Example #1
0
/// Generate a predicated version of MI (where the condition is given via
/// PredR and Cond) at the point indicated by Where.
void HexagonExpandCondsets::predicateAt(const MachineOperand &DefOp,
                                        MachineInstr &MI,
                                        MachineBasicBlock::iterator Where,
                                        const MachineOperand &PredOp, bool Cond,
                                        std::set<unsigned> &UpdRegs) {
  // The problem with updating live intervals is that we can move one def
  // past another def. In particular, this can happen when moving an A2_tfrt
  // over an A2_tfrf defining the same register. From the point of view of
  // live intervals, these two instructions are two separate definitions,
  // and each one starts another live segment. LiveIntervals's "handleMove"
  // does not allow such moves, so we need to handle it ourselves. To avoid
  // invalidating liveness data while we are using it, the move will be
  // implemented in 4 steps: (1) add a clone of the instruction MI at the
  // target location, (2) update liveness, (3) delete the old instruction,
  // and (4) update liveness again.

  MachineBasicBlock &B = *MI.getParent();
  DebugLoc DL = Where->getDebugLoc();  // "Where" points to an instruction.
  unsigned Opc = MI.getOpcode();
  unsigned PredOpc = HII->getCondOpcode(Opc, !Cond);
  MachineInstrBuilder MB = BuildMI(B, Where, DL, HII->get(PredOpc));
  unsigned Ox = 0, NP = MI.getNumOperands();
  // Skip all defs from MI first.
  while (Ox < NP) {
    MachineOperand &MO = MI.getOperand(Ox);
    if (!MO.isReg() || !MO.isDef())
      break;
    Ox++;
  }
  // Add the new def, then the predicate register, then the rest of the
  // operands.
  MB.addReg(DefOp.getReg(), getRegState(DefOp), DefOp.getSubReg());
  MB.addReg(PredOp.getReg(), PredOp.isUndef() ? RegState::Undef : 0,
            PredOp.getSubReg());
  while (Ox < NP) {
    MachineOperand &MO = MI.getOperand(Ox);
    if (!MO.isReg() || !MO.isImplicit())
      MB.add(MO);
    Ox++;
  }

  MachineFunction &MF = *B.getParent();
  MachineInstr::mmo_iterator I = MI.memoperands_begin();
  unsigned NR = std::distance(I, MI.memoperands_end());
  MachineInstr::mmo_iterator MemRefs = MF.allocateMemRefsArray(NR);
  for (unsigned i = 0; i < NR; ++i)
    MemRefs[i] = *I++;
  MB.setMemRefs(MemRefs, MemRefs+NR);

  MachineInstr *NewI = MB;
  NewI->clearKillInfo();
  LIS->InsertMachineInstrInMaps(*NewI);

  for (auto &Op : NewI->operands())
    if (Op.isReg())
      UpdRegs.insert(Op.getReg());
}
void HexagonEarlyIfConversion::predicateInstr(MachineBasicBlock *ToB,
      MachineBasicBlock::iterator At, MachineInstr *MI,
      unsigned PredR, bool IfTrue) {
  DebugLoc DL;
  if (At != ToB->end())
    DL = At->getDebugLoc();
  else if (!ToB->empty())
    DL = ToB->back().getDebugLoc();

  unsigned Opc = MI->getOpcode();

  if (isPredicableStore(MI)) {
    unsigned COpc = getCondStoreOpcode(Opc, IfTrue);
    assert(COpc);
    MachineInstrBuilder MIB = BuildMI(*ToB, At, DL, HII->get(COpc));
    MachineInstr::mop_iterator MOI = MI->operands_begin();
    if (HII->isPostIncrement(*MI)) {
      MIB.addOperand(*MOI);
      ++MOI;
    }
    MIB.addReg(PredR);
    for (const MachineOperand &MO : make_range(MOI, MI->operands_end()))
      MIB.addOperand(MO);

    // Set memory references.
    MachineInstr::mmo_iterator MMOBegin = MI->memoperands_begin();
    MachineInstr::mmo_iterator MMOEnd = MI->memoperands_end();
    MIB.setMemRefs(MMOBegin, MMOEnd);

    MI->eraseFromParent();
    return;
  }

  if (Opc == Hexagon::J2_jump) {
    MachineBasicBlock *TB = MI->getOperand(0).getMBB();
    const MCInstrDesc &D = HII->get(IfTrue ? Hexagon::J2_jumpt
                                           : Hexagon::J2_jumpf);
    BuildMI(*ToB, At, DL, D)
      .addReg(PredR)
      .addMBB(TB);
    MI->eraseFromParent();
    return;
  }

  // Print the offending instruction unconditionally as we are about to
  // abort.
  dbgs() << *MI;
  llvm_unreachable("Unexpected instruction");
}
Example #3
0
void ARMInstrInfo::expandLoadStackGuard(MachineBasicBlock::iterator MI) const {
  MachineFunction &MF = *MI->getParent()->getParent();
  const ARMSubtarget &Subtarget = MF.getSubtarget<ARMSubtarget>();
  const TargetMachine &TM = MF.getTarget();

  if (!Subtarget.useMovt(MF)) {
    if (TM.isPositionIndependent())
      expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_pcrel, ARM::LDRi12);
    else
      expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_abs, ARM::LDRi12);
    return;
  }

  if (!TM.isPositionIndependent()) {
    expandLoadStackGuardBase(MI, ARM::MOVi32imm, ARM::LDRi12);
    return;
  }

  const GlobalValue *GV =
      cast<GlobalValue>((*MI->memoperands_begin())->getValue());

  if (!Subtarget.isGVIndirectSymbol(GV)) {
    expandLoadStackGuardBase(MI, ARM::MOV_ga_pcrel, ARM::LDRi12);
    return;
  }

