Updating branches/google/stable to r176857

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/google/stable@177040 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 822 insertions, 0 deletions

diff --git a/lib/Target/AArch64/AArch64InstrInfo.cpp b/lib/Target/AArch64/AArch64InstrInfo.cpp
new file mode 100644
index 0000000000..7b93463244
--- /dev/null
+++ b/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -0,0 +1,822 @@
+//===- AArch64InstrInfo.cpp - AArch64 Instruction Information -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the AArch64 implementation of the TargetInstrInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AArch64.h"
+#include "AArch64InstrInfo.h"
+#include "AArch64MachineFunctionInfo.h"
+#include "AArch64TargetMachine.h"
+#include "MCTargetDesc/AArch64MCTargetDesc.h"
+#include "Utils/AArch64BaseInfo.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetRegistry.h"
+
+#include <algorithm>
+
+#define GET_INSTRINFO_CTOR
+#include "AArch64GenInstrInfo.inc"
+
+using namespace llvm;
+
+AArch64InstrInfo::AArch64InstrInfo(const AArch64Subtarget &STI)
+  : AArch64GenInstrInfo(AArch64::ADJCALLSTACKDOWN, AArch64::ADJCALLSTACKUP),
+    RI(*this, STI), Subtarget(STI) {}
+
+void AArch64InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
+                                   MachineBasicBlock::iterator I, DebugLoc DL,
+                                   unsigned DestReg, unsigned SrcReg,
+                                   bool KillSrc) const {
+  unsigned Opc = 0;
+  unsigned ZeroReg = 0;
+  if (DestReg == AArch64::XSP || SrcReg == AArch64::XSP) {
+    // E.g. ADD xDst, xsp, #0 (, lsl #0)
+    BuildMI(MBB, I, DL, get(AArch64::ADDxxi_lsl0_s), DestReg)
+      .addReg(SrcReg)
+      .addImm(0);
+    return;
+  } else if (DestReg == AArch64::WSP || SrcReg == AArch64::WSP) {
+    // E.g. ADD wDST, wsp, #0 (, lsl #0)
+    BuildMI(MBB, I, DL, get(AArch64::ADDwwi_lsl0_s), DestReg)
+      .addReg(SrcReg)
+      .addImm(0);
+    return;
+  } else if (DestReg == AArch64::NZCV) {
+    assert(AArch64::GPR64RegClass.contains(SrcReg));
+    // E.g. MSR NZCV, xDST
+    BuildMI(MBB, I, DL, get(AArch64::MSRix))
+      .addImm(A64SysReg::NZCV)
+      .addReg(SrcReg);
+  } else if (SrcReg == AArch64::NZCV) {
+    assert(AArch64::GPR64RegClass.contains(DestReg));
+    // E.g. MRS xDST, NZCV
+    BuildMI(MBB, I, DL, get(AArch64::MRSxi), DestReg)
+      .addImm(A64SysReg::NZCV);
+  } else if (AArch64::GPR64RegClass.contains(DestReg)) {
+    assert(AArch64::GPR64RegClass.contains(SrcReg));
+    Opc = AArch64::ORRxxx_lsl;
+    ZeroReg = AArch64::XZR;
+  } else if (AArch64::GPR32RegClass.contains(DestReg)) {
+    assert(AArch64::GPR32RegClass.contains(SrcReg));
+    Opc = AArch64::ORRwww_lsl;
+    ZeroReg = AArch64::WZR;
+  } else if (AArch64::FPR32RegClass.contains(DestReg)) {
+    assert(AArch64::FPR32RegClass.contains(SrcReg));
+    BuildMI(MBB, I, DL, get(AArch64::FMOVss), DestReg)
+      .addReg(SrcReg);
+    return;
+  } else if (AArch64::FPR64RegClass.contains(DestReg)) {
+    assert(AArch64::FPR64RegClass.contains(SrcReg));
+    BuildMI(MBB, I, DL, get(AArch64::FMOVdd), DestReg)
+      .addReg(SrcReg);
+    return;
+  } else if (AArch64::FPR128RegClass.contains(DestReg)) {
+    assert(AArch64::FPR128RegClass.contains(SrcReg));
+
+    // FIXME: there's no good way to do this, at least without NEON:
+    //   + There's no single move instruction for q-registers
+    //   + We can't create a spill slot and use normal STR/LDR because stack
+    //     allocation has already happened
+    //   + We can't go via X-registers with FMOV because register allocation has
+    //     already happened.
