// This file contains the Mips16 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
-
#include "Mips16InstrInfo.h"
-#include "MipsTargetMachine.h"
-#include "MipsMachineFunction.h"
#include "InstPrinter/MipsInstPrinter.h"
+#include "MipsMachineFunction.h"
+#include "MipsTargetMachine.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cctype>
using namespace llvm;
-Mips16InstrInfo::Mips16InstrInfo(MipsTargetMachine &tm)
- : MipsInstrInfo(tm, /* FIXME: set mips16 unconditional br */ 0),
- RI(*tm.getSubtargetImpl()) {}
+#define DEBUG_TYPE "mips16-instrinfo"
+
+Mips16InstrInfo::Mips16InstrInfo(const MipsSubtarget &STI)
+ : MipsInstrInfo(STI, Mips::Bimm16), RI() {}
const MipsRegisterInfo &Mips16InstrInfo::getRegisterInfo() const {
return RI;
/// the destination along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than loading from the stack slot.
-unsigned Mips16InstrInfo::
-isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const
-{
+unsigned Mips16InstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
+ int &FrameIndex) const {
return 0;
}
/// the source reg along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than storing to the stack slot.
-unsigned Mips16InstrInfo::
-isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const
-{
+unsigned Mips16InstrInfo::isStoreToStackSlot(const MachineInstr *MI,
+ int &FrameIndex) const {
return 0;
}
unsigned Opc = 0;
if (Mips::CPU16RegsRegClass.contains(DestReg) &&
- Mips::CPURegsRegClass.contains(SrcReg))
+ Mips::GPR32RegClass.contains(SrcReg))
Opc = Mips::MoveR3216;
- else if (Mips::CPURegsRegClass.contains(DestReg) &&
+ else if (Mips::GPR32RegClass.contains(DestReg) &&
Mips::CPU16RegsRegClass.contains(SrcReg))
Opc = Mips::Move32R16;
- else if ((SrcReg == Mips::HI) &&
+ else if ((SrcReg == Mips::HI0) &&
(Mips::CPU16RegsRegClass.contains(DestReg)))
Opc = Mips::Mfhi16, SrcReg = 0;
- else if ((SrcReg == Mips::LO) &&
+ else if ((SrcReg == Mips::LO0) &&
(Mips::CPU16RegsRegClass.contains(DestReg)))
Opc = Mips::Mflo16, SrcReg = 0;
MIB.addReg(SrcReg, getKillRegState(KillSrc));
}
-void Mips16InstrInfo::
-storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
- unsigned SrcReg, bool isKill, int FI,
- const TargetRegisterClass *RC,
- const TargetRegisterInfo *TRI) const {
+void Mips16InstrInfo::storeRegToStack(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I,
+ unsigned SrcReg, bool isKill, int FI,
+ const TargetRegisterClass *RC,
+ const TargetRegisterInfo *TRI,
+ int64_t Offset) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOStore);
if (Mips::CPU16RegsRegClass.hasSubClassEq(RC))
Opc = Mips::SwRxSpImmX16;
assert(Opc && "Register class not handled!");
- BuildMI(MBB, I, DL, get(Opc)).addReg(SrcReg, getKillRegState(isKill))
- .addFrameIndex(FI).addImm(0).addMemOperand(MMO);
+ BuildMI(MBB, I, DL, get(Opc)).addReg(SrcReg, getKillRegState(isKill)).
+ addFrameIndex(FI).addImm(Offset)
+ .addMemOperand(MMO);
}
-void Mips16InstrInfo::
-loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
- unsigned DestReg, int FI,
- const TargetRegisterClass *RC,
- const TargetRegisterInfo *TRI) const {
+void Mips16InstrInfo::loadRegFromStack(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I,
+ unsigned DestReg, int FI,
+ const TargetRegisterClass *RC,
+ const TargetRegisterInfo *TRI,
+ int64_t Offset) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOLoad);
if (Mips::CPU16RegsRegClass.hasSubClassEq(RC))
Opc = Mips::LwRxSpImmX16;
assert(Opc && "Register class not handled!");
- BuildMI(MBB, I, DL, get(Opc), DestReg).addFrameIndex(FI).addImm(0)
+ BuildMI(MBB, I, DL, get(Opc), DestReg).addFrameIndex(FI).addImm(Offset)
.addMemOperand(MMO);
}
bool Mips16InstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const {
MachineBasicBlock &MBB = *MI->getParent();
-
switch(MI->getDesc().getOpcode()) {
default:
return false;
case Mips::RetRA16:
- ExpandRetRA16(MBB, MI, Mips::JrRa16);
+ ExpandRetRA16(MBB, MI, Mips::JrcRa16);
break;
}
/// GetOppositeBranchOpc - Return the inverse of the specified
/// opcode, e.g. turning BEQ to BNE.
