Ejemplo n.º 1
0
void XCoreFrameInfo::emitEpilogue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
  MachineFrameInfo *MFI            = MF.getFrameInfo();
  MachineBasicBlock::iterator MBBI = prior(MBB.end());
  const XCoreInstrInfo &TII =
    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
  DebugLoc dl = MBBI->getDebugLoc();

  bool FP = hasFP(MF);
  if (FP) {
    // Restore the stack pointer.
    unsigned FramePtr = XCore::R10;
    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r))
      .addReg(FramePtr);
  }

  // Work out frame sizes.
  int FrameSize = MFI->getStackSize();

  assert(FrameSize%4 == 0 && "Misaligned frame size");

  FrameSize/=4;

  bool isU6 = isImmU6(FrameSize);

  if (!isU6 && !isImmU16(FrameSize)) {
    // FIXME could emit multiple instructions.
    report_fatal_error("emitEpilogue Frame size too big: " + Twine(FrameSize));
  }

  if (FrameSize) {
    XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();

    if (FP) {
      // Restore R10
      int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
      FPSpillOffset += FrameSize*4;
      loadFromStack(MBB, MBBI, XCore::R10, FPSpillOffset, dl, TII);
    }
    bool restoreLR = XFI->getUsesLR();
    if (restoreLR && MFI->getObjectOffset(XFI->getLRSpillSlot()) != 0) {
      int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
      LRSpillOffset += FrameSize*4;
      loadFromStack(MBB, MBBI, XCore::LR, LRSpillOffset, dl, TII);
      restoreLR = false;
    }
    if (restoreLR) {
      // Fold prologue into return instruction
      assert(MBBI->getOpcode() == XCore::RETSP_u6
        || MBBI->getOpcode() == XCore::RETSP_lu6);
      int Opcode = (isU6) ? XCore::RETSP_u6 : XCore::RETSP_lu6;
      BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);
      MBB.erase(MBBI);
    } else {
      int Opcode = (isU6) ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs;
      BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(FrameSize);
    }
  }
}
void NyuziFrameLowering::emitPrologue(MachineFunction &MF,
                                      MachineBasicBlock &MBB) const {
  assert(&MF.front() == &MBB);
  MachineFrameInfo *MFI = MF.getFrameInfo();
  const NyuziInstrInfo &TII =
      *static_cast<const NyuziInstrInfo *>(MF.getSubtarget().getInstrInfo());
  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

  // Compute stack size to allocate, keeping SP 64 byte aligned so we
  // can do block vector load/stores
  int StackSize = RoundUpToAlignment(MFI->getStackSize(), getStackAlignment());

  // Bail if there is no stack allocation
  if (StackSize == 0 && !MFI->adjustsStack())
    return;

  TII.adjustStackPointer(MBB, MBBI, -StackSize);

  // Emit DW_CFA_def_cfa
  unsigned CFIIndex = MMI.addFrameInst(
      MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize));
  BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
      .addCFIIndex(CFIIndex);

  // Find the instruction past the last instruction that saves a callee-saved
  // register to the stack.  We need to set up FP after its old value has been
  // saved.
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
  if (CSI.size()) {
    for (unsigned i = 0; i < CSI.size(); ++i)
      ++MBBI;

    // Iterate over list of callee-saved registers and emit .cfi_offset
    // directives (debug information)
    for (const auto &I : CSI) {
      int64_t Offset = MFI->getObjectOffset(I.getFrameIdx());
      unsigned Reg = I.getReg();
      unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
          nullptr, MRI->getDwarfRegNum(Reg, 1), Offset));
      BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex);
    }
  }

  // fp = sp
  if (hasFP(MF)) {
    BuildMI(MBB, MBBI, DL, TII.get(Nyuzi::MOVESS))
        .addReg(Nyuzi::FP_REG)
        .addReg(Nyuzi::SP_REG);

    // emit ".cfi_def_cfa_register $fp" (debug information)
    unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
        nullptr, MRI->getDwarfRegNum(Nyuzi::FP_REG, true)));
    BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex);
  }
}
Ejemplo n.º 3
0
unsigned
SPURegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
                                     FrameIndexValue *Value,
                                     RegScavenger *RS) const
{
    unsigned i = 0;
    MachineInstr &MI = *II;
    MachineBasicBlock &MBB = *MI.getParent();
    MachineFunction &MF = *MBB.getParent();
    MachineFrameInfo *MFI = MF.getFrameInfo();
    DebugLoc dl = II->getDebugLoc();

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

    MachineOperand &SPOp = MI.getOperand(i);
    int FrameIndex = SPOp.getIndex();

    // Now add the frame object offset to the offset from r1.
    int Offset = MFI->getObjectOffset(FrameIndex);

    // Most instructions, except for generated FrameIndex additions using AIr32
    // and ILAr32, have the immediate in operand 1. AIr32 and ILAr32 have the
    // immediate in operand 2.
    unsigned OpNo = 1;
    if (MI.getOpcode() == SPU::AIr32 || MI.getOpcode() == SPU::ILAr32)
        OpNo = 2;

    MachineOperand &MO = MI.getOperand(OpNo);

    // Offset is biased by $lr's slot at the bottom.
    Offset += MO.getImm() + MFI->getStackSize() + SPUFrameInfo::minStackSize();
    assert((Offset & 0xf) == 0
           && "16-byte alignment violated in eliminateFrameIndex");

    // Replace the FrameIndex with base register with $sp (aka $r1)
    SPOp.ChangeToRegister(SPU::R1, false);

    // if 'Offset' doesn't fit to the D-form instruction's
    // immediate, convert the instruction to X-form
    // if the instruction is not an AI (which takes a s10 immediate), assume
    // it is a load/store that can take a s14 immediate
    if ((MI.getOpcode() == SPU::AIr32 && !isInt<10>(Offset))
            || !isInt<14>(Offset)) {
        int newOpcode = convertDFormToXForm(MI.getOpcode());
        unsigned tmpReg = findScratchRegister(II, RS, &SPU::R32CRegClass, SPAdj);
        BuildMI(MBB, II, dl, TII.get(SPU::ILr32), tmpReg )
        .addImm(Offset);
        BuildMI(MBB, II, dl, TII.get(newOpcode), MI.getOperand(0).getReg())
        .addReg(tmpReg, RegState::Kill)
        .addReg(SPU::R1);
        // remove the replaced D-form instruction
        MBB.erase(II);
    } else {
        MO.ChangeToImmediate(Offset);
    }
    return 0;
}
Ejemplo n.º 4
0
void
Dcpu16RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
                                       int SPAdj, RegScavenger *RS) const {
  assert(SPAdj == 0 && "Unexpected");

  unsigned i = 0;
  MachineInstr &MI = *II;
  DebugLoc dl = MI.getDebugLoc();
  while (!MI.getOperand(i).isFI()) {
    ++i;
    assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
  }

  int FrameIndex = MI.getOperand(i).getIndex();

  // Addressable stack objects are accessed using neg. offsets from %fp
  MachineFunction &MF = *MI.getParent()->getParent();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  int Offset = MFI->getStackSize() +
               MFI->getObjectOffset(FrameIndex) +
               MI.getOperand(i+1).getImm();

  // Replace frame index with a frame pointer reference.
  // If the offset is small enough to fit in the immediate field, directly
  // encode it.
  MI.getOperand(i).ChangeToRegister(DCPU16::SP, false);
  MI.getOperand(i+1).ChangeToImmediate(Offset);
}
Ejemplo n.º 5
0
void AArch64FrameLowering::emitCalleeSavedFrameMoves(
    MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI) const {
  MachineFunction &MF = *MBB.getParent();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
  DebugLoc DL = MBB.findDebugLoc(MBBI);

  // Add callee saved registers to move list.
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
  if (CSI.empty())
    return;

  for (const auto &Info : CSI) {
    unsigned Reg = Info.getReg();
    int64_t Offset =
        MFI->getObjectOffset(Info.getFrameIdx()) - getOffsetOfLocalArea();
    unsigned DwarfReg = MRI->getDwarfRegNum(Reg, true);
    unsigned CFIIndex = MMI.addFrameInst(
        MCCFIInstruction::createOffset(nullptr, DwarfReg, Offset));
    BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex)
        .setMIFlags(MachineInstr::FrameSetup);
  }
}
Ejemplo n.º 6
0
int64_t
AArch64FrameLowering::resolveFrameIndexReference(MachineFunction &MF,
                                                 int FrameIndex,
                                                 unsigned &FrameReg,
                                                 int SPAdj,
                                                 bool IsCalleeSaveOp) const {
  AArch64MachineFunctionInfo *FuncInfo =
    MF.getInfo<AArch64MachineFunctionInfo>();
  MachineFrameInfo *MFI = MF.getFrameInfo();

  int64_t TopOfFrameOffset = MFI->getObjectOffset(FrameIndex);

  assert(!(IsCalleeSaveOp && FuncInfo->getInitialStackAdjust() == 0)
         && "callee-saved register in unexpected place");

  // If the frame for this function is particularly large, we adjust the stack
  // in two phases which means the callee-save related operations see a
  // different (intermediate) stack size.
  int64_t FrameRegPos;
  if (IsCalleeSaveOp) {
    FrameReg = AArch64::XSP;
    FrameRegPos = -static_cast<int64_t>(FuncInfo->getInitialStackAdjust());
  } else if (useFPForAddressing(MF)) {
    // Have to use the frame pointer since we have no idea where SP is.
    FrameReg = AArch64::X29;
    FrameRegPos = FuncInfo->getFramePointerOffset();
  } else {
    FrameReg = AArch64::XSP;
    FrameRegPos = -static_cast<int64_t>(MFI->getStackSize()) + SPAdj;
  }

  return TopOfFrameOffset - FrameRegPos;
}
Ejemplo n.º 7
0
void Mips16FrameLowering::emitPrologue(MachineFunction &MF,
                                       MachineBasicBlock &MBB) const {
  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
  MachineFrameInfo *MFI = MF.getFrameInfo();
  const Mips16InstrInfo &TII =
      *static_cast<const Mips16InstrInfo *>(STI.getInstrInfo());
  MachineBasicBlock::iterator MBBI = MBB.begin();

  // Debug location must be unknown since the first debug location is used
  // to determine the end of the prologue.
  DebugLoc dl;

  uint64_t StackSize = MFI->getStackSize();

  // No need to allocate space on the stack.
  if (StackSize == 0 && !MFI->adjustsStack()) return;

  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  MachineLocation DstML, SrcML;

  // Adjust stack.
  TII.makeFrame(Mips::SP, StackSize, MBB, MBBI);

  // emit ".cfi_def_cfa_offset StackSize"
  unsigned CFIIndex = MMI.addFrameInst(
      MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize));
  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
      .addCFIIndex(CFIIndex);

  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

  if (CSI.size()) {
    const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

    for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
         E = CSI.end(); I != E; ++I) {
      int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
      unsigned Reg = I->getReg();
      unsigned DReg = MRI->getDwarfRegNum(Reg, true);
      unsigned CFIIndex = MMI.addFrameInst(
          MCCFIInstruction::createOffset(nullptr, DReg, Offset));
      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex);
    }
  }
  if (hasFP(MF))
    BuildMI(MBB, MBBI, dl, TII.get(Mips::MoveR3216), Mips::S0)
      .addReg(Mips::SP).setMIFlag(MachineInstr::FrameSetup);

}
Ejemplo n.º 8
0
void Mips16FrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB = MF.front();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  const Mips16InstrInfo &TII =
    *static_cast<const Mips16InstrInfo*>(MF.getTarget().getInstrInfo());
  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
  uint64_t StackSize = MFI->getStackSize();

  // No need to allocate space on the stack.
  if (StackSize == 0 && !MFI->adjustsStack()) return;

  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  MachineLocation DstML, SrcML;

  // Adjust stack.
  TII.makeFrame(Mips::SP, StackSize, MBB, MBBI);

  // emit ".cfi_def_cfa_offset StackSize"
  MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
  BuildMI(MBB, MBBI, dl,
          TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
  MMI.addFrameInst(
      MCCFIInstruction::createDefCfaOffset(AdjustSPLabel, -StackSize));