  MachineBasicBlock &MBB = *MI->getParent();
  DebugLoc DL = MI->getDebugLoc();
  unsigned Reg = MI->getOperand(0).getReg();
  MachineInstrBuilder MIB;

  MIB = BuildMI(MBB, MI, DL, get(ARM::MOV_ga_pcrel_ldr), Reg)
            .addGlobalAddress(GV, 0, ARMII::MO_NONLAZY);
  auto Flags = MachineMemOperand::MOLoad |
               MachineMemOperand::MODereferenceable |
               MachineMemOperand::MOInvariant;
  MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
      MachinePointerInfo::getGOT(*MBB.getParent()), Flags, 4, 4);
  MIB.addMemOperand(MMO);
  MIB = BuildMI(MBB, MI, DL, get(ARM::LDRi12), Reg);
  MIB.addReg(Reg, RegState::Kill).addImm(0);
  MIB.setMemRefs(MI->memoperands_begin(), MI->memoperands_end());
  AddDefaultPred(MIB);
}
Example #4
0
MachineInstrBuilder
MipsInstrInfo::genInstrWithNewOpc(unsigned NewOpc,
                                  MachineBasicBlock::iterator I) const {
  MachineInstrBuilder MIB;

  // Certain branches have two forms: e.g beq $1, $zero, dst vs beqz $1, dest
  // Pick the zero form of the branch for readable assembly and for greater
  // branch distance in non-microMIPS mode.
  // FIXME: Certain atomic sequences on mips64 generate 32bit references to
  // Mips::ZERO, which is incorrect. This test should be updated to use
  // Subtarget.getABI().GetZeroReg() when those atomic sequences and others
  // are fixed.
  bool BranchWithZeroOperand =
      (I->isBranch() && !I->isPseudo() && I->getOperand(1).isReg() &&
       (I->getOperand(1).getReg() == Mips::ZERO ||
        I->getOperand(1).getReg() == Mips::ZERO_64));

  if (BranchWithZeroOperand) {
    switch (NewOpc) {
    case Mips::BEQC:
      NewOpc = Mips::BEQZC;
      break;
    case Mips::BNEC:
      NewOpc = Mips::BNEZC;
      break;
    case Mips::BGEC:
      NewOpc = Mips::BGEZC;
      break;
    case Mips::BLTC:
      NewOpc = Mips::BLTZC;
      break;
    }
  }

  MIB = BuildMI(*I->getParent(), I, I->getDebugLoc(), get(NewOpc));

  // For MIPSR6 JI*C requires an immediate 0 as an operand, JIALC(64) an
  // immediate 0 as an operand and requires the removal of it's %RA<imp-def>
  // implicit operand as copying the implicit operations of the instructio we're
  // looking at will give us the correct flags.
  if (NewOpc == Mips::JIC || NewOpc == Mips::JIALC || NewOpc == Mips::JIC64 ||
      NewOpc == Mips::JIALC64) {

    if (NewOpc == Mips::JIALC || NewOpc == Mips::JIALC64)
      MIB->RemoveOperand(0);

    for (unsigned J = 0, E = I->getDesc().getNumOperands(); J < E; ++J) {
      MIB.addOperand(I->getOperand(J));
    }

    MIB.addImm(0);

 } else if (BranchWithZeroOperand) {
    // For MIPSR6 and microMIPS branches with an explicit zero operand, copy
    // everything after the zero.
     MIB.addOperand(I->getOperand(0));

    for (unsigned J = 2, E = I->getDesc().getNumOperands(); J < E; ++J) {
      MIB.addOperand(I->getOperand(J));
    }
  } else {
    // All other cases copy all other operands.
    for (unsigned J = 0, E = I->getDesc().getNumOperands(); J < E; ++J) {
      MIB.addOperand(I->getOperand(J));
    }
  }

  MIB.copyImplicitOps(*I);

  MIB.setMemRefs(I->memoperands_begin(), I->memoperands_end());
  return MIB;
}
Example #5
0
MachineInstrBuilder
MipsInstrInfo::genInstrWithNewOpc(unsigned NewOpc,
                                  MachineBasicBlock::iterator I) const {
  MachineInstrBuilder MIB;

  // Certain branches have two forms: e.g beq $1, $zero, dest vs beqz $1, dest
  // Pick the zero form of the branch for readable assembly and for greater
  // branch distance in non-microMIPS mode.
  // Additional MIPSR6 does not permit the use of register $zero for compact
  // branches.
  // FIXME: Certain atomic sequences on mips64 generate 32bit references to
  // Mips::ZERO, which is incorrect. This test should be updated to use
  // Subtarget.getABI().GetZeroReg() when those atomic sequences and others
  // are fixed.
  int ZeroOperandPosition = -1;
  bool BranchWithZeroOperand = false;
  if (I->isBranch() && !I->isPseudo()) {
    auto TRI = I->getParent()->getParent()->getSubtarget().getRegisterInfo();
    ZeroOperandPosition = I->findRegisterUseOperandIdx(Mips::ZERO, false, TRI);
    BranchWithZeroOperand = ZeroOperandPosition != -1;
  }

  if (BranchWithZeroOperand) {
    switch (NewOpc) {
    case Mips::BEQC:
      NewOpc = Mips::BEQZC;
      break;
    case Mips::BNEC:
      NewOpc = Mips::BNEZC;
      break;
    case Mips::BGEC:
      NewOpc = Mips::BGEZC;
      break;
    case Mips::BLTC:
      NewOpc = Mips::BLTZC;
      break;
    case Mips::BEQC64:
      NewOpc = Mips::BEQZC64;
      break;
    case Mips::BNEC64:
      NewOpc = Mips::BNEZC64;
      break;
    }
  }

