| //===-- X86ISelPattern.cpp - A pattern matching inst selector for X86 -----===// | 
 | // | 
 | //                     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 defines a pattern matching instruction selector for X86. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | #include "X86.h" | 
 | #include "X86InstrBuilder.h" | 
 | #include "X86RegisterInfo.h" | 
 | #include "llvm/Constants.h" | 
 | #include "llvm/Instructions.h" | 
 | #include "llvm/Function.h" | 
 | #include "llvm/CodeGen/MachineConstantPool.h" | 
 | #include "llvm/CodeGen/MachineFunction.h" | 
 | #include "llvm/CodeGen/MachineFrameInfo.h" | 
 | #include "llvm/CodeGen/SelectionDAG.h" | 
 | #include "llvm/CodeGen/SelectionDAGISel.h" | 
 | #include "llvm/CodeGen/SSARegMap.h" | 
 | #include "llvm/Target/TargetData.h" | 
 | #include "llvm/Target/TargetLowering.h" | 
 | #include "llvm/Target/TargetOptions.h" | 
 | #include "llvm/Support/CFG.h" | 
 | #include "llvm/Support/MathExtras.h" | 
 | #include "llvm/ADT/Statistic.h" | 
 | #include <set> | 
 | #include <algorithm> | 
 | using namespace llvm; | 
 |  | 
 | //===----------------------------------------------------------------------===// | 
 | //  X86TargetLowering - X86 Implementation of the TargetLowering interface | 
 | namespace { | 
 |   class X86TargetLowering : public TargetLowering { | 
 |     int VarArgsFrameIndex;            // FrameIndex for start of varargs area. | 
 |     int ReturnAddrIndex;              // FrameIndex for return slot. | 
 |   public: | 
 |     X86TargetLowering(TargetMachine &TM) : TargetLowering(TM) { | 
 |       // Set up the TargetLowering object. | 
 |  | 
 |       // X86 is wierd, it always uses i8 for shift amounts and setcc results. | 
 |       setShiftAmountType(MVT::i8); | 
 |       setSetCCResultType(MVT::i8); | 
 |       setSetCCResultContents(ZeroOrOneSetCCResult); | 
 |       setShiftAmountFlavor(Mask);   // shl X, 32 == shl X, 0 | 
 |  | 
 |       // Set up the register classes. | 
 |       addRegisterClass(MVT::i8, X86::R8RegisterClass); | 
 |       addRegisterClass(MVT::i16, X86::R16RegisterClass); | 
 |       addRegisterClass(MVT::i32, X86::R32RegisterClass); | 
 |       addRegisterClass(MVT::f64, X86::RFPRegisterClass); | 
 |  | 
 |       // FIXME: Eliminate these two classes when legalize can handle promotions | 
 |       // well. | 
 | /**/  addRegisterClass(MVT::i1, X86::R8RegisterClass); | 
 |  | 
 |       setOperationAction(ISD::BRCONDTWOWAY     , MVT::Other, Expand); | 
 |       setOperationAction(ISD::MEMMOVE          , MVT::Other, Expand); | 
 |       setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16  , Expand); | 
 |       setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1   , Expand); | 
 |       setOperationAction(ISD::FP_ROUND_INREG   , MVT::f32  , Expand); | 
 |       setOperationAction(ISD::SEXTLOAD         , MVT::i1   , Expand); | 
 |       setOperationAction(ISD::SREM             , MVT::f64  , Expand); | 
 |       setOperationAction(ISD::CTPOP            , MVT::i32  , Expand); | 
 |       setOperationAction(ISD::CTTZ             , MVT::i32  , Expand); | 
 |       setOperationAction(ISD::CTLZ             , MVT::i32  , Expand); | 
 |  | 
 |       setOperationAction(ISD::READIO           , MVT::i1   , Expand); | 
 |       setOperationAction(ISD::READIO           , MVT::i8   , Expand); | 
 |       setOperationAction(ISD::READIO           , MVT::i16  , Expand); | 
 |       setOperationAction(ISD::READIO           , MVT::i32  , Expand); | 
 |       setOperationAction(ISD::WRITEIO          , MVT::i1   , Expand); | 
 |       setOperationAction(ISD::WRITEIO          , MVT::i8   , Expand); | 
 |       setOperationAction(ISD::WRITEIO          , MVT::i16  , Expand); | 
 |       setOperationAction(ISD::WRITEIO          , MVT::i32  , Expand); | 
 |  | 
 |       if (!UnsafeFPMath) { | 
 |         setOperationAction(ISD::FSIN           , MVT::f64  , Expand); | 
 |         setOperationAction(ISD::FCOS           , MVT::f64  , Expand); | 
 |       } | 
 |  | 
 |       // These should be promoted to a larger select which is supported. | 
 | /**/  setOperationAction(ISD::SELECT           , MVT::i1   , Promote); | 
 |       setOperationAction(ISD::SELECT           , MVT::i8   , Promote); | 
 |  | 
 |       computeRegisterProperties(); | 
 |  | 
 |       addLegalFPImmediate(+0.0); // FLD0 | 
 |       addLegalFPImmediate(+1.0); // FLD1 | 
 |       addLegalFPImmediate(-0.0); // FLD0/FCHS | 
 |       addLegalFPImmediate(-1.0); // FLD1/FCHS | 
 |     } | 
 |  | 
 |     /// LowerArguments - This hook must be implemented to indicate how we should | 
 |     /// lower the arguments for the specified function, into the specified DAG. | 
 |     virtual std::vector<SDOperand> | 
 |     LowerArguments(Function &F, SelectionDAG &DAG); | 
 |  | 
 |     /// LowerCallTo - This hook lowers an abstract call to a function into an | 
 |     /// actual call. | 
 |     virtual std::pair<SDOperand, SDOperand> | 
 |     LowerCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg, | 
 |                 SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG); | 
 |  | 
 |     virtual std::pair<SDOperand, SDOperand> | 
 |     LowerVAStart(SDOperand Chain, SelectionDAG &DAG); | 
 |  | 
 |     virtual std::pair<SDOperand,SDOperand> | 
 |     LowerVAArgNext(bool isVANext, SDOperand Chain, SDOperand VAList, | 
 |                    const Type *ArgTy, SelectionDAG &DAG); | 
 |  | 
 |     virtual std::pair<SDOperand, SDOperand> | 
 |     LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth, | 
 |                             SelectionDAG &DAG); | 
 |   }; | 
 | } | 
 |  | 
 |  | 
 | std::vector<SDOperand> | 
 | X86TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) { | 
 |   std::vector<SDOperand> ArgValues; | 
 |  | 
 |   // Add DAG nodes to load the arguments...  On entry to a function on the X86, | 
 |   // the stack frame looks like this: | 
 |   // | 
 |   // [ESP] -- return address | 
 |   // [ESP + 4] -- first argument (leftmost lexically) | 
 |   // [ESP + 8] -- second argument, if first argument is four bytes in size | 
 |   //    ... | 
 |   // | 
 |   MachineFunction &MF = DAG.getMachineFunction(); | 
 |   MachineFrameInfo *MFI = MF.getFrameInfo(); | 
 |  | 
 |   unsigned ArgOffset = 0;   // Frame mechanisms handle retaddr slot | 
 |   for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) { | 
 |     MVT::ValueType ObjectVT = getValueType(I->getType()); | 
 |     unsigned ArgIncrement = 4; | 
 |     unsigned ObjSize; | 
 |     switch (ObjectVT) { | 
 |     default: assert(0 && "Unhandled argument type!"); | 
 |     case MVT::i1: | 
 |     case MVT::i8:  ObjSize = 1;                break; | 
 |     case MVT::i16: ObjSize = 2;                break; | 
 |     case MVT::i32: ObjSize = 4;                break; | 
 |     case MVT::i64: ObjSize = ArgIncrement = 8; break; | 
 |     case MVT::f32: ObjSize = 4;                break; | 
 |     case MVT::f64: ObjSize = ArgIncrement = 8; break; | 
 |     } | 
 |     // Create the frame index object for this incoming parameter... | 
 |     int FI = MFI->CreateFixedObject(ObjSize, ArgOffset); | 
 |  | 
 |     // Create the SelectionDAG nodes corresponding to a load from this parameter | 
 |     SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32); | 
 |  | 
 |     // Don't codegen dead arguments.  FIXME: remove this check when we can nuke | 
 |     // dead loads. | 
 |     SDOperand ArgValue; | 
 |     if (!I->use_empty()) | 
 |       ArgValue = DAG.getLoad(ObjectVT, DAG.getEntryNode(), FIN, | 
 |                              DAG.getSrcValue(NULL)); | 
 |     else { | 
 |       if (MVT::isInteger(ObjectVT)) | 
 |         ArgValue = DAG.getConstant(0, ObjectVT); | 
 |       else | 
 |         ArgValue = DAG.getConstantFP(0, ObjectVT); | 
 |     } | 
 |     ArgValues.push_back(ArgValue); | 
 |  | 
 |     ArgOffset += ArgIncrement;   // Move on to the next argument... | 
 |   } | 
 |  | 
 |   // If the function takes variable number of arguments, make a frame index for | 
 |   // the start of the first vararg value... for expansion of llvm.va_start. | 
 |   if (F.isVarArg()) | 
 |     VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset); | 
 |   ReturnAddrIndex = 0;  // No return address slot generated yet. | 
 |  | 
 |   // Finally, inform the code generator which regs we return values in. | 
 |   switch (getValueType(F.getReturnType())) { | 
 |   default: assert(0 && "Unknown type!"); | 
 |   case MVT::isVoid: break; | 
 |   case MVT::i1: | 
 |   case MVT::i8: | 
 |   case MVT::i16: | 
 |   case MVT::i32: | 
 |     MF.addLiveOut(X86::EAX); | 
 |     break; | 
 |   case MVT::i64: | 
 |     MF.addLiveOut(X86::EAX); | 
 |     MF.addLiveOut(X86::EDX); | 
 |     break; | 
 |   case MVT::f32: | 
 |   case MVT::f64: | 
 |     MF.addLiveOut(X86::ST0); | 
 |     break; | 
 |   } | 
 |   return ArgValues; | 
 | } | 
 |  | 
 | std::pair<SDOperand, SDOperand> | 
 | X86TargetLowering::LowerCallTo(SDOperand Chain, | 
 | 				 const Type *RetTy, bool isVarArg, | 
 |          SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG) { | 
 |   // Count how many bytes are to be pushed on the stack. | 
 |   unsigned NumBytes = 0; | 
 |  | 
 |   if (Args.empty()) { | 
 |     // Save zero bytes. | 
 |     Chain = DAG.getNode(ISD::ADJCALLSTACKDOWN, MVT::Other, Chain, | 
 |                         DAG.getConstant(0, getPointerTy())); | 
 |   } else { | 
 |     for (unsigned i = 0, e = Args.size(); i != e; ++i) | 
 |       switch (getValueType(Args[i].second)) { | 
 |       default: assert(0 && "Unknown value type!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8: | 
 |       case MVT::i16: | 
 |       case MVT::i32: | 
 |       case MVT::f32: | 
 |         NumBytes += 4; | 
 |         break; | 
 |       case MVT::i64: | 
 |       case MVT::f64: | 
 |         NumBytes += 8; | 
 |         break; | 
 |       } | 
 |  | 
 |     Chain = DAG.getNode(ISD::ADJCALLSTACKDOWN, MVT::Other, Chain, | 
 |                         DAG.getConstant(NumBytes, getPointerTy())); | 
 |  | 
 |     // Arguments go on the stack in reverse order, as specified by the ABI. | 
 |     unsigned ArgOffset = 0; | 
 |     SDOperand StackPtr = DAG.getCopyFromReg(X86::ESP, MVT::i32, | 
 |                                             DAG.getEntryNode()); | 
 |     std::vector<SDOperand> Stores; | 
 |  | 
 |     for (unsigned i = 0, e = Args.size(); i != e; ++i) { | 
 |       SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy()); | 
 |       PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff); | 
 |  | 
 |       switch (getValueType(Args[i].second)) { | 
 |       default: assert(0 && "Unexpected ValueType for argument!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8: | 
 |       case MVT::i16: | 
 |         // Promote the integer to 32 bits.  If the input type is signed use a | 
 |         // sign extend, otherwise use a zero extend. | 
 |         if (Args[i].second->isSigned()) | 
 |           Args[i].first =DAG.getNode(ISD::SIGN_EXTEND, MVT::i32, Args[i].first); | 
 |         else | 
 |           Args[i].first =DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Args[i].first); | 
 |  | 
 |         // FALL THROUGH | 
 |       case MVT::i32: | 
 |       case MVT::f32: | 
 |         Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain, | 
 |                                      Args[i].first, PtrOff, | 
 |                                      DAG.getSrcValue(NULL))); | 
 |         ArgOffset += 4; | 
 |         break; | 
 |       case MVT::i64: | 
 |       case MVT::f64: | 
 |         Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain, | 
 |                                      Args[i].first, PtrOff, | 
 |                                      DAG.getSrcValue(NULL))); | 
 |         ArgOffset += 8; | 
 |         break; | 
 |       } | 
 |     } | 
 |     Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Stores); | 
 |   } | 
 |  | 
 |   std::vector<MVT::ValueType> RetVals; | 
 |   MVT::ValueType RetTyVT = getValueType(RetTy); | 
 |   if (RetTyVT != MVT::isVoid) | 
 |     RetVals.push_back(RetTyVT); | 
 |   RetVals.push_back(MVT::Other); | 
 |  | 
 |   SDOperand TheCall = SDOperand(DAG.getCall(RetVals, Chain, Callee), 0); | 
 |   Chain = TheCall.getValue(RetTyVT != MVT::isVoid); | 
 |   Chain = DAG.getNode(ISD::ADJCALLSTACKUP, MVT::Other, Chain, | 
 |                       DAG.getConstant(NumBytes, getPointerTy())); | 
 |   return std::make_pair(TheCall, Chain); | 
 | } | 
 |  | 
 | std::pair<SDOperand, SDOperand> | 
 | X86TargetLowering::LowerVAStart(SDOperand Chain, SelectionDAG &DAG) { | 
 |   // vastart just returns the address of the VarArgsFrameIndex slot. | 
 |   return std::make_pair(DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32), Chain); | 
 | } | 
 |  | 
 | std::pair<SDOperand,SDOperand> X86TargetLowering:: | 
 | LowerVAArgNext(bool isVANext, SDOperand Chain, SDOperand VAList, | 
 |                const Type *ArgTy, SelectionDAG &DAG) { | 
 |   MVT::ValueType ArgVT = getValueType(ArgTy); | 
 |   SDOperand Result; | 
 |   if (!isVANext) { | 
 |     Result = DAG.getLoad(ArgVT, DAG.getEntryNode(), VAList, | 
 |                          DAG.getSrcValue(NULL)); | 
 |   } else { | 
 |     unsigned Amt; | 
 |     if (ArgVT == MVT::i32) | 
 |       Amt = 4; | 
 |     else { | 
 |       assert((ArgVT == MVT::i64 || ArgVT == MVT::f64) && | 
 |              "Other types should have been promoted for varargs!"); | 
 |       Amt = 8; | 
 |     } | 
 |     Result = DAG.getNode(ISD::ADD, VAList.getValueType(), VAList, | 
 |                          DAG.getConstant(Amt, VAList.getValueType())); | 
 |   } | 
 |   return std::make_pair(Result, Chain); | 
 | } | 
 |  | 
 |  | 
 | std::pair<SDOperand, SDOperand> X86TargetLowering:: | 
 | LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth, | 
 |                         SelectionDAG &DAG) { | 
 |   SDOperand Result; | 
 |   if (Depth)        // Depths > 0 not supported yet! | 
 |     Result = DAG.getConstant(0, getPointerTy()); | 
 |   else { | 
 |     if (ReturnAddrIndex == 0) { | 
 |       // Set up a frame object for the return address. | 
 |       MachineFunction &MF = DAG.getMachineFunction(); | 
 |       ReturnAddrIndex = MF.getFrameInfo()->CreateFixedObject(4, -4); | 
 |     } | 
 |  | 
 |     SDOperand RetAddrFI = DAG.getFrameIndex(ReturnAddrIndex, MVT::i32); | 
 |  | 
 |     if (!isFrameAddress) | 
 |       // Just load the return address | 
 |       Result = DAG.getLoad(MVT::i32, DAG.getEntryNode(), RetAddrFI, DAG.getSrcValue(NULL)); | 
 |     else | 
 |       Result = DAG.getNode(ISD::SUB, MVT::i32, RetAddrFI, | 
 |                            DAG.getConstant(4, MVT::i32)); | 
 |   } | 
 |   return std::make_pair(Result, Chain); | 
 | } | 
 |  | 
 |  | 
 | namespace { | 
 |   /// X86ISelAddressMode - This corresponds to X86AddressMode, but uses | 
 |   /// SDOperand's instead of register numbers for the leaves of the matched | 
 |   /// tree. | 
 |   struct X86ISelAddressMode { | 
 |     enum { | 
 |       RegBase, | 
 |       FrameIndexBase, | 
 |     } BaseType; | 
 |  | 
 |     struct {            // This is really a union, discriminated by BaseType! | 
 |       SDOperand Reg; | 
 |       int FrameIndex; | 
 |     } Base; | 
 |  | 
 |     unsigned Scale; | 
 |     SDOperand IndexReg; | 
 |     unsigned Disp; | 
 |     GlobalValue *GV; | 
 |  | 
 |     X86ISelAddressMode() | 
 |       : BaseType(RegBase), Scale(1), IndexReg(), Disp(), GV(0) { | 
 |     } | 
 |   }; | 
 | } | 
 |  | 
 |  | 
 | namespace { | 
 |   Statistic<> | 
 |   NumFPKill("x86-codegen", "Number of FP_REG_KILL instructions added"); | 
 |  | 
 |   //===--------------------------------------------------------------------===// | 
 |   /// ISel - X86 specific code to select X86 machine instructions for | 
 |   /// SelectionDAG operations. | 
 |   /// | 
 |   class ISel : public SelectionDAGISel { | 
 |     /// ContainsFPCode - Every instruction we select that uses or defines a FP | 
 |     /// register should set this to true. | 
 |     bool ContainsFPCode; | 
 |  | 
 |     /// X86Lowering - This object fully describes how to lower LLVM code to an | 
 |     /// X86-specific SelectionDAG. | 
 |     X86TargetLowering X86Lowering; | 
 |  | 
 |     /// RegPressureMap - This keeps an approximate count of the number of | 
 |     /// registers required to evaluate each node in the graph. | 
 |     std::map<SDNode*, unsigned> RegPressureMap; | 
 |  | 
 |     /// ExprMap - As shared expressions are codegen'd, we keep track of which | 
 |     /// vreg the value is produced in, so we only emit one copy of each compiled | 
 |     /// tree. | 
 |     std::map<SDOperand, unsigned> ExprMap; | 
 |  | 
 |   public: | 
 |     ISel(TargetMachine &TM) : SelectionDAGISel(X86Lowering), X86Lowering(TM) { | 
 |     } | 
 |  | 
 |     virtual const char *getPassName() const { | 
 |       return "X86 Pattern Instruction Selection"; | 
 |     } | 
 |  | 
 |     unsigned getRegPressure(SDOperand O) { | 
 |       return RegPressureMap[O.Val]; | 
 |     } | 
 |     unsigned ComputeRegPressure(SDOperand O); | 
 |  | 
 |     /// InstructionSelectBasicBlock - This callback is invoked by | 
 |     /// SelectionDAGISel when it has created a SelectionDAG for us to codegen. | 
 |     virtual void InstructionSelectBasicBlock(SelectionDAG &DAG); | 
 |  | 
 |     bool isFoldableLoad(SDOperand Op, SDOperand OtherOp, | 
 |                         bool FloatPromoteOk = false); | 
 |     void EmitFoldedLoad(SDOperand Op, X86AddressMode &AM); | 
