, VT, Ops[0], Flags); +  case 2: return getNode(Opcode, DL, VT, Ops[0], Ops[1], Flags); +  case 3: return getNode(Opcode, DL, VT, Ops[0], Ops[1], Ops[2]); +  default: break; +  } + +  switch (Opcode) { +  default: break; +  case ISD::CONCAT_VECTORS: +    // Attempt to fold CONCAT_VECTORS into BUILD_VECTOR or UNDEF. +    if (SDValue V = FoldCONCAT_VECTORS(DL, VT, Ops, *this)) +      return V; +    break; +  case ISD::SELECT_CC: +    assert(NumOps == 5 && "SELECT_CC takes 5 operands!"); +    assert(Ops[0].getValueType() == Ops[1].getValueType() && +           "LHS and RHS of condition must have same type!"); +    assert(Ops[2].getValueType() == Ops[3].getValueType() && +           "True and False arms of SelectCC must have same type!"); +    assert(Ops[2].getValueType() == VT && +           "select_cc node must be of same type as true and false value!"); +    break; +  case ISD::BR_CC: +    assert(NumOps == 5 && "BR_CC takes 5 operands!"); +    assert(Ops[2].getValueType() == Ops[3].getValueType() && +           "LHS/RHS of comparison should match types!"); +    break; +  } + +  // Memoize nodes. +  SDNode *N; +  SDVTList VTs = getVTList(VT); + +  if (VT != MVT::Glue) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opcode, VTs, Ops); +    void *IP = nullptr; + +    if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) +      return SDValue(E, 0); + +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    createOperands(N, Ops); + +    CSEMap.InsertNode(N, IP); +  } else { +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +    createOperands(N, Ops); +  } + +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, +                              ArrayRef<EVT> ResultTys, ArrayRef<SDValue> Ops) { +  return getNode(Opcode, DL, getVTList(ResultTys), Ops); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, +                              ArrayRef<SDValue> Ops) { +  if (VTList.NumVTs == 1) +    return getNode(Opcode, DL, VTList.VTs[0], Ops); + +#if 0 +  switch (Opcode) { +  // FIXME: figure out how to safely handle things like +  // int foo(int x) { return 1 << (x & 255); } +  // int bar() { return foo(256); } +  case ISD::SRA_PARTS: +  case ISD::SRL_PARTS: +  case ISD::SHL_PARTS: +    if (N3.getOpcode() == ISD::SIGN_EXTEND_INREG && +        cast<VTSDNode>(N3.getOperand(1))->getVT() != MVT::i1) +      return getNode(Opcode, DL, VT, N1, N2, N3.getOperand(0)); +    else if (N3.getOpcode() == ISD::AND) +      if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N3.getOperand(1))) { +        // If the and is only masking out bits that cannot effect the shift, +        // eliminate the and. +        unsigned NumBits = VT.getScalarSizeInBits()*2; +        if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1) +          return getNode(Opcode, DL, VT, N1, N2, N3.getOperand(0)); +      } +    break; +  } +#endif + +  // Memoize the node unless it returns a flag. +  SDNode *N; +  if (VTList.VTs[VTList.NumVTs-1] != MVT::Glue) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opcode, VTList, Ops); +    void *IP = nullptr; +    if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) +      return SDValue(E, 0); + +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTList); +    createOperands(N, Ops); +    CSEMap.InsertNode(N, IP); +  } else { +    N = newSDNode<SDNode>(Opcode, DL.getIROrder(), DL.getDebugLoc(), VTList); +    createOperands(N, Ops); +  } +  InsertNode(N); +  return SDValue(N, 0); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, +                              SDVTList VTList) { +  return getNode(Opcode, DL, VTList, None); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, +                              SDValue N1) { +  SDValue Ops[] = { N1 }; +  return getNode(Opcode, DL, VTList, Ops); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, +                              SDValue N1, SDValue N2) { +  SDValue Ops[] = { N1, N2 }; +  return getNode(Opcode, DL, VTList, Ops); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, +                              SDValue N1, SDValue N2, SDValue N3) { +  SDValue Ops[] = { N1, N2, N3 }; +  return getNode(Opcode, DL, VTList, Ops); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, +                              SDValue N1, SDValue N2, SDValue N3, SDValue N4) { +  SDValue Ops[] = { N1, N2, N3, N4 }; +  return getNode(Opcode, DL, VTList, Ops); +} + +SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList, +                              SDValue N1, SDValue N2, SDValue N3, SDValue N4, +                              SDValue N5) { +  SDValue Ops[] = { N1, N2, N3, N4, N5 }; +  return getNode(Opcode, DL, VTList, Ops); +} + +SDVTList SelectionDAG::getVTList(EVT VT) { +  return makeVTList(SDNode::getValueTypeList(VT), 1); +} + +SDVTList SelectionDAG::getVTList(EVT VT1, EVT VT2) { +  FoldingSetNodeID ID; +  ID.AddInteger(2U); +  ID.AddInteger(VT1.getRawBits()); +  ID.AddInteger(VT2.getRawBits()); + +  void *IP = nullptr; +  SDVTListNode *Result = VTListMap.FindNodeOrInsertPos(ID, IP); +  if (!Result) { +    EVT *Array = Allocator.Allocate<EVT>(2); +    Array[0] = VT1; +    Array[1] = VT2; +    Result = new (Allocator) SDVTListNode(ID.Intern(Allocator), Array, 2); +    VTListMap.InsertNode(Result, IP); +  } +  return Result->getSDVTList(); +} + +SDVTList SelectionDAG::getVTList(EVT VT1, EVT VT2, EVT VT3) { +  FoldingSetNodeID ID; +  ID.AddInteger(3U); +  ID.AddInteger(VT1.getRawBits()); +  ID.AddInteger(VT2.getRawBits()); +  ID.AddInteger(VT3.getRawBits()); + +  void *IP = nullptr; +  SDVTListNode *Result = VTListMap.FindNodeOrInsertPos(ID, IP); +  if (!Result) { +    EVT *Array = Allocator.Allocate<EVT>(3); +    Array[0] = VT1; +    Array[1] = VT2; +    Array[2] = VT3; +    Result = new (Allocator) SDVTListNode(ID.Intern(Allocator), Array, 3); +    VTListMap.InsertNode(Result, IP); +  } +  return Result->getSDVTList(); +} + +SDVTList SelectionDAG::getVTList(EVT VT1, EVT VT2, EVT VT3, EVT VT4) { +  FoldingSetNodeID ID; +  ID.AddInteger(4U); +  ID.AddInteger(VT1.getRawBits()); +  ID.AddInteger(VT2.getRawBits()); +  ID.AddInteger(VT3.getRawBits()); +  ID.AddInteger(VT4.getRawBits()); + +  void *IP = nullptr; +  SDVTListNode *Result = VTListMap.FindNodeOrInsertPos(ID, IP); +  if (!Result) { +    EVT *Array = Allocator.Allocate<EVT>(4); +    Array[0] = VT1; +    Array[1] = VT2; +    Array[2] = VT3; +    Array[3] = VT4; +    Result = new (Allocator) SDVTListNode(ID.Intern(Allocator), Array, 4); +    VTListMap.InsertNode(Result, IP); +  } +  return Result->getSDVTList(); +} + +SDVTList SelectionDAG::getVTList(ArrayRef<EVT> VTs) { +  unsigned NumVTs = VTs.size(); +  FoldingSetNodeID ID; +  ID.AddInteger(NumVTs); +  for (unsigned index = 0; index < NumVTs; index++) { +    ID.AddInteger(VTs[index].getRawBits()); +  } + +  void *IP = nullptr; +  SDVTListNode *Result = VTListMap.FindNodeOrInsertPos(ID, IP); +  if (!Result) { +    EVT *Array = Allocator.Allocate<EVT>(NumVTs); +    std::copy(VTs.begin(), VTs.end(), Array); +    Result = new (Allocator) SDVTListNode(ID.Intern(Allocator), Array, NumVTs); +    VTListMap.InsertNode(Result, IP); +  } +  return Result->getSDVTList(); +} + + +/// UpdateNodeOperands - *Mutate* the specified node in-place to have the +/// specified operands.  If the resultant node already exists in the DAG, +/// this does not modify the specified node, instead it returns the node that +/// already exists.  If the resultant node does not exist in the DAG, the +/// input node is returned.  As a degenerate case, if you specify the same +/// input operands as the node already has, the input node is returned. +SDNode *SelectionDAG::UpdateNodeOperands(SDNode *N, SDValue Op) { +  assert(N->getNumOperands() == 1 && "Update with wrong number of operands"); + +  // Check to see if there is no change. +  if (Op == N->getOperand(0)) return N; + +  // See if the modified node already exists. +  void *InsertPos = nullptr; +  if (SDNode *Existing = FindModifiedNodeSlot(N, Op, InsertPos)) +    return Existing; + +  // Nope it doesn't.  