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//===-- llvm/CodeGen/SelectionDAGISel.h - Common Base Class------*- C++ -*-===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file implements the SelectionDAGISel class, which is used as the common
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// base class for SelectionDAG-based instruction selectors.
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_SELECTIONDAG_ISEL_H
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#define LLVM_CODEGEN_SELECTIONDAG_ISEL_H
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#include "llvm/BasicBlock.h"
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#include "llvm/Pass.h"
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#include "llvm/CodeGen/SelectionDAG.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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class SelectionDAGBuilder;
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class MachineRegisterInfo;
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class MachineBasicBlock;
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class MachineFunction;
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class TargetInstrInfo;
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class FunctionLoweringInfo;
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class ScheduleHazardRecognizer;
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class ScheduleDAGSDNodes;
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/// SelectionDAGISel - This is the common base class used for SelectionDAG-based
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/// pattern-matching instruction selectors.
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class SelectionDAGISel : public MachineFunctionPass {
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const TargetMachine &TM;
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const TargetLowering &TLI;
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FunctionLoweringInfo *FuncInfo;
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MachineRegisterInfo *RegInfo;
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SelectionDAGBuilder *SDB;
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CodeGenOpt::Level OptLevel;
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explicit SelectionDAGISel(const TargetMachine &tm,
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CodeGenOpt::Level OL = CodeGenOpt::Default);
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virtual ~SelectionDAGISel();
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const TargetLowering &getTargetLowering() { return TLI; }
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virtual void getAnalysisUsage(AnalysisUsage &AU) const;
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virtual bool runOnMachineFunction(MachineFunction &MF);
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virtual void EmitFunctionEntryCode() {}
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/// PreprocessISelDAG - This hook allows targets to hack on the graph before
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/// instruction selection starts.
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virtual void PreprocessISelDAG() {}
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/// PostprocessISelDAG() - This hook allows the target to hack on the graph
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/// right after selection.
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virtual void PostprocessISelDAG() {}
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/// Select - Main hook targets implement to select a node.
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virtual SDNode *Select(SDNode *N) = 0;
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/// SelectInlineAsmMemoryOperand - Select the specified address as a target
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/// addressing mode, according to the specified constraint code. If this does
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/// not match or is not implemented, return true. The resultant operands
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/// (which will appear in the machine instruction) should be added to the
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virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
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std::vector<SDValue> &OutOps) {
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/// IsProfitableToFold - Returns true if it's profitable to fold the specific
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/// operand node N of U during instruction selection that starts at Root.
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virtual bool IsProfitableToFold(SDValue N, SDNode *U, SDNode *Root) const;
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/// IsLegalToFold - Returns true if the specific operand node N of
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/// U can be folded during instruction selection that starts at Root.
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/// FIXME: This is a static member function because the PIC16 target,
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/// which uses it during lowering.
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static bool IsLegalToFold(SDValue N, SDNode *U, SDNode *Root,
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CodeGenOpt::Level OptLevel,
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bool IgnoreChains = false);
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/// CreateTargetHazardRecognizer - Return a newly allocated hazard recognizer
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/// to use for this target when scheduling the DAG.
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virtual ScheduleHazardRecognizer *CreateTargetHazardRecognizer();
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// Opcodes used by the DAG state machine:
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enum BuiltinOpcodes {
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OPC_RecordChild0, OPC_RecordChild1, OPC_RecordChild2, OPC_RecordChild3,
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OPC_RecordChild4, OPC_RecordChild5, OPC_RecordChild6, OPC_RecordChild7,
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OPC_CaptureFlagInput,
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OPC_CheckPatternPredicate,
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OPC_CheckChild0Type, OPC_CheckChild1Type, OPC_CheckChild2Type,
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OPC_CheckChild3Type, OPC_CheckChild4Type, OPC_CheckChild5Type,
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OPC_CheckChild6Type, OPC_CheckChild7Type,
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OPC_CheckAndImm, OPC_CheckOrImm,
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OPC_CheckFoldableChainNode,
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OPC_EmitConvertToTarget,
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OPC_EmitMergeInputChains,
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OPC_EmitMergeInputChains1_0,
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OPC_EmitMergeInputChains1_1,
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OPFL_None = 0, // Node has no chain or flag input and isn't variadic.
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OPFL_Chain = 1, // Node has a chain input.
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OPFL_FlagInput = 2, // Node has a flag input.
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OPFL_FlagOutput = 4, // Node has a flag output.
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OPFL_MemRefs = 8, // Node gets accumulated MemRefs.
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OPFL_Variadic0 = 1<<4, // Node is variadic, root has 0 fixed inputs.
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OPFL_Variadic1 = 2<<4, // Node is variadic, root has 1 fixed inputs.
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OPFL_Variadic2 = 3<<4, // Node is variadic, root has 2 fixed inputs.
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OPFL_Variadic3 = 4<<4, // Node is variadic, root has 3 fixed inputs.
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OPFL_Variadic4 = 5<<4, // Node is variadic, root has 4 fixed inputs.
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OPFL_Variadic5 = 6<<4, // Node is variadic, root has 5 fixed inputs.
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OPFL_Variadic6 = 7<<4, // Node is variadic, root has 6 fixed inputs.