 |     bool TryToFoldLoadOpStore(SDNode *Node); | 
 |  | 
 |     bool EmitOrOpOp(SDOperand Op1, SDOperand Op2, unsigned DestReg); | 
 |     void EmitCMP(SDOperand LHS, SDOperand RHS, bool isOnlyUse); | 
 |     bool EmitBranchCC(MachineBasicBlock *Dest, SDOperand Chain, SDOperand Cond); | 
 |     void EmitSelectCC(SDOperand Cond, MVT::ValueType SVT, | 
 |                       unsigned RTrue, unsigned RFalse, unsigned RDest); | 
 |     unsigned SelectExpr(SDOperand N); | 
 |  | 
 |     X86AddressMode SelectAddrExprs(const X86ISelAddressMode &IAM); | 
 |     bool MatchAddress(SDOperand N, X86ISelAddressMode &AM); | 
 |     void SelectAddress(SDOperand N, X86AddressMode &AM); | 
 |     void Select(SDOperand N); | 
 |   }; | 
 | } | 
 |  | 
 | /// InstructionSelectBasicBlock - This callback is invoked by SelectionDAGISel | 
 | /// when it has created a SelectionDAG for us to codegen. | 
 | void ISel::InstructionSelectBasicBlock(SelectionDAG &DAG) { | 
 |   // While we're doing this, keep track of whether we see any FP code for | 
 |   // FP_REG_KILL insertion. | 
 |   ContainsFPCode = false; | 
 |  | 
 |   // Scan the PHI nodes that already are inserted into this basic block.  If any | 
 |   // of them is a PHI of a floating point value, we need to insert an | 
 |   // FP_REG_KILL. | 
 |   SSARegMap *RegMap = BB->getParent()->getSSARegMap(); | 
 |   for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); | 
 |        I != E; ++I) { | 
 |     assert(I->getOpcode() == X86::PHI && | 
 |            "Isn't just PHI nodes?"); | 
 |     if (RegMap->getRegClass(I->getOperand(0).getReg()) == | 
 |         X86::RFPRegisterClass) { | 
 |       ContainsFPCode = true; | 
 |       break; | 
 |     } | 
 |   } | 
 |  | 
 |   // Compute the RegPressureMap, which is an approximation for the number of | 
 |   // registers required to compute each node. | 
 |   ComputeRegPressure(DAG.getRoot()); | 
 |  | 
 |   // Codegen the basic block. | 
 |   Select(DAG.getRoot()); | 
 |  | 
 |   // Finally, look at all of the successors of this block.  If any contain a PHI | 
 |   // node of FP type, we need to insert an FP_REG_KILL in this block. | 
 |   for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(), | 
 |          E = BB->succ_end(); SI != E && !ContainsFPCode; ++SI) | 
 |     for (MachineBasicBlock::iterator I = (*SI)->begin(), E = (*SI)->end(); | 
 |          I != E && I->getOpcode() == X86::PHI; ++I) { | 
 |       if (RegMap->getRegClass(I->getOperand(0).getReg()) == | 
 |           X86::RFPRegisterClass) { | 
 |         ContainsFPCode = true; | 
 |         break; | 
 |       } | 
 |     } | 
 |  | 
 |   // Final check, check LLVM BB's that are successors to the LLVM BB | 
 |   // corresponding to BB for FP PHI nodes. | 
 |   const BasicBlock *LLVMBB = BB->getBasicBlock(); | 
 |   const PHINode *PN; | 
 |   if (!ContainsFPCode) | 
 |     for (succ_const_iterator SI = succ_begin(LLVMBB), E = succ_end(LLVMBB); | 
 |          SI != E && !ContainsFPCode; ++SI) | 
 |       for (BasicBlock::const_iterator II = SI->begin(); | 
 |            (PN = dyn_cast<PHINode>(II)); ++II) | 
 |         if (PN->getType()->isFloatingPoint()) { | 
 |           ContainsFPCode = true; | 
 |           break; | 
 |         } | 
 |  | 
 |  | 
 |   // Insert FP_REG_KILL instructions into basic blocks that need them.  This | 
 |   // only occurs due to the floating point stackifier not being aggressive | 
 |   // enough to handle arbitrary global stackification. | 
 |   // | 
 |   // Currently we insert an FP_REG_KILL instruction into each block that uses or | 
 |   // defines a floating point virtual register. | 
 |   // | 
 |   // When the global register allocators (like linear scan) finally update live | 
 |   // variable analysis, we can keep floating point values in registers across | 
 |   // basic blocks.  This will be a huge win, but we are waiting on the global | 
 |   // allocators before we can do this. | 
 |   // | 
 |   if (ContainsFPCode) { | 
 |     BuildMI(*BB, BB->getFirstTerminator(), X86::FP_REG_KILL, 0); | 
 |     ++NumFPKill; | 
 |   } | 
 |  | 
 |   // Clear state used for selection. | 
 |   ExprMap.clear(); | 
 |   RegPressureMap.clear(); | 
 | } | 
 |  | 
 |  | 
 | // ComputeRegPressure - Compute the RegPressureMap, which is an approximation | 
 | // for the number of registers required to compute each node.  This is basically | 
 | // computing a generalized form of the Sethi-Ullman number for each node. | 
 | unsigned ISel::ComputeRegPressure(SDOperand O) { | 
 |   SDNode *N = O.Val; | 
 |   unsigned &Result = RegPressureMap[N]; | 
 |   if (Result) return Result; | 
 |  | 
 |   // FIXME: Should operations like CALL (which clobber lots o regs) have a | 
 |   // higher fixed cost?? | 
 |  | 
 |   if (N->getNumOperands() == 0) { | 
 |     Result = 1; | 
 |   } else { | 
 |     unsigned MaxRegUse = 0; | 
 |     unsigned NumExtraMaxRegUsers = 0; | 
 |     for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { | 
 |       unsigned Regs; | 
 |       if (N->getOperand(i).getOpcode() == ISD::Constant) | 
 |         Regs = 0; | 
 |       else | 
 |         Regs = ComputeRegPressure(N->getOperand(i)); | 
 |       if (Regs > MaxRegUse) { | 
 |         MaxRegUse = Regs; | 
 |         NumExtraMaxRegUsers = 0; | 
 |       } else if (Regs == MaxRegUse && | 
 |                  N->getOperand(i).getValueType() != MVT::Other) { | 
 |         ++NumExtraMaxRegUsers; | 
 |       } | 
 |     } | 
 |  | 
 |     if (O.getOpcode() != ISD::TokenFactor) | 
 |       Result = MaxRegUse+NumExtraMaxRegUsers; | 
 |     else | 
 |       Result = MaxRegUse == 1 ? 0 : MaxRegUse-1; | 
 |   } | 
 |  | 
 |   //std::cerr << " WEIGHT: " << Result << " ";  N->dump(); std::cerr << "\n"; | 
 |   return Result; | 
 | } | 
 |  | 
 | /// NodeTransitivelyUsesValue - Return true if N or any of its uses uses Op. | 
 | /// The DAG cannot have cycles in it, by definition, so the visited set is not | 
 | /// needed to prevent infinite loops.  The DAG CAN, however, have unbounded | 
 | /// reuse, so it prevents exponential cases. | 
 | /// | 
 | static bool NodeTransitivelyUsesValue(SDOperand N, SDOperand Op, | 
 |                                       std::set<SDNode*> &Visited) { | 
 |   if (N == Op) return true;                        // Found it. | 
 |   SDNode *Node = N.Val; | 
 |   if (Node->getNumOperands() == 0 ||      // Leaf? | 
 |       Node->getNodeDepth() <= Op.getNodeDepth()) return false; // Can't find it? | 
 |   if (!Visited.insert(Node).second) return false;  // Already visited? | 
 |  | 
 |   // Recurse for the first N-1 operands. | 
 |   for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) | 
 |     if (NodeTransitivelyUsesValue(Node->getOperand(i), Op, Visited)) | 
 |       return true; | 
 |  | 
 |   // Tail recurse for the last operand. | 
 |   return NodeTransitivelyUsesValue(Node->getOperand(0), Op, Visited); | 
 | } | 
 |  | 
 | X86AddressMode ISel::SelectAddrExprs(const X86ISelAddressMode &IAM) { | 
 |   X86AddressMode Result; | 
 |  | 
 |   // If we need to emit two register operands, emit the one with the highest | 
 |   // register pressure first. | 
 |   if (IAM.BaseType == X86ISelAddressMode::RegBase && | 
 |       IAM.Base.Reg.Val && IAM.IndexReg.Val) { | 
 |     bool EmitBaseThenIndex; | 
 |     if (getRegPressure(IAM.Base.Reg) > getRegPressure(IAM.IndexReg)) { | 
 |       std::set<SDNode*> Visited; | 
 |       EmitBaseThenIndex = true; | 
 |       // If Base ends up pointing to Index, we must emit index first.  This is | 
 |       // because of the way we fold loads, we may end up doing bad things with | 
 |       // the folded add. | 
 |       if (NodeTransitivelyUsesValue(IAM.Base.Reg, IAM.IndexReg, Visited)) | 
 |         EmitBaseThenIndex = false; | 
 |     } else { | 
 |       std::set<SDNode*> Visited; | 
 |       EmitBaseThenIndex = false; | 
 |       // If Base ends up pointing to Index, we must emit index first.  This is | 
 |       // because of the way we fold loads, we may end up doing bad things with | 
 |       // the folded add. | 
 |       if (NodeTransitivelyUsesValue(IAM.IndexReg, IAM.Base.Reg, Visited)) | 
 |         EmitBaseThenIndex = true; | 
 |     } | 
 |  | 
 |     if (EmitBaseThenIndex) { | 
 |       Result.Base.Reg = SelectExpr(IAM.Base.Reg); | 
 |       Result.IndexReg = SelectExpr(IAM.IndexReg); | 
 |     } else { | 
 |       Result.IndexReg = SelectExpr(IAM.IndexReg); | 
 |       Result.Base.Reg = SelectExpr(IAM.Base.Reg); | 
 |     } | 
 |  | 
 |   } else if (IAM.BaseType == X86ISelAddressMode::RegBase && IAM.Base.Reg.Val) { | 
 |     Result.Base.Reg = SelectExpr(IAM.Base.Reg); | 
 |   } else if (IAM.IndexReg.Val) { | 
 |     Result.IndexReg = SelectExpr(IAM.IndexReg); | 
 |   } | 
 |  | 
 |   switch (IAM.BaseType) { | 
 |   case X86ISelAddressMode::RegBase: | 
 |     Result.BaseType = X86AddressMode::RegBase; | 
 |     break; | 
 |   case X86ISelAddressMode::FrameIndexBase: | 
 |     Result.BaseType = X86AddressMode::FrameIndexBase; | 
 |     Result.Base.FrameIndex = IAM.Base.FrameIndex; | 
 |     break; | 
 |   default: | 
 |     assert(0 && "Unknown base type!"); | 
 |     break; | 
 |   } | 
 |   Result.Scale = IAM.Scale; | 
 |   Result.Disp = IAM.Disp; | 
 |   Result.GV = IAM.GV; | 
 |   return Result; | 
 | } | 
 |  | 
 | /// SelectAddress - Pattern match the maximal addressing mode for this node and | 
 | /// emit all of the leaf registers. | 
 | void ISel::SelectAddress(SDOperand N, X86AddressMode &AM) { | 
 |   X86ISelAddressMode IAM; | 
 |   MatchAddress(N, IAM); | 
 |   AM = SelectAddrExprs(IAM); | 
 | } | 
 |  | 
 | /// MatchAddress - Add the specified node to the specified addressing mode, | 
 | /// returning true if it cannot be done.  This just pattern matches for the | 
 | /// addressing mode, it does not cause any code to be emitted.  For that, use | 
 | /// SelectAddress. | 
 | bool ISel::MatchAddress(SDOperand N, X86ISelAddressMode &AM) { | 
 |   switch (N.getOpcode()) { | 
 |   default: break; | 
 |   case ISD::FrameIndex: | 
 |     if (AM.BaseType == X86ISelAddressMode::RegBase && AM.Base.Reg.Val == 0) { | 
 |       AM.BaseType = X86ISelAddressMode::FrameIndexBase; | 
 |       AM.Base.FrameIndex = cast<FrameIndexSDNode>(N)->getIndex(); | 
 |       return false; | 
 |     } | 
 |     break; | 
 |   case ISD::GlobalAddress: | 
 |     if (AM.GV == 0) { | 
 |       AM.GV = cast<GlobalAddressSDNode>(N)->getGlobal(); | 
 |       return false; | 
 |     } | 
 |     break; | 
 |   case ISD::Constant: | 
 |     AM.Disp += cast<ConstantSDNode>(N)->getValue(); | 
 |     return false; | 
 |   case ISD::SHL: | 
 |     // We might have folded the load into this shift, so don't regen the value | 
 |     // if so. | 
 |     if (ExprMap.count(N)) break; | 
 |  | 
 |     if (AM.IndexReg.Val == 0 && AM.Scale == 1) | 
 |       if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1))) { | 
 |         unsigned Val = CN->getValue(); | 
 |         if (Val == 1 || Val == 2 || Val == 3) { | 
 |           AM.Scale = 1 << Val; | 
 |           SDOperand ShVal = N.Val->getOperand(0); | 
 |  | 
 |           // Okay, we know that we have a scale by now.  However, if the scaled | 
 |           // value is an add of something and a constant, we can fold the | 
 |           // constant into the disp field here. | 
 |           if (ShVal.Val->getOpcode() == ISD::ADD && ShVal.hasOneUse() && | 
 |               isa<ConstantSDNode>(ShVal.Val->getOperand(1))) { | 
 |             AM.IndexReg = ShVal.Val->getOperand(0); | 
 |             ConstantSDNode *AddVal = | 
 |               cast<ConstantSDNode>(ShVal.Val->getOperand(1)); | 
 |             AM.Disp += AddVal->getValue() << Val; | 
 |           } else { | 
 |             AM.IndexReg = ShVal; | 
 |           } | 
 |           return false; | 
 |         } | 
 |       } | 
 |     break; | 
 |   case ISD::MUL: | 
 |     // We might have folded the load into this mul, so don't regen the value if | 
 |     // so. | 
 |     if (ExprMap.count(N)) break; | 
 |  | 
 |     // X*[3,5,9] -> X+X*[2,4,8] | 
 |     if (AM.IndexReg.Val == 0 && AM.BaseType == X86ISelAddressMode::RegBase && | 
 |         AM.Base.Reg.Val == 0) | 
 |       if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1))) | 
 |         if (CN->getValue() == 3 || CN->getValue() == 5 || CN->getValue() == 9) { | 
 |           AM.Scale = unsigned(CN->getValue())-1; | 
 |  | 
 |           SDOperand MulVal = N.Val->getOperand(0); | 
 |           SDOperand Reg; | 
 |  | 
 |           // Okay, we know that we have a scale by now.  However, if the scaled | 
 |           // value is an add of something and a constant, we can fold the | 
 |           // constant into the disp field here. | 
 |           if (MulVal.Val->getOpcode() == ISD::ADD && MulVal.hasOneUse() && | 
 |               isa<ConstantSDNode>(MulVal.Val->getOperand(1))) { | 
 |             Reg = MulVal.Val->getOperand(0); | 
 |             ConstantSDNode *AddVal = | 
 |               cast<ConstantSDNode>(MulVal.Val->getOperand(1)); | 
 |             AM.Disp += AddVal->getValue() * CN->getValue(); | 
 |           } else { | 
 |             Reg = N.Val->getOperand(0); | 
 |           } | 
 |  | 
 |           AM.IndexReg = AM.Base.Reg = Reg; | 
 |           return false; | 
 |         } | 
 |     break; | 
 |  | 
 |   case ISD::ADD: { | 
 |     // We might have folded the load into this mul, so don't regen the value if | 
 |     // so. | 
 |     if (ExprMap.count(N)) break; | 
 |  | 
 |     X86ISelAddressMode Backup = AM; | 
 |     if (!MatchAddress(N.Val->getOperand(0), AM) && | 
 |         !MatchAddress(N.Val->getOperand(1), AM)) | 
 |       return false; | 
 |     AM = Backup; | 
 |     if (!MatchAddress(N.Val->getOperand(1), AM) && | 
 |         !MatchAddress(N.Val->getOperand(0), AM)) | 
 |       return false; | 
 |     AM = Backup; | 
 |     break; | 
 |   } | 
 |   } | 
 |  | 
 |   // Is the base register already occupied? | 
 |   if (AM.BaseType != X86ISelAddressMode::RegBase || AM.Base.Reg.Val) { | 
 |     // If so, check to see if the scale index register is set. | 
 |     if (AM.IndexReg.Val == 0) { | 
 |       AM.IndexReg = N; | 
 |       AM.Scale = 1; | 
 |       return false; | 
 |     } | 
 |  | 
 |     // Otherwise, we cannot select it. | 
 |     return true; | 
 |   } | 
 |  | 
 |   // Default, generate it as a register. | 
 |   AM.BaseType = X86ISelAddressMode::RegBase; | 
 |   AM.Base.Reg = N; | 
 |   return false; | 
 | } | 
 |  | 
 | /// Emit2SetCCsAndLogical - Emit the following sequence of instructions, | 
 | /// assuming that the temporary registers are in the 8-bit register class. | 
 | /// | 
 | ///  Tmp1 = setcc1 | 
 | ///  Tmp2 = setcc2 | 
 | ///  DestReg = logicalop Tmp1, Tmp2 | 
 | /// | 
 | static void Emit2SetCCsAndLogical(MachineBasicBlock *BB, unsigned SetCC1, | 
 |                                   unsigned SetCC2, unsigned LogicalOp, | 
 |                                   unsigned DestReg) { | 
 |   SSARegMap *RegMap = BB->getParent()->getSSARegMap(); | 
 |   unsigned Tmp1 = RegMap->createVirtualRegister(X86::R8RegisterClass); | 
 |   unsigned Tmp2 = RegMap->createVirtualRegister(X86::R8RegisterClass); | 
 |   BuildMI(BB, SetCC1, 0, Tmp1); | 
 |   BuildMI(BB, SetCC2, 0, Tmp2); | 
 |   BuildMI(BB, LogicalOp, 2, DestReg).addReg(Tmp1).addReg(Tmp2); | 
 | } | 
 |  | 
 | /// EmitSetCC - Emit the code to set the specified 8-bit register to 1 if the | 
 | /// condition codes match the specified SetCCOpcode.  Note that some conditions | 
 | /// require multiple instructions to generate the correct value. | 
 | static void EmitSetCC(MachineBasicBlock *BB, unsigned DestReg, | 
 |                       ISD::CondCode SetCCOpcode, bool isFP) { | 
 |   unsigned Opc; | 
 |   if (!isFP) { | 
 |     switch (SetCCOpcode) { | 
 |     default: assert(0 && "Illegal integer SetCC!"); | 
 |     case ISD::SETEQ: Opc = X86::SETEr; break; | 
 |     case ISD::SETGT: Opc = X86::SETGr; break; | 
 |     case ISD::SETGE: Opc = X86::SETGEr; break; | 
 |     case ISD::SETLT: Opc = X86::SETLr; break; | 
 |     case ISD::SETLE: Opc = X86::SETLEr; break; | 
 |     case ISD::SETNE: Opc = X86::SETNEr; break; | 
 |     case ISD::SETULT: Opc = X86::SETBr; break; | 
 |     case ISD::SETUGT: Opc = X86::SETAr; break; | 
 |     case ISD::SETULE: Opc = X86::SETBEr; break; | 
 |     case ISD::SETUGE: Opc = X86::SETAEr; break; | 
 |     } | 
 |   } else { | 
 |     // On a floating point condition, the flags are set as follows: | 
 |     // ZF  PF  CF   op | 
 |     //  0 | 0 | 0 | X > Y | 
 |     //  0 | 0 | 1 | X < Y | 
 |     //  1 | 0 | 0 | X == Y | 
 |     //  1 | 1 | 1 | unordered | 
 |     // | 
 |     switch (SetCCOpcode) { | 
 |     default: assert(0 && "Invalid FP setcc!"); | 
 |     case ISD::SETUEQ: | 
 |     case ISD::SETEQ: | 
 |       Opc = X86::SETEr;    // True if ZF = 1 | 
 |       break; | 
 |     case ISD::SETOGT: | 
 |     case ISD::SETGT: | 
 |       Opc = X86::SETAr;    // True if CF = 0 and ZF = 0 | 
 |       break; | 
 |     case ISD::SETOGE: | 
 |     case ISD::SETGE: | 
 |       Opc = X86::SETAEr;   // True if CF = 0 | 
 |       break; | 
 |     case ISD::SETULT: | 
 |     case ISD::SETLT: | 
 |       Opc = X86::SETBr;    // True if CF = 1 | 
 |       break; | 
 |     case ISD::SETULE: | 
 |     case ISD::SETLE: | 
 |       Opc = X86::SETBEr;   // True if CF = 1 or ZF = 1 | 
 |       break; | 
 |     case ISD::SETONE: | 
 |     case ISD::SETNE: | 
 |       Opc = X86::SETNEr;   // True if ZF = 0 | 