  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

  if (CSI.size()) {
    MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);


    const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

    for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
         E = CSI.end(); I != E; ++I) {
      int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
      unsigned Reg = I->getReg();
      unsigned DReg = MRI->getDwarfRegNum(Reg, true);
      MMI.addFrameInst(MCCFIInstruction::createOffset(CSLabel, DReg, Offset));
    }
  }
  if (hasFP(MF))
    BuildMI(MBB, MBBI, dl, TII.get(Mips::MoveR3216), Mips::S0)
      .addReg(Mips::SP);

}
unsigned
SPURegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
                                     FrameIndexValue *Value,
                                     RegScavenger *RS) const
{
  unsigned i = 0;
  MachineInstr &MI = *II;
  MachineBasicBlock &MBB = *MI.getParent();
  MachineFunction &MF = *MBB.getParent();
  MachineFrameInfo *MFI = MF.getFrameInfo();

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

  MachineOperand &SPOp = MI.getOperand(i);
  int FrameIndex = SPOp.getIndex();

  // Now add the frame object offset to the offset from r1.
  int Offset = MFI->getObjectOffset(FrameIndex);

  // Most instructions, except for generated FrameIndex additions using AIr32
  // and ILAr32, have the immediate in operand 1. AIr32 and ILAr32 have the
  // immediate in operand 2.
  unsigned OpNo = 1;
  if (MI.getOpcode() == SPU::AIr32 || MI.getOpcode() == SPU::ILAr32)
    OpNo = 2;

  MachineOperand &MO = MI.getOperand(OpNo);

  // Offset is biased by $lr's slot at the bottom.
  Offset += MO.getImm() + MFI->getStackSize() + SPUFrameInfo::minStackSize();
  assert((Offset & 0xf) == 0
         && "16-byte alignment violated in eliminateFrameIndex");

  // Replace the FrameIndex with base register with $sp (aka $r1)
  SPOp.ChangeToRegister(SPU::R1, false);
  if (Offset > SPUFrameInfo::maxFrameOffset()
      || Offset < SPUFrameInfo::minFrameOffset()) {
    errs() << "Large stack adjustment ("
         << Offset
         << ") in SPURegisterInfo::eliminateFrameIndex.";
  } else {
    MO.ChangeToImmediate(Offset);
  }
  return 0;
}
void AArch64FrameLowering::emitCalleeSavedFrameMoves(
    MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
    unsigned FramePtr) const {
  MachineFunction &MF = *MBB.getParent();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
  DebugLoc DL = MBB.findDebugLoc(MBBI);

  // Add callee saved registers to move list.
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
  if (CSI.empty())
    return;

  const DataLayout &TD = MF.getDataLayout();
  bool HasFP = hasFP(MF);

  // Calculate amount of bytes used for return address storing.
  int stackGrowth = -TD.getPointerSize(0);

  // Calculate offsets.
  int64_t saveAreaOffset = (HasFP ? 2 : 1) * stackGrowth;
  unsigned TotalSkipped = 0;
  for (const auto &Info : CSI) {
    unsigned Reg = Info.getReg();
    int64_t Offset = MFI->getObjectOffset(Info.getFrameIdx()) -
                     getOffsetOfLocalArea() + saveAreaOffset;

    // Don't output a new CFI directive if we're re-saving the frame pointer or
    // link register. This happens when the PrologEpilogInserter has inserted an
    // extra "STP" of the frame pointer and link register -- the "emitPrologue"
    // method automatically generates the directives when frame pointers are
    // used. If we generate CFI directives for the extra "STP"s, the linker will
    // lose track of the correct values for the frame pointer and link register.
    if (HasFP && (FramePtr == Reg || Reg == AArch64::LR)) {
      TotalSkipped += stackGrowth;
      continue;
    }

    unsigned DwarfReg = MRI->getDwarfRegNum(Reg, true);
    unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
        nullptr, DwarfReg, Offset - TotalSkipped));
    BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex)
        .setMIFlags(MachineInstr::FrameSetup);
  }
}
Ejemplo n.º 11
0
int SystemZRegisterInfo::getFrameIndexOffset(MachineFunction &MF, int FI) const {
  const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  SystemZMachineFunctionInfo *SystemZMFI =
    MF.getInfo<SystemZMachineFunctionInfo>();
  int Offset = MFI->getObjectOffset(FI) + MFI->getOffsetAdjustment();
  uint64_t StackSize = MFI->getStackSize();

  // Fixed objects are really located in the "previous" frame.
  if (FI < 0)
    StackSize -= SystemZMFI->getCalleeSavedFrameSize();

  Offset += StackSize - TFI.getOffsetOfLocalArea();

  // Skip the register save area if we generated the stack frame.
  if (StackSize || MFI->hasCalls())
    Offset -= TFI.getOffsetOfLocalArea();

  return Offset;
}
Ejemplo n.º 12
0
SIMachineFunctionInfo::SpilledReg SIMachineFunctionInfo::getSpilledReg (
                                                       MachineFunction *MF,
                                                       unsigned FrameIndex,
                                                       unsigned SubIdx) {
  if (!EnableSpillSGPRToVGPR)
    return SpilledReg();

  const SISubtarget &ST = MF->getSubtarget<SISubtarget>();
  const SIRegisterInfo *TRI = ST.getRegisterInfo();

  MachineFrameInfo *FrameInfo = MF->getFrameInfo();
  MachineRegisterInfo &MRI = MF->getRegInfo();
  int64_t Offset = FrameInfo->getObjectOffset(FrameIndex);
  Offset += SubIdx * 4;

  unsigned LaneVGPRIdx = Offset / (64 * 4);
  unsigned Lane = (Offset / 4) % 64;

  struct SpilledReg Spill;
  Spill.Lane = Lane;

  if (!LaneVGPRs.count(LaneVGPRIdx)) {
    unsigned LaneVGPR = TRI->findUnusedRegister(MRI, &AMDGPU::VGPR_32RegClass);

    if (LaneVGPR == AMDGPU::NoRegister)
      // We have no VGPRs left for spilling SGPRs.
      return Spill;

    LaneVGPRs[LaneVGPRIdx] = LaneVGPR;

    // Add this register as live-in to all blocks to avoid machine verifer
    // complaining about use of an undefined physical register.
    for (MachineFunction::iterator BI = MF->begin(), BE = MF->end();
         BI != BE; ++BI) {
      BI->addLiveIn(LaneVGPR);
    }
  }

  Spill.VGPR = LaneVGPRs[LaneVGPRIdx];
  return Spill;
}
Ejemplo n.º 13
0
/// Compute which bytes of fixed and callee-save stack area are unused and keep
/// track of them in StackBytesFree.
static inline void
computeFreeStackSlots(MachineFrameInfo &MFI, bool StackGrowsDown,
                      unsigned MinCSFrameIndex, unsigned MaxCSFrameIndex,
                      int64_t FixedCSEnd, BitVector &StackBytesFree) {
  // Avoid undefined int64_t -> int conversion below in extreme case.
  if (FixedCSEnd > std::numeric_limits<int>::max())
    return;

  StackBytesFree.resize(FixedCSEnd, true);

  SmallVector<int, 16> AllocatedFrameSlots;
  // Add fixed objects.
  for (int i = MFI.getObjectIndexBegin(); i != 0; ++i)
    AllocatedFrameSlots.push_back(i);
  // Add callee-save objects.
  for (int i = MinCSFrameIndex; i <= (int)MaxCSFrameIndex; ++i)
    AllocatedFrameSlots.push_back(i);

  for (int i : AllocatedFrameSlots) {
    // These are converted from int64_t, but they should always fit in int
    // because of the FixedCSEnd check above.
    int ObjOffset = MFI.getObjectOffset(i);
    int ObjSize = MFI.getObjectSize(i);
    int ObjStart, ObjEnd;
    if (StackGrowsDown) {
      // ObjOffset is negative when StackGrowsDown is true.
      ObjStart = -ObjOffset - ObjSize;
      ObjEnd = -ObjOffset;
    } else {
      ObjStart = ObjOffset;
      ObjEnd = ObjOffset + ObjSize;
    }
    // Ignore fixed holes that are in the previous stack frame.
    if (ObjEnd > 0)
      StackBytesFree.reset(ObjStart, ObjEnd);
  }
}
Ejemplo n.º 14
0
void Nios2RegisterInfo::adjustNios2StackFrame(MachineFunction &MF) const
{
    MachineFrameInfo *MFI = MF.getFrameInfo();
    Nios2FunctionInfo *Nios2FI = MF.getInfo<Nios2FunctionInfo>();
    const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
    unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
    unsigned RegSize = 4;
    bool HasGP = Nios2FI->needGPSaveRestore();

    // Min and Max CSI FrameIndex.
    int MinCSFI = -1, MaxCSFI = -1; 

    // See the description at Nios2MachineFunction.h
    int TopCPUSavedRegOff = -1;

    // It happens that the default stack frame allocation order does not directly 
    // map to the convention used for nios2. So we must fix it. We move the callee 
    // save register slots after the local variables area, as described in the
    // stack frame above.
    unsigned CalleeSavedAreaSize = 0;
    if (!CSI.empty()) {
        MinCSFI = CSI[0].getFrameIdx();
        MaxCSFI = CSI[CSI.size()-1].getFrameIdx();
    }
    for (unsigned i = 0, e = CSI.size(); i != e; ++i)
        CalleeSavedAreaSize += MFI->getObjectAlignment(CSI[i].getFrameIdx());

  unsigned StackOffset = HasGP ? (Nios2FI->getGPStackOffset()+RegSize) : 16;

    // Adjust local variables. They should come on the stack right
    // after the arguments.
    int LastOffsetFI = -1;
    for (int i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
        if (i >= MinCSFI && i <= MaxCSFI)
            continue;
        if (MFI->isDeadObjectIndex(i))
            continue;
        unsigned Offset =
            StackOffset + MFI->getObjectOffset(i) - CalleeSavedAreaSize;
        if (LastOffsetFI == -1)
            LastOffsetFI = i;
        if (Offset > MFI->getObjectOffset(LastOffsetFI))
            LastOffsetFI = i;
        MFI->setObjectOffset(i, Offset);
    }

    // Adjust CPU Callee Saved Registers Area. Registers RA and FP must
    // be saved in this CPU Area. This whole Area must be aligned to the
    // default Stack Alignment requirements.

    if (LastOffsetFI >= 0)
        StackOffset = MFI->getObjectOffset(LastOffsetFI)+ 
                      MFI->getObjectSize(LastOffsetFI);
    StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign);

    int stackSize  = MF.getFrameInfo()->getStackSize();
    if (MFI->hasCalls()) {
        stackSize += RegSize;
    }

    if (hasFP(MF)) {
        stackSize += RegSize;
    }
    
    for (unsigned i = 0, e = CSI.size(); i != e ; ++i) {
        if (CSI[i].getRegClass() != Nios2::CPURegsRegisterClass)
            break;
        stackSize += RegSize;
    }

    if (MFI->hasCalls()) {
        MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true),
                             hasFP(MF) ? 4 : 0);
        Nios2FI->setRAStackOffset(hasFP(MF) ? 4 : 0);
        TopCPUSavedRegOff = hasFP(MF) ? 4 : 0;
        StackOffset += RegSize;
    }

    if (hasFP(MF)) {
        MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true), 0);
        Nios2FI->setFPStackOffset(0);
        TopCPUSavedRegOff = 0;
        StackOffset += RegSize;
    }

    for (unsigned i = 0, e = CSI.size(); i != e ; ++i) {
        if (CSI[i].getRegClass() != Nios2::CPURegsRegisterClass)
            break;
        MFI->setObjectOffset(CSI[i].getFrameIdx(), stackSize + (-(StackOffset + 4)));
        TopCPUSavedRegOff = stackSize + (-(StackOffset + 4));
        StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx());
    }