+    // This may not be efficient, but at least it works.
+    BuildMI(MBB, I, DL, get(AArch64::LSFP128_PreInd_STR), AArch64::XSP)
+      .addReg(SrcReg)
+      .addReg(AArch64::XSP)
+      .addImm(0x1ff & -16);
+
+    BuildMI(MBB, I, DL, get(AArch64::LSFP128_PostInd_LDR), DestReg)
+      .addReg(AArch64::XSP, RegState::Define)
+      .addReg(AArch64::XSP)
+      .addImm(16);
+    return;
+  } else {
+    llvm_unreachable("Unknown register class in copyPhysReg");
+  }
+
+  // E.g. ORR xDst, xzr, xSrc, lsl #0
+  BuildMI(MBB, I, DL, get(Opc), DestReg)
+    .addReg(ZeroReg)
+    .addReg(SrcReg)
+    .addImm(0);
+}
+
+MachineInstr *
+AArch64InstrInfo::emitFrameIndexDebugValue(MachineFunction &MF, int FrameIx,
+                                           uint64_t Offset, const MDNode *MDPtr,
+                                           DebugLoc DL) const {
+  MachineInstrBuilder MIB = BuildMI(MF, DL, get(AArch64::DBG_VALUE))
+    .addFrameIndex(FrameIx).addImm(0)
+    .addImm(Offset)
+    .addMetadata(MDPtr);
+  return &*MIB;
+}
+
+/// Does the Opcode represent a conditional branch that we can remove and re-add
+/// at the end of a basic block?
+static bool isCondBranch(unsigned Opc) {
+  return Opc == AArch64::Bcc || Opc == AArch64::CBZw || Opc == AArch64::CBZx ||
+         Opc == AArch64::CBNZw || Opc == AArch64::CBNZx ||
+         Opc == AArch64::TBZwii || Opc == AArch64::TBZxii ||
+         Opc == AArch64::TBNZwii || Opc == AArch64::TBNZxii;
+}
+
+/// Takes apart a given conditional branch MachineInstr (see isCondBranch),
+/// setting TBB to the destination basic block and populating the Cond vector
+/// with data necessary to recreate the conditional branch at a later
+/// date. First element will be the opcode, and subsequent ones define the
+/// conditions being branched on in an instruction-specific manner.
+static void classifyCondBranch(MachineInstr *I, MachineBasicBlock *&TBB,
+                               SmallVectorImpl<MachineOperand> &Cond) {
+  switch(I->getOpcode()) {
+  case AArch64::Bcc:
+  case AArch64::CBZw:
+  case AArch64::CBZx:
+  case AArch64::CBNZw:
+  case AArch64::CBNZx:
+    // These instructions just have one predicate operand in position 0 (either
+    // a condition code or a register being compared).
+    Cond.push_back(MachineOperand::CreateImm(I->getOpcode()));
+    Cond.push_back(I->getOperand(0));
+    TBB = I->getOperand(1).getMBB();
+    return;
+  case AArch64::TBZwii:
+  case AArch64::TBZxii:
+  case AArch64::TBNZwii:
+  case AArch64::TBNZxii:
+    // These have two predicate operands: a register and a bit position.
+    Cond.push_back(MachineOperand::CreateImm(I->getOpcode()));
+    Cond.push_back(I->getOperand(0));
+    Cond.push_back(I->getOperand(1));
+    TBB = I->getOperand(2).getMBB();
+    return;
+  default:
+    llvm_unreachable("Unknown conditional branch to classify");
+  }
+}
+
+
+bool
+AArch64InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
+                                MachineBasicBlock *&FBB,
+                                SmallVectorImpl<MachineOperand> &Cond,
+                                bool AllowModify) const {
+  // If the block has no terminators, it just falls into the block after it.
+  MachineBasicBlock::iterator I = MBB.end();
+  if (I == MBB.begin())
+    return false;
+  --I;
+  while (I->isDebugValue()) {
+    if (I == MBB.begin())
+      return false;
+    --I;
+  }
+  if (!isUnpredicatedTerminator(I))
+    return false;
+
+  // Get the last instruction in the block.
+  MachineInstr *LastInst = I;
+
+  // If there is only one terminator instruction, process it.
