Hexagon backend support

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146412 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1503 insertions, 0 deletions

diff --git a/lib/Target/Hexagon/HexagonISelLowering.cpp b/lib/Target/Hexagon/HexagonISelLowering.cpp
new file mode 100644
index 0000000000..8d2d3fd8f6
--- /dev/null
+++ b/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -0,0 +1,1503 @@
+//===-- HexagonISelLowering.cpp - Hexagon DAG Lowering Implementation -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the interfaces that Hexagon uses to lower LLVM code
+// into a selection DAG.
+//
+//===----------------------------------------------------------------------===//
+
+#include "HexagonISelLowering.h"
+#include "HexagonTargetMachine.h"
+#include "HexagonMachineFunctionInfo.h"
+#include "HexagonTargetObjectFile.h"
+#include "HexagonSubtarget.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/InlineAsm.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/GlobalAlias.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/CallingConv.h"
+#include "llvm/CodeGen/CallingConvLower.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/SelectionDAGISel.h"
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "HexagonMachineFunctionInfo.h"
+#include "llvm/Support/CommandLine.h"
+
+const unsigned Hexagon_MAX_RET_SIZE = 64;
+using namespace llvm;
+
+static cl::opt<bool>
+EmitJumpTables("hexagon-emit-jump-tables", cl::init(true), cl::Hidden,
+               cl::desc("Control jump table emission on Hexagon target"));
+
+int NumNamedVarArgParams = -1;
+
+// Implement calling convention for Hexagon.
+static bool
+CC_Hexagon(unsigned ValNo, MVT ValVT,
+           MVT LocVT, CCValAssign::LocInfo LocInfo,
+           ISD::ArgFlagsTy ArgFlags, CCState &State);
+
+static bool
+CC_Hexagon32(unsigned ValNo, MVT ValVT,
+             MVT LocVT, CCValAssign::LocInfo LocInfo,
+             ISD::ArgFlagsTy ArgFlags, CCState &State);
+
+static bool
+CC_Hexagon64(unsigned ValNo, MVT ValVT,
+             MVT LocVT, CCValAssign::LocInfo LocInfo,
+             ISD::ArgFlagsTy ArgFlags, CCState &State);
+
+static bool
+RetCC_Hexagon(unsigned ValNo, MVT ValVT,
+              MVT LocVT, CCValAssign::LocInfo LocInfo,
+              ISD::ArgFlagsTy ArgFlags, CCState &State);
+
+static bool
+RetCC_Hexagon32(unsigned ValNo, MVT ValVT,
+                MVT LocVT, CCValAssign::LocInfo LocInfo,
+                ISD::ArgFlagsTy ArgFlags, CCState &State);
+
+static bool
+RetCC_Hexagon64(unsigned ValNo, MVT ValVT,
+                MVT LocVT, CCValAssign::LocInfo LocInfo,
+                ISD::ArgFlagsTy ArgFlags, CCState &State);
+
+static bool
+CC_Hexagon_VarArg (unsigned ValNo, MVT ValVT,
+            MVT LocVT, CCValAssign::LocInfo LocInfo,
+            ISD::ArgFlagsTy ArgFlags, CCState &State) {
+
+  // NumNamedVarArgParams can not be zero for a VarArg function.
+  assert ( (NumNamedVarArgParams > 0) &&
+           "NumNamedVarArgParams is not bigger than zero.");
+
+  if ( (int)ValNo < NumNamedVarArgParams ) {
+    // Deal with named arguments.
+    return CC_Hexagon(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State);
+  }
+
+  // Deal with un-named arguments.
+  unsigned ofst;
+  if (ArgFlags.isByVal()) {
+    // If pass-by-value, the size allocated on stack is decided
+    // by ArgFlags.getByValSize(), not by the size of LocVT.
+    assert ((ArgFlags.getByValSize() > 8) &&
+            "ByValSize must be bigger than 8 bytes");
+    ofst = State.AllocateStack(ArgFlags.getByValSize(), 4);
+    State.addLoc(CCValAssign::getMem(ValNo, ValVT, ofst, LocVT, LocInfo));
+    return false;
+  }
+  if (LocVT == MVT::i32) {
+    ofst = State.AllocateStack(4, 4);
+    State.addLoc(CCValAssign::getMem(ValNo, ValVT, ofst, LocVT, LocInfo));
+    return false;
+  }
+  if (LocVT == MVT::i64) {
+    ofst = State.AllocateStack(8, 8);
+    State.addLoc(CCValAssign::getMem(ValNo, ValVT, ofst, LocVT, LocInfo));
+    return false;
+  }
+  llvm_unreachable(0);
+
+  return true;
+}
+
+
+static bool
+CC_Hexagon (unsigned ValNo, MVT ValVT,
+            MVT LocVT, CCValAssign::LocInfo LocInfo,
+            ISD::ArgFlagsTy ArgFlags, CCState &State) {
+
+  if (ArgFlags.isByVal()) {
+    // Passed on stack.
+    assert ((ArgFlags.getByValSize() > 8) &&
+            "ByValSize must be bigger than 8 bytes");
+    unsigned Offset = State.AllocateStack(ArgFlags.getByValSize(), 4);
+    State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
+    return false;
+  }
+
+  if (LocVT == MVT::i1 || LocVT == MVT::i8 || LocVT == MVT::i16) {
+    LocVT = MVT::i32;
+    ValVT = MVT::i32;
+    if (ArgFlags.isSExt())
+      LocInfo = CCValAssign::SExt;
+    else if (ArgFlags.isZExt())
+      LocInfo = CCValAssign::ZExt;
+    else
+      LocInfo = CCValAssign::AExt;
+  }
+
+  if (LocVT == MVT::i32) {
+    if (!CC_Hexagon32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))
+      return false;
+  }
+
+  if (LocVT == MVT::i64) {
+    if (!CC_Hexagon64(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))
+      return false;
+  }
+
+  return true;  // CC didn't match.
+}
+
+
+static bool CC_Hexagon32(unsigned ValNo, MVT ValVT,
+                         MVT LocVT, CCValAssign::LocInfo LocInfo,
+                         ISD::ArgFlagsTy ArgFlags, CCState &State) {
+
+  static const unsigned RegList[] = {
+    Hexagon::R0, Hexagon::R1, Hexagon::R2, Hexagon::R3, Hexagon::R4,
+    Hexagon::R5
+  };
+  if (unsigned Reg = State.AllocateReg(RegList, 6)) {
+    State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+    return false;
+  }
+
+  unsigned Offset = State.AllocateStack(4, 4);
+  State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
+  return false;
+}
+
+static bool CC_Hexagon64(unsigned ValNo, MVT ValVT,
+                         MVT LocVT, CCValAssign::LocInfo LocInfo,
+                         ISD::ArgFlagsTy ArgFlags, CCState &State) {
+
+  if (unsigned Reg = State.AllocateReg(Hexagon::D0)) {
+    State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+    return false;
+  }
+
+  static const unsigned RegList1[] = {
+    Hexagon::D1, Hexagon::D2
+  };
+  static const unsigned RegList2[] = {
+    Hexagon::R1, Hexagon::R3
+  };
+  if (unsigned Reg = State.AllocateReg(RegList1, RegList2, 2)) {
+    State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+    return false;
+  }
+
+  unsigned Offset = State.AllocateStack(8, 8, Hexagon::D2);
+  State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
+  return false;
+}
+
+static bool RetCC_Hexagon(unsigned ValNo, MVT ValVT,
+                          MVT LocVT, CCValAssign::LocInfo LocInfo,
+                          ISD::ArgFlagsTy ArgFlags, CCState &State) {
+
+
+  if (LocVT == MVT::i1 ||
+      LocVT == MVT::i8 ||
+      LocVT == MVT::i16) {
+    LocVT = MVT::i32;
+    ValVT = MVT::i32;
+    if (ArgFlags.isSExt())
+      LocInfo = CCValAssign::SExt;
+    else if (ArgFlags.isZExt())
+      LocInfo = CCValAssign::ZExt;
+    else
+      LocInfo = CCValAssign::AExt;
+  }
+
+  if (LocVT == MVT::i32) {
+    if (!RetCC_Hexagon32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))
+    return false;
+  }
+
+  if (LocVT == MVT::i64) {
+    if (!RetCC_Hexagon64(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))
+    return false;
+  }
+
+  return true;  // CC didn't match.
