Checkpoint Thumb2 Instr info work. Generalized base code so that it can be shared between ARM and Thumb2. Not yet activated because register information must be generalized first.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75010 91177308-0d34-0410-b5e6-96231b3b80d8

12 files changed, 1414 insertions, 1115 deletions

diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
new file mode 100644
index 0000000000..a1ea692d3b
--- /dev/null
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -0,0 +1,816 @@
+//===- ARMBaseInstrInfo.cpp - ARM Instruction Information -----------*- C++ -*-===//
+//
+//                     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 Base ARM implementation of the TargetInstrInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARMBaseInstrInfo.h"
+#include "ARM.h"
+#include "ARMAddressingModes.h"
+#include "ARMGenInstrInfo.inc"
+#include "ARMMachineFunctionInfo.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/CodeGen/LiveVariables.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+static cl::opt<bool>
+EnableARM3Addr("enable-arm-3-addr-conv", cl::Hidden,
+               cl::desc("Enable ARM 2-addr to 3-addr conv"));
+
+static inline
+const MachineInstrBuilder &AddDefaultPred(const MachineInstrBuilder &MIB) {
+  return MIB.addImm((int64_t)ARMCC::AL).addReg(0);
+}
+
+static inline
+const MachineInstrBuilder &AddDefaultCC(const MachineInstrBuilder &MIB) {
+  return MIB.addReg(0);
+}
+
+ARMBaseInstrInfo::ARMBaseInstrInfo(const ARMSubtarget &STI)
+  : TargetInstrInfoImpl(ARMInsts, array_lengthof(ARMInsts)) {
+}
+
+MachineInstr *
+ARMBaseInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
+                                        MachineBasicBlock::iterator &MBBI,
+                                        LiveVariables *LV) const {
+  if (!EnableARM3Addr)
+    return NULL;
+
+  MachineInstr *MI = MBBI;
+  MachineFunction &MF = *MI->getParent()->getParent();
+  unsigned TSFlags = MI->getDesc().TSFlags;
+  bool isPre = false;
+  switch ((TSFlags & ARMII::IndexModeMask) >> ARMII::IndexModeShift) {
+  default: return NULL;
+  case ARMII::IndexModePre:
+    isPre = true;
+    break;
+  case ARMII::IndexModePost:
+    break;
+  }
+
+  // Try splitting an indexed load/store to an un-indexed one plus an add/sub
+  // operation.
+  unsigned MemOpc = getUnindexedOpcode(MI->getOpcode());
+  if (MemOpc == 0)
+    return NULL;
+
+  MachineInstr *UpdateMI = NULL;
+  MachineInstr *MemMI = NULL;
+  unsigned AddrMode = (TSFlags & ARMII::AddrModeMask);
+  const TargetInstrDesc &TID = MI->getDesc();
+  unsigned NumOps = TID.getNumOperands();
+  bool isLoad = !TID.mayStore();
+  const MachineOperand &WB = isLoad ? MI->getOperand(1) : MI->getOperand(0);
+  const MachineOperand &Base = MI->getOperand(2);
+  const MachineOperand &Offset = MI->getOperand(NumOps-3);
+  unsigned WBReg = WB.getReg();
+  unsigned BaseReg = Base.getReg();
+  unsigned OffReg = Offset.getReg();
+  unsigned OffImm = MI->getOperand(NumOps-2).getImm();
+  ARMCC::CondCodes Pred = (ARMCC::CondCodes)MI->getOperand(NumOps-1).getImm();
+  switch (AddrMode) {
+  default:
+    assert(false && "Unknown indexed op!");
+    return NULL;
+  case ARMII::AddrMode2: {
+    bool isSub = ARM_AM::getAM2Op(OffImm) == ARM_AM::sub;
+    unsigned Amt = ARM_AM::getAM2Offset(OffImm);
+    if (OffReg == 0) {
+      int SOImmVal = ARM_AM::getSOImmVal(Amt);
+      if (SOImmVal == -1)
+        // Can't encode it in a so_imm operand. This transformation will
+        // add more than 1 instruction. Abandon!
