Extend Hexagon hardware loop generation to handle various additional cases:

- variety of compare instructions,
- loops with no preheader,
- arbitrary lower and upper bounds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174904 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 2998 insertions, 382 deletions

diff --git a/lib/Target/Hexagon/CMakeLists.txt b/lib/Target/Hexagon/CMakeLists.txt
index aee43ba517..b5b887e7c7 100644
--- a/lib/Target/Hexagon/CMakeLists.txt
+++ b/lib/Target/Hexagon/CMakeLists.txt
@@ -18,6 +18,7 @@ add_llvm_target(HexagonCodeGen
   HexagonExpandPredSpillCode.cpp
   HexagonFrameLowering.cpp
   HexagonHardwareLoops.cpp
+  HexagonFixupHwLoops.cpp
   HexagonMachineScheduler.cpp
   HexagonMCInstLower.cpp
   HexagonInstrInfo.cpp
diff --git a/lib/Target/Hexagon/HexagonFixupHwLoops.cpp b/lib/Target/Hexagon/HexagonFixupHwLoops.cpp
new file mode 100644
index 0000000000..240cc95666
--- /dev/null
+++ b/lib/Target/Hexagon/HexagonFixupHwLoops.cpp
@@ -0,0 +1,183 @@
+//===---- HexagonFixupHwLoops.cpp - Fixup HW loops too far from LOOPn. ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+// The loop start address in the LOOPn instruction is encoded as a distance
+// from the LOOPn instruction itself.  If the start address is too far from
+// the LOOPn instruction, the loop needs to be set up manually, i.e. via
+// direct transfers to SAn and LCn.
+// This pass will identify and convert such LOOPn instructions to a proper
+// form.
+//===----------------------------------------------------------------------===//
+
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/PassSupport.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "Hexagon.h"
+#include "HexagonTargetMachine.h"
+
+using namespace llvm;
+
+namespace llvm {
+  void initializeHexagonFixupHwLoopsPass(PassRegistry&);
+}
+
+namespace {
+  struct HexagonFixupHwLoops : public MachineFunctionPass {
+  public:
+    static char ID;
+
+    HexagonFixupHwLoops() : MachineFunctionPass(ID) {
+      initializeHexagonFixupHwLoopsPass(*PassRegistry::getPassRegistry());
+    }
+
+    virtual bool runOnMachineFunction(MachineFunction &MF);
+
+    const char *getPassName() const { return "Hexagon Hardware Loop Fixup"; }
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesCFG();
+      MachineFunctionPass::getAnalysisUsage(AU);
+    }
+
+  private:
+    /// \brief Maximum distance between the loop instr and the basic block.
+    /// Just an estimate.
+    static const unsigned MAX_LOOP_DISTANCE = 200;
+
+    /// \brief Check the offset between each loop instruction and
+    /// the loop basic block to determine if we can use the LOOP instruction
+    /// or if we need to set the LC/SA registers explicitly.
+    bool fixupLoopInstrs(MachineFunction &MF);
+
+    /// \brief Add the instruction to set the LC and SA registers explicitly.
+    void convertLoopInstr(MachineFunction &MF,
+                          MachineBasicBlock::iterator &MII,
+                          RegScavenger &RS);
+
+  };
+
+  char HexagonFixupHwLoops::ID = 0;
+}
+
+INITIALIZE_PASS(HexagonFixupHwLoops, "hwloopsfixup",
+                "Hexagon Hardware Loops Fixup", false, false)
+
+FunctionPass *llvm::createHexagonFixupHwLoops() {
+  return new HexagonFixupHwLoops();
+}
+
+
+/// \brief Returns true if the instruction is a hardware loop instruction.
+static bool isHardwareLoop(const MachineInstr *MI) {
+  return MI->getOpcode() == Hexagon::LOOP0_r ||
+         MI->getOpcode() == Hexagon::LOOP0_i;
+}
+
+
+bool HexagonFixupHwLoops::runOnMachineFunction(MachineFunction &MF) {
+  bool Changed = fixupLoopInstrs(MF);
+  return Changed;
+}
+
+
+/// \brief For Hexagon, if the loop label is to far from the
+/// loop instruction then we need to set the LC0 and SA0 registers
+/// explicitly instead of using LOOP(start,count).  This function
+/// checks the distance, and generates register assignments if needed.
+///
+/// This function makes two passes over the basic blocks.  The first
+/// pass computes the offset of the basic block from the start.
+/// The second pass checks all the loop instructions.
+bool HexagonFixupHwLoops::fixupLoopInstrs(MachineFunction &MF) {
+
+  // Offset of the current instruction from the start.
+  unsigned InstOffset = 0;
+  // Map for each basic block to it's first instruction.
+  DenseMap<MachineBasicBlock*, unsigned> BlockToInstOffset;
+
+  // First pass - compute the offset of each basic block.
+  for (MachineFunction::iterator MBB = MF.begin(), MBBe = MF.end();
+       MBB != MBBe; ++MBB) {
+    BlockToInstOffset[MBB] = InstOffset;
+    InstOffset += (MBB->size() * 4);
+  }
+
+  // Second pass - check each loop instruction to see if it needs to
+  // be converted.
+  InstOffset = 0;
+  bool Changed = false;
+  RegScavenger RS;
+
+  // Loop over all the basic blocks.
+  for (MachineFunction::iterator MBB = MF.begin(), MBBe = MF.end();
+       MBB != MBBe; ++MBB) {
+    InstOffset = BlockToInstOffset[MBB];
+    RS.enterBasicBlock(MBB);
+
+    // Loop over all the instructions.
+    MachineBasicBlock::iterator MIE = MBB->end();
+    MachineBasicBlock::iterator MII = MBB->begin();
+    while (MII != MIE) {
+      if (isHardwareLoop(MII)) {
+        RS.forward(MII);
+        assert(MII->getOperand(0).isMBB() &&
+               "Expect a basic block as loop operand");
+        int Sub = InstOffset - BlockToInstOffset[MII->getOperand(0).getMBB()];
+        unsigned Dist = Sub > 0 ? Sub : -Sub;
+        if (Dist > MAX_LOOP_DISTANCE) {
+          // Convert to explicity setting LC0 and SA0.
+          convertLoopInstr(MF, MII, RS);
+          MII = MBB->erase(MII);
+          Changed = true;
+        } else {
+          ++MII;
+        }
+      } else {
+        ++MII;
+      }
+      InstOffset += 4;
+    }
+  }
+
+  return Changed;
+}
+
+
+/// \brief convert a loop instruction to a sequence of instructions that
+/// set the LC0 and SA0 register explicitly.
+void HexagonFixupHwLoops::convertLoopInstr(MachineFunction &MF,
+                                           MachineBasicBlock::iterator &MII,
+                                           RegScavenger &RS) {
+  const TargetInstrInfo *TII = MF.getTarget().getInstrInfo();
+  MachineBasicBlock *MBB = MII->getParent();
+  DebugLoc DL = MII->getDebugLoc();
+  unsigned Scratch = RS.scavengeRegister(&Hexagon::IntRegsRegClass, MII, 0);
+
+  // First, set the LC0 with the trip count.
+  if (MII->getOperand(1).isReg()) {
+    // Trip count is a register
+    BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFCR), Hexagon::LC0)
+      .addReg(MII->getOperand(1).getReg());
+  } else {
+    // Trip count is an immediate.
+    BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFRI), Scratch)
+      .addImm(MII->getOperand(1).getImm());
+    BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFCR), Hexagon::LC0)
+      .addReg(Scratch);
+  }
+  // Then, set the SA0 with the loop start address.
+  BuildMI(*MBB, MII, DL, TII->get(Hexagon::CONST32_Label), Scratch)
+    .addMBB(MII->getOperand(0).getMBB());
+  BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFCR), Hexagon::SA0)
+    .addReg(Scratch);
+}
diff --git a/lib/Target/Hexagon/HexagonHardwareLoops.cpp b/lib/Target/Hexagon/HexagonHardwareLoops.cpp
index 2a00a9f7bd..62aed1353c 100644
--- a/lib/Target/Hexagon/HexagonHardwareLoops.cpp
+++ b/lib/Target/Hexagon/HexagonHardwareLoops.cpp
@@ -27,9 +27,7 @@
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "hwloops"
-#include "Hexagon.h"
-#include "HexagonTargetMachine.h"
-#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFunction.h"
@@ -37,79 +35,194 @@
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/RegisterScavenging.h"
-#include "llvm/IR/Constants.h"
 #include "llvm/PassSupport.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetInstrInfo.h"
+#include "Hexagon.h"
+#include "HexagonTargetMachine.h"
+
 #include <algorithm>
+#include <vector>
 
