| //===-- LegalizeDAG.cpp - Implement SelectionDAG::Legalize ----------------===// | 
 | // | 
 | //                     The LLVM Compiler Infrastructure | 
 | // | 
 | // This file was developed by the LLVM research group and is distributed under | 
 | // the University of Illinois Open Source License. See LICENSE.TXT for details. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 | // | 
 | // This file implements the SelectionDAG::Legalize method. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | #include "llvm/CodeGen/SelectionDAG.h" | 
 | #include "llvm/CodeGen/MachineConstantPool.h" | 
 | #include "llvm/CodeGen/MachineFunction.h" | 
 | #include "llvm/CodeGen/MachineFrameInfo.h" | 
 | #include "llvm/Target/TargetLowering.h" | 
 | #include "llvm/Target/TargetData.h" | 
 | #include "llvm/Target/TargetOptions.h" | 
 | #include "llvm/Constants.h" | 
 | #include <iostream> | 
 | using namespace llvm; | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | /// SelectionDAGLegalize - This takes an arbitrary SelectionDAG as input and | 
 | /// hacks on it until the target machine can handle it.  This involves | 
 | /// eliminating value sizes the machine cannot handle (promoting small sizes to | 
 | /// large sizes or splitting up large values into small values) as well as | 
 | /// eliminating operations the machine cannot handle. | 
 | /// | 
 | /// This code also does a small amount of optimization and recognition of idioms | 
 | /// as part of its processing.  For example, if a target does not support a | 
 | /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this | 
 | /// will attempt merge setcc and brc instructions into brcc's. | 
 | /// | 
 | namespace { | 
 | class SelectionDAGLegalize { | 
 |   TargetLowering &TLI; | 
 |   SelectionDAG &DAG; | 
 |  | 
 |   /// LegalizeAction - This enum indicates what action we should take for each | 
 |   /// value type the can occur in the program. | 
 |   enum LegalizeAction { | 
 |     Legal,            // The target natively supports this value type. | 
 |     Promote,          // This should be promoted to the next larger type. | 
 |     Expand,           // This integer type should be broken into smaller pieces. | 
 |   }; | 
 |  | 
 |   /// ValueTypeActions - This is a bitvector that contains two bits for each | 
 |   /// value type, where the two bits correspond to the LegalizeAction enum. | 
 |   /// This can be queried with "getTypeAction(VT)". | 
 |   unsigned ValueTypeActions; | 
 |  | 
 |   /// NeedsAnotherIteration - This is set when we expand a large integer | 
 |   /// operation into smaller integer operations, but the smaller operations are | 
 |   /// not set.  This occurs only rarely in practice, for targets that don't have | 
 |   /// 32-bit or larger integer registers. | 
 |   bool NeedsAnotherIteration; | 
 |  | 
 |   /// LegalizedNodes - For nodes that are of legal width, and that have more | 
 |   /// than one use, this map indicates what regularized operand to use.  This | 
 |   /// allows us to avoid legalizing the same thing more than once. | 
 |   std::map<SDOperand, SDOperand> LegalizedNodes; | 
 |  | 
 |   /// PromotedNodes - For nodes that are below legal width, and that have more | 
 |   /// than one use, this map indicates what promoted value to use.  This allows | 
 |   /// us to avoid promoting the same thing more than once. | 
 |   std::map<SDOperand, SDOperand> PromotedNodes; | 
 |  | 
 |   /// ExpandedNodes - For nodes that need to be expanded, and which have more | 
 |   /// than one use, this map indicates which which operands are the expanded | 
 |   /// version of the input.  This allows us to avoid expanding the same node | 
 |   /// more than once. | 
 |   std::map<SDOperand, std::pair<SDOperand, SDOperand> > ExpandedNodes; | 
 |  | 
 |   void AddLegalizedOperand(SDOperand From, SDOperand To) { | 
 |     bool isNew = LegalizedNodes.insert(std::make_pair(From, To)).second; | 
 |     assert(isNew && "Got into the map somehow?"); | 
 |   } | 
 |   void AddPromotedOperand(SDOperand From, SDOperand To) { | 
 |     bool isNew = PromotedNodes.insert(std::make_pair(From, To)).second; | 
 |     assert(isNew && "Got into the map somehow?"); | 
 |   } | 
 |  | 
 | public: | 
 |  | 
 |   SelectionDAGLegalize(SelectionDAG &DAG); | 
 |  | 
 |   /// Run - While there is still lowering to do, perform a pass over the DAG. | 
 |   /// Most regularization can be done in a single pass, but targets that require | 
 |   /// large values to be split into registers multiple times (e.g. i64 -> 4x | 
 |   /// i16) require iteration for these values (the first iteration will demote | 
 |   /// to i32, the second will demote to i16). | 
 |   void Run() { | 
 |     do { | 
 |       NeedsAnotherIteration = false; | 
 |       LegalizeDAG(); | 
 |     } while (NeedsAnotherIteration); | 
 |   } | 
 |  | 
 |   /// getTypeAction - Return how we should legalize values of this type, either | 
 |   /// it is already legal or we need to expand it into multiple registers of | 
 |   /// smaller integer type, or we need to promote it to a larger type. | 
 |   LegalizeAction getTypeAction(MVT::ValueType VT) const { | 
 |     return (LegalizeAction)((ValueTypeActions >> (2*VT)) & 3); | 
 |   } | 
 |  | 
 |   /// isTypeLegal - Return true if this type is legal on this target. | 
 |   /// | 
 |   bool isTypeLegal(MVT::ValueType VT) const { | 
 |     return getTypeAction(VT) == Legal; | 
 |   } | 
 |  | 
 | private: | 
 |   void LegalizeDAG(); | 
 |  | 
 |   SDOperand LegalizeOp(SDOperand O); | 
 |   void ExpandOp(SDOperand O, SDOperand &Lo, SDOperand &Hi); | 
 |   SDOperand PromoteOp(SDOperand O); | 
 |  | 
 |   SDOperand ExpandLibCall(const char *Name, SDNode *Node, | 
 |                           SDOperand &Hi); | 
 |   SDOperand ExpandIntToFP(bool isSigned, MVT::ValueType DestTy, | 
 |                           SDOperand Source); | 
 |   bool ExpandShift(unsigned Opc, SDOperand Op, SDOperand Amt, | 
 |                    SDOperand &Lo, SDOperand &Hi); | 
 |   void ExpandShiftParts(unsigned NodeOp, SDOperand Op, SDOperand Amt, | 
 |                         SDOperand &Lo, SDOperand &Hi); | 
 |   void ExpandByParts(unsigned NodeOp, SDOperand LHS, SDOperand RHS, | 
 |                      SDOperand &Lo, SDOperand &Hi); | 
 |  | 
 |   void SpliceCallInto(const SDOperand &CallResult, SDNode *OutChain); | 
 |  | 
 |   SDOperand getIntPtrConstant(uint64_t Val) { | 
 |     return DAG.getConstant(Val, TLI.getPointerTy()); | 
 |   } | 
 | }; | 
 | } | 
 |  | 
 |  | 
 | SelectionDAGLegalize::SelectionDAGLegalize(SelectionDAG &dag) | 
 |   : TLI(dag.getTargetLoweringInfo()), DAG(dag), | 
 |     ValueTypeActions(TLI.getValueTypeActions()) { | 
 |   assert(MVT::LAST_VALUETYPE <= 16 && | 
 |          "Too many value types for ValueTypeActions to hold!"); | 
 | } | 
 |  | 
 | void SelectionDAGLegalize::LegalizeDAG() { | 
 |   SDOperand OldRoot = DAG.getRoot(); | 
 |   SDOperand NewRoot = LegalizeOp(OldRoot); | 
 |   DAG.setRoot(NewRoot); | 
 |  | 
 |   ExpandedNodes.clear(); | 
 |   LegalizedNodes.clear(); | 
 |   PromotedNodes.clear(); | 
 |  | 
 |   // Remove dead nodes now. | 
 |   DAG.RemoveDeadNodes(OldRoot.Val); | 
 | } | 
 |  | 
 | SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) { | 
 |   assert(getTypeAction(Op.getValueType()) == Legal && | 
 |          "Caller should expand or promote operands that are not legal!"); | 
 |   SDNode *Node = Op.Val; | 
 |  | 
 |   // If this operation defines any values that cannot be represented in a | 
 |   // register on this target, make sure to expand or promote them. | 
 |   if (Node->getNumValues() > 1) { | 
 |     for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) | 
 |       switch (getTypeAction(Node->getValueType(i))) { | 
 |       case Legal: break;  // Nothing to do. | 
 |       case Expand: { | 
 |         SDOperand T1, T2; | 
 |         ExpandOp(Op.getValue(i), T1, T2); | 
 |         assert(LegalizedNodes.count(Op) && | 
 |                "Expansion didn't add legal operands!"); | 
 |         return LegalizedNodes[Op]; | 
 |       } | 
 |       case Promote: | 
 |         PromoteOp(Op.getValue(i)); | 
 |         assert(LegalizedNodes.count(Op) && | 
 |                "Expansion didn't add legal operands!"); | 
 |         return LegalizedNodes[Op]; | 
 |       } | 
 |   } | 
 |  | 
 |   // Note that LegalizeOp may be reentered even from single-use nodes, which | 
 |   // means that we always must cache transformed nodes. | 
 |   std::map<SDOperand, SDOperand>::iterator I = LegalizedNodes.find(Op); | 
 |   if (I != LegalizedNodes.end()) return I->second; | 
 |  | 
 |   SDOperand Tmp1, Tmp2, Tmp3; | 
 |  | 
 |   SDOperand Result = Op; | 
 |  | 
 |   switch (Node->getOpcode()) { | 
 |   default: | 
 |     std::cerr << "NODE: "; Node->dump(); std::cerr << "\n"; | 
 |     assert(0 && "Do not know how to legalize this operator!"); | 
 |     abort(); | 
 |   case ISD::EntryToken: | 
 |   case ISD::FrameIndex: | 
 |   case ISD::GlobalAddress: | 
 |   case ISD::ExternalSymbol: | 
 |   case ISD::ConstantPool:           // Nothing to do. | 
 |     assert(getTypeAction(Node->getValueType(0)) == Legal && | 
 |            "This must be legal!"); | 
 |     break; | 
 |   case ISD::CopyFromReg: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     if (Tmp1 != Node->getOperand(0)) | 
 |       Result = DAG.getCopyFromReg(cast<RegSDNode>(Node)->getReg(), | 
 |                                   Node->getValueType(0), Tmp1); | 
 |     else | 
 |       Result = Op.getValue(0); | 
 |  | 
 |     // Since CopyFromReg produces two values, make sure to remember that we | 
 |     // legalized both of them. | 
 |     AddLegalizedOperand(Op.getValue(0), Result); | 
 |     AddLegalizedOperand(Op.getValue(1), Result.getValue(1)); | 
 |     return Result.getValue(Op.ResNo); | 
 |   case ISD::ImplicitDef: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     if (Tmp1 != Node->getOperand(0)) | 
 |       Result = DAG.getImplicitDef(Tmp1, cast<RegSDNode>(Node)->getReg()); | 
 |     break; | 
 |   case ISD::UNDEF: { | 
 |     MVT::ValueType VT = Op.getValueType(); | 
 |     switch (TLI.getOperationAction(ISD::UNDEF, VT)) { | 
 |     default: assert(0 && "This action is not supported yet!"); | 
 |     case TargetLowering::Expand: | 
 |     case TargetLowering::Promote: | 
 |       if (MVT::isInteger(VT)) | 
 |         Result = DAG.getConstant(0, VT); | 
 |       else if (MVT::isFloatingPoint(VT)) | 
 |         Result = DAG.getConstantFP(0, VT); | 
 |       else | 
 |         assert(0 && "Unknown value type!"); | 
 |       break; | 
 |     case TargetLowering::Legal: | 
 |       break; | 
 |     } | 
 |     break; | 
 |   } | 
 |   case ISD::Constant: | 
 |     // We know we don't need to expand constants here, constants only have one | 
 |     // value and we check that it is fine above. | 
 |  | 
 |     // FIXME: Maybe we should handle things like targets that don't support full | 
 |     // 32-bit immediates? | 
 |     break; | 
 |   case ISD::ConstantFP: { | 
 |     // Spill FP immediates to the constant pool if the target cannot directly | 
 |     // codegen them.  Targets often have some immediate values that can be | 
 |     // efficiently generated into an FP register without a load.  We explicitly | 
 |     // leave these constants as ConstantFP nodes for the target to deal with. | 
 |  | 
 |     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node); | 
 |  | 
 |     // Check to see if this FP immediate is already legal. | 
 |     bool isLegal = false; | 
 |     for (TargetLowering::legal_fpimm_iterator I = TLI.legal_fpimm_begin(), | 
 |            E = TLI.legal_fpimm_end(); I != E; ++I) | 
 |       if (CFP->isExactlyValue(*I)) { | 
 |         isLegal = true; | 
 |         break; | 
 |       } | 
 |  | 
 |     if (!isLegal) { | 
 |       // Otherwise we need to spill the constant to memory. | 
 |       MachineConstantPool *CP = DAG.getMachineFunction().getConstantPool(); | 
 |  | 
 |       bool Extend = false; | 
 |  | 
 |       // If a FP immediate is precise when represented as a float, we put it | 
 |       // into the constant pool as a float, even if it's is statically typed | 
 |       // as a double. | 
 |       MVT::ValueType VT = CFP->getValueType(0); | 
 |       bool isDouble = VT == MVT::f64; | 
 |       ConstantFP *LLVMC = ConstantFP::get(isDouble ? Type::DoubleTy : | 
 |                                              Type::FloatTy, CFP->getValue()); | 
 |       if (isDouble && CFP->isExactlyValue((float)CFP->getValue()) && | 
 |           // Only do this if the target has a native EXTLOAD instruction from | 
 |           // f32. | 
 |           TLI.getOperationAction(ISD::EXTLOAD, | 
 |                                  MVT::f32) == TargetLowering::Legal) { | 
 |         LLVMC = cast<ConstantFP>(ConstantExpr::getCast(LLVMC, Type::FloatTy)); | 
 |         VT = MVT::f32; | 
 |         Extend = true; | 
 |       } | 
 |  | 
 |       SDOperand CPIdx = DAG.getConstantPool(CP->getConstantPoolIndex(LLVMC), | 
 |                                             TLI.getPointerTy()); | 
 |       if (Extend) { | 
 |         Result = DAG.getNode(ISD::EXTLOAD, MVT::f64, DAG.getEntryNode(), CPIdx, | 
 |                              DAG.getSrcValue(NULL), MVT::f32); | 
 |       } else { | 
 |         Result = DAG.getLoad(VT, DAG.getEntryNode(), CPIdx, | 
 |                              DAG.getSrcValue(NULL)); | 
 |       } | 
 |     } | 
 |     break; | 
 |   } | 
 |   case ISD::TokenFactor: { | 
 |     std::vector<SDOperand> Ops; | 
 |     bool Changed = false; | 
 |     for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) { | 
 |       SDOperand Op = Node->getOperand(i); | 
 |       // Fold single-use TokenFactor nodes into this token factor as we go. | 
 |       // FIXME: This is something that the DAGCombiner should do!! | 
 |       if (Op.getOpcode() == ISD::TokenFactor && Op.hasOneUse()) { | 
 |         Changed = true; | 
 |         for (unsigned j = 0, e = Op.getNumOperands(); j != e; ++j) | 
 |           Ops.push_back(LegalizeOp(Op.getOperand(j))); | 
 |       } else { | 
 |         Ops.push_back(LegalizeOp(Op));  // Legalize the operands | 