+        return NULL;
+      UpdateMI = BuildMI(MF, MI->getDebugLoc(),
+                         get(isSub ? getOpcode(ARMII::SUBri) :
+                             getOpcode(ARMII::ADDri)), WBReg)
+        .addReg(BaseReg).addImm(SOImmVal)
+        .addImm(Pred).addReg(0).addReg(0);
+    } else if (Amt != 0) {
+      ARM_AM::ShiftOpc ShOpc = ARM_AM::getAM2ShiftOpc(OffImm);
+      unsigned SOOpc = ARM_AM::getSORegOpc(ShOpc, Amt);
+      UpdateMI = BuildMI(MF, MI->getDebugLoc(),
+                         get(isSub ? getOpcode(ARMII::SUBrs) :
+                             getOpcode(ARMII::ADDrs)), WBReg)
+        .addReg(BaseReg).addReg(OffReg).addReg(0).addImm(SOOpc)
+        .addImm(Pred).addReg(0).addReg(0);
+    } else
+      UpdateMI = BuildMI(MF, MI->getDebugLoc(),
+                         get(isSub ? getOpcode(ARMII::SUBrr) :
+                             getOpcode(ARMII::ADDrr)), WBReg)
+        .addReg(BaseReg).addReg(OffReg)
+        .addImm(Pred).addReg(0).addReg(0);
+    break;
+  }
+  case ARMII::AddrMode3 : {
+    bool isSub = ARM_AM::getAM3Op(OffImm) == ARM_AM::sub;
+    unsigned Amt = ARM_AM::getAM3Offset(OffImm);
+    if (OffReg == 0)
+      // Immediate is 8-bits. It's guaranteed to fit in a so_imm operand.
+      UpdateMI = BuildMI(MF, MI->getDebugLoc(),
+                         get(isSub ? getOpcode(ARMII::SUBri) : 
+                             getOpcode(ARMII::ADDri)), WBReg)
+        .addReg(BaseReg).addImm(Amt)
+        .addImm(Pred).addReg(0).addReg(0);
+    else
+      UpdateMI = BuildMI(MF, MI->getDebugLoc(),
+                         get(isSub ? getOpcode(ARMII::SUBrr) :
+                             getOpcode(ARMII::ADDrr)), WBReg)
+        .addReg(BaseReg).addReg(OffReg)
+        .addImm(Pred).addReg(0).addReg(0);
+    break;
+  }
+  }
+
+  std::vector<MachineInstr*> NewMIs;
+  if (isPre) {
+    if (isLoad)
+      MemMI = BuildMI(MF, MI->getDebugLoc(),
+                      get(MemOpc), MI->getOperand(0).getReg())
+        .addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
+    else
+      MemMI = BuildMI(MF, MI->getDebugLoc(),
+                      get(MemOpc)).addReg(MI->getOperand(1).getReg())
+        .addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
+    NewMIs.push_back(MemMI);
+    NewMIs.push_back(UpdateMI);
+  } else {
+    if (isLoad)
+      MemMI = BuildMI(MF, MI->getDebugLoc(),
+                      get(MemOpc), MI->getOperand(0).getReg())
+        .addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
+    else
+      MemMI = BuildMI(MF, MI->getDebugLoc(),
+                      get(MemOpc)).addReg(MI->getOperand(1).getReg())
+        .addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
+    if (WB.isDead())
+      UpdateMI->getOperand(0).setIsDead();
+    NewMIs.push_back(UpdateMI);
+    NewMIs.push_back(MemMI);
+  }
+
+  // Transfer LiveVariables states, kill / dead info.
+  if (LV) {
+    for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+      MachineOperand &MO = MI->getOperand(i);
+      if (MO.isReg() && MO.getReg() &&
+          TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
+        unsigned Reg = MO.getReg();
+
+        LiveVariables::VarInfo &VI = LV->getVarInfo(Reg);
+        if (MO.isDef()) {
+          MachineInstr *NewMI = (Reg == WBReg) ? UpdateMI : MemMI;
+          if (MO.isDead())
+            LV->addVirtualRegisterDead(Reg, NewMI);
+        }
+        if (MO.isUse() && MO.isKill()) {
+          for (unsigned j = 0; j < 2; ++j) {
+            // Look at the two new MI's in reverse order.
+            MachineInstr *NewMI = NewMIs[j];
+            if (!NewMI->readsRegister(Reg))
+              continue;
+            LV->addVirtualRegisterKilled(Reg, NewMI);
+            if (VI.removeKill(MI))
+              VI.Kills.push_back(NewMI);
+            break;
+          }
+        }
+      }
+    }
+  }
+
+  MFI->insert(MBBI, NewMIs[1]);
+  MFI->insert(MBBI, NewMIs[0]);
+  return NewMIs[0];
+}
+
+// Branch analysis.
