C++ ARMFunctionInfo::isGPRCalleeSavedArea2Frame方法代码示例

void
Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
                                        int SPAdj, RegScavenger *RS) const {
  unsigned VReg = 0;
  unsigned i = 0;
  MachineInstr &MI = *II;
  MachineBasicBlock &MBB = *MI.getParent();
  MachineFunction &MF = *MBB.getParent();
  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
  DebugLoc dl = MI.getDebugLoc();

  while (!MI.getOperand(i).isFI()) {
    ++i;
    assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
  }

  unsigned FrameReg = ARM::SP;
  int FrameIndex = MI.getOperand(i).getIndex();
  int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
               MF.getFrameInfo()->getStackSize() + SPAdj;

  if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
    Offset -= AFI->getGPRCalleeSavedArea1Offset();
  else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
    Offset -= AFI->getGPRCalleeSavedArea2Offset();
  else if (MF.getFrameInfo()->hasVarSizedObjects()) {
    assert(SPAdj == 0 && MF.getTarget().getFrameInfo()->hasFP(MF) &&
           "Unexpected");
    // There are alloca()'s in this function, must reference off the frame
    // pointer or base pointer instead.
    if (!hasBasePointer(MF)) {
      FrameReg = getFrameRegister(MF);
      Offset -= AFI->getFramePtrSpillOffset();
    } else
      FrameReg = BasePtr;
  }

  // Special handling of dbg_value instructions.
  if (MI.isDebugValue()) {
    MI.getOperand(i).  ChangeToRegister(FrameReg, false /*isDef*/);
    MI.getOperand(i+1).ChangeToImmediate(Offset);
    return;
  }

  // Modify MI as necessary to handle as much of 'Offset' as possible
  assert(AFI->isThumbFunction() &&
         "This eliminateFrameIndex only supports Thumb1!");
  if (rewriteFrameIndex(MI, i, FrameReg, Offset, TII))
    return;

  // If we get here, the immediate doesn't fit into the instruction.  We folded
  // as much as possible above, handle the rest, providing a register that is
  // SP+LargeImm.
  assert(Offset && "This code isn't needed if offset already handled!");

  unsigned Opcode = MI.getOpcode();
  const TargetInstrDesc &Desc = MI.getDesc();

  // Remove predicate first.
  int PIdx = MI.findFirstPredOperandIdx();
  if (PIdx != -1)
    removeOperands(MI, PIdx);

  if (Desc.mayLoad()) {
    // Use the destination register to materialize sp + offset.
    unsigned TmpReg = MI.getOperand(0).getReg();
    bool UseRR = false;
    if (Opcode == ARM::tRestore) {
      if (FrameReg == ARM::SP)
        emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,
                                 Offset, false, TII, *this, dl);
      else {
        emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset);
        UseRR = true;
      }
    } else {
      emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII,
                                *this, dl);
    }

    MI.setDesc(TII.get(ARM::tLDR));
    MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
    if (UseRR)
      // Use [reg, reg] addrmode.
      MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
    else  // tLDR has an extra register operand.
      MI.addOperand(MachineOperand::CreateReg(0, false));
  } else if (Desc.mayStore()) {
      VReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
      bool UseRR = false;

      if (Opcode == ARM::tSpill) {
        if (FrameReg == ARM::SP)
          emitThumbRegPlusImmInReg(MBB, II, VReg, FrameReg,
                                   Offset, false, TII, *this, dl);
        else {
          emitLoadConstPool(MBB, II, dl, VReg, 0, Offset);
          UseRR = true;
        }
      } else
//.........这里部分代码省略.........

void
Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
                                        int SPAdj, unsigned FIOperandNum,
                                        RegScavenger *RS) const {
  unsigned VReg = 0;
  MachineInstr &MI = *II;
  MachineBasicBlock &MBB = *MI.getParent();
  MachineFunction &MF = *MBB.getParent();
  const ARMBaseInstrInfo &TII =
    *static_cast<const ARMBaseInstrInfo*>(MF.getTarget().getInstrInfo());
  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
  DebugLoc dl = MI.getDebugLoc();
  MachineInstrBuilder MIB(*MBB.getParent(), &MI);

  unsigned FrameReg = ARM::SP;
  int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
  int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
               MF.getFrameInfo()->getStackSize() + SPAdj;

  if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
    Offset -= AFI->getGPRCalleeSavedArea1Offset();
  else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
    Offset -= AFI->getGPRCalleeSavedArea2Offset();
  else if (MF.getFrameInfo()->hasVarSizedObjects()) {
    assert(SPAdj == 0 && MF.getTarget().getFrameLowering()->hasFP(MF) &&
           "Unexpected");
    // There are alloca()'s in this function, must reference off the frame
    // pointer or base pointer instead.
    if (!hasBasePointer(MF)) {
      FrameReg = getFrameRegister(MF);
      Offset -= AFI->getFramePtrSpillOffset();
    } else
      FrameReg = BasePtr;
  }

  // PEI::scavengeFrameVirtualRegs() cannot accurately track SPAdj because the
  // call frame setup/destroy instructions have already been eliminated.  That
  // means the stack pointer cannot be used to access the emergency spill slot
  // when !hasReservedCallFrame().
#ifndef NDEBUG
  if (RS && FrameReg == ARM::SP && RS->isScavengingFrameIndex(FrameIndex)){
    assert(MF.getTarget().getFrameLowering()->hasReservedCallFrame(MF) &&
           "Cannot use SP to access the emergency spill slot in "
           "functions without a reserved call frame");
    assert(!MF.getFrameInfo()->hasVarSizedObjects() &&
           "Cannot use SP to access the emergency spill slot in "
           "functions with variable sized frame objects");
  }
#endif // NDEBUG