+}
+
+static bool RetCC_Hexagon32(unsigned ValNo, MVT ValVT,
+                            MVT LocVT, CCValAssign::LocInfo LocInfo,
+                            ISD::ArgFlagsTy ArgFlags, CCState &State) {
+
+  if (LocVT == MVT::i32) {
+    if (unsigned Reg = State.AllocateReg(Hexagon::R0)) {
+      State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+      return false;
+    }
+  }
+
+  unsigned Offset = State.AllocateStack(4, 4);
+  State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
+  return false;
+}
+
+static bool RetCC_Hexagon64(unsigned ValNo, MVT ValVT,
+                            MVT LocVT, CCValAssign::LocInfo LocInfo,
+                            ISD::ArgFlagsTy ArgFlags, CCState &State) {
+  if (LocVT == MVT::i64) {
+    if (unsigned Reg = State.AllocateReg(Hexagon::D0)) {
+      State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+      return false;
+    }
+  }
+
+  unsigned Offset = State.AllocateStack(8, 8);
+  State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
+  return false;
+}
+
+SDValue
+HexagonTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG)
+const {
+  return SDValue();
+}
+
+/// CreateCopyOfByValArgument - Make a copy of an aggregate at address specified
+/// by "Src" to address "Dst" of size "Size".  Alignment information is
+/// specified by the specific parameter attribute. The copy will be passed as
+/// a byval function parameter.  Sometimes what we are copying is the end of a
+/// larger object, the part that does not fit in registers.
+static SDValue
+CreateCopyOfByValArgument(SDValue Src, SDValue Dst, SDValue Chain,
+                          ISD::ArgFlagsTy Flags, SelectionDAG &DAG,
+                          DebugLoc dl) {
+
+  SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), MVT::i32);
+  return DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode, Flags.getByValAlign(),
+                       /*isVolatile=*/false, /*AlwaysInline=*/false,
+                       MachinePointerInfo(), MachinePointerInfo());
+}
+
+
+// LowerReturn - Lower ISD::RET. If a struct is larger than 8 bytes and is
+// passed by value, the function prototype is modified to return void and
+// the value is stored in memory pointed by a pointer passed by caller.
+SDValue
+HexagonTargetLowering::LowerReturn(SDValue Chain,
+                                   CallingConv::ID CallConv, bool isVarArg,
+                                   const SmallVectorImpl<ISD::OutputArg> &Outs,
+                                   const SmallVectorImpl<SDValue> &OutVals,
+                                   DebugLoc dl, SelectionDAG &DAG) const {
+
+  // CCValAssign - represent the assignment of the return value to locations.
+  SmallVector<CCValAssign, 16> RVLocs;
+
+  // CCState - Info about the registers and stack slot.
+  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+		 getTargetMachine(), RVLocs, *DAG.getContext());
+
+  // Analyze return values of ISD::RET
+  CCInfo.AnalyzeReturn(Outs, RetCC_Hexagon);
+
+  SDValue StackPtr = DAG.getRegister(TM.getRegisterInfo()->getStackRegister(),
+                                     MVT::i32);
+
+  // If this is the first return lowered for this function, add the regs to the
+  // liveout set for the function.
+  if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
+    for (unsigned i = 0; i != RVLocs.size(); ++i)
+      if (RVLocs[i].isRegLoc())
+        DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
+  }
+
+  SDValue Flag;
+  // Copy the result values into the output registers.
+  for (unsigned i = 0; i != RVLocs.size(); ++i) {
+    CCValAssign &VA = RVLocs[i];
+    SDValue Ret = OutVals[i];
+    ISD::ArgFlagsTy Flags = Outs[i].Flags;
+
+    Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), OutVals[i], Flag);
+
+    // Guarantee that all emitted copies are stuck together with flags.
+    Flag = Chain.getValue(1);
+  }
+
+  if (Flag.getNode())
+    return DAG.getNode(HexagonISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
+
+  return DAG.getNode(HexagonISD::RET_FLAG, dl, MVT::Other, Chain);
+}
+
+
+
+
+/// LowerCallResult - Lower the result values of an ISD::CALL into the
+/// appropriate copies out of appropriate physical registers.  This assumes that
+/// Chain/InFlag are the input chain/flag to use, and that TheCall is the call
+/// being lowered. Returns a SDNode with the same number of values as the
+/// ISD::CALL.
+SDValue
+HexagonTargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag,
+                                       CallingConv::ID CallConv, bool isVarArg,
+                                       const
+                                       SmallVectorImpl<ISD::InputArg> &Ins,
+                                       DebugLoc dl, SelectionDAG &DAG,
+                                       SmallVectorImpl<SDValue> &InVals,
+                                       const SmallVectorImpl<SDValue> &OutVals,
+                                       SDValue Callee) const {
+
+  // Assign locations to each value returned by this call.
+  SmallVector<CCValAssign, 16> RVLocs;
+
+  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+		 getTargetMachine(), RVLocs, *DAG.getContext());
+
+  CCInfo.AnalyzeCallResult(Ins, RetCC_Hexagon);
+
+  // Copy all of the result registers out of their specified physreg.
+  for (unsigned i = 0; i != RVLocs.size(); ++i) {
+    Chain = DAG.getCopyFromReg(Chain, dl,
+                               RVLocs[i].getLocReg(),
+                               RVLocs[i].getValVT(), InFlag).getValue(1);
+    InFlag = Chain.getValue(2);
+    InVals.push_back(Chain.getValue(0));
+  }
+
+  return Chain;
+}
+
+/// LowerCall - Functions arguments are copied from virtual regs to
+/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
+SDValue
+HexagonTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
+                                 CallingConv::ID CallConv, bool isVarArg,
+                                 bool &isTailCall,
+                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
+                                 const SmallVectorImpl<SDValue> &OutVals,
+                                 const SmallVectorImpl<ISD::InputArg> &Ins,
+                                 DebugLoc dl, SelectionDAG &DAG,
+                                 SmallVectorImpl<SDValue> &InVals) const {
+
+  bool IsStructRet    = (Outs.empty()) ? false : Outs[0].Flags.isSRet();
+
+  // Analyze operands of the call, assigning locations to each operand.
+  SmallVector<CCValAssign, 16> ArgLocs;
+  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+		 getTargetMachine(), ArgLocs, *DAG.getContext());
+
+  // Check for varargs.
+  NumNamedVarArgParams = -1;
+  if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Callee))
+  {
+    const Function* CalleeFn = NULL;
+    Callee = DAG.getTargetGlobalAddress(GA->getGlobal(), dl, MVT::i32);
+    if ((CalleeFn = dyn_cast<Function>(GA->getGlobal())))
+    {
+      // If a function has zero args and is a vararg function, that's
+      // disallowed so it must be an undeclared function.  Do not assume
+      // varargs if the callee is undefined.