-unsigned Mips16InstrInfo::GetOppositeBranchOpc(unsigned Opc) const {
- assert(false && "Implement this function.");
- return 0;
+unsigned Mips16InstrInfo::getOppositeBranchOpc(unsigned Opc) const {
+ switch (Opc) {
+ case Mips::BeqzRxImmX16: return Mips::BnezRxImmX16;
+ case Mips::BnezRxImmX16: return Mips::BeqzRxImmX16;
+ case Mips::BeqzRxImm16: return Mips::BnezRxImm16;
+ case Mips::BnezRxImm16: return Mips::BeqzRxImm16;
+ case Mips::BteqzT8CmpX16: return Mips::BtnezT8CmpX16;
+ case Mips::BteqzT8SltX16: return Mips::BtnezT8SltX16;
+ case Mips::BteqzT8SltiX16: return Mips::BtnezT8SltiX16;
+ case Mips::Btnez16: return Mips::Bteqz16;
+ case Mips::BtnezX16: return Mips::BteqzX16;
+ case Mips::BtnezT8CmpiX16: return Mips::BteqzT8CmpiX16;
+ case Mips::BtnezT8SltuX16: return Mips::BteqzT8SltuX16;
+ case Mips::BtnezT8SltiuX16: return Mips::BteqzT8SltiuX16;
+ case Mips::Bteqz16: return Mips::Btnez16;
+ case Mips::BteqzX16: return Mips::BtnezX16;
+ case Mips::BteqzT8CmpiX16: return Mips::BtnezT8CmpiX16;
+ case Mips::BteqzT8SltuX16: return Mips::BtnezT8SltuX16;
+ case Mips::BteqzT8SltiuX16: return Mips::BtnezT8SltiuX16;
+ case Mips::BtnezT8CmpX16: return Mips::BteqzT8CmpX16;
+ case Mips::BtnezT8SltX16: return Mips::BteqzT8SltX16;
+ case Mips::BtnezT8SltiX16: return Mips::BteqzT8SltiX16;
+ }
+ llvm_unreachable("Illegal opcode!");
}
-unsigned Mips16InstrInfo::GetAnalyzableBrOpc(unsigned Opc) const {
- return 0;
+static void addSaveRestoreRegs(MachineInstrBuilder &MIB,
+ const std::vector<CalleeSavedInfo> &CSI,
+ unsigned Flags = 0) {
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ // Add the callee-saved register as live-in. Do not add if the register is
+ // RA and return address is taken, because it has already been added in
+ // method MipsTargetLowering::LowerRETURNADDR.
+ // It's killed at the spill, unless the register is RA and return address
+ // is taken.
+ unsigned Reg = CSI[e-i-1].getReg();
+ switch (Reg) {
+ case Mips::RA:
+ case Mips::S0:
+ case Mips::S1:
+ MIB.addReg(Reg, Flags);
+ break;
+ case Mips::S2:
+ break;
+ default:
+ llvm_unreachable("unexpected mips16 callee saved register");
+
+ }
+ }
+}
+// Adjust SP by FrameSize bytes. Save RA, S0, S1
+void Mips16InstrInfo::makeFrame(unsigned SP, int64_t FrameSize,
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I) const {
+ DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+ MachineFunction &MF = *MBB.getParent();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ const BitVector Reserved = RI.getReservedRegs(MF);
+ bool SaveS2 = Reserved[Mips::S2];
+ MachineInstrBuilder MIB;
+ unsigned Opc = ((FrameSize <= 128) && !SaveS2)? Mips::Save16:Mips::SaveX16;
+ MIB = BuildMI(MBB, I, DL, get(Opc));
+ const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+ addSaveRestoreRegs(MIB, CSI);
+ if (SaveS2)
+ MIB.addReg(Mips::S2);
+ if (isUInt<11>(FrameSize))
+ MIB.addImm(FrameSize);
+ else {
+ int Base = 2040; // should create template function like isUInt that
+ // returns largest possible n bit unsigned integer
+ int64_t Remainder = FrameSize - Base;
+ MIB.addImm(Base);
+ if (isInt<16>(-Remainder))
+ BuildAddiuSpImm(MBB, I, -Remainder);
+ else
+ adjustStackPtrBig(SP, -Remainder, MBB, I, Mips::V0, Mips::V1);
+ }
+}
+
+// Adjust SP by FrameSize bytes. Restore RA, S0, S1
+void Mips16InstrInfo::restoreFrame(unsigned SP, int64_t FrameSize,
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I) const {
+ DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+ MachineFunction *MF = MBB.getParent();
+ MachineFrameInfo *MFI = MF->getFrameInfo();
+ const BitVector Reserved = RI.getReservedRegs(*MF);
+ bool SaveS2 = Reserved[Mips::S2];
+ MachineInstrBuilder MIB;
+ unsigned Opc = ((FrameSize <= 128) && !SaveS2)?