+  unsigned LastOpc = LastInst->getOpcode();
+  if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
+    if (LastOpc == AArch64::Bimm) {
+      TBB = LastInst->getOperand(0).getMBB();
+      return false;
+    }
+    if (isCondBranch(LastOpc)) {
+      classifyCondBranch(LastInst, TBB, Cond);
+      return false;
+    }
+    return true;  // Can't handle indirect branch.
+  }
+
+  // Get the instruction before it if it is a terminator.
+  MachineInstr *SecondLastInst = I;
+  unsigned SecondLastOpc = SecondLastInst->getOpcode();
+
+  // If AllowModify is true and the block ends with two or more unconditional
+  // branches, delete all but the first unconditional branch.
+  if (AllowModify && LastOpc == AArch64::Bimm) {
+    while (SecondLastOpc == AArch64::Bimm) {
+      LastInst->eraseFromParent();
+      LastInst = SecondLastInst;
+      LastOpc = LastInst->getOpcode();
+      if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
+        // Return now the only terminator is an unconditional branch.
+        TBB = LastInst->getOperand(0).getMBB();
+        return false;
+      } else {
+        SecondLastInst = I;
+        SecondLastOpc = SecondLastInst->getOpcode();
+      }
+    }
+  }
+
+  // If there are three terminators, we don't know what sort of block this is.
+  if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(--I))
+    return true;
+
+  // If the block ends with a B and a Bcc, handle it.
+  if (LastOpc == AArch64::Bimm) {
+    if (SecondLastOpc == AArch64::Bcc) {
+      TBB =  SecondLastInst->getOperand(1).getMBB();
+      Cond.push_back(MachineOperand::CreateImm(AArch64::Bcc));
+      Cond.push_back(SecondLastInst->getOperand(0));
+      FBB = LastInst->getOperand(0).getMBB();
+      return false;
+    } else if (isCondBranch(SecondLastOpc)) {
+      classifyCondBranch(SecondLastInst, TBB, Cond);
+      FBB = LastInst->getOperand(0).getMBB();
+      return false;
+    }
+  }
+
+  // If the block ends with two unconditional branches, handle it.  The second
+  // one is not executed, so remove it.
+  if (SecondLastOpc == AArch64::Bimm && LastOpc == AArch64::Bimm) {
+    TBB = SecondLastInst->getOperand(0).getMBB();
+    I = LastInst;
+    if (AllowModify)
+      I->eraseFromParent();
+    return false;
+  }
+
+  // Otherwise, can't handle this.
+  return true;
+}
+
+bool AArch64InstrInfo::ReverseBranchCondition(
+                                  SmallVectorImpl<MachineOperand> &Cond) const {
+  switch (Cond[0].getImm()) {
+  case AArch64::Bcc: {
+    A64CC::CondCodes CC = static_cast<A64CC::CondCodes>(Cond[1].getImm());
+    CC = A64InvertCondCode(CC);
+    Cond[1].setImm(CC);
+    return false;
+  }
+  case AArch64::CBZw:
+    Cond[0].setImm(AArch64::CBNZw);
+    return false;
+  case AArch64::CBZx:
+    Cond[0].setImm(AArch64::CBNZx);
+    return false;
+  case AArch64::CBNZw:
+    Cond[0].setImm(AArch64::CBZw);
+    return false;
+  case AArch64::CBNZx:
+    Cond[0].setImm(AArch64::CBZx);
+    return false;
+  case AArch64::TBZwii:
+    Cond[0].setImm(AArch64::TBNZwii);
+    return false;
+  case AArch64::TBZxii:
+    Cond[0].setImm(AArch64::TBNZxii);
+    return false;
+  case AArch64::TBNZwii:
+    Cond[0].setImm(AArch64::TBZwii);
+    return false;
+  case AArch64::TBNZxii:
+    Cond[0].setImm(AArch64::TBZxii);
+    return false;
+  default:
+    llvm_unreachable("Unknown branch type");
+  }
+}
+
+
+unsigned
+AArch64InstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
+                               MachineBasicBlock *FBB,
+                               const SmallVectorImpl<MachineOperand> &Cond,
+                               DebugLoc DL) const {
+  if (FBB == 0 && Cond.empty()) {
+    BuildMI(&MBB, DL, get(AArch64::Bimm)).addMBB(TBB);
+    return 1;
+  } else if (FBB == 0) {
+    MachineInstrBuilder MIB = BuildMI(&MBB, DL, get(Cond[0].getImm()));
+    for (int i = 1, e = Cond.size(); i != e; ++i)
+      MIB.addOperand(Cond[i]);
+    MIB.addMBB(TBB);
+    return 1;
+  }
+
+  MachineInstrBuilder MIB = BuildMI(&MBB, DL, get(Cond[0].getImm()));
+  for (int i = 1, e = Cond.size(); i != e; ++i)
+    MIB.addOperand(Cond[i]);
+  MIB.addMBB(TBB);
+
+  BuildMI(&MBB, DL, get(AArch64::Bimm)).addMBB(FBB);
+  return 2;
+}
+
+unsigned AArch64InstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+  MachineBasicBlock::iterator I = MBB.end();
+  if (I == MBB.begin()) return 0;
+  --I;
+  while (I->isDebugValue()) {
+    if (I == MBB.begin())
+      return 0;
+    --I;
+  }
+  if (I->getOpcode() != AArch64::Bimm && !isCondBranch(I->getOpcode()))
+    return 0;
+
+  // Remove the branch.