+      if (CalleeFn->isVarArg() &&
+          CalleeFn->getFunctionType()->getNumParams() != 0) {
+        NumNamedVarArgParams = CalleeFn->getFunctionType()->getNumParams();
+      }
+    }
+  }
+
+  if (NumNamedVarArgParams > 0)
+    CCInfo.AnalyzeCallOperands(Outs, CC_Hexagon_VarArg);
+  else
+    CCInfo.AnalyzeCallOperands(Outs, CC_Hexagon);
+
+
+  if(isTailCall) {
+    bool StructAttrFlag =
+      DAG.getMachineFunction().getFunction()->hasStructRetAttr();
+    isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv,
+                                                   isVarArg, IsStructRet,
+                                                   StructAttrFlag,
+                                                   Outs, OutVals, Ins, DAG);
+    for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i){
+      CCValAssign &VA = ArgLocs[i];
+      if (VA.isMemLoc()) {
+        isTailCall = false;
+        break;
+      }
+    }
+    if (isTailCall) {
+      DEBUG(dbgs () << "Eligible for Tail Call\n");
+    } else {
+      DEBUG(dbgs () <<
+            "Argument must be passed on stack. Not eligible for Tail Call\n");
+    }
+  }
+  // Get a count of how many bytes are to be pushed on the stack.
+  unsigned NumBytes = CCInfo.getNextStackOffset();
+  SmallVector<std::pair<unsigned, SDValue>, 16> RegsToPass;
+  SmallVector<SDValue, 8> MemOpChains;
+
+  SDValue StackPtr =
+    DAG.getCopyFromReg(Chain, dl, TM.getRegisterInfo()->getStackRegister(),
+                       getPointerTy());
+
+  // Walk the register/memloc assignments, inserting copies/loads.
+  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
+    CCValAssign &VA = ArgLocs[i];
+    SDValue Arg = OutVals[i];
+    ISD::ArgFlagsTy Flags = Outs[i].Flags;
+
+    // Promote the value if needed.
+    switch (VA.getLocInfo()) {
+      default:
+        // Loc info must be one of Full, SExt, ZExt, or AExt.
+        assert(0 && "Unknown loc info!");
+      case CCValAssign::Full:
+        break;
+      case CCValAssign::SExt:
+        Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
+        break;
+      case CCValAssign::ZExt:
+        Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
+        break;
+      case CCValAssign::AExt:
+        Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
+        break;
+    }
+
+    if (VA.isMemLoc()) {
+      unsigned LocMemOffset = VA.getLocMemOffset();
+      SDValue PtrOff = DAG.getConstant(LocMemOffset, StackPtr.getValueType());
+      PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
+
+      if (Flags.isByVal()) {
+        // The argument is a struct passed by value. According to LLVM, "Arg"
+        // is is pointer.
+        MemOpChains.push_back(CreateCopyOfByValArgument(Arg, PtrOff, Chain,
+                                                        Flags, DAG, dl));
+      } else {
+        // The argument is not passed by value. "Arg" is a buildin type. It is
+        // not a pointer.
+        MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
+                                           MachinePointerInfo(),false, false,
+                                           0));
+      }
+      continue;
+    }
+
+    // Arguments that can be passed on register must be kept at RegsToPass
+    // vector.
+    if (VA.isRegLoc()) {
+      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
+    }
+  }
+
+  // Transform all store nodes into one single node because all store
+  // nodes are independent of each other.
+  if (!MemOpChains.empty()) {
+    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &MemOpChains[0],
+                        MemOpChains.size());
+  }
+
+  if (!isTailCall)
+    Chain = DAG.getCALLSEQ_START(Chain, DAG.getConstant(NumBytes,
+                                                        getPointerTy(), true));
+
+  // Build a sequence of copy-to-reg nodes chained together with token
+  // chain and flag operands which copy the outgoing args into registers.
+  // The InFlag in necessary since all emited instructions must be
+  // stuck together.
+  SDValue InFlag;
+  if (!isTailCall) {
+    for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
+      Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
+                               RegsToPass[i].second, InFlag);
+      InFlag = Chain.getValue(1);
+    }
+  }
+
+  // For tail calls lower the arguments to the 'real' stack slot.
+  if (isTailCall) {
+    // Force all the incoming stack arguments to be loaded from the stack
+    // before any new outgoing arguments are stored to the stack, because the
+    // outgoing stack slots may alias the incoming argument stack slots, and
+    // the alias isn't otherwise explicit. This is slightly more conservative
+    // than necessary, because it means that each store effectively depends
+    // on every argument instead of just those arguments it would clobber.
+    //
+    // Do not flag preceeding copytoreg stuff together with the following stuff.
+    InFlag = SDValue();
+    for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
+      Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
+                               RegsToPass[i].second, InFlag);
+      InFlag = Chain.getValue(1);
+    }
+    InFlag =SDValue();
+  }
+
+  // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
+  // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
+  // node so that legalize doesn't hack it.
+  if (flag_aligned_memcpy) {
+    const char *MemcpyName =
+      "__hexagon_memcpy_likely_aligned_min32bytes_mult8bytes";
+    Callee =
+      DAG.getTargetExternalSymbol(MemcpyName, getPointerTy());
+    flag_aligned_memcpy = false;
+  } else if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
+    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy());
+  } else if (ExternalSymbolSDNode *S =
+             dyn_cast<ExternalSymbolSDNode>(Callee)) {
+    Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy());
+  }
+
+  // Returns a chain & a flag for retval copy to use.
+  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
+  SmallVector<SDValue, 8> Ops;
+  Ops.push_back(Chain);
+  Ops.push_back(Callee);
+
+  // Add argument registers to the end of the list so that they are
+  // known live into the call.
+  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
+    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
+                                  RegsToPass[i].second.getValueType()));
+  }
+
+  if (InFlag.getNode()) {
+    Ops.push_back(InFlag);
+  }
+
+  if (isTailCall)
+    return DAG.getNode(HexagonISD::TC_RETURN, dl, NodeTys, &Ops[0], Ops.size());
+
+  Chain = DAG.getNode(HexagonISD::CALL, dl, NodeTys, &Ops[0], Ops.size());
+  InFlag = Chain.getValue(1);
+
+  // Create the CALLSEQ_END node.
+  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
+                             DAG.getIntPtrConstant(0, true), InFlag);
+  InFlag = Chain.getValue(1);
+
+  // Handle result values, copying them out of physregs into vregs that we
+  // return.
+  return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins, dl, DAG,
+                         InVals, OutVals, Callee);
+}
+
+static bool getIndexedAddressParts(SDNode *Ptr, EVT VT,
+                                   bool isSEXTLoad, SDValue &Base,
+                                   SDValue &Offset, bool &isInc,
+                                   SelectionDAG &DAG) {
+  if (Ptr->getOpcode() != ISD::ADD)
+  return false;
+
+  if (VT == MVT::i64 || VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8) {
+    isInc = (Ptr->getOpcode() == ISD::ADD);
+    Base = Ptr->getOperand(0);
+    Offset = Ptr->getOperand(1);
+    // Ensure that Offset is a constant.
+    return (isa<ConstantSDNode>(Offset));
+  }
+
+  return false;
+}
+
+// TODO: Put this function along with the other isS* functions in
+// HexagonISelDAGToDAG.cpp into a common file. Or better still, use the
+// functions defined in HexagonImmediates.td.
+static bool Is_PostInc_S4_Offset(SDNode * S, int ShiftAmount) {
+  ConstantSDNode *N = cast<ConstantSDNode>(S);
+
+  // immS4 predicate - True if the immediate fits in a 4-bit sign extended.
+  // field.
+  int64_t v = (int64_t)N->getSExtValue();
+  int64_t m = 0;
+  if (ShiftAmount > 0) {
+    m = v % ShiftAmount;
+    v = v >> ShiftAmount;
+  }
+  return (v <= 7) && (v >= -8) && (m == 0);
+}
+
+/// getPostIndexedAddressParts - returns true by value, base pointer and
+/// offset pointer and addressing mode by reference if this node can be
+/// combined with a load / store to form a post-indexed load / store.