+ Mips::Restore16:Mips::RestoreX16;
+
+ if (!isUInt<11>(FrameSize)) {
+ unsigned Base = 2040;
+ int64_t Remainder = FrameSize - Base;
+ FrameSize = Base; // should create template function like isUInt that
+ // returns largest possible n bit unsigned integer
+
+ if (isInt<16>(Remainder))
+ BuildAddiuSpImm(MBB, I, Remainder);
+ else
+ adjustStackPtrBig(SP, Remainder, MBB, I, Mips::A0, Mips::A1);
+ }
+ MIB = BuildMI(MBB, I, DL, get(Opc));
+ const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+ addSaveRestoreRegs(MIB, CSI, RegState::Define);
+ if (SaveS2)
+ MIB.addReg(Mips::S2, RegState::Define);
+ MIB.addImm(FrameSize);
+}
+
+// Adjust SP by Amount bytes where bytes can be up to 32bit number.
+// This can only be called at times that we know that there is at least one free
+// register.
+// This is clearly safe at prologue and epilogue.
+//
+void Mips16InstrInfo::adjustStackPtrBig(unsigned SP, int64_t Amount,
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I,
+ unsigned Reg1, unsigned Reg2) const {
+ DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+ //
+ // li reg1, constant
+ // move reg2, sp
+ // add reg1, reg1, reg2
+ // move sp, reg1
+ //
+ //
+ MachineInstrBuilder MIB1 = BuildMI(MBB, I, DL, get(Mips::LwConstant32), Reg1);
+ MIB1.addImm(Amount).addImm(-1);
+ MachineInstrBuilder MIB2 = BuildMI(MBB, I, DL, get(Mips::MoveR3216), Reg2);
+ MIB2.addReg(Mips::SP, RegState::Kill);
+ MachineInstrBuilder MIB3 = BuildMI(MBB, I, DL, get(Mips::AdduRxRyRz16), Reg1);
+ MIB3.addReg(Reg1);
+ MIB3.addReg(Reg2, RegState::Kill);
+ MachineInstrBuilder MIB4 = BuildMI(MBB, I, DL, get(Mips::Move32R16),
+ Mips::SP);
+ MIB4.addReg(Reg1, RegState::Kill);
+}
+
+void Mips16InstrInfo::adjustStackPtrBigUnrestricted(
+ unsigned SP, int64_t Amount, MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I) const {
+ llvm_unreachable("adjust stack pointer amount exceeded");
+}
+
+/// Adjust SP by Amount bytes.
+void Mips16InstrInfo::adjustStackPtr(unsigned SP, int64_t Amount,
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I) const {
+ if (Amount == 0)
+ return;
+
+ if (isInt<16>(Amount)) // need to change to addiu sp, ....and isInt<16>
+ BuildAddiuSpImm(MBB, I, Amount);
+ else
+ adjustStackPtrBigUnrestricted(SP, Amount, MBB, I);
+}
+
+/// This function generates the sequence of instructions needed to get the
+/// result of adding register REG and immediate IMM.
+unsigned Mips16InstrInfo::loadImmediate(unsigned FrameReg, int64_t Imm,
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator II,
+ DebugLoc DL, unsigned &NewImm) const {
+ //
+ // given original instruction is:
+ // Instr rx, T[offset] where offset is too big.
+ //
+ // lo = offset & 0xFFFF
+ // hi = ((offset >> 16) + (lo >> 15)) & 0xFFFF;
+ //
+ // let T = temporary register
+ // li T, hi
+ // shl T, 16
+ // add T, Rx, T
+ //
+ RegScavenger rs;
+ int32_t lo = Imm & 0xFFFF;
+ NewImm = lo;
+ int Reg =0;
+ int SpReg = 0;
+
+ rs.enterBasicBlock(&MBB);
+ rs.forward(II);
+ //
+ // We need to know which registers can be used, in the case where there
+ // are not enough free registers. We exclude all registers that
+ // are used in the instruction that we are helping.