    // Update frame info
    MFI->setStackSize(stackSize);
}
Ejemplo n.º 15
0
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
/// abstract stack objects.
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
  const TargetFrameLowering &TFI = *Fn.getTarget().getFrameLowering();

  bool StackGrowsDown =
    TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;

  // Loop over all of the stack objects, assigning sequential addresses...
  MachineFrameInfo *MFI = Fn.getFrameInfo();

  // Start at the beginning of the local area.
  // The Offset is the distance from the stack top in the direction
  // of stack growth -- so it's always nonnegative.
  int LocalAreaOffset = TFI.getOffsetOfLocalArea();
  if (StackGrowsDown)
    LocalAreaOffset = -LocalAreaOffset;
  assert(LocalAreaOffset >= 0
         && "Local area offset should be in direction of stack growth");
  int64_t Offset = LocalAreaOffset;

  // If there are fixed sized objects that are preallocated in the local area,
  // non-fixed objects can't be allocated right at the start of local area.
  // We currently don't support filling in holes in between fixed sized
  // objects, so we adjust 'Offset' to point to the end of last fixed sized
  // preallocated object.
  for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
    int64_t FixedOff;
    if (StackGrowsDown) {
      // The maximum distance from the stack pointer is at lower address of
      // the object -- which is given by offset. For down growing stack
      // the offset is negative, so we negate the offset to get the distance.
      FixedOff = -MFI->getObjectOffset(i);
    } else {
      // The maximum distance from the start pointer is at the upper
      // address of the object.
      FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i);
    }
    if (FixedOff > Offset) Offset = FixedOff;
  }

  // First assign frame offsets to stack objects that are used to spill
  // callee saved registers.
  if (StackGrowsDown) {
    for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
      // If the stack grows down, we need to add the size to find the lowest
      // address of the object.
      Offset += MFI->getObjectSize(i);

      unsigned Align = MFI->getObjectAlignment(i);
      // Adjust to alignment boundary
      Offset = (Offset+Align-1)/Align*Align;

      MFI->setObjectOffset(i, -Offset);        // Set the computed offset
    }
  } else {
    int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex;
    for (int i = MaxCSFI; i >= MinCSFI ; --i) {
      unsigned Align = MFI->getObjectAlignment(i);
      // Adjust to alignment boundary
      Offset = (Offset+Align-1)/Align*Align;

      MFI->setObjectOffset(i, Offset);
      Offset += MFI->getObjectSize(i);
    }
  }

  unsigned MaxAlign = MFI->getMaxAlignment();

  // Make sure the special register scavenging spill slot is closest to the
  // frame pointer if a frame pointer is required.
  const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
  if (RS && TFI.hasFP(Fn) && RegInfo->useFPForScavengingIndex(Fn) &&
      !RegInfo->needsStackRealignment(Fn)) {
    int SFI = RS->getScavengingFrameIndex();
    if (SFI >= 0)
      AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
  }

  // FIXME: Once this is working, then enable flag will change to a target
  // check for whether the frame is large enough to want to use virtual
  // frame index registers. Functions which don't want/need this optimization
  // will continue to use the existing code path.
  if (MFI->getUseLocalStackAllocationBlock()) {
    unsigned Align = MFI->getLocalFrameMaxAlign();

    // Adjust to alignment boundary.
    Offset = (Offset + Align - 1) / Align * Align;

    DEBUG(dbgs() << "Local frame base offset: " << Offset << "\n");

    // Resolve offsets for objects in the local block.
    for (unsigned i = 0, e = MFI->getLocalFrameObjectCount(); i != e; ++i) {
      std::pair<int, int64_t> Entry = MFI->getLocalFrameObjectMap(i);
      int64_t FIOffset = (StackGrowsDown ? -Offset : Offset) + Entry.second;
      DEBUG(dbgs() << "alloc FI(" << Entry.first << ") at SP[" <<
            FIOffset << "]\n");
      MFI->setObjectOffset(Entry.first, FIOffset);
    }
    // Allocate the local block
    Offset += MFI->getLocalFrameSize();

    MaxAlign = std::max(Align, MaxAlign);
  }

  // Make sure that the stack protector comes before the local variables on the
  // stack.
  SmallSet<int, 16> LargeStackObjs;
  if (MFI->getStackProtectorIndex() >= 0) {
    AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown,
                      Offset, MaxAlign);

    // Assign large stack objects first.
    for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
      if (MFI->isObjectPreAllocated(i) &&
          MFI->getUseLocalStackAllocationBlock())
        continue;
      if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
        continue;
      if (RS && (int)i == RS->getScavengingFrameIndex())
        continue;
      if (MFI->isDeadObjectIndex(i))
        continue;
      if (MFI->getStackProtectorIndex() == (int)i)
        continue;
      if (!MFI->MayNeedStackProtector(i))
        continue;

      AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
      LargeStackObjs.insert(i);
    }
  }

  // Then assign frame offsets to stack objects that are not used to spill
  // callee saved registers.
  for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
    if (MFI->isObjectPreAllocated(i) &&
        MFI->getUseLocalStackAllocationBlock())
      continue;
    if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
      continue;
    if (RS && (int)i == RS->getScavengingFrameIndex())
      continue;
    if (MFI->isDeadObjectIndex(i))
      continue;
    if (MFI->getStackProtectorIndex() == (int)i)
      continue;
    if (LargeStackObjs.count(i))
      continue;

    AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
  }

  // Make sure the special register scavenging spill slot is closest to the
  // stack pointer.
  if (RS && (!TFI.hasFP(Fn) || RegInfo->needsStackRealignment(Fn) ||
             !RegInfo->useFPForScavengingIndex(Fn))) {
    int SFI = RS->getScavengingFrameIndex();
    if (SFI >= 0)
      AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
  }

  if (!TFI.targetHandlesStackFrameRounding()) {
    // If we have reserved argument space for call sites in the function
    // immediately on entry to the current function, count it as part of the
    // overall stack size.
    if (MFI->adjustsStack() && TFI.hasReservedCallFrame(Fn))
      Offset += MFI->getMaxCallFrameSize();

    // Round up the size to a multiple of the alignment.  If the function has
    // any calls or alloca's, align to the target's StackAlignment value to
    // ensure that the callee's frame or the alloca data is suitably aligned;
    // otherwise, for leaf functions, align to the TransientStackAlignment
    // value.
    unsigned StackAlign;
    if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
        (RegInfo->needsStackRealignment(Fn) && MFI->getObjectIndexEnd() != 0))
      StackAlign = TFI.getStackAlignment();
    else
      StackAlign = TFI.getTransientStackAlignment();

    // If the frame pointer is eliminated, all frame offsets will be relative to
    // SP not FP. Align to MaxAlign so this works.
    StackAlign = std::max(StackAlign, MaxAlign);
    unsigned AlignMask = StackAlign - 1;
    Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
  }

  // Update frame info to pretend that this is part of the stack...
  int64_t StackSize = Offset - LocalAreaOffset;
  MFI->setStackSize(StackSize);
  NumBytesStackSpace += StackSize;
}
Ejemplo n.º 16
0
void MipsFrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB   = MF.front();
  MachineFrameInfo *MFI    = MF.getFrameInfo();
  MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
  const MipsRegisterInfo *RegInfo =
    static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
  const MipsInstrInfo &TII =
    *static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
  bool isPIC = (MF.getTarget().getRelocationModel() == Reloc::PIC_);
  unsigned NewReg = 0;
  int NewImm = 0;
  bool ATUsed;

  // First, compute final stack size.
  unsigned RegSize = STI.isGP32bit() ? 4 : 8;
  unsigned StackAlign = getStackAlignment();
  unsigned LocalVarAreaOffset = MipsFI->needGPSaveRestore() ? 
    (MFI->getObjectOffset(MipsFI->getGPFI()) + RegSize) :
    MipsFI->getMaxCallFrameSize();
  unsigned StackSize = AlignOffset(LocalVarAreaOffset, StackAlign) +
    AlignOffset(MFI->getStackSize(), StackAlign);

   // Update stack size
  MFI->setStackSize(StackSize); 
  
  BuildMI(MBB, MBBI, dl, TII.get(Mips::NOREORDER));

  // TODO: check need from GP here.
  if (isPIC && STI.isABI_O32())
    BuildMI(MBB, MBBI, dl, TII.get(Mips::CPLOAD))
      .addReg(RegInfo->getPICCallReg());
  BuildMI(MBB, MBBI, dl, TII.get(Mips::NOMACRO));

  // No need to allocate space on the stack.
  if (StackSize == 0 && !MFI->adjustsStack()) return;

  // Adjust stack : addi sp, sp, (-imm)
  ATUsed = expandRegLargeImmPair(Mips::SP, -StackSize, NewReg, NewImm, MBB,
                                 MBBI);
  BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDiu), Mips::SP)
    .addReg(NewReg).addImm(NewImm);

  // FIXME: change this when mips goes MC".
  if (ATUsed)
    BuildMI(MBB, MBBI, dl, TII.get(Mips::ATMACRO));

  // Find the instruction past the last instruction that saves a callee-saved
  // register to the stack.
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
  
  for (unsigned i = 0; i < CSI.size(); ++i)
    ++MBBI;
 
  // if framepointer enabled, set it to point to the stack pointer.
  if (hasFP(MF))
    // Insert instruction "move $fp, $sp" at this location.    
    BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDu), Mips::FP)
      .addReg(Mips::SP).addReg(Mips::ZERO);

  // Restore GP from the saved stack location
  if (MipsFI->needGPSaveRestore())
    BuildMI(MBB, MBBI, dl, TII.get(Mips::CPRESTORE))
      .addImm(MFI->getObjectOffset(MipsFI->getGPFI()));

  // EH Frame infomation.
  MachineModuleInfo &MMI = MF.getMMI();
  std::vector<MachineMove> &Moves = MMI.getFrameMoves();
  MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::PROLOG_LABEL)).addSym(FrameLabel);

  if (hasFP(MF)) {
    MachineLocation SPDst(Mips::FP);
    MachineLocation SPSrc(Mips::SP);
    Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc)); 
  }
    
  if (StackSize) {
    MachineLocation SPDst(MachineLocation::VirtualFP);
    MachineLocation SPSrc(MachineLocation::VirtualFP, -StackSize);
    Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc)); 
  }

  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
       E = CSI.end(); I != E; ++I) {
    int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
    MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
    MachineLocation CSSrc(I->getReg());
    Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
  }        
}
Ejemplo n.º 17
0
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
/// abstract stack objects.
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
  const TargetFrameInfo &TFI = *Fn.getTarget().getFrameInfo();

  bool StackGrowsDown =
    TFI.getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;

  // Loop over all of the stack objects, assigning sequential addresses...
  MachineFrameInfo *MFI = Fn.getFrameInfo();

  // Start at the beginning of the local area.
  // The Offset is the distance from the stack top in the direction
  // of stack growth -- so it's always nonnegative.
  int LocalAreaOffset = TFI.getOffsetOfLocalArea();
  if (StackGrowsDown)
    LocalAreaOffset = -LocalAreaOffset;
  assert(LocalAreaOffset >= 0
         && "Local area offset should be in direction of stack growth");
  int64_t Offset = LocalAreaOffset;

  // If there are fixed sized objects that are preallocated in the local area,
  // non-fixed objects can't be allocated right at the start of local area.
  // We currently don't support filling in holes in between fixed sized
  // objects, so we adjust 'Offset' to point to the end of last fixed sized
  // preallocated object.
  for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
    int64_t FixedOff;
    if (StackGrowsDown) {
      // The maximum distance from the stack pointer is at lower address of
      // the object -- which is given by offset. For down growing stack
      // the offset is negative, so we negate the offset to get the distance.
      FixedOff = -MFI->getObjectOffset(i);
    } else {
      // The maximum distance from the start pointer is at the upper
      // address of the object.
      FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i);
    }
    if (FixedOff > Offset) Offset = FixedOff;
  }

  // First assign frame offsets to stack objects that are used to spill
  // callee saved registers.
  if (StackGrowsDown) {
    for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
      // If the stack grows down, we need to add the size to find the lowest
      // address of the object.
      Offset += MFI->getObjectSize(i);

      unsigned Align = MFI->getObjectAlignment(i);
      // Adjust to alignment boundary
      Offset = (Offset+Align-1)/Align*Align;