+  I->eraseFromParent();
+
+  I = MBB.end();
+
+  if (I == MBB.begin()) return 1;
+  --I;
+  if (!isCondBranch(I->getOpcode()))
+    return 1;
+
+  // Remove the branch.
+  I->eraseFromParent();
+  return 2;
+}
+
+bool
+AArch64InstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MBBI) const {
+  MachineInstr &MI = *MBBI;
+  MachineBasicBlock &MBB = *MI.getParent();
+
+  unsigned Opcode = MI.getOpcode();
+  switch (Opcode) {
+  case AArch64::TLSDESC_BLRx: {
+    MachineInstr *NewMI =
+      BuildMI(MBB, MBBI, MI.getDebugLoc(), get(AArch64::TLSDESCCALL))
+        .addOperand(MI.getOperand(1));
+    MI.setDesc(get(AArch64::BLRx));
+
+    llvm::finalizeBundle(MBB, NewMI, *++MBBI);
+    return true;
+    }
+  default:
+    return false;
+  }
+
+  return false;
+}
+
+void
+AArch64InstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
+                                      MachineBasicBlock::iterator MBBI,
+                                      unsigned SrcReg, bool isKill,
+                                      int FrameIdx,
+                                      const TargetRegisterClass *RC,
+                                      const TargetRegisterInfo *TRI) const {
+  DebugLoc DL = MBB.findDebugLoc(MBBI);
+  MachineFunction &MF = *MBB.getParent();
+  MachineFrameInfo &MFI = *MF.getFrameInfo();
+  unsigned Align = MFI.getObjectAlignment(FrameIdx);
+
+  MachineMemOperand *MMO
+    = MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FrameIdx),
+                              MachineMemOperand::MOStore,
+                              MFI.getObjectSize(FrameIdx),
+                              Align);
+
+  unsigned StoreOp = 0;
+  if (RC->hasType(MVT::i64) || RC->hasType(MVT::i32)) {
+    switch(RC->getSize()) {
+    case 4: StoreOp = AArch64::LS32_STR; break;
+    case 8: StoreOp = AArch64::LS64_STR; break;
+    default:
+      llvm_unreachable("Unknown size for regclass");
+    }
+  } else {
+    assert((RC->hasType(MVT::f32) || RC->hasType(MVT::f64) ||
+            RC->hasType(MVT::f128))
+           && "Expected integer or floating type for store");
+    switch (RC->getSize()) {
+    case 4: StoreOp = AArch64::LSFP32_STR; break;
+    case 8: StoreOp = AArch64::LSFP64_STR; break;
+    case 16: StoreOp = AArch64::LSFP128_STR; break;
+    default:
+      llvm_unreachable("Unknown size for regclass");
+    }
+  }
+
+  MachineInstrBuilder NewMI = BuildMI(MBB, MBBI, DL, get(StoreOp));
+  NewMI.addReg(SrcReg, getKillRegState(isKill))
+    .addFrameIndex(FrameIdx)
+    .addImm(0)
+    .addMemOperand(MMO);
+
+}
+
+void
+AArch64InstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
+                                       MachineBasicBlock::iterator MBBI,
+                                       unsigned DestReg, int FrameIdx,
+                                       const TargetRegisterClass *RC,
+                                       const TargetRegisterInfo *TRI) const {
+  DebugLoc DL = MBB.findDebugLoc(MBBI);
+  MachineFunction &MF = *MBB.getParent();
+  MachineFrameInfo &MFI = *MF.getFrameInfo();
+  unsigned Align = MFI.getObjectAlignment(FrameIdx);
+
+  MachineMemOperand *MMO
+    = MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FrameIdx),
+                              MachineMemOperand::MOLoad,