 |       break; | 
 |     case ISD::SETUO: | 
 |       Opc = X86::SETPr;    // True if PF = 1 | 
 |       break; | 
 |     case ISD::SETO: | 
 |       Opc = X86::SETNPr;   // True if PF = 0 | 
 |       break; | 
 |     case ISD::SETOEQ:      // !PF & ZF | 
 |       Emit2SetCCsAndLogical(BB, X86::SETNPr, X86::SETEr, X86::AND8rr, DestReg); | 
 |       return; | 
 |     case ISD::SETOLT:      // !PF & CF | 
 |       Emit2SetCCsAndLogical(BB, X86::SETNPr, X86::SETBr, X86::AND8rr, DestReg); | 
 |       return; | 
 |     case ISD::SETOLE:      // !PF & (CF || ZF) | 
 |       Emit2SetCCsAndLogical(BB, X86::SETNPr, X86::SETBEr, X86::AND8rr, DestReg); | 
 |       return; | 
 |     case ISD::SETUGT:      // PF | (!ZF & !CF) | 
 |       Emit2SetCCsAndLogical(BB, X86::SETPr, X86::SETAr, X86::OR8rr, DestReg); | 
 |       return; | 
 |     case ISD::SETUGE:      // PF | !CF | 
 |       Emit2SetCCsAndLogical(BB, X86::SETPr, X86::SETAEr, X86::OR8rr, DestReg); | 
 |       return; | 
 |     case ISD::SETUNE:      // PF | !ZF | 
 |       Emit2SetCCsAndLogical(BB, X86::SETPr, X86::SETNEr, X86::OR8rr, DestReg); | 
 |       return; | 
 |     } | 
 |   } | 
 |   BuildMI(BB, Opc, 0, DestReg); | 
 | } | 
 |  | 
 |  | 
 | /// EmitBranchCC - Emit code into BB that arranges for control to transfer to | 
 | /// the Dest block if the Cond condition is true.  If we cannot fold this | 
 | /// condition into the branch, return true. | 
 | /// | 
 | bool ISel::EmitBranchCC(MachineBasicBlock *Dest, SDOperand Chain, | 
 |                         SDOperand Cond) { | 
 |   // FIXME: Evaluate whether it would be good to emit code like (X < Y) | (A > | 
 |   // B) using two conditional branches instead of one condbr, two setcc's, and | 
 |   // an or. | 
 |   if ((Cond.getOpcode() == ISD::OR || | 
 |        Cond.getOpcode() == ISD::AND) && Cond.Val->hasOneUse()) { | 
 |     // And and or set the flags for us, so there is no need to emit a TST of the | 
 |     // result.  It is only safe to do this if there is only a single use of the | 
 |     // AND/OR though, otherwise we don't know it will be emitted here. | 
 |     Select(Chain); | 
 |     SelectExpr(Cond); | 
 |     BuildMI(BB, X86::JNE, 1).addMBB(Dest); | 
 |     return false; | 
 |   } | 
 |  | 
 |   // Codegen br not C -> JE. | 
 |   if (Cond.getOpcode() == ISD::XOR) | 
 |     if (ConstantSDNode *NC = dyn_cast<ConstantSDNode>(Cond.Val->getOperand(1))) | 
 |       if (NC->isAllOnesValue()) { | 
 |         unsigned CondR; | 
 |         if (getRegPressure(Chain) > getRegPressure(Cond)) { | 
 |           Select(Chain); | 
 |           CondR = SelectExpr(Cond.Val->getOperand(0)); | 
 |         } else { | 
 |           CondR = SelectExpr(Cond.Val->getOperand(0)); | 
 |           Select(Chain); | 
 |         } | 
 |         BuildMI(BB, X86::TEST8rr, 2).addReg(CondR).addReg(CondR); | 
 |         BuildMI(BB, X86::JE, 1).addMBB(Dest); | 
 |         return false; | 
 |       } | 
 |  | 
 |   SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(Cond); | 
 |   if (SetCC == 0) | 
 |     return true;                       // Can only handle simple setcc's so far. | 
 |  | 
 |   unsigned Opc; | 
 |  | 
 |   // Handle integer conditions first. | 
 |   if (MVT::isInteger(SetCC->getOperand(0).getValueType())) { | 
 |     switch (SetCC->getCondition()) { | 
 |     default: assert(0 && "Illegal integer SetCC!"); | 
 |     case ISD::SETEQ: Opc = X86::JE; break; | 
 |     case ISD::SETGT: Opc = X86::JG; break; | 
 |     case ISD::SETGE: Opc = X86::JGE; break; | 
 |     case ISD::SETLT: Opc = X86::JL; break; | 
 |     case ISD::SETLE: Opc = X86::JLE; break; | 
 |     case ISD::SETNE: Opc = X86::JNE; break; | 
 |     case ISD::SETULT: Opc = X86::JB; break; | 
 |     case ISD::SETUGT: Opc = X86::JA; break; | 
 |     case ISD::SETULE: Opc = X86::JBE; break; | 
 |     case ISD::SETUGE: Opc = X86::JAE; break; | 
 |     } | 
 |     Select(Chain); | 
 |     EmitCMP(SetCC->getOperand(0), SetCC->getOperand(1), SetCC->hasOneUse()); | 
 |     BuildMI(BB, Opc, 1).addMBB(Dest); | 
 |     return false; | 
 |   } | 
 |  | 
 |   unsigned Opc2 = 0;  // Second branch if needed. | 
 |  | 
 |   // On a floating point condition, the flags are set as follows: | 
 |   // ZF  PF  CF   op | 
 |   //  0 | 0 | 0 | X > Y | 
 |   //  0 | 0 | 1 | X < Y | 
 |   //  1 | 0 | 0 | X == Y | 
 |   //  1 | 1 | 1 | unordered | 
 |   // | 
 |   switch (SetCC->getCondition()) { | 
 |   default: assert(0 && "Invalid FP setcc!"); | 
 |   case ISD::SETUEQ: | 
 |   case ISD::SETEQ:   Opc = X86::JE;  break;     // True if ZF = 1 | 
 |   case ISD::SETOGT: | 
 |   case ISD::SETGT:   Opc = X86::JA;  break;     // True if CF = 0 and ZF = 0 | 
 |   case ISD::SETOGE: | 
 |   case ISD::SETGE:   Opc = X86::JAE; break;     // True if CF = 0 | 
 |   case ISD::SETULT: | 
 |   case ISD::SETLT:   Opc = X86::JB;  break;     // True if CF = 1 | 
 |   case ISD::SETULE: | 
 |   case ISD::SETLE:   Opc = X86::JBE; break;     // True if CF = 1 or ZF = 1 | 
 |   case ISD::SETONE: | 
 |   case ISD::SETNE:   Opc = X86::JNE; break;     // True if ZF = 0 | 
 |   case ISD::SETUO:   Opc = X86::JP;  break;     // True if PF = 1 | 
 |   case ISD::SETO:    Opc = X86::JNP; break;     // True if PF = 0 | 
 |   case ISD::SETUGT:      // PF = 1 | (ZF = 0 & CF = 0) | 
 |     Opc = X86::JA;       // ZF = 0 & CF = 0 | 
 |     Opc2 = X86::JP;      // PF = 1 | 
 |     break; | 
 |   case ISD::SETUGE:      // PF = 1 | CF = 0 | 
 |     Opc = X86::JAE;      // CF = 0 | 
 |     Opc2 = X86::JP;      // PF = 1 | 
 |     break; | 
 |   case ISD::SETUNE:      // PF = 1 | ZF = 0 | 
 |     Opc = X86::JNE;      // ZF = 0 | 
 |     Opc2 = X86::JP;      // PF = 1 | 
 |     break; | 
 |   case ISD::SETOEQ:      // PF = 0 & ZF = 1 | 
 |     //X86::JNP, X86::JE | 
 |     //X86::AND8rr | 
 |     return true;    // FIXME: Emit more efficient code for this branch. | 
 |   case ISD::SETOLT:      // PF = 0 & CF = 1 | 
 |     //X86::JNP, X86::JB | 
 |     //X86::AND8rr | 
 |     return true;    // FIXME: Emit more efficient code for this branch. | 
 |   case ISD::SETOLE:      // PF = 0 & (CF = 1 || ZF = 1) | 
 |     //X86::JNP, X86::JBE | 
 |     //X86::AND8rr | 
 |     return true;    // FIXME: Emit more efficient code for this branch. | 
 |   } | 
 |  | 
 |   Select(Chain); | 
 |   EmitCMP(SetCC->getOperand(0), SetCC->getOperand(1), SetCC->hasOneUse()); | 
 |   BuildMI(BB, Opc, 1).addMBB(Dest); | 
 |   if (Opc2) | 
 |     BuildMI(BB, Opc2, 1).addMBB(Dest); | 
 |   return false; | 
 | } | 
 |  | 
 | /// EmitSelectCC - Emit code into BB that performs a select operation between | 
 | /// the two registers RTrue and RFalse, generating a result into RDest.  Return | 
 | /// true if the fold cannot be performed. | 
 | /// | 
 | void ISel::EmitSelectCC(SDOperand Cond, MVT::ValueType SVT, | 
 |                         unsigned RTrue, unsigned RFalse, unsigned RDest) { | 
 |   enum Condition { | 
 |     EQ, NE, LT, LE, GT, GE, B, BE, A, AE, P, NP, | 
 |     NOT_SET | 
 |   } CondCode = NOT_SET; | 
 |  | 
 |   static const unsigned CMOVTAB16[] = { | 
 |     X86::CMOVE16rr,  X86::CMOVNE16rr, X86::CMOVL16rr,  X86::CMOVLE16rr, | 
 |     X86::CMOVG16rr,  X86::CMOVGE16rr, X86::CMOVB16rr,  X86::CMOVBE16rr, | 
 |     X86::CMOVA16rr,  X86::CMOVAE16rr, X86::CMOVP16rr,  X86::CMOVNP16rr, | 
 |   }; | 
 |   static const unsigned CMOVTAB32[] = { | 
 |     X86::CMOVE32rr,  X86::CMOVNE32rr, X86::CMOVL32rr,  X86::CMOVLE32rr, | 
 |     X86::CMOVG32rr,  X86::CMOVGE32rr, X86::CMOVB32rr,  X86::CMOVBE32rr, | 
 |     X86::CMOVA32rr,  X86::CMOVAE32rr, X86::CMOVP32rr,  X86::CMOVNP32rr, | 
 |   }; | 
 |   static const unsigned CMOVTABFP[] = { | 
 |     X86::FCMOVE ,  X86::FCMOVNE, /*missing*/0, /*missing*/0, | 
 |     /*missing*/0,  /*missing*/0, X86::FCMOVB , X86::FCMOVBE, | 
 |     X86::FCMOVA ,  X86::FCMOVAE, X86::FCMOVP , X86::FCMOVNP | 
 |   }; | 
 |  | 
 |   if (SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(Cond)) { | 
 |     if (MVT::isInteger(SetCC->getOperand(0).getValueType())) { | 
 |       switch (SetCC->getCondition()) { | 
 |       default: assert(0 && "Unknown integer comparison!"); | 
 |       case ISD::SETEQ:  CondCode = EQ; break; | 
 |       case ISD::SETGT:  CondCode = GT; break; | 
 |       case ISD::SETGE:  CondCode = GE; break; | 
 |       case ISD::SETLT:  CondCode = LT; break; | 
 |       case ISD::SETLE:  CondCode = LE; break; | 
 |       case ISD::SETNE:  CondCode = NE; break; | 
 |       case ISD::SETULT: CondCode = B; break; | 
 |       case ISD::SETUGT: CondCode = A; break; | 
 |       case ISD::SETULE: CondCode = BE; break; | 
 |       case ISD::SETUGE: CondCode = AE; break; | 
 |       } | 
 |     } else { | 
 |       // On a floating point condition, the flags are set as follows: | 
 |       // ZF  PF  CF   op | 
 |       //  0 | 0 | 0 | X > Y | 
 |       //  0 | 0 | 1 | X < Y | 
 |       //  1 | 0 | 0 | X == Y | 
 |       //  1 | 1 | 1 | unordered | 
 |       // | 
 |       switch (SetCC->getCondition()) { | 
 |       default: assert(0 && "Unknown FP comparison!"); | 
 |       case ISD::SETUEQ: | 
 |       case ISD::SETEQ:  CondCode = EQ; break;     // True if ZF = 1 | 
 |       case ISD::SETOGT: | 
 |       case ISD::SETGT:  CondCode = A;  break;     // True if CF = 0 and ZF = 0 | 
 |       case ISD::SETOGE: | 
 |       case ISD::SETGE:  CondCode = AE; break;     // True if CF = 0 | 
 |       case ISD::SETULT: | 
 |       case ISD::SETLT:  CondCode = B;  break;     // True if CF = 1 | 
 |       case ISD::SETULE: | 
 |       case ISD::SETLE:  CondCode = BE; break;     // True if CF = 1 or ZF = 1 | 
 |       case ISD::SETONE: | 
 |       case ISD::SETNE:  CondCode = NE; break;     // True if ZF = 0 | 
 |       case ISD::SETUO:  CondCode = P;  break;     // True if PF = 1 | 
 |       case ISD::SETO:   CondCode = NP; break;     // True if PF = 0 | 
 |       case ISD::SETUGT:      // PF = 1 | (ZF = 0 & CF = 0) | 
 |       case ISD::SETUGE:      // PF = 1 | CF = 0 | 
 |       case ISD::SETUNE:      // PF = 1 | ZF = 0 | 
 |       case ISD::SETOEQ:      // PF = 0 & ZF = 1 | 
 |       case ISD::SETOLT:      // PF = 0 & CF = 1 | 
 |       case ISD::SETOLE:      // PF = 0 & (CF = 1 || ZF = 1) | 
 |         // We cannot emit this comparison as a single cmov. | 
 |         break; | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   unsigned Opc = 0; | 
 |   if (CondCode != NOT_SET) { | 
 |     switch (SVT) { | 
 |     default: assert(0 && "Cannot select this type!"); | 
 |     case MVT::i16: Opc = CMOVTAB16[CondCode]; break; | 
 |     case MVT::i32: Opc = CMOVTAB32[CondCode]; break; | 
 |     case MVT::f64: Opc = CMOVTABFP[CondCode]; break; | 
 |     } | 
 |   } | 
 |  | 
 |   // Finally, if we weren't able to fold this, just emit the condition and test | 
 |   // it. | 
 |   if (CondCode == NOT_SET || Opc == 0) { | 
 |     // Get the condition into the zero flag. | 
 |     unsigned CondReg = SelectExpr(Cond); | 
 |     BuildMI(BB, X86::TEST8rr, 2).addReg(CondReg).addReg(CondReg); | 
 |  | 
 |     switch (SVT) { | 
 |     default: assert(0 && "Cannot select this type!"); | 
 |     case MVT::i16: Opc = X86::CMOVE16rr; break; | 
 |     case MVT::i32: Opc = X86::CMOVE32rr; break; | 
 |     case MVT::f64: Opc = X86::FCMOVE; break; | 
 |     } | 
 |   } else { | 
 |     // FIXME: CMP R, 0 -> TEST R, R | 
 |     EmitCMP(Cond.getOperand(0), Cond.getOperand(1), Cond.Val->hasOneUse()); | 
 |     std::swap(RTrue, RFalse); | 
 |   } | 
 |   BuildMI(BB, Opc, 2, RDest).addReg(RTrue).addReg(RFalse); | 
 | } | 
 |  | 
 | void ISel::EmitCMP(SDOperand LHS, SDOperand RHS, bool HasOneUse) { | 
 |   unsigned Opc; | 
 |   if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(RHS)) { | 
 |     Opc = 0; | 
 |     if (HasOneUse && isFoldableLoad(LHS, RHS)) { | 
 |       switch (RHS.getValueType()) { | 
 |       default: break; | 
 |       case MVT::i1: | 
 |       case MVT::i8:  Opc = X86::CMP8mi;  break; | 
 |       case MVT::i16: Opc = X86::CMP16mi; break; | 
 |       case MVT::i32: Opc = X86::CMP32mi; break; | 
 |       } | 
 |       if (Opc) { | 
 |         X86AddressMode AM; | 
 |         EmitFoldedLoad(LHS, AM); | 
 |         addFullAddress(BuildMI(BB, Opc, 5), AM).addImm(CN->getValue()); | 
 |         return; | 
 |       } | 
 |     } | 
 |  | 
 |     switch (RHS.getValueType()) { | 
 |     default: break; | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Opc = X86::CMP8ri;  break; | 
 |     case MVT::i16: Opc = X86::CMP16ri; break; | 
 |     case MVT::i32: Opc = X86::CMP32ri; break; | 
 |     } | 
 |     if (Opc) { | 
 |       unsigned Tmp1 = SelectExpr(LHS); | 
 |       BuildMI(BB, Opc, 2).addReg(Tmp1).addImm(CN->getValue()); | 
 |       return; | 
 |     } | 
 |   } else if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(RHS)) { | 
 |     if (CN->isExactlyValue(+0.0) || | 
 |         CN->isExactlyValue(-0.0)) { | 
 |       unsigned Reg = SelectExpr(LHS); | 
 |       BuildMI(BB, X86::FTST, 1).addReg(Reg); | 
 |       BuildMI(BB, X86::FNSTSW8r, 0); | 
 |       BuildMI(BB, X86::SAHF, 1); | 
 |       return; | 
 |     } | 
 |   } | 
 |  | 
 |   Opc = 0; | 
 |   if (HasOneUse && isFoldableLoad(LHS, RHS)) { | 
 |     switch (RHS.getValueType()) { | 
 |     default: break; | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Opc = X86::CMP8mr;  break; | 
 |     case MVT::i16: Opc = X86::CMP16mr; break; | 
 |     case MVT::i32: Opc = X86::CMP32mr; break; | 
 |     } | 
 |     if (Opc) { | 
 |       X86AddressMode AM; | 
 |       EmitFoldedLoad(LHS, AM); | 
 |       unsigned Reg = SelectExpr(RHS); | 
 |       addFullAddress(BuildMI(BB, Opc, 5), AM).addReg(Reg); | 
 |       return; | 
 |     } | 
 |   } | 
 |  | 
 |   switch (LHS.getValueType()) { | 
 |   default: assert(0 && "Cannot compare this value!"); | 
 |   case MVT::i1: | 
 |   case MVT::i8:  Opc = X86::CMP8rr;  break; | 
 |   case MVT::i16: Opc = X86::CMP16rr; break; | 
 |   case MVT::i32: Opc = X86::CMP32rr; break; | 
 |   case MVT::f64: Opc = X86::FUCOMIr; break; | 
 |   } | 
 |   unsigned Tmp1, Tmp2; | 
 |   if (getRegPressure(LHS) > getRegPressure(RHS)) { | 
 |     Tmp1 = SelectExpr(LHS); | 
 |     Tmp2 = SelectExpr(RHS); | 
 |   } else { | 
 |     Tmp2 = SelectExpr(RHS); | 
 |     Tmp1 = SelectExpr(LHS); | 
 |   } | 
 |   BuildMI(BB, Opc, 2).addReg(Tmp1).addReg(Tmp2); | 
 | } | 
 |  | 
 | /// isFoldableLoad - Return true if this is a load instruction that can safely | 
 | /// be folded into an operation that uses it. | 
 | bool ISel::isFoldableLoad(SDOperand Op, SDOperand OtherOp, bool FloatPromoteOk){ | 
 |   if (Op.getOpcode() == ISD::LOAD) { | 
 |     // FIXME: currently can't fold constant pool indexes. | 
 |     if (isa<ConstantPoolSDNode>(Op.getOperand(1))) | 
 |       return false; | 
 |   } else if (FloatPromoteOk && Op.getOpcode() == ISD::EXTLOAD && | 
 |              cast<MVTSDNode>(Op)->getExtraValueType() == MVT::f32) { | 
 |     // FIXME: currently can't fold constant pool indexes. | 
 |     if (isa<ConstantPoolSDNode>(Op.getOperand(1))) | 
 |       return false; | 
 |   } else { | 
 |     return false; | 
 |   } | 
 |  | 
 |   // If this load has already been emitted, we clearly can't fold it. | 
 |   assert(Op.ResNo == 0 && "Not a use of the value of the load?"); | 
 |   if (ExprMap.count(Op.getValue(1))) return false; | 
 |   assert(!ExprMap.count(Op.getValue(0)) && "Value in map but not token chain?"); | 
 |   assert(!ExprMap.count(Op.getValue(1))&&"Token lowered but value not in map?"); | 
 |  | 
 |   // If there is not just one use of its value, we cannot fold. | 
 |   if (!Op.Val->hasNUsesOfValue(1, 0)) return false; | 
 |  | 
 |   // Finally, we cannot fold the load into the operation if this would induce a | 
 |   // cycle into the resultant dag.  To check for this, see if OtherOp (the other | 
 |   // operand of the operation we are folding the load into) can possible use the | 
 |   // chain node defined by the load. | 
 |   if (OtherOp.Val && !Op.Val->hasNUsesOfValue(0, 1)) { // Has uses of chain? | 
 |     std::set<SDNode*> Visited; | 
 |     if (NodeTransitivelyUsesValue(OtherOp, Op.getValue(1), Visited)) | 
 |       return false; | 
 |   } | 
 |   return true; | 
 | } | 
 |  | 
 |  | 
 | /// EmitFoldedLoad - Ensure that the arguments of the load are code generated, | 
 | /// and compute the address being loaded into AM. | 
 | void ISel::EmitFoldedLoad(SDOperand Op, X86AddressMode &AM) { | 
 |   SDOperand Chain   = Op.getOperand(0); | 
 |   SDOperand Address = Op.getOperand(1); | 
 |  | 
 |   if (getRegPressure(Chain) > getRegPressure(Address)) { | 
 |     Select(Chain); | 
 |     SelectAddress(Address, AM); | 
 |   } else { | 
 |     SelectAddress(Address, AM); | 
 |     Select(Chain); | 
 |   } | 
 |  | 
 |   // The chain for this load is now lowered. | 
 |   assert(ExprMap.count(SDOperand(Op.Val, 1)) == 0 && | 
 |          "Load emitted more than once?"); | 
 |   if (!ExprMap.insert(std::make_pair(Op.getValue(1), 1)).second) | 
 |     assert(0 && "Load emitted more than once!"); | 
 | } | 
 |  | 
 | // EmitOrOpOp - Pattern match the expression (Op1|Op2), where we know that op1 | 
 | // and op2 are i8/i16/i32 values with one use each (the or).  If we can form a | 
 | // SHLD or SHRD, emit the instruction (generating the value into DestReg) and | 
 | // return true. | 
 | bool ISel::EmitOrOpOp(SDOperand Op1, SDOperand Op2, unsigned DestReg) { | 
 |   if (Op1.getOpcode() == ISD::SHL && Op2.getOpcode() == ISD::SRL) { | 
 |     // good! | 
 |   } else if (Op2.getOpcode() == ISD::SHL && Op1.getOpcode() == ISD::SRL) { | 