+bool HexagonTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
+                                                       SDValue &Base,
+                                                       SDValue &Offset,
+                                                       ISD::MemIndexedMode &AM,
+                                                       SelectionDAG &DAG) const
+{
+  EVT VT;
+  SDValue Ptr;
+  bool isSEXTLoad = false;
+
+  if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
+    VT  = LD->getMemoryVT();
+    isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
+  } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
+    VT  = ST->getMemoryVT();
+    if (ST->getValue().getValueType() == MVT::i64 && ST->isTruncatingStore()) {
+      return false;
+    }
+  } else {
+    return false;
+  }
+
+  bool isInc;
+  bool isLegal = getIndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
+                                        isInc, DAG);
+  // ShiftAmount = number of left-shifted bits in the Hexagon instruction.
+  int ShiftAmount = VT.getSizeInBits() / 16;
+  if (isLegal && Is_PostInc_S4_Offset(Offset.getNode(), ShiftAmount)) {
+    AM = isInc ? ISD::POST_INC : ISD::POST_DEC;
+    return true;
+  }
+
+  return false;
+}
+
+SDValue HexagonTargetLowering::LowerINLINEASM(SDValue Op,
+                                              SelectionDAG &DAG) const {
+  SDNode *Node = Op.getNode();
+  MachineFunction &MF = DAG.getMachineFunction();
+  HexagonMachineFunctionInfo *FuncInfo =
+    MF.getInfo<HexagonMachineFunctionInfo>();
+  switch (Node->getOpcode()) {
+    case ISD::INLINEASM: {
+      unsigned NumOps = Node->getNumOperands();
+      if (Node->getOperand(NumOps-1).getValueType() == MVT::Glue)
+        --NumOps;  // Ignore the flag operand.
+
+      for (unsigned i = InlineAsm::Op_FirstOperand; i != NumOps;) {
+        if (FuncInfo->hasClobberLR())
+          break;
+        unsigned Flags =
+          cast<ConstantSDNode>(Node->getOperand(i))->getZExtValue();
+        unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
+        ++i;  // Skip the ID value.
+
+        switch (InlineAsm::getKind(Flags)) {
+        default: llvm_unreachable("Bad flags!");
+          case InlineAsm::Kind_RegDef:
+          case InlineAsm::Kind_RegUse:
+          case InlineAsm::Kind_Imm:
+          case InlineAsm::Kind_Clobber:
+          case InlineAsm::Kind_Mem: {
+            for (; NumVals; --NumVals, ++i) {}
+            break;
+          }
+          case InlineAsm::Kind_RegDefEarlyClobber: {
+            for (; NumVals; --NumVals, ++i) {
+              unsigned Reg =
+                cast<RegisterSDNode>(Node->getOperand(i))->getReg();
+
+              // Check it to be lr
+              if (Reg == TM.getRegisterInfo()->getRARegister()) {
+                FuncInfo->setHasClobberLR(true);
+                break;
+              }
+            }
+            break;
+          }
+        }
+      }
+    }
+  } // Node->getOpcode
+  return Op;
+}
+
+
+//
+// Taken from the XCore backend.
+//
+SDValue HexagonTargetLowering::
+LowerBR_JT(SDValue Op, SelectionDAG &DAG) const
+{
+  SDValue Chain = Op.getOperand(0);
+  SDValue Table = Op.getOperand(1);
+  SDValue Index = Op.getOperand(2);
+  DebugLoc dl = Op.getDebugLoc();
+  JumpTableSDNode *JT = cast<JumpTableSDNode>(Table);
+  unsigned JTI = JT->getIndex();
+  MachineFunction &MF = DAG.getMachineFunction();
+  const MachineJumpTableInfo *MJTI = MF.getJumpTableInfo();
+  SDValue TargetJT = DAG.getTargetJumpTable(JT->getIndex(), MVT::i32);
+
+  // Mark all jump table targets as address taken.
+  const std::vector<MachineJumpTableEntry> &JTE = MJTI->getJumpTables();
+  const std::vector<MachineBasicBlock*> &JTBBs = JTE[JTI].MBBs;
+  for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
+    MachineBasicBlock *MBB = JTBBs[i];
+    MBB->setHasAddressTaken();
+    // This line is needed to set the hasAddressTaken flag on the BasicBlock
+    // object.
+    BlockAddress::get(const_cast<BasicBlock *>(MBB->getBasicBlock()));
+  }
+
+  SDValue JumpTableBase = DAG.getNode(HexagonISD::WrapperJT, dl,
+                                      getPointerTy(), TargetJT);
+  SDValue ShiftIndex = DAG.getNode(ISD::SHL, dl, MVT::i32, Index,
+                                   DAG.getConstant(2, MVT::i32));
+  SDValue JTAddress = DAG.getNode(ISD::ADD, dl, MVT::i32, JumpTableBase,
+                                  ShiftIndex);
+  SDValue LoadTarget = DAG.getLoad(MVT::i32, dl, Chain, JTAddress,
+                                   MachinePointerInfo(), false, false, false,
+                                   0);
+  return DAG.getNode(HexagonISD::BR_JT, dl, MVT::Other, Chain, LoadTarget);
+}
+
+
+SDValue
+HexagonTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
+                                               SelectionDAG &DAG) const {
+  SDValue Chain = Op.getOperand(0);
+  SDValue Size = Op.getOperand(1);
+  DebugLoc dl = Op.getDebugLoc();
+
+  unsigned SPReg = getStackPointerRegisterToSaveRestore();
+
+  // Get a reference to the stack pointer.
+  SDValue StackPointer = DAG.getCopyFromReg(Chain, dl, SPReg, MVT::i32);
+
+  // Subtract the dynamic size from the actual stack size to
+  // obtain the new stack size.
+  SDValue Sub = DAG.getNode(ISD::SUB, dl, MVT::i32, StackPointer, Size);
+
+  //
+  // For Hexagon, the outgoing memory arguments area should be on top of the
+  // alloca area on the stack i.e., the outgoing memory arguments should be
+  // at a lower address than the alloca area. Move the alloca area down the
+  // stack by adding back the space reserved for outgoing arguments to SP
+  // here.
+  //
+  // We do not know what the size of the outgoing args is at this point.
+  // So, we add a pseudo instruction ADJDYNALLOC that will adjust the
+  // stack pointer. We patch this instruction with the correct, known
+  // offset in emitPrologue().
+  //
+  // Use a placeholder immediate (zero) for now. This will be patched up
+  // by emitPrologue().
+  SDValue ArgAdjust = DAG.getNode(HexagonISD::ADJDYNALLOC, dl,
+                                  MVT::i32,
+                                  Sub,
+                                  DAG.getConstant(0, MVT::i32));
+
+  // The Sub result contains the new stack start address, so it
+  // must be placed in the stack pointer register.
+  SDValue CopyChain = DAG.getCopyToReg(Chain, dl,
+                                       TM.getRegisterInfo()->getStackRegister(),
+                                       Sub);
+
+  SDValue Ops[2] = { ArgAdjust, CopyChain };
+  return DAG.getMergeValues(Ops, 2, dl);
+}
+
+SDValue
+HexagonTargetLowering::LowerFormalArguments(SDValue Chain,
+                                            CallingConv::ID CallConv,
+                                            bool isVarArg,
+                                            const
+                                            SmallVectorImpl<ISD::InputArg> &Ins,
+                                            DebugLoc dl, SelectionDAG &DAG,
+                                            SmallVectorImpl<SDValue> &InVals)
+const {
+
+  MachineFunction &MF = DAG.getMachineFunction();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  MachineRegisterInfo &RegInfo = MF.getRegInfo();
+  HexagonMachineFunctionInfo *FuncInfo =
+    MF.getInfo<HexagonMachineFunctionInfo>();
+
+
+  // Assign locations to all of the incoming arguments.