Remove the node from its current place in the maps. +  if (InsertPos) +    if (!RemoveNodeFromCSEMaps(N)) +      InsertPos = nullptr; + +  // Now we update the operands. +  N->OperandList[0].set(Op); + +  // If this gets put into a CSE map, add it. +  if (InsertPos) CSEMap.InsertNode(N, InsertPos); +  return N; +} + +SDNode *SelectionDAG::UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2) { +  assert(N->getNumOperands() == 2 && "Update with wrong number of operands"); + +  // Check to see if there is no change. +  if (Op1 == N->getOperand(0) && Op2 == N->getOperand(1)) +    return N;   // No operands changed, just return the input node. + +  // See if the modified node already exists. +  void *InsertPos = nullptr; +  if (SDNode *Existing = FindModifiedNodeSlot(N, Op1, Op2, InsertPos)) +    return Existing; + +  // Nope it doesn't.  Remove the node from its current place in the maps. +  if (InsertPos) +    if (!RemoveNodeFromCSEMaps(N)) +      InsertPos = nullptr; + +  // Now we update the operands. +  if (N->OperandList[0] != Op1) +    N->OperandList[0].set(Op1); +  if (N->OperandList[1] != Op2) +    N->OperandList[1].set(Op2); + +  // If this gets put into a CSE map, add it. +  if (InsertPos) CSEMap.InsertNode(N, InsertPos); +  return N; +} + +SDNode *SelectionDAG:: +UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2, SDValue Op3) { +  SDValue Ops[] = { Op1, Op2, Op3 }; +  return UpdateNodeOperands(N, Ops); +} + +SDNode *SelectionDAG:: +UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2, +                   SDValue Op3, SDValue Op4) { +  SDValue Ops[] = { Op1, Op2, Op3, Op4 }; +  return UpdateNodeOperands(N, Ops); +} + +SDNode *SelectionDAG:: +UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2, +                   SDValue Op3, SDValue Op4, SDValue Op5) { +  SDValue Ops[] = { Op1, Op2, Op3, Op4, Op5 }; +  return UpdateNodeOperands(N, Ops); +} + +SDNode *SelectionDAG:: +UpdateNodeOperands(SDNode *N, ArrayRef<SDValue> Ops) { +  unsigned NumOps = Ops.size(); +  assert(N->getNumOperands() == NumOps && +         "Update with wrong number of operands"); + +  // If no operands changed just return the input node. +  if (std::equal(Ops.begin(), Ops.end(), N->op_begin())) +    return N; + +  // See if the modified node already exists. +  void *InsertPos = nullptr; +  if (SDNode *Existing = FindModifiedNodeSlot(N, Ops, InsertPos)) +    return Existing; + +  // Nope it doesn't.  Remove the node from its current place in the maps. +  if (InsertPos) +    if (!RemoveNodeFromCSEMaps(N)) +      InsertPos = nullptr; + +  // Now we update the operands. +  for (unsigned i = 0; i != NumOps; ++i) +    if (N->OperandList[i] != Ops[i]) +      N->OperandList[i].set(Ops[i]); + +  // If this gets put into a CSE map, add it. +  if (InsertPos) CSEMap.InsertNode(N, InsertPos); +  return N; +} + +/// DropOperands - Release the operands and set this node to have +/// zero operands. +void SDNode::DropOperands() { +  // Unlike the code in MorphNodeTo that does this, we don't need to +  // watch for dead nodes here. +  for (op_iterator I = op_begin(), E = op_end(); I != E; ) { +    SDUse &Use = *I++; +    Use.set(SDValue()); +  } +} + +/// SelectNodeTo - These are wrappers around MorphNodeTo that accept a +/// machine opcode. +/// +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT) { +  SDVTList VTs = getVTList(VT); +  return SelectNodeTo(N, MachineOpc, VTs, None); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT, SDValue Op1) { +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = { Op1 }; +  return SelectNodeTo(N, MachineOpc, VTs, Ops); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT, SDValue Op1, +                                   SDValue Op2) { +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = { Op1, Op2 }; +  return SelectNodeTo(N, MachineOpc, VTs, Ops); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT, SDValue Op1, +                                   SDValue Op2, SDValue Op3) { +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = { Op1, Op2, Op3 }; +  return SelectNodeTo(N, MachineOpc, VTs, Ops); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT, ArrayRef<SDValue> Ops) { +  SDVTList VTs = getVTList(VT); +  return SelectNodeTo(N, MachineOpc, VTs, Ops); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT1, EVT VT2, ArrayRef<SDValue> Ops) { +  SDVTList VTs = getVTList(VT1, VT2); +  return SelectNodeTo(N, MachineOpc, VTs, Ops); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT1, EVT VT2) { +  SDVTList VTs = getVTList(VT1, VT2); +  return SelectNodeTo(N, MachineOpc, VTs, None); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT1, EVT VT2, EVT VT3, +                                   ArrayRef<SDValue> Ops) { +  SDVTList VTs = getVTList(VT1, VT2, VT3); +  return SelectNodeTo(N, MachineOpc, VTs, Ops); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   EVT VT1, EVT VT2, +                                   SDValue Op1, SDValue Op2) { +  SDVTList VTs = getVTList(VT1, VT2); +  SDValue Ops[] = { Op1, Op2 }; +  return SelectNodeTo(N, MachineOpc, VTs, Ops); +} + +SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned MachineOpc, +                                   SDVTList VTs,ArrayRef<SDValue> Ops) { +  SDNode *New = MorphNodeTo(N, ~MachineOpc, VTs, Ops); +  // Reset the NodeID to -1. +  New->setNodeId(-1); +  if (New != N) { +    ReplaceAllUsesWith(N, New); +    RemoveDeadNode(N); +  } +  return New; +} + +/// UpdateSDLocOnMergeSDNode - If the opt level is -O0 then it throws away +/// the line number information on the merged node since it is not possible to +/// preserve the information that operation is associated with multiple lines. +/// This will make the debugger working better at -O0, were there is a higher +/// probability having other instructions associated with that line. +/// +/// For IROrder, we keep the smaller of the two +SDNode *SelectionDAG::UpdateSDLocOnMergeSDNode(SDNode *N, const SDLoc &OLoc) { +  DebugLoc NLoc = N->getDebugLoc(); +  if (NLoc && OptLevel == CodeGenOpt::None && OLoc.getDebugLoc() != NLoc) { +    N->setDebugLoc(DebugLoc()); +  } +  unsigned Order = std::min(N->getIROrder(), OLoc.getIROrder()); +  N->setIROrder(Order); +  return N; +} + +/// MorphNodeTo - This *mutates* the specified node to have the specified +/// return type, opcode, and operands. +/// +/// Note that MorphNodeTo returns the resultant node.  If there is already a +/// node of the specified opcode and operands, it returns that node instead of +/// the current one.  Note that the SDLoc need not be the same. +/// +/// Using MorphNodeTo is faster than creating a new node and swapping it in +/// with ReplaceAllUsesWith both because it often avoids allocating a new +/// node, and because it doesn't require CSE recalculation for any of +/// the node's users. +/// +/// However, note that MorphNodeTo recursively deletes dead nodes from the DAG. +/// As a consequence it isn't appropriate to use from within the DAG combiner or +/// the legalizer which maintain worklists that would need to be updated when +/// deleting things. +SDNode *SelectionDAG::MorphNodeTo(SDNode *N, unsigned Opc, +                                  SDVTList VTs, ArrayRef<SDValue> Ops) { +  // If an identical node already exists, use it. +  void *IP = nullptr; +  if (VTs.VTs[VTs.NumVTs-1] != MVT::Glue) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opc, VTs, Ops); +    if (SDNode *ON = FindNodeOrInsertPos(ID, SDLoc(N), IP)) +      return UpdateSDLocOnMergeSDNode(ON, SDLoc(N)); +  } + +  if (!RemoveNodeFromCSEMaps(N)) +    IP = nullptr; + +  // Start the morphing. +  N->NodeType = Opc; +  N->ValueList = VTs.VTs; +  N->NumValues = VTs.NumVTs; + +  // Clear the operands list, updating used nodes to remove this from their +  // use list.  