+                              MFI.getObjectSize(FrameIdx),
+                              Align);
+
+  unsigned LoadOp = 0;
+  if (RC->hasType(MVT::i64) || RC->hasType(MVT::i32)) {
+    switch(RC->getSize()) {
+    case 4: LoadOp = AArch64::LS32_LDR; break;
+    case 8: LoadOp = AArch64::LS64_LDR; break;
+    default:
+      llvm_unreachable("Unknown size for regclass");
+    }
+  } else {
+    assert((RC->hasType(MVT::f32) || RC->hasType(MVT::f64)
+            || RC->hasType(MVT::f128))
+           && "Expected integer or floating type for store");
+    switch (RC->getSize()) {
+    case 4: LoadOp = AArch64::LSFP32_LDR; break;
+    case 8: LoadOp = AArch64::LSFP64_LDR; break;
+    case 16: LoadOp = AArch64::LSFP128_LDR; break;
+    default:
+      llvm_unreachable("Unknown size for regclass");
+    }
+  }
+
+  MachineInstrBuilder NewMI = BuildMI(MBB, MBBI, DL, get(LoadOp), DestReg);
+  NewMI.addFrameIndex(FrameIdx)
+       .addImm(0)
+       .addMemOperand(MMO);
+}
+
+unsigned AArch64InstrInfo::estimateRSStackLimit(MachineFunction &MF) const {
+  unsigned Limit = (1 << 16) - 1;
+  for (MachineFunction::iterator BB = MF.begin(),E = MF.end(); BB != E; ++BB) {
+    for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end();
+         I != E; ++I) {
+      for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+        if (!I->getOperand(i).isFI()) continue;
+
+        // When using ADDxxi_lsl0_s to get the address of a stack object, 0xfff
+        // is the largest offset guaranteed to fit in the immediate offset.
+        if (I->getOpcode() == AArch64::ADDxxi_lsl0_s) {
+          Limit = std::min(Limit, 0xfffu);
+          break;
+        }
+
+        int AccessScale, MinOffset, MaxOffset;
+        getAddressConstraints(*I, AccessScale, MinOffset, MaxOffset);
+        Limit = std::min(Limit, static_cast<unsigned>(MaxOffset));
+
+        break; // At most one FI per instruction
+      }
+    }
+  }
+
+  return Limit;
+}
+void AArch64InstrInfo::getAddressConstraints(const MachineInstr &MI,
+                                             int &AccessScale, int &MinOffset,
+                                             int &MaxOffset) const {
+  switch (MI.getOpcode()) {
+  default: llvm_unreachable("Unkown load/store kind");
+  case TargetOpcode::DBG_VALUE:
+    AccessScale = 1;
+    MinOffset = INT_MIN;
+    MaxOffset = INT_MAX;
+    return;
+  case AArch64::LS8_LDR: case AArch64::LS8_STR:
+  case AArch64::LSFP8_LDR: case AArch64::LSFP8_STR:
+  case AArch64::LDRSBw:
+  case AArch64::LDRSBx:
+    AccessScale = 1;
+    MinOffset = 0;
+    MaxOffset = 0xfff;
+    return;
+  case AArch64::LS16_LDR: case AArch64::LS16_STR:
+  case AArch64::LSFP16_LDR: case AArch64::LSFP16_STR:
+  case AArch64::LDRSHw:
+  case AArch64::LDRSHx:
+    AccessScale = 2;
+    MinOffset = 0;
+    MaxOffset = 0xfff * AccessScale;
+    return;
+  case AArch64::LS32_LDR:  case AArch64::LS32_STR:
+  case AArch64::LSFP32_LDR: case AArch64::LSFP32_STR:
+  case AArch64::LDRSWx:
+  case AArch64::LDPSWx:
+    AccessScale = 4;
+    MinOffset = 0;
+    MaxOffset = 0xfff * AccessScale;
+    return;
+  case AArch64::LS64_LDR: case AArch64::LS64_STR:
+  case AArch64::LSFP64_LDR: case AArch64::LSFP64_STR:
+  case AArch64::PRFM:
+    AccessScale = 8;
+    MinOffset = 0;
+    MaxOffset = 0xfff * AccessScale;
+    return;
+  case AArch64::LSFP128_LDR: case AArch64::LSFP128_STR:
+    AccessScale = 16;
+    MinOffset = 0;
+    MaxOffset = 0xfff * AccessScale;
+    return;
+  case AArch64::LSPair32_LDR: case AArch64::LSPair32_STR:
+  case AArch64::LSFPPair32_LDR: case AArch64::LSFPPair32_STR:
+    AccessScale = 4;
+    MinOffset = -0x40 * AccessScale;
+    MaxOffset = 0x3f * AccessScale;
+    return;
+  case AArch64::LSPair64_LDR: case AArch64::LSPair64_STR:
+  case AArch64::LSFPPair64_LDR: case AArch64::LSFPPair64_STR:
+    AccessScale = 8;
+    MinOffset = -0x40 * AccessScale;
+    MaxOffset = 0x3f * AccessScale;
+    return;
+  case AArch64::LSFPPair128_LDR: case AArch64::LSFPPair128_STR:
+    AccessScale = 16;
+    MinOffset = -0x40 * AccessScale;
+    MaxOffset = 0x3f * AccessScale;
+    return;
+  }
+}
+
+unsigned AArch64InstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
+  const MCInstrDesc &MCID = MI.getDesc();
+  const MachineBasicBlock &MBB = *MI.getParent();
+  const MachineFunction &MF = *MBB.getParent();
+  const MCAsmInfo &MAI = *MF.getTarget().getMCAsmInfo();
+
+  if (MCID.getSize())
+    return MCID.getSize();
+
+  if (MI.getOpcode() == AArch64::INLINEASM)
+    return getInlineAsmLength(MI.getOperand(0).getSymbolName(), MAI);
+
+  if (MI.isLabel())
+    return 0;
+
+  switch (MI.getOpcode()) {
+  case TargetOpcode::BUNDLE:
+    return getInstBundleLength(MI);
+  case TargetOpcode::IMPLICIT_DEF:
+  case TargetOpcode::KILL:
+  case TargetOpcode::PROLOG_LABEL:
+  case TargetOpcode::EH_LABEL:
+  case TargetOpcode::DBG_VALUE:
+    return 0;
+  case AArch64::TLSDESCCALL:
+    return 0;
+  default:
+    llvm_unreachable("Unknown instruction class");
+  }
+}
+
+unsigned AArch64InstrInfo::getInstBundleLength(const MachineInstr &MI) const {
+  unsigned Size = 0;
+  MachineBasicBlock::const_instr_iterator I = MI;
+  MachineBasicBlock::const_instr_iterator E = MI.getParent()->instr_end();
+  while (++I != E && I->isInsideBundle()) {
+    assert(!I->isBundle() && "No nested bundle!");
+    Size += getInstSizeInBytes(*I);
+  }
+  return Size;
+}
+
+bool llvm::rewriteA64FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
+                                unsigned FrameReg, int &Offset,
+                                const AArch64InstrInfo &TII) {
+  MachineBasicBlock &MBB = *MI.getParent();
+  MachineFunction &MF = *MBB.getParent();
+  MachineFrameInfo &MFI = *MF.getFrameInfo();
+
+  MFI.getObjectOffset(FrameRegIdx);
+  llvm_unreachable("Unimplemented rewriteFrameIndex");
+}
+
+void llvm::emitRegUpdate(MachineBasicBlock &MBB,
+                         MachineBasicBlock::iterator MBBI,
+                         DebugLoc dl, const TargetInstrInfo &TII,
+                         unsigned DstReg, unsigned SrcReg, unsigned ScratchReg,
+                         int64_t NumBytes, MachineInstr::MIFlag MIFlags) {
+  if (NumBytes == 0 && DstReg == SrcReg)
+    return;
+  else if (abs(NumBytes) & ~0xffffff) {
+    // Generically, we have to materialize the offset into a temporary register
+    // and subtract it. There are a couple of ways this could be done, for now
+    // we'll use a movz/movk or movn/movk sequence.