+  SmallVector<CCValAssign, 16> ArgLocs;
+  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+		 getTargetMachine(), ArgLocs, *DAG.getContext());
+
+  CCInfo.AnalyzeFormalArguments(Ins, CC_Hexagon);
+
+  // For LLVM, in the case when returning a struct by value (>8byte),
+  // the first argument is a pointer that points to the location on caller's
+  // stack where the return value will be stored. For Hexagon, the location on
+  // caller's stack is passed only when the struct size is smaller than (and
+  // equal to) 8 bytes. If not, no address will be passed into callee and
+  // callee return the result direclty through R0/R1.
+
+  SmallVector<SDValue, 4> MemOps;
+
+  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
+    CCValAssign &VA = ArgLocs[i];
+    ISD::ArgFlagsTy Flags = Ins[i].Flags;
+    unsigned ObjSize;
+    unsigned StackLocation;
+    int FI;
+
+    if (   (VA.isRegLoc() && !Flags.isByVal())
+        || (VA.isRegLoc() && Flags.isByVal() && Flags.getByValSize() > 8)) {
+      // Arguments passed in registers
+      // 1. int, long long, ptr args that get allocated in register.
+      // 2. Large struct that gets an register to put its address in.
+      EVT RegVT = VA.getLocVT();
+      if (RegVT == MVT::i8 || RegVT == MVT::i16 || RegVT == MVT::i32) {
+        unsigned VReg =
+          RegInfo.createVirtualRegister(Hexagon::IntRegsRegisterClass);
+        RegInfo.addLiveIn(VA.getLocReg(), VReg);
+        InVals.push_back(DAG.getCopyFromReg(Chain, dl, VReg, RegVT));
+      } else if (RegVT == MVT::i64) {
+        unsigned VReg =
+          RegInfo.createVirtualRegister(Hexagon::DoubleRegsRegisterClass);
+        RegInfo.addLiveIn(VA.getLocReg(), VReg);
+        InVals.push_back(DAG.getCopyFromReg(Chain, dl, VReg, RegVT));
+      } else {
+        assert (0);
+      }
+    } else if (VA.isRegLoc() && Flags.isByVal() && Flags.getByValSize() <= 8) {
+      assert (0 && "ByValSize must be bigger than 8 bytes");
+    } else {
+      // Sanity check.
+      assert(VA.isMemLoc());
+
+      if (Flags.isByVal()) {
+        // If it's a byval parameter, then we need to compute the
+        // "real" size, not the size of the pointer.
+        ObjSize = Flags.getByValSize();
+      } else {
+        ObjSize = VA.getLocVT().getStoreSizeInBits() >> 3;
+      }
+
+      StackLocation = HEXAGON_LRFP_SIZE + VA.getLocMemOffset();
+      // Create the frame index object for this incoming parameter...
+      FI = MFI->CreateFixedObject(ObjSize, StackLocation, true);
+
+      // Create the SelectionDAG nodes cordl, responding to a load
+      // from this parameter.
+      SDValue FIN = DAG.getFrameIndex(FI, MVT::i32);
+
+      if (Flags.isByVal()) {
+        // If it's a pass-by-value aggregate, then do not dereference the stack
+        // location. Instead, we should generate a reference to the stack
+        // location.
+        InVals.push_back(FIN);
+      } else {
+        InVals.push_back(DAG.getLoad(VA.getLocVT(), dl, Chain, FIN,
+                                     MachinePointerInfo(), false, false,
+                                     false, 0));
+      }
+    }
+  }
+
+  if (!MemOps.empty())
+    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &MemOps[0],
+                        MemOps.size());
+
+  if (isVarArg) {
+    // This will point to the next argument passed via stack.
+    int FrameIndex = MFI->CreateFixedObject(Hexagon_PointerSize,
+                                            HEXAGON_LRFP_SIZE +
+                                            CCInfo.getNextStackOffset(),
+                                            true);
+    FuncInfo->setVarArgsFrameIndex(FrameIndex);
+  }
+
+  return Chain;
+}
+
+SDValue
+HexagonTargetLowering::LowerVASTART(SDValue Op, SelectionDAG &DAG) const {
+  // VASTART stores the address of the VarArgsFrameIndex slot into the
+  // memory location argument.
+  MachineFunction &MF = DAG.getMachineFunction();
+  HexagonMachineFunctionInfo *QFI = MF.getInfo<HexagonMachineFunctionInfo>();
+  SDValue Addr = DAG.getFrameIndex(QFI->getVarArgsFrameIndex(), MVT::i32);
+  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
+  return DAG.getStore(Op.getOperand(0), Op.getDebugLoc(), Addr,
+                      Op.getOperand(1), MachinePointerInfo(SV), false,
+                      false, 0);
+}
+
+SDValue
+HexagonTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
+  SDNode* OpNode = Op.getNode();
+
+  SDValue Cond = DAG.getNode(ISD::SETCC, Op.getDebugLoc(), MVT::i1,
+                             Op.getOperand(2), Op.getOperand(3),
+                             Op.getOperand(4));
+  return DAG.getNode(ISD::SELECT, Op.getDebugLoc(), OpNode->getValueType(0),
+                     Cond, Op.getOperand(0),
+                     Op.getOperand(1));
+}
+
+SDValue
+HexagonTargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const {
+  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
+  MachineFunction &MF = DAG.getMachineFunction();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  MFI->setReturnAddressIsTaken(true);
+
+  EVT VT = Op.getValueType();
+  DebugLoc dl = Op.getDebugLoc();
+  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
+  if (Depth) {
+    SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
+    SDValue Offset = DAG.getConstant(4, MVT::i32);
+    return DAG.getLoad(VT, dl, DAG.getEntryNode(),
+                       DAG.getNode(ISD::ADD, dl, VT, FrameAddr, Offset),
+                       MachinePointerInfo(), false, false, false, 0);
+  }
+
+  // Return LR, which contains the return address. Mark it an implicit live-in.
+  unsigned Reg = MF.addLiveIn(TRI->getRARegister(), getRegClassFor(MVT::i32));
+  return DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg, VT);
+}
+
+SDValue
+HexagonTargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
+  const HexagonRegisterInfo  *TRI = TM.getRegisterInfo();
+  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
+  MFI->setFrameAddressIsTaken(true);
+
+  EVT VT = Op.getValueType();
+  DebugLoc dl = Op.getDebugLoc();
+  unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
+  SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl,
+                                         TRI->getFrameRegister(), VT);
+  while (Depth--)
+    FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr,
+                            MachinePointerInfo(),
+                            false, false, false, 0);
+  return FrameAddr;
+}
+
+
+SDValue HexagonTargetLowering::LowerMEMBARRIER(SDValue Op,
+                                               SelectionDAG& DAG) const {
+  DebugLoc dl = Op.getDebugLoc();
+  return DAG.getNode(HexagonISD::BARRIER, dl, MVT::Other,  Op.getOperand(0));
+}
+
+
+SDValue HexagonTargetLowering::LowerATOMIC_FENCE(SDValue Op,
+                                                 SelectionDAG& DAG) const {
+  DebugLoc dl = Op.getDebugLoc();
+  return DAG.getNode(HexagonISD::BARRIER, dl, MVT::Other, Op.getOperand(0));
+}
+
+
+SDValue HexagonTargetLowering::LowerGLOBALADDRESS(SDValue Op,
+                                                  SelectionDAG &DAG) const {
+  SDValue Result;
+  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
+  int64_t Offset = cast<GlobalAddressSDNode>(Op)->getOffset();
+  DebugLoc dl = Op.getDebugLoc();
+  Result = DAG.getTargetGlobalAddress(GV, dl, getPointerTy(), Offset);
+
+  HexagonTargetObjectFile &TLOF =
+    (HexagonTargetObjectFile&)getObjFileLowering();
+  if (TLOF.IsGlobalInSmallSection(GV, getTargetMachine())) {
+    return DAG.getNode(HexagonISD::CONST32_GP, dl, getPointerTy(), Result);
+  }
+
+  return DAG.getNode(HexagonISD::CONST32, dl, getPointerTy(), Result);
+}
+
+//===----------------------------------------------------------------------===//
+// TargetLowering Implementation
+//===----------------------------------------------------------------------===//
+
+HexagonTargetLowering::HexagonTargetLowering(HexagonTargetMachine
+                                             &targetmachine)
+  : TargetLowering(targetmachine, new HexagonTargetObjectFile()),
+    TM(targetmachine) {
+
+    // Set up the register classes.