 |     std::swap(Op1, Op2);  // Op1 is the SHL now. | 
 |   } else { | 
 |     return false;  // No match | 
 |   } | 
 |  | 
 |   SDOperand ShlVal = Op1.getOperand(0); | 
 |   SDOperand ShlAmt = Op1.getOperand(1); | 
 |   SDOperand ShrVal = Op2.getOperand(0); | 
 |   SDOperand ShrAmt = Op2.getOperand(1); | 
 |  | 
 |   unsigned RegSize = MVT::getSizeInBits(Op1.getValueType()); | 
 |  | 
 |   // Find out if ShrAmt = 32-ShlAmt  or  ShlAmt = 32-ShrAmt. | 
 |   if (ShlAmt.getOpcode() == ISD::SUB && ShlAmt.getOperand(1) == ShrAmt) | 
 |     if (ConstantSDNode *SubCST = dyn_cast<ConstantSDNode>(ShlAmt.getOperand(0))) | 
 |       if (SubCST->getValue() == RegSize) { | 
 |         // (A >> ShrAmt) | (A << (32-ShrAmt)) ==> ROR A, ShrAmt | 
 |         // (A >> ShrAmt) | (B << (32-ShrAmt)) ==> SHRD A, B, ShrAmt | 
 |         if (ShrVal == ShlVal) { | 
 |           unsigned Reg, ShAmt; | 
 |           if (getRegPressure(ShrVal) > getRegPressure(ShrAmt)) { | 
 |             Reg = SelectExpr(ShrVal); | 
 |             ShAmt = SelectExpr(ShrAmt); | 
 |           } else { | 
 |             ShAmt = SelectExpr(ShrAmt); | 
 |             Reg = SelectExpr(ShrVal); | 
 |           } | 
 |           BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt); | 
 |           unsigned Opc = RegSize == 8 ? X86::ROR8rCL : | 
 |                         (RegSize == 16 ? X86::ROR16rCL : X86::ROR32rCL); | 
 |           BuildMI(BB, Opc, 1, DestReg).addReg(Reg); | 
 |           return true; | 
 |         } else if (RegSize != 8) { | 
 |           unsigned AReg, BReg; | 
 |           if (getRegPressure(ShlVal) > getRegPressure(ShrVal)) { | 
 |             BReg = SelectExpr(ShlVal); | 
 |             AReg = SelectExpr(ShrVal); | 
 |           } else { | 
 |             AReg = SelectExpr(ShrVal); | 
 |             BReg = SelectExpr(ShlVal); | 
 |           } | 
 |           unsigned ShAmt = SelectExpr(ShrAmt); | 
 |           BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt); | 
 |           unsigned Opc = RegSize == 16 ? X86::SHRD16rrCL : X86::SHRD32rrCL; | 
 |           BuildMI(BB, Opc, 2, DestReg).addReg(AReg).addReg(BReg); | 
 |           return true; | 
 |         } | 
 |       } | 
 |  | 
 |   if (ShrAmt.getOpcode() == ISD::SUB && ShrAmt.getOperand(1) == ShlAmt) | 
 |     if (ConstantSDNode *SubCST = dyn_cast<ConstantSDNode>(ShrAmt.getOperand(0))) | 
 |       if (SubCST->getValue() == RegSize) { | 
 |         // (A << ShlAmt) | (A >> (32-ShlAmt)) ==> ROL A, ShrAmt | 
 |         // (A << ShlAmt) | (B >> (32-ShlAmt)) ==> SHLD A, B, ShrAmt | 
 |         if (ShrVal == ShlVal) { | 
 |           unsigned Reg, ShAmt; | 
 |           if (getRegPressure(ShrVal) > getRegPressure(ShlAmt)) { | 
 |             Reg = SelectExpr(ShrVal); | 
 |             ShAmt = SelectExpr(ShlAmt); | 
 |           } else { | 
 |             ShAmt = SelectExpr(ShlAmt); | 
 |             Reg = SelectExpr(ShrVal); | 
 |           } | 
 |           BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt); | 
 |           unsigned Opc = RegSize == 8 ? X86::ROL8rCL : | 
 |                         (RegSize == 16 ? X86::ROL16rCL : X86::ROL32rCL); | 
 |           BuildMI(BB, Opc, 1, DestReg).addReg(Reg); | 
 |           return true; | 
 |         } else if (RegSize != 8) { | 
 |           unsigned AReg, BReg; | 
 |           if (getRegPressure(ShlVal) > getRegPressure(ShrVal)) { | 
 |             AReg = SelectExpr(ShlVal); | 
 |             BReg = SelectExpr(ShrVal); | 
 |           } else { | 
 |             BReg = SelectExpr(ShrVal); | 
 |             AReg = SelectExpr(ShlVal); | 
 |           } | 
 |           unsigned ShAmt = SelectExpr(ShlAmt); | 
 |           BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt); | 
 |           unsigned Opc = RegSize == 16 ? X86::SHLD16rrCL : X86::SHLD32rrCL; | 
 |           BuildMI(BB, Opc, 2, DestReg).addReg(AReg).addReg(BReg); | 
 |           return true; | 
 |         } | 
 |       } | 
 |  | 
 |   if (ConstantSDNode *ShrCst = dyn_cast<ConstantSDNode>(ShrAmt)) | 
 |     if (ConstantSDNode *ShlCst = dyn_cast<ConstantSDNode>(ShlAmt)) | 
 |       if (ShrCst->getValue() < RegSize && ShlCst->getValue() < RegSize) | 
 |         if (ShrCst->getValue() == RegSize-ShlCst->getValue()) { | 
 |           // (A >> 5) | (A << 27) --> ROR A, 5 | 
 |           // (A >> 5) | (B << 27) --> SHRD A, B, 5 | 
 |           if (ShrVal == ShlVal) { | 
 |             unsigned Reg = SelectExpr(ShrVal); | 
 |             unsigned Opc = RegSize == 8 ? X86::ROR8ri : | 
 |               (RegSize == 16 ? X86::ROR16ri : X86::ROR32ri); | 
 |             BuildMI(BB, Opc, 2, DestReg).addReg(Reg).addImm(ShrCst->getValue()); | 
 |             return true; | 
 |           } else if (RegSize != 8) { | 
 |             unsigned AReg, BReg; | 
 |             if (getRegPressure(ShlVal) > getRegPressure(ShrVal)) { | 
 |               BReg = SelectExpr(ShlVal); | 
 |               AReg = SelectExpr(ShrVal); | 
 |             } else { | 
 |               AReg = SelectExpr(ShrVal); | 
 |               BReg = SelectExpr(ShlVal); | 
 |             } | 
 |             unsigned Opc = RegSize == 16 ? X86::SHRD16rri8 : X86::SHRD32rri8; | 
 |             BuildMI(BB, Opc, 3, DestReg).addReg(AReg).addReg(BReg) | 
 |               .addImm(ShrCst->getValue()); | 
 |             return true; | 
 |           } | 
 |         } | 
 |  | 
 |   return false; | 
 | } | 
 |  | 
 | unsigned ISel::SelectExpr(SDOperand N) { | 
 |   unsigned Result; | 
 |   unsigned Tmp1, Tmp2, Tmp3; | 
 |   unsigned Opc = 0; | 
 |   SDNode *Node = N.Val; | 
 |   SDOperand Op0, Op1; | 
 |  | 
 |   if (Node->getOpcode() == ISD::CopyFromReg) { | 
 |     // FIXME: Handle copy from physregs! | 
 |  | 
 |     // Just use the specified register as our input. | 
 |     return dyn_cast<RegSDNode>(Node)->getReg(); | 
 |   } | 
 |  | 
 |   unsigned &Reg = ExprMap[N]; | 
 |   if (Reg) return Reg; | 
 |  | 
 |   switch (N.getOpcode()) { | 
 |   default: | 
 |     Reg = Result = (N.getValueType() != MVT::Other) ? | 
 |                             MakeReg(N.getValueType()) : 1; | 
 |     break; | 
 |   case ISD::CALL: | 
 |     // If this is a call instruction, make sure to prepare ALL of the result | 
 |     // values as well as the chain. | 
 |     if (Node->getNumValues() == 1) | 
 |       Reg = Result = 1;  // Void call, just a chain. | 
 |     else { | 
 |       Result = MakeReg(Node->getValueType(0)); | 
 |       ExprMap[N.getValue(0)] = Result; | 
 |       for (unsigned i = 1, e = N.Val->getNumValues()-1; i != e; ++i) | 
 |         ExprMap[N.getValue(i)] = MakeReg(Node->getValueType(i)); | 
 |       ExprMap[SDOperand(Node, Node->getNumValues()-1)] = 1; | 
 |     } | 
 |     break; | 
 |   case ISD::ADD_PARTS: | 
 |   case ISD::SUB_PARTS: | 
 |   case ISD::SHL_PARTS: | 
 |   case ISD::SRL_PARTS: | 
 |   case ISD::SRA_PARTS: | 
 |     Result = MakeReg(Node->getValueType(0)); | 
 |     ExprMap[N.getValue(0)] = Result; | 
 |     for (unsigned i = 1, e = N.Val->getNumValues(); i != e; ++i) | 
 |       ExprMap[N.getValue(i)] = MakeReg(Node->getValueType(i)); | 
 |     break; | 
 |   } | 
 |  | 
 |   switch (N.getOpcode()) { | 
 |   default: | 
 |     Node->dump(); | 
 |     assert(0 && "Node not handled!\n"); | 
 |   case ISD::FrameIndex: | 
 |     Tmp1 = cast<FrameIndexSDNode>(N)->getIndex(); | 
 |     addFrameReference(BuildMI(BB, X86::LEA32r, 4, Result), (int)Tmp1); | 
 |     return Result; | 
 |   case ISD::ConstantPool: | 
 |     Tmp1 = cast<ConstantPoolSDNode>(N)->getIndex(); | 
 |     addConstantPoolReference(BuildMI(BB, X86::LEA32r, 4, Result), Tmp1); | 
 |     return Result; | 
 |   case ISD::ConstantFP: | 
 |     ContainsFPCode = true; | 
 |     Tmp1 = Result;   // Intermediate Register | 
 |     if (cast<ConstantFPSDNode>(N)->getValue() < 0.0 || | 
 |         cast<ConstantFPSDNode>(N)->isExactlyValue(-0.0)) | 
 |       Tmp1 = MakeReg(MVT::f64); | 
 |  | 
 |     if (cast<ConstantFPSDNode>(N)->isExactlyValue(+0.0) || | 
 |         cast<ConstantFPSDNode>(N)->isExactlyValue(-0.0)) | 
 |       BuildMI(BB, X86::FLD0, 0, Tmp1); | 
 |     else if (cast<ConstantFPSDNode>(N)->isExactlyValue(+1.0) || | 
 |              cast<ConstantFPSDNode>(N)->isExactlyValue(-1.0)) | 
 |       BuildMI(BB, X86::FLD1, 0, Tmp1); | 
 |     else | 
 |       assert(0 && "Unexpected constant!"); | 
 |     if (Tmp1 != Result) | 
 |       BuildMI(BB, X86::FCHS, 1, Result).addReg(Tmp1); | 
 |     return Result; | 
 |   case ISD::Constant: | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Cannot use constants of this type!"); | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Opc = X86::MOV8ri;  break; | 
 |     case MVT::i16: Opc = X86::MOV16ri; break; | 
 |     case MVT::i32: Opc = X86::MOV32ri; break; | 
 |     } | 
 |     BuildMI(BB, Opc, 1,Result).addImm(cast<ConstantSDNode>(N)->getValue()); | 
 |     return Result; | 
 |   case ISD::UNDEF: | 
 |     if (Node->getValueType(0) == MVT::f64) { | 
 |       // FIXME: SHOULD TEACH STACKIFIER ABOUT UNDEF VALUES! | 
 |       BuildMI(BB, X86::FLD0, 0, Result); | 
 |     } else { | 
 |       BuildMI(BB, X86::IMPLICIT_DEF, 0, Result); | 
 |     } | 
 |     return Result; | 
 |   case ISD::GlobalAddress: { | 
 |     GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal(); | 
 |     BuildMI(BB, X86::MOV32ri, 1, Result).addGlobalAddress(GV); | 
 |     return Result; | 
 |   } | 
 |   case ISD::ExternalSymbol: { | 
 |     const char *Sym = cast<ExternalSymbolSDNode>(N)->getSymbol(); | 
 |     BuildMI(BB, X86::MOV32ri, 1, Result).addExternalSymbol(Sym); | 
 |     return Result; | 
 |   } | 
 |   case ISD::ZERO_EXTEND: { | 
 |     int DestIs16 = N.getValueType() == MVT::i16; | 
 |     int SrcIs16  = N.getOperand(0).getValueType() == MVT::i16; | 
 |  | 
 |     // FIXME: This hack is here for zero extension casts from bool to i8.  This | 
 |     // would not be needed if bools were promoted by Legalize. | 
 |     if (N.getValueType() == MVT::i8) { | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       BuildMI(BB, X86::MOV8rr, 1, Result).addReg(Tmp1); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     if (isFoldableLoad(N.getOperand(0), SDOperand())) { | 
 |       static const unsigned Opc[3] = { | 
 |         X86::MOVZX32rm8, X86::MOVZX32rm16, X86::MOVZX16rm8 | 
 |       }; | 
 |  | 
 |       X86AddressMode AM; | 
 |       EmitFoldedLoad(N.getOperand(0), AM); | 
 |       addFullAddress(BuildMI(BB, Opc[SrcIs16+DestIs16*2], 4, Result), AM); | 
 |  | 
 |       return Result; | 
 |     } | 
 |  | 
 |     static const unsigned Opc[3] = { | 
 |       X86::MOVZX32rr8, X86::MOVZX32rr16, X86::MOVZX16rr8 | 
 |     }; | 
 |     Tmp1 = SelectExpr(N.getOperand(0)); | 
 |     BuildMI(BB, Opc[SrcIs16+DestIs16*2], 1, Result).addReg(Tmp1); | 
 |     return Result; | 
 |   } | 
 |   case ISD::SIGN_EXTEND: { | 
 |     int DestIs16 = N.getValueType() == MVT::i16; | 
 |     int SrcIs16  = N.getOperand(0).getValueType() == MVT::i16; | 
 |  | 
 |     // FIXME: Legalize should promote bools to i8! | 
 |     assert(N.getOperand(0).getValueType() != MVT::i1 && | 
 |            "Sign extend from bool not implemented!"); | 
 |  | 
 |     if (isFoldableLoad(N.getOperand(0), SDOperand())) { | 
 |       static const unsigned Opc[3] = { | 
 |         X86::MOVSX32rm8, X86::MOVSX32rm16, X86::MOVSX16rm8 | 
 |       }; | 
 |  | 
 |       X86AddressMode AM; | 
 |       EmitFoldedLoad(N.getOperand(0), AM); | 
 |       addFullAddress(BuildMI(BB, Opc[SrcIs16+DestIs16*2], 4, Result), AM); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     static const unsigned Opc[3] = { | 
 |       X86::MOVSX32rr8, X86::MOVSX32rr16, X86::MOVSX16rr8 | 
 |     }; | 
 |     Tmp1 = SelectExpr(N.getOperand(0)); | 
 |     BuildMI(BB, Opc[SrcIs16+DestIs16*2], 1, Result).addReg(Tmp1); | 
 |     return Result; | 
 |   } | 
 |   case ISD::TRUNCATE: | 
 |     // Fold TRUNCATE (LOAD P) into a smaller load from P. | 
 |     // FIXME: This should be performed by the DAGCombiner. | 
 |     if (isFoldableLoad(N.getOperand(0), SDOperand())) { | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Unknown truncate!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8:  Opc = X86::MOV8rm;  break; | 
 |       case MVT::i16: Opc = X86::MOV16rm; break; | 
 |       } | 
 |       X86AddressMode AM; | 
 |       EmitFoldedLoad(N.getOperand(0), AM); | 
 |       addFullAddress(BuildMI(BB, Opc, 4, Result), AM); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     // Handle cast of LARGER int to SMALLER int using a move to EAX followed by | 
 |     // a move out of AX or AL. | 
 |     switch (N.getOperand(0).getValueType()) { | 
 |     default: assert(0 && "Unknown truncate!"); | 
 |     case MVT::i8:  Tmp2 = X86::AL;  Opc = X86::MOV8rr;  break; | 
 |     case MVT::i16: Tmp2 = X86::AX;  Opc = X86::MOV16rr; break; | 
 |     case MVT::i32: Tmp2 = X86::EAX; Opc = X86::MOV32rr; break; | 
 |     } | 
 |     Tmp1 = SelectExpr(N.getOperand(0)); | 
 |     BuildMI(BB, Opc, 1, Tmp2).addReg(Tmp1); | 
 |  | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Unknown truncate!"); | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Tmp2 = X86::AL;  Opc = X86::MOV8rr;  break; | 
 |     case MVT::i16: Tmp2 = X86::AX;  Opc = X86::MOV16rr; break; | 
 |     } | 
 |     BuildMI(BB, Opc, 1, Result).addReg(Tmp2); | 
 |     return Result; | 
 |  | 
 |   case ISD::SINT_TO_FP: | 
 |   case ISD::UINT_TO_FP: { | 
 |     // FIXME: Most of this grunt work should be done by legalize! | 
 |     ContainsFPCode = true; | 
 |  | 
 |     // Promote the integer to a type supported by FLD.  We do this because there | 
 |     // are no unsigned FLD instructions, so we must promote an unsigned value to | 
 |     // a larger signed value, then use FLD on the larger value. | 
 |     // | 
 |     MVT::ValueType PromoteType = MVT::Other; | 
 |     MVT::ValueType SrcTy = N.getOperand(0).getValueType(); | 
 |     unsigned PromoteOpcode = 0; | 
 |     unsigned RealDestReg = Result; | 
 |     switch (SrcTy) { | 
 |     case MVT::i1: | 
 |     case MVT::i8: | 
 |       // We don't have the facilities for directly loading byte sized data from | 
 |       // memory (even signed).  Promote it to 16 bits. | 
 |       PromoteType = MVT::i16; | 
 |       PromoteOpcode = Node->getOpcode() == ISD::SINT_TO_FP ? | 
 |         X86::MOVSX16rr8 : X86::MOVZX16rr8; | 
 |       break; | 
 |     case MVT::i16: | 
 |       if (Node->getOpcode() == ISD::UINT_TO_FP) { | 
 |         PromoteType = MVT::i32; | 
 |         PromoteOpcode = X86::MOVZX32rr16; | 
 |       } | 
 |       break; | 
 |     default: | 
 |       // Don't fild into the real destination. | 
 |       if (Node->getOpcode() == ISD::UINT_TO_FP) | 
 |         Result = MakeReg(Node->getValueType(0)); | 
 |       break; | 
 |     } | 
 |  | 
 |     Tmp1 = SelectExpr(N.getOperand(0));  // Get the operand register | 
 |  | 
 |     if (PromoteType != MVT::Other) { | 
 |       Tmp2 = MakeReg(PromoteType); | 
 |       BuildMI(BB, PromoteOpcode, 1, Tmp2).addReg(Tmp1); | 
 |       SrcTy = PromoteType; | 
 |       Tmp1 = Tmp2; | 
 |     } | 
 |  | 
 |     // Spill the integer to memory and reload it from there. | 
 |     unsigned Size = MVT::getSizeInBits(SrcTy)/8; | 
 |     MachineFunction *F = BB->getParent(); | 
 |     int FrameIdx = F->getFrameInfo()->CreateStackObject(Size, Size); | 
 |  | 
 |     switch (SrcTy) { | 
 |     case MVT::i32: | 
 |       addFrameReference(BuildMI(BB, X86::MOV32mr, 5), | 
 |                         FrameIdx).addReg(Tmp1); | 
 |       addFrameReference(BuildMI(BB, X86::FILD32m, 5, Result), FrameIdx); | 
 |       break; | 
 |     case MVT::i16: | 
 |       addFrameReference(BuildMI(BB, X86::MOV16mr, 5), | 
 |                         FrameIdx).addReg(Tmp1); | 
 |       addFrameReference(BuildMI(BB, X86::FILD16m, 5, Result), FrameIdx); | 
 |       break; | 
 |     default: break; // No promotion required. | 
 |     } | 
 |  | 
 |     if (Node->getOpcode() == ISD::UINT_TO_FP && Result != RealDestReg) { | 
 |       // If this is a cast from uint -> double, we need to be careful when if | 
 |       // the "sign" bit is set.  If so, we don't want to make a negative number, | 
 |       // we want to make a positive number.  Emit code to add an offset if the | 
 |       // sign bit is set. | 
 |  | 
 |       // Compute whether the sign bit is set by shifting the reg right 31 bits. | 
 |       unsigned IsNeg = MakeReg(MVT::i32); | 
 |       BuildMI(BB, X86::SHR32ri, 2, IsNeg).addReg(Tmp1).addImm(31); | 
 |  | 
 |       // Create a CP value that has the offset in one word and 0 in the other. | 
 |       static ConstantInt *TheOffset = ConstantUInt::get(Type::ULongTy, | 
 |                                                         0x4f80000000000000ULL); | 
 |       unsigned CPI = F->getConstantPool()->getConstantPoolIndex(TheOffset); | 
 |       BuildMI(BB, X86::FADD32m, 5, RealDestReg).addReg(Result) | 
 |         .addConstantPoolIndex(CPI).addZImm(4).addReg(IsNeg).addSImm(0); | 
 |     } | 
 |     return RealDestReg; | 
 |   } | 
 |   case ISD::FP_TO_SINT: | 
 |   case ISD::FP_TO_UINT: { | 
 |     // FIXME: Most of this grunt work should be done by legalize! | 
 |     Tmp1 = SelectExpr(N.getOperand(0));  // Get the operand register | 
 |  | 
 |     // Change the floating point control register to use "round towards zero" | 
 |     // mode when truncating to an integer value. | 
 |     // | 
 |     MachineFunction *F = BB->getParent(); | 
 |     int CWFrameIdx = F->getFrameInfo()->CreateStackObject(2, 2); | 