  // Special handling of dbg_value instructions.
  if (MI.isDebugValue()) {
    MI.getOperand(FIOperandNum).  ChangeToRegister(FrameReg, false /*isDef*/);
    MI.getOperand(FIOperandNum+1).ChangeToImmediate(Offset);
    return;
  }

  // Modify MI as necessary to handle as much of 'Offset' as possible
  assert(AFI->isThumbFunction() &&
         "This eliminateFrameIndex only supports Thumb1!");
  if (rewriteFrameIndex(MI, FIOperandNum, FrameReg, Offset, TII))
    return;

  // If we get here, the immediate doesn't fit into the instruction.  We folded
  // as much as possible above, handle the rest, providing a register that is
  // SP+LargeImm.
  assert(Offset && "This code isn't needed if offset already handled!");

  unsigned Opcode = MI.getOpcode();

  // Remove predicate first.
  int PIdx = MI.findFirstPredOperandIdx();
  if (PIdx != -1)
    removeOperands(MI, PIdx);

  if (MI.mayLoad()) {
    // Use the destination register to materialize sp + offset.
    unsigned TmpReg = MI.getOperand(0).getReg();
    bool UseRR = false;
    if (Opcode == ARM::tLDRspi) {
      if (FrameReg == ARM::SP)
        emitThumbRegPlusImmInReg(MBB, II, dl, TmpReg, FrameReg,
                                 Offset, false, TII, *this);
      else {
        emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset);
        UseRR = true;
      }
    } else {
      emitThumbRegPlusImmediate(MBB, II, dl, TmpReg, FrameReg, Offset, TII,
                                *this);
    }

    MI.setDesc(TII.get(UseRR ? ARM::tLDRr : ARM::tLDRi));
    MI.getOperand(FIOperandNum).ChangeToRegister(TmpReg, false, false, true);
    if (UseRR)
      // Use [reg, reg] addrmode. Replace the immediate operand w/ the frame
      // register. The offset is already handled in the vreg value.
      MI.getOperand(FIOperandNum+1).ChangeToRegister(FrameReg, false, false,
                                                     false);
  } else if (MI.mayStore()) {
//.........这里部分代码省略.........

unsigned
Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
                                        int SPAdj, int *Value,
                                        RegScavenger *RS) const{
  unsigned VReg = 0;
  unsigned i = 0;
  MachineInstr &MI = *II;
  MachineBasicBlock &MBB = *MI.getParent();
  MachineFunction &MF = *MBB.getParent();
  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
  DebugLoc dl = MI.getDebugLoc();

  while (!MI.getOperand(i).isFI()) {
    ++i;
    assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
  }

  unsigned FrameReg = ARM::SP;
  int FrameIndex = MI.getOperand(i).getIndex();
  int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
               MF.getFrameInfo()->getStackSize() + SPAdj;

  if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
    Offset -= AFI->getGPRCalleeSavedArea1Offset();
  else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
    Offset -= AFI->getGPRCalleeSavedArea2Offset();
  else if (hasFP(MF)) {
    assert(SPAdj == 0 && "Unexpected");
    // There is alloca()'s in this function, must reference off the frame
    // pointer instead.
    FrameReg = getFrameRegister(MF);
    Offset -= AFI->getFramePtrSpillOffset();
  }

  unsigned Opcode = MI.getOpcode();
  const TargetInstrDesc &Desc = MI.getDesc();
  unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);

  if (Opcode == ARM::tADDrSPi) {
    Offset += MI.getOperand(i+1).getImm();

    // Can't use tADDrSPi if it's based off the frame pointer.
    unsigned NumBits = 0;
    unsigned Scale = 1;
    if (FrameReg != ARM::SP) {
      Opcode = ARM::tADDi3;
      MI.setDesc(TII.get(Opcode));
      NumBits = 3;
    } else {
      NumBits = 8;
      Scale = 4;
      assert((Offset & 3) == 0 &&
             "Thumb add/sub sp, #imm immediate must be multiple of 4!");
    }

    if (Offset == 0) {
      // Turn it into a move.
      MI.setDesc(TII.get(ARM::tMOVgpr2tgpr));
      MI.getOperand(i).ChangeToRegister(FrameReg, false);
      MI.RemoveOperand(i+1);
      return 0;
    }

    // Common case: small offset, fits into instruction.
    unsigned Mask = (1 << NumBits) - 1;
    if (((Offset / Scale) & ~Mask) == 0) {
      // Replace the FrameIndex with sp / fp
      if (Opcode == ARM::tADDi3) {
        removeOperands(MI, i);
        MachineInstrBuilder MIB(&MI);
        AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg)
                       .addImm(Offset / Scale));
      } else {
        MI.getOperand(i).ChangeToRegister(FrameReg, false);
        MI.getOperand(i+1).ChangeToImmediate(Offset / Scale);
      }
      return 0;
    }

    unsigned DestReg = MI.getOperand(0).getReg();
    unsigned Bytes = (Offset > 0) ? Offset : -Offset;
    unsigned NumMIs = calcNumMI(Opcode, 0, Bytes, NumBits, Scale);
    // MI would expand into a large number of instructions. Don't try to
    // simplify the immediate.
    if (NumMIs > 2) {
      emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII,
                                *this, dl);
      MBB.erase(II);
      return 0;
    }

    if (Offset > 0) {
      // Translate r0 = add sp, imm to
      // r0 = add sp, 255*4
      // r0 = add r0, (imm - 255*4)
      if (Opcode == ARM::tADDi3) {
        removeOperands(MI, i);
        MachineInstrBuilder MIB(&MI);
        AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg).addImm(Mask));
      } else {
//.........这里部分代码省略.........