+bool
+ARMBaseInstrInfo::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() || !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 == getOpcode(ARMII::B)) {
+      TBB = LastInst->getOperand(0).getMBB();
+      return false;
+    }
+    if (LastOpc == getOpcode(ARMII::Bcc)) {
+      // Block ends with fall-through condbranch.
+      TBB = LastInst->getOperand(0).getMBB();
+      Cond.push_back(LastInst->getOperand(1));
+      Cond.push_back(LastInst->getOperand(2));
+      return false;
+    }
+    return true;  // Can't handle indirect branch.
+  }
+
+  // Get the instruction before it if it is a terminator.
+  MachineInstr *SecondLastInst = I;
+
+  // 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 ARMII::B and a ARMII::Bcc, handle it.
+  unsigned SecondLastOpc = SecondLastInst->getOpcode();
+  if ((SecondLastOpc == getOpcode(ARMII::Bcc)) && 
+      (LastOpc == getOpcode(ARMII::B))) {
+    TBB =  SecondLastInst->getOperand(0).getMBB();
+    Cond.push_back(SecondLastInst->getOperand(1));
+    Cond.push_back(SecondLastInst->getOperand(2));
+    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 == getOpcode(ARMII::B)) && 
+      (LastOpc == getOpcode(ARMII::B))) {
+    TBB = SecondLastInst->getOperand(0).getMBB();
+    I = LastInst;
+    if (AllowModify)
+      I->eraseFromParent();
+    return false;
+  }
+
+  // ...likewise if it ends with a branch table followed by an unconditional
+  // branch. The branch folder can create these, and we must get rid of them for
+  // correctness of Thumb constant islands.
+  if (((SecondLastOpc == getOpcode(ARMII::BR_JTr)) || 
+       (SecondLastOpc == getOpcode(ARMII::BR_JTm)) ||
+       (SecondLastOpc == getOpcode(ARMII::BR_JTadd))) &&
+      (LastOpc == getOpcode(ARMII::B))) {
+    I = LastInst;
+    if (AllowModify)
+      I->eraseFromParent();
+    return true;
+  }
+
+  // Otherwise, can't handle this.
+  return true;
+}
+
+
+unsigned ARMBaseInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+  int BOpc   = getOpcode(ARMII::B);
+  int BccOpc = getOpcode(ARMII::Bcc);
+
+  MachineBasicBlock::iterator I = MBB.end();
+  if (I == MBB.begin()) return 0;
+  --I;
+  if (I->getOpcode() != BOpc && I->getOpcode() != BccOpc)
+    return 0;
+
+  // Remove the branch.
+  I->eraseFromParent();
+
+  I = MBB.end();
+
+  if (I == MBB.begin()) return 1;
+  --I;
+  if (I->getOpcode() != BccOpc)
+    return 1;
+
+  // Remove the branch.
+  I->eraseFromParent();
+  return 2;
+}
+
+unsigned
+ARMBaseInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
+                               MachineBasicBlock *FBB,
+                             const SmallVectorImpl<MachineOperand> &Cond) const {
+  // FIXME this should probably have a DebugLoc argument
+  DebugLoc dl = DebugLoc::getUnknownLoc();
+  int BOpc   = getOpcode(ARMII::B);
+  int BccOpc = getOpcode(ARMII::Bcc);
+
+  // Shouldn't be a fall through.
+  assert(TBB && "InsertBranch must not be told to insert a fallthrough");
+  assert((Cond.size() == 2 || Cond.size() == 0) &&
+         "ARM branch conditions have two components!");
+
+  if (FBB == 0) {
+    if (Cond.empty()) // Unconditional branch?
+      BuildMI(&MBB, dl, get(BOpc)).addMBB(TBB);
+    else
+      BuildMI(&MBB, dl, get(BccOpc)).addMBB(TBB)
+        .addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
+    return 1;
+  }
+
+  // Two-way conditional branch.