 |     addFrameReference(BuildMI(BB, X86::FNSTCW16m, 4), CWFrameIdx); | 
 |  | 
 |     // Load the old value of the high byte of the control word... | 
 |     unsigned HighPartOfCW = MakeReg(MVT::i8); | 
 |     addFrameReference(BuildMI(BB, X86::MOV8rm, 4, HighPartOfCW), | 
 |                       CWFrameIdx, 1); | 
 |  | 
 |     // Set the high part to be round to zero... | 
 |     addFrameReference(BuildMI(BB, X86::MOV8mi, 5), | 
 |                       CWFrameIdx, 1).addImm(12); | 
 |  | 
 |     // Reload the modified control word now... | 
 |     addFrameReference(BuildMI(BB, X86::FLDCW16m, 4), CWFrameIdx); | 
 |  | 
 |     // Restore the memory image of control word to original value | 
 |     addFrameReference(BuildMI(BB, X86::MOV8mr, 5), | 
 |                       CWFrameIdx, 1).addReg(HighPartOfCW); | 
 |  | 
 |     // We don't have the facilities for directly storing byte sized data to | 
 |     // memory.  Promote it to 16 bits.  We also must promote unsigned values to | 
 |     // larger classes because we only have signed FP stores. | 
 |     MVT::ValueType StoreClass = Node->getValueType(0); | 
 |     if (StoreClass == MVT::i8 || Node->getOpcode() == ISD::FP_TO_UINT) | 
 |       switch (StoreClass) { | 
 |       case MVT::i1: | 
 |       case MVT::i8:  StoreClass = MVT::i16; break; | 
 |       case MVT::i16: StoreClass = MVT::i32; break; | 
 |       case MVT::i32: StoreClass = MVT::i64; break; | 
 |       default: assert(0 && "Unknown store class!"); | 
 |       } | 
 |  | 
 |     // Spill the integer to memory and reload it from there. | 
 |     unsigned Size = MVT::getSizeInBits(StoreClass)/8; | 
 |     int FrameIdx = F->getFrameInfo()->CreateStackObject(Size, Size); | 
 |  | 
 |     switch (StoreClass) { | 
 |     default: assert(0 && "Unknown store class!"); | 
 |     case MVT::i16: | 
 |       addFrameReference(BuildMI(BB, X86::FIST16m, 5), FrameIdx).addReg(Tmp1); | 
 |       break; | 
 |     case MVT::i32: | 
 |       addFrameReference(BuildMI(BB, X86::FIST32m, 5), FrameIdx).addReg(Tmp1); | 
 |       break; | 
 |     case MVT::i64: | 
 |       addFrameReference(BuildMI(BB, X86::FISTP64m, 5), FrameIdx).addReg(Tmp1); | 
 |       break;    } | 
 |  | 
 |     switch (Node->getValueType(0)) { | 
 |     default: | 
 |       assert(0 && "Unknown integer type!"); | 
 |     case MVT::i32: | 
 |       addFrameReference(BuildMI(BB, X86::MOV32rm, 4, Result), FrameIdx); | 
 |       break; | 
 |     case MVT::i16: | 
 |       addFrameReference(BuildMI(BB, X86::MOV16rm, 4, Result), FrameIdx); | 
 |       break; | 
 |     case MVT::i8: | 
 |     case MVT::i1: | 
 |       addFrameReference(BuildMI(BB, X86::MOV8rm, 4, Result), FrameIdx); | 
 |       break; | 
 |     } | 
 |  | 
 |     // Reload the original control word now. | 
 |     addFrameReference(BuildMI(BB, X86::FLDCW16m, 4), CWFrameIdx); | 
 |     return Result; | 
 |   } | 
 |   case ISD::ADD: | 
 |     Op0 = N.getOperand(0); | 
 |     Op1 = N.getOperand(1); | 
 |  | 
 |     if (isFoldableLoad(Op0, Op1, true)) { | 
 |       std::swap(Op0, Op1); | 
 |       goto FoldAdd; | 
 |     } | 
 |  | 
 |     if (isFoldableLoad(Op1, Op0, true)) { | 
 |     FoldAdd: | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Cannot add this type!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8:  Opc = X86::ADD8rm;  break; | 
 |       case MVT::i16: Opc = X86::ADD16rm; break; | 
 |       case MVT::i32: Opc = X86::ADD32rm; break; | 
 |       case MVT::f64: | 
 |         // For F64, handle promoted load operations (from F32) as well! | 
 |         Opc = Op1.getOpcode() == ISD::LOAD ? X86::FADD64m : X86::FADD32m; | 
 |         break; | 
 |       } | 
 |       X86AddressMode AM; | 
 |       EmitFoldedLoad(Op1, AM); | 
 |       Tmp1 = SelectExpr(Op0); | 
 |       addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     // See if we can codegen this as an LEA to fold operations together. | 
 |     if (N.getValueType() == MVT::i32) { | 
 |       ExprMap.erase(N); | 
 |       X86ISelAddressMode AM; | 
 |       MatchAddress(N, AM); | 
 |       ExprMap[N] = Result; | 
 |  | 
 |       // If this is not just an add, emit the LEA.  For a simple add (like | 
 |       // reg+reg or reg+imm), we just emit an add.  It might be a good idea to | 
 |       // leave this as LEA, then peephole it to 'ADD' after two address elim | 
 |       // happens. | 
 |       if (AM.Scale != 1 || AM.BaseType == X86ISelAddressMode::FrameIndexBase|| | 
 |           AM.GV || (AM.Base.Reg.Val && AM.IndexReg.Val && AM.Disp)) { | 
 |         X86AddressMode XAM = SelectAddrExprs(AM); | 
 |         addFullAddress(BuildMI(BB, X86::LEA32r, 4, Result), XAM); | 
 |         return Result; | 
 |       } | 
 |     } | 
 |  | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) { | 
 |       Opc = 0; | 
 |       if (CN->getValue() == 1) {   // add X, 1 -> inc X | 
 |         switch (N.getValueType()) { | 
 |         default: assert(0 && "Cannot integer add this type!"); | 
 |         case MVT::i8:  Opc = X86::INC8r; break; | 
 |         case MVT::i16: Opc = X86::INC16r; break; | 
 |         case MVT::i32: Opc = X86::INC32r; break; | 
 |         } | 
 |       } else if (CN->isAllOnesValue()) { // add X, -1 -> dec X | 
 |         switch (N.getValueType()) { | 
 |         default: assert(0 && "Cannot integer add this type!"); | 
 |         case MVT::i8:  Opc = X86::DEC8r; break; | 
 |         case MVT::i16: Opc = X86::DEC16r; break; | 
 |         case MVT::i32: Opc = X86::DEC32r; break; | 
 |         } | 
 |       } | 
 |  | 
 |       if (Opc) { | 
 |         Tmp1 = SelectExpr(Op0); | 
 |         BuildMI(BB, Opc, 1, Result).addReg(Tmp1); | 
 |         return Result; | 
 |       } | 
 |  | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Cannot add this type!"); | 
 |       case MVT::i8:  Opc = X86::ADD8ri; break; | 
 |       case MVT::i16: Opc = X86::ADD16ri; break; | 
 |       case MVT::i32: Opc = X86::ADD32ri; break; | 
 |       } | 
 |       if (Opc) { | 
 |         Tmp1 = SelectExpr(Op0); | 
 |         BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue()); | 
 |         return Result; | 
 |       } | 
 |     } | 
 |  | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Cannot add this type!"); | 
 |     case MVT::i8:  Opc = X86::ADD8rr; break; | 
 |     case MVT::i16: Opc = X86::ADD16rr; break; | 
 |     case MVT::i32: Opc = X86::ADD32rr; break; | 
 |     case MVT::f64: Opc = X86::FpADD; break; | 
 |     } | 
 |  | 
 |     if (getRegPressure(Op0) > getRegPressure(Op1)) { | 
 |       Tmp1 = SelectExpr(Op0); | 
 |       Tmp2 = SelectExpr(Op1); | 
 |     } else { | 
 |       Tmp2 = SelectExpr(Op1); | 
 |       Tmp1 = SelectExpr(Op0); | 
 |     } | 
 |  | 
 |     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2); | 
 |     return Result; | 
 |  | 
 |   case ISD::FABS: | 
 |   case ISD::FNEG: | 
 |   case ISD::FSIN: | 
 |   case ISD::FCOS: | 
 |   case ISD::FSQRT: | 
 |     assert(N.getValueType()==MVT::f64 && "Illegal type for this operation"); | 
 |     Tmp1 = SelectExpr(Node->getOperand(0)); | 
 |     switch (N.getOpcode()) { | 
 |     default: assert(0 && "Unreachable!"); | 
 |     case ISD::FABS: BuildMI(BB, X86::FABS, 1, Result).addReg(Tmp1); break; | 
 |     case ISD::FNEG: BuildMI(BB, X86::FCHS, 1, Result).addReg(Tmp1); break; | 
 |     case ISD::FSQRT: BuildMI(BB, X86::FSQRT, 1, Result).addReg(Tmp1); break; | 
 |     case ISD::FSIN: BuildMI(BB, X86::FSIN, 1, Result).addReg(Tmp1); break; | 
 |     case ISD::FCOS: BuildMI(BB, X86::FCOS, 1, Result).addReg(Tmp1); break; | 
 |     } | 
 |     return Result; | 
 |  | 
 |   case ISD::MULHU: | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Unsupported VT!"); | 
 |     case MVT::i8:  Tmp2 = X86::MUL8r;  break; | 
 |     case MVT::i16: Tmp2 = X86::MUL16r;  break; | 
 |     case MVT::i32: Tmp2 = X86::MUL32r;  break; | 
 |     } | 
 |     // FALL THROUGH | 
 |   case ISD::MULHS: { | 
 |     unsigned MovOpc, LowReg, HiReg; | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Unsupported VT!"); | 
 |     case MVT::i8: | 
 |       MovOpc = X86::MOV8rr; | 
 |       LowReg = X86::AL; | 
 |       HiReg = X86::AH; | 
 |       Opc = X86::IMUL8r; | 
 |       break; | 
 |     case MVT::i16: | 
 |       MovOpc = X86::MOV16rr; | 
 |       LowReg = X86::AX; | 
 |       HiReg = X86::DX; | 
 |       Opc = X86::IMUL16r; | 
 |       break; | 
 |     case MVT::i32: | 
 |       MovOpc = X86::MOV32rr; | 
 |       LowReg = X86::EAX; | 
 |       HiReg = X86::EDX; | 
 |       Opc = X86::IMUL32r; | 
 |       break; | 
 |     } | 
 |     if (Node->getOpcode() != ISD::MULHS) | 
 |       Opc = Tmp2;  // Get the MULHU opcode. | 
 |  | 
 |     Op0 = Node->getOperand(0); | 
 |     Op1 = Node->getOperand(1); | 
 |     if (getRegPressure(Op0) > getRegPressure(Op1)) { | 
 |       Tmp1 = SelectExpr(Op0); | 
 |       Tmp2 = SelectExpr(Op1); | 
 |     } else { | 
 |       Tmp2 = SelectExpr(Op1); | 
 |       Tmp1 = SelectExpr(Op0); | 
 |     } | 
 |  | 
 |     // FIXME: Implement folding of loads into the memory operands here! | 
 |     BuildMI(BB, MovOpc, 1, LowReg).addReg(Tmp1); | 
 |     BuildMI(BB, Opc, 1).addReg(Tmp2); | 
 |     BuildMI(BB, MovOpc, 1, Result).addReg(HiReg); | 
 |     return Result; | 
 |   } | 
 |  | 
 |   case ISD::SUB: | 
 |   case ISD::MUL: | 
 |   case ISD::AND: | 
 |   case ISD::OR: | 
 |   case ISD::XOR: { | 
 |     static const unsigned SUBTab[] = { | 
 |       X86::SUB8ri, X86::SUB16ri, X86::SUB32ri, 0, 0, | 
 |       X86::SUB8rm, X86::SUB16rm, X86::SUB32rm, X86::FSUB32m, X86::FSUB64m, | 
 |       X86::SUB8rr, X86::SUB16rr, X86::SUB32rr, X86::FpSUB  , X86::FpSUB, | 
 |     }; | 
 |     static const unsigned MULTab[] = { | 
 |       0, X86::IMUL16rri, X86::IMUL32rri, 0, 0, | 
 |       0, X86::IMUL16rm , X86::IMUL32rm, X86::FMUL32m, X86::FMUL64m, | 
 |       0, X86::IMUL16rr , X86::IMUL32rr, X86::FpMUL  , X86::FpMUL, | 
 |     }; | 
 |     static const unsigned ANDTab[] = { | 
 |       X86::AND8ri, X86::AND16ri, X86::AND32ri, 0, 0, | 
 |       X86::AND8rm, X86::AND16rm, X86::AND32rm, 0, 0, | 
 |       X86::AND8rr, X86::AND16rr, X86::AND32rr, 0, 0, | 
 |     }; | 
 |     static const unsigned ORTab[] = { | 
 |       X86::OR8ri, X86::OR16ri, X86::OR32ri, 0, 0, | 
 |       X86::OR8rm, X86::OR16rm, X86::OR32rm, 0, 0, | 
 |       X86::OR8rr, X86::OR16rr, X86::OR32rr, 0, 0, | 
 |     }; | 
 |     static const unsigned XORTab[] = { | 
 |       X86::XOR8ri, X86::XOR16ri, X86::XOR32ri, 0, 0, | 
 |       X86::XOR8rm, X86::XOR16rm, X86::XOR32rm, 0, 0, | 
 |       X86::XOR8rr, X86::XOR16rr, X86::XOR32rr, 0, 0, | 
 |     }; | 
 |  | 
 |     Op0 = Node->getOperand(0); | 
 |     Op1 = Node->getOperand(1); | 
 |  | 
 |     if (Node->getOpcode() == ISD::OR && Op0.hasOneUse() && Op1.hasOneUse()) | 
 |       if (EmitOrOpOp(Op0, Op1, Result)) // Match SHLD, SHRD, and rotates. | 
 |         return Result; | 
 |  | 
 |     if (Node->getOpcode() == ISD::SUB) | 
 |       if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(0))) | 
 |         if (CN->isNullValue()) {   // 0 - N -> neg N | 
 |           switch (N.getValueType()) { | 
 |           default: assert(0 && "Cannot sub this type!"); | 
 |           case MVT::i1: | 
 |           case MVT::i8:  Opc = X86::NEG8r;  break; | 
 |           case MVT::i16: Opc = X86::NEG16r; break; | 
 |           case MVT::i32: Opc = X86::NEG32r; break; | 
 |           } | 
 |           Tmp1 = SelectExpr(N.getOperand(1)); | 
 |           BuildMI(BB, Opc, 1, Result).addReg(Tmp1); | 
 |           return Result; | 
 |         } | 
 |  | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) { | 
 |       if (CN->isAllOnesValue() && Node->getOpcode() == ISD::XOR) { | 
 |         Opc = 0; | 
 |         switch (N.getValueType()) { | 
 |         default: assert(0 && "Cannot add this type!"); | 
 |         case MVT::i1:  break;  // Not supported, don't invert upper bits! | 
 |         case MVT::i8:  Opc = X86::NOT8r;  break; | 
 |         case MVT::i16: Opc = X86::NOT16r; break; | 
 |         case MVT::i32: Opc = X86::NOT32r; break; | 
 |         } | 
 |         if (Opc) { | 
 |           Tmp1 = SelectExpr(Op0); | 
 |           BuildMI(BB, Opc, 1, Result).addReg(Tmp1); | 
 |           return Result; | 
 |         } | 
 |       } | 
 |  | 
 |       // Fold common multiplies into LEA instructions. | 
 |       if (Node->getOpcode() == ISD::MUL && N.getValueType() == MVT::i32) { | 
 |         switch ((int)CN->getValue()) { | 
 |         default: break; | 
 |         case 3: | 
 |         case 5: | 
 |         case 9: | 
 |           // Remove N from exprmap so SelectAddress doesn't get confused. | 
 |           ExprMap.erase(N); | 
 |           X86AddressMode AM; | 
 |           SelectAddress(N, AM); | 
 |           // Restore it to the map. | 
 |           ExprMap[N] = Result; | 
 |           addFullAddress(BuildMI(BB, X86::LEA32r, 4, Result), AM); | 
 |           return Result; | 
 |         } | 
 |       } | 
 |  | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Cannot xor this type!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8:  Opc = 0; break; | 
 |       case MVT::i16: Opc = 1; break; | 
 |       case MVT::i32: Opc = 2; break; | 
 |       } | 
 |       switch (Node->getOpcode()) { | 
 |       default: assert(0 && "Unreachable!"); | 
 |       case ISD::SUB: Opc = SUBTab[Opc]; break; | 
 |       case ISD::MUL: Opc = MULTab[Opc]; break; | 
 |       case ISD::AND: Opc = ANDTab[Opc]; break; | 
 |       case ISD::OR:  Opc =  ORTab[Opc]; break; | 
 |       case ISD::XOR: Opc = XORTab[Opc]; break; | 
 |       } | 
 |       if (Opc) {  // Can't fold MUL:i8 R, imm | 
 |         Tmp1 = SelectExpr(Op0); | 
 |         BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue()); | 
 |         return Result; | 
 |       } | 
 |     } | 
 |  | 
 |     if (isFoldableLoad(Op0, Op1, true)) | 
 |       if (Node->getOpcode() != ISD::SUB) { | 
 |         std::swap(Op0, Op1); | 
 |         goto FoldOps; | 
 |       } else { | 
 |         // For FP, emit 'reverse' subract, with a memory operand. | 
 |         if (N.getValueType() == MVT::f64) { | 
 |           if (Op0.getOpcode() == ISD::EXTLOAD) | 
 |             Opc = X86::FSUBR32m; | 
 |           else | 
 |             Opc = X86::FSUBR64m; | 
 |  | 
 |           X86AddressMode AM; | 
 |           EmitFoldedLoad(Op0, AM); | 
 |           Tmp1 = SelectExpr(Op1); | 
 |           addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM); | 
 |           return Result; | 
 |         } | 
 |       } | 
 |  | 
 |     if (isFoldableLoad(Op1, Op0, true)) { | 
 |     FoldOps: | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Cannot operate on this type!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8:  Opc = 5; break; | 
 |       case MVT::i16: Opc = 6; break; | 
 |       case MVT::i32: Opc = 7; break; | 
 |         // For F64, handle promoted load operations (from F32) as well! | 
 |       case MVT::f64: Opc = Op1.getOpcode() == ISD::LOAD ? 9 : 8; break; | 
 |       } | 
 |       switch (Node->getOpcode()) { | 
 |       default: assert(0 && "Unreachable!"); | 
 |       case ISD::SUB: Opc = SUBTab[Opc]; break; | 
 |       case ISD::MUL: Opc = MULTab[Opc]; break; | 
 |       case ISD::AND: Opc = ANDTab[Opc]; break; | 
 |       case ISD::OR:  Opc =  ORTab[Opc]; break; | 
 |       case ISD::XOR: Opc = XORTab[Opc]; break; | 
 |       } | 
 |  | 
 |       X86AddressMode AM; | 
 |       EmitFoldedLoad(Op1, AM); | 
 |       Tmp1 = SelectExpr(Op0); | 
 |       if (Opc) { | 
 |         addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM); | 
 |       } else { | 
 |         assert(Node->getOpcode() == ISD::MUL && | 
 |                N.getValueType() == MVT::i8 && "Unexpected situation!"); | 
 |         // Must use the MUL instruction, which forces use of AL. | 
 |         BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(Tmp1); | 
 |         addFullAddress(BuildMI(BB, X86::MUL8m, 1), AM); | 
 |         BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL); | 
 |       } | 
 |       return Result; | 
 |     } | 
 |  | 
 |     if (getRegPressure(Op0) > getRegPressure(Op1)) { | 
 |       Tmp1 = SelectExpr(Op0); | 
 |       Tmp2 = SelectExpr(Op1); | 
 |     } else { | 
 |       Tmp2 = SelectExpr(Op1); | 
 |       Tmp1 = SelectExpr(Op0); | 
 |     } | 
 |  | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Cannot add this type!"); | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Opc = 10; break; | 
 |     case MVT::i16: Opc = 11; break; | 
 |     case MVT::i32: Opc = 12; break; | 
 |     case MVT::f32: Opc = 13; break; | 
 |     case MVT::f64: Opc = 14; break; | 
 |     } | 
 |     switch (Node->getOpcode()) { | 
 |     default: assert(0 && "Unreachable!"); | 
 |     case ISD::SUB: Opc = SUBTab[Opc]; break; | 
 |     case ISD::MUL: Opc = MULTab[Opc]; break; | 
 |     case ISD::AND: Opc = ANDTab[Opc]; break; | 
 |     case ISD::OR:  Opc =  ORTab[Opc]; break; | 
 |     case ISD::XOR: Opc = XORTab[Opc]; break; | 
 |     } | 
 |     if (Opc) { | 
 |       BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2); | 
 |     } else { | 
 |       assert(Node->getOpcode() == ISD::MUL && | 
 |              N.getValueType() == MVT::i8 && "Unexpected situation!"); | 
 |       // Must use the MUL instruction, which forces use of AL. | 
 |       BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(Tmp1); | 
 |       BuildMI(BB, X86::MUL8r, 1).addReg(Tmp2); | 
 |       BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL); | 
 |     } | 
 |     return Result; | 
 |   } | 
 |   case ISD::ADD_PARTS: | 