Keep track of any operands that become dead as a result. +  SmallPtrSet<SDNode*, 16> DeadNodeSet; +  for (SDNode::op_iterator I = N->op_begin(), E = N->op_end(); I != E; ) { +    SDUse &Use = *I++; +    SDNode *Used = Use.getNode(); +    Use.set(SDValue()); +    if (Used->use_empty()) +      DeadNodeSet.insert(Used); +  } + +  // For MachineNode, initialize the memory references information. +  if (MachineSDNode *MN = dyn_cast<MachineSDNode>(N)) +    MN->setMemRefs(nullptr, nullptr); + +  // Swap for an appropriately sized array from the recycler. +  removeOperands(N); +  createOperands(N, Ops); + +  // Delete any nodes that are still dead after adding the uses for the +  // new operands. +  if (!DeadNodeSet.empty()) { +    SmallVector<SDNode *, 16> DeadNodes; +    for (SDNode *N : DeadNodeSet) +      if (N->use_empty()) +        DeadNodes.push_back(N); +    RemoveDeadNodes(DeadNodes); +  } + +  if (IP) +    CSEMap.InsertNode(N, IP);   // Memoize the new node. +  return N; +} + +SDNode* SelectionDAG::mutateStrictFPToFP(SDNode *Node) { +  unsigned OrigOpc = Node->getOpcode(); +  unsigned NewOpc; +  bool IsUnary = false; +  switch (OrigOpc) { +  default:  +    llvm_unreachable("mutateStrictFPToFP called with unexpected opcode!"); +  case ISD::STRICT_FADD: NewOpc = ISD::FADD; break; +  case ISD::STRICT_FSUB: NewOpc = ISD::FSUB; break; +  case ISD::STRICT_FMUL: NewOpc = ISD::FMUL; break; +  case ISD::STRICT_FDIV: NewOpc = ISD::FDIV; break; +  case ISD::STRICT_FREM: NewOpc = ISD::FREM; break; +  case ISD::STRICT_FSQRT: NewOpc = ISD::FSQRT; IsUnary = true; break; +  case ISD::STRICT_FPOW: NewOpc = ISD::FPOW; break; +  case ISD::STRICT_FPOWI: NewOpc = ISD::FPOWI; break; +  case ISD::STRICT_FSIN: NewOpc = ISD::FSIN; IsUnary = true; break; +  case ISD::STRICT_FCOS: NewOpc = ISD::FCOS; IsUnary = true; break; +  case ISD::STRICT_FEXP: NewOpc = ISD::FEXP; IsUnary = true; break; +  case ISD::STRICT_FEXP2: NewOpc = ISD::FEXP2; IsUnary = true; break; +  case ISD::STRICT_FLOG: NewOpc = ISD::FLOG; IsUnary = true; break; +  case ISD::STRICT_FLOG10: NewOpc = ISD::FLOG10; IsUnary = true; break; +  case ISD::STRICT_FLOG2: NewOpc = ISD::FLOG2; IsUnary = true; break; +  case ISD::STRICT_FRINT: NewOpc = ISD::FRINT; IsUnary = true; break; +  case ISD::STRICT_FNEARBYINT: +    NewOpc = ISD::FNEARBYINT; +    IsUnary = true; +    break; +  } + +  // We're taking this node out of the chain, so we need to re-link things. +  SDValue InputChain = Node->getOperand(0); +  SDValue OutputChain = SDValue(Node, 1); +  ReplaceAllUsesOfValueWith(OutputChain, InputChain); + +  SDVTList VTs = getVTList(Node->getOperand(1).getValueType()); +  SDNode *Res = nullptr; +  if (IsUnary) +    Res = MorphNodeTo(Node, NewOpc, VTs, { Node->getOperand(1) }); +  else +    Res = MorphNodeTo(Node, NewOpc, VTs, { Node->getOperand(1), +                                           Node->getOperand(2) }); +   +  // MorphNodeTo can operate in two ways: if an existing node with the +  // specified operands exists, it can just return it.  Otherwise, it +  // updates the node in place to have the requested operands. +  if (Res == Node) { +    // If we updated the node in place, reset the node ID.  To the isel, +    // this should be just like a newly allocated machine node. +    Res->setNodeId(-1); +  } else { +    ReplaceAllUsesWith(Node, Res); +    RemoveDeadNode(Node); +  } + +  return Res;  +} + +/// getMachineNode - These are used for target selectors to create a new node +/// with specified return type(s), MachineInstr opcode, and operands. +/// +/// Note that getMachineNode returns the resultant node.  If there is already a +/// node of the specified opcode and operands, it returns that node instead of +/// the current one. +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT) { +  SDVTList VTs = getVTList(VT); +  return getMachineNode(Opcode, dl, VTs, None); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT, SDValue Op1) { +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = { Op1 }; +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT, SDValue Op1, SDValue Op2) { +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = { Op1, Op2 }; +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT, SDValue Op1, SDValue Op2, +                                            SDValue Op3) { +  SDVTList VTs = getVTList(VT); +  SDValue Ops[] = { Op1, Op2, Op3 }; +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT, ArrayRef<SDValue> Ops) { +  SDVTList VTs = getVTList(VT); +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT1, EVT VT2, SDValue Op1, +                                            SDValue Op2) { +  SDVTList VTs = getVTList(VT1, VT2); +  SDValue Ops[] = { Op1, Op2 }; +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT1, EVT VT2, SDValue Op1, +                                            SDValue Op2, SDValue Op3) { +  SDVTList VTs = getVTList(VT1, VT2); +  SDValue Ops[] = { Op1, Op2, Op3 }; +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT1, EVT VT2, +                                            ArrayRef<SDValue> Ops) { +  SDVTList VTs = getVTList(VT1, VT2); +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT1, EVT VT2, EVT VT3, +                                            SDValue Op1, SDValue Op2) { +  SDVTList VTs = getVTList(VT1, VT2, VT3); +  SDValue Ops[] = { Op1, Op2 }; +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT1, EVT VT2, EVT VT3, +                                            SDValue Op1, SDValue Op2, +                                            SDValue Op3) { +  SDVTList VTs = getVTList(VT1, VT2, VT3); +  SDValue Ops[] = { Op1, Op2, Op3 }; +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            EVT VT1, EVT VT2, EVT VT3, +                                            ArrayRef<SDValue> Ops) { +  SDVTList VTs = getVTList(VT1, VT2, VT3); +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &dl, +                                            ArrayRef<EVT> ResultTys, +                                            ArrayRef<SDValue> Ops) { +  SDVTList VTs = getVTList(ResultTys); +  return getMachineNode(Opcode, dl, VTs, Ops); +} + +MachineSDNode *SelectionDAG::getMachineNode(unsigned Opcode, const SDLoc &DL, +                                            SDVTList VTs, +                                            ArrayRef<SDValue> Ops) { +  bool DoCSE = VTs.VTs[VTs.NumVTs-1] != MVT::Glue; +  MachineSDNode *N; +  void *IP = nullptr; + +  if (DoCSE) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, ~Opcode, VTs, Ops); +    IP = nullptr; +    if (SDNode *E = FindNodeOrInsertPos(ID, DL, IP)) { +      return cast<MachineSDNode>(UpdateSDLocOnMergeSDNode(E, DL)); +    } +  } + +  // Allocate a new MachineSDNode. +  N = newSDNode<MachineSDNode>(~Opcode, DL.getIROrder(), DL.getDebugLoc(), VTs); +  createOperands(N, Ops); + +  if (DoCSE) +    CSEMap.InsertNode(N, IP); + +  InsertNode(N); +  return N; +} + +/// getTargetExtractSubreg - A convenience function for creating +/// TargetOpcode::EXTRACT_SUBREG nodes. +SDValue SelectionDAG::getTargetExtractSubreg(int SRIdx, const SDLoc &DL, EVT VT, +                                             SDValue Operand) { +  SDValue SRIdxVal = getTargetConstant(SRIdx, DL, MVT::i32); +  SDNode *Subreg = getMachineNode(TargetOpcode::EXTRACT_SUBREG, DL, +                                  VT, Operand, SRIdxVal); +  return SDValue(Subreg, 0); +} + +/// getTargetInsertSubreg - A convenience function for creating +/// TargetOpcode::INSERT_SUBREG nodes. +SDValue SelectionDAG::getTargetInsertSubreg(int SRIdx, const SDLoc &DL, EVT VT, +                                            SDValue Operand, SDValue Subreg) { +  SDValue SRIdxVal = getTargetConstant(SRIdx, DL, MVT::i32); +  SDNode *Result = getMachineNode(TargetOpcode::INSERT_SUBREG, DL, +                                  VT, Operand, Subreg, SRIdxVal); +  return SDValue(Result, 0); +} + +/// getNodeIfExists - Get the specified node if it's already available, or +/// else return NULL. +SDNode *SelectionDAG::getNodeIfExists(unsigned Opcode, SDVTList VTList, +                                      ArrayRef<SDValue> Ops, +                                      const SDNodeFlags Flags) { +  if (VTList.VTs[VTList.NumVTs - 1] != MVT::Glue) { +    FoldingSetNodeID ID; +    AddNodeIDNode(ID, Opcode, VTList, Ops); +    void *IP = nullptr; +    if (SDNode *E = FindNodeOrInsertPos(ID, SDLoc(), IP)) { +      E->intersectFlagsWith(Flags); +      return E; +    } +  } +  return nullptr; +} + +/// getDbgValue - Creates a SDDbgValue node. +/// +/// SDNode +SDDbgValue *SelectionDAG::getDbgValue(MDNode *Var, MDNode *Expr, SDNode *N, +                                      unsigned R, bool IsIndirect, uint64_t Off, +                                      const DebugLoc &DL, unsigned O) { +  assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) && +         "Expected inlined-at fields to agree"); +  return new (DbgInfo->getAlloc()) +      SDDbgValue(Var, Expr, N, R, IsIndirect, Off, DL, O); +} + +/// Constant +SDDbgValue *SelectionDAG::getConstantDbgValue(MDNode *Var, MDNode *Expr, +                                              const Value *C, uint64_t Off, +                                              const DebugLoc &DL, unsigned O) { +  assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) && +         "Expected inlined-at fields to agree"); +  return new (DbgInfo->getAlloc()) SDDbgValue(Var, Expr, C, Off, DL, O); +} + +/// FrameIndex +SDDbgValue *SelectionDAG::getFrameIndexDbgValue(MDNode *Var, MDNode *Expr, +                                                unsigned FI, uint64_t Off, +                                                const DebugLoc &DL, +                                                unsigned O) { +  assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) && +         "Expected inlined-at fields to agree"); +  return new (DbgInfo->getAlloc()) SDDbgValue(Var, Expr, FI, Off, DL, O); +} + +namespace { + +/// RAUWUpdateListener - Helper for ReplaceAllUsesWith - When the node +/// pointed to by a use iterator is deleted, increment the use iterator +/// so that it doesn't dangle. +/// +class RAUWUpdateListener : public SelectionDAG::DAGUpdateListener { +  SDNode::use_iterator &UI; +  SDNode::use_iterator &UE; + +  void NodeDeleted(SDNode *N, SDNode *E) override { +    // Increment the iterator as needed. +    while (UI != UE && N == *UI) +      ++UI; +  } + +public: +  RAUWUpdateListener(SelectionDAG &d, +                     SDNode::use_iterator &ui, +                     SDNode::use_iterator &ue) +    : SelectionDAG::DAGUpdateListener(d), UI(ui), UE(ue) {} +}; + +} // end anonymous namespace + +/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead. +/// This can cause recursive merging of nodes in the DAG. +/// +/// This version assumes From has a single result value. +/// +void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To) { +  SDNode *From = FromN.getNode(); +  assert(From->getNumValues() == 1 && FromN.getResNo() == 0 && +         "Cannot replace with this method!"); +  assert(From != To.getNode() && "Cannot replace uses of with self"); + +  // Preserve Debug Values +  TransferDbgValues(FromN, To); + +  // Iterate over all the existing uses of From. New uses will be added +  // to the beginning of the use list, which we avoid visiting. +  // This specifically avoids visiting uses of From that arise while the +  // replacement is happening, because any such uses would be the result +  // of CSE: If an existing node looks like From after one of its operands +  // is replaced by To, we don't want to replace of all its users with To +  // too. See PR3018 for more info. +  SDNode::use_iterator UI = From->use_begin(), UE = From->use_end(); +  RAUWUpdateListener Listener(*this, UI, UE); +  while (UI != UE) { +    SDNode *User = *UI; + +    // This node is about to morph, remove its old self from the CSE maps. +    RemoveNodeFromCSEMaps(User); + +    // A user can appear in a use list multiple times, and when this +    // happens the uses are usually next to each other in the list. +    // To help reduce the number of CSE recomputations, process all +    // the uses of this user that we can find this way. +    do { +      SDUse &Use = UI.getUse(); +      ++UI; +      Use.set(To); +    } while (UI != UE && *UI == User); + +    // Now that we have modified User, add it back to the CSE maps.  If it +    // already exists there, recursively merge the results together. +    AddModifiedNodeToCSEMaps(User); +  } + +  // If we just RAUW'd the root, take note. +  if (FromN == getRoot()) +    setRoot(To); +} + +/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead. +/// This can cause recursive merging of nodes in the DAG. +/// +/// This version assumes that for each value of From, there is a +/// corresponding value in To in the same position with the same type. +/// +void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To) { +#ifndef NDEBUG +  for (unsigned i = 0, e = From->getNumValues(); i != e; ++i) +    assert((!From->hasAnyUseOfValue(i) || +            From->getValueType(i) == To->getValueType(i)) && +           "Cannot use this version of ReplaceAllUsesWith!"); +#endif + +  // Handle the trivial case. +  if (From == To) +    return; + +  // Preserve Debug Info. Only do this if there's a use. +  for (unsigned i = 0, e = From->getNumValues(); i != e; ++i) +    if (From->hasAnyUseOfValue(i)) { +      assert((i < To->getNumValues()) && "Invalid To location"); +      TransferDbgValues(SDValue(From, i), SDValue(To, i)); +    } + +  // Iterate over just the existing users of From. See the comments in +  // the ReplaceAllUsesWith above. +  SDNode::use_iterator UI = From->use_begin(), UE = From->use_end(); +  RAUWUpdateListener Listener(*this, UI, UE); +  while (UI != UE) { +    SDNode *User = *UI; + +    // This node is about to morph, remove its old self from the CSE maps. +    RemoveNodeFromCSEMaps(User); + +    // A user can appear in a use list multiple times, and when this +    // happens the uses are usually next to each other in the list. +    // To help reduce the number of CSE recomputations, process all +    // the uses of this user that we can find this way. +    do { +      SDUse &Use = UI.getUse(); +      ++UI; +      Use.setNode(To); +    } while (UI != UE && *UI == User); + +    // Now that we have modified User, add it back to the CSE maps.  If it +    // already exists there, recursively merge the results together. +    AddModifiedNodeToCSEMaps(User); +  } + +  // If we just RAUW'd the root, take note. +  if (From == getRoot().getNode()) +    setRoot(SDValue(To, getRoot().getResNo())); +} + +/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead. +/// This can cause recursive merging of nodes in the DAG. +/// +/// This version can replace From with any result values.  To must match the +/// number and types of values returned by From. +void SelectionDAG::ReplaceAllUsesWith(SDNode *From, const SDValue *To) { +  if (From->getNumValues() == 1)  // Handle the simple case efficiently. +    return ReplaceAllUsesWith(SDValue(From, 0), To[0]); + +  // Preserve Debug Info. +  for (unsigned i = 0, e = From->getNumValues(); i != e; ++i) +    TransferDbgValues(SDValue(From, i), *To); + +  // Iterate over just the existing users of From. See the comments in +  // the ReplaceAllUsesWith above. +  SDNode::use_iterator UI = From->use_begin(), UE = From->use_end(); +  RAUWUpdateListener Listener(*this, UI, UE); +  while (UI != UE) { +    SDNode *User = *UI; + +    // This node is about to morph, remove its old self from the CSE maps. +    RemoveNodeFromCSEMaps(User); + +    // A user can appear in a use list multiple times, and when this +    // happens the uses are usually next to each other in the list. +    // To help reduce the number of CSE recomputations, process all +    // the uses of this user that we can find this way. +    do { +      SDUse &Use = UI.getUse(); +      const SDValue &ToOp = To[Use.getResNo()]; +      ++UI; +      Use.set(ToOp); +    } while (UI != UE && *UI == User); + +    // Now that we have modified User, add it back to the CSE maps.  If it +    // already exists there, recursively merge the results together. +    AddModifiedNodeToCSEMaps(User); +  } + +  // If we just RAUW'd the root, take note. +  if (From == getRoot().getNode()) +    setRoot(SDValue(To[getRoot().getResNo()])); +} + +/// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving +/// uses of other values produced by From.getNode() alone.  The Deleted +/// vector is handled the same way as for ReplaceAllUsesWith. +void SelectionDAG::ReplaceAllUsesOfValueWith(SDValue From, SDValue To){ +  // Handle the really simple, really trivial case efficiently. +  if (From == To) return; + +  // Handle the simple, trivial, case efficiently. +  if (From.getNode()->getNumValues() == 1) { +    ReplaceAllUsesWith(From, To); +    return; +  } + +  // Preserve Debug Info. +  TransferDbgValues(From, To); + +  // Iterate over just the existing users of From. See the comments in +  // the ReplaceAllUsesWith above. +  SDNode::use_iterator UI = From.getNode()->use_begin(), +                       UE = From.getNode()->use_end(); +  RAUWUpdateListener Listener(*this, UI, UE); +  while (UI != UE) { +    SDNode *User = *UI; +    bool UserRemovedFromCSEMaps = false; + +    // A user can appear in a use list multiple times, and when this +    // happens the uses are usually next to each other in the list. +    // To help reduce the number of CSE recomputations, process all +    // the uses of this user that we can find this way. +    do { +      SDUse &Use = UI.getUse(); + +      // Skip uses of different values from the same node. +      if (Use.getResNo() != From.getResNo()) { +        ++UI; +        continue; +      } + +      // If this node hasn't been modified yet, it's still in the CSE maps, +      // so remove its old self from the CSE maps. +      if (!UserRemovedFromCSEMaps) { +        RemoveNodeFromCSEMaps(User); +        UserRemovedFromCSEMaps = true; +      } + +      ++UI; +      Use.set(To); +    } while (UI != UE && *UI == User); + +    // We are iterating over all uses of the From node, so if a use +    // doesn't use the specific value, no changes are made. +    if (!UserRemovedFromCSEMaps) +      continue; + +    // Now that we have modified User, add it back to the CSE maps.  