lib/CodeGen/MachineInstr.cpp

//===-- MachineInstr.cpp --------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Methods common to all machine instructions.
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/MRegisterInfo.h"
#include "llvm/Support/LeakDetector.h"
#include "llvm/Support/Streams.h"
#include <ostream>
using namespace llvm;

/// MachineInstr ctor - This constructor creates a dummy MachineInstr with
/// TID NULL and no operands.
MachineInstr::MachineInstr()
  : TID(0), NumImplicitOps(0), parent(0) {
  // Make sure that we get added to a machine basicblock
  LeakDetector::addGarbageObject(this);
}

void MachineInstr::addImplicitDefUseOperands() {
  if (TID->ImplicitDefs)
    for (const unsigned *ImpDefs = TID->ImplicitDefs; *ImpDefs; ++ImpDefs)
      addOperand(MachineOperand::CreateReg(*ImpDefs, true, true));
  if (TID->ImplicitUses)
    for (const unsigned *ImpUses = TID->ImplicitUses; *ImpUses; ++ImpUses)
      addOperand(MachineOperand::CreateReg(*ImpUses, false, true));
}

/// MachineInstr ctor - This constructor create a MachineInstr and add the
/// implicit operands. It reserves space for number of operands specified by
/// TargetInstrDescriptor or the numOperands if it is not zero. (for
/// instructions with variable number of operands).
MachineInstr::MachineInstr(const TargetInstrDescriptor &tid, bool NoImp)
  : TID(&tid), NumImplicitOps(0), parent(0) {
  if (!NoImp && TID->ImplicitDefs)
    for (const unsigned *ImpDefs = TID->ImplicitDefs; *ImpDefs; ++ImpDefs)
      NumImplicitOps++;
  if (!NoImp && TID->ImplicitUses)
    for (const unsigned *ImpUses = TID->ImplicitUses; *ImpUses; ++ImpUses)
      NumImplicitOps++;
  Operands.reserve(NumImplicitOps + TID->numOperands);
  if (!NoImp)
    addImplicitDefUseOperands();
  // Make sure that we get added to a machine basicblock
  LeakDetector::addGarbageObject(this);
}

/// MachineInstr ctor - Work exactly the same as the ctor above, except that the
/// MachineInstr is created and added to the end of the specified basic block.
///
MachineInstr::MachineInstr(MachineBasicBlock *MBB,
                           const TargetInstrDescriptor &tid)
  : TID(&tid), NumImplicitOps(0), parent(0) {
  assert(MBB && "Cannot use inserting ctor with null basic block!");
  if (TID->ImplicitDefs)
    for (const unsigned *ImpDefs = TID->ImplicitDefs; *ImpDefs; ++ImpDefs)
      NumImplicitOps++;
  if (TID->ImplicitUses)
    for (const unsigned *ImpUses = TID->ImplicitUses; *ImpUses; ++ImpUses)
      NumImplicitOps++;
  Operands.reserve(NumImplicitOps + TID->numOperands);
  addImplicitDefUseOperands();
  // Make sure that we get added to a machine basicblock
  LeakDetector::addGarbageObject(this);
  MBB->push_back(this);  // Add instruction to end of basic block!
}

/// MachineInstr ctor - Copies MachineInstr arg exactly
///
MachineInstr::MachineInstr(const MachineInstr &MI) {
  TID = MI.getInstrDescriptor();
  NumImplicitOps = MI.NumImplicitOps;
  Operands.reserve(MI.getNumOperands());

  // Add operands
  for (unsigned i = 0; i != MI.getNumOperands(); ++i) {
    Operands.push_back(MI.getOperand(i));
    Operands.back().ParentMI = this;
  }

  // Set parent, next, and prev to null
  parent = 0;
  prev = 0;
  next = 0;
}


MachineInstr::~MachineInstr() {
  LeakDetector::removeGarbageObject(this);
#ifndef NDEBUG
  for (unsigned i = 0, e = Operands.size(); i != e; ++i)
    assert(Operands[i].ParentMI == this && "ParentMI mismatch!");
#endif
}

/// getOpcode - Returns the opcode of this MachineInstr.
///
int MachineInstr::getOpcode() const {
  return TID->Opcode;
}

/// removeFromParent - This method unlinks 'this' from the containing basic
/// block, and returns it, but does not delete it.
MachineInstr *MachineInstr::removeFromParent() {
  assert(getParent() && "Not embedded in a basic block!");
  getParent()->remove(this);
  return this;
}