 |   case ISD::SUB_PARTS: { | 
 |     assert(N.getNumOperands() == 4 && N.getValueType() == MVT::i32 && | 
 |            "Not an i64 add/sub!"); | 
 |     // Emit all of the operands. | 
 |     std::vector<unsigned> InVals; | 
 |     for (unsigned i = 0, e = N.getNumOperands(); i != e; ++i) | 
 |       InVals.push_back(SelectExpr(N.getOperand(i))); | 
 |     if (N.getOpcode() == ISD::ADD_PARTS) { | 
 |       BuildMI(BB, X86::ADD32rr, 2, Result).addReg(InVals[0]).addReg(InVals[2]); | 
 |       BuildMI(BB, X86::ADC32rr,2,Result+1).addReg(InVals[1]).addReg(InVals[3]); | 
 |     } else { | 
 |       BuildMI(BB, X86::SUB32rr, 2, Result).addReg(InVals[0]).addReg(InVals[2]); | 
 |       BuildMI(BB, X86::SBB32rr, 2,Result+1).addReg(InVals[1]).addReg(InVals[3]); | 
 |     } | 
 |     return Result+N.ResNo; | 
 |   } | 
 |  | 
 |   case ISD::SHL_PARTS: | 
 |   case ISD::SRA_PARTS: | 
 |   case ISD::SRL_PARTS: { | 
 |     assert(N.getNumOperands() == 3 && N.getValueType() == MVT::i32 && | 
 |            "Not an i64 shift!"); | 
 |     unsigned ShiftOpLo = SelectExpr(N.getOperand(0)); | 
 |     unsigned ShiftOpHi = SelectExpr(N.getOperand(1)); | 
 |     unsigned TmpReg = MakeReg(MVT::i32); | 
 |     if (N.getOpcode() == ISD::SRA_PARTS) { | 
 |       // If this is a SHR of a Long, then we need to do funny sign extension | 
 |       // stuff.  TmpReg gets the value to use as the high-part if we are | 
 |       // shifting more than 32 bits. | 
 |       BuildMI(BB, X86::SAR32ri, 2, TmpReg).addReg(ShiftOpHi).addImm(31); | 
 |     } else { | 
 |       // Other shifts use a fixed zero value if the shift is more than 32 bits. | 
 |       BuildMI(BB, X86::MOV32ri, 1, TmpReg).addImm(0); | 
 |     } | 
 |  | 
 |     // Initialize CL with the shift amount. | 
 |     unsigned ShiftAmountReg = SelectExpr(N.getOperand(2)); | 
 |     BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShiftAmountReg); | 
 |  | 
 |     unsigned TmpReg2 = MakeReg(MVT::i32); | 
 |     unsigned TmpReg3 = MakeReg(MVT::i32); | 
 |     if (N.getOpcode() == ISD::SHL_PARTS) { | 
 |       // TmpReg2 = shld inHi, inLo | 
 |       BuildMI(BB, X86::SHLD32rrCL, 2,TmpReg2).addReg(ShiftOpHi) | 
 |         .addReg(ShiftOpLo); | 
 |       // TmpReg3 = shl  inLo, CL | 
 |       BuildMI(BB, X86::SHL32rCL, 1, TmpReg3).addReg(ShiftOpLo); | 
 |  | 
 |       // Set the flags to indicate whether the shift was by more than 32 bits. | 
 |       BuildMI(BB, X86::TEST8ri, 2).addReg(X86::CL).addImm(32); | 
 |  | 
 |       // DestHi = (>32) ? TmpReg3 : TmpReg2; | 
 |       BuildMI(BB, X86::CMOVNE32rr, 2, | 
 |               Result+1).addReg(TmpReg2).addReg(TmpReg3); | 
 |       // DestLo = (>32) ? TmpReg : TmpReg3; | 
 |       BuildMI(BB, X86::CMOVNE32rr, 2, | 
 |               Result).addReg(TmpReg3).addReg(TmpReg); | 
 |     } else { | 
 |       // TmpReg2 = shrd inLo, inHi | 
 |       BuildMI(BB, X86::SHRD32rrCL,2,TmpReg2).addReg(ShiftOpLo) | 
 |         .addReg(ShiftOpHi); | 
 |       // TmpReg3 = s[ah]r  inHi, CL | 
 |       BuildMI(BB, N.getOpcode() == ISD::SRA_PARTS ? X86::SAR32rCL | 
 |                                                   : X86::SHR32rCL, 1, TmpReg3) | 
 |         .addReg(ShiftOpHi); | 
 |  | 
 |       // Set the flags to indicate whether the shift was by more than 32 bits. | 
 |       BuildMI(BB, X86::TEST8ri, 2).addReg(X86::CL).addImm(32); | 
 |  | 
 |       // DestLo = (>32) ? TmpReg3 : TmpReg2; | 
 |       BuildMI(BB, X86::CMOVNE32rr, 2, | 
 |               Result).addReg(TmpReg2).addReg(TmpReg3); | 
 |  | 
 |       // DestHi = (>32) ? TmpReg : TmpReg3; | 
 |       BuildMI(BB, X86::CMOVNE32rr, 2, | 
 |               Result+1).addReg(TmpReg3).addReg(TmpReg); | 
 |     } | 
 |     return Result+N.ResNo; | 
 |   } | 
 |  | 
 |   case ISD::SELECT: | 
 |     if (getRegPressure(N.getOperand(1)) > getRegPressure(N.getOperand(2))) { | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |       Tmp3 = SelectExpr(N.getOperand(2)); | 
 |     } else { | 
 |       Tmp3 = SelectExpr(N.getOperand(2)); | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |     } | 
 |     EmitSelectCC(N.getOperand(0), N.getValueType(), Tmp2, Tmp3, Result); | 
 |     return Result; | 
 |  | 
 |   case ISD::SDIV: | 
 |   case ISD::UDIV: | 
 |   case ISD::SREM: | 
 |   case ISD::UREM: { | 
 |     assert((N.getOpcode() != ISD::SREM || MVT::isInteger(N.getValueType())) && | 
 |            "We don't support this operator!"); | 
 |  | 
 |     if (N.getOpcode() == ISD::SDIV) { | 
 |       // We can fold loads into FpDIVs, but not really into any others. | 
 |       if (N.getValueType() == MVT::f64) { | 
 |         // Check for reversed and unreversed DIV. | 
 |         if (isFoldableLoad(N.getOperand(0), N.getOperand(1), true)) { | 
 |           if (N.getOperand(0).getOpcode() == ISD::EXTLOAD) | 
 |             Opc = X86::FDIVR32m; | 
 |           else | 
 |             Opc = X86::FDIVR64m; | 
 |           X86AddressMode AM; | 
 |           EmitFoldedLoad(N.getOperand(0), AM); | 
 |           Tmp1 = SelectExpr(N.getOperand(1)); | 
 |           addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM); | 
 |           return Result; | 
 |         } else if (isFoldableLoad(N.getOperand(1), N.getOperand(0), true) && | 
 |                    N.getOperand(1).getOpcode() == ISD::LOAD) { | 
 |           if (N.getOperand(1).getOpcode() == ISD::EXTLOAD) | 
 |             Opc = X86::FDIV32m; | 
 |           else | 
 |             Opc = X86::FDIV64m; | 
 |           X86AddressMode AM; | 
 |           EmitFoldedLoad(N.getOperand(1), AM); | 
 |           Tmp1 = SelectExpr(N.getOperand(0)); | 
 |           addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM); | 
 |           return Result; | 
 |         } | 
 |       } | 
 |  | 
 |       if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) { | 
 |         // FIXME: These special cases should be handled by the lowering impl! | 
 |         unsigned RHS = CN->getValue(); | 
 |         bool isNeg = false; | 
 |         if ((int)RHS < 0) { | 
 |           isNeg = true; | 
 |           RHS = -RHS; | 
 |         } | 
 |         if (RHS && (RHS & (RHS-1)) == 0) {   // Signed division by power of 2? | 
 |           unsigned Log = log2(RHS); | 
 |           unsigned TmpReg = MakeReg(N.getValueType()); | 
 |           unsigned SAROpc, SHROpc, ADDOpc, NEGOpc; | 
 |           switch (N.getValueType()) { | 
 |           default: assert("Unknown type to signed divide!"); | 
 |           case MVT::i8: | 
 |             SAROpc = X86::SAR8ri; | 
 |             SHROpc = X86::SHR8ri; | 
 |             ADDOpc = X86::ADD8rr; | 
 |             NEGOpc = X86::NEG8r; | 
 |             break; | 
 |           case MVT::i16: | 
 |             SAROpc = X86::SAR16ri; | 
 |             SHROpc = X86::SHR16ri; | 
 |             ADDOpc = X86::ADD16rr; | 
 |             NEGOpc = X86::NEG16r; | 
 |             break; | 
 |           case MVT::i32: | 
 |             SAROpc = X86::SAR32ri; | 
 |             SHROpc = X86::SHR32ri; | 
 |             ADDOpc = X86::ADD32rr; | 
 |             NEGOpc = X86::NEG32r; | 
 |             break; | 
 |           } | 
 |           Tmp1 = SelectExpr(N.getOperand(0)); | 
 |           BuildMI(BB, SAROpc, 2, TmpReg).addReg(Tmp1).addImm(Log-1); | 
 |           unsigned TmpReg2 = MakeReg(N.getValueType()); | 
 |           BuildMI(BB, SHROpc, 2, TmpReg2).addReg(TmpReg).addImm(32-Log); | 
 |           unsigned TmpReg3 = MakeReg(N.getValueType()); | 
 |           BuildMI(BB, ADDOpc, 2, TmpReg3).addReg(Tmp1).addReg(TmpReg2); | 
 |  | 
 |           unsigned TmpReg4 = isNeg ? MakeReg(N.getValueType()) : Result; | 
 |           BuildMI(BB, SAROpc, 2, TmpReg4).addReg(TmpReg3).addImm(Log); | 
 |           if (isNeg) | 
 |             BuildMI(BB, NEGOpc, 1, Result).addReg(TmpReg4); | 
 |           return Result; | 
 |         } | 
 |       } | 
 |     } | 
 |  | 
 |     if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |     } else { | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |     } | 
 |  | 
 |     bool isSigned = N.getOpcode() == ISD::SDIV || N.getOpcode() == ISD::SREM; | 
 |     bool isDiv    = N.getOpcode() == ISD::SDIV || N.getOpcode() == ISD::UDIV; | 
 |     unsigned LoReg, HiReg, DivOpcode, MovOpcode, ClrOpcode, SExtOpcode; | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Cannot sdiv this type!"); | 
 |     case MVT::i8: | 
 |       DivOpcode = isSigned ? X86::IDIV8r : X86::DIV8r; | 
 |       LoReg = X86::AL; | 
 |       HiReg = X86::AH; | 
 |       MovOpcode = X86::MOV8rr; | 
 |       ClrOpcode = X86::MOV8ri; | 
 |       SExtOpcode = X86::CBW; | 
 |       break; | 
 |     case MVT::i16: | 
 |       DivOpcode = isSigned ? X86::IDIV16r : X86::DIV16r; | 
 |       LoReg = X86::AX; | 
 |       HiReg = X86::DX; | 
 |       MovOpcode = X86::MOV16rr; | 
 |       ClrOpcode = X86::MOV16ri; | 
 |       SExtOpcode = X86::CWD; | 
 |       break; | 
 |     case MVT::i32: | 
 |       DivOpcode = isSigned ? X86::IDIV32r : X86::DIV32r; | 
 |       LoReg = X86::EAX; | 
 |       HiReg = X86::EDX; | 
 |       MovOpcode = X86::MOV32rr; | 
 |       ClrOpcode = X86::MOV32ri; | 
 |       SExtOpcode = X86::CDQ; | 
 |       break; | 
 |     case MVT::f64: | 
 |       BuildMI(BB, X86::FpDIV, 2, Result).addReg(Tmp1).addReg(Tmp2); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     // Set up the low part. | 
 |     BuildMI(BB, MovOpcode, 1, LoReg).addReg(Tmp1); | 
 |  | 
 |     if (isSigned) { | 
 |       // Sign extend the low part into the high part. | 
 |       BuildMI(BB, SExtOpcode, 0); | 
 |     } else { | 
 |       // Zero out the high part, effectively zero extending the input. | 
 |       BuildMI(BB, ClrOpcode, 1, HiReg).addImm(0); | 
 |     } | 
 |  | 
 |     // Emit the DIV/IDIV instruction. | 
 |     BuildMI(BB, DivOpcode, 1).addReg(Tmp2); | 
 |  | 
 |     // Get the result of the divide or rem. | 
 |     BuildMI(BB, MovOpcode, 1, Result).addReg(isDiv ? LoReg : HiReg); | 
 |     return Result; | 
 |   } | 
 |  | 
 |   case ISD::SHL: | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) { | 
 |       if (CN->getValue() == 1) {   // X = SHL Y, 1  -> X = ADD Y, Y | 
 |         switch (N.getValueType()) { | 
 |         default: assert(0 && "Cannot shift this type!"); | 
 |         case MVT::i8:  Opc = X86::ADD8rr; break; | 
 |         case MVT::i16: Opc = X86::ADD16rr; break; | 
 |         case MVT::i32: Opc = X86::ADD32rr; break; | 
 |         } | 
 |         Tmp1 = SelectExpr(N.getOperand(0)); | 
 |         BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp1); | 
 |         return Result; | 
 |       } | 
 |  | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Cannot shift this type!"); | 
 |       case MVT::i8:  Opc = X86::SHL8ri; break; | 
 |       case MVT::i16: Opc = X86::SHL16ri; break; | 
 |       case MVT::i32: Opc = X86::SHL32ri; break; | 
 |       } | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue()); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |     } else { | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |     } | 
 |  | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Cannot shift this type!"); | 
 |     case MVT::i8 : Opc = X86::SHL8rCL; break; | 
 |     case MVT::i16: Opc = X86::SHL16rCL; break; | 
 |     case MVT::i32: Opc = X86::SHL32rCL; break; | 
 |     } | 
 |     BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(Tmp2); | 
 |     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2); | 
 |     return Result; | 
 |   case ISD::SRL: | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) { | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Cannot shift this type!"); | 
 |       case MVT::i8:  Opc = X86::SHR8ri; break; | 
 |       case MVT::i16: Opc = X86::SHR16ri; break; | 
 |       case MVT::i32: Opc = X86::SHR32ri; break; | 
 |       } | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue()); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |     } else { | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |     } | 
 |  | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Cannot shift this type!"); | 
 |     case MVT::i8 : Opc = X86::SHR8rCL; break; | 
 |     case MVT::i16: Opc = X86::SHR16rCL; break; | 
 |     case MVT::i32: Opc = X86::SHR32rCL; break; | 
 |     } | 
 |     BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(Tmp2); | 
 |     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2); | 
 |     return Result; | 
 |   case ISD::SRA: | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) { | 
 |       switch (N.getValueType()) { | 
 |       default: assert(0 && "Cannot shift this type!"); | 
 |       case MVT::i8:  Opc = X86::SAR8ri; break; | 
 |       case MVT::i16: Opc = X86::SAR16ri; break; | 
 |       case MVT::i32: Opc = X86::SAR32ri; break; | 
 |       } | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue()); | 
 |       return Result; | 
 |     } | 
 |  | 
 |     if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |     } else { | 
 |       Tmp2 = SelectExpr(N.getOperand(1)); | 
 |       Tmp1 = SelectExpr(N.getOperand(0)); | 
 |     } | 
 |  | 
 |     switch (N.getValueType()) { | 
 |     default: assert(0 && "Cannot shift this type!"); | 
 |     case MVT::i8 : Opc = X86::SAR8rCL; break; | 
 |     case MVT::i16: Opc = X86::SAR16rCL; break; | 
 |     case MVT::i32: Opc = X86::SAR32rCL; break; | 
 |     } | 
 |     BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(Tmp2); | 
 |     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2); | 
 |     return Result; | 
 |  | 
 |   case ISD::SETCC: | 
 |     EmitCMP(N.getOperand(0), N.getOperand(1), Node->hasOneUse()); | 
 |     EmitSetCC(BB, Result, cast<SetCCSDNode>(N)->getCondition(), | 
 |               MVT::isFloatingPoint(N.getOperand(1).getValueType())); | 
 |     return Result; | 
 |   case ISD::LOAD: | 
 |     // Make sure we generate both values. | 
 |     if (Result != 1) {  // Generate the token | 
 |       if (!ExprMap.insert(std::make_pair(N.getValue(1), 1)).second) | 
 |         assert(0 && "Load already emitted!?"); | 
 |     } else | 
 |       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType()); | 
 |  | 
 |     switch (Node->getValueType(0)) { | 
 |     default: assert(0 && "Cannot load this type!"); | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Opc = X86::MOV8rm; break; | 
 |     case MVT::i16: Opc = X86::MOV16rm; break; | 
 |     case MVT::i32: Opc = X86::MOV32rm; break; | 
 |     case MVT::f64: Opc = X86::FLD64m; ContainsFPCode = true; break; | 
 |     } | 
 |  | 
 |     if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(N.getOperand(1))){ | 
 |       Select(N.getOperand(0)); | 
 |       addConstantPoolReference(BuildMI(BB, Opc, 4, Result), CP->getIndex()); | 
 |     } else { | 
 |       X86AddressMode AM; | 
 |  | 
 |       SDOperand Chain   = N.getOperand(0); | 
 |       SDOperand Address = N.getOperand(1); | 
 |       if (getRegPressure(Chain) > getRegPressure(Address)) { | 
 |         Select(Chain); | 
 |         SelectAddress(Address, AM); | 
 |       } else { | 
 |         SelectAddress(Address, AM); | 
 |         Select(Chain); | 
 |       } | 
 |  | 
 |       addFullAddress(BuildMI(BB, Opc, 4, Result), AM); | 
 |     } | 
 |     return Result; | 
 |  | 
 |   case ISD::EXTLOAD:          // Arbitrarily codegen extloads as MOVZX* | 
 |   case ISD::ZEXTLOAD: { | 
 |     // Make sure we generate both values. | 
 |     if (Result != 1) | 
 |       ExprMap[N.getValue(1)] = 1;   // Generate the token | 
 |     else | 
 |       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType()); | 
 |  | 
 |     if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(N.getOperand(1))) | 
 |       if (Node->getValueType(0) == MVT::f64) { | 
 |         assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::f32 && | 
 |                "Bad EXTLOAD!"); | 
 |         addConstantPoolReference(BuildMI(BB, X86::FLD32m, 4, Result), | 
 |                                  CP->getIndex()); | 
 |         return Result; | 
 |       } | 
 |  | 
 |     X86AddressMode AM; | 
 |     if (getRegPressure(Node->getOperand(0)) > | 
 |            getRegPressure(Node->getOperand(1))) { | 
 |       Select(Node->getOperand(0)); // chain | 
 |       SelectAddress(Node->getOperand(1), AM); | 
 |     } else { | 
 |       SelectAddress(Node->getOperand(1), AM); | 
 |       Select(Node->getOperand(0)); // chain | 
 |     } | 
 |  | 
 |     switch (Node->getValueType(0)) { | 
 |     default: assert(0 && "Unknown type to sign extend to."); | 
 |     case MVT::f64: | 
 |       assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::f32 && | 
 |              "Bad EXTLOAD!"); | 
 |       addFullAddress(BuildMI(BB, X86::FLD32m, 5, Result), AM); | 
 |       break; | 
 |     case MVT::i32: | 
 |       switch (cast<MVTSDNode>(Node)->getExtraValueType()) { | 
 |       default: | 
 |         assert(0 && "Bad zero extend!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8: | 
 |         addFullAddress(BuildMI(BB, X86::MOVZX32rm8, 5, Result), AM); | 
 |         break; | 
 |       case MVT::i16: | 
 |         addFullAddress(BuildMI(BB, X86::MOVZX32rm16, 5, Result), AM); | 
 |         break; | 
 |       } | 
 |       break; | 
 |     case MVT::i16: | 
 |       assert(cast<MVTSDNode>(Node)->getExtraValueType() <= MVT::i8 && | 
 |              "Bad zero extend!"); | 
 |       addFullAddress(BuildMI(BB, X86::MOVSX16rm8, 5, Result), AM); | 
 |       break; | 
 |     case MVT::i8: | 
 |       assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::i1 && | 
 |              "Bad zero extend!"); | 