  MIB = BuildMI(*I->getParent(), I, I->getDebugLoc(), get(NewOpc));

  // For MIPSR6 JI*C requires an immediate 0 as an operand, JIALC(64) an
  // immediate 0 as an operand and requires the removal of it's %RA<imp-def>
  // implicit operand as copying the implicit operations of the instructio we're
  // looking at will give us the correct flags.
  if (NewOpc == Mips::JIC || NewOpc == Mips::JIALC || NewOpc == Mips::JIC64 ||
      NewOpc == Mips::JIALC64) {

    if (NewOpc == Mips::JIALC || NewOpc == Mips::JIALC64)
      MIB->RemoveOperand(0);

    for (unsigned J = 0, E = I->getDesc().getNumOperands(); J < E; ++J) {
      MIB.add(I->getOperand(J));
    }

    MIB.addImm(0);

  } else {
    for (unsigned J = 0, E = I->getDesc().getNumOperands(); J < E; ++J) {
      if (BranchWithZeroOperand && (unsigned)ZeroOperandPosition == J)
        continue;

      MIB.add(I->getOperand(J));
    }
  }

  MIB.copyImplicitOps(*I);

  MIB.setMemRefs(I->memoperands_begin(), I->memoperands_end());
  return MIB;
}
Example #6
0
/// EmitMachineNode - Generate machine code for a target-specific node and
/// needed dependencies.
///
void InstrEmitter::
EmitMachineNode(SDNode *Node, bool IsClone, bool IsCloned,
                DenseMap<SDValue, unsigned> &VRBaseMap) {
  unsigned Opc = Node->getMachineOpcode();

  // Handle subreg insert/extract specially
  if (Opc == TargetOpcode::EXTRACT_SUBREG ||
      Opc == TargetOpcode::INSERT_SUBREG ||
      Opc == TargetOpcode::SUBREG_TO_REG) {
    EmitSubregNode(Node, VRBaseMap, IsClone, IsCloned);
    return;
  }

  // Handle COPY_TO_REGCLASS specially.
  if (Opc == TargetOpcode::COPY_TO_REGCLASS) {
    EmitCopyToRegClassNode(Node, VRBaseMap);
    return;
  }

  // Handle REG_SEQUENCE specially.
  if (Opc == TargetOpcode::REG_SEQUENCE) {
    EmitRegSequence(Node, VRBaseMap, IsClone, IsCloned);
    return;
  }

  if (Opc == TargetOpcode::IMPLICIT_DEF)
    // We want a unique VR for each IMPLICIT_DEF use.
    return;

  const MCInstrDesc &II = TII->get(Opc);
  unsigned NumResults = CountResults(Node);
  unsigned NumDefs = II.getNumDefs();
  const MCPhysReg *ScratchRegs = nullptr;

  // Handle STACKMAP and PATCHPOINT specially and then use the generic code.
  if (Opc == TargetOpcode::STACKMAP || Opc == TargetOpcode::PATCHPOINT) {
    // Stackmaps do not have arguments and do not preserve their calling
    // convention. However, to simplify runtime support, they clobber the same
    // scratch registers as AnyRegCC.
    unsigned CC = CallingConv::AnyReg;
    if (Opc == TargetOpcode::PATCHPOINT) {
      CC = Node->getConstantOperandVal(PatchPointOpers::CCPos);
      NumDefs = NumResults;
    }
    ScratchRegs = TLI->getScratchRegisters((CallingConv::ID) CC);
  }

  unsigned NumImpUses = 0;
  unsigned NodeOperands =
    countOperands(Node, II.getNumOperands() - NumDefs, NumImpUses);
  bool HasPhysRegOuts = NumResults > NumDefs && II.getImplicitDefs()!=nullptr;
#ifndef NDEBUG
  unsigned NumMIOperands = NodeOperands + NumResults;
  if (II.isVariadic())
    assert(NumMIOperands >= II.getNumOperands() &&
           "Too few operands for a variadic node!");
  else
    assert(NumMIOperands >= II.getNumOperands() &&
           NumMIOperands <= II.getNumOperands() + II.getNumImplicitDefs() +
                            NumImpUses &&
           "#operands for dag node doesn't match .td file!");
#endif

  // Create the new machine instruction.
  MachineInstrBuilder MIB = BuildMI(*MF, Node->getDebugLoc(), II);

  // Add result register values for things that are defined by this
  // instruction.
  if (NumResults) {
    CreateVirtualRegisters(Node, MIB, II, IsClone, IsCloned, VRBaseMap);