 |         Changed |= Ops[i] != Op; | 
 |       } | 
 |     } | 
 |     if (Changed) | 
 |       Result = DAG.getNode(ISD::TokenFactor, MVT::Other, Ops); | 
 |     break; | 
 |   } | 
 |  | 
 |   case ISD::CALLSEQ_START: | 
 |   case ISD::CALLSEQ_END: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     // Do not try to legalize the target-specific arguments (#1+) | 
 |     Tmp2 = Node->getOperand(0); | 
 |     if (Tmp1 != Tmp2) { | 
 |       Node->setAdjCallChain(Tmp1); | 
 |  | 
 |       // If moving the operand from pointing to Tmp2 dropped its use count to 1, | 
 |       // this will cause the maps used to memoize results to get confused. | 
 |       // Create and add a dummy use, just to increase its use count.  This will | 
 |       // be removed at the end of legalize when dead nodes are removed. | 
 |       if (Tmp2.Val->hasOneUse()) | 
 |         DAG.getNode(ISD::PCMARKER, MVT::Other, Tmp2, | 
 |                     DAG.getConstant(0, MVT::i32)); | 
 |     } | 
 |     // Note that we do not create new CALLSEQ_DOWN/UP nodes here.  These | 
 |     // nodes are treated specially and are mutated in place.  This makes the dag | 
 |     // legalization process more efficient and also makes libcall insertion | 
 |     // easier. | 
 |     break; | 
 |   case ISD::DYNAMIC_STACKALLOC: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));  // Legalize the size. | 
 |     Tmp3 = LegalizeOp(Node->getOperand(2));  // Legalize the alignment. | 
 |     if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || | 
 |         Tmp3 != Node->getOperand(2)) | 
 |       Result = DAG.getNode(ISD::DYNAMIC_STACKALLOC, Node->getValueType(0), | 
 |                            Tmp1, Tmp2, Tmp3); | 
 |     else | 
 |       Result = Op.getValue(0); | 
 |  | 
 |     // Since this op produces two values, make sure to remember that we | 
 |     // legalized both of them. | 
 |     AddLegalizedOperand(SDOperand(Node, 0), Result); | 
 |     AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1)); | 
 |     return Result.getValue(Op.ResNo); | 
 |  | 
 |   case ISD::CALL: { | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));  // Legalize the callee. | 
 |  | 
 |     bool Changed = false; | 
 |     std::vector<SDOperand> Ops; | 
 |     for (unsigned i = 2, e = Node->getNumOperands(); i != e; ++i) { | 
 |       Ops.push_back(LegalizeOp(Node->getOperand(i))); | 
 |       Changed |= Ops.back() != Node->getOperand(i); | 
 |     } | 
 |  | 
 |     if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || Changed) { | 
 |       std::vector<MVT::ValueType> RetTyVTs; | 
 |       RetTyVTs.reserve(Node->getNumValues()); | 
 |       for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) | 
 |         RetTyVTs.push_back(Node->getValueType(i)); | 
 |       Result = SDOperand(DAG.getCall(RetTyVTs, Tmp1, Tmp2, Ops), 0); | 
 |     } else { | 
 |       Result = Result.getValue(0); | 
 |     } | 
 |     // Since calls produce multiple values, make sure to remember that we | 
 |     // legalized all of them. | 
 |     for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) | 
 |       AddLegalizedOperand(SDOperand(Node, i), Result.getValue(i)); | 
 |     return Result.getValue(Op.ResNo); | 
 |   } | 
 |   case ISD::BR: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     if (Tmp1 != Node->getOperand(0)) | 
 |       Result = DAG.getNode(ISD::BR, MVT::Other, Tmp1, Node->getOperand(1)); | 
 |     break; | 
 |  | 
 |   case ISD::BRCOND: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |  | 
 |     switch (getTypeAction(Node->getOperand(1).getValueType())) { | 
 |     case Expand: assert(0 && "It's impossible to expand bools"); | 
 |     case Legal: | 
 |       Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the condition. | 
 |       break; | 
 |     case Promote: | 
 |       Tmp2 = PromoteOp(Node->getOperand(1));  // Promote the condition. | 
 |       break; | 
 |     } | 
 |     // Basic block destination (Op#2) is always legal. | 
 |     if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) | 
 |       Result = DAG.getNode(ISD::BRCOND, MVT::Other, Tmp1, Tmp2, | 
 |                            Node->getOperand(2)); | 
 |     break; | 
 |   case ISD::BRCONDTWOWAY: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     switch (getTypeAction(Node->getOperand(1).getValueType())) { | 
 |     case Expand: assert(0 && "It's impossible to expand bools"); | 
 |     case Legal: | 
 |       Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the condition. | 
 |       break; | 
 |     case Promote: | 
 |       Tmp2 = PromoteOp(Node->getOperand(1));  // Promote the condition. | 
 |       break; | 
 |     } | 
 |     // If this target does not support BRCONDTWOWAY, lower it to a BRCOND/BR | 
 |     // pair. | 
 |     switch (TLI.getOperationAction(ISD::BRCONDTWOWAY, MVT::Other)) { | 
 |     case TargetLowering::Promote: | 
 |     default: assert(0 && "This action is not supported yet!"); | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) { | 
 |         std::vector<SDOperand> Ops; | 
 |         Ops.push_back(Tmp1); | 
 |         Ops.push_back(Tmp2); | 
 |         Ops.push_back(Node->getOperand(2)); | 
 |         Ops.push_back(Node->getOperand(3)); | 
 |         Result = DAG.getNode(ISD::BRCONDTWOWAY, MVT::Other, Ops); | 
 |       } | 
 |       break; | 
 |     case TargetLowering::Expand: | 
 |       Result = DAG.getNode(ISD::BRCOND, MVT::Other, Tmp1, Tmp2, | 
 |                            Node->getOperand(2)); | 
 |       Result = DAG.getNode(ISD::BR, MVT::Other, Result, Node->getOperand(3)); | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::LOAD: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));  // Legalize the pointer. | 
 |  | 
 |     if (Tmp1 != Node->getOperand(0) || | 
 |         Tmp2 != Node->getOperand(1)) | 
 |       Result = DAG.getLoad(Node->getValueType(0), Tmp1, Tmp2, | 
 |                            Node->getOperand(2)); | 
 |     else | 
 |       Result = SDOperand(Node, 0); | 
 |  | 
 |     // Since loads produce two values, make sure to remember that we legalized | 
 |     // both of them. | 
 |     AddLegalizedOperand(SDOperand(Node, 0), Result); | 
 |     AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1)); | 
 |     return Result.getValue(Op.ResNo); | 
 |  | 
 |   case ISD::EXTLOAD: | 
 |   case ISD::SEXTLOAD: | 
 |   case ISD::ZEXTLOAD: { | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));  // Legalize the pointer. | 
 |  | 
 |     MVT::ValueType SrcVT = cast<MVTSDNode>(Node)->getExtraValueType(); | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), SrcVT)) { | 
 |     default: assert(0 && "This action is not supported yet!"); | 
 |     case TargetLowering::Promote: | 
 |       assert(SrcVT == MVT::i1 && "Can only promote EXTLOAD from i1 -> i8!"); | 
 |       Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), | 
 |                            Tmp1, Tmp2, Node->getOperand(2), MVT::i8); | 
 |       // Since loads produce two values, make sure to remember that we legalized | 
 |       // both of them. | 
 |       AddLegalizedOperand(SDOperand(Node, 0), Result); | 
 |       AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1)); | 
 |       return Result.getValue(Op.ResNo); | 
 |  | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0) || | 
 |           Tmp2 != Node->getOperand(1)) | 
 |         Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), | 
 |                              Tmp1, Tmp2, Node->getOperand(2), SrcVT); | 
 |       else | 
 |         Result = SDOperand(Node, 0); | 
 |  | 
 |       // Since loads produce two values, make sure to remember that we legalized | 
 |       // both of them. | 
 |       AddLegalizedOperand(SDOperand(Node, 0), Result); | 
 |       AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1)); | 
 |       return Result.getValue(Op.ResNo); | 
 |     case TargetLowering::Expand: | 
 |       assert(Node->getOpcode() != ISD::EXTLOAD && | 
 |              "EXTLOAD should always be supported!"); | 
 |       // Turn the unsupported load into an EXTLOAD followed by an explicit | 
 |       // zero/sign extend inreg. | 
 |       Result = DAG.getNode(ISD::EXTLOAD, Node->getValueType(0), | 
 |                            Tmp1, Tmp2, Node->getOperand(2), SrcVT); | 
 |       SDOperand ValRes; | 
 |       if (Node->getOpcode() == ISD::SEXTLOAD) | 
 |         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, Result.getValueType(), | 
 |                              Result, SrcVT); | 
 |       else | 
 |         ValRes = DAG.getZeroExtendInReg(Result, SrcVT); | 
 |       AddLegalizedOperand(SDOperand(Node, 0), ValRes); | 
 |       AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1)); | 
 |       if (Op.ResNo) | 
 |         return Result.getValue(1); | 
 |       return ValRes; | 
 |     } | 
 |     assert(0 && "Unreachable"); | 
 |   } | 
 |   case ISD::EXTRACT_ELEMENT: | 
 |     // Get both the low and high parts. | 
 |     ExpandOp(Node->getOperand(0), Tmp1, Tmp2); | 
 |     if (cast<ConstantSDNode>(Node->getOperand(1))->getValue()) | 
 |       Result = Tmp2;  // 1 -> Hi | 
 |     else | 
 |       Result = Tmp1;  // 0 -> Lo | 
 |     break; | 
 |  | 
 |   case ISD::CopyToReg: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |  | 
 |     switch (getTypeAction(Node->getOperand(1).getValueType())) { | 
 |     case Legal: | 
 |       // Legalize the incoming value (must be legal). | 
 |       Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) | 
 |         Result = DAG.getCopyToReg(Tmp1, Tmp2, cast<RegSDNode>(Node)->getReg()); | 
 |       break; | 
 |     case Promote: | 
 |       Tmp2 = PromoteOp(Node->getOperand(1)); | 
 |       Result = DAG.getCopyToReg(Tmp1, Tmp2, cast<RegSDNode>(Node)->getReg()); | 
 |       break; | 
 |     case Expand: | 
 |       SDOperand Lo, Hi; | 
 |       ExpandOp(Node->getOperand(1), Lo, Hi); | 
 |       unsigned Reg = cast<RegSDNode>(Node)->getReg(); | 
 |       Lo = DAG.getCopyToReg(Tmp1, Lo, Reg); | 
 |       Hi = DAG.getCopyToReg(Tmp1, Hi, Reg+1); | 
 |       // Note that the copytoreg nodes are independent of each other. | 
 |       Result = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo, Hi); | 
 |       assert(isTypeLegal(Result.getValueType()) && | 
 |              "Cannot expand multiple times yet (i64 -> i16)"); | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::RET: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     switch (Node->getNumOperands()) { | 
 |     case 2:  // ret val | 
 |       switch (getTypeAction(Node->getOperand(1).getValueType())) { | 
 |       case Legal: | 
 |         Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |         if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) | 
 |           Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Tmp2); | 
 |         break; | 
 |       case Expand: { | 
 |         SDOperand Lo, Hi; | 
 |         ExpandOp(Node->getOperand(1), Lo, Hi); | 
 |         Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Lo, Hi); | 
 |         break; | 
 |       } | 
 |       case Promote: | 
 |         Tmp2 = PromoteOp(Node->getOperand(1)); | 
 |         Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1, Tmp2); | 
 |         break; | 
 |       } | 
 |       break; | 
 |     case 1:  // ret void | 
 |       if (Tmp1 != Node->getOperand(0)) | 
 |         Result = DAG.getNode(ISD::RET, MVT::Other, Tmp1); | 
 |       break; | 
 |     default: { // ret <values> | 
 |       std::vector<SDOperand> NewValues; | 
 |       NewValues.push_back(Tmp1); | 
 |       for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) | 
 |         switch (getTypeAction(Node->getOperand(i).getValueType())) { | 
 |         case Legal: | 
 |           NewValues.push_back(LegalizeOp(Node->getOperand(i))); | 
 |           break; | 
 |         case Expand: { | 
 |           SDOperand Lo, Hi; | 
 |           ExpandOp(Node->getOperand(i), Lo, Hi); | 
 |           NewValues.push_back(Lo); | 
 |           NewValues.push_back(Hi); | 
 |           break; | 
 |         } | 
 |         case Promote: | 
 |           assert(0 && "Can't promote multiple return value yet!"); | 
 |         } | 
 |       Result = DAG.getNode(ISD::RET, MVT::Other, NewValues); | 
 |       break; | 
 |     } | 
 |     } | 
 |     break; | 
 |   case ISD::STORE: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     Tmp2 = LegalizeOp(Node->getOperand(2));  // Legalize the pointer. | 
 |  | 
 |     // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr' | 
 |     if (ConstantFPSDNode *CFP =dyn_cast<ConstantFPSDNode>(Node->getOperand(1))){ | 
 |       if (CFP->getValueType(0) == MVT::f32) { | 
 |         union { | 
 |           unsigned I; | 
 |           float    F; | 
 |         } V; | 
 |         V.F = CFP->getValue(); | 
 |         Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,  | 
 |                              DAG.getConstant(V.I, MVT::i32), Tmp2, | 
 |                              Node->getOperand(3)); | 
 |       } else { | 
 |         assert(CFP->getValueType(0) == MVT::f64 && "Unknown FP type!"); | 
 |         union { | 
 |           uint64_t I; | 
 |           double   F; | 
 |         } V; | 
 |         V.F = CFP->getValue(); | 
 |         Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,  | 
 |                              DAG.getConstant(V.I, MVT::i64), Tmp2, | 
 |                              Node->getOperand(3)); | 
 |       } | 
 |       Node = Result.Val; | 
 |     } | 
 |  | 
 |     switch (getTypeAction(Node->getOperand(1).getValueType())) { | 
 |     case Legal: { | 
 |       SDOperand Val = LegalizeOp(Node->getOperand(1)); | 
 |       if (Val != Node->getOperand(1) || Tmp1 != Node->getOperand(0) || | 
 |           Tmp2 != Node->getOperand(2)) | 
 |         Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Val, Tmp2, | 
 |                              Node->getOperand(3)); | 
 |       break; | 
 |     } | 
 |     case Promote: | 
 |       // Truncate the value and store the result. | 
 |       Tmp3 = PromoteOp(Node->getOperand(1)); | 
 |       Result = DAG.getNode(ISD::TRUNCSTORE, MVT::Other, Tmp1, Tmp3, Tmp2, | 
 |                            Node->getOperand(3), | 
