static std::string computeDataLayout(const Triple &TT, StringRef CPU,
                                     const TargetOptions &Options,
                                     bool isLittle) {
  std::string Ret;
  MipsABIInfo ABI = MipsABIInfo::computeTargetABI(TT, CPU, Options.MCOptions);

  // There are both little and big endian mips.
  if (isLittle)
    Ret += "e";
  else
    Ret += "E";

  if (ABI.IsO32())
    Ret += "-m:m";
  else
    Ret += "-m:e";

  // Pointers are 32 bit on some ABIs.
  if (!ABI.IsN64())
    Ret += "-p:32:32";

  // 8 and 16 bit integers only need to have natural alignment, but try to
  // align them to 32 bits. 64 bit integers have natural alignment.
  Ret += "-i8:8:32-i16:16:32-i64:64";

  // 32 bit registers are always available and the stack is at least 64 bit
  // aligned. On N64 64 bit registers are also available and the stack is
  // 128 bit aligned.
  if (ABI.IsN64() || ABI.IsN32())
    Ret += "-n32:64-S128";
  else
    Ret += "-n32-S64";

  return Ret;
}
示例#2
0
void MipsSEFrameLowering::determineCalleeSaves(MachineFunction &MF,
                                               BitVector &SavedRegs,
                                               RegScavenger *RS) const {
  TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS);
  MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
  MipsABIInfo ABI = STI.getABI();
  unsigned FP = ABI.GetFramePtr();
  unsigned BP = ABI.IsN64() ? Mips::S7_64 : Mips::S7;

  // Mark $fp as used if function has dedicated frame pointer.
  if (hasFP(MF))
    setAliasRegs(MF, SavedRegs, FP);
  // Mark $s7 as used if function has dedicated base pointer.
  if (hasBP(MF))
    setAliasRegs(MF, SavedRegs, BP);

  // Create spill slots for eh data registers if function calls eh_return.
  if (MipsFI->callsEhReturn())
    MipsFI->createEhDataRegsFI();

  // Create spill slots for Coprocessor 0 registers if function is an ISR.
  if (MipsFI->isISR())
    MipsFI->createISRRegFI();

  // Expand pseudo instructions which load, store or copy accumulators.
  // Add an emergency spill slot if a pseudo was expanded.
  if (ExpandPseudo(MF).expand()) {
    // The spill slot should be half the size of the accumulator. If target is
    // mips64, it should be 64-bit, otherwise it should be 32-bt.
    const TargetRegisterClass *RC = STI.hasMips64() ?
      &Mips::GPR64RegClass : &Mips::GPR32RegClass;
    int FI = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
                                                  RC->getAlignment(), false);
    RS->addScavengingFrameIndex(FI);
  }

  // Set scavenging frame index if necessary.
  uint64_t MaxSPOffset = MF.getInfo<MipsFunctionInfo>()->getIncomingArgSize() +
    estimateStackSize(MF);

  if (isInt<16>(MaxSPOffset))
    return;

  const TargetRegisterClass *RC =
      ABI.ArePtrs64bit() ? &Mips::GPR64RegClass : &Mips::GPR32RegClass;
  int FI = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
                                                RC->getAlignment(), false);
  RS->addScavengingFrameIndex(FI);
}
示例#3
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);
      }
    }
  }
}