    // Transfer any IR flags from the SDNode to the MachineInstr
    MachineInstr *MI = MIB.getInstr();
    const SDNodeFlags Flags = Node->getFlags();
    if (Flags.hasNoSignedZeros())
      MI->setFlag(MachineInstr::MIFlag::FmNsz);

    if (Flags.hasAllowReciprocal())
      MI->setFlag(MachineInstr::MIFlag::FmArcp);

    if (Flags.hasNoNaNs())
      MI->setFlag(MachineInstr::MIFlag::FmNoNans);

    if (Flags.hasNoInfs())
      MI->setFlag(MachineInstr::MIFlag::FmNoInfs);

    if (Flags.hasAllowContract())
      MI->setFlag(MachineInstr::MIFlag::FmContract);

    if (Flags.hasApproximateFuncs())
      MI->setFlag(MachineInstr::MIFlag::FmAfn);

    if (Flags.hasAllowReassociation())
      MI->setFlag(MachineInstr::MIFlag::FmReassoc);
  }

  // Emit all of the actual operands of this instruction, adding them to the
  // instruction as appropriate.
  bool HasOptPRefs = NumDefs > NumResults;
  assert((!HasOptPRefs || !HasPhysRegOuts) &&
         "Unable to cope with optional defs and phys regs defs!");
  unsigned NumSkip = HasOptPRefs ? NumDefs - NumResults : 0;
  for (unsigned i = NumSkip; i != NodeOperands; ++i)
    AddOperand(MIB, Node->getOperand(i), i-NumSkip+NumDefs, &II,
               VRBaseMap, /*IsDebug=*/false, IsClone, IsCloned);

  // Add scratch registers as implicit def and early clobber
  if (ScratchRegs)
    for (unsigned i = 0; ScratchRegs[i]; ++i)
      MIB.addReg(ScratchRegs[i], RegState::ImplicitDefine |
                                 RegState::EarlyClobber);

  // Transfer all of the memory reference descriptions of this instruction.
  MIB.setMemRefs(cast<MachineSDNode>(Node)->memoperands_begin(),
                 cast<MachineSDNode>(Node)->memoperands_end());

  // Insert the instruction into position in the block. This needs to
  // happen before any custom inserter hook is called so that the
  // hook knows where in the block to insert the replacement code.
  MBB->insert(InsertPos, MIB);

  // The MachineInstr may also define physregs instead of virtregs.  These
  // physreg values can reach other instructions in different ways:
  //
  // 1. When there is a use of a Node value beyond the explicitly defined
  //    virtual registers, we emit a CopyFromReg for one of the implicitly
  //    defined physregs.  This only happens when HasPhysRegOuts is true.
  //
  // 2. A CopyFromReg reading a physreg may be glued to this instruction.
  //
  // 3. A glued instruction may implicitly use a physreg.
  //
  // 4. A glued instruction may use a RegisterSDNode operand.
  //
  // Collect all the used physreg defs, and make sure that any unused physreg
  // defs are marked as dead.
  SmallVector<unsigned, 8> UsedRegs;

  // Additional results must be physical register defs.
  if (HasPhysRegOuts) {
    for (unsigned i = NumDefs; i < NumResults; ++i) {
      unsigned Reg = II.getImplicitDefs()[i - NumDefs];
      if (!Node->hasAnyUseOfValue(i))
        continue;
      // This implicitly defined physreg has a use.
      UsedRegs.push_back(Reg);
      EmitCopyFromReg(Node, i, IsClone, IsCloned, Reg, VRBaseMap);
    }
  }

  // Scan the glue chain for any used physregs.
  if (Node->getValueType(Node->getNumValues()-1) == MVT::Glue) {
    for (SDNode *F = Node->getGluedUser(); F; F = F->getGluedUser()) {
      if (F->getOpcode() == ISD::CopyFromReg) {
        UsedRegs.push_back(cast<RegisterSDNode>(F->getOperand(1))->getReg());
        continue;
      } else if (F->getOpcode() == ISD::CopyToReg) {
        // Skip CopyToReg nodes that are internal to the glue chain.
        continue;
      }
      // Collect declared implicit uses.
      const MCInstrDesc &MCID = TII->get(F->getMachineOpcode());
      UsedRegs.append(MCID.getImplicitUses(),
                      MCID.getImplicitUses() + MCID.getNumImplicitUses());
      // In addition to declared implicit uses, we must also check for
      // direct RegisterSDNode operands.
      for (unsigned i = 0, e = F->getNumOperands(); i != e; ++i)
        if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(F->getOperand(i))) {
          unsigned Reg = R->getReg();
          if (TargetRegisterInfo::isPhysicalRegister(Reg))
            UsedRegs.push_back(Reg);
        }
    }
  }

  // Finally mark unused registers as dead.
  if (!UsedRegs.empty() || II.getImplicitDefs())
    MIB->setPhysRegsDeadExcept(UsedRegs, *TRI);

  // Run post-isel target hook to adjust this instruction if needed.
  if (II.hasPostISelHook())
    TLI->AdjustInstrPostInstrSelection(*MIB, Node);
}
Example #7
0
bool
Thumb2SizeReduce::ReduceLoadStore(MachineBasicBlock &MBB, MachineInstr *MI,
                                  const ReduceEntry &Entry) {
  if (ReduceLimitLdSt != -1 && ((int)NumLdSts >= ReduceLimitLdSt))
    return false;

  unsigned Scale = 1;
  bool HasImmOffset = false;
  bool HasShift = false;
  bool HasOffReg = true;
  bool isLdStMul = false;
  unsigned Opc = Entry.NarrowOpc1;
  unsigned OpNum = 3; // First 'rest' of operands.
  uint8_t  ImmLimit = Entry.Imm1Limit;

  switch (Entry.WideOpc) {
  default:
    llvm_unreachable("Unexpected Thumb2 load / store opcode!");
  case ARM::t2LDRi12:
  case ARM::t2STRi12:
    if (MI->getOperand(1).getReg() == ARM::SP) {
      Opc = Entry.NarrowOpc2;
      ImmLimit = Entry.Imm2Limit;
      HasOffReg = false;
    }