 |                            Node->getOperand(1).getValueType());  | 
 |       break; | 
 |  | 
 |     case Expand: | 
 |       SDOperand Lo, Hi; | 
 |       ExpandOp(Node->getOperand(1), Lo, Hi); | 
 |  | 
 |       if (!TLI.isLittleEndian()) | 
 |         std::swap(Lo, Hi); | 
 |  | 
 |       Lo = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Lo, Tmp2, | 
 |                        Node->getOperand(3)); | 
 |       unsigned IncrementSize = MVT::getSizeInBits(Hi.getValueType())/8; | 
 |       Tmp2 = DAG.getNode(ISD::ADD, Tmp2.getValueType(), Tmp2, | 
 |                          getIntPtrConstant(IncrementSize)); | 
 |       assert(isTypeLegal(Tmp2.getValueType()) && | 
 |              "Pointers must be legal!"); | 
 |       //Again, claiming both parts of the store came form the same Instr | 
 |       Hi = DAG.getNode(ISD::STORE, MVT::Other, Tmp1, Hi, Tmp2, | 
 |                        Node->getOperand(3)); | 
 |       Result = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo, Hi); | 
 |       break; | 
 |     } | 
 |     break; | 
 |   case ISD::PCMARKER: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     if (Tmp1 != Node->getOperand(0)) | 
 |       Result = DAG.getNode(ISD::PCMARKER, MVT::Other, Tmp1,Node->getOperand(1)); | 
 |     break; | 
 |   case ISD::TRUNCSTORE: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     Tmp3 = LegalizeOp(Node->getOperand(2));  // Legalize the pointer. | 
 |  | 
 |     switch (getTypeAction(Node->getOperand(1).getValueType())) { | 
 |     case Legal: | 
 |       Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || | 
 |           Tmp3 != Node->getOperand(2)) | 
 |         Result = DAG.getNode(ISD::TRUNCSTORE, MVT::Other, Tmp1, Tmp2, Tmp3, | 
 |                              Node->getOperand(3), | 
 |                              cast<MVTSDNode>(Node)->getExtraValueType()); | 
 |       break; | 
 |     case Promote: | 
 |     case Expand: | 
 |       assert(0 && "Cannot handle illegal TRUNCSTORE yet!"); | 
 |     } | 
 |     break; | 
 |   case ISD::SELECT: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Expand: assert(0 && "It's impossible to expand bools"); | 
 |     case Legal: | 
 |       Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the condition. | 
 |       break; | 
 |     case Promote: | 
 |       Tmp1 = PromoteOp(Node->getOperand(0));  // Promote the condition. | 
 |       break; | 
 |     } | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));   // TrueVal | 
 |     Tmp3 = LegalizeOp(Node->getOperand(2));   // FalseVal | 
 |  | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), Tmp2.getValueType())) { | 
 |     default: assert(0 && "This action is not supported yet!"); | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || | 
 |           Tmp3 != Node->getOperand(2)) | 
 |         Result = DAG.getNode(ISD::SELECT, Node->getValueType(0), | 
 |                              Tmp1, Tmp2, Tmp3); | 
 |       break; | 
 |     case TargetLowering::Promote: { | 
 |       MVT::ValueType NVT = | 
 |         TLI.getTypeToPromoteTo(ISD::SELECT, Tmp2.getValueType()); | 
 |       unsigned ExtOp, TruncOp; | 
 |       if (MVT::isInteger(Tmp2.getValueType())) { | 
 |         ExtOp = ISD::ZERO_EXTEND; | 
 |         TruncOp  = ISD::TRUNCATE; | 
 |       } else { | 
 |         ExtOp = ISD::FP_EXTEND; | 
 |         TruncOp  = ISD::FP_ROUND; | 
 |       } | 
 |       // Promote each of the values to the new type. | 
 |       Tmp2 = DAG.getNode(ExtOp, NVT, Tmp2); | 
 |       Tmp3 = DAG.getNode(ExtOp, NVT, Tmp3); | 
 |       // Perform the larger operation, then round down. | 
 |       Result = DAG.getNode(ISD::SELECT, NVT, Tmp1, Tmp2,Tmp3); | 
 |       Result = DAG.getNode(TruncOp, Node->getValueType(0), Result); | 
 |       break; | 
 |     } | 
 |     } | 
 |     break; | 
 |   case ISD::SETCC: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Legal: | 
 |       Tmp1 = LegalizeOp(Node->getOperand(0));   // LHS | 
 |       Tmp2 = LegalizeOp(Node->getOperand(1));   // RHS | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) | 
 |         Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), | 
 |                               Node->getValueType(0), Tmp1, Tmp2); | 
 |       break; | 
 |     case Promote: | 
 |       Tmp1 = PromoteOp(Node->getOperand(0));   // LHS | 
 |       Tmp2 = PromoteOp(Node->getOperand(1));   // RHS | 
 |  | 
 |       // If this is an FP compare, the operands have already been extended. | 
 |       if (MVT::isInteger(Node->getOperand(0).getValueType())) { | 
 |         MVT::ValueType VT = Node->getOperand(0).getValueType(); | 
 |         MVT::ValueType NVT = TLI.getTypeToTransformTo(VT); | 
 |  | 
 |         // Otherwise, we have to insert explicit sign or zero extends.  Note | 
 |         // that we could insert sign extends for ALL conditions, but zero extend | 
 |         // is cheaper on many machines (an AND instead of two shifts), so prefer | 
 |         // it. | 
 |         switch (cast<SetCCSDNode>(Node)->getCondition()) { | 
 |         default: assert(0 && "Unknown integer comparison!"); | 
 |         case ISD::SETEQ: | 
 |         case ISD::SETNE: | 
 |         case ISD::SETUGE: | 
 |         case ISD::SETUGT: | 
 |         case ISD::SETULE: | 
 |         case ISD::SETULT: | 
 |           // ALL of these operations will work if we either sign or zero extend | 
 |           // the operands (including the unsigned comparisons!).  Zero extend is | 
 |           // usually a simpler/cheaper operation, so prefer it. | 
 |           Tmp1 = DAG.getZeroExtendInReg(Tmp1, VT); | 
 |           Tmp2 = DAG.getZeroExtendInReg(Tmp2, VT); | 
 |           break; | 
 |         case ISD::SETGE: | 
 |         case ISD::SETGT: | 
 |         case ISD::SETLT: | 
 |         case ISD::SETLE: | 
 |           Tmp1 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp1, VT); | 
 |           Tmp2 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp2, VT); | 
 |           break; | 
 |         } | 
 |  | 
 |       } | 
 |       Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), | 
 |                             Node->getValueType(0), Tmp1, Tmp2); | 
 |       break; | 
 |     case Expand: | 
 |       SDOperand LHSLo, LHSHi, RHSLo, RHSHi; | 
 |       ExpandOp(Node->getOperand(0), LHSLo, LHSHi); | 
 |       ExpandOp(Node->getOperand(1), RHSLo, RHSHi); | 
 |       switch (cast<SetCCSDNode>(Node)->getCondition()) { | 
 |       case ISD::SETEQ: | 
 |       case ISD::SETNE: | 
 |         if (RHSLo == RHSHi) | 
 |           if (ConstantSDNode *RHSCST = dyn_cast<ConstantSDNode>(RHSLo)) | 
 |             if (RHSCST->isAllOnesValue()) { | 
 |               // Comparison to -1. | 
 |               Tmp1 = DAG.getNode(ISD::AND, LHSLo.getValueType(), LHSLo, LHSHi); | 
 |               Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), | 
 |                                     Node->getValueType(0), Tmp1, RHSLo); | 
 |               break; | 
 |             } | 
 |  | 
 |         Tmp1 = DAG.getNode(ISD::XOR, LHSLo.getValueType(), LHSLo, RHSLo); | 
 |         Tmp2 = DAG.getNode(ISD::XOR, LHSLo.getValueType(), LHSHi, RHSHi); | 
 |         Tmp1 = DAG.getNode(ISD::OR, Tmp1.getValueType(), Tmp1, Tmp2); | 
 |         Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), | 
 |                               Node->getValueType(0), Tmp1, | 
 |                               DAG.getConstant(0, Tmp1.getValueType())); | 
 |         break; | 
 |       default: | 
 |         // If this is a comparison of the sign bit, just look at the top part. | 
 |         // X > -1,  x < 0 | 
 |         if (ConstantSDNode *CST = dyn_cast<ConstantSDNode>(Node->getOperand(1))) | 
 |           if ((cast<SetCCSDNode>(Node)->getCondition() == ISD::SETLT && | 
 |                CST->getValue() == 0) ||              // X < 0 | 
 |               (cast<SetCCSDNode>(Node)->getCondition() == ISD::SETGT && | 
 |                (CST->isAllOnesValue())))             // X > -1 | 
 |             return DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), | 
 |                                 Node->getValueType(0), LHSHi, RHSHi); | 
 |  | 
 |         // FIXME: This generated code sucks. | 
 |         ISD::CondCode LowCC; | 
 |         switch (cast<SetCCSDNode>(Node)->getCondition()) { | 
 |         default: assert(0 && "Unknown integer setcc!"); | 
 |         case ISD::SETLT: | 
 |         case ISD::SETULT: LowCC = ISD::SETULT; break; | 
 |         case ISD::SETGT: | 
 |         case ISD::SETUGT: LowCC = ISD::SETUGT; break; | 
 |         case ISD::SETLE: | 
 |         case ISD::SETULE: LowCC = ISD::SETULE; break; | 
 |         case ISD::SETGE: | 
 |         case ISD::SETUGE: LowCC = ISD::SETUGE; break; | 
 |         } | 
 |  | 
 |         // Tmp1 = lo(op1) < lo(op2)   // Always unsigned comparison | 
 |         // Tmp2 = hi(op1) < hi(op2)   // Signedness depends on operands | 
 |         // dest = hi(op1) == hi(op2) ? Tmp1 : Tmp2; | 
 |  | 
 |         // NOTE: on targets without efficient SELECT of bools, we can always use | 
 |         // this identity: (B1 ? B2 : B3) --> (B1 & B2)|(!B1&B3) | 
 |         Tmp1 = DAG.getSetCC(LowCC, Node->getValueType(0), LHSLo, RHSLo); | 
 |         Tmp2 = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), | 
 |                             Node->getValueType(0), LHSHi, RHSHi); | 
 |         Result = DAG.getSetCC(ISD::SETEQ, Node->getValueType(0), LHSHi, RHSHi); | 
 |         Result = DAG.getNode(ISD::SELECT, Tmp1.getValueType(), | 
 |                              Result, Tmp1, Tmp2); | 
 |         break; | 
 |       } | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::MEMSET: | 
 |   case ISD::MEMCPY: | 
 |   case ISD::MEMMOVE: { | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));      // Chain | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));      // Pointer | 
 |  | 
 |     if (Node->getOpcode() == ISD::MEMSET) {      // memset = ubyte | 
 |       switch (getTypeAction(Node->getOperand(2).getValueType())) { | 
 |       case Expand: assert(0 && "Cannot expand a byte!"); | 
 |       case Legal: | 
 |         Tmp3 = LegalizeOp(Node->getOperand(2)); | 
 |         break; | 
 |       case Promote: | 
 |         Tmp3 = PromoteOp(Node->getOperand(2)); | 
 |         break; | 
 |       } | 
 |     } else { | 
 |       Tmp3 = LegalizeOp(Node->getOperand(2));    // memcpy/move = pointer, | 
 |     } | 
 |  | 
 |     SDOperand Tmp4; | 
 |     switch (getTypeAction(Node->getOperand(3).getValueType())) { | 
 |     case Expand: assert(0 && "Cannot expand this yet!"); | 
 |     case Legal: | 
 |       Tmp4 = LegalizeOp(Node->getOperand(3)); | 
 |       break; | 
 |     case Promote: | 
 |       Tmp4 = PromoteOp(Node->getOperand(3)); | 
 |       break; | 
 |     } | 
 |  | 
 |     SDOperand Tmp5; | 
 |     switch (getTypeAction(Node->getOperand(4).getValueType())) {  // uint | 
 |     case Expand: assert(0 && "Cannot expand this yet!"); | 
 |     case Legal: | 
 |       Tmp5 = LegalizeOp(Node->getOperand(4)); | 
 |       break; | 
 |     case Promote: | 
 |       Tmp5 = PromoteOp(Node->getOperand(4)); | 
 |       break; | 
 |     } | 
 |  | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), MVT::Other)) { | 
 |     default: assert(0 && "This action not implemented for this operation!"); | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || | 
 |           Tmp3 != Node->getOperand(2) || Tmp4 != Node->getOperand(3) || | 
 |           Tmp5 != Node->getOperand(4)) { | 
 |         std::vector<SDOperand> Ops; | 
 |         Ops.push_back(Tmp1); Ops.push_back(Tmp2); Ops.push_back(Tmp3); | 
 |         Ops.push_back(Tmp4); Ops.push_back(Tmp5); | 
 |         Result = DAG.getNode(Node->getOpcode(), MVT::Other, Ops); | 
 |       } | 
 |       break; | 
 |     case TargetLowering::Expand: { | 
 |       // Otherwise, the target does not support this operation.  Lower the | 
 |       // operation to an explicit libcall as appropriate. | 
 |       MVT::ValueType IntPtr = TLI.getPointerTy(); | 
 |       const Type *IntPtrTy = TLI.getTargetData().getIntPtrType(); | 
 |       std::vector<std::pair<SDOperand, const Type*> > Args; | 
 |  | 
 |       const char *FnName = 0; | 
 |       if (Node->getOpcode() == ISD::MEMSET) { | 
 |         Args.push_back(std::make_pair(Tmp2, IntPtrTy)); | 
 |         // Extend the ubyte argument to be an int value for the call. | 
 |         Tmp3 = DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Tmp3); | 
 |         Args.push_back(std::make_pair(Tmp3, Type::IntTy)); | 
 |         Args.push_back(std::make_pair(Tmp4, IntPtrTy)); | 
 |  | 
 |         FnName = "memset"; | 
 |       } else if (Node->getOpcode() == ISD::MEMCPY || | 
 |                  Node->getOpcode() == ISD::MEMMOVE) { | 
 |         Args.push_back(std::make_pair(Tmp2, IntPtrTy)); | 
 |         Args.push_back(std::make_pair(Tmp3, IntPtrTy)); | 
 |         Args.push_back(std::make_pair(Tmp4, IntPtrTy)); | 
 |         FnName = Node->getOpcode() == ISD::MEMMOVE ? "memmove" : "memcpy"; | 
 |       } else { | 
 |         assert(0 && "Unknown op!"); | 
 |       } | 
 |  | 
 |       std::pair<SDOperand,SDOperand> CallResult = | 
 |         TLI.LowerCallTo(Tmp1, Type::VoidTy, false, 0, | 
 |                         DAG.getExternalSymbol(FnName, IntPtr), Args, DAG); | 
 |       Result = LegalizeOp(CallResult.second); | 
 |       break; | 
 |     } | 
 |     case TargetLowering::Custom: | 
 |       std::vector<SDOperand> Ops; | 
 |       Ops.push_back(Tmp1); Ops.push_back(Tmp2); Ops.push_back(Tmp3); | 
 |       Ops.push_back(Tmp4); Ops.push_back(Tmp5); | 
 |       Result = DAG.getNode(Node->getOpcode(), MVT::Other, Ops); | 
 |       Result = TLI.LowerOperation(Result); | 
 |       Result = LegalizeOp(Result); | 
 |       break; | 
 |     } | 
 |     break; | 
 |   } | 
 |  | 
 |   case ISD::READPORT: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |  | 
 |     if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) | 
 |       Result = DAG.getNode(ISD::READPORT, Node->getValueType(0), Tmp1, Tmp2); | 
 |     else | 
 |       Result = SDOperand(Node, 0); | 
 |     // Since these produce two values, make sure to remember that we legalized | 
 |     // both of them. | 