+ // // Consider all allocatable registers in the register class initially
+ BitVector Candidates =
+ RI.getAllocatableSet
+ (*II->getParent()->getParent(), &Mips::CPU16RegsRegClass);
+ // Exclude all the registers being used by the instruction.
+ for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = II->getOperand(i);
+ if (MO.isReg() && MO.getReg() != 0 && !MO.isDef() &&
+ !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
+ Candidates.reset(MO.getReg());
+ }
+
+ // If the same register was used and defined in an instruction, then
+ // it will not be in the list of candidates.
+ //
+ // we need to analyze the instruction that we are helping.
+ // we need to know if it defines register x but register x is not
+ // present as an operand of the instruction. this tells
+ // whether the register is live before the instruction. if it's not
+ // then we don't need to save it in case there are no free registers.
+ int DefReg = 0;
+ for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = II->getOperand(i);
+ if (MO.isReg() && MO.isDef()) {
+ DefReg = MO.getReg();
+ break;
+ }
+ }
+
+ BitVector Available = rs.getRegsAvailable(&Mips::CPU16RegsRegClass);
+ Available &= Candidates;
+ //
+ // we use T0 for the first register, if we need to save something away.
+ // we use T1 for the second register, if we need to save something away.
+ //
+ unsigned FirstRegSaved =0, SecondRegSaved=0;
+ unsigned FirstRegSavedTo = 0, SecondRegSavedTo = 0;
+
+ Reg = Available.find_first();
+
+ if (Reg == -1) {
+ Reg = Candidates.find_first();
+ Candidates.reset(Reg);
+ if (DefReg != Reg) {
+ FirstRegSaved = Reg;
+ FirstRegSavedTo = Mips::T0;
+ copyPhysReg(MBB, II, DL, FirstRegSavedTo, FirstRegSaved, true);
+ }
+ }
+ else
+ Available.reset(Reg);
+ BuildMI(MBB, II, DL, get(Mips::LwConstant32), Reg).addImm(Imm).addImm(-1);
+ NewImm = 0;
+ if (FrameReg == Mips::SP) {
+ SpReg = Available.find_first();
+ if (SpReg == -1) {
+ SpReg = Candidates.find_first();
+ // Candidates.reset(SpReg); // not really needed
+ if (DefReg!= SpReg) {
+ SecondRegSaved = SpReg;
+ SecondRegSavedTo = Mips::T1;
+ }
+ if (SecondRegSaved)
+ copyPhysReg(MBB, II, DL, SecondRegSavedTo, SecondRegSaved, true);
+ }
+ else
+ Available.reset(SpReg);
+ copyPhysReg(MBB, II, DL, SpReg, Mips::SP, false);
+ BuildMI(MBB, II, DL, get(Mips:: AdduRxRyRz16), Reg).addReg(SpReg, RegState::Kill)
+ .addReg(Reg);
+ }
+ else
+ BuildMI(MBB, II, DL, get(Mips:: AdduRxRyRz16), Reg).addReg(FrameReg)
+ .addReg(Reg, RegState::Kill);
+ if (FirstRegSaved || SecondRegSaved) {
+ II = std::next(II);
+ if (FirstRegSaved)
+ copyPhysReg(MBB, II, DL, FirstRegSaved, FirstRegSavedTo, true);
+ if (SecondRegSaved)
+ copyPhysReg(MBB, II, DL, SecondRegSaved, SecondRegSavedTo, true);
+ }
+ return Reg;
+}
+
+unsigned Mips16InstrInfo::getAnalyzableBrOpc(unsigned Opc) const {
+ return (Opc == Mips::BeqzRxImmX16 || Opc == Mips::BimmX16 ||
+ Opc == Mips::Bimm16 ||
+ Opc == Mips::Bteqz16 || Opc == Mips::Btnez16 ||
+ Opc == Mips::BeqzRxImm16 || Opc == Mips::BnezRxImm16 ||
+ Opc == Mips::BnezRxImmX16 || Opc == Mips::BteqzX16 ||
+ Opc == Mips::BteqzT8CmpX16 || Opc == Mips::BteqzT8CmpiX16 ||
+ Opc == Mips::BteqzT8SltX16 || Opc == Mips::BteqzT8SltuX16 ||