    Scale = 4;
    HasImmOffset = true;
    HasOffReg = false;
    break;
  case ARM::t2LDRBi12:
  case ARM::t2STRBi12:
    HasImmOffset = true;
    HasOffReg = false;
    break;
  case ARM::t2LDRHi12:
  case ARM::t2STRHi12:
    Scale = 2;
    HasImmOffset = true;
    HasOffReg = false;
    break;
  case ARM::t2LDRs:
  case ARM::t2LDRBs:
  case ARM::t2LDRHs:
  case ARM::t2LDRSBs:
  case ARM::t2LDRSHs:
  case ARM::t2STRs:
  case ARM::t2STRBs:
  case ARM::t2STRHs:
    HasShift = true;
    OpNum = 4;
    break;
  case ARM::t2LDMIA:
  case ARM::t2LDMDB: {
    unsigned BaseReg = MI->getOperand(0).getReg();
    if (!isARMLowRegister(BaseReg) || Entry.WideOpc != ARM::t2LDMIA)
      return false;

    // For the non-writeback version (this one), the base register must be
    // one of the registers being loaded.
    bool isOK = false;
    for (unsigned i = 4; i < MI->getNumOperands(); ++i) {
      if (MI->getOperand(i).getReg() == BaseReg) {
        isOK = true;
        break;
      }
    }

    if (!isOK)
      return false;

    OpNum = 0;
    isLdStMul = true;
    break;
  }
  case ARM::t2LDMIA_RET: {
    unsigned BaseReg = MI->getOperand(1).getReg();
    if (BaseReg != ARM::SP)
      return false;
    Opc = Entry.NarrowOpc2; // tPOP_RET
    OpNum = 2;
    isLdStMul = true;
    break;
  }
  case ARM::t2LDMIA_UPD:
  case ARM::t2LDMDB_UPD:
  case ARM::t2STMIA_UPD:
  case ARM::t2STMDB_UPD: {
    OpNum = 0;

    unsigned BaseReg = MI->getOperand(1).getReg();
    if (BaseReg == ARM::SP &&
        (Entry.WideOpc == ARM::t2LDMIA_UPD ||
         Entry.WideOpc == ARM::t2STMDB_UPD)) {
      Opc = Entry.NarrowOpc2; // tPOP or tPUSH
      OpNum = 2;
    } else if (!isARMLowRegister(BaseReg) ||
               (Entry.WideOpc != ARM::t2LDMIA_UPD &&
                Entry.WideOpc != ARM::t2STMIA_UPD)) {
      return false;
    }

    isLdStMul = true;
    break;
  }
  }

  unsigned OffsetReg = 0;
  bool OffsetKill = false;
  if (HasShift) {
    OffsetReg  = MI->getOperand(2).getReg();
    OffsetKill = MI->getOperand(2).isKill();

    if (MI->getOperand(3).getImm())
      // Thumb1 addressing mode doesn't support shift.
      return false;
  }

  unsigned OffsetImm = 0;
  if (HasImmOffset) {
    OffsetImm = MI->getOperand(2).getImm();
    unsigned MaxOffset = ((1 << ImmLimit) - 1) * Scale;

    if ((OffsetImm & (Scale - 1)) || OffsetImm > MaxOffset)
      // Make sure the immediate field fits.
      return false;
  }

  // Add the 16-bit load / store instruction.
  DebugLoc dl = MI->getDebugLoc();
  MachineInstrBuilder MIB = BuildMI(MBB, MI, dl, TII->get(Opc));
  if (!isLdStMul) {
    MIB.addOperand(MI->getOperand(0));
    MIB.addOperand(MI->getOperand(1));

    if (HasImmOffset)
      MIB.addImm(OffsetImm / Scale);

    assert((!HasShift || OffsetReg) && "Invalid so_reg load / store address!");

    if (HasOffReg)
      MIB.addReg(OffsetReg, getKillRegState(OffsetKill));
  }

  // Transfer the rest of operands.
  for (unsigned e = MI->getNumOperands(); OpNum != e; ++OpNum)
    MIB.addOperand(MI->getOperand(OpNum));

  // Transfer memoperands.
  MIB->setMemRefs(MI->memoperands_begin(), MI->memoperands_end());

  // Transfer MI flags.
  MIB.setMIFlags(MI->getFlags());

  DEBUG(errs() << "Converted 32-bit: " << *MI << "       to 16-bit: " << *MIB);

  MBB.erase_instr(MI);
  ++NumLdSts;
  return true;
}
Example #8
0
/// EmitMachineNode - Generate machine code for a target-specific node and
/// needed dependencies.
///
void InstrEmitter::
EmitMachineNode(SDNode *Node, bool IsClone, bool IsCloned,
                DenseMap<SDValue, unsigned> &VRBaseMap) {
  unsigned Opc = Node->getMachineOpcode();