 |     AddLegalizedOperand(SDOperand(Node, 0), Result); | 
 |     AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1)); | 
 |     return Result.getValue(Op.ResNo); | 
 |   case ISD::WRITEPORT: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |     Tmp3 = LegalizeOp(Node->getOperand(2)); | 
 |     if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || | 
 |         Tmp3 != Node->getOperand(2)) | 
 |       Result = DAG.getNode(Node->getOpcode(), MVT::Other, Tmp1, Tmp2, Tmp3); | 
 |     break; | 
 |  | 
 |   case ISD::READIO: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |  | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0))) { | 
 |     case TargetLowering::Custom: | 
 |     default: assert(0 && "This action not implemented for this operation!"); | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1)) | 
 |         Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), | 
 |                              Tmp1, Tmp2); | 
 |       else | 
 |         Result = SDOperand(Node, 0); | 
 |       break; | 
 |     case TargetLowering::Expand: | 
 |       // Replace this with a load from memory. | 
 |       Result = DAG.getLoad(Node->getValueType(0), Node->getOperand(0), | 
 |                            Node->getOperand(1), DAG.getSrcValue(NULL)); | 
 |       Result = LegalizeOp(Result); | 
 |       break; | 
 |     } | 
 |  | 
 |     // Since these produce two values, make sure to remember that we legalized | 
 |     // both of them. | 
 |     AddLegalizedOperand(SDOperand(Node, 0), Result); | 
 |     AddLegalizedOperand(SDOperand(Node, 1), Result.getValue(1)); | 
 |     return Result.getValue(Op.ResNo); | 
 |  | 
 |   case ISD::WRITEIO: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |     Tmp3 = LegalizeOp(Node->getOperand(2)); | 
 |  | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), | 
 |                                    Node->getOperand(1).getValueType())) { | 
 |     case TargetLowering::Custom: | 
 |     default: assert(0 && "This action not implemented for this operation!"); | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1) || | 
 |           Tmp3 != Node->getOperand(2)) | 
 |         Result = DAG.getNode(Node->getOpcode(), MVT::Other, Tmp1, Tmp2, Tmp3); | 
 |       break; | 
 |     case TargetLowering::Expand: | 
 |       // Replace this with a store to memory. | 
 |       Result = DAG.getNode(ISD::STORE, MVT::Other, Node->getOperand(0), | 
 |                            Node->getOperand(1), Node->getOperand(2), | 
 |                            DAG.getSrcValue(NULL)); | 
 |       Result = LegalizeOp(Result); | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::ADD_PARTS: | 
 |   case ISD::SUB_PARTS: | 
 |   case ISD::SHL_PARTS: | 
 |   case ISD::SRA_PARTS: | 
 |   case ISD::SRL_PARTS: { | 
 |     std::vector<SDOperand> Ops; | 
 |     bool Changed = false; | 
 |     for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) { | 
 |       Ops.push_back(LegalizeOp(Node->getOperand(i))); | 
 |       Changed |= Ops.back() != Node->getOperand(i); | 
 |     } | 
 |     if (Changed) | 
 |       Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Ops); | 
 |  | 
 |     // Since these produce multiple values, make sure to remember that we | 
 |     // legalized all of them. | 
 |     for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) | 
 |       AddLegalizedOperand(SDOperand(Node, i), Result.getValue(i)); | 
 |     return Result.getValue(Op.ResNo); | 
 |   } | 
 |  | 
 |     // Binary operators | 
 |   case ISD::ADD: | 
 |   case ISD::SUB: | 
 |   case ISD::MUL: | 
 |   case ISD::MULHS: | 
 |   case ISD::MULHU: | 
 |   case ISD::UDIV: | 
 |   case ISD::SDIV: | 
 |   case ISD::AND: | 
 |   case ISD::OR: | 
 |   case ISD::XOR: | 
 |   case ISD::SHL: | 
 |   case ISD::SRL: | 
 |   case ISD::SRA: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));   // LHS | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));   // RHS | 
 |     if (Tmp1 != Node->getOperand(0) || | 
 |         Tmp2 != Node->getOperand(1)) | 
 |       Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1,Tmp2); | 
 |     break; | 
 |  | 
 |   case ISD::UREM: | 
 |   case ISD::SREM: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));   // LHS | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));   // RHS | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0))) { | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0) || | 
 |           Tmp2 != Node->getOperand(1)) | 
 |         Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1, | 
 |                              Tmp2); | 
 |       break; | 
 |     case TargetLowering::Promote: | 
 |     case TargetLowering::Custom: | 
 |       assert(0 && "Cannot promote/custom handle this yet!"); | 
 |     case TargetLowering::Expand: { | 
 |       MVT::ValueType VT = Node->getValueType(0); | 
 |       unsigned Opc = (Node->getOpcode() == ISD::UREM) ? ISD::UDIV : ISD::SDIV; | 
 |       Result = DAG.getNode(Opc, VT, Tmp1, Tmp2); | 
 |       Result = DAG.getNode(ISD::MUL, VT, Result, Tmp2); | 
 |       Result = DAG.getNode(ISD::SUB, VT, Tmp1, Result); | 
 |       } | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::CTPOP: | 
 |   case ISD::CTTZ: | 
 |   case ISD::CTLZ: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));   // Op | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0))) { | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0)) | 
 |         Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1); | 
 |       break; | 
 |     case TargetLowering::Promote: { | 
 |       MVT::ValueType OVT = Tmp1.getValueType(); | 
 |       MVT::ValueType NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT); | 
 |  | 
 |       // Zero extend the argument. | 
 |       Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, NVT, Tmp1); | 
 |       // Perform the larger operation, then subtract if needed. | 
 |       Tmp1 = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1); | 
 |       switch(Node->getOpcode()) | 
 |       { | 
 |       case ISD::CTPOP: | 
 |         Result = Tmp1; | 
 |         break; | 
 |       case ISD::CTTZ: | 
 |         //if Tmp1 == sizeinbits(NVT) then Tmp1 = sizeinbits(Old VT) | 
 |         Tmp2 = DAG.getSetCC(ISD::SETEQ, TLI.getSetCCResultTy(), Tmp1,  | 
 |                             DAG.getConstant(getSizeInBits(NVT), NVT)); | 
 |         Result = DAG.getNode(ISD::SELECT, NVT, Tmp2,  | 
 |                            DAG.getConstant(getSizeInBits(OVT),NVT), Tmp1); | 
 |         break; | 
 |       case ISD::CTLZ: | 
 |         //Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT)) | 
 |         Result = DAG.getNode(ISD::SUB, NVT, Tmp1,  | 
 |                              DAG.getConstant(getSizeInBits(NVT) -  | 
 |                                              getSizeInBits(OVT), NVT)); | 
 |         break; | 
 |       } | 
 |       break; | 
 |     } | 
 |     case TargetLowering::Custom: | 
 |       assert(0 && "Cannot custom handle this yet!"); | 
 |     case TargetLowering::Expand: | 
 |       switch(Node->getOpcode()) | 
 |       { | 
 |       case ISD::CTPOP: { | 
 |         static const uint64_t mask[6] = { | 
 |           0x5555555555555555ULL, 0x3333333333333333ULL, | 
 |           0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, | 
 |           0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL | 
 |         }; | 
 |         MVT::ValueType VT = Tmp1.getValueType(); | 
 |         MVT::ValueType ShVT = TLI.getShiftAmountTy(); | 
 |         unsigned len = getSizeInBits(VT); | 
 |         for (unsigned i = 0; (1U << i) <= (len / 2); ++i) { | 
 |           //x = (x & mask[i][len/8]) + (x >> (1 << i) & mask[i][len/8]) | 
 |           Tmp2 = DAG.getConstant(mask[i], VT); | 
 |           Tmp3 = DAG.getConstant(1ULL << i, ShVT); | 
 |           Tmp1 = DAG.getNode(ISD::ADD, VT,  | 
 |                              DAG.getNode(ISD::AND, VT, Tmp1, Tmp2), | 
 |                              DAG.getNode(ISD::AND, VT, | 
 |                                          DAG.getNode(ISD::SRL, VT, Tmp1, Tmp3), | 
 |                                          Tmp2)); | 
 |         } | 
 |         Result = Tmp1; | 
 |         break; | 
 |       } | 
 |       case ISD::CTLZ: { | 
 |         /* for now, we do this: | 
 |            x = x | (x >> 1); | 
 |            x = x | (x >> 2); | 
 |            ... | 
 |            x = x | (x >>16); | 
 |            x = x | (x >>32); // for 64-bit input  | 
 |            return popcount(~x); | 
 |          | 
 |            but see also: http://www.hackersdelight.org/HDcode/nlz.cc */ | 
 |         MVT::ValueType VT = Tmp1.getValueType(); | 
 |         MVT::ValueType ShVT = TLI.getShiftAmountTy(); | 
 |         unsigned len = getSizeInBits(VT); | 
 |         for (unsigned i = 0; (1U << i) <= (len / 2); ++i) { | 
 |           Tmp3 = DAG.getConstant(1ULL << i, ShVT); | 
 |           Tmp1 = DAG.getNode(ISD::OR, VT, Tmp1,   | 
 |                              DAG.getNode(ISD::SRL, VT, Tmp1, Tmp3)); | 
 |         } | 
 |         Tmp3 = DAG.getNode(ISD::XOR, VT, Tmp1, DAG.getConstant(~0ULL, VT)); | 
 |         Result = LegalizeOp(DAG.getNode(ISD::CTPOP, VT, Tmp3)); | 
 |         break; | 
 |       } | 
 |       case ISD::CTTZ: { | 
 |         // for now, we use: { return popcount(~x & (x - 1)); }  | 
 |         // unless the target has ctlz but not ctpop, in which case we use: | 
 |         // { return 32 - nlz(~x & (x-1)); } | 
 |         // see also http://www.hackersdelight.org/HDcode/ntz.cc | 
 |         MVT::ValueType VT = Tmp1.getValueType(); | 
 |         Tmp2 = DAG.getConstant(~0ULL, VT); | 
 |         Tmp3 = DAG.getNode(ISD::AND, VT,  | 
 |                            DAG.getNode(ISD::XOR, VT, Tmp1, Tmp2), | 
 |                            DAG.getNode(ISD::SUB, VT, Tmp1, | 
 |                                        DAG.getConstant(1, VT))); | 
 |         // If ISD::CTLZ is legal and CTPOP isn't, then do that instead | 
 |         if (TLI.getOperationAction(ISD::CTPOP, VT) != TargetLowering::Legal && | 
 |             TLI.getOperationAction(ISD::CTLZ, VT) == TargetLowering::Legal) { | 
 |           Result = LegalizeOp(DAG.getNode(ISD::SUB, VT,  | 
 |                                         DAG.getConstant(getSizeInBits(VT), VT), | 
 |                                         DAG.getNode(ISD::CTLZ, VT, Tmp3))); | 
 |         } else { | 
 |           Result = LegalizeOp(DAG.getNode(ISD::CTPOP, VT, Tmp3)); | 
 |         } | 
 |         break; | 
 |       } | 
 |       default: | 
 |         assert(0 && "Cannot expand this yet!"); | 
 |         break; | 
 |       } | 
 |       break; | 
 |     } | 
 |     break; | 
 |      | 
 |     // Unary operators | 
 |   case ISD::FABS: | 
 |   case ISD::FNEG: | 
 |   case ISD::FSQRT: | 
 |   case ISD::FSIN: | 
 |   case ISD::FCOS: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0))) { | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0)) | 
 |         Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1); | 
 |       break; | 
 |     case TargetLowering::Promote: | 
 |     case TargetLowering::Custom: | 
 |       assert(0 && "Cannot promote/custom handle this yet!"); | 
 |     case TargetLowering::Expand: | 
 |       switch(Node->getOpcode()) { | 
 |       case ISD::FNEG: { | 
 |         // Expand Y = FNEG(X) ->  Y = SUB -0.0, X | 
 |         Tmp2 = DAG.getConstantFP(-0.0, Node->getValueType(0)); | 
 |         Result = LegalizeOp(DAG.getNode(ISD::SUB, Node->getValueType(0), | 
 |                                         Tmp2, Tmp1)); | 
 |         break; | 
 |       } | 
 |       case ISD::FABS: { | 
 |         // Expand Y = FABS(X) -> Y = (X >u 0.0) ? X : fneg(X). | 
 |         MVT::ValueType VT = Node->getValueType(0); | 
 |         Tmp2 = DAG.getConstantFP(0.0, VT); | 
 |         Tmp2 = DAG.getSetCC(ISD::SETUGT, TLI.getSetCCResultTy(), Tmp1, Tmp2); | 
 |         Tmp3 = DAG.getNode(ISD::FNEG, VT, Tmp1); | 
 |         Result = DAG.getNode(ISD::SELECT, VT, Tmp2, Tmp1, Tmp3); | 
 |         Result = LegalizeOp(Result); | 
 |         break; | 
 |       } | 
 |       case ISD::FSQRT: | 
 |       case ISD::FSIN: | 
 |       case ISD::FCOS: { | 
 |         MVT::ValueType VT = Node->getValueType(0); | 
 |         Type *T = VT == MVT::f32 ? Type::FloatTy : Type::DoubleTy; | 
 |         const char *FnName = 0; | 
 |         switch(Node->getOpcode()) { | 
 |         case ISD::FSQRT: FnName = VT == MVT::f32 ? "sqrtf" : "sqrt"; break; | 
 |         case ISD::FSIN:  FnName = VT == MVT::f32 ? "sinf"  : "sin"; break; | 
 |         case ISD::FCOS:  FnName = VT == MVT::f32 ? "cosf"  : "cos"; break; | 
 |         default: assert(0 && "Unreachable!"); | 
 |         } | 
 |         std::vector<std::pair<SDOperand, const Type*> > Args; | 
 |         Args.push_back(std::make_pair(Tmp1, T)); | 
 |         // FIXME: should use ExpandLibCall! | 
 |         std::pair<SDOperand,SDOperand> CallResult = | 
 |           TLI.LowerCallTo(DAG.getEntryNode(), T, false, 0, | 
 |                           DAG.getExternalSymbol(FnName, VT), Args, DAG); | 
 |         Result = LegalizeOp(CallResult.first); | 
 |         break; | 
 |       } | 
 |       default: | 
 |         assert(0 && "Unreachable!"); | 
 |       } | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |     // Conversion operators.  The source and destination have different types. | 
 |   case ISD::ZERO_EXTEND: | 
 |   case ISD::SIGN_EXTEND: | 
 |   case ISD::TRUNCATE: | 
 |   case ISD::FP_EXTEND: | 
 |   case ISD::FP_ROUND: | 
 |   case ISD::FP_TO_SINT: | 
 |   case ISD::FP_TO_UINT: | 
 |   case ISD::SINT_TO_FP: | 
 |   case ISD::UINT_TO_FP: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Legal: | 
 |       Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |       if (Tmp1 != Node->getOperand(0)) | 
 |         Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1); | 
 |       break; | 
 |     case Expand: | 
 |       if (Node->getOpcode() == ISD::SINT_TO_FP || | 
 |           Node->getOpcode() == ISD::UINT_TO_FP) { | 
 |         Result = ExpandIntToFP(Node->getOpcode() == ISD::SINT_TO_FP, | 
 |                                Node->getValueType(0), Node->getOperand(0)); | 
 |         break; | 
 |       } else if (Node->getOpcode() == ISD::TRUNCATE) { | 