If it +    // already exists there, recursively merge the results together. +    AddModifiedNodeToCSEMaps(User); +  } + +  // If we just RAUW'd the root, take note. +  if (From == getRoot()) +    setRoot(To); +} + +namespace { + +  /// UseMemo - This class is used by SelectionDAG::ReplaceAllUsesOfValuesWith +  /// to record information about a use. +  struct UseMemo { +    SDNode *User; +    unsigned Index; +    SDUse *Use; +  }; + +  /// operator< - Sort Memos by User. +  bool operator<(const UseMemo &L, const UseMemo &R) { +    return (intptr_t)L.User < (intptr_t)R.User; +  } + +} // end anonymous namespace + +/// ReplaceAllUsesOfValuesWith - Replace any uses of From with To, leaving +/// uses of other values produced by From.getNode() alone.  The same value +/// may appear in both the From and To list.  The Deleted vector is +/// handled the same way as for ReplaceAllUsesWith. +void SelectionDAG::ReplaceAllUsesOfValuesWith(const SDValue *From, +                                              const SDValue *To, +                                              unsigned Num){ +  // Handle the simple, trivial case efficiently. +  if (Num == 1) +    return ReplaceAllUsesOfValueWith(*From, *To); + +  TransferDbgValues(*From, *To); + +  // Read up all the uses and make records of them. This helps +  // processing new uses that are introduced during the +  // replacement process. +  SmallVector<UseMemo, 4> Uses; +  for (unsigned i = 0; i != Num; ++i) { +    unsigned FromResNo = From[i].getResNo(); +    SDNode *FromNode = From[i].getNode(); +    for (SDNode::use_iterator UI = FromNode->use_begin(), +         E = FromNode->use_end(); UI != E; ++UI) { +      SDUse &Use = UI.getUse(); +      if (Use.getResNo() == FromResNo) { +        UseMemo Memo = { *UI, i, &Use }; +        Uses.push_back(Memo); +      } +    } +  } + +  // Sort the uses, so that all the uses from a given User are together. +  std::sort(Uses.begin(), Uses.end()); + +  for (unsigned UseIndex = 0, UseIndexEnd = Uses.size(); +       UseIndex != UseIndexEnd; ) { +    // We know that this user uses some value of From.  If it is the right +    // value, update it. +    SDNode *User = Uses[UseIndex].User; + +    // This node is about to morph, remove its old self from the CSE maps. +    RemoveNodeFromCSEMaps(User); + +    // The Uses array is sorted, so all the uses for a given User +    // are next to each other in the list. +    // To help reduce the number of CSE recomputations, process all +    // the uses of this user that we can find this way. +    do { +      unsigned i = Uses[UseIndex].Index; +      SDUse &Use = *Uses[UseIndex].Use; +      ++UseIndex; + +      Use.set(To[i]); +    } while (UseIndex != UseIndexEnd && Uses[UseIndex].User == User); + +    // Now that we have modified User, add it back to the CSE maps.  If it +    // already exists there, recursively merge the results together. +    AddModifiedNodeToCSEMaps(User); +  } +} + +/// AssignTopologicalOrder - Assign a unique node id for each node in the DAG +/// based on their topological order. It returns the maximum id and a vector +/// of the SDNodes* in assigned order by reference. +unsigned SelectionDAG::AssignTopologicalOrder() { +  unsigned DAGSize = 0; + +  // SortedPos tracks the progress of the algorithm. Nodes before it are +  // sorted, nodes after it are unsorted. When the algorithm completes +  // it is at the end of the list. +  allnodes_iterator SortedPos = allnodes_begin(); + +  // Visit all the nodes. Move nodes with no operands to the front of +  // the list immediately. Annotate nodes that do have operands with their +  // operand count. Before we do this, the Node Id fields of the nodes +  // may contain arbitrary values. After, the Node Id fields for nodes +  // before SortedPos will contain the topological sort index, and the +  // Node Id fields for nodes At SortedPos and after will contain the +  // count of outstanding operands. +  for (allnodes_iterator I = allnodes_begin(),E = allnodes_end(); I != E; ) { +    SDNode *N = &*I++; +    checkForCycles(N, this); +    unsigned Degree = N->getNumOperands(); +    if (Degree == 0) { +      // A node with no uses, add it to the result array immediately. +      N->setNodeId(DAGSize++); +      allnodes_iterator Q(N); +      if (Q != SortedPos) +        SortedPos = AllNodes.insert(SortedPos, AllNodes.remove(Q)); +      assert(SortedPos != AllNodes.end() && "Overran node list"); +      ++SortedPos; +    } else { +      // Temporarily use the Node Id as scratch space for the degree count. +      N->setNodeId(Degree); +    } +  } + +  // Visit all the nodes. As we iterate, move nodes into sorted order, +  // such that by the time the end is reached all nodes will be sorted. +  for (SDNode &Node : allnodes()) { +    SDNode *N = &Node; +    checkForCycles(N, this); +    // N is in sorted position, so all its uses have one less operand +    // that needs to be sorted. +    for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end(); +         UI != UE; ++UI) { +      SDNode *P = *UI; +      unsigned Degree = P->getNodeId(); +      assert(Degree != 0 && "Invalid node degree"); +      --Degree; +      if (Degree == 0) { +        // All of P's operands are sorted, so P may sorted now. +        P->setNodeId(DAGSize++); +        if (P->getIterator() != SortedPos) +          SortedPos = AllNodes.insert(SortedPos, AllNodes.remove(P)); +        assert(SortedPos != AllNodes.end() && "Overran node list"); +        ++SortedPos; +      } else { +        // Update P's outstanding operand count. +        P->setNodeId(Degree); +      } +    } +    if (Node.getIterator() == SortedPos) { +#ifndef NDEBUG +      allnodes_iterator I(N); +      SDNode *S = &*++I; +      dbgs() << "Overran sorted position:\n"; +      S->dumprFull(this); dbgs() << "\n"; +      dbgs() << "Checking if this is due to cycles\n"; +      checkForCycles(this, true); +#endif +      llvm_unreachable(nullptr); +    } +  } + +  assert(SortedPos == AllNodes.end() && +         "Topological sort incomplete!"); +  assert(AllNodes.front().getOpcode() == ISD::EntryToken && +         "First node in topological sort is not the entry token!"); +  assert(AllNodes.front().getNodeId() == 0 && +         "First node in topological sort has non-zero id!"); +  assert(AllNodes.front().getNumOperands() == 0 && +         "First node in topological sort has operands!"); +  assert(AllNodes.back().getNodeId() == (int)DAGSize-1 && +         "Last node in topologic sort has unexpected id!"); +  assert(AllNodes.back().use_empty() && +         "Last node in topologic sort has users!"); +  assert(DAGSize == allnodes_size() && "Node count mismatch!"); +  return DAGSize; +} + +/// AddDbgValue - Add a dbg_value SDNode. If SD is non-null that means the +/// value is produced by SD. +void SelectionDAG::AddDbgValue(SDDbgValue *DB, SDNode *SD, bool isParameter) { +  if (SD) { +    assert(DbgInfo->getSDDbgValues(SD).empty() || SD->getHasDebugValue()); +    SD->setHasDebugValue(true); +  } +  DbgInfo->add(DB, SD, isParameter); +} + +/// TransferDbgValues - Transfer SDDbgValues. Called in replace nodes. +void SelectionDAG::TransferDbgValues(SDValue From, SDValue To) { +  if (From == To || !From.getNode()->getHasDebugValue()) +    return; +  SDNode *FromNode = From.getNode(); +  SDNode *ToNode = To.getNode(); +  ArrayRef<SDDbgValue *> DVs = GetDbgValues(FromNode); +  SmallVector<SDDbgValue *, 2> ClonedDVs; +  for (ArrayRef<SDDbgValue *>::iterator I = DVs.begin(), E = DVs.end(); +       I != E; ++I) { +    SDDbgValue *Dbg = *I; +    // Only add Dbgvalues attached to same ResNo. +    if (Dbg->getKind() == SDDbgValue::SDNODE && +        Dbg->getSDNode() == From.getNode() && +        Dbg->getResNo() == From.getResNo() && !Dbg->isInvalidated()) { +      assert(FromNode != ToNode && +             "Should not transfer Debug Values intranode"); +      SDDbgValue *Clone = +          getDbgValue(Dbg->getVariable(), Dbg->getExpression(), ToNode, +                      