  // Handle subreg insert/extract specially
  if (Opc == TargetOpcode::EXTRACT_SUBREG ||
      Opc == TargetOpcode::INSERT_SUBREG ||
      Opc == TargetOpcode::SUBREG_TO_REG) {
    EmitSubregNode(Node, VRBaseMap, IsClone, IsCloned);
    return;
  }

  // Handle COPY_TO_REGCLASS specially.
  if (Opc == TargetOpcode::COPY_TO_REGCLASS) {
    EmitCopyToRegClassNode(Node, VRBaseMap);
    return;
  }

  // Handle REG_SEQUENCE specially.
  if (Opc == TargetOpcode::REG_SEQUENCE) {
    EmitRegSequence(Node, VRBaseMap, IsClone, IsCloned);
    return;
  }

  if (Opc == TargetOpcode::IMPLICIT_DEF)
    // We want a unique VR for each IMPLICIT_DEF use.
    return;

  const MCInstrDesc &II = TII->get(Opc);
  unsigned NumResults = CountResults(Node);
  unsigned NumImpUses = 0;
  unsigned NodeOperands =
    countOperands(Node, II.getNumOperands() - II.getNumDefs(), NumImpUses);
  bool HasPhysRegOuts = NumResults > II.getNumDefs() && II.getImplicitDefs()!=0;
#ifndef NDEBUG
  unsigned NumMIOperands = NodeOperands + NumResults;
  if (II.isVariadic())
    assert(NumMIOperands >= II.getNumOperands() &&
           "Too few operands for a variadic node!");
  else
    assert(NumMIOperands >= II.getNumOperands() &&
           NumMIOperands <= II.getNumOperands() + II.getNumImplicitDefs() +
                            NumImpUses &&
           "#operands for dag node doesn't match .td file!");
#endif

  // Create the new machine instruction.
  MachineInstrBuilder MIB = BuildMI(*MF, Node->getDebugLoc(), II);

  // Add result register values for things that are defined by this
  // instruction.
  if (NumResults)
    CreateVirtualRegisters(Node, MIB, II, IsClone, IsCloned, VRBaseMap);

  // Emit all of the actual operands of this instruction, adding them to the
  // instruction as appropriate.
  bool HasOptPRefs = II.getNumDefs() > NumResults;
  assert((!HasOptPRefs || !HasPhysRegOuts) &&
         "Unable to cope with optional defs and phys regs defs!");
  unsigned NumSkip = HasOptPRefs ? II.getNumDefs() - NumResults : 0;
  for (unsigned i = NumSkip; i != NodeOperands; ++i)
    AddOperand(MIB, Node->getOperand(i), i-NumSkip+II.getNumDefs(), &II,
               VRBaseMap, /*IsDebug=*/false, IsClone, IsCloned);

  // Transfer all of the memory reference descriptions of this instruction.
  MIB.setMemRefs(cast<MachineSDNode>(Node)->memoperands_begin(),
                 cast<MachineSDNode>(Node)->memoperands_end());

  // Insert the instruction into position in the block. This needs to
  // happen before any custom inserter hook is called so that the
  // hook knows where in the block to insert the replacement code.
  MBB->insert(InsertPos, MIB);

  // The MachineInstr may also define physregs instead of virtregs.  These
  // physreg values can reach other instructions in different ways:
  //
  // 1. When there is a use of a Node value beyond the explicitly defined
  //    virtual registers, we emit a CopyFromReg for one of the implicitly
  //    defined physregs.  This only happens when HasPhysRegOuts is true.
  //
  // 2. A CopyFromReg reading a physreg may be glued to this instruction.
  //
  // 3. A glued instruction may implicitly use a physreg.
  //
  // 4. A glued instruction may use a RegisterSDNode operand.
  //
  // Collect all the used physreg defs, and make sure that any unused physreg
  // defs are marked as dead.
  SmallVector<unsigned, 8> UsedRegs;

  // Additional results must be physical register defs.
  if (HasPhysRegOuts) {
    for (unsigned i = II.getNumDefs(); i < NumResults; ++i) {
      unsigned Reg = II.getImplicitDefs()[i - II.getNumDefs()];
      if (!Node->hasAnyUseOfValue(i))
        continue;
      // This implicitly defined physreg has a use.
      UsedRegs.push_back(Reg);
      EmitCopyFromReg(Node, i, IsClone, IsCloned, Reg, VRBaseMap);
    }
  }

  // Scan the glue chain for any used physregs.
  if (Node->getValueType(Node->getNumValues()-1) == MVT::Glue) {
    for (SDNode *F = Node->getGluedUser(); F; F = F->getGluedUser()) {
      if (F->getOpcode() == ISD::CopyFromReg) {
        UsedRegs.push_back(cast<RegisterSDNode>(F->getOperand(1))->getReg());
        continue;
      } else if (F->getOpcode() == ISD::CopyToReg) {
        // Skip CopyToReg nodes that are internal to the glue chain.
        continue;
      }
      // Collect declared implicit uses.
      const MCInstrDesc &MCID = TII->get(F->getMachineOpcode());
      UsedRegs.append(MCID.getImplicitUses(),
                      MCID.getImplicitUses() + MCID.getNumImplicitUses());
      // In addition to declared implicit uses, we must also check for
      // direct RegisterSDNode operands.
      for (unsigned i = 0, e = F->getNumOperands(); i != e; ++i)
        if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(F->getOperand(i))) {
          unsigned Reg = R->getReg();
          if (TargetRegisterInfo::isPhysicalRegister(Reg))
            UsedRegs.push_back(Reg);
        }
    }
  }