 |         // In the expand case, we must be dealing with a truncate, because | 
 |         // otherwise the result would be larger than the source. | 
 |         ExpandOp(Node->getOperand(0), Tmp1, Tmp2); | 
 |  | 
 |         // Since the result is legal, we should just be able to truncate the low | 
 |         // part of the source. | 
 |         Result = DAG.getNode(ISD::TRUNCATE, Node->getValueType(0), Tmp1); | 
 |         break; | 
 |       } | 
 |       assert(0 && "Shouldn't need to expand other operators here!"); | 
 |  | 
 |     case Promote: | 
 |       switch (Node->getOpcode()) { | 
 |       case ISD::ZERO_EXTEND: | 
 |         Result = PromoteOp(Node->getOperand(0)); | 
 |         // NOTE: Any extend would work here... | 
 |         Result = DAG.getNode(ISD::ZERO_EXTEND, Op.getValueType(), Result); | 
 |         Result = DAG.getZeroExtendInReg(Result, | 
 |                                         Node->getOperand(0).getValueType()); | 
 |         break; | 
 |       case ISD::SIGN_EXTEND: | 
 |         Result = PromoteOp(Node->getOperand(0)); | 
 |         // NOTE: Any extend would work here... | 
 |         Result = DAG.getNode(ISD::ZERO_EXTEND, Op.getValueType(), Result); | 
 |         Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, Result.getValueType(), | 
 |                              Result, Node->getOperand(0).getValueType()); | 
 |         break; | 
 |       case ISD::TRUNCATE: | 
 |         Result = PromoteOp(Node->getOperand(0)); | 
 |         Result = DAG.getNode(ISD::TRUNCATE, Op.getValueType(), Result); | 
 |         break; | 
 |       case ISD::FP_EXTEND: | 
 |         Result = PromoteOp(Node->getOperand(0)); | 
 |         if (Result.getValueType() != Op.getValueType()) | 
 |           // Dynamically dead while we have only 2 FP types. | 
 |           Result = DAG.getNode(ISD::FP_EXTEND, Op.getValueType(), Result); | 
 |         break; | 
 |       case ISD::FP_ROUND: | 
 |       case ISD::FP_TO_SINT: | 
 |       case ISD::FP_TO_UINT: | 
 |         Result = PromoteOp(Node->getOperand(0)); | 
 |         Result = DAG.getNode(Node->getOpcode(), Op.getValueType(), Result); | 
 |         break; | 
 |       case ISD::SINT_TO_FP: | 
 |         Result = PromoteOp(Node->getOperand(0)); | 
 |         Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, Result.getValueType(), | 
 |                              Result, Node->getOperand(0).getValueType()); | 
 |         Result = DAG.getNode(ISD::SINT_TO_FP, Op.getValueType(), Result); | 
 |         break; | 
 |       case ISD::UINT_TO_FP: | 
 |         Result = PromoteOp(Node->getOperand(0)); | 
 |         Result = DAG.getZeroExtendInReg(Result, | 
 |                                         Node->getOperand(0).getValueType()); | 
 |         Result = DAG.getNode(ISD::UINT_TO_FP, Op.getValueType(), Result); | 
 |         break; | 
 |       } | 
 |     } | 
 |     break; | 
 |   case ISD::FP_ROUND_INREG: | 
 |   case ISD::SIGN_EXTEND_INREG: { | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |     MVT::ValueType ExtraVT = cast<MVTSDNode>(Node)->getExtraValueType(); | 
 |  | 
 |     // If this operation is not supported, convert it to a shl/shr or load/store | 
 |     // pair. | 
 |     switch (TLI.getOperationAction(Node->getOpcode(), ExtraVT)) { | 
 |     default: assert(0 && "This action not supported for this op yet!"); | 
 |     case TargetLowering::Legal: | 
 |       if (Tmp1 != Node->getOperand(0)) | 
 |         Result = DAG.getNode(Node->getOpcode(), Node->getValueType(0), Tmp1, | 
 |                              ExtraVT); | 
 |       break; | 
 |     case TargetLowering::Expand: | 
 |       // If this is an integer extend and shifts are supported, do that. | 
 |       if (Node->getOpcode() == ISD::SIGN_EXTEND_INREG) { | 
 |         // NOTE: we could fall back on load/store here too for targets without | 
 |         // SAR.  However, it is doubtful that any exist. | 
 |         unsigned BitsDiff = MVT::getSizeInBits(Node->getValueType(0)) - | 
 |                             MVT::getSizeInBits(ExtraVT); | 
 |         SDOperand ShiftCst = DAG.getConstant(BitsDiff, TLI.getShiftAmountTy()); | 
 |         Result = DAG.getNode(ISD::SHL, Node->getValueType(0), | 
 |                              Node->getOperand(0), ShiftCst); | 
 |         Result = DAG.getNode(ISD::SRA, Node->getValueType(0), | 
 |                              Result, ShiftCst); | 
 |       } else if (Node->getOpcode() == ISD::FP_ROUND_INREG) { | 
 |         // The only way we can lower this is to turn it into a STORETRUNC, | 
 |         // EXTLOAD pair, targetting a temporary location (a stack slot). | 
 |  | 
 |         // NOTE: there is a choice here between constantly creating new stack | 
 |         // slots and always reusing the same one.  We currently always create | 
 |         // new ones, as reuse may inhibit scheduling. | 
 |         const Type *Ty = MVT::getTypeForValueType(ExtraVT); | 
 |         unsigned TySize = (unsigned)TLI.getTargetData().getTypeSize(Ty); | 
 |         unsigned Align  = TLI.getTargetData().getTypeAlignment(Ty); | 
 |         MachineFunction &MF = DAG.getMachineFunction(); | 
 |         int SSFI = | 
 |           MF.getFrameInfo()->CreateStackObject((unsigned)TySize, Align); | 
 |         SDOperand StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy()); | 
 |         Result = DAG.getNode(ISD::TRUNCSTORE, MVT::Other, DAG.getEntryNode(), | 
 |                              Node->getOperand(0), StackSlot, | 
 |                              DAG.getSrcValue(NULL), ExtraVT); | 
 |         Result = DAG.getNode(ISD::EXTLOAD, Node->getValueType(0), | 
 |                              Result, StackSlot, DAG.getSrcValue(NULL), ExtraVT); | 
 |       } else { | 
 |         assert(0 && "Unknown op"); | 
 |       } | 
 |       Result = LegalizeOp(Result); | 
 |       break; | 
 |     } | 
 |     break; | 
 |   } | 
 |   } | 
 |  | 
 |   // Note that LegalizeOp may be reentered even from single-use nodes, which | 
 |   // means that we always must cache transformed nodes. | 
 |   AddLegalizedOperand(Op, Result); | 
 |   return Result; | 
 | } | 
 |  | 
 | /// PromoteOp - Given an operation that produces a value in an invalid type, | 
 | /// promote it to compute the value into a larger type.  The produced value will | 
 | /// have the correct bits for the low portion of the register, but no guarantee | 
 | /// is made about the top bits: it may be zero, sign-extended, or garbage. | 
 | SDOperand SelectionDAGLegalize::PromoteOp(SDOperand Op) { | 
 |   MVT::ValueType VT = Op.getValueType(); | 
 |   MVT::ValueType NVT = TLI.getTypeToTransformTo(VT); | 
 |   assert(getTypeAction(VT) == Promote && | 
 |          "Caller should expand or legalize operands that are not promotable!"); | 
 |   assert(NVT > VT && MVT::isInteger(NVT) == MVT::isInteger(VT) && | 
 |          "Cannot promote to smaller type!"); | 
 |  | 
 |   SDOperand Tmp1, Tmp2, Tmp3; | 
 |  | 
 |   SDOperand Result; | 
 |   SDNode *Node = Op.Val; | 
 |  | 
 |   if (!Node->hasOneUse()) { | 
 |     std::map<SDOperand, SDOperand>::iterator I = PromotedNodes.find(Op); | 
 |     if (I != PromotedNodes.end()) return I->second; | 
 |   } else { | 
 |     assert(!PromotedNodes.count(Op) && "Repromoted this node??"); | 
 |   } | 
 |  | 
 |   // Promotion needs an optimization step to clean up after it, and is not | 
 |   // careful to avoid operations the target does not support.  Make sure that | 
 |   // all generated operations are legalized in the next iteration. | 
 |   NeedsAnotherIteration = true; | 
 |  | 
 |   switch (Node->getOpcode()) { | 
 |   default: | 
 |     std::cerr << "NODE: "; Node->dump(); std::cerr << "\n"; | 
 |     assert(0 && "Do not know how to promote this operator!"); | 
 |     abort(); | 
 |   case ISD::UNDEF: | 
 |     Result = DAG.getNode(ISD::UNDEF, NVT); | 
 |     break; | 
 |   case ISD::Constant: | 
 |     Result = DAG.getNode(ISD::ZERO_EXTEND, NVT, Op); | 
 |     assert(isa<ConstantSDNode>(Result) && "Didn't constant fold zext?"); | 
 |     break; | 
 |   case ISD::ConstantFP: | 
 |     Result = DAG.getNode(ISD::FP_EXTEND, NVT, Op); | 
 |     assert(isa<ConstantFPSDNode>(Result) && "Didn't constant fold fp_extend?"); | 
 |     break; | 
 |   case ISD::CopyFromReg: | 
 |     Result = DAG.getCopyFromReg(cast<RegSDNode>(Node)->getReg(), NVT, | 
 |                                 Node->getOperand(0)); | 
 |     // Remember that we legalized the chain. | 
 |     AddLegalizedOperand(Op.getValue(1), Result.getValue(1)); | 
 |     break; | 
 |  | 
 |   case ISD::SETCC: | 
 |     assert(getTypeAction(TLI.getSetCCResultTy()) == Legal && | 
 |            "SetCC type is not legal??"); | 
 |     Result = DAG.getSetCC(cast<SetCCSDNode>(Node)->getCondition(), | 
 |                           TLI.getSetCCResultTy(), Node->getOperand(0), | 
 |                           Node->getOperand(1)); | 
 |     Result = LegalizeOp(Result); | 
 |     break; | 
 |  | 
 |   case ISD::TRUNCATE: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Legal: | 
 |       Result = LegalizeOp(Node->getOperand(0)); | 
 |       assert(Result.getValueType() >= NVT && | 
 |              "This truncation doesn't make sense!"); | 
 |       if (Result.getValueType() > NVT)    // Truncate to NVT instead of VT | 
 |         Result = DAG.getNode(ISD::TRUNCATE, NVT, Result); | 
 |       break; | 
 |     case Promote: | 
 |       // The truncation is not required, because we don't guarantee anything | 
 |       // about high bits anyway. | 
 |       Result = PromoteOp(Node->getOperand(0)); | 
 |       break; | 
 |     case Expand: | 
 |       ExpandOp(Node->getOperand(0), Tmp1, Tmp2); | 
 |       // Truncate the low part of the expanded value to the result type | 
 |       Result = DAG.getNode(ISD::TRUNCATE, VT, Tmp1); | 
 |     } | 
 |     break; | 
 |   case ISD::SIGN_EXTEND: | 
 |   case ISD::ZERO_EXTEND: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Expand: assert(0 && "BUG: Smaller reg should have been promoted!"); | 
 |     case Legal: | 
 |       // Input is legal?  Just do extend all the way to the larger type. | 
 |       Result = LegalizeOp(Node->getOperand(0)); | 
 |       Result = DAG.getNode(Node->getOpcode(), NVT, Result); | 
 |       break; | 
 |     case Promote: | 
 |       // Promote the reg if it's smaller. | 
 |       Result = PromoteOp(Node->getOperand(0)); | 
 |       // The high bits are not guaranteed to be anything.  Insert an extend. | 
 |       if (Node->getOpcode() == ISD::SIGN_EXTEND) | 
 |         Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Result, | 
 |                              Node->getOperand(0).getValueType()); | 
 |       else | 
 |         Result = DAG.getZeroExtendInReg(Result, | 
 |                                         Node->getOperand(0).getValueType()); | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::FP_EXTEND: | 
 |     assert(0 && "Case not implemented.  Dynamically dead with 2 FP types!"); | 
 |   case ISD::FP_ROUND: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Expand: assert(0 && "BUG: Cannot expand FP regs!"); | 
 |     case Promote:  assert(0 && "Unreachable with 2 FP types!"); | 
 |     case Legal: | 
 |       // Input is legal?  Do an FP_ROUND_INREG. | 
 |       Result = LegalizeOp(Node->getOperand(0)); | 
 |       Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT); | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::SINT_TO_FP: | 
 |   case ISD::UINT_TO_FP: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Legal: | 
 |       Result = LegalizeOp(Node->getOperand(0)); | 
 |       // No extra round required here. | 
 |       Result = DAG.getNode(Node->getOpcode(), NVT, Result); | 
 |       break; | 
 |  | 
 |     case Promote: | 
 |       Result = PromoteOp(Node->getOperand(0)); | 
 |       if (Node->getOpcode() == ISD::SINT_TO_FP) | 
 |         Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, Result.getValueType(), | 
 |                              Result, Node->getOperand(0).getValueType()); | 
 |       else | 
 |         Result = DAG.getZeroExtendInReg(Result, | 
 |                                         Node->getOperand(0).getValueType()); | 
 |       // No extra round required here. | 
 |       Result = DAG.getNode(Node->getOpcode(), NVT, Result); | 
 |       break; | 
 |     case Expand: | 
 |       Result = ExpandIntToFP(Node->getOpcode() == ISD::SINT_TO_FP, NVT, | 
 |                              Node->getOperand(0)); | 
 |       // Round if we cannot tolerate excess precision. | 
 |       if (NoExcessFPPrecision) | 
 |         Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT); | 
 |       break; | 
 |     } | 
 |     break; | 
 |  | 
 |   case ISD::FP_TO_SINT: | 
 |   case ISD::FP_TO_UINT: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Legal: | 
 |       Tmp1 = LegalizeOp(Node->getOperand(0)); | 
 |       break; | 
 |     case Promote: | 
 |       // The input result is prerounded, so we don't have to do anything | 
 |       // special. | 
 |       Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |       break; | 
 |     case Expand: | 
 |       assert(0 && "not implemented"); | 
 |     } | 
 |     Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1); | 
 |     break; | 
 |  | 
 |   case ISD::FABS: | 
 |   case ISD::FNEG: | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     assert(Tmp1.getValueType() == NVT); | 
 |     Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1); | 
 |     // NOTE: we do not have to do any extra rounding here for | 
 |     // NoExcessFPPrecision, because we know the input will have the appropriate | 
 |     // precision, and these operations don't modify precision at all. | 
 |     break; | 
 |  | 
 |   case ISD::FSQRT: | 
 |   case ISD::FSIN: | 
 |   case ISD::FCOS: | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     assert(Tmp1.getValueType() == NVT); | 
 |     Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1); | 
 |     if(NoExcessFPPrecision) | 
 |       Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT); | 
 |     break; | 
 |  | 
 |   case ISD::AND: | 
 |   case ISD::OR: | 
 |   case ISD::XOR: | 
 |   case ISD::ADD: | 
 |   case ISD::SUB: | 