 |       addFullAddress(BuildMI(BB, X86::MOV8rm, 5, Result), AM); | 
 |       break; | 
 |     } | 
 |     return Result; | 
 |   } | 
 |   case ISD::SEXTLOAD: { | 
 |     // Make sure we generate both values. | 
 |     if (Result != 1) | 
 |       ExprMap[N.getValue(1)] = 1;   // Generate the token | 
 |     else | 
 |       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType()); | 
 |  | 
 |     X86AddressMode AM; | 
 |     if (getRegPressure(Node->getOperand(0)) > | 
 |            getRegPressure(Node->getOperand(1))) { | 
 |       Select(Node->getOperand(0)); // chain | 
 |       SelectAddress(Node->getOperand(1), AM); | 
 |     } else { | 
 |       SelectAddress(Node->getOperand(1), AM); | 
 |       Select(Node->getOperand(0)); // chain | 
 |     } | 
 |  | 
 |     switch (Node->getValueType(0)) { | 
 |     case MVT::i8: assert(0 && "Cannot sign extend from bool!"); | 
 |     default: assert(0 && "Unknown type to sign extend to."); | 
 |     case MVT::i32: | 
 |       switch (cast<MVTSDNode>(Node)->getExtraValueType()) { | 
 |       default: | 
 |       case MVT::i1: assert(0 && "Cannot sign extend from bool!"); | 
 |       case MVT::i8: | 
 |         addFullAddress(BuildMI(BB, X86::MOVSX32rm8, 5, Result), AM); | 
 |         break; | 
 |       case MVT::i16: | 
 |         addFullAddress(BuildMI(BB, X86::MOVSX32rm16, 5, Result), AM); | 
 |         break; | 
 |       } | 
 |       break; | 
 |     case MVT::i16: | 
 |       assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::i8 && | 
 |              "Cannot sign extend from bool!"); | 
 |       addFullAddress(BuildMI(BB, X86::MOVSX16rm8, 5, Result), AM); | 
 |       break; | 
 |     } | 
 |     return Result; | 
 |   } | 
 |  | 
 |   case ISD::DYNAMIC_STACKALLOC: | 
 |     // Generate both result values. | 
 |     if (Result != 1) | 
 |       ExprMap[N.getValue(1)] = 1;   // Generate the token | 
 |     else | 
 |       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType()); | 
 |  | 
 |     // FIXME: We are currently ignoring the requested alignment for handling | 
 |     // greater than the stack alignment.  This will need to be revisited at some | 
 |     // point.  Align = N.getOperand(2); | 
 |  | 
 |     if (!isa<ConstantSDNode>(N.getOperand(2)) || | 
 |         cast<ConstantSDNode>(N.getOperand(2))->getValue() != 0) { | 
 |       std::cerr << "Cannot allocate stack object with greater alignment than" | 
 |                 << " the stack alignment yet!"; | 
 |       abort(); | 
 |     } | 
 |  | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) { | 
 |       Select(N.getOperand(0)); | 
 |       BuildMI(BB, X86::SUB32ri, 2, X86::ESP).addReg(X86::ESP) | 
 |         .addImm(CN->getValue()); | 
 |     } else { | 
 |       if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |         Select(N.getOperand(0)); | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |       } else { | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |         Select(N.getOperand(0)); | 
 |       } | 
 |  | 
 |       // Subtract size from stack pointer, thereby allocating some space. | 
 |       BuildMI(BB, X86::SUB32rr, 2, X86::ESP).addReg(X86::ESP).addReg(Tmp1); | 
 |     } | 
 |  | 
 |     // Put a pointer to the space into the result register, by copying the stack | 
 |     // pointer. | 
 |     BuildMI(BB, X86::MOV32rr, 1, Result).addReg(X86::ESP); | 
 |     return Result; | 
 |  | 
 |   case ISD::CALL: | 
 |     // The chain for this call is now lowered. | 
 |     ExprMap.insert(std::make_pair(N.getValue(Node->getNumValues()-1), 1)); | 
 |  | 
 |     if (GlobalAddressSDNode *GASD = | 
 |                dyn_cast<GlobalAddressSDNode>(N.getOperand(1))) { | 
 |       Select(N.getOperand(0)); | 
 |       BuildMI(BB, X86::CALLpcrel32, 1).addGlobalAddress(GASD->getGlobal(),true); | 
 |     } else if (ExternalSymbolSDNode *ESSDN = | 
 |                dyn_cast<ExternalSymbolSDNode>(N.getOperand(1))) { | 
 |       Select(N.getOperand(0)); | 
 |       BuildMI(BB, X86::CALLpcrel32, | 
 |               1).addExternalSymbol(ESSDN->getSymbol(), true); | 
 |     } else { | 
 |       if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |         Select(N.getOperand(0)); | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |       } else { | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |         Select(N.getOperand(0)); | 
 |       } | 
 |  | 
 |       BuildMI(BB, X86::CALL32r, 1).addReg(Tmp1); | 
 |     } | 
 |     switch (Node->getValueType(0)) { | 
 |     default: assert(0 && "Unknown value type for call result!"); | 
 |     case MVT::Other: return 1; | 
 |     case MVT::i1: | 
 |     case MVT::i8: | 
 |       BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL); | 
 |       break; | 
 |     case MVT::i16: | 
 |       BuildMI(BB, X86::MOV16rr, 1, Result).addReg(X86::AX); | 
 |       break; | 
 |     case MVT::i32: | 
 |       BuildMI(BB, X86::MOV32rr, 1, Result).addReg(X86::EAX); | 
 |       if (Node->getValueType(1) == MVT::i32) | 
 |         BuildMI(BB, X86::MOV32rr, 1, Result+1).addReg(X86::EDX); | 
 |       break; | 
 |     case MVT::f64:     // Floating-point return values live in %ST(0) | 
 |       ContainsFPCode = true; | 
 |       BuildMI(BB, X86::FpGETRESULT, 1, Result); | 
 |       break; | 
 |     } | 
 |     return Result+N.ResNo; | 
 |   case ISD::READPORT: | 
 |     // First, determine that the size of the operand falls within the acceptable | 
 |     // range for this architecture. | 
 |     // | 
 |     if (Node->getOperand(1).getValueType() != MVT::i16) { | 
 |       std::cerr << "llvm.readport: Address size is not 16 bits\n"; | 
 |       exit(1); | 
 |     } | 
 |  | 
 |     // Make sure we generate both values. | 
 |     if (Result != 1) {  // Generate the token | 
 |       if (!ExprMap.insert(std::make_pair(N.getValue(1), 1)).second) | 
 |         assert(0 && "readport already emitted!?"); | 
 |     } else | 
 |       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType()); | 
 |      | 
 |     Select(Node->getOperand(0));  // Select the chain. | 
 |  | 
 |     // If the port is a single-byte constant, use the immediate form. | 
 |     if (ConstantSDNode *Port = dyn_cast<ConstantSDNode>(Node->getOperand(1))) | 
 |       if ((Port->getValue() & 255) == Port->getValue()) { | 
 |         switch (Node->getValueType(0)) { | 
 |         case MVT::i8: | 
 |           BuildMI(BB, X86::IN8ri, 1).addImm(Port->getValue()); | 
 |           BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL); | 
 |           return Result; | 
 |         case MVT::i16: | 
 |           BuildMI(BB, X86::IN16ri, 1).addImm(Port->getValue()); | 
 |           BuildMI(BB, X86::MOV16rr, 1, Result).addReg(X86::AX); | 
 |           return Result; | 
 |         case MVT::i32: | 
 |           BuildMI(BB, X86::IN32ri, 1).addImm(Port->getValue()); | 
 |           BuildMI(BB, X86::MOV32rr, 1, Result).addReg(X86::EAX); | 
 |           return Result; | 
 |         default: break; | 
 |         } | 
 |       } | 
 |  | 
 |     // Now, move the I/O port address into the DX register and use the IN | 
 |     // instruction to get the input data. | 
 |     // | 
 |     Tmp1 = SelectExpr(Node->getOperand(1)); | 
 |     BuildMI(BB, X86::MOV16rr, 1, X86::DX).addReg(Tmp1); | 
 |     switch (Node->getValueType(0)) { | 
 |     case MVT::i8: | 
 |       BuildMI(BB, X86::IN8rr, 0); | 
 |       BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL); | 
 |       return Result; | 
 |     case MVT::i16: | 
 |       BuildMI(BB, X86::IN16rr, 0); | 
 |       BuildMI(BB, X86::MOV16rr, 1, Result).addReg(X86::AX); | 
 |       return Result; | 
 |     case MVT::i32: | 
 |       BuildMI(BB, X86::IN32rr, 0); | 
 |       BuildMI(BB, X86::MOV32rr, 1, Result).addReg(X86::EAX); | 
 |       return Result; | 
 |     default: | 
 |       std::cerr << "Cannot do input on this data type"; | 
 |       exit(1); | 
 |     } | 
 |      | 
 |   } | 
 |  | 
 |   return 0; | 
 | } | 
 |  | 
 | /// TryToFoldLoadOpStore - Given a store node, try to fold together a | 
 | /// load/op/store instruction.  If successful return true. | 
 | bool ISel::TryToFoldLoadOpStore(SDNode *Node) { | 
 |   assert(Node->getOpcode() == ISD::STORE && "Can only do this for stores!"); | 
 |   SDOperand Chain  = Node->getOperand(0); | 
 |   SDOperand StVal  = Node->getOperand(1); | 
 |   SDOperand StPtr  = Node->getOperand(2); | 
 |  | 
 |   // The chain has to be a load, the stored value must be an integer binary | 
 |   // operation with one use. | 
 |   if (!StVal.Val->hasOneUse() || StVal.Val->getNumOperands() != 2 || | 
 |       MVT::isFloatingPoint(StVal.getValueType())) | 
 |     return false; | 
 |  | 
 |   // Token chain must either be a factor node or the load to fold. | 
 |   if (Chain.getOpcode() != ISD::LOAD && Chain.getOpcode() != ISD::TokenFactor) | 
 |     return false; | 
 |  | 
 |   SDOperand TheLoad; | 
 |  | 
 |   // Check to see if there is a load from the same pointer that we're storing | 
 |   // to in either operand of the binop. | 
 |   if (StVal.getOperand(0).getOpcode() == ISD::LOAD && | 
 |       StVal.getOperand(0).getOperand(1) == StPtr) | 
 |     TheLoad = StVal.getOperand(0); | 
 |   else if (StVal.getOperand(1).getOpcode() == ISD::LOAD && | 
 |            StVal.getOperand(1).getOperand(1) == StPtr) | 
 |     TheLoad = StVal.getOperand(1); | 
 |   else | 
 |     return false;  // No matching load operand. | 
 |  | 
 |   // We can only fold the load if there are no intervening side-effecting | 
 |   // operations.  This means that the store uses the load as its token chain, or | 
 |   // there are only token factor nodes in between the store and load. | 
 |   if (Chain != TheLoad.getValue(1)) { | 
 |     // Okay, the other option is that we have a store referring to (possibly | 
 |     // nested) token factor nodes.  For now, just try peeking through one level | 
 |     // of token factors to see if this is the case. | 
 |     bool ChainOk = false; | 
 |     if (Chain.getOpcode() == ISD::TokenFactor) { | 
 |       for (unsigned i = 0, e = Chain.getNumOperands(); i != e; ++i) | 
 |         if (Chain.getOperand(i) == TheLoad.getValue(1)) { | 
 |           ChainOk = true; | 
 |           break; | 
 |         } | 
 |     } | 
 |  | 
 |     if (!ChainOk) return false; | 
 |   } | 
 |  | 
 |   if (TheLoad.getOperand(1) != StPtr) | 
 |     return false; | 
 |  | 
 |   // Make sure that one of the operands of the binop is the load, and that the | 
 |   // load folds into the binop. | 
 |   if (((StVal.getOperand(0) != TheLoad || | 
 |         !isFoldableLoad(TheLoad, StVal.getOperand(1))) && | 
 |        (StVal.getOperand(1) != TheLoad || | 
 |         !isFoldableLoad(TheLoad, StVal.getOperand(0))))) | 
 |     return false; | 
 |  | 
 |   // Finally, check to see if this is one of the ops we can handle! | 
 |   static const unsigned ADDTAB[] = { | 
 |     X86::ADD8mi, X86::ADD16mi, X86::ADD32mi, | 
 |     X86::ADD8mr, X86::ADD16mr, X86::ADD32mr, | 
 |   }; | 
 |   static const unsigned SUBTAB[] = { | 
 |     X86::SUB8mi, X86::SUB16mi, X86::SUB32mi, | 
 |     X86::SUB8mr, X86::SUB16mr, X86::SUB32mr, | 
 |   }; | 
 |   static const unsigned ANDTAB[] = { | 
 |     X86::AND8mi, X86::AND16mi, X86::AND32mi, | 
 |     X86::AND8mr, X86::AND16mr, X86::AND32mr, | 
 |   }; | 
 |   static const unsigned ORTAB[] = { | 
 |     X86::OR8mi, X86::OR16mi, X86::OR32mi, | 
 |     X86::OR8mr, X86::OR16mr, X86::OR32mr, | 
 |   }; | 
 |   static const unsigned XORTAB[] = { | 
 |     X86::XOR8mi, X86::XOR16mi, X86::XOR32mi, | 
 |     X86::XOR8mr, X86::XOR16mr, X86::XOR32mr, | 
 |   }; | 
 |   static const unsigned SHLTAB[] = { | 
 |     X86::SHL8mi, X86::SHL16mi, X86::SHL32mi, | 
 |     /*Have to put the reg in CL*/0, 0, 0, | 
 |   }; | 
 |   static const unsigned SARTAB[] = { | 
 |     X86::SAR8mi, X86::SAR16mi, X86::SAR32mi, | 
 |     /*Have to put the reg in CL*/0, 0, 0, | 
 |   }; | 
 |   static const unsigned SHRTAB[] = { | 
 |     X86::SHR8mi, X86::SHR16mi, X86::SHR32mi, | 
 |     /*Have to put the reg in CL*/0, 0, 0, | 
 |   }; | 
 |  | 
 |   const unsigned *TabPtr = 0; | 
 |   switch (StVal.getOpcode()) { | 
 |   default: | 
 |     std::cerr << "CANNOT [mem] op= val: "; | 
 |     StVal.Val->dump(); std::cerr << "\n"; | 
 |   case ISD::MUL: | 
 |   case ISD::SDIV: | 
 |   case ISD::UDIV: | 
 |   case ISD::SREM: | 
 |   case ISD::UREM: return false; | 
 |  | 
 |   case ISD::ADD: TabPtr = ADDTAB; break; | 
 |   case ISD::SUB: TabPtr = SUBTAB; break; | 
 |   case ISD::AND: TabPtr = ANDTAB; break; | 
 |   case ISD:: OR: TabPtr =  ORTAB; break; | 
 |   case ISD::XOR: TabPtr = XORTAB; break; | 
 |   case ISD::SHL: TabPtr = SHLTAB; break; | 
 |   case ISD::SRA: TabPtr = SARTAB; break; | 
 |   case ISD::SRL: TabPtr = SHRTAB; break; | 
 |   } | 
 |  | 
 |   // Handle: [mem] op= CST | 
 |   SDOperand Op0 = StVal.getOperand(0); | 
 |   SDOperand Op1 = StVal.getOperand(1); | 
 |   unsigned Opc = 0; | 
 |   if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) { | 
 |     switch (Op0.getValueType()) { // Use Op0's type because of shifts. | 
 |     default: break; | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Opc = TabPtr[0]; break; | 
 |     case MVT::i16: Opc = TabPtr[1]; break; | 
 |     case MVT::i32: Opc = TabPtr[2]; break; | 
 |     } | 
 |  | 
 |     if (Opc) { | 
 |       if (!ExprMap.insert(std::make_pair(TheLoad.getValue(1), 1)).second) | 
 |         assert(0 && "Already emitted?"); | 
 |       Select(Chain); | 
 |  | 
 |       X86AddressMode AM; | 
 |       if (getRegPressure(TheLoad.getOperand(0)) > | 
 |           getRegPressure(TheLoad.getOperand(1))) { | 
 |         Select(TheLoad.getOperand(0)); | 
 |         SelectAddress(TheLoad.getOperand(1), AM); | 
 |       } else { | 
 |         SelectAddress(TheLoad.getOperand(1), AM); | 
 |         Select(TheLoad.getOperand(0)); | 
 |       } | 
 |  | 
 |       if (StVal.getOpcode() == ISD::ADD) { | 
 |         if (CN->getValue() == 1) { | 
 |           switch (Op0.getValueType()) { | 
 |           default: break; | 
 |           case MVT::i8: | 
 |             addFullAddress(BuildMI(BB, X86::INC8m, 4), AM); | 
 |             return true; | 
 |           case MVT::i16: Opc = TabPtr[1]; | 
 |             addFullAddress(BuildMI(BB, X86::INC16m, 4), AM); | 
 |             return true; | 
 |           case MVT::i32: Opc = TabPtr[2]; | 
 |             addFullAddress(BuildMI(BB, X86::INC32m, 4), AM); | 
 |             return true; | 
 |           } | 
 |         } else if (CN->getValue()+1 == 0) {   // [X] += -1 -> DEC [X] | 
 |           switch (Op0.getValueType()) { | 
 |           default: break; | 
 |           case MVT::i8: | 
 |             addFullAddress(BuildMI(BB, X86::DEC8m, 4), AM); | 
 |             return true; | 
 |           case MVT::i16: Opc = TabPtr[1]; | 
 |             addFullAddress(BuildMI(BB, X86::DEC16m, 4), AM); | 
 |             return true; | 
 |           case MVT::i32: Opc = TabPtr[2]; | 
 |             addFullAddress(BuildMI(BB, X86::DEC32m, 4), AM); | 
 |             return true; | 
 |           } | 
 |         } | 
 |       } | 
 |  | 
 |       addFullAddress(BuildMI(BB, Opc, 4+1),AM).addImm(CN->getValue()); | 
 |       return true; | 
 |     } | 
 |   } | 
 |  | 
 |   // If we have [mem] = V op [mem], try to turn it into: | 
 |   // [mem] = [mem] op V. | 
 |   if (Op1 == TheLoad && StVal.getOpcode() != ISD::SUB && | 
 |       StVal.getOpcode() != ISD::SHL && StVal.getOpcode() != ISD::SRA && | 
 |       StVal.getOpcode() != ISD::SRL) | 
 |     std::swap(Op0, Op1); | 
 |  | 
 |   if (Op0 != TheLoad) return false; | 
 |  | 
 |   switch (Op0.getValueType()) { | 
 |   default: return false; | 
 |   case MVT::i1: | 
 |   case MVT::i8:  Opc = TabPtr[3]; break; | 
 |   case MVT::i16: Opc = TabPtr[4]; break; | 
 |   case MVT::i32: Opc = TabPtr[5]; break; | 
 |   } | 
 |  | 
 |   // Table entry doesn't exist? | 
 |   if (Opc == 0) return false; | 
 |  | 
 |   if (!ExprMap.insert(std::make_pair(TheLoad.getValue(1), 1)).second) | 
 |     assert(0 && "Already emitted?"); | 
 |   Select(Chain); | 
 |   Select(TheLoad.getOperand(0)); | 
 |  | 
 |   X86AddressMode AM; | 
 |   SelectAddress(TheLoad.getOperand(1), AM); | 
 |   unsigned Reg = SelectExpr(Op1); | 
 |   addFullAddress(BuildMI(BB, Opc, 4+1), AM).addReg(Reg); | 
 |   return true; | 
 | } | 
 |  | 
 |  | 
 | void ISel::Select(SDOperand N) { | 
 |   unsigned Tmp1, Tmp2, Opc; | 
 |  | 
 |   if (!ExprMap.insert(std::make_pair(N, 1)).second) | 
 |     return;  // Already selected. | 
 |  | 
 |   SDNode *Node = N.Val; | 
 |  | 
 |   switch (Node->getOpcode()) { | 
 |   default: | 
 |     Node->dump(); std::cerr << "\n"; | 
 |     assert(0 && "Node not handled yet!"); | 
 |   case ISD::EntryToken: return;  // Noop | 
 |   case ISD::TokenFactor: | 
 |     if (Node->getNumOperands() == 2) { | 
 |       bool OneFirst = | 
 |         getRegPressure(Node->getOperand(1))>getRegPressure(Node->getOperand(0)); | 
 |       Select(Node->getOperand(OneFirst)); | 
 |       Select(Node->getOperand(!OneFirst)); | 
 |     } else { | 
 |       std::vector<std::pair<unsigned, unsigned> > OpsP; | 
 |       for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) | 
 |         OpsP.push_back(std::make_pair(getRegPressure(Node->getOperand(i)), i)); | 
 |       std::sort(OpsP.begin(), OpsP.end()); | 
 |       std::reverse(OpsP.begin(), OpsP.end()); | 
 |       for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) | 
 |         Select(Node->getOperand(OpsP[i].second)); | 
 |     } | 
 |     return; | 