  // Finally mark unused registers as dead.
  if (!UsedRegs.empty() || II.getImplicitDefs())
    MIB->setPhysRegsDeadExcept(UsedRegs, *TRI);

  // Run post-isel target hook to adjust this instruction if needed.
#ifdef NDEBUG
  if (II.hasPostISelHook())
#endif
    TLI->AdjustInstrPostInstrSelection(MIB, Node);
}
Example #9
0
bool
Thumb2SizeReduce::ReduceLoadStore(MachineBasicBlock &MBB, MachineInstr *MI,
                                  const ReduceEntry &Entry) {
  if (ReduceLimitLdSt != -1 && ((int)NumLdSts >= ReduceLimitLdSt))
    return false;

  unsigned Scale = 1;
  bool HasImmOffset = false;
  bool HasShift = false;
  bool HasOffReg = true;
  bool isLdStMul = false;
  unsigned Opc = Entry.NarrowOpc1;
  unsigned OpNum = 3; // First 'rest' of operands.
  uint8_t  ImmLimit = Entry.Imm1Limit;

  switch (Entry.WideOpc) {
  default:
    llvm_unreachable("Unexpected Thumb2 load / store opcode!");
  case ARM::t2LDRi12:
  case ARM::t2STRi12:
    if (MI->getOperand(1).getReg() == ARM::SP) {
      Opc = Entry.NarrowOpc2;
      ImmLimit = Entry.Imm2Limit;
    }

    Scale = 4;
    HasImmOffset = true;
    HasOffReg = false;
    break;
  case ARM::t2LDRBi12:
  case ARM::t2STRBi12:
    HasImmOffset = true;
    HasOffReg = false;
    break;
  case ARM::t2LDRHi12:
  case ARM::t2STRHi12:
    Scale = 2;
    HasImmOffset = true;
    HasOffReg = false;
    break;
  case ARM::t2LDRs:
  case ARM::t2LDRBs:
  case ARM::t2LDRHs:
  case ARM::t2LDRSBs:
  case ARM::t2LDRSHs:
  case ARM::t2STRs:
  case ARM::t2STRBs:
  case ARM::t2STRHs:
    HasShift = true;
    OpNum = 4;
    break;
  case ARM::t2LDR_POST:
  case ARM::t2STR_POST: {
    if (!MBB.getParent()->getFunction().optForMinSize())
      return false;

    if (!MI->hasOneMemOperand() ||
        (*MI->memoperands_begin())->getAlignment() < 4)
      return false;

    // We're creating a completely different type of load/store - LDM from LDR.
    // For this reason we can't reuse the logic at the end of this function; we
    // have to implement the MI building here.
    bool IsStore = Entry.WideOpc == ARM::t2STR_POST;
    unsigned Rt = MI->getOperand(IsStore ? 1 : 0).getReg();
    unsigned Rn = MI->getOperand(IsStore ? 0 : 1).getReg();
    unsigned Offset = MI->getOperand(3).getImm();
    unsigned PredImm = MI->getOperand(4).getImm();
    unsigned PredReg = MI->getOperand(5).getReg();
    assert(isARMLowRegister(Rt));
    assert(isARMLowRegister(Rn));

    if (Offset != 4)
      return false;

    // Add the 16-bit load / store instruction.
    DebugLoc dl = MI->getDebugLoc();
    auto MIB = BuildMI(MBB, MI, dl, TII->get(Entry.NarrowOpc1))
                   .addReg(Rn, RegState::Define)
                   .addReg(Rn)
                   .addImm(PredImm)
                   .addReg(PredReg)
                   .addReg(Rt, IsStore ? 0 : RegState::Define);

    // Transfer memoperands.
    MIB.setMemRefs(MI->memoperands());

    // Transfer MI flags.
    MIB.setMIFlags(MI->getFlags());

    // Kill the old instruction.
    MI->eraseFromBundle();
    ++NumLdSts;
    return true;
  }
  case ARM::t2LDMIA: {
    unsigned BaseReg = MI->getOperand(0).getReg();
    assert(isARMLowRegister(BaseReg));

    // For the non-writeback version (this one), the base register must be
    // one of the registers being loaded.
    bool isOK = false;
    for (unsigned i = 3; i < MI->getNumOperands(); ++i) {
      if (MI->getOperand(i).getReg() == BaseReg) {
        isOK = true;
        break;
      }
    }

    if (!isOK)
      return false;

    OpNum = 0;
    isLdStMul = true;
    break;
  }
  case ARM::t2STMIA:
    // If the base register is killed, we don't care what its value is after the
    // instruction, so we can use an updating STMIA.
    if (!MI->getOperand(0).isKill())
      return false;

    break;
  case ARM::t2LDMIA_RET: {
    unsigned BaseReg = MI->getOperand(1).getReg();
    if (BaseReg != ARM::SP)
      return false;
    Opc = Entry.NarrowOpc2; // tPOP_RET
    OpNum = 2;
    isLdStMul = true;
    break;
  }
  case ARM::t2LDMIA_UPD:
  case ARM::t2STMIA_UPD:
  case ARM::t2STMDB_UPD: {
    OpNum = 0;

    unsigned BaseReg = MI->getOperand(1).getReg();
    if (BaseReg == ARM::SP &&
        (Entry.WideOpc == ARM::t2LDMIA_UPD ||
         Entry.WideOpc == ARM::t2STMDB_UPD)) {
      Opc = Entry.NarrowOpc2; // tPOP or tPUSH
      OpNum = 2;
    } else if (!isARMLowRegister(BaseReg) ||
               (Entry.WideOpc != ARM::t2LDMIA_UPD &&
                Entry.WideOpc != ARM::t2STMIA_UPD)) {
      return false;
    }

