src/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.h

   1 //===---- InstrEmitter.h - Emit MachineInstrs for the SelectionDAG class ---==//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This declares the Emit routines for the SelectionDAG class, which creates
  11 // MachineInstrs based on the decisions of the SelectionDAG instruction
  12 // selection.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #ifndef INSTREMITTER_H
  17 #define INSTREMITTER_H
  18
  19 #include "llvm/CodeGen/SelectionDAG.h"
  20 #include "llvm/CodeGen/MachineBasicBlock.h"
  21 #include "llvm/ADT/DenseMap.h"
  22
  23 namespace llvm {
  24
  25 class MCInstrDesc;
  26 class SDDbgValue;
  27
  28 class InstrEmitter {
  29   MachineFunction *MF;
  30   MachineRegisterInfo *MRI;
  31   const TargetMachine *TM;
  32   const TargetInstrInfo *TII;
  33   const TargetRegisterInfo *TRI;
  34   const TargetLowering *TLI;
  35
  36   MachineBasicBlock *MBB;
  37   MachineBasicBlock::iterator InsertPos;
  38
  39   /// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an
  40   /// implicit physical register output.
  41   void EmitCopyFromReg(SDNode *Node, unsigned ResNo,
  42                        bool IsClone, bool IsCloned,
  43                        unsigned SrcReg,
  44                        DenseMap<SDValue, unsigned> &VRBaseMap);
  45
  46   /// getDstOfCopyToRegUse - If the only use of the specified result number of
  47   /// node is a CopyToReg, return its destination register. Return 0 otherwise.
  48   unsigned getDstOfOnlyCopyToRegUse(SDNode *Node,
  49                                     unsigned ResNo) const;
  50
  51   void CreateVirtualRegisters(SDNode *Node, MachineInstr *MI,
  52                               const MCInstrDesc &II,
  53                               bool IsClone, bool IsCloned,
  54                               DenseMap<SDValue, unsigned> &VRBaseMap);
  55
  56   /// getVR - Return the virtual register corresponding to the specified result
  57   /// of the specified node.
  58   unsigned getVR(SDValue Op,
  59                  DenseMap<SDValue, unsigned> &VRBaseMap);
  60
  61   /// AddRegisterOperand - Add the specified register as an operand to the
  62   /// specified machine instr. Insert register copies if the register is
  63   /// not in the required register class.
  64   void AddRegisterOperand(MachineInstr *MI, SDValue Op,
  65                           unsigned IIOpNum,
  66                           const MCInstrDesc *II,
  67                           DenseMap<SDValue, unsigned> &VRBaseMap,
  68                           bool IsDebug, bool IsClone, bool IsCloned);
  69
  70   /// AddOperand - Add the specified operand to the specified machine instr.  II
  71   /// specifies the instruction information for the node, and IIOpNum is the
  72   /// operand number (in the II) that we are adding. IIOpNum and II are used for
  73   /// assertions only.
  74   void AddOperand(MachineInstr *MI, SDValue Op,
  75                   unsigned IIOpNum,
  76                   const MCInstrDesc *II,
  77                   DenseMap<SDValue, unsigned> &VRBaseMap,
  78                   bool IsDebug, bool IsClone, bool IsCloned);
  79
  80   /// ConstrainForSubReg - Try to constrain VReg to a register class that
  81   /// supports SubIdx sub-registers.  Emit a copy if that isn't possible.
  82   /// Return the virtual register to use.
  83   unsigned ConstrainForSubReg(unsigned VReg, unsigned SubIdx,
  84                               EVT VT, DebugLoc DL);
  85
  86   /// EmitSubregNode - Generate machine code for subreg nodes.
  87   ///
  88   void EmitSubregNode(SDNode *Node, DenseMap<SDValue, unsigned> &VRBaseMap,
  89                       bool IsClone, bool IsCloned);
  90
  91   /// EmitCopyToRegClassNode - Generate machine code for COPY_TO_REGCLASS nodes.
  92   /// COPY_TO_REGCLASS is just a normal copy, except that the destination
  93   /// register is constrained to be in a particular register class.
  94   ///
  95   void EmitCopyToRegClassNode(SDNode *Node,
  96                               DenseMap<SDValue, unsigned> &VRBaseMap);
  97
  98   /// EmitRegSequence - Generate machine code for REG_SEQUENCE nodes.
  99   ///
 100   void EmitRegSequence(SDNode *Node, DenseMap<SDValue, unsigned> &VRBaseMap,
 101                        bool IsClone, bool IsCloned);
 102 public:
 103   /// CountResults - The results of target nodes have register or immediate
 104   /// operands first, then an optional chain, and optional flag operands
 105   /// (which do not go into the machine instrs.)
 106   static unsigned CountResults(SDNode *Node);
 107
 108   /// EmitDbgValue - Generate machine instruction for a dbg_value node.
 109   ///
 110   MachineInstr *EmitDbgValue(SDDbgValue *SD,
 111                              DenseMap<SDValue, unsigned> &VRBaseMap);
 112
 113   /// EmitNode - Generate machine code for a node and needed dependencies.
 114   ///
 115   void EmitNode(SDNode *Node, bool IsClone, bool IsCloned,
 116                 DenseMap<SDValue, unsigned> &VRBaseMap) {
 117     if (Node->isMachineOpcode())
 118       EmitMachineNode(Node, IsClone, IsCloned, VRBaseMap);
 119     else
 120       EmitSpecialNode(Node, IsClone, IsCloned, VRBaseMap);
 121   }
 122
 123   /// getBlock - Return the current basic block.
 124   MachineBasicBlock *getBlock() { return MBB; }
 125
 126   /// getInsertPos - Return the current insertion position.
 127   MachineBasicBlock::iterator getInsertPos() { return InsertPos; }
 128
 129   /// InstrEmitter - Construct an InstrEmitter and set it to start inserting
 130   /// at the given position in the given block.
 131   InstrEmitter(MachineBasicBlock *mbb, MachineBasicBlock::iterator insertpos);
 132
 133 private:
 134   void EmitMachineNode(SDNode *Node, bool IsClone, bool IsCloned,
 135                        DenseMap<SDValue, unsigned> &VRBaseMap);
 136   void EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
 137                        DenseMap<SDValue, unsigned> &VRBaseMap);
 138 };
 139
 140 }
 141
 142 #endif