+    uint64_t Bits = static_cast<uint64_t>(abs(NumBytes));
+    BuildMI(MBB, MBBI, dl, TII.get(AArch64::MOVZxii), ScratchReg)
+      .addImm(0xffff & Bits).addImm(0)
+      .setMIFlags(MIFlags);
+
+    Bits >>= 16;
+    if (Bits & 0xffff) {
+      BuildMI(MBB, MBBI, dl, TII.get(AArch64::MOVKxii), ScratchReg)
+        .addReg(ScratchReg)
+        .addImm(0xffff & Bits).addImm(1)
+        .setMIFlags(MIFlags);
+    }
+
+    Bits >>= 16;
+    if (Bits & 0xffff) {
+      BuildMI(MBB, MBBI, dl, TII.get(AArch64::MOVKxii), ScratchReg)
+        .addReg(ScratchReg)
+        .addImm(0xffff & Bits).addImm(2)
+        .setMIFlags(MIFlags);
+    }
+
+    Bits >>= 16;
+    if (Bits & 0xffff) {
+      BuildMI(MBB, MBBI, dl, TII.get(AArch64::MOVKxii), ScratchReg)
+        .addReg(ScratchReg)
+        .addImm(0xffff & Bits).addImm(3)
+        .setMIFlags(MIFlags);
+    }
+
+    // ADD DST, SRC, xTMP (, lsl #0)
+    unsigned AddOp = NumBytes > 0 ? AArch64::ADDxxx_uxtx : AArch64::SUBxxx_uxtx;
+    BuildMI(MBB, MBBI, dl, TII.get(AddOp), DstReg)
+      .addReg(SrcReg, RegState::Kill)
+      .addReg(ScratchReg, RegState::Kill)
+      .addImm(0)
+      .setMIFlag(MIFlags);
+    return;
+  }
+
+  // Now we know that the adjustment can be done in at most two add/sub
+  // (immediate) instructions, which is always more efficient than a
+  // literal-pool load, or even a hypothetical movz/movk/add sequence
+
+  // Decide whether we're doing addition or subtraction
+  unsigned LowOp, HighOp;
+  if (NumBytes >= 0) {
+    LowOp = AArch64::ADDxxi_lsl0_s;
+    HighOp = AArch64::ADDxxi_lsl12_s;
+  } else {
+    LowOp = AArch64::SUBxxi_lsl0_s;
+    HighOp = AArch64::SUBxxi_lsl12_s;
+    NumBytes = abs(NumBytes);
+  }
+
+  // If we're here, at the very least a move needs to be produced, which just
+  // happens to be materializable by an ADD.
+  if ((NumBytes & 0xfff) || NumBytes == 0) {
+    BuildMI(MBB, MBBI, dl, TII.get(LowOp), DstReg)
+      .addReg(SrcReg, RegState::Kill)
+      .addImm(NumBytes & 0xfff)
+      .setMIFlag(MIFlags);
+
+    // Next update should use the register we've just defined.
+    SrcReg = DstReg;
+  }
+
+  if (NumBytes & 0xfff000) {
+    BuildMI(MBB, MBBI, dl, TII.get(HighOp), DstReg)
+      .addReg(SrcReg, RegState::Kill)
+      .addImm(NumBytes >> 12)
+      .setMIFlag(MIFlags);
+  }
+}
+
+void llvm::emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
+                        DebugLoc dl, const TargetInstrInfo &TII,
+                        unsigned ScratchReg, int64_t NumBytes,
+                        MachineInstr::MIFlag MIFlags) {
+  emitRegUpdate(MBB, MI, dl, TII, AArch64::XSP, AArch64::XSP, AArch64::X16,
+                NumBytes, MIFlags);
+}
+
+
+namespace {
+  struct LDTLSCleanup : public MachineFunctionPass {
+    static char ID;
+    LDTLSCleanup() : MachineFunctionPass(ID) {}
+
+    virtual bool runOnMachineFunction(MachineFunction &MF) {
+      AArch64MachineFunctionInfo* MFI
+        = MF.getInfo<AArch64MachineFunctionInfo>();
+      if (MFI->getNumLocalDynamicTLSAccesses() < 2) {
+        // No point folding accesses if there isn't at least two.