To.getResNo(), Dbg->isIndirect(), Dbg->getOffset(), +                      Dbg->getDebugLoc(), Dbg->getOrder()); +      ClonedDVs.push_back(Clone); +      Dbg->setIsInvalidated(); +    } +  } +  for (SDDbgValue *I : ClonedDVs) +    AddDbgValue(I, ToNode, false); +} + +//===----------------------------------------------------------------------===// +//                              SDNode Class +//===----------------------------------------------------------------------===// + +bool llvm::isNullConstant(SDValue V) { +  ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V); +  return Const != nullptr && Const->isNullValue(); +} + +bool llvm::isNullFPConstant(SDValue V) { +  ConstantFPSDNode *Const = dyn_cast<ConstantFPSDNode>(V); +  return Const != nullptr && Const->isZero() && !Const->isNegative(); +} + +bool llvm::isAllOnesConstant(SDValue V) { +  ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V); +  return Const != nullptr && Const->isAllOnesValue(); +} + +bool llvm::isOneConstant(SDValue V) { +  ConstantSDNode *Const = dyn_cast<ConstantSDNode>(V); +  return Const != nullptr && Const->isOne(); +} + +bool llvm::isBitwiseNot(SDValue V) { +  return V.getOpcode() == ISD::XOR && isAllOnesConstant(V.getOperand(1)); +} + +ConstantSDNode *llvm::isConstOrConstSplat(SDValue N) { +  if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N)) +    return CN; + +  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) { +    BitVector UndefElements; +    ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements); + +    // BuildVectors can truncate their operands. Ignore that case here. +    // FIXME: We blindly ignore splats which include undef which is overly +    // pessimistic. +    if (CN && UndefElements.none() && +        CN->getValueType(0) == N.getValueType().getScalarType()) +      return CN; +  } + +  return nullptr; +} + +ConstantFPSDNode *llvm::isConstOrConstSplatFP(SDValue N) { +  if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N)) +    return CN; + +  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) { +    BitVector UndefElements; +    ConstantFPSDNode *CN = BV->getConstantFPSplatNode(&UndefElements); + +    if (CN && UndefElements.none()) +      return CN; +  } + +  return nullptr; +} + +HandleSDNode::~HandleSDNode() { +  DropOperands(); +} + +GlobalAddressSDNode::GlobalAddressSDNode(unsigned Opc, unsigned Order, +                                         const DebugLoc &DL, +                                         const GlobalValue *GA, EVT VT, +                                         int64_t o, unsigned char TF) +    : SDNode(Opc, Order, DL, getSDVTList(VT)), Offset(o), TargetFlags(TF) { +  TheGlobal = GA; +} + +AddrSpaceCastSDNode::AddrSpaceCastSDNode(unsigned Order, const DebugLoc &dl, +                                         EVT VT, unsigned SrcAS, +                                         unsigned DestAS) +    : SDNode(ISD::ADDRSPACECAST, Order, dl, getSDVTList(VT)), +      SrcAddrSpace(SrcAS), DestAddrSpace(DestAS) {} + +MemSDNode::MemSDNode(unsigned Opc, unsigned Order, const DebugLoc &dl, +                     SDVTList VTs, EVT memvt, MachineMemOperand *mmo) +    : SDNode(Opc, Order, dl, VTs), MemoryVT(memvt), MMO(mmo) { +  MemSDNodeBits.IsVolatile = MMO->isVolatile(); +  MemSDNodeBits.IsNonTemporal = MMO->isNonTemporal(); +  MemSDNodeBits.IsDereferenceable = MMO->isDereferenceable(); +  MemSDNodeBits.IsInvariant = MMO->isInvariant(); + +  // We check here that the size of the memory operand fits within the size of +  // the MMO. This is because the MMO might indicate only a possible address +  // range instead of specifying the affected memory addresses precisely. +  assert(memvt.getStoreSize() <= MMO->getSize() && "Size mismatch!"); +} + +/// Profile - Gather unique data for the node. +/// +void SDNode::Profile(FoldingSetNodeID &ID) const { +  AddNodeIDNode(ID, this); +} + +namespace { + +  struct EVTArray { +    std::vector<EVT> VTs; + +    EVTArray() { +      VTs.reserve(MVT::LAST_VALUETYPE); +      for (unsigned i = 0; i < MVT::LAST_VALUETYPE; ++i) +        VTs.push_back(MVT((MVT::SimpleValueType)i)); +    } +  }; + +} // end anonymous namespace + +static ManagedStatic<std::set<EVT, EVT::compareRawBits>> EVTs; +static ManagedStatic<EVTArray> SimpleVTArray; +static ManagedStatic<sys::SmartMutex<true>> VTMutex; + +/// getValueTypeList - Return a pointer to the specified value type. +/// +const EVT *SDNode::getValueTypeList(EVT VT) { +  if (VT.isExtended()) { +    sys::SmartScopedLock<true> Lock(*VTMutex); +    return &(*EVTs->insert(VT).first); +  } else { +    assert(VT.getSimpleVT() < MVT::LAST_VALUETYPE && +           "Value type out of range!"); +    return &SimpleVTArray->VTs[VT.getSimpleVT().SimpleTy]; +  } +} + +/// hasNUsesOfValue - Return true if there are exactly NUSES uses of the +/// indicated value.  This method ignores uses of other values defined by this +/// operation. +bool SDNode::hasNUsesOfValue(unsigned NUses, unsigned Value) const { +  assert(Value < getNumValues() && "Bad value!"); + +  // TODO: Only iterate over uses of a given value of the node +  for (SDNode::use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) { +    if (UI.getUse().getResNo() == Value) { +      if (NUses == 0) +        return false; +      --NUses; +    } +  } + +  // Found exactly the right number of uses? +  return NUses == 0; +} + +/// hasAnyUseOfValue - Return true if there are any use of the indicated +/// value. This method ignores uses of other values defined by this operation. +bool SDNode::hasAnyUseOfValue(unsigned Value) const { +  assert(Value < getNumValues() && "Bad value!"); + +  for (SDNode::use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) +    if (UI.getUse().getResNo() == Value) +      return true; + +  return false; +} + +/// isOnlyUserOf - Return true if this node is the only use of N. +bool SDNode::isOnlyUserOf(const SDNode *N) const { +  bool Seen = false; +  for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) { +    SDNode *User = *I; +    if (User == this) +      Seen = true; +    else +      return false; +  } + +  return Seen; +} + +/// Return true if the only users of N are contained in Nodes. +bool SDNode::areOnlyUsersOf(ArrayRef<const SDNode *> Nodes, const SDNode *N) { +  bool Seen = false; +  for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) { +    SDNode *User = *I; +    if (llvm::any_of(Nodes, +                     [&User](const SDNode *Node) { return User == Node; })) +      Seen = true; +    else +      return false; +  } + +  return Seen; +} + +/// isOperand - Return true if this node is an operand of N. +bool SDValue::isOperandOf(const SDNode *N) const { +  for (const SDValue &Op : N->op_values()) +    if (*this == Op) +      return true; +  return false; +} + +bool SDNode::isOperandOf(const SDNode *N) const { +  for (const SDValue &Op : N->op_values()) +    if (this == Op.getNode()) +      return true; +  return false; +} + +/// reachesChainWithoutSideEffects - Return true if this operand (which must +/// be a chain) reaches the specified operand without crossing any +/// side-effecting instructions on any chain path.  In practice, this looks +/// through token factors and non-volatile loads.  