    isLdStMul = true;
    break;
  }
  }

  unsigned OffsetReg = 0;
  bool OffsetKill = false;
  bool OffsetInternal = false;
  if (HasShift) {
    OffsetReg  = MI->getOperand(2).getReg();
    OffsetKill = MI->getOperand(2).isKill();
    OffsetInternal = MI->getOperand(2).isInternalRead();

    if (MI->getOperand(3).getImm())
      // Thumb1 addressing mode doesn't support shift.
      return false;
  }

  unsigned OffsetImm = 0;
  if (HasImmOffset) {
    OffsetImm = MI->getOperand(2).getImm();
    unsigned MaxOffset = ((1 << ImmLimit) - 1) * Scale;

    if ((OffsetImm & (Scale - 1)) || OffsetImm > MaxOffset)
      // Make sure the immediate field fits.
      return false;
  }

  // Add the 16-bit load / store instruction.
  DebugLoc dl = MI->getDebugLoc();
  MachineInstrBuilder MIB = BuildMI(MBB, MI, dl, TII->get(Opc));

  // tSTMIA_UPD takes a defining register operand. We've already checked that
  // the register is killed, so mark it as dead here.
  if (Entry.WideOpc == ARM::t2STMIA)
    MIB.addReg(MI->getOperand(0).getReg(), RegState::Define | RegState::Dead);

  if (!isLdStMul) {
    MIB.add(MI->getOperand(0));
    MIB.add(MI->getOperand(1));

    if (HasImmOffset)
      MIB.addImm(OffsetImm / Scale);

    assert((!HasShift || OffsetReg) && "Invalid so_reg load / store address!");

    if (HasOffReg)
      MIB.addReg(OffsetReg, getKillRegState(OffsetKill) |
                            getInternalReadRegState(OffsetInternal));
  }

  // Transfer the rest of operands.
  for (unsigned e = MI->getNumOperands(); OpNum != e; ++OpNum)
    MIB.add(MI->getOperand(OpNum));

  // Transfer memoperands.
  MIB.setMemRefs(MI->memoperands());

  // Transfer MI flags.
  MIB.setMIFlags(MI->getFlags());

  LLVM_DEBUG(errs() << "Converted 32-bit: " << *MI
                    << "       to 16-bit: " << *MIB);

  MBB.erase_instr(MI);
  ++NumLdSts;
  return true;
}
Example #10
0
// Convert callee-save register save/restore instruction to do stack pointer
// decrement/increment to allocate/deallocate the callee-save stack area by
// converting store/load to use pre/post increment version.
static MachineBasicBlock::iterator convertCalleeSaveRestoreToSPPrePostIncDec(
    MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
    const DebugLoc &DL, const TargetInstrInfo *TII, int CSStackSizeInc) {
  unsigned NewOpc;
  bool NewIsUnscaled = false;
  switch (MBBI->getOpcode()) {
  default:
    llvm_unreachable("Unexpected callee-save save/restore opcode!");
  case AArch64::STPXi:
    NewOpc = AArch64::STPXpre;
    break;
  case AArch64::STPDi:
    NewOpc = AArch64::STPDpre;
    break;
  case AArch64::STRXui:
    NewOpc = AArch64::STRXpre;
    NewIsUnscaled = true;
    break;
  case AArch64::STRDui:
    NewOpc = AArch64::STRDpre;
    NewIsUnscaled = true;
    break;
  case AArch64::LDPXi:
    NewOpc = AArch64::LDPXpost;
    break;
  case AArch64::LDPDi:
    NewOpc = AArch64::LDPDpost;
    break;
  case AArch64::LDRXui:
    NewOpc = AArch64::LDRXpost;
    NewIsUnscaled = true;
    break;
  case AArch64::LDRDui:
    NewOpc = AArch64::LDRDpost;
    NewIsUnscaled = true;
    break;
  }

  MachineInstrBuilder MIB = BuildMI(MBB, MBBI, DL, TII->get(NewOpc));
  MIB.addReg(AArch64::SP, RegState::Define);

  // Copy all operands other than the immediate offset.
  unsigned OpndIdx = 0;
  for (unsigned OpndEnd = MBBI->getNumOperands() - 1; OpndIdx < OpndEnd;
       ++OpndIdx)
    MIB.add(MBBI->getOperand(OpndIdx));

  assert(MBBI->getOperand(OpndIdx).getImm() == 0 &&
         "Unexpected immediate offset in first/last callee-save save/restore "
         "instruction!");
  assert(MBBI->getOperand(OpndIdx - 1).getReg() == AArch64::SP &&
         "Unexpected base register in callee-save save/restore instruction!");
  // Last operand is immediate offset that needs fixing.
  assert(CSStackSizeInc % 8 == 0);
  int64_t CSStackSizeIncImm = CSStackSizeInc;
  if (!NewIsUnscaled)
    CSStackSizeIncImm /= 8;
  MIB.addImm(CSStackSizeIncImm);

  MIB.setMIFlags(MBBI->getFlags());
  MIB.setMemRefs(MBBI->memoperands_begin(), MBBI->memoperands_end());

  return std::prev(MBB.erase(MBBI));
}