/// OperandComplete - Return true if it's illegal to add a new operand
///
bool MachineInstr::OperandsComplete() const {
  unsigned short NumOperands = TID->numOperands;
  if ((TID->Flags & M_VARIABLE_OPS) == 0 &&
      getNumOperands()-NumImplicitOps >= NumOperands)
    return true;  // Broken: we have all the operands of this instruction!
  return false;
}

/// getNumExplicitOperands - Returns the number of non-implicit operands.
///
unsigned MachineInstr::getNumExplicitOperands() const {
  unsigned NumOperands = TID->numOperands;
  if ((TID->Flags & M_VARIABLE_OPS) == 0)
    return NumOperands;

  for (unsigned e = getNumOperands(); NumOperands != e; ++NumOperands) {
    const MachineOperand &MO = getOperand(NumOperands);
    if (!MO.isRegister() || !MO.isImplicit())
      NumOperands++;
  }
  return NumOperands;
}

/// isIdenticalTo - Return true if this operand is identical to the specified
/// operand.
bool MachineOperand::isIdenticalTo(const MachineOperand &Other) const {
  if (getType() != Other.getType()) return false;
  
  switch (getType()) {
  default: assert(0 && "Unrecognized operand type");
  case MachineOperand::MO_Register:
    return getReg() == Other.getReg() && isDef() == Other.isDef() &&
           getSubReg() == Other.getSubReg();
  case MachineOperand::MO_Immediate:
    return getImm() == Other.getImm();
  case MachineOperand::MO_MachineBasicBlock:
    return getMBB() == Other.getMBB();
  case MachineOperand::MO_FrameIndex:
    return getFrameIndex() == Other.getFrameIndex();
  case MachineOperand::MO_ConstantPoolIndex:
    return getConstantPoolIndex() == Other.getConstantPoolIndex() &&
           getOffset() == Other.getOffset();
  case MachineOperand::MO_JumpTableIndex:
    return getJumpTableIndex() == Other.getJumpTableIndex();
  case MachineOperand::MO_GlobalAddress:
    return getGlobal() == Other.getGlobal() && getOffset() == Other.getOffset();
  case MachineOperand::MO_ExternalSymbol:
    return !strcmp(getSymbolName(), Other.getSymbolName()) &&
           getOffset() == Other.getOffset();
  }
}

/// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of
/// the specific register or -1 if it is not found. It further tightening
/// the search criteria to a use that kills the register if isKill is true.
int MachineInstr::findRegisterUseOperandIdx(unsigned Reg, bool isKill) const {
  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
    const MachineOperand &MO = getOperand(i);
    if (MO.isRegister() && MO.isUse() && MO.getReg() == Reg)
      if (!isKill || MO.isKill())
        return i;
  }
  return -1;
}
  
/// findRegisterDefOperand() - Returns the MachineOperand that is a def of
/// the specific register or NULL if it is not found.
MachineOperand *MachineInstr::findRegisterDefOperand(unsigned Reg) {
  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
    MachineOperand &MO = getOperand(i);
    if (MO.isRegister() && MO.isDef() && MO.getReg() == Reg)
      return &MO;
  }
  return NULL;
}

/// findFirstPredOperandIdx() - Find the index of the first operand in the
/// operand list that is used to represent the predicate. It returns -1 if
/// none is found.
int MachineInstr::findFirstPredOperandIdx() const {
  const TargetInstrDescriptor *TID = getInstrDescriptor();
  if (TID->Flags & M_PREDICABLE) {
    for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
      if ((TID->OpInfo[i].Flags & M_PREDICATE_OPERAND))
        return i;
  }

  return -1;
}
  
/// isRegReDefinedByTwoAddr - Returns true if the Reg re-definition is due
/// to two addr elimination.
bool MachineInstr::isRegReDefinedByTwoAddr(unsigned Reg) const {
  const TargetInstrDescriptor *TID = getInstrDescriptor();
  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
    const MachineOperand &MO1 = getOperand(i);
    if (MO1.isRegister() && MO1.isDef() && MO1.getReg() == Reg) {
      for (unsigned j = i+1; j < e; ++j) {
        const MachineOperand &MO2 = getOperand(j);
        if (MO2.isRegister() && MO2.isUse() && MO2.getReg() == Reg &&
            TID->getOperandConstraint(j, TOI::TIED_TO) == (int)i)
          return true;
      }
    }
  }
  return false;
}