+    addRegisterClass(MVT::i32, Hexagon::IntRegsRegisterClass);
+    addRegisterClass(MVT::i64, Hexagon::DoubleRegsRegisterClass);
+
+    addRegisterClass(MVT::i1, Hexagon::PredRegsRegisterClass);
+
+    computeRegisterProperties();
+
+    // Align loop entry
+    setPrefLoopAlignment(4);
+
+    // Limits for inline expansion of memcpy/memmove
+    maxStoresPerMemcpy = 6;
+    maxStoresPerMemmove = 6;
+
+    //
+    // Library calls for unsupported operations
+    //
+    setLibcallName(RTLIB::OGT_F64, "__hexagon_gtdf2");
+
+    setLibcallName(RTLIB::SINTTOFP_I64_F64, "__hexagon_floatdidf");
+    setLibcallName(RTLIB::SINTTOFP_I128_F64, "__hexagon_floattidf");
+    setLibcallName(RTLIB::SINTTOFP_I128_F32, "__hexagon_floattisf");
+    setLibcallName(RTLIB::UINTTOFP_I32_F32, "__hexagon_floatunsisf");
+    setLibcallName(RTLIB::UINTTOFP_I64_F32, "__hexagon_floatundisf");
+    setLibcallName(RTLIB::SINTTOFP_I64_F32, "__hexagon_floatdisf");
+    setLibcallName(RTLIB::UINTTOFP_I64_F64, "__hexagon_floatundidf");
+
+    setLibcallName(RTLIB::FPTOUINT_F32_I32, "__hexagon_fixunssfsi");
+    setLibcallName(RTLIB::FPTOUINT_F32_I64, "__hexagon_fixunssfdi");
+    setLibcallName(RTLIB::FPTOUINT_F32_I128, "__hexagon_fixunssfti");
+
+    setLibcallName(RTLIB::FPTOUINT_F64_I32, "__hexagon_fixunsdfsi");
+    setLibcallName(RTLIB::FPTOUINT_F64_I64, "__hexagon_fixunsdfdi");
+    setLibcallName(RTLIB::FPTOUINT_F64_I128, "__hexagon_fixunsdfti");
+
+    setLibcallName(RTLIB::UINTTOFP_I32_F64, "__hexagon_floatunsidf");
+    setLibcallName(RTLIB::FPTOSINT_F32_I64, "__hexagon_fixsfdi");
+    setLibcallName(RTLIB::FPTOSINT_F32_I128, "__hexagon_fixsfti");
+    setLibcallName(RTLIB::FPTOSINT_F64_I64, "__hexagon_fixdfdi");
+    setLibcallName(RTLIB::FPTOSINT_F64_I128, "__hexagon_fixdfti");
+
+    setLibcallName(RTLIB::OGT_F64, "__hexagon_gtdf2");
+
+    setLibcallName(RTLIB::SDIV_I32, "__hexagon_divsi3");
+    setOperationAction(ISD::SDIV,  MVT::i32, Expand);
+    setLibcallName(RTLIB::SREM_I32, "__hexagon_umodsi3");
+    setOperationAction(ISD::SREM,  MVT::i32, Expand);
+
+    setLibcallName(RTLIB::SDIV_I64, "__hexagon_divdi3");
+    setOperationAction(ISD::SDIV,  MVT::i64, Expand);
+    setLibcallName(RTLIB::SREM_I64, "__hexagon_moddi3");
+    setOperationAction(ISD::SREM,  MVT::i64, Expand);
+
+    setLibcallName(RTLIB::UDIV_I32, "__hexagon_udivsi3");
+    setOperationAction(ISD::UDIV,  MVT::i32, Expand);
+
+    setLibcallName(RTLIB::UDIV_I64, "__hexagon_udivdi3");
+    setOperationAction(ISD::UDIV,  MVT::i64, Expand);
+
+    setLibcallName(RTLIB::UREM_I32, "__hexagon_umodsi3");
+    setOperationAction(ISD::UREM,  MVT::i32, Expand);
+
+    setLibcallName(RTLIB::UREM_I64, "__hexagon_umoddi3");
+    setOperationAction(ISD::UREM,  MVT::i64, Expand);
+
+    setLibcallName(RTLIB::DIV_F32, "__hexagon_divsf3");
+    setOperationAction(ISD::FDIV,  MVT::f32, Expand);
+
+    setLibcallName(RTLIB::DIV_F64, "__hexagon_divdf3");
+    setOperationAction(ISD::FDIV,  MVT::f64, Expand);
+
+    setLibcallName(RTLIB::FPEXT_F32_F64, "__hexagon_extendsfdf2");
+    setOperationAction(ISD::FP_EXTEND,  MVT::f32, Expand);
+
+    setLibcallName(RTLIB::SINTTOFP_I32_F32, "__hexagon_floatsisf");
+    setOperationAction(ISD::SINT_TO_FP,  MVT::i32, Expand);
+
+    setLibcallName(RTLIB::ADD_F64, "__hexagon_adddf3");
+    setOperationAction(ISD::FADD,  MVT::f64, Expand);
+
+    setLibcallName(RTLIB::ADD_F32, "__hexagon_addsf3");
+    setOperationAction(ISD::FADD,  MVT::f32, Expand);
+
+    setLibcallName(RTLIB::ADD_F32, "__hexagon_addsf3");
+    setOperationAction(ISD::FADD,  MVT::f32, Expand);
+
+    setLibcallName(RTLIB::OEQ_F32, "__hexagon_eqsf2");
+    setCondCodeAction(ISD::SETOEQ, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::FPTOSINT_F64_I32, "__hexagon_fixdfsi");
+    setOperationAction(ISD::FP_TO_SINT, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::FPTOSINT_F32_I32, "__hexagon_fixsfsi");
+    setOperationAction(ISD::FP_TO_SINT, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::SINTTOFP_I32_F64, "__hexagon_floatsidf");
+    setOperationAction(ISD::SINT_TO_FP, MVT::i32, Expand);
+
+    setLibcallName(RTLIB::OGE_F64, "__hexagon_gedf2");
+    setCondCodeAction(ISD::SETOGE, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::OGE_F32, "__hexagon_gesf2");
+    setCondCodeAction(ISD::SETOGE, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::OGT_F32, "__hexagon_gtsf2");
+    setCondCodeAction(ISD::SETOGT, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::OLE_F64, "__hexagon_ledf2");
+    setCondCodeAction(ISD::SETOLE, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::OLE_F32, "__hexagon_lesf2");
+    setCondCodeAction(ISD::SETOLE, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::OLT_F64, "__hexagon_ltdf2");
+    setCondCodeAction(ISD::SETOLT, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::OLT_F32, "__hexagon_ltsf2");
+    setCondCodeAction(ISD::SETOLT, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::SREM_I32, "__hexagon_modsi3");
+    setOperationAction(ISD::SREM, MVT::i32, Expand);
+
+    setLibcallName(RTLIB::MUL_F64, "__hexagon_muldf3");
+    setOperationAction(ISD::FMUL, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::MUL_F32, "__hexagon_mulsf3");
+    setOperationAction(ISD::MUL, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::UNE_F64, "__hexagon_nedf2");
+    setCondCodeAction(ISD::SETUNE, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::UNE_F32, "__hexagon_nesf2");
+
+
+    setLibcallName(RTLIB::SUB_F64, "__hexagon_subdf3");
+    setOperationAction(ISD::SUB, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::SUB_F32, "__hexagon_subsf3");
+    setOperationAction(ISD::SUB, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::FPROUND_F64_F32, "__hexagon_truncdfsf2");
+    setOperationAction(ISD::FP_ROUND, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::UO_F64, "__hexagon_unorddf2");
+    setCondCodeAction(ISD::SETUO, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::O_F64, "__hexagon_unorddf2");
+    setCondCodeAction(ISD::SETO, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::OEQ_F64, "__hexagon_eqdf2");
+    setCondCodeAction(ISD::SETOEQ, MVT::f64, Expand);
+
+    setLibcallName(RTLIB::O_F32, "__hexagon_unordsf2");
+    setCondCodeAction(ISD::SETO, MVT::f32, Expand);
+
+    setLibcallName(RTLIB::UO_F32, "__hexagon_unordsf2");
+    setCondCodeAction(ISD::SETUO, MVT::f32, Expand);
+
+    setIndexedLoadAction(ISD::POST_INC, MVT::i8, Legal);
+    setIndexedLoadAction(ISD::POST_INC, MVT::i16, Legal);
+    setIndexedLoadAction(ISD::POST_INC, MVT::i32, Legal);
+    setIndexedLoadAction(ISD::POST_INC, MVT::i64, Legal);
+
+    setIndexedStoreAction(ISD::POST_INC, MVT::i8, Legal);
+    setIndexedStoreAction(ISD::POST_INC, MVT::i16, Legal);
+    setIndexedStoreAction(ISD::POST_INC, MVT::i32, Legal);
+    setIndexedStoreAction(ISD::POST_INC, MVT::i64, Legal);
+
+    setOperationAction(ISD::BUILD_PAIR, MVT::i64, Expand);
+
+    // Turn FP extload into load/fextend.