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OPFL_VariadicInfo = OPFL_Variadic6
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/// getNumFixedFromVariadicInfo - Transform an EmitNode flags word into the
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/// number of fixed arity values that should be skipped when copying from the
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static inline int getNumFixedFromVariadicInfo(unsigned Flags) {
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return ((Flags&OPFL_VariadicInfo) >> 4)-1;
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/// DAGSize - Size of DAG being instruction selected.
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/// ISelPosition - Node iterator marking the current position of
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/// instruction selection as it procedes through the topologically-sorted
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SelectionDAG::allnodes_iterator ISelPosition;
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/// ISelUpdater - helper class to handle updates of the
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/// instruction selection graph.
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class ISelUpdater : public SelectionDAG::DAGUpdateListener {
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SelectionDAG::allnodes_iterator &ISelPosition;
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explicit ISelUpdater(SelectionDAG::allnodes_iterator &isp)
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: ISelPosition(isp) {}
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/// NodeDeleted - Handle nodes deleted from the graph. If the
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/// node being deleted is the current ISelPosition node, update
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virtual void NodeDeleted(SDNode *N, SDNode *E) {
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if (ISelPosition == SelectionDAG::allnodes_iterator(N))
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/// NodeUpdated - Ignore updates for now.
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virtual void NodeUpdated(SDNode *N) {}
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/// ReplaceUses - replace all uses of the old node F with the use
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/// of the new node T.
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void ReplaceUses(SDValue F, SDValue T) {
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ISelUpdater ISU(ISelPosition);
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CurDAG->ReplaceAllUsesOfValueWith(F, T, &ISU);
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/// ReplaceUses - replace all uses of the old nodes F with the use
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/// of the new nodes T.
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void ReplaceUses(const SDValue *F, const SDValue *T, unsigned Num) {
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ISelUpdater ISU(ISelPosition);
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CurDAG->ReplaceAllUsesOfValuesWith(F, T, Num, &ISU);
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/// ReplaceUses - replace all uses of the old node F with the use
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/// of the new node T.
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void ReplaceUses(SDNode *F, SDNode *T) {
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ISelUpdater ISU(ISelPosition);
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CurDAG->ReplaceAllUsesWith(F, T, &ISU);
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/// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
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/// by tblgen. Others should not call it.
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void SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops);
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// Calls to these predicates are generated by tblgen.
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bool CheckAndMask(SDValue LHS, ConstantSDNode *RHS,
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int64_t DesiredMaskS) const;
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bool CheckOrMask(SDValue LHS, ConstantSDNode *RHS,
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int64_t DesiredMaskS) const;
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/// CheckPatternPredicate - This function is generated by tblgen in the
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/// target. It runs the specified pattern predicate and returns true if it
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/// succeeds or false if it fails. The number is a private implementation
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/// detail to the code tblgen produces.
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virtual bool CheckPatternPredicate(unsigned PredNo) const {
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assert(0 && "Tblgen should generate the implementation of this!");
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/// CheckNodePredicate - This function is generated by tblgen in the target.
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/// It runs node predicate number PredNo and returns true if it succeeds or
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/// false if it fails. The number is a private implementation
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/// detail to the code tblgen produces.
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virtual bool CheckNodePredicate(SDNode *N, unsigned PredNo) const {
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assert(0 && "Tblgen should generate the implementation of this!");
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virtual bool CheckComplexPattern(SDNode *Root, SDValue N, unsigned PatternNo,
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SmallVectorImpl<SDValue> &Result) {
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assert(0 && "Tblgen should generate the implementation of this!");
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virtual SDValue RunSDNodeXForm(SDValue V, unsigned XFormNo) {
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assert(0 && "Tblgen shoudl generate this!");
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SDNode *SelectCodeCommon(SDNode *NodeToMatch,
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const unsigned char *MatcherTable,
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// Calls to these functions are generated by tblgen.
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SDNode *Select_INLINEASM(SDNode *N);
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SDNode *Select_UNDEF(SDNode *N);
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void CannotYetSelect(SDNode *N);
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void DoInstructionSelection();
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SDNode *MorphNode(SDNode *Node, unsigned TargetOpc, SDVTList VTs,
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const SDValue *Ops, unsigned NumOps, unsigned EmitNodeInfo);
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void PrepareEHLandingPad();
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void SelectAllBasicBlocks(const Function &Fn);
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void FinishBasicBlock();
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void SelectBasicBlock(BasicBlock::const_iterator Begin,
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BasicBlock::const_iterator End,
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void CodeGenAndEmitDAG();
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void LowerArguments(const BasicBlock *BB);
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void ComputeLiveOutVRegInfo();
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/// Create the scheduler. If a specific scheduler was specified
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/// via the SchedulerRegistry, use it, otherwise select the
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/// one preferred by the target.
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ScheduleDAGSDNodes *CreateScheduler();
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/// OpcodeOffset - This is a cache used to dispatch efficiently into isel
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/// state machines that start with a OPC_SwitchOpcode node.
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std::vector<unsigned> OpcodeOffset;
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void UpdateChainsAndFlags(SDNode *NodeToMatch, SDValue InputChain,
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const SmallVectorImpl<SDNode*> &ChainNodesMatched,
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SDValue InputFlag,const SmallVectorImpl<SDNode*> &F,
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#endif /* LLVM_CODEGEN_SELECTIONDAG_ISEL_H */