//===-- CodeGen/MachineInstBuilder.h - Simplify creation of MIs -*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file exposes a function named BuildMI, which is useful for dramatically
// simplifying how MachineInstr's are created.  It allows use of code like this:
//
//   M = BuildMI(X86::ADDrr8, 2).addReg(argVal1).addReg(argVal2);
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_MACHINEINSTRBUILDER_H
#define LLVM_CODEGEN_MACHINEINSTRBUILDER_H

#include "llvm/CodeGen/MachineFunction.h"

namespace llvm {

class TargetInstrDesc;

namespace RegState {
  enum {
    Define         = 0x2,
    Implicit       = 0x4,
    Kill           = 0x8,
    Dead           = 0x10,
    EarlyClobber   = 0x20,
    ImplicitDefine = Implicit | Define,
    ImplicitKill   = Implicit | Kill
  };
}

class MachineInstrBuilder {
  MachineInstr *MI;
public:
  explicit MachineInstrBuilder(MachineInstr *mi) : MI(mi) {}

  /// Allow automatic conversion to the machine instruction we are working on.
  ///
  operator MachineInstr*() const { return MI; }
  operator MachineBasicBlock::iterator() const { return MI; }

  /// addReg - Add a new virtual register operand...
  ///
  const
  MachineInstrBuilder &addReg(unsigned RegNo, unsigned flags = 0,
                              unsigned SubReg = 0) const {
    assert((flags & 0x1) == 0 &&
           "Passing in 'true' to addReg is forbidden! Use enums instead.");
    MI->addOperand(MachineOperand::CreateReg(RegNo,
                                             flags & RegState::Define,
                                             flags & RegState::Implicit,
                                             flags & RegState::Kill,
                                             flags & RegState::Dead,
                                             SubReg,
                                             flags & RegState::EarlyClobber));
    return *this;
  }

  /// addImm - Add a new immediate operand.
  ///
  const MachineInstrBuilder &addImm(int64_t Val) const {
    MI->addOperand(MachineOperand::CreateImm(Val));
    return *this;
  }

  const MachineInstrBuilder &addFPImm(const ConstantFP *Val) const {
    MI->addOperand(MachineOperand::CreateFPImm(Val));
    return *this;
  }

  const MachineInstrBuilder &addMBB(MachineBasicBlock *MBB) const {
    MI->addOperand(MachineOperand::CreateMBB(MBB));
    return *this;
  }

  const MachineInstrBuilder &addFrameIndex(unsigned Idx) const {
    MI->addOperand(MachineOperand::CreateFI(Idx));
    return *this;
  }

  const MachineInstrBuilder &addConstantPoolIndex(unsigned Idx,
                                                  int Offset = 0) const {
    MI->addOperand(MachineOperand::CreateCPI(Idx, Offset));
    return *this;
  }

  const MachineInstrBuilder &addJumpTableIndex(unsigned Idx) const {
    MI->addOperand(MachineOperand::CreateJTI(Idx));
    return *this;
  }

  const MachineInstrBuilder &addGlobalAddress(GlobalValue *GV,
                                              int64_t Offset = 0) const {
    MI->addOperand(MachineOperand::CreateGA(GV, Offset));
    return *this;
  }

  const MachineInstrBuilder &addExternalSymbol(const char *FnName,
                                               int64_t Offset = 0) const {
    MI->addOperand(MachineOperand::CreateES(FnName, Offset));
    return *this;
  }

  const MachineInstrBuilder &addMemOperand(const MachineMemOperand &MMO) const {
    MI->addMemOperand(*MI->getParent()->getParent(), MMO);
    return *this;
  }

  const MachineInstrBuilder &addOperand(const MachineOperand &MO) const {
    if (MO.isReg())
      return addReg(MO.getReg(),
                    (MO.isDef() ? RegState::Define : 0) |
                    (MO.isImplicit() ? RegState::Implicit : 0) |
                    (MO.isKill() ? RegState::Kill : 0) |
                    (MO.isDead() ? RegState::Dead : 0) |
                    (MO.isEarlyClobber() ? RegState::EarlyClobber : 0),
                    MO.getSubReg());
    if (MO.isImm())
      return addImm(MO.getImm());
    if (MO.isFI())
      return addFrameIndex(MO.getIndex());
    if (MO.isGlobal())
      return addGlobalAddress(MO.getGlobal(), MO.getOffset());
    if (MO.isCPI())
      return addConstantPoolIndex(MO.getIndex(), MO.getOffset());
    if (MO.isSymbol())
      return addExternalSymbol(MO.getSymbolName());
    if (MO.isJTI())
      return addJumpTableIndex(MO.getIndex());

    assert(0 && "Unknown operand for MachineInstrBuilder::AddOperand!");
    return *this;
  }
};

/// BuildMI - Builder interface.  Specify how to create the initial instruction
/// itself.
///
inline MachineInstrBuilder BuildMI(MachineFunction &MF,
                                   DebugLoc DL,
                                   const TargetInstrDesc &TID) {
  return MachineInstrBuilder(MF.CreateMachineInstr(TID, DL));
}

/// BuildMI - This version of the builder sets up the first operand as a
/// destination virtual register.
///
inline MachineInstrBuilder BuildMI(MachineFunction &MF,
                                   DebugLoc DL,
                                   const TargetInstrDesc &TID,
                                   unsigned DestReg) {
  return MachineInstrBuilder(MF.CreateMachineInstr(TID, DL))
           .addReg(DestReg, RegState::Define);
}

/// BuildMI - This version of the builder inserts the newly-built
/// instruction before the given position in the given MachineBasicBlock, and
/// sets up the first operand as a destination virtual register.
///
inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
                                   MachineBasicBlock::iterator I,
                                   DebugLoc DL,
                                   const TargetInstrDesc &TID,
                                   unsigned DestReg) {
  MachineInstr *MI = BB.getParent()->CreateMachineInstr(TID, DL);
  BB.insert(I, MI);
  return MachineInstrBuilder(MI).addReg(DestReg, RegState::Define);
}

/// BuildMI - This version of the builder inserts the newly-built
/// instruction before the given position in the given MachineBasicBlock, and
/// does NOT take a destination register.
///
inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
                                   MachineBasicBlock::iterator I,
                                   DebugLoc DL,
                                   const TargetInstrDesc &TID) {
  MachineInstr *MI = BB.getParent()->CreateMachineInstr(TID, DL);
  BB.insert(I, MI);
  return MachineInstrBuilder(MI);
}

/// BuildMI - This version of the builder inserts the newly-built
/// instruction at the end of the given MachineBasicBlock, and does NOT take a
/// destination register.
///
inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
                                   DebugLoc DL,
                                   const TargetInstrDesc &TID) {
  return BuildMI(*BB, BB->end(), DL, TID);
}

/// BuildMI - This version of the builder inserts the newly-built
/// instruction at the end of the given MachineBasicBlock, and sets up the first
/// operand as a destination virtual register. 
///
inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
                                   DebugLoc DL,
                                   const TargetInstrDesc &TID,
                                   unsigned DestReg) {
  return BuildMI(*BB, BB->end(), DL, TID, DestReg);
}

inline unsigned getDefRegState(bool B) {
  return B ? RegState::Define : 0;
}
inline unsigned getImplRegState(bool B) {
  return B ? RegState::Implicit : 0;
}
inline unsigned getKillRegState(bool B) {
  return B ? RegState::Kill : 0;
}
inline unsigned getDeadRegState(bool B) {
  return B ? RegState::Dead : 0;
}

} // End llvm namespace

#endif