 |   case ISD::MUL: | 
 |     // The input may have strange things in the top bits of the registers, but | 
 |     // these operations don't care.  They may have wierd bits going out, but | 
 |     // that too is okay if they are integer operations. | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     Tmp2 = PromoteOp(Node->getOperand(1)); | 
 |     assert(Tmp1.getValueType() == NVT && Tmp2.getValueType() == NVT); | 
 |     Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1, Tmp2); | 
 |  | 
 |     // However, if this is a floating point operation, they will give excess | 
 |     // precision that we may not be able to tolerate.  If we DO allow excess | 
 |     // precision, just leave it, otherwise excise it. | 
 |     // FIXME: Why would we need to round FP ops more than integer ones? | 
 |     //     Is Round(Add(Add(A,B),C)) != Round(Add(Round(Add(A,B)), C)) | 
 |     if (MVT::isFloatingPoint(NVT) && NoExcessFPPrecision) | 
 |       Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT); | 
 |     break; | 
 |  | 
 |   case ISD::SDIV: | 
 |   case ISD::SREM: | 
 |     // These operators require that their input be sign extended. | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     Tmp2 = PromoteOp(Node->getOperand(1)); | 
 |     if (MVT::isInteger(NVT)) { | 
 |       Tmp1 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp1, VT); | 
 |       Tmp2 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp2, VT); | 
 |     } | 
 |     Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1, Tmp2); | 
 |  | 
 |     // Perform FP_ROUND: this is probably overly pessimistic. | 
 |     if (MVT::isFloatingPoint(NVT) && NoExcessFPPrecision) | 
 |       Result = DAG.getNode(ISD::FP_ROUND_INREG, NVT, Result, VT); | 
 |     break; | 
 |  | 
 |   case ISD::UDIV: | 
 |   case ISD::UREM: | 
 |     // These operators require that their input be zero extended. | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     Tmp2 = PromoteOp(Node->getOperand(1)); | 
 |     assert(MVT::isInteger(NVT) && "Operators don't apply to FP!"); | 
 |     Tmp1 = DAG.getZeroExtendInReg(Tmp1, VT); | 
 |     Tmp2 = DAG.getZeroExtendInReg(Tmp2, VT); | 
 |     Result = DAG.getNode(Node->getOpcode(), NVT, Tmp1, Tmp2); | 
 |     break; | 
 |  | 
 |   case ISD::SHL: | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |     Result = DAG.getNode(ISD::SHL, NVT, Tmp1, Tmp2); | 
 |     break; | 
 |   case ISD::SRA: | 
 |     // The input value must be properly sign extended. | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     Tmp1 = DAG.getNode(ISD::SIGN_EXTEND_INREG, NVT, Tmp1, VT); | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |     Result = DAG.getNode(ISD::SRA, NVT, Tmp1, Tmp2); | 
 |     break; | 
 |   case ISD::SRL: | 
 |     // The input value must be properly zero extended. | 
 |     Tmp1 = PromoteOp(Node->getOperand(0)); | 
 |     Tmp1 = DAG.getZeroExtendInReg(Tmp1, VT); | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1)); | 
 |     Result = DAG.getNode(ISD::SRL, NVT, Tmp1, Tmp2); | 
 |     break; | 
 |   case ISD::LOAD: | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));   // Legalize the chain. | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));   // Legalize the pointer. | 
 |     // FIXME: When the DAG combiner exists, change this to use EXTLOAD! | 
 |     if (MVT::isInteger(NVT)) | 
 |       Result = DAG.getNode(ISD::ZEXTLOAD, NVT, Tmp1, Tmp2, Node->getOperand(2), | 
 |                            VT); | 
 |     else | 
 |       Result = DAG.getNode(ISD::EXTLOAD, NVT, Tmp1, Tmp2, Node->getOperand(2), | 
 |                            VT); | 
 |  | 
 |     // Remember that we legalized the chain. | 
 |     AddLegalizedOperand(Op.getValue(1), Result.getValue(1)); | 
 |     break; | 
 |   case ISD::SELECT: | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Expand: assert(0 && "It's impossible to expand bools"); | 
 |     case Legal: | 
 |       Tmp1 = LegalizeOp(Node->getOperand(0));// Legalize the condition. | 
 |       break; | 
 |     case Promote: | 
 |       Tmp1 = PromoteOp(Node->getOperand(0)); // Promote the condition. | 
 |       break; | 
 |     } | 
 |     Tmp2 = PromoteOp(Node->getOperand(1));   // Legalize the op0 | 
 |     Tmp3 = PromoteOp(Node->getOperand(2));   // Legalize the op1 | 
 |     Result = DAG.getNode(ISD::SELECT, NVT, Tmp1, Tmp2, Tmp3); | 
 |     break; | 
 |   case ISD::CALL: { | 
 |     Tmp1 = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     Tmp2 = LegalizeOp(Node->getOperand(1));  // Legalize the callee. | 
 |  | 
 |     std::vector<SDOperand> Ops; | 
 |     for (unsigned i = 2, e = Node->getNumOperands(); i != e; ++i) | 
 |       Ops.push_back(LegalizeOp(Node->getOperand(i))); | 
 |  | 
 |     assert(Node->getNumValues() == 2 && Op.ResNo == 0 && | 
 |            "Can only promote single result calls"); | 
 |     std::vector<MVT::ValueType> RetTyVTs; | 
 |     RetTyVTs.reserve(2); | 
 |     RetTyVTs.push_back(NVT); | 
 |     RetTyVTs.push_back(MVT::Other); | 
 |     SDNode *NC = DAG.getCall(RetTyVTs, Tmp1, Tmp2, Ops); | 
 |     Result = SDOperand(NC, 0); | 
 |  | 
 |     // Insert the new chain mapping. | 
 |     AddLegalizedOperand(Op.getValue(1), Result.getValue(1)); | 
 |     break; | 
 |   } | 
 |   case ISD::CTPOP: | 
 |   case ISD::CTTZ: | 
 |   case ISD::CTLZ: | 
 |     Tmp1 = Node->getOperand(0); | 
 |     //Zero extend the argument | 
 |     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, NVT, Tmp1); | 
 |     // Perform the larger operation, then subtract if needed. | 
 |     Tmp1 = DAG.getNode(Node->getOpcode(), NVT, Tmp1); | 
 |     switch(Node->getOpcode()) | 
 |     { | 
 |     case ISD::CTPOP: | 
 |       Result = Tmp1; | 
 |       break; | 
 |     case ISD::CTTZ: | 
 |       //if Tmp1 == sizeinbits(NVT) then Tmp1 = sizeinbits(Old VT) | 
 |       Tmp2 = DAG.getSetCC(ISD::SETEQ, MVT::i1, Tmp1,  | 
 |                           DAG.getConstant(getSizeInBits(NVT), NVT)); | 
 |       Result = DAG.getNode(ISD::SELECT, NVT, Tmp2,  | 
 |                            DAG.getConstant(getSizeInBits(VT),NVT), Tmp1); | 
 |       break; | 
 |     case ISD::CTLZ: | 
 |       //Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT)) | 
 |       Result = DAG.getNode(ISD::SUB, NVT, Tmp1,  | 
 |                            DAG.getConstant(getSizeInBits(NVT) -  | 
 |                                            getSizeInBits(VT), NVT)); | 
 |       break; | 
 |     } | 
 |     break; | 
 |   } | 
 |  | 
 |   assert(Result.Val && "Didn't set a result!"); | 
 |   AddPromotedOperand(Op, Result); | 
 |   return Result; | 
 | } | 
 |  | 
 | /// ExpandAddSub - Find a clever way to expand this add operation into | 
 | /// subcomponents. | 
 | void SelectionDAGLegalize:: | 
 | ExpandByParts(unsigned NodeOp, SDOperand LHS, SDOperand RHS, | 
 |               SDOperand &Lo, SDOperand &Hi) { | 
 |   // Expand the subcomponents. | 
 |   SDOperand LHSL, LHSH, RHSL, RHSH; | 
 |   ExpandOp(LHS, LHSL, LHSH); | 
 |   ExpandOp(RHS, RHSL, RHSH); | 
 |  | 
 |   // FIXME: this should be moved to the dag combiner someday. | 
 |   if (NodeOp == ISD::ADD_PARTS || NodeOp == ISD::SUB_PARTS) | 
 |     if (LHSL.getValueType() == MVT::i32) { | 
 |       SDOperand LowEl; | 
 |       if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(LHSL)) | 
 |         if (C->getValue() == 0) | 
 |           LowEl = RHSL; | 
 |       if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHSL)) | 
 |         if (C->getValue() == 0) | 
 |           LowEl = LHSL; | 
 |       if (LowEl.Val) { | 
 |         // Turn this into an add/sub of the high part only. | 
 |         SDOperand HiEl = | 
 |           DAG.getNode(NodeOp == ISD::ADD_PARTS ? ISD::ADD : ISD::SUB, | 
 |                       LowEl.getValueType(), LHSH, RHSH); | 
 |         Lo = LowEl; | 
 |         Hi = HiEl; | 
 |         return; | 
 |       } | 
 |     } | 
 |  | 
 |   std::vector<SDOperand> Ops; | 
 |   Ops.push_back(LHSL); | 
 |   Ops.push_back(LHSH); | 
 |   Ops.push_back(RHSL); | 
 |   Ops.push_back(RHSH); | 
 |   Lo = DAG.getNode(NodeOp, LHSL.getValueType(), Ops); | 
 |   Hi = Lo.getValue(1); | 
 | } | 
 |  | 
 | void SelectionDAGLegalize::ExpandShiftParts(unsigned NodeOp, | 
 |                                             SDOperand Op, SDOperand Amt, | 
 |                                             SDOperand &Lo, SDOperand &Hi) { | 
 |   // Expand the subcomponents. | 
 |   SDOperand LHSL, LHSH; | 
 |   ExpandOp(Op, LHSL, LHSH); | 
 |  | 
 |   std::vector<SDOperand> Ops; | 
 |   Ops.push_back(LHSL); | 
 |   Ops.push_back(LHSH); | 
 |   Ops.push_back(Amt); | 
 |   Lo = DAG.getNode(NodeOp, LHSL.getValueType(), Ops); | 
 |   Hi = Lo.getValue(1); | 
 | } | 
 |  | 
 |  | 
 | /// ExpandShift - Try to find a clever way to expand this shift operation out to | 
 | /// smaller elements.  If we can't find a way that is more efficient than a | 
 | /// libcall on this target, return false.  Otherwise, return true with the | 
 | /// low-parts expanded into Lo and Hi. | 
 | bool SelectionDAGLegalize::ExpandShift(unsigned Opc, SDOperand Op,SDOperand Amt, | 
 |                                        SDOperand &Lo, SDOperand &Hi) { | 
 |   assert((Opc == ISD::SHL || Opc == ISD::SRA || Opc == ISD::SRL) && | 
 |          "This is not a shift!"); | 
 |  | 
 |   MVT::ValueType NVT = TLI.getTypeToTransformTo(Op.getValueType()); | 
 |   SDOperand ShAmt = LegalizeOp(Amt); | 
 |   MVT::ValueType ShTy = ShAmt.getValueType(); | 
 |   unsigned VTBits = MVT::getSizeInBits(Op.getValueType()); | 
 |   unsigned NVTBits = MVT::getSizeInBits(NVT); | 
 |  | 
 |   // Handle the case when Amt is an immediate.  Other cases are currently broken | 
 |   // and are disabled. | 
 |   if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Amt.Val)) { | 
 |     unsigned Cst = CN->getValue(); | 
 |     // Expand the incoming operand to be shifted, so that we have its parts | 
 |     SDOperand InL, InH; | 
 |     ExpandOp(Op, InL, InH); | 
 |     switch(Opc) { | 
 |     case ISD::SHL: | 
 |       if (Cst > VTBits) { | 
 |         Lo = DAG.getConstant(0, NVT); | 
 |         Hi = DAG.getConstant(0, NVT); | 
 |       } else if (Cst > NVTBits) { | 
 |         Lo = DAG.getConstant(0, NVT); | 
 |         Hi = DAG.getNode(ISD::SHL, NVT, InL, DAG.getConstant(Cst-NVTBits,ShTy)); | 
 |       } else if (Cst == NVTBits) { | 
 |         Lo = DAG.getConstant(0, NVT); | 
 |         Hi = InL; | 
 |       } else { | 
 |         Lo = DAG.getNode(ISD::SHL, NVT, InL, DAG.getConstant(Cst, ShTy)); | 
 |         Hi = DAG.getNode(ISD::OR, NVT, | 
 |            DAG.getNode(ISD::SHL, NVT, InH, DAG.getConstant(Cst, ShTy)), | 
 |            DAG.getNode(ISD::SRL, NVT, InL, DAG.getConstant(NVTBits-Cst, ShTy))); | 
 |       } | 
 |       return true; | 
 |     case ISD::SRL: | 
 |       if (Cst > VTBits) { | 
 |         Lo = DAG.getConstant(0, NVT); | 
 |         Hi = DAG.getConstant(0, NVT); | 
 |       } else if (Cst > NVTBits) { | 
 |         Lo = DAG.getNode(ISD::SRL, NVT, InH, DAG.getConstant(Cst-NVTBits,ShTy)); | 
 |         Hi = DAG.getConstant(0, NVT); | 
 |       } else if (Cst == NVTBits) { | 
 |         Lo = InH; | 
 |         Hi = DAG.getConstant(0, NVT); | 
 |       } else { | 
 |         Lo = DAG.getNode(ISD::OR, NVT, | 
 |            DAG.getNode(ISD::SRL, NVT, InL, DAG.getConstant(Cst, ShTy)), | 
 |            DAG.getNode(ISD::SHL, NVT, InH, DAG.getConstant(NVTBits-Cst, ShTy))); | 
 |         Hi = DAG.getNode(ISD::SRL, NVT, InH, DAG.getConstant(Cst, ShTy)); | 
 |       } | 
 |       return true; | 
 |     case ISD::SRA: | 
 |       if (Cst > VTBits) { | 
 |         Hi = Lo = DAG.getNode(ISD::SRA, NVT, InH, | 
 |                               DAG.getConstant(NVTBits-1, ShTy)); | 
 |       } else if (Cst > NVTBits) { | 
 |         Lo = DAG.getNode(ISD::SRA, NVT, InH, | 
 |                            DAG.getConstant(Cst-NVTBits, ShTy)); | 
 |         Hi = DAG.getNode(ISD::SRA, NVT, InH, | 
 |                               DAG.getConstant(NVTBits-1, ShTy)); | 
 |       } else if (Cst == NVTBits) { | 
 |         Lo = InH; | 
 |         Hi = DAG.getNode(ISD::SRA, NVT, InH, | 
 |                               DAG.getConstant(NVTBits-1, ShTy)); | 
 |       } else { | 
 |         Lo = DAG.getNode(ISD::OR, NVT, | 
 |            DAG.getNode(ISD::SRL, NVT, InL, DAG.getConstant(Cst, ShTy)), | 
 |            DAG.getNode(ISD::SHL, NVT, InH, DAG.getConstant(NVTBits-Cst, ShTy))); | 
 |         Hi = DAG.getNode(ISD::SRA, NVT, InH, DAG.getConstant(Cst, ShTy)); | 
 |       } | 
 |       return true; | 
 |     } | 
 |   } | 
 |   // FIXME: The following code for expanding shifts using ISD::SELECT is buggy, | 
 |   // so disable it for now.  Currently targets are handling this via SHL_PARTS | 
 |   // and friends. | 
 |   return false; | 
 |  | 
 |   // If we have an efficient select operation (or if the selects will all fold | 
 |   // away), lower to some complex code, otherwise just emit the libcall. | 
 |   if (TLI.getOperationAction(ISD::SELECT, NVT) != TargetLowering::Legal && | 
 |       !isa<ConstantSDNode>(Amt)) | 
 |     return false; | 
 |  | 
 |   SDOperand InL, InH; | 
 |   ExpandOp(Op, InL, InH); | 
 |   SDOperand NAmt = DAG.getNode(ISD::SUB, ShTy,           // NAmt = 32-ShAmt | 
 |                                DAG.getConstant(NVTBits, ShTy), ShAmt); | 
 |  | 
 |   // Compare the unmasked shift amount against 32. | 
 |   SDOperand Cond = DAG.getSetCC(ISD::SETGE, TLI.getSetCCResultTy(), ShAmt, | 
 |                                 DAG.getConstant(NVTBits, ShTy)); | 
 |  | 
 |   if (TLI.getShiftAmountFlavor() != TargetLowering::Mask) { | 
 |     ShAmt = DAG.getNode(ISD::AND, ShTy, ShAmt,             // ShAmt &= 31 | 
 |                         DAG.getConstant(NVTBits-1, ShTy)); | 
 |     NAmt  = DAG.getNode(ISD::AND, ShTy, NAmt,              // NAmt &= 31 | 
 |                         DAG.getConstant(NVTBits-1, ShTy)); | 
 |   } | 
 |  | 
 |   if (Opc == ISD::SHL) { | 
 |     SDOperand T1 = DAG.getNode(ISD::OR, NVT,// T1 = (Hi << Amt) | (Lo >> NAmt) | 
 |                                DAG.getNode(ISD::SHL, NVT, InH, ShAmt), | 
 |                                DAG.getNode(ISD::SRL, NVT, InL, NAmt)); | 