+  BuildMI(&MBB, dl, get(BccOpc)).addMBB(TBB)
+    .addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
+  BuildMI(&MBB, dl, get(BOpc)).addMBB(FBB);
+  return 2;
+}
+
+bool ARMBaseInstrInfo::
+ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
+  ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
+  Cond[0].setImm(ARMCC::getOppositeCondition(CC));
+  return false;
+}
+
+bool ARMBaseInstrInfo::isPredicated(const MachineInstr *MI) const {
+  int PIdx = MI->findFirstPredOperandIdx();
+  return PIdx != -1 && MI->getOperand(PIdx).getImm() != ARMCC::AL;
+}
+
+bool ARMBaseInstrInfo::
+PredicateInstruction(MachineInstr *MI,
+                     const SmallVectorImpl<MachineOperand> &Pred) const {
+  unsigned Opc = MI->getOpcode();
+  if (Opc == getOpcode(ARMII::B)) {
+    MI->setDesc(get(getOpcode(ARMII::Bcc)));
+    MI->addOperand(MachineOperand::CreateImm(Pred[0].getImm()));
+    MI->addOperand(MachineOperand::CreateReg(Pred[1].getReg(), false));
+    return true;
+  }
+
+  int PIdx = MI->findFirstPredOperandIdx();
+  if (PIdx != -1) {
+    MachineOperand &PMO = MI->getOperand(PIdx);
+    PMO.setImm(Pred[0].getImm());
+    MI->getOperand(PIdx+1).setReg(Pred[1].getReg());
+    return true;
+  }
+  return false;
+}
+
+bool ARMBaseInstrInfo::
+SubsumesPredicate(const SmallVectorImpl<MachineOperand> &Pred1,
+                  const SmallVectorImpl<MachineOperand> &Pred2) const {
+  if (Pred1.size() > 2 || Pred2.size() > 2)
+    return false;
+
+  ARMCC::CondCodes CC1 = (ARMCC::CondCodes)Pred1[0].getImm();
+  ARMCC::CondCodes CC2 = (ARMCC::CondCodes)Pred2[0].getImm();
+  if (CC1 == CC2)
+    return true;
+
+  switch (CC1) {
+  default:
+    return false;
+  case ARMCC::AL:
+    return true;
+  case ARMCC::HS:
+    return CC2 == ARMCC::HI;
+  case ARMCC::LS:
+    return CC2 == ARMCC::LO || CC2 == ARMCC::EQ;
+  case ARMCC::GE:
+    return CC2 == ARMCC::GT;
+  case ARMCC::LE:
+    return CC2 == ARMCC::LT;
+  }
+}
+
+bool ARMBaseInstrInfo::DefinesPredicate(MachineInstr *MI,
+                                    std::vector<MachineOperand> &Pred) const {
+  const TargetInstrDesc &TID = MI->getDesc();
+  if (!TID.getImplicitDefs() && !TID.hasOptionalDef())
+    return false;
+
+  bool Found = false;
+  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+    const MachineOperand &MO = MI->getOperand(i);
+    if (MO.isReg() && MO.getReg() == ARM::CPSR) {
+      Pred.push_back(MO);
+      Found = true;
+    }
+  }
+
+  return Found;
+}
+
+
+/// FIXME: Works around a gcc miscompilation with -fstrict-aliasing
+static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
+                                unsigned JTI) DISABLE_INLINE;
+static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
+                                unsigned JTI) {
+  return JT[JTI].MBBs.size();
+}
+
+/// GetInstSize - Return the size of the specified MachineInstr.
+///
+unsigned ARMBaseInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
+  const MachineBasicBlock &MBB = *MI->getParent();
+  const MachineFunction *MF = MBB.getParent();
+  const TargetAsmInfo *TAI = MF->getTarget().getTargetAsmInfo();
+
+  // Basic size info comes from the TSFlags field.
+  const TargetInstrDesc &TID = MI->getDesc();
+  unsigned TSFlags = TID.TSFlags;
+
+  switch ((TSFlags & ARMII::SizeMask) >> ARMII::SizeShift) {
+  default: {
+    // If this machine instr is an inline asm, measure it.
+    if (MI->getOpcode() == ARM::INLINEASM)
+      return TAI->getInlineAsmLength(MI->getOperand(0).getSymbolName());
+    if (MI->isLabel())
+      return 0;
+    switch (MI->getOpcode()) {
+    default:
+      assert(0 && "Unknown or unset size field for instr!");
+      break;
+    case TargetInstrInfo::IMPLICIT_DEF:
+    case TargetInstrInfo::DECLARE:
+    case TargetInstrInfo::DBG_LABEL:
+    case TargetInstrInfo::EH_LABEL:
+      return 0;
+    }
+    break;
+  }
+  case ARMII::Size8Bytes: return 8;          // Arm instruction x 2.
+  case ARMII::Size4Bytes: return 4;          // Arm instruction.
+  case ARMII::Size2Bytes: return 2;          // Thumb instruction.
+  case ARMII::SizeSpecial: {
+    switch (MI->getOpcode()) {
+    case ARM::CONSTPOOL_ENTRY:
+      // If this machine instr is a constant pool entry, its size is recorded as
+      // operand #2.