In order to remain efficient, +/// this only looks a couple of nodes in, it does not do an exhaustive search. +/// +/// Note that we only need to examine chains when we're searching for +/// side-effects; SelectionDAG requires that all side-effects are represented +/// by chains, even if another operand would force a specific ordering. This +/// constraint is necessary to allow transformations like splitting loads. +bool SDValue::reachesChainWithoutSideEffects(SDValue Dest, +                                             unsigned Depth) const { +  if (*this == Dest) return true; + +  // Don't search too deeply, we just want to be able to see through +  // TokenFactor's etc. +  if (Depth == 0) return false; + +  // If this is a token factor, all inputs to the TF happen in parallel. +  if (getOpcode() == ISD::TokenFactor) { +    // First, try a shallow search. +    if (is_contained((*this)->ops(), Dest)) { +      // We found the chain we want as an operand of this TokenFactor. +      // Essentially, we reach the chain without side-effects if we could +      // serialize the TokenFactor into a simple chain of operations with +      // Dest as the last operation. This is automatically true if the +      // chain has one use: there are no other ordering constraints. +      // If the chain has more than one use, we give up: some other +      // use of Dest might force a side-effect between Dest and the current +      // node. +      if (Dest.hasOneUse()) +        return true; +    } +    // Next, try a deep search: check whether every operand of the TokenFactor +    // reaches Dest. +    return llvm::all_of((*this)->ops(), [=](SDValue Op) { +      return Op.reachesChainWithoutSideEffects(Dest, Depth - 1); +    }); +  } + +  // Loads don't have side effects, look through them. +  if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(*this)) { +    if (!Ld->isVolatile()) +      return Ld->getChain().reachesChainWithoutSideEffects(Dest, Depth-1); +  } +  return false; +} + +bool SDNode::hasPredecessor(const SDNode *N) const { +  SmallPtrSet<const SDNode *, 32> Visited; +  SmallVector<const SDNode *, 16> Worklist; +  Worklist.push_back(this); +  return hasPredecessorHelper(N, Visited, Worklist); +} + +void SDNode::intersectFlagsWith(const SDNodeFlags Flags) { +  this->Flags.intersectWith(Flags); +} + +SDValue SelectionDAG::UnrollVectorOp(SDNode *N, unsigned ResNE) { +  assert(N->getNumValues() == 1 && +         "Can't unroll a vector with multiple results!"); + +  EVT VT = N->getValueType(0); +  unsigned NE = VT.getVectorNumElements(); +  EVT EltVT = VT.getVectorElementType(); +  SDLoc dl(N); + +  SmallVector<SDValue, 8> Scalars; +  SmallVector<SDValue, 4> Operands(N->getNumOperands()); + +  // If ResNE is 0, fully unroll the vector op. +  if (ResNE == 0) +    ResNE = NE; +  else if (NE > ResNE) +    NE = ResNE; + +  unsigned i; +  for (i= 0; i != NE; ++i) { +    for (unsigned j = 0, e = N->getNumOperands(); j != e; ++j) { +      SDValue Operand = N->getOperand(j); +      EVT OperandVT = Operand.getValueType(); +      if (OperandVT.isVector()) { +        // A vector operand; extract a single element. +        EVT OperandEltVT = OperandVT.getVectorElementType(); +        Operands[j] = +            getNode(ISD::EXTRACT_VECTOR_ELT, dl, OperandEltVT, Operand, +                    getConstant(i, dl, TLI->getVectorIdxTy(getDataLayout()))); +      } else { +        // A scalar operand; just use it as is. +        Operands[j] = Operand; +      } +    } + +    switch (N->getOpcode()) { +    default: { +      Scalars.push_back(getNode(N->getOpcode(), dl, EltVT, Operands, +                                N->getFlags())); +      break; +    } +    case ISD::VSELECT: +      Scalars.push_back(getNode(ISD::SELECT, dl, EltVT, Operands)); +      break; +    case ISD::SHL: +    case ISD::SRA: +    case ISD::SRL: +    case ISD::ROTL: +    case ISD::ROTR: +      Scalars.push_back(getNode(N->getOpcode(), dl, EltVT, Operands[0], +                               getShiftAmountOperand(Operands[0].getValueType(), +                                                     Operands[1]))); +      break; +    case ISD::SIGN_EXTEND_INREG: +    case ISD::FP_ROUND_INREG: { +      EVT ExtVT = cast<VTSDNode>(Operands[1])->getVT().getVectorElementType(); +      Scalars.push_back(getNode(N->getOpcode(), dl, EltVT, +                                Operands[0], +                                getValueType(ExtVT))); +    } +    } +  } + +  for (; i < ResNE; ++i) +    Scalars.push_back(getUNDEF(EltVT)); + +  EVT VecVT = EVT::getVectorVT(*getContext(), EltVT, ResNE); +  return getBuildVector(VecVT, dl, Scalars); +} + +bool SelectionDAG::areNonVolatileConsecutiveLoads(LoadSDNode *LD, +                                                  LoadSDNode *Base, +                                                  unsigned Bytes, +                                                  int Dist) const { +  if (LD->isVolatile() || Base->isVolatile()) +    return false; +  if (LD->isIndexed() || Base->isIndexed()) +    return false; +  if (LD->getChain() != Base->getChain()) +    return false; +  EVT VT = LD->getValueType(0); +  if (VT.getSizeInBits() / 8 != Bytes) +    return false; + +  SDValue Loc = LD->getOperand(1); +  SDValue BaseLoc = Base->getOperand(1); +  if (Loc.getOpcode() == ISD::FrameIndex) { +    if (BaseLoc.getOpcode() != ISD::FrameIndex) +      return false; +    const MachineFrameInfo &MFI = getMachineFunction().getFrameInfo(); +    int FI  = cast<FrameIndexSDNode>(Loc)->getIndex(); +    int BFI = cast<FrameIndexSDNode>(BaseLoc)->getIndex(); +    int FS  = MFI.getObjectSize(FI); +    int BFS = MFI.getObjectSize(BFI); +    if (FS != BFS || FS != (int)Bytes) return false; +    return MFI.getObjectOffset(FI) == (MFI.getObjectOffset(BFI) + Dist*Bytes); +  } + +  // Handle X + C. +  if (isBaseWithConstantOffset(Loc)) { +    int64_t LocOffset = cast<ConstantSDNode>(Loc.getOperand(1))->getSExtValue(); +    if (Loc.getOperand(0) == BaseLoc) { +      // If the base location is a simple address with no offset itself, then +      // the second load's first add operand should be the base address. +      if (LocOffset == Dist * (int)Bytes) +        return true; +    } else if (isBaseWithConstantOffset(BaseLoc)) { +      // The base location itself has an offset, so subtract that value from the +      // second load's offset before comparing to distance * size. +      int64_t BOffset = +        cast<ConstantSDNode>(BaseLoc.getOperand(1))->getSExtValue(); +      if (Loc.getOperand(0) == BaseLoc.getOperand(0)) { +        if ((LocOffset - BOffset) == Dist * (int)Bytes) +          return true; +      } +    } +  } +  const GlobalValue *GV1 = nullptr; +  const GlobalValue *GV2 = nullptr; +  int64_t Offset1 = 0; +  int64_t Offset2 = 0; +  bool isGA1 = TLI->isGAPlusOffset(Loc.getNode(), GV1, Offset1); +  bool isGA2 = TLI->isGAPlusOffset(BaseLoc.getNode(), GV2, Offset2); +  if (isGA1 && isGA2 && GV1 == GV2) +    return Offset1 == (Offset2 + Dist*Bytes); +  return false; +} + +/// InferPtrAlignment - Infer alignment of a load / store address. Return 0 if +/// it cannot be inferred. +unsigned SelectionDAG::InferPtrAlignment(SDValue Ptr) const { +  // If this is a GlobalAddress + cst, return the alignment. +  const GlobalValue *GV; +  int64_t GVOffset = 0; +  if (TLI->isGAPlusOffset(Ptr.getNode(), GV, GVOffset)) { +    unsigned PtrWidth = getDataLayout().getPointerTypeSizeInBits(GV->getType()); +    KnownBits Known(PtrWidth); +    llvm::computeKnownBits(GV, Known, getDataLayout()); +    unsigned AlignBits = Known.countMinTrailingZeros(); +    unsigned Align = AlignBits ? 1 << std::min(31U, AlignBits) : 0; +    if (Align) +      return MinAlign(Align, GVOffset); +  } + +  // If this is a direct reference to a stack slot, use information about the +  // stack slot's alignment. +  int FrameIdx = 1 << 31; +  int64_t FrameOffset = 0; +  if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Ptr)) { +    FrameIdx = FI->getIndex(); +  } else if (isBaseWithConstantOffset(Ptr) && +             isa<FrameIndexSDNode>(Ptr.getOperand(0))) { +    // Handle FI+Cst +    FrameIdx = cast<FrameIndexSDNode>(Ptr.getOperand(0))->getIndex(); +    FrameOffset = Ptr.getConstantOperandVal(1); +  } + +  if (FrameIdx != (1 << 31)) { +    const MachineFrameInfo &MFI = getMachineFunction().getFrameInfo(); +    unsigned FIInfoAlign = MinAlign(MFI.getObjectAlignment(FrameIdx), +                                    FrameOffset); +    return FIInfoAlign; +  } + +  return 0; +} + +/// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type +/// which is split (or expanded) into two not necessarily identical pieces. +std::pair<EVT, EVT> SelectionDAG::GetSplitDestVTs(const EVT &VT) const { +  // Currently all types are split in half. +  EVT LoVT, HiVT; +  if (!VT.isVector()) +    LoVT = HiVT = TLI->getTypeToTransformTo(*getContext(), VT); +  else +    LoVT = HiVT = VT.getHalfNumVectorElementsVT(*getContext()); + +  return std::make_pair(LoVT, HiVT); +} + +/// SplitVector - Split the vector with EXTRACT_SUBVECTOR and return the +/// low/high part. +std::pair<SDValue, SDValue> +SelectionDAG::SplitVector(const SDValue &N, const SDLoc &DL, const EVT &LoVT, +                          const EVT &HiVT) { +  assert(LoVT.getVectorNumElements() + HiVT.getVectorNumElements() <= +         N.getValueType().getVectorNumElements() && +         "More vector elements requested than available!"); +  SDValue Lo, Hi; +  Lo = getNode(ISD::EXTRACT_SUBVECTOR, DL, LoVT, N, +               getConstant(0, DL, TLI->getVectorIdxTy(getDataLayout()))); +  