 |     SDOperand T2 = DAG.getNode(ISD::SHL, NVT, InL, ShAmt); // T2 = Lo << Amt&31 | 
 |  | 
 |     Hi = DAG.getNode(ISD::SELECT, NVT, Cond, T2, T1); | 
 |     Lo = DAG.getNode(ISD::SELECT, NVT, Cond, DAG.getConstant(0, NVT), T2); | 
 |   } else { | 
 |     SDOperand HiLoPart = DAG.getNode(ISD::SELECT, NVT, | 
 |                                      DAG.getSetCC(ISD::SETEQ, | 
 |                                                   TLI.getSetCCResultTy(), NAmt, | 
 |                                                   DAG.getConstant(32, ShTy)), | 
 |                                      DAG.getConstant(0, NVT), | 
 |                                      DAG.getNode(ISD::SHL, NVT, InH, NAmt)); | 
 |     SDOperand T1 = DAG.getNode(ISD::OR, NVT,// T1 = (Hi << NAmt) | (Lo >> Amt) | 
 |                                HiLoPart, | 
 |                                DAG.getNode(ISD::SRL, NVT, InL, ShAmt)); | 
 |     SDOperand T2 = DAG.getNode(Opc, NVT, InH, ShAmt);  // T2 = InH >> ShAmt&31 | 
 |  | 
 |     SDOperand HiPart; | 
 |     if (Opc == ISD::SRA) | 
 |       HiPart = DAG.getNode(ISD::SRA, NVT, InH, | 
 |                            DAG.getConstant(NVTBits-1, ShTy)); | 
 |     else | 
 |       HiPart = DAG.getConstant(0, NVT); | 
 |     Lo = DAG.getNode(ISD::SELECT, NVT, Cond, T2, T1); | 
 |     Hi = DAG.getNode(ISD::SELECT, NVT, Cond, HiPart, T2); | 
 |   } | 
 |   return true; | 
 | } | 
 |  | 
 | /// FindLatestCallSeqStart - Scan up the dag to find the latest (highest | 
 | /// NodeDepth) node that is an CallSeqStart operation and occurs later than | 
 | /// Found. | 
 | static void FindLatestCallSeqStart(SDNode *Node, SDNode *&Found) { | 
 |   if (Node->getNodeDepth() <= Found->getNodeDepth()) return; | 
 |  | 
 |   // If we found an CALLSEQ_START, we already know this node occurs later | 
 |   // than the Found node. Just remember this node and return. | 
 |   if (Node->getOpcode() == ISD::CALLSEQ_START) { | 
 |     Found = Node; | 
 |     return; | 
 |   } | 
 |  | 
 |   // Otherwise, scan the operands of Node to see if any of them is a call. | 
 |   assert(Node->getNumOperands() != 0 && | 
 |          "All leaves should have depth equal to the entry node!"); | 
 |   for (unsigned i = 0, e = Node->getNumOperands()-1; i != e; ++i) | 
 |     FindLatestCallSeqStart(Node->getOperand(i).Val, Found); | 
 |  | 
 |   // Tail recurse for the last iteration. | 
 |   FindLatestCallSeqStart(Node->getOperand(Node->getNumOperands()-1).Val, | 
 |                              Found); | 
 | } | 
 |  | 
 |  | 
 | /// FindEarliestCallSeqEnd - Scan down the dag to find the earliest (lowest | 
 | /// NodeDepth) node that is an CallSeqEnd operation and occurs more recent | 
 | /// than Found. | 
 | static void FindEarliestCallSeqEnd(SDNode *Node, SDNode *&Found) { | 
 |   if (Found && Node->getNodeDepth() >= Found->getNodeDepth()) return; | 
 |  | 
 |   // If we found an CALLSEQ_END, we already know this node occurs earlier | 
 |   // than the Found node. Just remember this node and return. | 
 |   if (Node->getOpcode() == ISD::CALLSEQ_END) { | 
 |     Found = Node; | 
 |     return; | 
 |   } | 
 |  | 
 |   // Otherwise, scan the operands of Node to see if any of them is a call. | 
 |   SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end(); | 
 |   if (UI == E) return; | 
 |   for (--E; UI != E; ++UI) | 
 |     FindEarliestCallSeqEnd(*UI, Found); | 
 |  | 
 |   // Tail recurse for the last iteration. | 
 |   FindEarliestCallSeqEnd(*UI, Found); | 
 | } | 
 |  | 
 | /// FindCallSeqEnd - Given a chained node that is part of a call sequence, | 
 | /// find the CALLSEQ_END node that terminates the call sequence. | 
 | static SDNode *FindCallSeqEnd(SDNode *Node) { | 
 |   if (Node->getOpcode() == ISD::CALLSEQ_END) | 
 |     return Node; | 
 |   if (Node->use_empty()) | 
 |     return 0;   // No CallSeqEnd | 
 |  | 
 |   if (Node->hasOneUse())  // Simple case, only has one user to check. | 
 |     return FindCallSeqEnd(*Node->use_begin()); | 
 |  | 
 |   SDOperand TheChain(Node, Node->getNumValues()-1); | 
 |   assert(TheChain.getValueType() == MVT::Other && "Is not a token chain!"); | 
 |  | 
 |   for (SDNode::use_iterator UI = Node->use_begin(), | 
 |          E = Node->use_end(); ; ++UI) { | 
 |     assert(UI != E && "Didn't find a user of the tokchain, no CALLSEQ_END!"); | 
 |  | 
 |     // Make sure to only follow users of our token chain. | 
 |     SDNode *User = *UI; | 
 |     for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) | 
 |       if (User->getOperand(i) == TheChain) | 
 |         return FindCallSeqEnd(User); | 
 |   } | 
 |   assert(0 && "Unreachable"); | 
 |   abort(); | 
 | } | 
 |  | 
 | /// FindCallSeqStart - Given a chained node that is part of a call sequence, | 
 | /// find the CALLSEQ_START node that initiates the call sequence. | 
 | static SDNode *FindCallSeqStart(SDNode *Node) { | 
 |   assert(Node && "Didn't find callseq_start for a call??"); | 
 |   if (Node->getOpcode() == ISD::CALLSEQ_START) return Node; | 
 |  | 
 |   assert(Node->getOperand(0).getValueType() == MVT::Other && | 
 |          "Node doesn't have a token chain argument!"); | 
 |   return FindCallSeqStart(Node->getOperand(0).Val); | 
 | } | 
 |  | 
 |  | 
 | /// FindInputOutputChains - If we are replacing an operation with a call we need | 
 | /// to find the call that occurs before and the call that occurs after it to | 
 | /// properly serialize the calls in the block.  The returned operand is the | 
 | /// input chain value for the new call (e.g. the entry node or the previous | 
 | /// call), and OutChain is set to be the chain node to update to point to the | 
 | /// end of the call chain. | 
 | static SDOperand FindInputOutputChains(SDNode *OpNode, SDNode *&OutChain, | 
 |                                        SDOperand Entry) { | 
 |   SDNode *LatestCallSeqStart = Entry.Val; | 
 |   SDNode *LatestCallSeqEnd = 0; | 
 |   FindLatestCallSeqStart(OpNode, LatestCallSeqStart); | 
 |   //std::cerr<<"Found node: "; LatestCallSeqStart->dump(); std::cerr <<"\n"; | 
 |  | 
 |   // It is possible that no ISD::CALLSEQ_START was found because there is no | 
 |   // previous call in the function.  LatestCallStackDown may in that case be | 
 |   // the entry node itself.  Do not attempt to find a matching CALLSEQ_END | 
 |   // unless LatestCallStackDown is an CALLSEQ_START. | 
 |   if (LatestCallSeqStart->getOpcode() == ISD::CALLSEQ_START) | 
 |     LatestCallSeqEnd = FindCallSeqEnd(LatestCallSeqStart); | 
 |   else | 
 |     LatestCallSeqEnd = Entry.Val; | 
 |   assert(LatestCallSeqEnd && "NULL return from FindCallSeqEnd"); | 
 |  | 
 |   // Finally, find the first call that this must come before, first we find the | 
 |   // CallSeqEnd that ends the call. | 
 |   OutChain = 0; | 
 |   FindEarliestCallSeqEnd(OpNode, OutChain); | 
 |  | 
 |   // If we found one, translate from the adj up to the callseq_start. | 
 |   if (OutChain) | 
 |     OutChain = FindCallSeqStart(OutChain); | 
 |  | 
 |   return SDOperand(LatestCallSeqEnd, 0); | 
 | } | 
 |  | 
 | /// SpliceCallInto - Given the result chain of a libcall (CallResult), and a  | 
 | void SelectionDAGLegalize::SpliceCallInto(const SDOperand &CallResult, | 
 |                                           SDNode *OutChain) { | 
 |   // Nothing to splice it into? | 
 |   if (OutChain == 0) return; | 
 |  | 
 |   assert(OutChain->getOperand(0).getValueType() == MVT::Other); | 
 |   //OutChain->dump(); | 
 |  | 
 |   // Form a token factor node merging the old inval and the new inval. | 
 |   SDOperand InToken = DAG.getNode(ISD::TokenFactor, MVT::Other, CallResult, | 
 |                                   OutChain->getOperand(0)); | 
 |   // Change the node to refer to the new token. | 
 |   OutChain->setAdjCallChain(InToken); | 
 | } | 
 |  | 
 |  | 
 | // ExpandLibCall - Expand a node into a call to a libcall.  If the result value | 
 | // does not fit into a register, return the lo part and set the hi part to the | 
 | // by-reg argument.  If it does fit into a single register, return the result | 
 | // and leave the Hi part unset. | 
 | SDOperand SelectionDAGLegalize::ExpandLibCall(const char *Name, SDNode *Node, | 
 |                                               SDOperand &Hi) { | 
 |   SDNode *OutChain; | 
 |   SDOperand InChain = FindInputOutputChains(Node, OutChain, | 
 |                                             DAG.getEntryNode()); | 
 |   if (InChain.Val == 0) | 
 |     InChain = DAG.getEntryNode(); | 
 |  | 
 |   TargetLowering::ArgListTy Args; | 
 |   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) { | 
 |     MVT::ValueType ArgVT = Node->getOperand(i).getValueType(); | 
 |     const Type *ArgTy = MVT::getTypeForValueType(ArgVT); | 
 |     Args.push_back(std::make_pair(Node->getOperand(i), ArgTy)); | 
 |   } | 
 |   SDOperand Callee = DAG.getExternalSymbol(Name, TLI.getPointerTy()); | 
 |  | 
 |   // Splice the libcall in wherever FindInputOutputChains tells us to. | 
 |   const Type *RetTy = MVT::getTypeForValueType(Node->getValueType(0)); | 
 |   std::pair<SDOperand,SDOperand> CallInfo = | 
 |     TLI.LowerCallTo(InChain, RetTy, false, 0, Callee, Args, DAG); | 
 |   SpliceCallInto(CallInfo.second, OutChain); | 
 |  | 
 |   NeedsAnotherIteration = true; | 
 |  | 
 |   switch (getTypeAction(CallInfo.first.getValueType())) { | 
 |   default: assert(0 && "Unknown thing"); | 
 |   case Legal: | 
 |     return CallInfo.first; | 
 |   case Promote: | 
 |     assert(0 && "Cannot promote this yet!"); | 
 |   case Expand: | 
 |     SDOperand Lo; | 
 |     ExpandOp(CallInfo.first, Lo, Hi); | 
 |     return Lo; | 
 |   } | 
 | } | 
 |  | 
 |  | 
 | /// ExpandIntToFP - Expand a [US]INT_TO_FP operation, assuming that the | 
 | /// destination type is legal. | 
 | SDOperand SelectionDAGLegalize:: | 
 | ExpandIntToFP(bool isSigned, MVT::ValueType DestTy, SDOperand Source) { | 
 |   assert(getTypeAction(DestTy) == Legal && "Destination type is not legal!"); | 
 |   assert(getTypeAction(Source.getValueType()) == Expand && | 
 |          "This is not an expansion!"); | 
 |   assert(Source.getValueType() == MVT::i64 && "Only handle expand from i64!"); | 
 |  | 
 |   if (!isSigned) { | 
 |     assert(Source.getValueType() == MVT::i64 && | 
 |            "This only works for 64-bit -> FP"); | 
 |     // The 64-bit value loaded will be incorrectly if the 'sign bit' of the | 
 |     // incoming integer is set.  To handle this, we dynamically test to see if | 
 |     // it is set, and, if so, add a fudge factor. | 
 |     SDOperand Lo, Hi; | 
 |     ExpandOp(Source, Lo, Hi); | 
 |  | 
 |     // If this is unsigned, and not supported, first perform the conversion to | 
 |     // signed, then adjust the result if the sign bit is set. | 
 |     SDOperand SignedConv = ExpandIntToFP(true, DestTy, | 
 |                    DAG.getNode(ISD::BUILD_PAIR, Source.getValueType(), Lo, Hi)); | 
 |  | 
 |     SDOperand SignSet = DAG.getSetCC(ISD::SETLT, TLI.getSetCCResultTy(), Hi, | 
 |                                      DAG.getConstant(0, Hi.getValueType())); | 
 |     SDOperand Zero = getIntPtrConstant(0), Four = getIntPtrConstant(4); | 
 |     SDOperand CstOffset = DAG.getNode(ISD::SELECT, Zero.getValueType(), | 
 |                                       SignSet, Four, Zero); | 
 |     uint64_t FF = 0x5f800000ULL; | 
 |     if (TLI.isLittleEndian()) FF <<= 32; | 
 |     static Constant *FudgeFactor = ConstantUInt::get(Type::ULongTy, FF); | 
 |  | 
 |     MachineConstantPool *CP = DAG.getMachineFunction().getConstantPool(); | 
 |     SDOperand CPIdx = DAG.getConstantPool(CP->getConstantPoolIndex(FudgeFactor), | 
 |                                           TLI.getPointerTy()); | 
 |     CPIdx = DAG.getNode(ISD::ADD, TLI.getPointerTy(), CPIdx, CstOffset); | 
 |     SDOperand FudgeInReg; | 
 |     if (DestTy == MVT::f32) | 
 |       FudgeInReg = DAG.getLoad(MVT::f32, DAG.getEntryNode(), CPIdx, | 
 |                                DAG.getSrcValue(NULL)); | 
 |     else { | 
 |       assert(DestTy == MVT::f64 && "Unexpected conversion"); | 
 |       FudgeInReg = DAG.getNode(ISD::EXTLOAD, MVT::f64, DAG.getEntryNode(), | 
 |                                CPIdx, DAG.getSrcValue(NULL), MVT::f32); | 
 |     } | 
 |     return DAG.getNode(ISD::ADD, DestTy, SignedConv, FudgeInReg); | 
 |   } | 
 |  | 
 |   // Expand the source, then glue it back together for the call.  We must expand | 
 |   // the source in case it is shared (this pass of legalize must traverse it). | 
 |   SDOperand SrcLo, SrcHi; | 
 |   ExpandOp(Source, SrcLo, SrcHi); | 
 |   Source = DAG.getNode(ISD::BUILD_PAIR, Source.getValueType(), SrcLo, SrcHi); | 
 |  | 
 |   SDNode *OutChain = 0; | 
 |   SDOperand InChain = FindInputOutputChains(Source.Val, OutChain, | 
 |                                             DAG.getEntryNode()); | 
 |   const char *FnName = 0; | 
 |   if (DestTy == MVT::f32) | 
 |     FnName = "__floatdisf"; | 
 |   else { | 
 |     assert(DestTy == MVT::f64 && "Unknown fp value type!"); | 
 |     FnName = "__floatdidf"; | 
 |   } | 
 |  | 
 |   SDOperand Callee = DAG.getExternalSymbol(FnName, TLI.getPointerTy()); | 
 |  | 
 |   TargetLowering::ArgListTy Args; | 
 |   const Type *ArgTy = MVT::getTypeForValueType(Source.getValueType()); | 
 |  | 
 |   Args.push_back(std::make_pair(Source, ArgTy)); | 
 |  | 
 |   // We don't care about token chains for libcalls.  We just use the entry | 
 |   // node as our input and ignore the output chain.  This allows us to place | 
 |   // calls wherever we need them to satisfy data dependences. | 
 |   const Type *RetTy = MVT::getTypeForValueType(DestTy); | 
 |  | 
 |   std::pair<SDOperand,SDOperand> CallResult = | 
 |     TLI.LowerCallTo(InChain, RetTy, false, 0, Callee, Args, DAG); | 
 |  | 
 |   SpliceCallInto(CallResult.second, OutChain); | 
 |   return CallResult.first; | 
 | } | 
 |  | 
 |  | 
 |  | 
 | /// ExpandOp - Expand the specified SDOperand into its two component pieces | 
 | /// Lo&Hi.  Note that the Op MUST be an expanded type.  As a result of this, the | 
 | /// LegalizeNodes map is filled in for any results that are not expanded, the | 
 | /// ExpandedNodes map is filled in for any results that are expanded, and the | 
