//===- MipsInstrInfo.h - Mips Instruction Information -----------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the Mips implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//

#ifndef MIPSINSTRUCTIONINFO_H
#define MIPSINSTRUCTIONINFO_H

#include "Mips.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "MipsRegisterInfo.h"

#define GET_INSTRINFO_HEADER
#include "MipsGenInstrInfo.inc"

namespace llvm {

namespace Mips {
  /// GetOppositeBranchOpc - Return the inverse of the specified
  /// opcode, e.g. turning BEQ to BNE.
  unsigned GetOppositeBranchOpc(unsigned Opc);
}

/// MipsII - This namespace holds all of the target specific flags that
/// instruction info tracks.
///
namespace MipsII {
  /// Target Operand Flag enum.
  enum TOF {
    //===------------------------------------------------------------------===//
    // Mips Specific MachineOperand flags.

    MO_NO_FLAG,

    /// MO_GOT - Represents the offset into the global offset table at which
    /// the address the relocation entry symbol resides during execution.
    MO_GOT,

    /// MO_GOT_CALL - Represents the offset into the global offset table at
    /// which the address of a call site relocation entry symbol resides
    /// during execution. This is different from the above since this flag
    /// can only be present in call instructions.
    MO_GOT_CALL,

    /// MO_GPREL - Represents the offset from the current gp value to be used
    /// for the relocatable object file being produced.
    MO_GPREL,

    /// MO_ABS_HI/LO - Represents the hi or low part of an absolute symbol
    /// address.
    MO_ABS_HI,
    MO_ABS_LO,

    /// MO_TLSGD - Represents the offset into the global offset table at which
    // the module ID and TSL block offset reside during execution (General
    // Dynamic TLS).
    MO_TLSGD,

    /// MO_GOTTPREL - Represents the offset from the thread pointer (Initial
    // Exec TLS).
    MO_GOTTPREL,

    /// MO_TPREL_HI/LO - Represents the hi and low part of the offset from
    // the thread pointer (Local Exec TLS).
    MO_TPREL_HI,
    MO_TPREL_LO,

    // N32/64 Flags.
    MO_GPOFF_HI,
    MO_GPOFF_LO,
    MO_GOT_DISP,
    MO_GOT_PAGE,
    MO_GOT_OFST
  };

  enum {
    //===------------------------------------------------------------------===//
    // Instruction encodings.  These are the standard/most common forms for
    // Mips instructions.
    //

    // Pseudo - This represents an instruction that is a pseudo instruction
    // or one that has not been implemented yet.  It is illegal to code generate
    // it, but tolerated for intermediate implementation stages.
    Pseudo   = 0,

    /// FrmR - This form is for instructions of the format R.
    FrmR  = 1,
    /// FrmI - This form is for instructions of the format I.
    FrmI  = 2,
    /// FrmJ - This form is for instructions of the format J.
    FrmJ  = 3,
    /// FrmFR - This form is for instructions of the format FR.
    FrmFR = 4,
    /// FrmFI - This form is for instructions of the format FI.
    FrmFI = 5,
    /// FrmOther - This form is for instructions that have no specific format.
    FrmOther = 6,

    FormMask = 15
  };
}

class MipsInstrInfo : public MipsGenInstrInfo {
  MipsTargetMachine &TM;
  const MipsRegisterInfo RI;
public:
  explicit MipsInstrInfo(MipsTargetMachine &TM);

  /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
  /// such, whenever a client has an instance of instruction info, it should
  /// always be able to get register info as well (through this method).
  ///
  virtual const MipsRegisterInfo &getRegisterInfo() const;

  /// isLoadFromStackSlot - If the specified machine instruction is a direct
  /// load from a stack slot, return the virtual or physical register number of
  /// the destination along with the FrameIndex of the loaded stack slot.  If
  /// not, return 0.  This predicate must return 0 if the instruction has
  /// any side effects other than loading from the stack slot.
  virtual unsigned isLoadFromStackSlot(const MachineInstr *MI,
                                       int &FrameIndex) const;

  /// isStoreToStackSlot - If the specified machine instruction is a direct
  /// store to a stack slot, return the virtual or physical register number of
  /// the source reg along with the FrameIndex of the loaded stack slot.  If
  /// not, return 0.  This predicate must return 0 if the instruction has
  /// any side effects other than storing to the stack slot.
  virtual unsigned isStoreToStackSlot(const MachineInstr *MI,
                                      int &FrameIndex) const;

  /// Branch Analysis
  virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
                             MachineBasicBlock *&FBB,
                             SmallVectorImpl<MachineOperand> &Cond,
                             bool AllowModify) const;
  virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;

private:
  void BuildCondBr(MachineBasicBlock &MBB, MachineBasicBlock *TBB, DebugLoc DL,
                   const SmallVectorImpl<MachineOperand>& Cond) const;

public:
  virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
                                MachineBasicBlock *FBB,
                                const SmallVectorImpl<MachineOperand> &Cond,
                                DebugLoc DL) const;
  virtual void copyPhysReg(MachineBasicBlock &MBB,
                           MachineBasicBlock::iterator MI, DebugLoc DL,
                           unsigned DestReg, unsigned SrcReg,
                           bool KillSrc) const;
  virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator MBBI,
                                   unsigned SrcReg, bool isKill, int FrameIndex,
                                   const TargetRegisterClass *RC,
                                   const TargetRegisterInfo *TRI) const;

  virtual void loadRegFromStackSlot(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MBBI,
                                    unsigned DestReg, int FrameIndex,
                                    const TargetRegisterClass *RC,
                                    const TargetRegisterInfo *TRI) const;

  virtual MachineInstr* emitFrameIndexDebugValue(MachineFunction &MF,
                                                 int FrameIx, uint64_t Offset,
                                                 const MDNode *MDPtr,
                                                 DebugLoc DL) const;

  virtual
  bool ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const;

  /// Insert nop instruction when hazard condition is found
  virtual void insertNoop(MachineBasicBlock &MBB,
                          MachineBasicBlock::iterator MI) const;

  /// getGlobalBaseReg - Return a virtual register initialized with the
  /// the global base register value. Output instructions required to
  /// initialize the register in the function entry block, if necessary.
  ///
  unsigned getGlobalBaseReg(MachineFunction *MF) const;
};

}

#endif