+        return false;
+      }
+
+      MachineDominatorTree *DT = &getAnalysis<MachineDominatorTree>();
+      return VisitNode(DT->getRootNode(), 0);
+    }
+
+    // Visit the dominator subtree rooted at Node in pre-order.
+    // If TLSBaseAddrReg is non-null, then use that to replace any
+    // TLS_base_addr instructions. Otherwise, create the register
+    // when the first such instruction is seen, and then use it
+    // as we encounter more instructions.
+    bool VisitNode(MachineDomTreeNode *Node, unsigned TLSBaseAddrReg) {
+      MachineBasicBlock *BB = Node->getBlock();
+      bool Changed = false;
+
+      // Traverse the current block.
+      for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;
+           ++I) {
+        switch (I->getOpcode()) {
+        case AArch64::TLSDESC_BLRx:
+          // Make sure it's a local dynamic access.
+          if (!I->getOperand(1).isSymbol() ||
+              strcmp(I->getOperand(1).getSymbolName(), "_TLS_MODULE_BASE_"))
+            break;
+
+          if (TLSBaseAddrReg)
+            I = ReplaceTLSBaseAddrCall(I, TLSBaseAddrReg);
+          else
+            I = SetRegister(I, &TLSBaseAddrReg);
+          Changed = true;
+          break;
+        default:
+          break;
+        }
+      }
+
+      // Visit the children of this block in the dominator tree.
+      for (MachineDomTreeNode::iterator I = Node->begin(), E = Node->end();
+           I != E; ++I) {
+        Changed |= VisitNode(*I, TLSBaseAddrReg);
+      }
+
+      return Changed;
+    }
+
+    // Replace the TLS_base_addr instruction I with a copy from
+    // TLSBaseAddrReg, returning the new instruction.
+    MachineInstr *ReplaceTLSBaseAddrCall(MachineInstr *I,
+                                         unsigned TLSBaseAddrReg) {
+      MachineFunction *MF = I->getParent()->getParent();
+      const AArch64TargetMachine *TM =
+          static_cast<const AArch64TargetMachine *>(&MF->getTarget());
+      const AArch64InstrInfo *TII = TM->getInstrInfo();
+
+      // Insert a Copy from TLSBaseAddrReg to x0, which is where the rest of the
+      // code sequence assumes the address will be.
+      MachineInstr *Copy = BuildMI(*I->getParent(), I, I->getDebugLoc(),
+                                   TII->get(TargetOpcode::COPY),
+                                   AArch64::X0)
+        .addReg(TLSBaseAddrReg);
+
+      // Erase the TLS_base_addr instruction.
+      I->eraseFromParent();
+
+      return Copy;
+    }
+
+    // Create a virtal register in *TLSBaseAddrReg, and populate it by
+    // inserting a copy instruction after I. Returns the new instruction.
+    MachineInstr *SetRegister(MachineInstr *I, unsigned *TLSBaseAddrReg) {
+      MachineFunction *MF = I->getParent()->getParent();
+      const AArch64TargetMachine *TM =
+          static_cast<const AArch64TargetMachine *>(&MF->getTarget());
+      const AArch64InstrInfo *TII = TM->getInstrInfo();
+
+      // Create a virtual register for the TLS base address.
+      MachineRegisterInfo &RegInfo = MF->getRegInfo();
+      *TLSBaseAddrReg = RegInfo.createVirtualRegister(&AArch64::GPR64RegClass);
+
+      // Insert a copy from X0 to TLSBaseAddrReg for later.
+      MachineInstr *Next = I->getNextNode();
+      MachineInstr *Copy = BuildMI(*I->getParent(), Next, I->getDebugLoc(),
+                                   TII->get(TargetOpcode::COPY),
+                                   *TLSBaseAddrReg)
+        .addReg(AArch64::X0);
+
+      return Copy;
+    }
+
+    virtual const char *getPassName() const {
+      return "Local Dynamic TLS Access Clean-up";
+    }
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesCFG();
+      AU.addRequired<MachineDominatorTree>();
+      MachineFunctionPass::getAnalysisUsage(AU);
+    }
+  };
+}
+
+char LDTLSCleanup::ID = 0;
+FunctionPass*
+llvm::createAArch64CleanupLocalDynamicTLSPass() { return new LDTLSCleanup(); }