+      return MI->getOperand(2).getImm();
+    case ARM::Int_eh_sjlj_setjmp: return 12;
+    case ARM::BR_JTr:
+    case ARM::BR_JTm:
+    case ARM::BR_JTadd:
+    case ARM::t2BR_JTr:
+    case ARM::t2BR_JTm:
+    case ARM::t2BR_JTadd:
+    case ARM::tBR_JTr: {
+      // These are jumptable branches, i.e. a branch followed by an inlined
+      // jumptable. The size is 4 + 4 * number of entries.
+      unsigned NumOps = TID.getNumOperands();
+      MachineOperand JTOP =
+        MI->getOperand(NumOps - (TID.isPredicable() ? 3 : 2));
+      unsigned JTI = JTOP.getIndex();
+      const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
+      const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
+      assert(JTI < JT.size());
+      // Thumb instructions are 2 byte aligned, but JT entries are 4 byte
+      // 4 aligned. The assembler / linker may add 2 byte padding just before
+      // the JT entries.  The size does not include this padding; the
+      // constant islands pass does separate bookkeeping for it.
+      // FIXME: If we know the size of the function is less than (1 << 16) *2
+      // bytes, we can use 16-bit entries instead. Then there won't be an
+      // alignment issue.
+      return getNumJTEntries(JT, JTI) * 4 +
+        ((MI->getOpcode()==ARM::tBR_JTr) ? 2 : 4);
+    }
+    default:
+      // Otherwise, pseudo-instruction sizes are zero.
+      return 0;
+    }
+  }
+  }
+  return 0; // Not reached
+}
+
+/// Return true if the instruction is a register to register move and
+/// leave the source and dest operands in the passed parameters.
+///
+bool
+ARMBaseInstrInfo::isMoveInstr(const MachineInstr &MI,
+                              unsigned &SrcReg, unsigned &DstReg,
+                              unsigned& SrcSubIdx, unsigned& DstSubIdx) const {
+  SrcSubIdx = DstSubIdx = 0; // No sub-registers.
+
+  unsigned oc = MI.getOpcode();
+  if ((oc == getOpcode(ARMII::FCPYS)) ||
+      (oc == getOpcode(ARMII::FCPYD)) ||
+      (oc == getOpcode(ARMII::VMOVD)) ||
+      (oc == getOpcode(ARMII::VMOVQ))) {
+    SrcReg = MI.getOperand(1).getReg();
+    DstReg = MI.getOperand(0).getReg();
+    return true;
+  }
+  else if (oc == getOpcode(ARMII::MOVr)) {
+    assert(MI.getDesc().getNumOperands() >= 2 &&
+           MI.getOperand(0).isReg() &&
+           MI.getOperand(1).isReg() &&
+           "Invalid ARM MOV instruction");
+    SrcReg = MI.getOperand(1).getReg();
+    DstReg = MI.getOperand(0).getReg();
+    return true;
+  }
+
+  return false;
+}
+
+unsigned 
+ARMBaseInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
+                                      int &FrameIndex) const {
+  unsigned oc = MI->getOpcode();
+  if (oc == getOpcode(ARMII::LDR)) {
+    if (MI->getOperand(1).isFI() &&
+        MI->getOperand(2).isReg() &&
+        MI->getOperand(3).isImm() &&
+        MI->getOperand(2).getReg() == 0 &&
+        MI->getOperand(3).getImm() == 0) {
+      FrameIndex = MI->getOperand(1).getIndex();
+      return MI->getOperand(0).getReg();
+    }
+  }
+  else if ((oc == getOpcode(ARMII::FLDD)) ||
+           (oc == getOpcode(ARMII::FLDS))) {
+    if (MI->getOperand(1).isFI() &&
+        MI->getOperand(2).isImm() &&
+        MI->getOperand(2).getImm() == 0) {
+      FrameIndex = MI->getOperand(1).getIndex();
+      return MI->getOperand(0).getReg();
+    }
+  }
+
+  return 0;
+}
+
+unsigned
+ARMBaseInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
+                                     int &FrameIndex) const {
+  unsigned oc = MI->getOpcode();
+  if (oc == getOpcode(ARMII::STR)) {
+    if (MI->getOperand(1).isFI() &&
+        MI->getOperand(2).isReg() &&
+        MI->getOperand(3).isImm() &&
+        MI->getOperand(2).getReg() == 0 &&
+        MI->getOperand(3).getImm() == 0) {
+      FrameIndex = MI->getOperand(1).getIndex();
+      return MI->getOperand(0).getReg();
+    }
+  }
+  else if ((oc == getOpcode(ARMII::FSTD)) ||
+           (oc == getOpcode(ARMII::FSTS))) {
+    if (MI->getOperand(1).isFI() &&
+        MI->getOperand(2).isImm() &&
+        MI->getOperand(2).getImm() == 0) {
+      FrameIndex = MI->getOperand(1).getIndex();
+      return MI->getOperand(0).getReg();
+    }
+  }
+
+  return 0;
+}
+
+bool
+ARMBaseInstrInfo::copyRegToReg(MachineBasicBlock &MBB,
+                               MachineBasicBlock::iterator I,
+                               unsigned DestReg, unsigned SrcReg,
+                               const TargetRegisterClass *DestRC,
+                               const TargetRegisterClass *SrcRC) const {
+  DebugLoc DL = DebugLoc::getUnknownLoc();
+  if (I != MBB.end()) DL = I->getDebugLoc();
+
+  if (DestRC != SrcRC) {
+    // Not yet supported!