      MFI->setObjectOffset(i, -Offset);        // Set the computed offset
    }
  } else {
    int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex;
    for (int i = MaxCSFI; i >= MinCSFI ; --i) {
      unsigned Align = MFI->getObjectAlignment(i);
      // Adjust to alignment boundary
      Offset = (Offset+Align-1)/Align*Align;

      MFI->setObjectOffset(i, Offset);
      Offset += MFI->getObjectSize(i);
    }
  }

  unsigned MaxAlign = MFI->getMaxAlignment();

  // Make sure the special register scavenging spill slot is closest to the
  // frame pointer if a frame pointer is required.
  const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
  if (RS && RegInfo->hasFP(Fn) && !RegInfo->needsStackRealignment(Fn)) {
    int SFI = RS->getScavengingFrameIndex();
    if (SFI >= 0)
      AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
  }

  // Make sure that the stack protector comes before the local variables on the
  // stack.
  if (MFI->getStackProtectorIndex() >= 0)
    AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown,
                      Offset, MaxAlign);

  // Then assign frame offsets to stack objects that are not used to spill
  // callee saved registers.
  for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
    if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
      continue;
    if (RS && (int)i == RS->getScavengingFrameIndex())
      continue;
    if (MFI->isDeadObjectIndex(i))
      continue;
    if (MFI->getStackProtectorIndex() == (int)i)
      continue;

    AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
  }

  // Make sure the special register scavenging spill slot is closest to the
  // stack pointer.
  if (RS && (!RegInfo->hasFP(Fn) || RegInfo->needsStackRealignment(Fn))) {
    int SFI = RS->getScavengingFrameIndex();
    if (SFI >= 0)
      AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
  }

  if (!RegInfo->targetHandlesStackFrameRounding()) {
    // If we have reserved argument space for call sites in the function
    // immediately on entry to the current function, count it as part of the
    // overall stack size.
    if (MFI->adjustsStack() && RegInfo->hasReservedCallFrame(Fn))
      Offset += MFI->getMaxCallFrameSize();

    // Round up the size to a multiple of the alignment.  If the function has
    // any calls or alloca's, align to the target's StackAlignment value to
    // ensure that the callee's frame or the alloca data is suitably aligned;
    // otherwise, for leaf functions, align to the TransientStackAlignment
    // value.
    unsigned StackAlign;
    if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
        (RegInfo->needsStackRealignment(Fn) && MFI->getObjectIndexEnd() != 0))
      StackAlign = TFI.getStackAlignment();
    else
      StackAlign = TFI.getTransientStackAlignment();

    // If the frame pointer is eliminated, all frame offsets will be relative to
    // SP not FP. Align to MaxAlign so this works.
    StackAlign = std::max(StackAlign, MaxAlign);
    unsigned AlignMask = StackAlign - 1;
    Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
  }

  // Update frame info to pretend that this is part of the stack...
  MFI->setStackSize(Offset - LocalAreaOffset);
}
void MipsSEFrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB   = MF.front();
  MachineFrameInfo *MFI    = MF.getFrameInfo();
  MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();

  const MipsSEInstrInfo &TII =
    *static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
  const MipsRegisterInfo &RegInfo =
    *static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());

  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
  unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
  unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
  unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
  unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;

  // First, compute final stack size.
  uint64_t StackSize = MFI->getStackSize();

  // No need to allocate space on the stack.
  if (StackSize == 0 && !MFI->adjustsStack()) return;

  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  MachineLocation DstML, SrcML;

  // Adjust stack.
  TII.adjustStackPtr(SP, -StackSize, MBB, MBBI);

  // emit ".cfi_def_cfa_offset StackSize"
  MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
  BuildMI(MBB, MBBI, dl,
          TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
  MMI.addFrameInst(
      MCCFIInstruction::createDefCfaOffset(AdjustSPLabel, -StackSize));

  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

  if (CSI.size()) {
    // Find the instruction past the last instruction that saves a callee-saved
    // register to the stack.
    for (unsigned i = 0; i < CSI.size(); ++i)
      ++MBBI;

    // Iterate over list of callee-saved registers and emit .cfi_offset
    // directives.
    MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);

    for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
           E = CSI.end(); I != E; ++I) {
      int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
      unsigned Reg = I->getReg();

      // If Reg is a double precision register, emit two cfa_offsets,
      // one for each of the paired single precision registers.
      if (Mips::AFGR64RegClass.contains(Reg)) {
        unsigned Reg0 =
            MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_fpeven), true);
        unsigned Reg1 =
            MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_fpodd), true);

        if (!STI.isLittle())
          std::swap(Reg0, Reg1);

        MMI.addFrameInst(
            MCCFIInstruction::createOffset(CSLabel, Reg0, Offset));
        MMI.addFrameInst(
            MCCFIInstruction::createOffset(CSLabel, Reg1, Offset + 4));
      } else {
        // Reg is either in GPR32 or FGR32.
        MMI.addFrameInst(MCCFIInstruction::createOffset(
            CSLabel, MRI->getDwarfRegNum(Reg, 1), Offset));
      }
    }
  }

  if (MipsFI->callsEhReturn()) {
    const TargetRegisterClass *RC = STI.isABI_N64() ?
        &Mips::GPR64RegClass : &Mips::GPR32RegClass;

    // Insert instructions that spill eh data registers.
    for (int I = 0; I < 4; ++I) {
      if (!MBB.isLiveIn(ehDataReg(I)))
        MBB.addLiveIn(ehDataReg(I));
      TII.storeRegToStackSlot(MBB, MBBI, ehDataReg(I), false,
                              MipsFI->getEhDataRegFI(I), RC, &RegInfo);
    }

    // Emit .cfi_offset directives for eh data registers.
    MCSymbol *CSLabel2 = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel2);
    for (int I = 0; I < 4; ++I) {
      int64_t Offset = MFI->getObjectOffset(MipsFI->getEhDataRegFI(I));
      unsigned Reg = MRI->getDwarfRegNum(ehDataReg(I), true);
      MMI.addFrameInst(MCCFIInstruction::createOffset(CSLabel2, Reg, Offset));
    }
  }

  // if framepointer enabled, set it to point to the stack pointer.
  if (hasFP(MF)) {
    // Insert instruction "move $fp, $sp" at this location.
    BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO);

    // emit ".cfi_def_cfa_register $fp"
    MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel);
    MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
        SetFPLabel, MRI->getDwarfRegNum(FP, true)));
  }
}
void Thumb1FrameLowering::emitPrologue(MachineFunction &MF,
                                       MachineBasicBlock &MBB) const {
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo  *MFI = MF.getFrameInfo();
  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  const ThumbRegisterInfo *RegInfo =
      static_cast<const ThumbRegisterInfo *>(STI.getRegisterInfo());
  const Thumb1InstrInfo &TII =
      *static_cast<const Thumb1InstrInfo *>(STI.getInstrInfo());

  unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize();
  unsigned NumBytes = MFI->getStackSize();
  assert(NumBytes >= ArgRegsSaveSize &&
         "ArgRegsSaveSize is included in NumBytes");
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

  // Debug location must be unknown since the first debug location is used
  // to determine the end of the prologue.
  DebugLoc dl;
  
  unsigned FramePtr = RegInfo->getFrameRegister(MF);
  unsigned BasePtr = RegInfo->getBaseRegister();
  int CFAOffset = 0;

  // Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
  NumBytes = (NumBytes + 3) & ~3;
  MFI->setStackSize(NumBytes);

  // Determine the sizes of each callee-save spill areas and record which frame
  // belongs to which callee-save spill areas.
  unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
  int FramePtrSpillFI = 0;

  if (ArgRegsSaveSize) {
    emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -ArgRegsSaveSize,
                 MachineInstr::FrameSetup);
    CFAOffset -= ArgRegsSaveSize;
    unsigned CFIIndex = MMI.addFrameInst(
        MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
    BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex)
        .setMIFlags(MachineInstr::FrameSetup);
  }

  if (!AFI->hasStackFrame()) {
    if (NumBytes - ArgRegsSaveSize != 0) {
      emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -(NumBytes - ArgRegsSaveSize),
                   MachineInstr::FrameSetup);
      CFAOffset -= NumBytes - ArgRegsSaveSize;
      unsigned CFIIndex = MMI.addFrameInst(
          MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex)
          .setMIFlags(MachineInstr::FrameSetup);
    }
    return;
  }

  for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
    unsigned Reg = CSI[i].getReg();
    int FI = CSI[i].getFrameIdx();
    switch (Reg) {
    case ARM::R8:
    case ARM::R9:
    case ARM::R10:
    case ARM::R11:
      if (STI.isTargetMachO()) {
        GPRCS2Size += 4;
        break;
      }
      // fallthrough
    case ARM::R4:
    case ARM::R5:
    case ARM::R6:
    case ARM::R7:
    case ARM::LR:
      if (Reg == FramePtr)
        FramePtrSpillFI = FI;
      GPRCS1Size += 4;
      break;
    default:
      DPRCSSize += 8;
    }
  }

  if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) {
    ++MBBI;
  }

  // Determine starting offsets of spill areas.
  unsigned DPRCSOffset  = NumBytes - ArgRegsSaveSize - (GPRCS1Size + GPRCS2Size + DPRCSSize);
  unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
  unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
  bool HasFP = hasFP(MF);
  if (HasFP)
    AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
                                NumBytes);
  AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
  AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
  AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
  NumBytes = DPRCSOffset;

  int FramePtrOffsetInBlock = 0;
  unsigned adjustedGPRCS1Size = GPRCS1Size;
  if (tryFoldSPUpdateIntoPushPop(STI, MF, std::prev(MBBI), NumBytes)) {
    FramePtrOffsetInBlock = NumBytes;
    adjustedGPRCS1Size += NumBytes;
    NumBytes = 0;
  }

  if (adjustedGPRCS1Size) {
    CFAOffset -= adjustedGPRCS1Size;
    unsigned CFIIndex = MMI.addFrameInst(
        MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
    BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex)
        .setMIFlags(MachineInstr::FrameSetup);
  }
  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
         E = CSI.end(); I != E; ++I) {
    unsigned Reg = I->getReg();
    int FI = I->getFrameIdx();
    switch (Reg) {
    case ARM::R8:
    case ARM::R9:
    case ARM::R10:
    case ARM::R11:
    case ARM::R12:
      if (STI.isTargetMachO())
        break;
      // fallthough
    case ARM::R0:
    case ARM::R1:
    case ARM::R2:
    case ARM::R3:
    case ARM::R4:
    case ARM::R5:
    case ARM::R6:
    case ARM::R7:
    case ARM::LR:
      unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
          nullptr, MRI->getDwarfRegNum(Reg, true), MFI->getObjectOffset(FI)));
      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex)
          .setMIFlags(MachineInstr::FrameSetup);
      break;
    }
  }

  // Adjust FP so it point to the stack slot that contains the previous FP.
  if (HasFP) {
    FramePtrOffsetInBlock +=
        MFI->getObjectOffset(FramePtrSpillFI) + GPRCS1Size + ArgRegsSaveSize;
    AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr)
      .addReg(ARM::SP).addImm(FramePtrOffsetInBlock / 4)
      .setMIFlags(MachineInstr::FrameSetup));
    if(FramePtrOffsetInBlock) {
      CFAOffset += FramePtrOffsetInBlock;
      unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfa(
          nullptr, MRI->getDwarfRegNum(FramePtr, true), CFAOffset));
      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex)
          .setMIFlags(MachineInstr::FrameSetup);
    } else {
      unsigned CFIIndex =
          MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
              nullptr, MRI->getDwarfRegNum(FramePtr, true)));
      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex)
          .setMIFlags(MachineInstr::FrameSetup);
    }
    if (NumBytes > 508)
      // If offset is > 508 then sp cannot be adjusted in a single instruction,
      // try restoring from fp instead.
      AFI->setShouldRestoreSPFromFP(true);
  }

  if (NumBytes) {
    // Insert it after all the callee-save spills.
    emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
                 MachineInstr::FrameSetup);
    if (!HasFP) {
      CFAOffset -= NumBytes;
      unsigned CFIIndex = MMI.addFrameInst(
          MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex)
          .setMIFlags(MachineInstr::FrameSetup);
    }
  }

  if (STI.isTargetELF() && HasFP)
    MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
                             AFI->getFramePtrSpillOffset());

  AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
  AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
  AFI->setDPRCalleeSavedAreaSize(DPRCSSize);

  // Thumb1 does not currently support dynamic stack realignment.  Report a
  // fatal error rather then silently generate bad code.
  if (RegInfo->needsStackRealignment(MF))
      report_fatal_error("Dynamic stack realignment not supported for thumb1.");

  // If we need a base pointer, set it up here. It's whatever the value
  // of the stack pointer is at this point. Any variable size objects
  // will be allocated after this, so we can still use the base pointer
  // to reference locals.
  if (RegInfo->hasBasePointer(MF))
    AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), BasePtr)
                   .addReg(ARM::SP));

  // If the frame has variable sized objects then the epilogue must restore
  // the sp from fp. We can assume there's an FP here since hasFP already
  // checks for hasVarSizedObjects.
  if (MFI->hasVarSizedObjects())
    AFI->setShouldRestoreSPFromFP(true);
}
Ejemplo n.º 20
0
void XCoreFrameLowering::emitEpilogue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
  const XCoreInstrInfo &TII = *MF.getSubtarget<XCoreSubtarget>().getInstrInfo();
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  DebugLoc dl = MBBI->getDebugLoc();
  unsigned RetOpcode = MBBI->getOpcode();

  // Work out frame sizes.
  // We will adjust the SP in stages towards the final FrameSize.
  int RemainingAdj = MFI->getStackSize();
  assert(RemainingAdj%4 == 0 && "Misaligned frame size");
  RemainingAdj /= 4;

  if (RetOpcode == XCore::EH_RETURN) {
    // 'Restore' the exception info the unwinder has placed into the stack
    // slots.
    SmallVector<StackSlotInfo,2> SpillList;
    GetEHSpillList(SpillList, MFI, XFI, MF.getSubtarget().getTargetLowering());
    RestoreSpillList(MBB, MBBI, dl, TII, RemainingAdj, SpillList);

    // Return to the landing pad.
    unsigned EhStackReg = MBBI->getOperand(0).getReg();
    unsigned EhHandlerReg = MBBI->getOperand(1).getReg();
    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r)).addReg(EhStackReg);
    BuildMI(MBB, MBBI, dl, TII.get(XCore::BAU_1r)).addReg(EhHandlerReg);
    MBB.erase(MBBI);  // Erase the previous return instruction.
    return;
  }

  bool restoreLR = XFI->hasLRSpillSlot();
  bool UseRETSP = restoreLR && RemainingAdj
                  && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0);
  if (UseRETSP)
    restoreLR = false;
  bool FP = hasFP(MF);

  if (FP) // Restore the stack pointer.
    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r)).addReg(FramePtr);

  // If necessary, restore LR and FP from the stack, as we EXTSP.
  SmallVector<StackSlotInfo,2> SpillList;
  GetSpillList(SpillList, MFI, XFI, restoreLR, FP);
  RestoreSpillList(MBB, MBBI, dl, TII, RemainingAdj, SpillList);

  if (RemainingAdj) {
    // Complete all but one of the remaining Stack adjustments.
    IfNeededLDAWSP(MBB, MBBI, dl, TII, 0, RemainingAdj);
    if (UseRETSP) {
      // Fold prologue into return instruction
      assert(RetOpcode == XCore::RETSP_u6
             || RetOpcode == XCore::RETSP_lu6);
      int Opcode = isImmU6(RemainingAdj) ? XCore::RETSP_u6 : XCore::RETSP_lu6;
      MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opcode))
                                  .addImm(RemainingAdj);
      for (unsigned i = 3, e = MBBI->getNumOperands(); i < e; ++i)
        MIB->addOperand(MBBI->getOperand(i)); // copy any variadic operands
      MBB.erase(MBBI);  // Erase the previous return instruction.
    } else {
      int Opcode = isImmU6(RemainingAdj) ? XCore::LDAWSP_ru6 :
                                           XCore::LDAWSP_lru6;
      BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(RemainingAdj);
      // Don't erase the return instruction.
    }
  } // else Don't erase the return instruction.
}
Ejemplo n.º 21
0
void MipsFrameInfo::adjustMipsStackFrame(MachineFunction &MF) const {
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
  unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
  unsigned RegSize = STI.isGP32bit() ? 4 : 8;
  bool HasGP = MipsFI->needGPSaveRestore();

  // Min and Max CSI FrameIndex.
  int MinCSFI = -1, MaxCSFI = -1;

  // See the description at MipsMachineFunction.h
  int TopCPUSavedRegOff = -1, TopFPUSavedRegOff = -1;

  // Replace the dummy '0' SPOffset by the negative offsets, as explained on
  // LowerFormalArguments. Leaving '0' for while is necessary to avoid the
  // approach done by calculateFrameObjectOffsets to the stack frame.
  MipsFI->adjustLoadArgsFI(MFI);
  MipsFI->adjustStoreVarArgsFI(MFI);

  // It happens that the default stack frame allocation order does not directly
  // map to the convention used for mips. So we must fix it. We move the callee
  // save register slots after the local variables area, as described in the
  // stack frame above.
  unsigned CalleeSavedAreaSize = 0;
  if (!CSI.empty()) {
    MinCSFI = CSI[0].getFrameIdx();
    MaxCSFI = CSI[CSI.size()-1].getFrameIdx();
  }
  for (unsigned i = 0, e = CSI.size(); i != e; ++i)
    CalleeSavedAreaSize += MFI->getObjectAlignment(CSI[i].getFrameIdx());

  unsigned StackOffset = HasGP ? (MipsFI->getGPStackOffset()+RegSize)
                : (STI.isABI_O32() ? 16 : 0);

  // Adjust local variables. They should come on the stack right
  // after the arguments.
  int LastOffsetFI = -1;
  for (int i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
    if (i >= MinCSFI && i <= MaxCSFI)
      continue;
    if (MFI->isDeadObjectIndex(i))
      continue;
    unsigned Offset =
      StackOffset + MFI->getObjectOffset(i) - CalleeSavedAreaSize;
    if (LastOffsetFI == -1)
      LastOffsetFI = i;
    if (Offset > MFI->getObjectOffset(LastOffsetFI))
      LastOffsetFI = i;
    MFI->setObjectOffset(i, Offset);
  }

  // Adjust CPU Callee Saved Registers Area. Registers RA and FP must
  // be saved in this CPU Area. This whole area must be aligned to the
  // default Stack Alignment requirements.
  if (LastOffsetFI >= 0)
    StackOffset = MFI->getObjectOffset(LastOffsetFI)+
                  MFI->getObjectSize(LastOffsetFI);
  StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign);

  for (unsigned i = 0, e = CSI.size(); i != e ; ++i) {
    unsigned Reg = CSI[i].getReg();
    if (!Mips::CPURegsRegisterClass->contains(Reg))
      break;
    MFI->setObjectOffset(CSI[i].getFrameIdx(), StackOffset);
    TopCPUSavedRegOff = StackOffset;
    StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx());
  }

  // Stack locations for FP and RA. If only one of them is used,
  // the space must be allocated for both, otherwise no space at all.
  if (hasFP(MF) || MFI->adjustsStack()) {
    // FP stack location
    MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true),
                         StackOffset);
    MipsFI->setFPStackOffset(StackOffset);
    TopCPUSavedRegOff = StackOffset;
    StackOffset += RegSize;

    // SP stack location
    MFI->setObjectOffset(MFI->CreateStackObject(RegSize, RegSize, true),
                         StackOffset);
    MipsFI->setRAStackOffset(StackOffset);
    StackOffset += RegSize;

    if (MFI->adjustsStack())
      TopCPUSavedRegOff += RegSize;
  }

  StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign);

  // Adjust FPU Callee Saved Registers Area. This Area must be
  // aligned to the default Stack Alignment requirements.
  for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
    unsigned Reg = CSI[i].getReg();
    if (Mips::CPURegsRegisterClass->contains(Reg))
      continue;
    MFI->setObjectOffset(CSI[i].getFrameIdx(), StackOffset);
    TopFPUSavedRegOff = StackOffset;
    StackOffset += MFI->getObjectAlignment(CSI[i].getFrameIdx());
  }
  StackOffset = ((StackOffset+StackAlign-1)/StackAlign*StackAlign);

  // Update frame info
  MFI->setStackSize(StackOffset);

  // Recalculate the final tops offset. The final values must be '0'
  // if there isn't a callee saved register for CPU or FPU, otherwise
  // a negative offset is needed.
  if (TopCPUSavedRegOff >= 0)
    MipsFI->setCPUTopSavedRegOff(TopCPUSavedRegOff-StackOffset);

  if (TopFPUSavedRegOff >= 0)
    MipsFI->setFPUTopSavedRegOff(TopFPUSavedRegOff-StackOffset);
}
Ejemplo n.º 22
0
void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB = MF.front();
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo  *MFI = MF.getFrameInfo();
  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
  const Thumb1RegisterInfo *RegInfo =
    static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo());
  const Thumb1InstrInfo &TII =
    *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo());

  unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
  unsigned NumBytes = MFI->getStackSize();
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
  unsigned FramePtr = RegInfo->getFrameRegister(MF);
  unsigned BasePtr = RegInfo->getBaseRegister();

  // Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
  NumBytes = (NumBytes + 3) & ~3;
  MFI->setStackSize(NumBytes);

  // Determine the sizes of each callee-save spill areas and record which frame
  // belongs to which callee-save spill areas.
  unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
  int FramePtrSpillFI = 0;

  if (VARegSaveSize)
    emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -VARegSaveSize,
                 MachineInstr::FrameSetup);

  if (!AFI->hasStackFrame()) {
    if (NumBytes != 0)
      emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
                   MachineInstr::FrameSetup);
    return;
  }

  for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
    unsigned Reg = CSI[i].getReg();
    int FI = CSI[i].getFrameIdx();
    switch (Reg) {
    case ARM::R4:
    case ARM::R5:
    case ARM::R6:
    case ARM::R7:
    case ARM::LR:
      if (Reg == FramePtr)
        FramePtrSpillFI = FI;
      AFI->addGPRCalleeSavedArea1Frame(FI);
      GPRCS1Size += 4;
      break;
    case ARM::R8:
    case ARM::R9:
    case ARM::R10:
    case ARM::R11:
      if (Reg == FramePtr)
        FramePtrSpillFI = FI;
      if (STI.isTargetDarwin()) {
        AFI->addGPRCalleeSavedArea2Frame(FI);
        GPRCS2Size += 4;
      } else {
        AFI->addGPRCalleeSavedArea1Frame(FI);
        GPRCS1Size += 4;
      }
      break;
    default:
      AFI->addDPRCalleeSavedAreaFrame(FI);
      DPRCSSize += 8;
    }
  }

  if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) {
    ++MBBI;
    if (MBBI != MBB.end())
      dl = MBBI->getDebugLoc();
  }

  // Determine starting offsets of spill areas.
  unsigned DPRCSOffset  = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
  unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
  unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
  AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
  AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
  AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
  AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
  NumBytes = DPRCSOffset;

  // Adjust FP so it point to the stack slot that contains the previous FP.
  if (hasFP(MF)) {
    AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr)
      .addFrameIndex(FramePtrSpillFI).addImm(0)
      .setMIFlags(MachineInstr::FrameSetup));
    if (NumBytes > 508)
      // If offset is > 508 then sp cannot be adjusted in a single instruction,
      // try restoring from fp instead.
      AFI->setShouldRestoreSPFromFP(true);
  }

  if (NumBytes)
    // Insert it after all the callee-save spills.
    emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
                 MachineInstr::FrameSetup);

  if (STI.isTargetELF() && hasFP(MF))
    MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
                             AFI->getFramePtrSpillOffset());

  AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
  AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
  AFI->setDPRCalleeSavedAreaSize(DPRCSSize);

  // If we need a base pointer, set it up here. It's whatever the value
  // of the stack pointer is at this point. Any variable size objects
  // will be allocated after this, so we can still use the base pointer
  // to reference locals.
  if (RegInfo->hasBasePointer(MF))
    AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), BasePtr)
                   .addReg(ARM::SP));

  // If the frame has variable sized objects then the epilogue must restore
  // the sp from fp. We can assume there's an FP here since hasFP already
  // checks for hasVarSizedObjects.
  if (MFI->hasVarSizedObjects())
    AFI->setShouldRestoreSPFromFP(true);
}
Ejemplo n.º 23
0
void MipsFrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB   = MF.front();
  MachineFrameInfo *MFI    = MF.getFrameInfo();
  MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
  const MipsRegisterInfo *RegInfo =
    static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
  const MipsInstrInfo &TII =
    *static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
  bool isPIC = (MF.getTarget().getRelocationModel() == Reloc::PIC_);
  unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
  unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
  unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
  unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;
  unsigned ADDiu = STI.isABI_N64() ? Mips::DADDiu : Mips::ADDiu;

  // First, compute final stack size.
  unsigned RegSize = STI.isGP32bit() ? 4 : 8;
  unsigned StackAlign = getStackAlignment();
  unsigned LocalVarAreaOffset = MipsFI->needGPSaveRestore() ?
    (MFI->getObjectOffset(MipsFI->getGPFI()) + RegSize) :
    MipsFI->getMaxCallFrameSize();
  uint64_t StackSize =  RoundUpToAlignment(LocalVarAreaOffset, StackAlign) +
     RoundUpToAlignment(MFI->getStackSize(), StackAlign);

   // Update stack size
  MFI->setStackSize(StackSize);

  // Emit instructions that set the global base register if the target ABI is
  // O32.
  if (isPIC && MipsFI->globalBaseRegSet() && STI.isABI_O32() &&
      !MipsFI->globalBaseRegFixed()) {
      // See MipsInstrInfo.td for explanation.
    MachineBasicBlock *NewEntry = MF.CreateMachineBasicBlock();
    MF.insert(&MBB, NewEntry);
    NewEntry->addSuccessor(&MBB);

    // Copy live in registers.
    for (MachineBasicBlock::livein_iterator R = MBB.livein_begin();
         R != MBB.livein_end(); ++R)
      NewEntry->addLiveIn(*R);

    BuildMI(*NewEntry, NewEntry->begin(), dl, TII.get(Mips:: SETGP01),
            Mips::V0);
  }

  // No need to allocate space on the stack.
  if (StackSize == 0 && !MFI->adjustsStack()) return;

  MachineModuleInfo &MMI = MF.getMMI();
  std::vector<MachineMove> &Moves = MMI.getFrameMoves();
  MachineLocation DstML, SrcML;

  // Adjust stack.
  if (isInt<16>(-StackSize)) // addi sp, sp, (-stacksize)
    BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(-StackSize);
  else { // Expand immediate that doesn't fit in 16-bit.
    MipsFI->setEmitNOAT();
    expandLargeImm(SP, -StackSize, STI.isABI_N64(), TII, MBB, MBBI, dl);
  }

  // emit ".cfi_def_cfa_offset StackSize"
  MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
  BuildMI(MBB, MBBI, dl,
          TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
  DstML = MachineLocation(MachineLocation::VirtualFP);
  SrcML = MachineLocation(MachineLocation::VirtualFP, -StackSize);
  Moves.push_back(MachineMove(AdjustSPLabel, DstML, SrcML));

  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

  if (CSI.size()) {
    // Find the instruction past the last instruction that saves a callee-saved
    // register to the stack.
    for (unsigned i = 0; i < CSI.size(); ++i)
      ++MBBI;

    // Iterate over list of callee-saved registers and emit .cfi_offset
    // directives.
    MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);

    for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
           E = CSI.end(); I != E; ++I) {
      int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
      unsigned Reg = I->getReg();

      // If Reg is a double precision register, emit two cfa_offsets,
      // one for each of the paired single precision registers.
      if (Mips::AFGR64RegisterClass->contains(Reg)) {
        const uint16_t *SubRegs = RegInfo->getSubRegisters(Reg);
        MachineLocation DstML0(MachineLocation::VirtualFP, Offset);
        MachineLocation DstML1(MachineLocation::VirtualFP, Offset + 4);
        MachineLocation SrcML0(*SubRegs);
        MachineLocation SrcML1(*(SubRegs + 1));

        if (!STI.isLittle())
          std::swap(SrcML0, SrcML1);

        Moves.push_back(MachineMove(CSLabel, DstML0, SrcML0));
        Moves.push_back(MachineMove(CSLabel, DstML1, SrcML1));
      }
      else {
        // Reg is either in CPURegs or FGR32.
        DstML = MachineLocation(MachineLocation::VirtualFP, Offset);
        SrcML = MachineLocation(Reg);
        Moves.push_back(MachineMove(CSLabel, DstML, SrcML));
      }
    }
  }

  // if framepointer enabled, set it to point to the stack pointer.
  if (hasFP(MF)) {
    // Insert instruction "move $fp, $sp" at this location.
    BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO);

    // emit ".cfi_def_cfa_register $fp"
    MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel);
    DstML = MachineLocation(FP);
    SrcML = MachineLocation(MachineLocation::VirtualFP);
    Moves.push_back(MachineMove(SetFPLabel, DstML, SrcML));
  }

  // Restore GP from the saved stack location
  if (MipsFI->needGPSaveRestore()) {
    unsigned Offset = MFI->getObjectOffset(MipsFI->getGPFI());
    BuildMI(MBB, MBBI, dl, TII.get(Mips::CPRESTORE)).addImm(Offset)
      .addReg(Mips::GP);
  }
}
Ejemplo n.º 24
0
void XCoreFrameLowering::emitPrologue(MachineFunction &MF,
                                      MachineBasicBlock &MBB) const {
  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo *MMI = &MF.getMMI();
  const MCRegisterInfo *MRI = MMI->getContext().getRegisterInfo();
  const XCoreInstrInfo &TII = *MF.getSubtarget<XCoreSubtarget>().getInstrInfo();
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  // Debug location must be unknown since the first debug location is used
  // to determine the end of the prologue.
  DebugLoc dl;

  if (MFI->getMaxAlignment() > getStackAlignment())
    report_fatal_error("emitPrologue unsupported alignment: "
                       + Twine(MFI->getMaxAlignment()));

  const AttributeSet &PAL = MF.getFunction()->getAttributes();
  if (PAL.hasAttrSomewhere(Attribute::Nest))
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDWSP_ru6), XCore::R11).addImm(0);
    // FIX: Needs addMemOperand() but can't use getFixedStack() or getStack().

  // Work out frame sizes.
  // We will adjust the SP in stages towards the final FrameSize.
  assert(MFI->getStackSize()%4 == 0 && "Misaligned frame size");
  const int FrameSize = MFI->getStackSize() / 4;
  int Adjusted = 0;

  bool saveLR = XFI->hasLRSpillSlot();
  bool UseENTSP = saveLR && FrameSize
                  && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0);
  if (UseENTSP)
    saveLR = false;
  bool FP = hasFP(MF);
  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(MF);

  if (UseENTSP) {
    // Allocate space on the stack at the same time as saving LR.
    Adjusted = (FrameSize > MaxImmU16) ? MaxImmU16 : FrameSize;
    int Opcode = isImmU6(Adjusted) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
    MBB.addLiveIn(XCore::LR);
    MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opcode));
    MIB.addImm(Adjusted);
    MIB->addRegisterKilled(XCore::LR, MF.getSubtarget().getRegisterInfo(),
                           true);
    if (emitFrameMoves) {
      EmitDefCfaOffset(MBB, MBBI, dl, TII, MMI, Adjusted*4);
      unsigned DRegNum = MRI->getDwarfRegNum(XCore::LR, true);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI, DRegNum, 0);
    }
  }

  // If necessary, save LR and FP to the stack, as we EXTSP.
  SmallVector<StackSlotInfo,2> SpillList;
  GetSpillList(SpillList, MFI, XFI, saveLR, FP);
  // We want the nearest (negative) offsets first, so reverse list.
  std::reverse(SpillList.begin(), SpillList.end());
  for (unsigned i = 0, e = SpillList.size(); i != e; ++i) {
    assert(SpillList[i].Offset % 4 == 0 && "Misaligned stack offset");
    assert(SpillList[i].Offset <= 0 && "Unexpected positive stack offset");
    int OffsetFromTop = - SpillList[i].Offset/4;
    IfNeededExtSP(MBB, MBBI, dl, TII, MMI, OffsetFromTop, Adjusted, FrameSize,
                  emitFrameMoves);
    int Offset = Adjusted - OffsetFromTop;
    int Opcode = isImmU6(Offset) ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
    MBB.addLiveIn(SpillList[i].Reg);
    BuildMI(MBB, MBBI, dl, TII.get(Opcode))
      .addReg(SpillList[i].Reg, RegState::Kill)
      .addImm(Offset)
      .addMemOperand(getFrameIndexMMO(MBB, SpillList[i].FI,
                                      MachineMemOperand::MOStore));
    if (emitFrameMoves) {
      unsigned DRegNum = MRI->getDwarfRegNum(SpillList[i].Reg, true);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI, DRegNum, SpillList[i].Offset);
    }
  }

  // Complete any remaining Stack adjustment.
  IfNeededExtSP(MBB, MBBI, dl, TII, MMI, FrameSize, Adjusted, FrameSize,
                emitFrameMoves);
  assert(Adjusted==FrameSize && "IfNeededExtSP has not completed adjustment");

  if (FP) {
    // Set the FP from the SP.
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr).addImm(0);
    if (emitFrameMoves)
      EmitDefCfaRegister(MBB, MBBI, dl, TII, MMI,
                         MRI->getDwarfRegNum(FramePtr, true));
  }

  if (emitFrameMoves) {
    // Frame moves for callee saved.
    for (const auto &SpillLabel : XFI->getSpillLabels()) {
      MachineBasicBlock::iterator Pos = SpillLabel.first;
      ++Pos;
      const CalleeSavedInfo &CSI = SpillLabel.second;
      int Offset = MFI->getObjectOffset(CSI.getFrameIdx());
      unsigned DRegNum = MRI->getDwarfRegNum(CSI.getReg(), true);
      EmitCfiOffset(MBB, Pos, dl, TII, MMI, DRegNum, Offset);
    }
    if (XFI->hasEHSpillSlot()) {
      // The unwinder requires stack slot & CFI offsets for the exception info.
      // We do not save/spill these registers.
      SmallVector<StackSlotInfo,2> SpillList;
      GetEHSpillList(SpillList, MFI, XFI,
                     MF.getSubtarget().getTargetLowering());
      assert(SpillList.size()==2 && "Unexpected SpillList size");
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI,
                    MRI->getDwarfRegNum(SpillList[0].Reg, true),
                    SpillList[0].Offset);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI,
                    MRI->getDwarfRegNum(SpillList[1].Reg, true),
                    SpillList[1].Offset);
    }
  }
}
Ejemplo n.º 25
0
void Cpu0FrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB   = MF.front();
  MachineFrameInfo *MFI    = MF.getFrameInfo();
  Cpu0FunctionInfo *Cpu0FI = MF.getInfo<Cpu0FunctionInfo>();
  const Cpu0InstrInfo &TII =
    *static_cast<const Cpu0InstrInfo*>(MF.getTarget().getInstrInfo());
  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
  unsigned SP = Cpu0::SP;
 // lbd document - mark - Cpu0::SP
  unsigned FP = Cpu0::FP;
  unsigned ZERO = Cpu0::ZERO;
  unsigned ADDu = Cpu0::ADDu;
 // lbd document - mark - Cpu0::ADDu
  unsigned ADDiu = Cpu0::ADDiu;
  // First, compute final stack size.
  unsigned StackAlign = getStackAlignment();
  unsigned RegSize = 4;
  unsigned LocalVarAreaOffset = 
    Cpu0FI->needGPSaveRestore() ?
    (MFI->getObjectOffset(Cpu0FI->getGPFI()) + RegSize) :
    Cpu0FI->getMaxCallFrameSize();
  uint64_t StackSize =  RoundUpToAlignment(LocalVarAreaOffset, StackAlign) +
     RoundUpToAlignment(MFI->getStackSize(), StackAlign);