Hi = getNode(ISD::EXTRACT_SUBVECTOR, DL, HiVT, N, +               getConstant(LoVT.getVectorNumElements(), DL, +                           TLI->getVectorIdxTy(getDataLayout()))); +  return std::make_pair(Lo, Hi); +} + +void SelectionDAG::ExtractVectorElements(SDValue Op, +                                         SmallVectorImpl<SDValue> &Args, +                                         unsigned Start, unsigned Count) { +  EVT VT = Op.getValueType(); +  if (Count == 0) +    Count = VT.getVectorNumElements(); + +  EVT EltVT = VT.getVectorElementType(); +  EVT IdxTy = TLI->getVectorIdxTy(getDataLayout()); +  SDLoc SL(Op); +  for (unsigned i = Start, e = Start + Count; i != e; ++i) { +    Args.push_back(getNode(ISD::EXTRACT_VECTOR_ELT, SL, EltVT, +                           Op, getConstant(i, SL, IdxTy))); +  } +} + +// getAddressSpace - Return the address space this GlobalAddress belongs to. +unsigned GlobalAddressSDNode::getAddressSpace() const { +  return getGlobal()->getType()->getAddressSpace(); +} + +Type *ConstantPoolSDNode::getType() const { +  if (isMachineConstantPoolEntry()) +    return Val.MachineCPVal->getType(); +  return Val.ConstVal->getType(); +} + +bool BuildVectorSDNode::isConstantSplat(APInt &SplatValue, APInt &SplatUndef, +                                        unsigned &SplatBitSize, +                                        bool &HasAnyUndefs, +                                        unsigned MinSplatBits, +                                        bool IsBigEndian) const { +  EVT VT = getValueType(0); +  assert(VT.isVector() && "Expected a vector type"); +  unsigned VecWidth = VT.getSizeInBits(); +  if (MinSplatBits > VecWidth) +    return false; + +  // FIXME: The widths are based on this node's type, but build vectors can +  // truncate their operands. +  SplatValue = APInt(VecWidth, 0); +  SplatUndef = APInt(VecWidth, 0); + +  // Get the bits. Bits with undefined values (when the corresponding element +  // of the vector is an ISD::UNDEF value) are set in SplatUndef and cleared +  // in SplatValue. If any of the values are not constant, give up and return +  // false. +  unsigned int NumOps = getNumOperands(); +  assert(NumOps > 0 && "isConstantSplat has 0-size build vector"); +  unsigned EltWidth = VT.getScalarSizeInBits(); + +  for (unsigned j = 0; j < NumOps; ++j) { +    unsigned i = IsBigEndian ? NumOps - 1 - j : j; +    SDValue OpVal = getOperand(i); +    unsigned BitPos = j * EltWidth; + +    if (OpVal.isUndef()) +      SplatUndef.setBits(BitPos, BitPos + EltWidth); +    else if (auto *CN = dyn_cast<ConstantSDNode>(OpVal)) +      SplatValue.insertBits(CN->getAPIntValue().zextOrTrunc(EltWidth), BitPos); +    else if (auto *CN = dyn_cast<ConstantFPSDNode>(OpVal)) +      SplatValue.insertBits(CN->getValueAPF().bitcastToAPInt(), BitPos); +    else +      return false; +  } + +  // The build_vector is all constants or undefs. Find the smallest element +  // size that splats the vector. +  HasAnyUndefs = (SplatUndef != 0); + +  // FIXME: This does not work for vectors with elements less than 8 bits. +  while (VecWidth > 8) { +    unsigned HalfSize = VecWidth / 2; +    APInt HighValue = SplatValue.lshr(HalfSize).trunc(HalfSize); +    APInt LowValue = SplatValue.trunc(HalfSize); +    APInt HighUndef = SplatUndef.lshr(HalfSize).trunc(HalfSize); +    APInt LowUndef = SplatUndef.trunc(HalfSize); + +    // If the two halves do not match (ignoring undef bits), stop here. +    if ((HighValue & ~LowUndef) != (LowValue & ~HighUndef) || +        MinSplatBits > HalfSize) +      break; + +    SplatValue = HighValue | LowValue; +    SplatUndef = HighUndef & LowUndef; + +    VecWidth = HalfSize; +  } + +  SplatBitSize = VecWidth; +  return true; +} + +SDValue BuildVectorSDNode::getSplatValue(BitVector *UndefElements) const { +  if (UndefElements) { +    UndefElements->clear(); +    UndefElements->resize(getNumOperands()); +  } +  SDValue Splatted; +  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { +    SDValue Op = getOperand(i); +    if (Op.isUndef()) { +      if (UndefElements) +        (*UndefElements)[i] = true; +    } else if (!Splatted) { +      Splatted = Op; +    } else if (Splatted != Op) { +      return SDValue(); +    } +  } + +  if (!Splatted) { +    assert(getOperand(0).isUndef() && +           "Can only have a splat without a constant for all undefs."); +    return getOperand(0); +  } + +  return Splatted; +} + +ConstantSDNode * +BuildVectorSDNode::getConstantSplatNode(BitVector *UndefElements) const { +  return dyn_cast_or_null<ConstantSDNode>(getSplatValue(UndefElements)); +} + +ConstantFPSDNode * +BuildVectorSDNode::getConstantFPSplatNode(BitVector *UndefElements) const { +  return dyn_cast_or_null<ConstantFPSDNode>(getSplatValue(UndefElements)); +} + +int32_t +BuildVectorSDNode::getConstantFPSplatPow2ToLog2Int(BitVector *UndefElements, +                                                   uint32_t BitWidth) const { +  if (ConstantFPSDNode *CN = +          dyn_cast_or_null<ConstantFPSDNode>(getSplatValue(UndefElements))) { +    bool IsExact; +    APSInt IntVal(BitWidth); +    const APFloat &APF = CN->getValueAPF(); +    if (APF.convertToInteger(IntVal, APFloat::rmTowardZero, &IsExact) != +            APFloat::opOK || +        !IsExact) +      return -1; + +    return IntVal.exactLogBase2(); +  } +  return -1; +} + +bool BuildVectorSDNode::isConstant() const { +  for (const SDValue &Op : op_values()) { +    unsigned Opc = Op.getOpcode(); +    if (Opc != ISD::UNDEF && Opc != ISD::Constant && Opc != ISD::ConstantFP) +      return false; +  } +  return true; +} + +bool ShuffleVectorSDNode::isSplatMask(const int *Mask, EVT VT) { +  // Find the first non-undef value in the shuffle mask. +  unsigned i, e; +  for (i = 0, e = VT.getVectorNumElements(); i != e && Mask[i] < 0; ++i) +    /* search */; + +  assert(i != e && "VECTOR_SHUFFLE node with all undef indices!"); + +  // Make sure all remaining elements are either undef or the same as the first +  // non-undef value. +  for (int Idx = Mask[i]; i != e; ++i) +    if (Mask[i] >= 0 && Mask[i] != Idx) +      return false; +  return true; +} + +// \brief Returns the SDNode if it is a constant integer BuildVector +// or constant integer. +SDNode *SelectionDAG::isConstantIntBuildVectorOrConstantInt(SDValue N) { +  if (isa<ConstantSDNode>(N)) +    return N.getNode(); +  if (ISD::isBuildVectorOfConstantSDNodes(N.getNode())) +    return N.getNode(); +  // Treat a GlobalAddress supporting constant offset folding as a +  // constant integer. +  if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N)) +    if (GA->getOpcode() == ISD::GlobalAddress && +        TLI->isOffsetFoldingLegal(GA)) +      return GA; +  return nullptr; +} + +SDNode *SelectionDAG::isConstantFPBuildVectorOrConstantFP(SDValue N) { +  if (isa<ConstantFPSDNode>(N)) +    return N.getNode(); + +  if (ISD::isBuildVectorOfConstantFPSDNodes(N.getNode())) +    return N.getNode(); + +  return nullptr; +} + +#ifndef NDEBUG +static void checkForCyclesHelper(const SDNode *N, +                                 SmallPtrSetImpl<const SDNode*> &Visited, +                                 SmallPtrSetImpl<const SDNode*> &Checked, +                                 const llvm::SelectionDAG *DAG) { +  // If this node has already been checked, don't check it again. +  if (Checked.count(N)) +    return; + +  // If a node has already been visited on this depth-first walk, reject it as +  // a cycle. +  if (!Visited.insert(N).second) { +    errs() << "Detected cycle in SelectionDAG\n"; +    dbgs() << "Offending node:\n"; +    N->dumprFull(DAG); dbgs() << "\n"; +    abort(); +  } + +  for (const SDValue &Op : N->op_values()) +    checkForCyclesHelper(Op.getNode(), Visited, Checked, DAG); + +  Checked.insert(N); +  Visited.erase(N); +} +#endif + +void llvm::checkForCycles(const llvm::SDNode *N, +                          const llvm::SelectionDAG *DAG, +                          bool force) { +#ifndef NDEBUG +  bool check = force; +#ifdef EXPENSIVE_CHECKS +  check = true; +#endif  // EXPENSIVE_CHECKS +  if (check) { +    assert(N && "Checking nonexistent SDNode"); +    SmallPtrSet<const SDNode*, 32> visited; +    SmallPtrSet<const SDNode*, 32> checked; +    checkForCyclesHelper(N, visited, checked, DAG); +  } +#endif  // !NDEBUG +} + +void llvm::checkForCycles(const llvm::SelectionDAG *DAG, bool force) { +  checkForCycles(DAG->getRoot().getNode(), DAG, force); +}  | 