+    return false;
+  }
+
+  if (DestRC == ARM::GPRRegisterClass)
+    AddDefaultCC(AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::MOVr)), DestReg)
+                                .addReg(SrcReg)));
+  else if (DestRC == ARM::SPRRegisterClass)
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::FCPYS)), DestReg)
+                   .addReg(SrcReg));
+  else if (DestRC == ARM::DPRRegisterClass)
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::FCPYD)), DestReg)
+                   .addReg(SrcReg));
+  else if (DestRC == ARM::QPRRegisterClass)
+    BuildMI(MBB, I, DL, get(getOpcode(ARMII::VMOVQ)), DestReg).addReg(SrcReg);
+  else
+    return false;
+
+  return true;
+}
+
+void ARMBaseInstrInfo::
+storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
+                    unsigned SrcReg, bool isKill, int FI,
+                    const TargetRegisterClass *RC) const {
+  DebugLoc DL = DebugLoc::getUnknownLoc();
+  if (I != MBB.end()) DL = I->getDebugLoc();
+
+  if (RC == ARM::GPRRegisterClass) {
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::STR)))
+                   .addReg(SrcReg, getKillRegState(isKill))
+                   .addFrameIndex(FI).addReg(0).addImm(0));
+  } else if (RC == ARM::DPRRegisterClass) {
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::FSTD)))
+                   .addReg(SrcReg, getKillRegState(isKill))
+                   .addFrameIndex(FI).addImm(0));
+  } else {
+    assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::FSTS)))
+                   .addReg(SrcReg, getKillRegState(isKill))
+                   .addFrameIndex(FI).addImm(0));
+  }
+}
+
+void 
+ARMBaseInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                 bool isKill,
+                                 SmallVectorImpl<MachineOperand> &Addr,
+                                 const TargetRegisterClass *RC,
+                                 SmallVectorImpl<MachineInstr*> &NewMIs) const{
+  DebugLoc DL = DebugLoc::getUnknownLoc();
+  unsigned Opc = 0;
+  if (RC == ARM::GPRRegisterClass) {
+    Opc = getOpcode(ARMII::STR);
+  } else if (RC == ARM::DPRRegisterClass) {
+    Opc = getOpcode(ARMII::FSTD);
+  } else {
+    assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
+    Opc = getOpcode(ARMII::FSTS);
+  }
+
+  MachineInstrBuilder MIB =
+    BuildMI(MF, DL, get(Opc)).addReg(SrcReg, getKillRegState(isKill));
+  for (unsigned i = 0, e = Addr.size(); i != e; ++i)
+    MIB.addOperand(Addr[i]);
+  AddDefaultPred(MIB);
+  NewMIs.push_back(MIB);
+  return;
+}
+
+void ARMBaseInstrInfo::
+loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
+                     unsigned DestReg, int FI,
+                     const TargetRegisterClass *RC) const {
+  DebugLoc DL = DebugLoc::getUnknownLoc();
+  if (I != MBB.end()) DL = I->getDebugLoc();
+
+  if (RC == ARM::GPRRegisterClass) {
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::LDR)), DestReg)
+                   .addFrameIndex(FI).addReg(0).addImm(0));
+  } else if (RC == ARM::DPRRegisterClass) {
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::FLDD)), DestReg)
+                   .addFrameIndex(FI).addImm(0));
+  } else {
+    assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
+    AddDefaultPred(BuildMI(MBB, I, DL, get(getOpcode(ARMII::FLDS)), DestReg)
+                   .addFrameIndex(FI).addImm(0));
+  }
+}
+
+void ARMBaseInstrInfo::
+loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
+                SmallVectorImpl<MachineOperand> &Addr,
+                const TargetRegisterClass *RC,
+                SmallVectorImpl<MachineInstr*> &NewMIs) const {