/// copyKillDeadInfo - Copies kill / dead operand properties from MI.
///
void MachineInstr::copyKillDeadInfo(const MachineInstr *MI) {
  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
    const MachineOperand &MO = MI->getOperand(i);
    if (!MO.isRegister() || (!MO.isKill() && !MO.isDead()))
      continue;
    for (unsigned j = 0, ee = getNumOperands(); j != ee; ++j) {
      MachineOperand &MOp = getOperand(j);
      if (!MOp.isIdenticalTo(MO))
        continue;
      if (MO.isKill())
        MOp.setIsKill();
      else
        MOp.setIsDead();
      break;
    }
  }
}

/// copyPredicates - Copies predicate operand(s) from MI.
void MachineInstr::copyPredicates(const MachineInstr *MI) {
  const TargetInstrDescriptor *TID = MI->getInstrDescriptor();
  if (TID->Flags & M_PREDICABLE) {
    for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
      if ((TID->OpInfo[i].Flags & M_PREDICATE_OPERAND)) {
        // Predicated operands must be last operands.
        addOperand(MI->getOperand(i));
      }
    }
  }
}

void MachineInstr::dump() const {
  cerr << "  " << *this;
}

/// print - Print the specified machine operand.
///
static void print(const MachineOperand &MO, std::ostream &OS,
                  const TargetMachine *TM) {
  switch (MO.getType()) {
  case MachineOperand::MO_Register:
    if (MO.getReg() == 0 || MRegisterInfo::isVirtualRegister(MO.getReg()))
      OS << "%reg" << MO.getReg();
    else {
      // If the instruction is embedded into a basic block, we can find the
      // target
      // info for the instruction.
      if (TM == 0)
        if (const MachineInstr *MI = MO.getParent())
          if (const MachineBasicBlock *MBB = MI->getParent())
            if (const MachineFunction *MF = MBB->getParent())
              TM = &MF->getTarget();
      
      if (TM)
        OS << "%" << TM->getRegisterInfo()->get(MO.getReg()).Name;
      else
        OS << "%mreg" << MO.getReg();
    }
      
    if (MO.isDef() || MO.isKill() || MO.isDead() || MO.isImplicit()) {
      OS << "<";
      bool NeedComma = false;
      if (MO.isImplicit()) {
        OS << (MO.isDef() ? "imp-def" : "imp-use");
        NeedComma = true;
      } else if (MO.isDef()) {
        OS << "def";
        NeedComma = true;
      }
      if (MO.isKill() || MO.isDead()) {
        if (NeedComma)    OS << ",";
        if (MO.isKill()) OS << "kill";
        if (MO.isDead()) OS << "dead";
      }
      OS << ">";
    }
    break;
  case MachineOperand::MO_Immediate:
    OS << MO.getImm();
    break;
  case MachineOperand::MO_MachineBasicBlock:
    OS << "mbb<"
       << ((Value*)MO.getMachineBasicBlock()->getBasicBlock())->getName()
       << "," << (void*)MO.getMachineBasicBlock() << ">";
    break;
  case MachineOperand::MO_FrameIndex:
    OS << "<fi#" << MO.getFrameIndex() << ">";
    break;
  case MachineOperand::MO_ConstantPoolIndex:
    OS << "<cp#" << MO.getConstantPoolIndex();
    if (MO.getOffset()) OS << "+" << MO.getOffset();
    OS << ">";
    break;
  case MachineOperand::MO_JumpTableIndex:
    OS << "<jt#" << MO.getJumpTableIndex() << ">";
    break;
  case MachineOperand::MO_GlobalAddress:
    OS << "<ga:" << ((Value*)MO.getGlobal())->getName();
    if (MO.getOffset()) OS << "+" << MO.getOffset();
    OS << ">";
    break;
  case MachineOperand::MO_ExternalSymbol:
    OS << "<es:" << MO.getSymbolName();
    if (MO.getOffset()) OS << "+" << MO.getOffset();
    OS << ">";
    break;
  default:
    assert(0 && "Unrecognized operand type");
  }
}

void MachineInstr::print(std::ostream &OS, const TargetMachine *TM) const {
  // Specialize printing if op#0 is definition
  unsigned StartOp = 0;
  if (getNumOperands() && getOperand(0).isRegister() && getOperand(0).isDef()) {
    ::print(getOperand(0), OS, TM);
    OS << " = ";
    ++StartOp;   // Don't print this operand again!
  }

  OS << getInstrDescriptor()->Name;

  for (unsigned i = StartOp, e = getNumOperands(); i != e; ++i) {
    if (i != StartOp)
      OS << ",";
    OS << " ";
    ::print(getOperand(i), OS, TM);
  }

  OS << "\n";
}

void MachineOperand::print(std::ostream &OS) const {
  ::print(*this, OS, 0);
}