   // Update stack size
  MFI->setStackSize(StackSize);

  // No need to allocate space on the stack.
  if (StackSize == 0 && !MFI->adjustsStack()) return;

  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  MachineLocation DstML, SrcML;

  // Adjust stack.
  if (isInt<16>(-StackSize)) // addiu sp, sp, (-stacksize)
    BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(-StackSize);
  else { // Expand immediate that doesn't fit in 16-bit.
    Cpu0FI->setEmitNOAT();
    expandLargeImm(SP, -StackSize, TII, MBB, MBBI, dl);
  }

  // emit ".cfi_def_cfa_offset StackSize"
  MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
  BuildMI(MBB, MBBI, dl,
          TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
  MMI.addFrameInst(
      MCCFIInstruction::createDefCfaOffset(AdjustSPLabel, -StackSize));

  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

  if (CSI.size()) {
    // Find the instruction past the last instruction that saves a callee-saved
    // register to the stack.
    for (unsigned i = 0; i < CSI.size(); ++i)
      ++MBBI;

    // Iterate over list of callee-saved registers and emit .cfi_offset
    // directives.
    MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);

    for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
           E = CSI.end(); I != E; ++I) {
      int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
      unsigned Reg = I->getReg();
      {
        // Reg is in CPURegs.
        MMI.addFrameInst(MCCFIInstruction::createOffset(
            CSLabel, MRI->getDwarfRegNum(Reg, 1), Offset));
      }
    }
  }
  
  // if framepointer enabled, set it to point to the stack pointer.
  if (hasFP(MF)) {
    // Insert instruction "move $fp, $sp" at this location.
    BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO);

    // emit ".cfi_def_cfa_register $fp"
    MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl,
            TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel);
    MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
        SetFPLabel, MRI->getDwarfRegNum(FP, true)));
  }

  // Restore GP from the saved stack location
  if (Cpu0FI->needGPSaveRestore()) {
    unsigned Offset = MFI->getObjectOffset(Cpu0FI->getGPFI());
    BuildMI(MBB, MBBI, dl, TII.get(Cpu0::CPRESTORE)).addImm(Offset)
      .addReg(Cpu0::GP);
  } // lbd document - mark - if (Cpu0FI->needGPSaveRestore())
}
Ejemplo n.º 26
0
void SPURegisterInfo::emitPrologue(MachineFunction &MF) const
{
    MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
    MachineBasicBlock::iterator MBBI = MBB.begin();
    MachineFrameInfo *MFI = MF.getFrameInfo();
    MachineModuleInfo &MMI = MF.getMMI();
    DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

    // Prepare for debug frame info.
    bool hasDebugInfo = MMI.hasDebugInfo();
    MCSymbol *FrameLabel = 0;

    // Move MBBI back to the beginning of the function.
    MBBI = MBB.begin();

    // Work out frame sizes.
    determineFrameLayout(MF);
    int FrameSize = MFI->getStackSize();

    assert((FrameSize & 0xf) == 0
           && "SPURegisterInfo::emitPrologue: FrameSize not aligned");

    // the "empty" frame size is 16 - just the register scavenger spill slot
    if (FrameSize > 16 || MFI->adjustsStack()) {
        FrameSize = -(FrameSize + SPUFrameInfo::minStackSize());
        if (hasDebugInfo) {
            // Mark effective beginning of when frame pointer becomes valid.
            FrameLabel = MMI.getContext().CreateTempSymbol();
            BuildMI(MBB, MBBI, dl, TII.get(SPU::DBG_LABEL)).addSym(FrameLabel);
        }

        // Adjust stack pointer, spilling $lr -> 16($sp) and $sp -> -FrameSize($sp)
        // for the ABI
        BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R0).addImm(16)
        .addReg(SPU::R1);
        if (isInt<10>(FrameSize)) {
            // Spill $sp to adjusted $sp
            BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R1).addImm(FrameSize)
            .addReg(SPU::R1);
            // Adjust $sp by required amout
            BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1).addReg(SPU::R1)
            .addImm(FrameSize);
        } else if (isInt<16>(FrameSize)) {
            // Frame size can be loaded into ILr32n, so temporarily spill $r2 and use
            // $r2 to adjust $sp:
            BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2)
            .addImm(-16)
            .addReg(SPU::R1);
            BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2)
            .addImm(FrameSize);
            BuildMI(MBB, MBBI, dl, TII.get(SPU::STQXr32), SPU::R1)
            .addReg(SPU::R2)
            .addReg(SPU::R1);
            BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1)
            .addReg(SPU::R1)
            .addReg(SPU::R2);
            BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2)
            .addReg(SPU::R2)
            .addImm(16);
            BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2)
            .addReg(SPU::R2)
            .addReg(SPU::R1);
        } else {
            report_fatal_error("Unhandled frame size: " + Twine(FrameSize));
        }

        if (hasDebugInfo) {
            std::vector<MachineMove> &Moves = MMI.getFrameMoves();

            // Show update of SP.
            MachineLocation SPDst(MachineLocation::VirtualFP);
            MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize);
            Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));

            // Add callee saved registers to move list.
            const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
            for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
                int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
                unsigned Reg = CSI[I].getReg();
                if (Reg == SPU::R0) continue;
                MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
                MachineLocation CSSrc(Reg);
                Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
            }

            // Mark effective beginning of when frame pointer is ready.
            MCSymbol *ReadyLabel = MMI.getContext().CreateTempSymbol();
            BuildMI(MBB, MBBI, dl, TII.get(SPU::DBG_LABEL)).addSym(ReadyLabel);

            MachineLocation FPDst(SPU::R1);
            MachineLocation FPSrc(MachineLocation::VirtualFP);
            Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc));
        }
    } else {
        // This is a leaf function -- insert a branch hint iff there are
        // sufficient number instructions in the basic block. Note that
        // this is just a best guess based on the basic block's size.
        if (MBB.size() >= (unsigned) SPUFrameInfo::branchHintPenalty()) {
            MachineBasicBlock::iterator MBBI = prior(MBB.end());
            dl = MBBI->getDebugLoc();

            // Insert terminator label
            BuildMI(MBB, MBBI, dl, TII.get(SPU::DBG_LABEL))
            .addSym(MMI.getContext().CreateTempSymbol());
        }
    }
}
Ejemplo n.º 27
0
void AArch64FrameLowering::emitPrologue(MachineFunction &MF) const {
  AArch64MachineFunctionInfo *FuncInfo =
    MF.getInfo<AArch64MachineFunctionInfo>();
  MachineBasicBlock &MBB = MF.front();
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
  DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  bool NeedsFrameMoves = MMI.hasDebugInfo()
    || MF.getFunction()->needsUnwindTableEntry();

  uint64_t NumInitialBytes, NumResidualBytes;

  // Currently we expect the stack to be laid out by
  //     sub sp, sp, #initial
  //     stp x29, x30, [sp, #offset]
  //     ...
  //     str xxx, [sp, #offset]
  //     sub sp, sp, #rest (possibly via extra instructions).
  if (MFI->getCalleeSavedInfo().size()) {
    // If there are callee-saved registers, we want to store them efficiently as
    // a block, and virtual base assignment happens too early to do it for us so
    // we adjust the stack in two phases: first just for callee-saved fiddling,
    // then to allocate the rest of the frame.
    splitSPAdjustments(MFI->getStackSize(), NumInitialBytes, NumResidualBytes);
  } else {
    // If there aren't any callee-saved registers, two-phase adjustment is
    // inefficient. It's more efficient to adjust with NumInitialBytes too
    // because when we're in a "callee pops argument space" situation, that pop
    // must be tacked onto Initial for correctness.
    NumInitialBytes = MFI->getStackSize();
    NumResidualBytes = 0;
  }

  // Tell everyone else how much adjustment we're expecting them to use. In
  // particular if an adjustment is required for a tail call the epilogue could
  // have a different view of things.
  FuncInfo->setInitialStackAdjust(NumInitialBytes);

  emitSPUpdate(MBB, MBBI, DL, TII, AArch64::X16, -NumInitialBytes,
               MachineInstr::FrameSetup);

  if (NeedsFrameMoves && NumInitialBytes) {
    // We emit this update even if the CFA is set from a frame pointer later so
    // that the CFA is valid in the interim.
    MachineLocation Dst(MachineLocation::VirtualFP);
    unsigned Reg = MRI->getDwarfRegNum(AArch64::XSP, true);
    unsigned CFIIndex = MMI.addFrameInst(
        MCCFIInstruction::createDefCfa(nullptr, Reg, -NumInitialBytes));
    BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex);
  }

  // Otherwise we need to set the frame pointer and/or add a second stack
  // adjustment.

  bool FPNeedsSetting = hasFP(MF);
  for (; MBBI != MBB.end(); ++MBBI) {
    // Note that this search makes strong assumptions about the operation used
    // to store the frame-pointer: it must be "STP x29, x30, ...". This could
    // change in future, but until then there's no point in implementing
    // untestable more generic cases.
    if (FPNeedsSetting && MBBI->getOpcode() == AArch64::LSPair64_STR
                       && MBBI->getOperand(0).getReg() == AArch64::X29) {
      int64_t X29FrameIdx = MBBI->getOperand(2).getIndex();
      FuncInfo->setFramePointerOffset(MFI->getObjectOffset(X29FrameIdx));

      ++MBBI;
      emitRegUpdate(MBB, MBBI, DL, TII, AArch64::X29, AArch64::XSP,
                    AArch64::X29,
                    NumInitialBytes + MFI->getObjectOffset(X29FrameIdx),
                    MachineInstr::FrameSetup);

      // The offset adjustment used when emitting debugging locations relative
      // to whatever frame base is set. AArch64 uses the default frame base (FP
      // or SP) and this adjusts the calculations to be correct.
      MFI->setOffsetAdjustment(- MFI->getObjectOffset(X29FrameIdx)
                               - MFI->getStackSize());

      if (NeedsFrameMoves) {
        unsigned Reg = MRI->getDwarfRegNum(AArch64::X29, true);
        unsigned Offset = MFI->getObjectOffset(X29FrameIdx);
        unsigned CFIIndex = MMI.addFrameInst(
            MCCFIInstruction::createDefCfa(nullptr, Reg, Offset));
        BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
            .addCFIIndex(CFIIndex);
      }

      FPNeedsSetting = false;
    }

    if (!MBBI->getFlag(MachineInstr::FrameSetup))
      break;
  }

  assert(!FPNeedsSetting && "Frame pointer couldn't be set");

  emitSPUpdate(MBB, MBBI, DL, TII, AArch64::X16, -NumResidualBytes,
               MachineInstr::FrameSetup);

  // Now we emit the rest of the frame setup information, if necessary: we've
  // already noted the FP and initial SP moves so we're left with the prologue's
  // final SP update and callee-saved register locations.
  if (!NeedsFrameMoves)
    return;

  // The rest of the stack adjustment
  if (!hasFP(MF) && NumResidualBytes) {
    MachineLocation Dst(MachineLocation::VirtualFP);
    unsigned Reg = MRI->getDwarfRegNum(AArch64::XSP, true);
    unsigned Offset = NumResidualBytes + NumInitialBytes;
    unsigned CFIIndex =
        MMI.addFrameInst(MCCFIInstruction::createDefCfa(nullptr, Reg, -Offset));
    BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex);
  }