+    setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
+    // Hexagon has a i1 sign extending load.
+    setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Expand);
+    // Turn FP truncstore into trunc + store.
+    setTruncStoreAction(MVT::f64, MVT::f32, Expand);
+
+    // Custom legalize GlobalAddress nodes into CONST32.
+    setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
+    setOperationAction(ISD::GlobalAddress, MVT::i8, Custom);
+    // Truncate action?
+    setOperationAction(ISD::TRUNCATE, MVT::i64, Expand);
+
+    // Hexagon doesn't have sext_inreg, replace them with shl/sra.
+    setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1 , Expand);
+
+    // Hexagon has no REM or DIVREM operations.
+    setOperationAction(ISD::UREM, MVT::i32, Expand);
+    setOperationAction(ISD::SREM, MVT::i32, Expand);
+    setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
+    setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
+    setOperationAction(ISD::SREM, MVT::i64, Expand);
+    setOperationAction(ISD::SDIVREM, MVT::i64, Expand);
+    setOperationAction(ISD::UDIVREM, MVT::i64, Expand);
+
+    setOperationAction(ISD::BSWAP, MVT::i64, Expand);
+
+    // Expand fp<->uint.
+    setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
+    setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand);
+
+    // Hexagon has no select or setcc: expand to SELECT_CC.
+    setOperationAction(ISD::SELECT, MVT::f32, Expand);
+    setOperationAction(ISD::SELECT, MVT::f64, Expand);
+
+    // Lower SELECT_CC to SETCC and SELECT.
+    setOperationAction(ISD::SELECT_CC, MVT::i32,   Custom);
+    setOperationAction(ISD::SELECT_CC, MVT::i64,   Custom);
+    // This is a workaround documented in DAGCombiner.cpp:2892 We don't
+    // support SELECT_CC on every type.
+    setOperationAction(ISD::SELECT_CC, MVT::Other,   Expand);
+
+    setOperationAction(ISD::BR_CC, MVT::Other, Expand);
+    setOperationAction(ISD::BRIND, MVT::Other, Expand);
+    if (EmitJumpTables) {
+      setOperationAction(ISD::BR_JT, MVT::Other, Custom);
+    } else {
+      setOperationAction(ISD::BR_JT, MVT::Other, Expand);
+    }
+
+    setOperationAction(ISD::BR_CC, MVT::i32, Expand);
+
+    setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom);
+    setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Custom);
+
+    setOperationAction(ISD::FSIN , MVT::f64, Expand);
+    setOperationAction(ISD::FCOS , MVT::f64, Expand);
+    setOperationAction(ISD::FREM , MVT::f64, Expand);
+    setOperationAction(ISD::FSIN , MVT::f32, Expand);
+    setOperationAction(ISD::FCOS , MVT::f32, Expand);
+    setOperationAction(ISD::FREM , MVT::f32, Expand);
+    setOperationAction(ISD::CTPOP, MVT::i32, Expand);
+    setOperationAction(ISD::CTTZ , MVT::i32, Expand);
+    setOperationAction(ISD::CTLZ , MVT::i32, Expand);
+    setOperationAction(ISD::ROTL , MVT::i32, Expand);
+    setOperationAction(ISD::ROTR , MVT::i32, Expand);
+    setOperationAction(ISD::BSWAP, MVT::i32, Expand);
+    setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
+    setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
+    setOperationAction(ISD::FPOW , MVT::f64, Expand);
+    setOperationAction(ISD::FPOW , MVT::f32, Expand);
+
+    setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
+    setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
+    setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
+
+    setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
+    setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
+
+    setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand);
+    setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
+
+    setOperationAction(ISD::EXCEPTIONADDR, MVT::i64, Expand);
+    setOperationAction(ISD::EHSELECTION,   MVT::i64, Expand);
+    setOperationAction(ISD::EXCEPTIONADDR, MVT::i32, Expand);
+    setOperationAction(ISD::EHSELECTION,   MVT::i32, Expand);
+
+    setOperationAction(ISD::EH_RETURN,     MVT::Other, Expand);
+
+    if (TM.getSubtargetImpl()->isSubtargetV2()) {
+      setExceptionPointerRegister(Hexagon::R20);
+      setExceptionSelectorRegister(Hexagon::R21);
+    } else {
+      setExceptionPointerRegister(Hexagon::R0);
+      setExceptionSelectorRegister(Hexagon::R1);
+    }
+
+    // VASTART needs to be custom lowered to use the VarArgsFrameIndex.
+    setOperationAction(ISD::VASTART           , MVT::Other, Custom);
+
+    // Use the default implementation.
+    setOperationAction(ISD::VAARG             , MVT::Other, Expand);
+    setOperationAction(ISD::VACOPY            , MVT::Other, Expand);
+    setOperationAction(ISD::VAEND             , MVT::Other, Expand);
+    setOperationAction(ISD::STACKSAVE         , MVT::Other, Expand);
+    setOperationAction(ISD::STACKRESTORE      , MVT::Other, Expand);
+
+
+    setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32  , Custom);
+    setOperationAction(ISD::INLINEASM         , MVT::Other, Custom);
+
+    setMinFunctionAlignment(2);
+
+    // Needed for DYNAMIC_STACKALLOC expansion.