 |   case ISD::CopyToReg: | 
 |     if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |       Select(N.getOperand(0)); | 
 |       Tmp1 = SelectExpr(N.getOperand(1)); | 
 |     } else { | 
 |       Tmp1 = SelectExpr(N.getOperand(1)); | 
 |       Select(N.getOperand(0)); | 
 |     } | 
 |     Tmp2 = cast<RegSDNode>(N)->getReg(); | 
 |  | 
 |     if (Tmp1 != Tmp2) { | 
 |       switch (N.getOperand(1).getValueType()) { | 
 |       default: assert(0 && "Invalid type for operation!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8:  Opc = X86::MOV8rr; break; | 
 |       case MVT::i16: Opc = X86::MOV16rr; break; | 
 |       case MVT::i32: Opc = X86::MOV32rr; break; | 
 |       case MVT::f64: Opc = X86::FpMOV; ContainsFPCode = true; break; | 
 |       } | 
 |       BuildMI(BB, Opc, 1, Tmp2).addReg(Tmp1); | 
 |     } | 
 |     return; | 
 |   case ISD::RET: | 
 |     switch (N.getNumOperands()) { | 
 |     default: | 
 |       assert(0 && "Unknown return instruction!"); | 
 |     case 3: | 
 |       assert(N.getOperand(1).getValueType() == MVT::i32 && | 
 | 	     N.getOperand(2).getValueType() == MVT::i32 && | 
 | 	     "Unknown two-register value!"); | 
 |       if (getRegPressure(N.getOperand(1)) > getRegPressure(N.getOperand(2))) { | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |         Tmp2 = SelectExpr(N.getOperand(2)); | 
 |       } else { | 
 |         Tmp2 = SelectExpr(N.getOperand(2)); | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |       } | 
 |       Select(N.getOperand(0)); | 
 |  | 
 |       BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Tmp1); | 
 |       BuildMI(BB, X86::MOV32rr, 1, X86::EDX).addReg(Tmp2); | 
 |       break; | 
 |     case 2: | 
 |       if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |         Select(N.getOperand(0)); | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |       } else { | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |         Select(N.getOperand(0)); | 
 |       } | 
 |       switch (N.getOperand(1).getValueType()) { | 
 |       default: assert(0 && "All other types should have been promoted!!"); | 
 |       case MVT::f64: | 
 | 	BuildMI(BB, X86::FpSETRESULT, 1).addReg(Tmp1); | 
 | 	break; | 
 |       case MVT::i32: | 
 | 	BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Tmp1); | 
 | 	break; | 
 |       } | 
 |       break; | 
 |     case 1: | 
 |       Select(N.getOperand(0)); | 
 |       break; | 
 |     } | 
 |     BuildMI(BB, X86::RET, 0); // Just emit a 'ret' instruction | 
 |     return; | 
 |   case ISD::BR: { | 
 |     Select(N.getOperand(0)); | 
 |     MachineBasicBlock *Dest = | 
 |       cast<BasicBlockSDNode>(N.getOperand(1))->getBasicBlock(); | 
 |     BuildMI(BB, X86::JMP, 1).addMBB(Dest); | 
 |     return; | 
 |   } | 
 |  | 
 |   case ISD::BRCOND: { | 
 |     MachineBasicBlock *Dest = | 
 |       cast<BasicBlockSDNode>(N.getOperand(2))->getBasicBlock(); | 
 |  | 
 |     // Try to fold a setcc into the branch.  If this fails, emit a test/jne | 
 |     // pair. | 
 |     if (EmitBranchCC(Dest, N.getOperand(0), N.getOperand(1))) { | 
 |       if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) { | 
 |         Select(N.getOperand(0)); | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |       } else { | 
 |         Tmp1 = SelectExpr(N.getOperand(1)); | 
 |         Select(N.getOperand(0)); | 
 |       } | 
 |       BuildMI(BB, X86::TEST8rr, 2).addReg(Tmp1).addReg(Tmp1); | 
 |       BuildMI(BB, X86::JNE, 1).addMBB(Dest); | 
 |     } | 
 |  | 
 |     return; | 
 |   } | 
 |  | 
 |   case ISD::LOAD: | 
 |     // If this load could be folded into the only using instruction, and if it | 
 |     // is safe to emit the instruction here, try to do so now. | 
 |     if (Node->hasNUsesOfValue(1, 0)) { | 
 |       SDOperand TheVal = N.getValue(0); | 
 |       SDNode *User = 0; | 
 |       for (SDNode::use_iterator UI = Node->use_begin(); ; ++UI) { | 
 |         assert(UI != Node->use_end() && "Didn't find use!"); | 
 |         SDNode *UN = *UI; | 
 |         for (unsigned i = 0, e = UN->getNumOperands(); i != e; ++i) | 
 |           if (UN->getOperand(i) == TheVal) { | 
 |             User = UN; | 
 |             goto FoundIt; | 
 |           } | 
 |       } | 
 |     FoundIt: | 
 |       // Only handle unary operators right now. | 
 |       if (User->getNumOperands() == 1) { | 
 |         ExprMap.erase(N); | 
 |         SelectExpr(SDOperand(User, 0)); | 
 |         return; | 
 |       } | 
 |     } | 
 |     ExprMap.erase(N); | 
 |     SelectExpr(N); | 
 |     return; | 
 |   case ISD::READPORT: | 
 |   case ISD::EXTLOAD: | 
 |   case ISD::SEXTLOAD: | 
 |   case ISD::ZEXTLOAD: | 
 |   case ISD::CALL: | 
 |   case ISD::DYNAMIC_STACKALLOC: | 
 |     ExprMap.erase(N); | 
 |     SelectExpr(N); | 
 |     return; | 
 |  | 
 |   case ISD::TRUNCSTORE: {  // truncstore chain, val, ptr :storety | 
 |     // On X86, we can represent all types except for Bool and Float natively. | 
 |     X86AddressMode AM; | 
 |     MVT::ValueType StoredTy = cast<MVTSDNode>(Node)->getExtraValueType(); | 
 |     assert((StoredTy == MVT::i1 || StoredTy == MVT::f32 || | 
 |             StoredTy == MVT::i16 /*FIXME: THIS IS JUST FOR TESTING!*/) | 
 |            && "Unsupported TRUNCSTORE for this target!"); | 
 |  | 
 |     if (StoredTy == MVT::i16) { | 
 |       // FIXME: This is here just to allow testing.  X86 doesn't really have a | 
 |       // TRUNCSTORE i16 operation, but this is required for targets that do not | 
 |       // have 16-bit integer registers.  We occasionally disable 16-bit integer | 
 |       // registers to test the promotion code. | 
 |       Select(N.getOperand(0)); | 
 |       Tmp1 = SelectExpr(N.getOperand(1)); | 
 |       SelectAddress(N.getOperand(2), AM); | 
 |  | 
 |       BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Tmp1); | 
 |       addFullAddress(BuildMI(BB, X86::MOV16mr, 5), AM).addReg(X86::AX); | 
 |       return; | 
 |     } | 
 |  | 
 |     // Store of constant bool? | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) { | 
 |       if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(2))) { | 
 |         Select(N.getOperand(0)); | 
 |         SelectAddress(N.getOperand(2), AM); | 
 |       } else { | 
 |         SelectAddress(N.getOperand(2), AM); | 
 |         Select(N.getOperand(0)); | 
 |       } | 
 |       addFullAddress(BuildMI(BB, X86::MOV8mi, 5), AM).addImm(CN->getValue()); | 
 |       return; | 
 |     } | 
 |  | 
 |     switch (StoredTy) { | 
 |     default: assert(0 && "Cannot truncstore this type!"); | 
 |     case MVT::i1: Opc = X86::MOV8mr; break; | 
 |     case MVT::f32: Opc = X86::FST32m; break; | 
 |     } | 
 |  | 
 |     std::vector<std::pair<unsigned, unsigned> > RP; | 
 |     RP.push_back(std::make_pair(getRegPressure(N.getOperand(0)), 0)); | 
 |     RP.push_back(std::make_pair(getRegPressure(N.getOperand(1)), 1)); | 
 |     RP.push_back(std::make_pair(getRegPressure(N.getOperand(2)), 2)); | 
 |     std::sort(RP.begin(), RP.end()); | 
 |  | 
 |     Tmp1 = 0;   // Silence a warning. | 
 |     for (unsigned i = 0; i != 3; ++i) | 
 |       switch (RP[2-i].second) { | 
 |       default: assert(0 && "Unknown operand number!"); | 
 |       case 0: Select(N.getOperand(0)); break; | 
 |       case 1: Tmp1 = SelectExpr(N.getOperand(1)); break; | 
 |       case 2: SelectAddress(N.getOperand(2), AM); break; | 
 |       } | 
 |  | 
 |     addFullAddress(BuildMI(BB, Opc, 4+1), AM).addReg(Tmp1); | 
 |     return; | 
 |   } | 
 |   case ISD::STORE: { | 
 |     X86AddressMode AM; | 
 |  | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) { | 
 |       Opc = 0; | 
 |       switch (CN->getValueType(0)) { | 
 |       default: assert(0 && "Invalid type for operation!"); | 
 |       case MVT::i1: | 
 |       case MVT::i8:  Opc = X86::MOV8mi; break; | 
 |       case MVT::i16: Opc = X86::MOV16mi; break; | 
 |       case MVT::i32: Opc = X86::MOV32mi; break; | 
 |       case MVT::f64: break; | 
 |       } | 
 |       if (Opc) { | 
 |         if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(2))) { | 
 |           Select(N.getOperand(0)); | 
 |           SelectAddress(N.getOperand(2), AM); | 
 |         } else { | 
 |           SelectAddress(N.getOperand(2), AM); | 
 |           Select(N.getOperand(0)); | 
 |         } | 
 |         addFullAddress(BuildMI(BB, Opc, 4+1), AM).addImm(CN->getValue()); | 
 |         return; | 
 |       } | 
 |     } else if (GlobalAddressSDNode *GA = | 
 |                       dyn_cast<GlobalAddressSDNode>(N.getOperand(1))) { | 
 |       assert(GA->getValueType(0) == MVT::i32 && "Bad pointer operand"); | 
 |  | 
 |       if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(2))) { | 
 |         Select(N.getOperand(0)); | 
 |         SelectAddress(N.getOperand(2), AM); | 
 |       } else { | 
 |         SelectAddress(N.getOperand(2), AM); | 
 |         Select(N.getOperand(0)); | 
 |       } | 
 |       addFullAddress(BuildMI(BB, X86::MOV32mi, 4+1), | 
 |                      AM).addGlobalAddress(GA->getGlobal()); | 
 |       return; | 
 |     } | 
 |  | 
 |     // Check to see if this is a load/op/store combination. | 
 |     if (TryToFoldLoadOpStore(Node)) | 
 |       return; | 
 |  | 
 |     switch (N.getOperand(1).getValueType()) { | 
 |     default: assert(0 && "Cannot store this type!"); | 
 |     case MVT::i1: | 
 |     case MVT::i8:  Opc = X86::MOV8mr; break; | 
 |     case MVT::i16: Opc = X86::MOV16mr; break; | 
 |     case MVT::i32: Opc = X86::MOV32mr; break; | 
 |     case MVT::f64: Opc = X86::FST64m; break; | 
 |     } | 
 |  | 
 |     std::vector<std::pair<unsigned, unsigned> > RP; | 
 |     RP.push_back(std::make_pair(getRegPressure(N.getOperand(0)), 0)); | 
 |     RP.push_back(std::make_pair(getRegPressure(N.getOperand(1)), 1)); | 
 |     RP.push_back(std::make_pair(getRegPressure(N.getOperand(2)), 2)); | 
 |     std::sort(RP.begin(), RP.end()); | 
 |  | 
 |     Tmp1 = 0; // Silence a warning. | 
 |     for (unsigned i = 0; i != 3; ++i) | 
 |       switch (RP[2-i].second) { | 
 |       default: assert(0 && "Unknown operand number!"); | 
 |       case 0: Select(N.getOperand(0)); break; | 
 |       case 1: Tmp1 = SelectExpr(N.getOperand(1)); break; | 
 |       case 2: SelectAddress(N.getOperand(2), AM); break; | 
 |       } | 
 |  | 
 |     addFullAddress(BuildMI(BB, Opc, 4+1), AM).addReg(Tmp1); | 
 |     return; | 
 |   } | 
 |   case ISD::ADJCALLSTACKDOWN: | 
 |   case ISD::ADJCALLSTACKUP: | 
 |     Select(N.getOperand(0)); | 
 |     Tmp1 = cast<ConstantSDNode>(N.getOperand(1))->getValue(); | 
 |  | 
 |     Opc = N.getOpcode() == ISD::ADJCALLSTACKDOWN ? X86::ADJCALLSTACKDOWN : | 
 |                                                    X86::ADJCALLSTACKUP; | 
 |     BuildMI(BB, Opc, 1).addImm(Tmp1); | 
 |     return; | 
 |   case ISD::MEMSET: { | 
 |     Select(N.getOperand(0));  // Select the chain. | 
 |     unsigned Align = | 
 |       (unsigned)cast<ConstantSDNode>(Node->getOperand(4))->getValue(); | 
 |     if (Align == 0) Align = 1; | 
 |  | 
 |     // Turn the byte code into # iterations | 
 |     unsigned CountReg; | 
 |     unsigned Opcode; | 
 |     if (ConstantSDNode *ValC = dyn_cast<ConstantSDNode>(Node->getOperand(2))) { | 
 |       unsigned Val = ValC->getValue() & 255; | 
 |  | 
 |       // If the value is a constant, then we can potentially use larger sets. | 
 |       switch (Align & 3) { | 
 |       case 2:   // WORD aligned | 
 |         CountReg = MakeReg(MVT::i32); | 
 |         if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) { | 
 |           BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/2); | 
 |         } else { | 
 |           unsigned ByteReg = SelectExpr(Node->getOperand(3)); | 
 |           BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(1); | 
 |         } | 
 |         BuildMI(BB, X86::MOV16ri, 1, X86::AX).addImm((Val << 8) | Val); | 
 |         Opcode = X86::REP_STOSW; | 
 |         break; | 
 |       case 0:   // DWORD aligned | 
 |         CountReg = MakeReg(MVT::i32); | 
 |         if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) { | 
 |           BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/4); | 
 |         } else { | 
 |           unsigned ByteReg = SelectExpr(Node->getOperand(3)); | 
 |           BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(2); | 
 |         } | 
 |         Val = (Val << 8) | Val; | 
 |         BuildMI(BB, X86::MOV32ri, 1, X86::EAX).addImm((Val << 16) | Val); | 
 |         Opcode = X86::REP_STOSD; | 
 |         break; | 
 |       default:  // BYTE aligned | 
 |         CountReg = SelectExpr(Node->getOperand(3)); | 
 |         BuildMI(BB, X86::MOV8ri, 1, X86::AL).addImm(Val); | 
 |         Opcode = X86::REP_STOSB; | 
 |         break; | 
 |       } | 
 |     } else { | 
 |       // If it's not a constant value we are storing, just fall back.  We could | 
 |       // try to be clever to form 16 bit and 32 bit values, but we don't yet. | 
 |       unsigned ValReg = SelectExpr(Node->getOperand(2)); | 
 |       BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(ValReg); | 
 |       CountReg = SelectExpr(Node->getOperand(3)); | 
 |       Opcode = X86::REP_STOSB; | 
 |     } | 
 |  | 
 |     // No matter what the alignment is, we put the source in ESI, the | 
 |     // destination in EDI, and the count in ECX. | 
 |     unsigned TmpReg1 = SelectExpr(Node->getOperand(1)); | 
 |     BuildMI(BB, X86::MOV32rr, 1, X86::ECX).addReg(CountReg); | 
 |     BuildMI(BB, X86::MOV32rr, 1, X86::EDI).addReg(TmpReg1); | 
 |     BuildMI(BB, Opcode, 0); | 
 |     return; | 
 |   } | 
 |   case ISD::MEMCPY: { | 
 |     Select(N.getOperand(0));  // Select the chain. | 
 |     unsigned Align = | 
 |       (unsigned)cast<ConstantSDNode>(Node->getOperand(4))->getValue(); | 
 |     if (Align == 0) Align = 1; | 
 |  | 
 |     // Turn the byte code into # iterations | 
 |     unsigned CountReg; | 
 |     unsigned Opcode; | 
 |     switch (Align & 3) { | 
 |     case 2:   // WORD aligned | 
 |       CountReg = MakeReg(MVT::i32); | 
 |       if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) { | 
 |         BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/2); | 
 |       } else { | 
 |         unsigned ByteReg = SelectExpr(Node->getOperand(3)); | 
 |         BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(1); | 
 |       } | 
 |       Opcode = X86::REP_MOVSW; | 
 |       break; | 
 |     case 0:   // DWORD aligned | 
 |       CountReg = MakeReg(MVT::i32); | 
 |       if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) { | 
 |         BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/4); | 
 |       } else { | 
 |         unsigned ByteReg = SelectExpr(Node->getOperand(3)); | 
 |         BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(2); | 
 |       } | 
 |       Opcode = X86::REP_MOVSD; | 
 |       break; | 
 |     default:  // BYTE aligned | 
 |       CountReg = SelectExpr(Node->getOperand(3)); | 
 |       Opcode = X86::REP_MOVSB; | 
 |       break; | 
 |     } | 
 |  | 
 |     // No matter what the alignment is, we put the source in ESI, the | 
 |     // destination in EDI, and the count in ECX. | 
 |     unsigned TmpReg1 = SelectExpr(Node->getOperand(1)); | 
 |     unsigned TmpReg2 = SelectExpr(Node->getOperand(2)); | 
 |     BuildMI(BB, X86::MOV32rr, 1, X86::ECX).addReg(CountReg); | 
 |     BuildMI(BB, X86::MOV32rr, 1, X86::EDI).addReg(TmpReg1); | 
 |     BuildMI(BB, X86::MOV32rr, 1, X86::ESI).addReg(TmpReg2); | 
 |     BuildMI(BB, Opcode, 0); | 
 |     return; | 
 |   } | 
 |   case ISD::WRITEPORT: | 
 |     if (Node->getOperand(2).getValueType() != MVT::i16) { | 
 |       std::cerr << "llvm.writeport: Address size is not 16 bits\n"; | 
 |       exit(1); | 
 |     } | 
 |     Select(Node->getOperand(0)); // Emit the chain. | 
 |  | 
 |     Tmp1 = SelectExpr(Node->getOperand(1)); | 
 |     switch (Node->getOperand(1).getValueType()) { | 
 |     case MVT::i8: | 
 |       BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(Tmp1); | 
 |       Tmp2 = X86::OUT8ir;  Opc = X86::OUT8rr; | 
 |       break; | 
 |     case MVT::i16: | 
 |       BuildMI(BB, X86::MOV16rr, 1, X86::AX).addReg(Tmp1); | 
 |       Tmp2 = X86::OUT16ir; Opc = X86::OUT16rr; | 
 |       break; | 
 |     case MVT::i32: | 
 |       BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Tmp1); | 
 |       Tmp2 = X86::OUT32ir; Opc = X86::OUT32rr; | 
 |       break; | 
 |     default: | 
 |       std::cerr << "llvm.writeport: invalid data type for X86 target"; | 
 |       exit(1); | 
 |     } | 
 |  | 
 |     // If the port is a single-byte constant, use the immediate form. | 
 |     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Node->getOperand(2))) | 
 |       if ((CN->getValue() & 255) == CN->getValue()) { | 
 |         BuildMI(BB, Tmp2, 1).addImm(CN->getValue()); | 
 |         return; | 
 |       } | 
 |  | 
 |     // Otherwise, move the I/O port address into the DX register. | 
 |     unsigned Reg = SelectExpr(Node->getOperand(2)); | 
 |     BuildMI(BB, X86::MOV16rr, 1, X86::DX).addReg(Reg); | 
 |     BuildMI(BB, Opc, 0); | 
 |     return; | 
 |   } | 
 |   assert(0 && "Should not be reached!"); | 
 | } | 
 |  | 
 |  | 
 | /// createX86PatternInstructionSelector - This pass converts an LLVM function | 
 | /// into a machine code representation using pattern matching and a machine | 
 | /// description file. | 
 | /// | 
 | FunctionPass *llvm::createX86PatternInstructionSelector(TargetMachine &TM) { | 
 |   return new ISel(TM); | 
 | } |