+ Opc == Mips::BteqzT8SltiX16 || Opc == Mips::BteqzT8SltiuX16 ||
+ Opc == Mips::BtnezX16 || Opc == Mips::BtnezT8CmpX16 ||
+ Opc == Mips::BtnezT8CmpiX16 || Opc == Mips::BtnezT8SltX16 ||
+ Opc == Mips::BtnezT8SltuX16 || Opc == Mips::BtnezT8SltiX16 ||
+ Opc == Mips::BtnezT8SltiuX16 ) ? Opc : 0;
}
void Mips16InstrInfo::ExpandRetRA16(MachineBasicBlock &MBB,
BuildMI(MBB, I, I->getDebugLoc(), get(Opc));
}
-const MipsInstrInfo *llvm::createMips16InstrInfo(MipsTargetMachine &TM) {
- return new Mips16InstrInfo(TM);
+const MCInstrDesc &Mips16InstrInfo::AddiuSpImm(int64_t Imm) const {
+ if (validSpImm8(Imm))
+ return get(Mips::AddiuSpImm16);
+ else
+ return get(Mips::AddiuSpImmX16);
+}
+
+void Mips16InstrInfo::BuildAddiuSpImm
+ (MachineBasicBlock &MBB, MachineBasicBlock::iterator I, int64_t Imm) const {
+ DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+ BuildMI(MBB, I, DL, AddiuSpImm(Imm)).addImm(Imm);
+}
+
+const MipsInstrInfo *llvm::createMips16InstrInfo(const MipsSubtarget &STI) {
+ return new Mips16InstrInfo(STI);
+}
+
+bool Mips16InstrInfo::validImmediate(unsigned Opcode, unsigned Reg,
+ int64_t Amount) {
+ switch (Opcode) {
+ case Mips::LbRxRyOffMemX16:
+ case Mips::LbuRxRyOffMemX16:
+ case Mips::LhRxRyOffMemX16:
+ case Mips::LhuRxRyOffMemX16:
+ case Mips::SbRxRyOffMemX16:
+ case Mips::ShRxRyOffMemX16:
+ case Mips::LwRxRyOffMemX16:
+ case Mips::SwRxRyOffMemX16:
+ case Mips::SwRxSpImmX16:
+ case Mips::LwRxSpImmX16:
+ return isInt<16>(Amount);
+ case Mips::AddiuRxRyOffMemX16:
+ if ((Reg == Mips::PC) || (Reg == Mips::SP))
+ return isInt<16>(Amount);
+ return isInt<15>(Amount);
+ }
+ llvm_unreachable("unexpected Opcode in validImmediate");
+}
+
+/// Measure the specified inline asm to determine an approximation of its
+/// length.
+/// Comments (which run till the next SeparatorString or newline) do not
+/// count as an instruction.
+/// Any other non-whitespace text is considered an instruction, with
+/// multiple instructions separated by SeparatorString or newlines.
+/// Variable-length instructions are not handled here; this function
+/// may be overloaded in the target code to do that.
+/// We implement the special case of the .space directive taking only an
+/// integer argument, which is the size in bytes. This is used for creating
+/// inline code spacing for testing purposes using inline assembly.
+///
+unsigned Mips16InstrInfo::getInlineAsmLength(const char *Str,
+ const MCAsmInfo &MAI) const {
+
+ // Count the number of instructions in the asm.
+ bool atInsnStart = true;
+ unsigned Length = 0;
+ for (; *Str; ++Str) {
+ if (*Str == '\n' || strncmp(Str, MAI.getSeparatorString(),
+ strlen(MAI.getSeparatorString())) == 0)
+ atInsnStart = true;
+ if (atInsnStart && !std::isspace(static_cast<unsigned char>(*Str))) {
+ if (strncmp(Str, ".space", 6)==0) {
+ char *EStr; int Sz;
+ Sz = strtol(Str+6, &EStr, 10);
+ while (isspace(*EStr)) ++EStr;
+ if (*EStr=='\0') {
+ DEBUG(dbgs() << "parsed .space " << Sz << '\n');
+ return Sz;
+ }
+ }
+ Length += MAI.getMaxInstLength();
+ atInsnStart = false;
+ }
+ if (atInsnStart && strncmp(Str, MAI.getCommentString(),
+ strlen(MAI.getCommentString())) == 0)
+ atInsnStart = false;
+ }
+
+ return Length;
}