 | /// Lo/Hi values are returned. | 
 | void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){ | 
 |   MVT::ValueType VT = Op.getValueType(); | 
 |   MVT::ValueType NVT = TLI.getTypeToTransformTo(VT); | 
 |   SDNode *Node = Op.Val; | 
 |   assert(getTypeAction(VT) == Expand && "Not an expanded type!"); | 
 |   assert(MVT::isInteger(VT) && "Cannot expand FP values!"); | 
 |   assert(MVT::isInteger(NVT) && NVT < VT && | 
 |          "Cannot expand to FP value or to larger int value!"); | 
 |  | 
 |   // If there is more than one use of this, see if we already expanded it. | 
 |   // There is no use remembering values that only have a single use, as the map | 
 |   // entries will never be reused. | 
 |   if (!Node->hasOneUse()) { | 
 |     std::map<SDOperand, std::pair<SDOperand, SDOperand> >::iterator I | 
 |       = ExpandedNodes.find(Op); | 
 |     if (I != ExpandedNodes.end()) { | 
 |       Lo = I->second.first; | 
 |       Hi = I->second.second; | 
 |       return; | 
 |     } | 
 |   } else { | 
 |     assert(!ExpandedNodes.count(Op) && "Re-expanding a node!"); | 
 |   } | 
 |  | 
 |   // Expanding to multiple registers needs to perform an optimization step, and | 
 |   // is not careful to avoid operations the target does not support.  Make sure | 
 |   // that all generated operations are legalized in the next iteration. | 
 |   NeedsAnotherIteration = true; | 
 |  | 
 |   switch (Node->getOpcode()) { | 
 |   default: | 
 |     std::cerr << "NODE: "; Node->dump(); std::cerr << "\n"; | 
 |     assert(0 && "Do not know how to expand this operator!"); | 
 |     abort(); | 
 |   case ISD::UNDEF: | 
 |     Lo = DAG.getNode(ISD::UNDEF, NVT); | 
 |     Hi = DAG.getNode(ISD::UNDEF, NVT); | 
 |     break; | 
 |   case ISD::Constant: { | 
 |     uint64_t Cst = cast<ConstantSDNode>(Node)->getValue(); | 
 |     Lo = DAG.getConstant(Cst, NVT); | 
 |     Hi = DAG.getConstant(Cst >> MVT::getSizeInBits(NVT), NVT); | 
 |     break; | 
 |   } | 
 |  | 
 |   case ISD::CopyFromReg: { | 
 |     unsigned Reg = cast<RegSDNode>(Node)->getReg(); | 
 |     // Aggregate register values are always in consequtive pairs. | 
 |     Lo = DAG.getCopyFromReg(Reg, NVT, Node->getOperand(0)); | 
 |     Hi = DAG.getCopyFromReg(Reg+1, NVT, Lo.getValue(1)); | 
 |  | 
 |     // Remember that we legalized the chain. | 
 |     AddLegalizedOperand(Op.getValue(1), Hi.getValue(1)); | 
 |  | 
 |     assert(isTypeLegal(NVT) && "Cannot expand this multiple times yet!"); | 
 |     break; | 
 |   } | 
 |  | 
 |   case ISD::BUILD_PAIR: | 
 |     // Legalize both operands.  FIXME: in the future we should handle the case | 
 |     // where the two elements are not legal. | 
 |     assert(isTypeLegal(NVT) && "Cannot expand this multiple times yet!"); | 
 |     Lo = LegalizeOp(Node->getOperand(0)); | 
 |     Hi = LegalizeOp(Node->getOperand(1)); | 
 |     break; | 
 |  | 
 |   case ISD::CTPOP: | 
 |     ExpandOp(Node->getOperand(0), Lo, Hi); | 
 |     Lo = DAG.getNode(ISD::ADD, NVT,          // ctpop(HL) -> ctpop(H)+ctpop(L) | 
 |                      DAG.getNode(ISD::CTPOP, NVT, Lo), | 
 |                      DAG.getNode(ISD::CTPOP, NVT, Hi)); | 
 |     Hi = DAG.getConstant(0, NVT); | 
 |     break; | 
 |  | 
 |   case ISD::CTLZ: { | 
 |     // ctlz (HL) -> ctlz(H) != 32 ? ctlz(H) : (ctlz(L)+32) | 
 |     ExpandOp(Node->getOperand(0), Lo, Hi); | 
 |     SDOperand BitsC = DAG.getConstant(MVT::getSizeInBits(NVT), NVT); | 
 |     SDOperand HLZ = DAG.getNode(ISD::CTLZ, NVT, Hi); | 
 |     SDOperand TopNotZero = DAG.getSetCC(ISD::SETNE, TLI.getSetCCResultTy(), | 
 |                                         HLZ, BitsC); | 
 |     SDOperand LowPart = DAG.getNode(ISD::CTLZ, NVT, Lo); | 
 |     LowPart = DAG.getNode(ISD::ADD, NVT, LowPart, BitsC); | 
 |  | 
 |     Lo = DAG.getNode(ISD::SELECT, NVT, TopNotZero, HLZ, LowPart); | 
 |     Hi = DAG.getConstant(0, NVT); | 
 |     break; | 
 |   } | 
 |  | 
 |   case ISD::CTTZ: { | 
 |     // cttz (HL) -> cttz(L) != 32 ? cttz(L) : (cttz(H)+32) | 
 |     ExpandOp(Node->getOperand(0), Lo, Hi); | 
 |     SDOperand BitsC = DAG.getConstant(MVT::getSizeInBits(NVT), NVT); | 
 |     SDOperand LTZ = DAG.getNode(ISD::CTTZ, NVT, Lo); | 
 |     SDOperand BotNotZero = DAG.getSetCC(ISD::SETNE, TLI.getSetCCResultTy(), | 
 |                                         LTZ, BitsC); | 
 |     SDOperand HiPart = DAG.getNode(ISD::CTTZ, NVT, Hi); | 
 |     HiPart = DAG.getNode(ISD::ADD, NVT, HiPart, BitsC); | 
 |  | 
 |     Lo = DAG.getNode(ISD::SELECT, NVT, BotNotZero, LTZ, HiPart); | 
 |     Hi = DAG.getConstant(0, NVT); | 
 |     break; | 
 |   } | 
 |  | 
 |   case ISD::LOAD: { | 
 |     SDOperand Ch = LegalizeOp(Node->getOperand(0));   // Legalize the chain. | 
 |     SDOperand Ptr = LegalizeOp(Node->getOperand(1));  // Legalize the pointer. | 
 |     Lo = DAG.getLoad(NVT, Ch, Ptr, Node->getOperand(2)); | 
 |  | 
 |     // Increment the pointer to the other half. | 
 |     unsigned IncrementSize = MVT::getSizeInBits(Lo.getValueType())/8; | 
 |     Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr, | 
 |                       getIntPtrConstant(IncrementSize)); | 
 |     //Is this safe?  declaring that the two parts of the split load   | 
 |     //are from the same instruction? | 
 |     Hi = DAG.getLoad(NVT, Ch, Ptr, Node->getOperand(2)); | 
 |  | 
 |     // Build a factor node to remember that this load is independent of the | 
 |     // other one. | 
 |     SDOperand TF = DAG.getNode(ISD::TokenFactor, MVT::Other, Lo.getValue(1), | 
 |                                Hi.getValue(1)); | 
 |  | 
 |     // Remember that we legalized the chain. | 
 |     AddLegalizedOperand(Op.getValue(1), TF); | 
 |     if (!TLI.isLittleEndian()) | 
 |       std::swap(Lo, Hi); | 
 |     break; | 
 |   } | 
 |   case ISD::CALL: { | 
 |     SDOperand Chain  = LegalizeOp(Node->getOperand(0));  // Legalize the chain. | 
 |     SDOperand Callee = LegalizeOp(Node->getOperand(1));  // Legalize the callee. | 
 |  | 
 |     bool Changed = false; | 
 |     std::vector<SDOperand> Ops; | 
 |     for (unsigned i = 2, e = Node->getNumOperands(); i != e; ++i) { | 
 |       Ops.push_back(LegalizeOp(Node->getOperand(i))); | 
 |       Changed |= Ops.back() != Node->getOperand(i); | 
 |     } | 
 |  | 
 |     assert(Node->getNumValues() == 2 && Op.ResNo == 0 && | 
 |            "Can only expand a call once so far, not i64 -> i16!"); | 
 |  | 
 |     std::vector<MVT::ValueType> RetTyVTs; | 
 |     RetTyVTs.reserve(3); | 
 |     RetTyVTs.push_back(NVT); | 
 |     RetTyVTs.push_back(NVT); | 
 |     RetTyVTs.push_back(MVT::Other); | 
 |     SDNode *NC = DAG.getCall(RetTyVTs, Chain, Callee, Ops); | 
 |     Lo = SDOperand(NC, 0); | 
 |     Hi = SDOperand(NC, 1); | 
 |  | 
 |     // Insert the new chain mapping. | 
 |     AddLegalizedOperand(Op.getValue(1), Hi.getValue(2)); | 
 |     break; | 
 |   } | 
 |   case ISD::AND: | 
 |   case ISD::OR: | 
 |   case ISD::XOR: {   // Simple logical operators -> two trivial pieces. | 
 |     SDOperand LL, LH, RL, RH; | 
 |     ExpandOp(Node->getOperand(0), LL, LH); | 
 |     ExpandOp(Node->getOperand(1), RL, RH); | 
 |     Lo = DAG.getNode(Node->getOpcode(), NVT, LL, RL); | 
 |     Hi = DAG.getNode(Node->getOpcode(), NVT, LH, RH); | 
 |     break; | 
 |   } | 
 |   case ISD::SELECT: { | 
 |     SDOperand C, LL, LH, RL, RH; | 
 |  | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Expand: assert(0 && "It's impossible to expand bools"); | 
 |     case Legal: | 
 |       C = LegalizeOp(Node->getOperand(0)); // Legalize the condition. | 
 |       break; | 
 |     case Promote: | 
 |       C = PromoteOp(Node->getOperand(0));  // Promote the condition. | 
 |       break; | 
 |     } | 
 |     ExpandOp(Node->getOperand(1), LL, LH); | 
 |     ExpandOp(Node->getOperand(2), RL, RH); | 
 |     Lo = DAG.getNode(ISD::SELECT, NVT, C, LL, RL); | 
 |     Hi = DAG.getNode(ISD::SELECT, NVT, C, LH, RH); | 
 |     break; | 
 |   } | 
 |   case ISD::SIGN_EXTEND: { | 
 |     SDOperand In; | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Expand: assert(0 && "expand-expand not implemented yet!"); | 
 |     case Legal: In = LegalizeOp(Node->getOperand(0)); break; | 
 |     case Promote: | 
 |       In = PromoteOp(Node->getOperand(0)); | 
 |       // Emit the appropriate sign_extend_inreg to get the value we want. | 
 |       In = DAG.getNode(ISD::SIGN_EXTEND_INREG, In.getValueType(), In, | 
 |                        Node->getOperand(0).getValueType()); | 
 |       break; | 
 |     } | 
 |  | 
 |     // The low part is just a sign extension of the input (which degenerates to | 
 |     // a copy). | 
 |     Lo = DAG.getNode(ISD::SIGN_EXTEND, NVT, In); | 
 |  | 
 |     // The high part is obtained by SRA'ing all but one of the bits of the lo | 
 |     // part. | 
 |     unsigned LoSize = MVT::getSizeInBits(Lo.getValueType()); | 
 |     Hi = DAG.getNode(ISD::SRA, NVT, Lo, DAG.getConstant(LoSize-1, | 
 |                                                        TLI.getShiftAmountTy())); | 
 |     break; | 
 |   } | 
 |   case ISD::ZERO_EXTEND: { | 
 |     SDOperand In; | 
 |     switch (getTypeAction(Node->getOperand(0).getValueType())) { | 
 |     case Expand: assert(0 && "expand-expand not implemented yet!"); | 
 |     case Legal: In = LegalizeOp(Node->getOperand(0)); break; | 
 |     case Promote: | 
 |       In = PromoteOp(Node->getOperand(0)); | 
 |       // Emit the appropriate zero_extend_inreg to get the value we want. | 
 |       In = DAG.getZeroExtendInReg(In, Node->getOperand(0).getValueType()); | 
 |       break; | 
 |     } | 
 |  | 
 |     // The low part is just a zero extension of the input (which degenerates to | 
 |     // a copy). | 
 |     Lo = DAG.getNode(ISD::ZERO_EXTEND, NVT, In); | 
 |  | 
 |     // The high part is just a zero. | 
 |     Hi = DAG.getConstant(0, NVT); | 
 |     break; | 
 |   } | 
 |     // These operators cannot be expanded directly, emit them as calls to | 
 |     // library functions. | 
 |   case ISD::FP_TO_SINT: | 
 |     if (Node->getOperand(0).getValueType() == MVT::f32) | 
 |       Lo = ExpandLibCall("__fixsfdi", Node, Hi); | 
 |     else | 
 |       Lo = ExpandLibCall("__fixdfdi", Node, Hi); | 
 |     break; | 
 |   case ISD::FP_TO_UINT: | 
 |     if (Node->getOperand(0).getValueType() == MVT::f32) | 
 |       Lo = ExpandLibCall("__fixunssfdi", Node, Hi); | 
 |     else | 
 |       Lo = ExpandLibCall("__fixunsdfdi", Node, Hi); | 
 |     break; | 
 |  | 
 |   case ISD::SHL: | 
 |     // If we can emit an efficient shift operation, do so now. | 
 |     if (ExpandShift(ISD::SHL, Node->getOperand(0), Node->getOperand(1), Lo, Hi)) | 
 |       break; | 
 |  | 
 |     // If this target supports SHL_PARTS, use it. | 
 |     if (TLI.getOperationAction(ISD::SHL_PARTS, NVT) == TargetLowering::Legal) { | 
 |       ExpandShiftParts(ISD::SHL_PARTS, Node->getOperand(0), Node->getOperand(1), | 
 |                        Lo, Hi); | 
 |       break; | 
 |     } | 
 |  | 
 |     // Otherwise, emit a libcall. | 
 |     Lo = ExpandLibCall("__ashldi3", Node, Hi); | 
 |     break; | 
 |  | 
 |   case ISD::SRA: | 
 |     // If we can emit an efficient shift operation, do so now. | 
 |     if (ExpandShift(ISD::SRA, Node->getOperand(0), Node->getOperand(1), Lo, Hi)) | 
 |       break; | 
 |  | 
 |     // If this target supports SRA_PARTS, use it. | 
 |     if (TLI.getOperationAction(ISD::SRA_PARTS, NVT) == TargetLowering::Legal) { | 
 |       ExpandShiftParts(ISD::SRA_PARTS, Node->getOperand(0), Node->getOperand(1), | 
 |                        Lo, Hi); | 
 |       break; | 
 |     } | 
 |  | 
 |     // Otherwise, emit a libcall. | 
 |     Lo = ExpandLibCall("__ashrdi3", Node, Hi); | 
 |     break; | 
 |   case ISD::SRL: | 
 |     // If we can emit an efficient shift operation, do so now. | 
 |     if (ExpandShift(ISD::SRL, Node->getOperand(0), Node->getOperand(1), Lo, Hi)) | 
 |       break; | 
 |  | 
 |     // If this target supports SRL_PARTS, use it. | 
 |     if (TLI.getOperationAction(ISD::SRL_PARTS, NVT) == TargetLowering::Legal) { | 
 |       ExpandShiftParts(ISD::SRL_PARTS, Node->getOperand(0), Node->getOperand(1), | 
 |                        Lo, Hi); | 
 |       break; | 
 |     } | 
 |  | 
 |     // Otherwise, emit a libcall. | 
 |     Lo = ExpandLibCall("__lshrdi3", Node, Hi); | 
 |     break; | 
 |  | 
 |   case ISD::ADD: | 
 |     ExpandByParts(ISD::ADD_PARTS, Node->getOperand(0), Node->getOperand(1), | 
 |                   Lo, Hi); | 
 |     break; | 
 |   case ISD::SUB: | 
 |     ExpandByParts(ISD::SUB_PARTS, Node->getOperand(0), Node->getOperand(1), | 
 |                   Lo, Hi); | 
 |     break; | 
 |   case ISD::MUL: { | 
 |     if (TLI.getOperationAction(ISD::MULHU, NVT) == TargetLowering::Legal) { | 
 |       SDOperand LL, LH, RL, RH; | 
 |       ExpandOp(Node->getOperand(0), LL, LH); | 
 |       ExpandOp(Node->getOperand(1), RL, RH); | 
 |       Hi = DAG.getNode(ISD::MULHU, NVT, LL, RL); | 
 |       RH = DAG.getNode(ISD::MUL, NVT, LL, RH); | 
 |       LH = DAG.getNode(ISD::MUL, NVT, LH, RL); | 
 |       Hi = DAG.getNode(ISD::ADD, NVT, Hi, RH); | 
 |       Hi = DAG.getNode(ISD::ADD, NVT, Hi, LH); | 
 |       Lo = DAG.getNode(ISD::MUL, NVT, LL, RL); | 
 |     } else { | 
 |       Lo = ExpandLibCall("__muldi3" , Node, Hi); break; | 
 |     } | 
 |     break; | 
 |   } | 
 |   case ISD::SDIV: Lo = ExpandLibCall("__divdi3" , Node, Hi); break; | 
 |   case ISD::UDIV: Lo = ExpandLibCall("__udivdi3", Node, Hi); break; | 
 |   case ISD::SREM: Lo = ExpandLibCall("__moddi3" , Node, Hi); break; | 
 |   case ISD::UREM: Lo = ExpandLibCall("__umoddi3", Node, Hi); break; | 
 |   } | 
 |  | 
 |   // Remember in a map if the values will be reused later. | 
 |   if (!Node->hasOneUse()) { | 
 |     bool isNew = ExpandedNodes.insert(std::make_pair(Op, | 
 |                                             std::make_pair(Lo, Hi))).second; | 
 |     assert(isNew && "Value already expanded?!?"); | 
 |   } | 
 | } | 
 |  | 
 |  | 
 | // SelectionDAG::Legalize - This is the entry point for the file. | 
 | // | 
 | void SelectionDAG::Legalize() { | 
 |   /// run - This is the main entry point to this class. | 
 |   /// | 
 |   SelectionDAGLegalize(*this).Run(); | 
 | } | 
 |  |