+    unsigned StackRegister = TM.getRegisterInfo()->getStackRegister();
+    setStackPointerRegisterToSaveRestore(StackRegister);
+}
+
+
+const char*
+HexagonTargetLowering::getTargetNodeName(unsigned Opcode) const {
+  switch (Opcode) {
+    default: return 0;
+    case HexagonISD::CONST32:    return "HexagonISD::CONST32";
+    case HexagonISD::ADJDYNALLOC: return "HexagonISD::ADJDYNALLOC";
+    case HexagonISD::CMPICC:     return "HexagonISD::CMPICC";
+    case HexagonISD::CMPFCC:     return "HexagonISD::CMPFCC";
+    case HexagonISD::BRICC:      return "HexagonISD::BRICC";
+    case HexagonISD::BRFCC:      return "HexagonISD::BRFCC";
+    case HexagonISD::SELECT_ICC: return "HexagonISD::SELECT_ICC";
+    case HexagonISD::SELECT_FCC: return "HexagonISD::SELECT_FCC";
+    case HexagonISD::Hi:         return "HexagonISD::Hi";
+    case HexagonISD::Lo:         return "HexagonISD::Lo";
+    case HexagonISD::FTOI:       return "HexagonISD::FTOI";
+    case HexagonISD::ITOF:       return "HexagonISD::ITOF";
+    case HexagonISD::CALL:       return "HexagonISD::CALL";
+    case HexagonISD::RET_FLAG:   return "HexagonISD::RET_FLAG";
+    case HexagonISD::BR_JT:      return "HexagonISD::BR_JT";
+    case HexagonISD::TC_RETURN:  return "HexagonISD::TC_RETURN";
+  }
+}
+
+bool
+HexagonTargetLowering::isTruncateFree(Type *Ty1, Type *Ty2) const {
+  EVT MTy1 = EVT::getEVT(Ty1);
+  EVT MTy2 = EVT::getEVT(Ty2);
+  if (!MTy1.isSimple() || !MTy2.isSimple()) {
+    return false;
+  }
+  return ((MTy1.getSimpleVT() == MVT::i64) && (MTy2.getSimpleVT() == MVT::i32));
+}
+
+bool HexagonTargetLowering::isTruncateFree(EVT VT1, EVT VT2) const {
+  if (!VT1.isSimple() || !VT2.isSimple()) {
+    return false;
+  }
+  return ((VT1.getSimpleVT() == MVT::i64) && (VT2.getSimpleVT() == MVT::i32));
+}
+
+SDValue
+HexagonTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
+  switch (Op.getOpcode()) {
+    default: assert(0 && "Should not custom lower this!");
+      // Frame & Return address.  Currently unimplemented.
+    case ISD::RETURNADDR: return LowerRETURNADDR(Op, DAG);
+    case ISD::FRAMEADDR:  return LowerFRAMEADDR(Op, DAG);
+    case ISD::GlobalTLSAddress:
+                          assert(0 && "TLS not implemented for Hexagon.");
+    case ISD::MEMBARRIER:         return LowerMEMBARRIER(Op, DAG);
+    case ISD::ATOMIC_FENCE:       return LowerATOMIC_FENCE(Op, DAG);
+    case ISD::GlobalAddress:      return LowerGLOBALADDRESS(Op, DAG);
+    case ISD::VASTART:            return LowerVASTART(Op, DAG);
+    case ISD::BR_JT:              return LowerBR_JT(Op, DAG);
+
+    case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
+    case ISD::SELECT_CC:        return LowerSELECT_CC(Op, DAG);
+    case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG);
+  case ISD::INLINEASM:          return LowerINLINEASM(Op, DAG);
+
+  }
+}
+
+
+
+//===----------------------------------------------------------------------===//
+//                           Hexagon Scheduler Hooks
+//===----------------------------------------------------------------------===//
+MachineBasicBlock *
+HexagonTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
+                                                   MachineBasicBlock *BB)
+const {
+  switch (MI->getOpcode()) {
+    case Hexagon::ADJDYNALLOC: {
+      MachineFunction *MF = BB->getParent();
+      HexagonMachineFunctionInfo *FuncInfo =
+        MF->getInfo<HexagonMachineFunctionInfo>();
+      FuncInfo->addAllocaAdjustInst(MI);
+      return BB;
+    }
+    default:
+      assert(false && "Unexpected instr type to insert");
+  } // switch
+  return NULL;
+}
+
+//===----------------------------------------------------------------------===//
+// Inline Assembly Support
+//===----------------------------------------------------------------------===//
+
+std::pair<unsigned, const TargetRegisterClass*>
+HexagonTargetLowering::getRegForInlineAsmConstraint(const
+                                                    std::string &Constraint,
+                                                    EVT VT) const {
+  if (Constraint.size() == 1) {
+    switch (Constraint[0]) {
+    case 'r':   // R0-R31
+       switch (VT.getSimpleVT().SimpleTy) {
+       default:
+         assert(0 && "getRegForInlineAsmConstraint Unhandled data type");
+       case MVT::i32:
+       case MVT::i16:
+       case MVT::i8:
+         return std::make_pair(0U, Hexagon::IntRegsRegisterClass);
+       case MVT::i64:
+         return std::make_pair(0U, Hexagon::DoubleRegsRegisterClass);
+      }
+    default:
+      assert(0 && "Unknown asm register class");
+    }
+  }
+
+  return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
+}
+
+/// isLegalAddressingMode - Return true if the addressing mode represented by
+/// AM is legal for this target, for a load/store of the specified type.
+bool HexagonTargetLowering::isLegalAddressingMode(const AddrMode &AM,
+                                                  Type *Ty) const {
+  // Allows a signed-extended 11-bit immediate field.
+  if (AM.BaseOffs <= -(1LL << 13) || AM.BaseOffs >= (1LL << 13)-1) {
+    return false;
+  }
+
+  // No global is ever allowed as a base.
+  if (AM.BaseGV) {
+    return false;
+  }
+
+  int Scale = AM.Scale;
+  if (Scale < 0) Scale = -Scale;
+  switch (Scale) {
+  case 0:  // No scale reg, "r+i", "r", or just "i".
+    break;
+  default: // No scaled addressing mode.
+    return false;
+  }
+  return true;
+}
+
+/// isLegalICmpImmediate - Return true if the specified immediate is legal
+/// icmp immediate, that is the target has icmp instructions which can compare
+/// a register against the immediate without having to materialize the
+/// immediate into a register.
+bool HexagonTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
+  return Imm >= -512 && Imm <= 511;
+}
+
+/// IsEligibleForTailCallOptimization - Check whether the call is eligible
+/// for tail call optimization. Targets which want to do tail call
+/// optimization should implement this function.
+bool HexagonTargetLowering::IsEligibleForTailCallOptimization(
+                                 SDValue Callee,
+                                 CallingConv::ID CalleeCC,
+                                 bool isVarArg,
+                                 bool isCalleeStructRet,
+                                 bool isCallerStructRet,
+                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
+                                 const SmallVectorImpl<SDValue> &OutVals,
+                                 const SmallVectorImpl<ISD::InputArg> &Ins,
+                                 SelectionDAG& DAG) const {
+  const Function *CallerF = DAG.getMachineFunction().getFunction();
+  CallingConv::ID CallerCC = CallerF->getCallingConv();
+  bool CCMatch = CallerCC == CalleeCC;
+
+  // ***************************************************************************
+  //  Look for obvious safe cases to perform tail call optimization that do not
+  //  require ABI changes.
+  // ***************************************************************************
+
+  // If this is a tail call via a function pointer, then don't do it!
+  if (!(dyn_cast<GlobalAddressSDNode>(Callee))
+      && !(dyn_cast<ExternalSymbolSDNode>(Callee))) {
+    return false;
+  }
+
+  // Do not optimize if the calling conventions do not match.
+  if (!CCMatch)
+    return false;
+
+  // Do not tail call optimize vararg calls.
+  if (isVarArg)
+    return false;
+
+  // Also avoid tail call optimization if either caller or callee uses struct
+  // return semantics.
+  if (isCalleeStructRet || isCallerStructRet)
+    return false;
+
+  // In addition to the cases above, we also disable Tail Call Optimization if
+  // the calling convention code that at least one outgoing argument needs to
+  // go on the stack. We cannot check that here because at this point that
+  // information is not available.
+  return true;
+}