+  DebugLoc DL = DebugLoc::getUnknownLoc();
+  unsigned Opc = 0;
+  if (RC == ARM::GPRRegisterClass) {
+    Opc = getOpcode(ARMII::LDR);
+  } else if (RC == ARM::DPRRegisterClass) {
+      Opc = getOpcode(ARMII::FLDD);
+  } else {
+    assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
+    Opc = getOpcode(ARMII::FLDS);
+  }
+
+  MachineInstrBuilder MIB =  BuildMI(MF, DL, get(Opc), DestReg);
+  for (unsigned i = 0, e = Addr.size(); i != e; ++i)
+    MIB.addOperand(Addr[i]);
+  AddDefaultPred(MIB);
+  NewMIs.push_back(MIB);
+  return;
+}
+
+MachineInstr *ARMBaseInstrInfo::
+foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
+                      const SmallVectorImpl<unsigned> &Ops, int FI) const {
+  if (Ops.size() != 1) return NULL;
+
+  unsigned OpNum = Ops[0];
+  unsigned Opc = MI->getOpcode();
+  MachineInstr *NewMI = NULL;
+  if (Opc == getOpcode(ARMII::MOVr)) {
+    // If it is updating CPSR, then it cannot be folded.
+    if (MI->getOperand(4).getReg() != ARM::CPSR) {
+      unsigned Pred = MI->getOperand(2).getImm();
+      unsigned PredReg = MI->getOperand(3).getReg();
+      if (OpNum == 0) { // move -> store
+        unsigned SrcReg = MI->getOperand(1).getReg();
+        bool isKill = MI->getOperand(1).isKill();
+        bool isUndef = MI->getOperand(1).isUndef();
+        NewMI = BuildMI(MF, MI->getDebugLoc(), get(getOpcode(ARMII::STR)))
+          .addReg(SrcReg, getKillRegState(isKill) | getUndefRegState(isUndef))
+          .addFrameIndex(FI).addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
+      } else {          // move -> load
+        unsigned DstReg = MI->getOperand(0).getReg();
+        bool isDead = MI->getOperand(0).isDead();
+        bool isUndef = MI->getOperand(0).isUndef();
+        NewMI = BuildMI(MF, MI->getDebugLoc(), get(getOpcode(ARMII::LDR)))
+          .addReg(DstReg,
+                  RegState::Define |
+                  getDeadRegState(isDead) |
+                  getUndefRegState(isUndef))
+          .addFrameIndex(FI).addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
+      }
+    }
+  }
+  else if (Opc == getOpcode(ARMII::FCPYS)) {
+    unsigned Pred = MI->getOperand(2).getImm();
+    unsigned PredReg = MI->getOperand(3).getReg();
+    if (OpNum == 0) { // move -> store
+      unsigned SrcReg = MI->getOperand(1).getReg();
+      bool isKill = MI->getOperand(1).isKill();
+      bool isUndef = MI->getOperand(1).isUndef();
+      NewMI = BuildMI(MF, MI->getDebugLoc(), get(getOpcode(ARMII::FSTS)))
+        .addReg(SrcReg, getKillRegState(isKill) | getUndefRegState(isUndef))
+        .addFrameIndex(FI)
+        .addImm(0).addImm(Pred).addReg(PredReg);
+    } else {          // move -> load
+      unsigned DstReg = MI->getOperand(0).getReg();
+      bool isDead = MI->getOperand(0).isDead();
+      bool isUndef = MI->getOperand(0).isUndef();
+      NewMI = BuildMI(MF, MI->getDebugLoc(), get(getOpcode(ARMII::FLDS)))
+        .addReg(DstReg,
+                RegState::Define |
+                getDeadRegState(isDead) |
+                getUndefRegState(isUndef))
+        .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
+    }
+  }
+  else if (Opc == getOpcode(ARMII::FCPYD)) {
+    unsigned Pred = MI->getOperand(2).getImm();
+    unsigned PredReg = MI->getOperand(3).getReg();
+    if (OpNum == 0) { // move -> store
+      unsigned SrcReg = MI->getOperand(1).getReg();
+      bool isKill = MI->getOperand(1).isKill();
+      bool isUndef = MI->getOperand(1).isUndef();
+      NewMI = BuildMI(MF, MI->getDebugLoc(), get(getOpcode(ARMII::FSTD)))
+        .addReg(SrcReg, getKillRegState(isKill) | getUndefRegState(isUndef))