  // And any callee-saved registers (it's fine to leave them to the end here,
  // because the old values are still valid at this point.
  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
  if (CSI.size()) {
    for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
           E = CSI.end(); I != E; ++I) {
      unsigned Offset = MFI->getObjectOffset(I->getFrameIdx());
      unsigned Reg = MRI->getDwarfRegNum(I->getReg(), true);
      unsigned CFIIndex = MMI.addFrameInst(
          MCCFIInstruction::createOffset(nullptr, Reg, Offset));
      BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex);
    }
  }
}
Ejemplo n.º 28
0
void MipsSEFrameLowering::emitPrologue(MachineFunction &MF,
                                       MachineBasicBlock &MBB) const {
  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
  MachineFrameInfo *MFI    = MF.getFrameInfo();
  MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();

  const MipsSEInstrInfo &TII =
      *static_cast<const MipsSEInstrInfo *>(STI.getInstrInfo());
  const MipsRegisterInfo &RegInfo =
      *static_cast<const MipsRegisterInfo *>(STI.getRegisterInfo());

  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc dl;
  MipsABIInfo ABI = STI.getABI();
  unsigned SP = ABI.GetStackPtr();
  unsigned FP = ABI.GetFramePtr();
  unsigned ZERO = ABI.GetNullPtr();
  unsigned MOVE = ABI.GetGPRMoveOp();
  unsigned ADDiu = ABI.GetPtrAddiuOp();
  unsigned AND = ABI.IsN64() ? Mips::AND64 : Mips::AND;

  const TargetRegisterClass *RC = ABI.ArePtrs64bit() ?
        &Mips::GPR64RegClass : &Mips::GPR32RegClass;

  // First, compute final stack size.
  uint64_t StackSize = MFI->getStackSize();

  // No need to allocate space on the stack.
  if (StackSize == 0 && !MFI->adjustsStack()) return;

  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  MachineLocation DstML, SrcML;

  // Adjust stack.
  TII.adjustStackPtr(SP, -StackSize, MBB, MBBI);

  // emit ".cfi_def_cfa_offset StackSize"
  unsigned CFIIndex = MMI.addFrameInst(
      MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize));
  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
      .addCFIIndex(CFIIndex);

  if (MF.getFunction()->hasFnAttribute("interrupt"))
    emitInterruptPrologueStub(MF, MBB);

  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();

  if (CSI.size()) {
    // Find the instruction past the last instruction that saves a callee-saved
    // register to the stack.
    for (unsigned i = 0; i < CSI.size(); ++i)
      ++MBBI;

    // Iterate over list of callee-saved registers and emit .cfi_offset
    // directives.
    for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
           E = CSI.end(); I != E; ++I) {
      int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
      unsigned Reg = I->getReg();

      // If Reg is a double precision register, emit two cfa_offsets,
      // one for each of the paired single precision registers.
      if (Mips::AFGR64RegClass.contains(Reg)) {
        unsigned Reg0 =
            MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_lo), true);
        unsigned Reg1 =
            MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_hi), true);

        if (!STI.isLittle())
          std::swap(Reg0, Reg1);

        unsigned CFIIndex = MMI.addFrameInst(
            MCCFIInstruction::createOffset(nullptr, Reg0, Offset));
        BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
            .addCFIIndex(CFIIndex);

        CFIIndex = MMI.addFrameInst(
            MCCFIInstruction::createOffset(nullptr, Reg1, Offset + 4));
        BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
            .addCFIIndex(CFIIndex);
      } else if (Mips::FGR64RegClass.contains(Reg)) {
        unsigned Reg0 = MRI->getDwarfRegNum(Reg, true);
        unsigned Reg1 = MRI->getDwarfRegNum(Reg, true) + 1;

        if (!STI.isLittle())
          std::swap(Reg0, Reg1);

        unsigned CFIIndex = MMI.addFrameInst(
          MCCFIInstruction::createOffset(nullptr, Reg0, Offset));
        BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
            .addCFIIndex(CFIIndex);

        CFIIndex = MMI.addFrameInst(
          MCCFIInstruction::createOffset(nullptr, Reg1, Offset + 4));
        BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
            .addCFIIndex(CFIIndex);
      } else {
        // Reg is either in GPR32 or FGR32.
        unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
            nullptr, MRI->getDwarfRegNum(Reg, 1), Offset));
        BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
            .addCFIIndex(CFIIndex);
      }
    }
  }

  if (MipsFI->callsEhReturn()) {
    // Insert instructions that spill eh data registers.
    for (int I = 0; I < 4; ++I) {
      if (!MBB.isLiveIn(ABI.GetEhDataReg(I)))
        MBB.addLiveIn(ABI.GetEhDataReg(I));
      TII.storeRegToStackSlot(MBB, MBBI, ABI.GetEhDataReg(I), false,
                              MipsFI->getEhDataRegFI(I), RC, &RegInfo);
    }

    // Emit .cfi_offset directives for eh data registers.
    for (int I = 0; I < 4; ++I) {
      int64_t Offset = MFI->getObjectOffset(MipsFI->getEhDataRegFI(I));
      unsigned Reg = MRI->getDwarfRegNum(ABI.GetEhDataReg(I), true);
      unsigned CFIIndex = MMI.addFrameInst(
          MCCFIInstruction::createOffset(nullptr, Reg, Offset));
      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
          .addCFIIndex(CFIIndex);
    }
  }

  // if framepointer enabled, set it to point to the stack pointer.
  if (hasFP(MF)) {
    // Insert instruction "move $fp, $sp" at this location.
    BuildMI(MBB, MBBI, dl, TII.get(MOVE), FP).addReg(SP).addReg(ZERO)
      .setMIFlag(MachineInstr::FrameSetup);

    // emit ".cfi_def_cfa_register $fp"
    unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
        nullptr, MRI->getDwarfRegNum(FP, true)));
    BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
        .addCFIIndex(CFIIndex);

    if (RegInfo.needsStackRealignment(MF)) {
      // addiu $Reg, $zero, -MaxAlignment
      // andi $sp, $sp, $Reg
      unsigned VR = MF.getRegInfo().createVirtualRegister(RC);
      assert(isInt<16>(MFI->getMaxAlignment()) &&
             "Function's alignment size requirement is not supported.");
      int MaxAlign = - (signed) MFI->getMaxAlignment();

      BuildMI(MBB, MBBI, dl, TII.get(ADDiu), VR).addReg(ZERO) .addImm(MaxAlign);
      BuildMI(MBB, MBBI, dl, TII.get(AND), SP).addReg(SP).addReg(VR);

      if (hasBP(MF)) {
        // move $s7, $sp
        unsigned BP = STI.isABI_N64() ? Mips::S7_64 : Mips::S7;
        BuildMI(MBB, MBBI, dl, TII.get(MOVE), BP)
          .addReg(SP)
          .addReg(ZERO);
      }
    }
  }
}
Ejemplo n.º 29
0
void MIRPrinter::convertStackObjects(yaml::MachineFunction &MF,
                                     const MachineFrameInfo &MFI,
                                     MachineModuleInfo &MMI,
                                     ModuleSlotTracker &MST,
                                     const TargetRegisterInfo *TRI) {
  // Process fixed stack objects.
  unsigned ID = 0;
  for (int I = MFI.getObjectIndexBegin(); I < 0; ++I) {
    if (MFI.isDeadObjectIndex(I))
      continue;

    yaml::FixedMachineStackObject YamlObject;
    YamlObject.ID = ID;
    YamlObject.Type = MFI.isSpillSlotObjectIndex(I)
                          ? yaml::FixedMachineStackObject::SpillSlot
                          : yaml::FixedMachineStackObject::DefaultType;
    YamlObject.Offset = MFI.getObjectOffset(I);
    YamlObject.Size = MFI.getObjectSize(I);
    YamlObject.Alignment = MFI.getObjectAlignment(I);
    YamlObject.IsImmutable = MFI.isImmutableObjectIndex(I);
    YamlObject.IsAliased = MFI.isAliasedObjectIndex(I);
    MF.FixedStackObjects.push_back(YamlObject);
    StackObjectOperandMapping.insert(
        std::make_pair(I, FrameIndexOperand::createFixed(ID++)));
  }

  // Process ordinary stack objects.
  ID = 0;
  for (int I = 0, E = MFI.getObjectIndexEnd(); I < E; ++I) {
    if (MFI.isDeadObjectIndex(I))
      continue;

    yaml::MachineStackObject YamlObject;
    YamlObject.ID = ID;
    if (const auto *Alloca = MFI.getObjectAllocation(I))
      YamlObject.Name.Value =
          Alloca->hasName() ? Alloca->getName() : "<unnamed alloca>";
    YamlObject.Type = MFI.isSpillSlotObjectIndex(I)
                          ? yaml::MachineStackObject::SpillSlot
                          : MFI.isVariableSizedObjectIndex(I)
                                ? yaml::MachineStackObject::VariableSized
                                : yaml::MachineStackObject::DefaultType;
    YamlObject.Offset = MFI.getObjectOffset(I);
    YamlObject.Size = MFI.getObjectSize(I);
    YamlObject.Alignment = MFI.getObjectAlignment(I);

    MF.StackObjects.push_back(YamlObject);
    StackObjectOperandMapping.insert(std::make_pair(
        I, FrameIndexOperand::create(YamlObject.Name.Value, ID++)));
  }

  for (const auto &CSInfo : MFI.getCalleeSavedInfo()) {
    yaml::StringValue Reg;
    printReg(CSInfo.getReg(), Reg, TRI);
    auto StackObjectInfo = StackObjectOperandMapping.find(CSInfo.getFrameIdx());
    assert(StackObjectInfo != StackObjectOperandMapping.end() &&
           "Invalid stack object index");
    const FrameIndexOperand &StackObject = StackObjectInfo->second;
    if (StackObject.IsFixed)
      MF.FixedStackObjects[StackObject.ID].CalleeSavedRegister = Reg;
    else
      MF.StackObjects[StackObject.ID].CalleeSavedRegister = Reg;
  }
  for (unsigned I = 0, E = MFI.getLocalFrameObjectCount(); I < E; ++I) {
    auto LocalObject = MFI.getLocalFrameObjectMap(I);
    auto StackObjectInfo = StackObjectOperandMapping.find(LocalObject.first);
    assert(StackObjectInfo != StackObjectOperandMapping.end() &&
           "Invalid stack object index");
    const FrameIndexOperand &StackObject = StackObjectInfo->second;
    assert(!StackObject.IsFixed && "Expected a locally mapped stack object");
    MF.StackObjects[StackObject.ID].LocalOffset = LocalObject.second;
  }

  // Print the stack object references in the frame information class after
  // converting the stack objects.
  if (MFI.hasStackProtectorIndex()) {
    raw_string_ostream StrOS(MF.FrameInfo.StackProtector.Value);
    MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
        .printStackObjectReference(MFI.getStackProtectorIndex());
  }

  // Print the debug variable information.
  for (MachineModuleInfo::VariableDbgInfo &DebugVar :
       MMI.getVariableDbgInfo()) {
    auto StackObjectInfo = StackObjectOperandMapping.find(DebugVar.Slot);
    assert(StackObjectInfo != StackObjectOperandMapping.end() &&
           "Invalid stack object index");
    const FrameIndexOperand &StackObject = StackObjectInfo->second;
    assert(!StackObject.IsFixed && "Expected a non-fixed stack object");
    auto &Object = MF.StackObjects[StackObject.ID];
    {
      raw_string_ostream StrOS(Object.DebugVar.Value);
      DebugVar.Var->printAsOperand(StrOS, MST);
    }
    {
      raw_string_ostream StrOS(Object.DebugExpr.Value);
      DebugVar.Expr->printAsOperand(StrOS, MST);
    }
    {
      raw_string_ostream StrOS(Object.DebugLoc.Value);
      DebugVar.Loc->printAsOperand(StrOS, MST);
    }
  }
}
Ejemplo n.º 30
0
/// getFrameIndexOffset - Returns the displacement from the frame register to
/// the stack frame of the specified index. This is the default implementation
/// which is likely incorrect for the target.
int TargetRegisterInfo::getFrameIndexOffset(MachineFunction &MF, int FI) const {
  const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  return MFI->getObjectOffset(FI) + MFI->getStackSize() -
    TFI.getOffsetOfLocalArea() + MFI->getOffsetAdjustment();
}