+        .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
+    } else {          // move -> load
+      unsigned DstReg = MI->getOperand(0).getReg();
+      bool isDead = MI->getOperand(0).isDead();
+      bool isUndef = MI->getOperand(0).isUndef();
+      NewMI = BuildMI(MF, MI->getDebugLoc(), get(getOpcode(ARMII::FLDD)))
+        .addReg(DstReg,
+                RegState::Define |
+                getDeadRegState(isDead) |
+                getUndefRegState(isUndef))
+        .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
+    }
+  }
+
+  return NewMI;
+}
+
+MachineInstr* 
+ARMBaseInstrInfo::foldMemoryOperandImpl(MachineFunction &MF,
+                                        MachineInstr* MI,
+                                        const SmallVectorImpl<unsigned> &Ops,
+                                        MachineInstr* LoadMI) const {
+  return 0;
+}
+
+bool
+ARMBaseInstrInfo::canFoldMemoryOperand(const MachineInstr *MI,
+                                       const SmallVectorImpl<unsigned> &Ops) const {
+  if (Ops.size() != 1) return false;
+
+  unsigned Opc = MI->getOpcode();
+  if (Opc == getOpcode(ARMII::MOVr)) {
+    // If it is updating CPSR, then it cannot be folded.
+    return MI->getOperand(4).getReg() != ARM::CPSR;
+  }
+  else if ((Opc == getOpcode(ARMII::FCPYS)) ||
+           (Opc == getOpcode(ARMII::FCPYD))) {
+    return true;
+  }
+  else if ((Opc == getOpcode(ARMII::VMOVD)) ||
+           (Opc == getOpcode(ARMII::VMOVQ))) {
+    return false; // FIXME
+  }
+
+  return false;
+}
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.h b/lib/Target/ARM/ARMBaseInstrInfo.h
new file mode 100644
index 0000000000..f263967dfb
--- /dev/null
+++ b/lib/Target/ARM/ARMBaseInstrInfo.h
@@ -0,0 +1,298 @@
+//===- ARMBaseInstrInfo.h - ARM Base Instruction Information -------------*- C++ -*-===//
+//
+//                     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 Base ARM implementation of the TargetInstrInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef ARMBASEINSTRUCTIONINFO_H
+#define ARMBASEINSTRUCTIONINFO_H
+
+#include "llvm/Target/TargetInstrInfo.h"
+#include "ARMRegisterInfo.h"
+#include "ARM.h"
+
+namespace llvm {
+  class ARMSubtarget;
+
+/// ARMII - This namespace holds all of the target specific flags that
+/// instruction info tracks.
+///
+namespace ARMII {
+  enum {
+    //===------------------------------------------------------------------===//
+    // Instruction Flags.
+
+    //===------------------------------------------------------------------===//
+    // This four-bit field describes the addressing mode used.
+
+    AddrModeMask  = 0xf,
+    AddrModeNone    = 0,
+    AddrMode1       = 1,
+    AddrMode2       = 2,
+    AddrMode3       = 3,
+    AddrMode4       = 4,
+    AddrMode5       = 5,
+    AddrMode6       = 6,
+    AddrModeT1_1    = 7,
+    AddrModeT1_2    = 8,
+    AddrModeT1_4    = 9,
+    AddrModeT1_s    = 10, // i8 * 4 for pc and sp relative data
+    AddrModeT2_i12  = 11,
+    AddrModeT2_i8   = 12,
+    AddrModeT2_so   = 13,
+    AddrModeT2_pc   = 14, // +/- i12 for pc relative data
+    AddrModeT2_i8s4 = 15, // i8 * 4
+
+    // Size* - Flags to keep track of the size of an instruction.
+    SizeShift     = 4,
+    SizeMask      = 7 << SizeShift,
+    SizeSpecial   = 1,   // 0 byte pseudo or special case.
+    Size8Bytes    = 2,
+    Size4Bytes    = 3,
+    Size2Bytes    = 4,
+
+    // IndexMode - Unindex, pre-indexed, or post-indexed. Only valid for load
+    // and store ops
+    IndexModeShift = 7,
+    IndexModeMask  = 3 << IndexModeShift,