 using namespace llvm;
 
+#ifndef NDEBUG
+static cl::opt<int> HWLoopLimit("max-hwloop", cl::Hidden, cl::init(-1));
+#endif
+
 STATISTIC(NumHWLoops, "Number of loops converted to hardware loops");
 
+namespace llvm {
+  void initializeHexagonHardwareLoopsPass(PassRegistry&);
+}
+
 namespace {
   class CountValue;
   struct HexagonHardwareLoops : public MachineFunctionPass {
-    MachineLoopInfo       *MLI;
-    MachineRegisterInfo   *MRI;
-    const TargetInstrInfo *TII;
+    MachineLoopInfo            *MLI;
+    MachineRegisterInfo        *MRI;
+    MachineDominatorTree       *MDT;
+    const HexagonTargetMachine *TM;
+    const HexagonInstrInfo     *TII;
+    const HexagonRegisterInfo  *TRI;
+#ifndef NDEBUG
+    static int Counter;
+#endif
 
   public:
-    static char ID;   // Pass identification, replacement for typeid
+    static char ID;
 
-    HexagonHardwareLoops() : MachineFunctionPass(ID) {}
+    HexagonHardwareLoops() : MachineFunctionPass(ID) {
+      initializeHexagonHardwareLoopsPass(*PassRegistry::getPassRegistry());
+    }
 
     virtual bool runOnMachineFunction(MachineFunction &MF);
 
     const char *getPassName() const { return "Hexagon Hardware Loops"; }
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      AU.setPreservesCFG();
       AU.addRequired<MachineDominatorTree>();
-      AU.addPreserved<MachineDominatorTree>();
       AU.addRequired<MachineLoopInfo>();
-      AU.addPreserved<MachineLoopInfo>();
       MachineFunctionPass::getAnalysisUsage(AU);
     }
 
   private:
-    /// getCanonicalInductionVariable - Check to see if the loop has a canonical
-    /// induction variable.
-    /// Should be defined in MachineLoop. Based upon version in class Loop.
-    const MachineInstr *getCanonicalInductionVariable(MachineLoop *L) const;
-
-    /// getTripCount - Return a loop-invariant LLVM register indicating the
-    /// number of times the loop will be executed.  If the trip-count cannot
-    /// be determined, this return null.
-    CountValue *getTripCount(MachineLoop *L) const;
-
-    /// isInductionOperation - Return true if the instruction matches the
-    /// pattern for an opertion that defines an induction variable.
-    bool isInductionOperation(const MachineInstr *MI, unsigned IVReg) const;
+    /// Kinds of comparisons in the compare instructions.
+    struct Comparison {
+      enum Kind {
+        EQ  = 0x01,
+        NE  = 0x02,
+        L   = 0x04, // Less-than property.
+        G   = 0x08, // Greater-than property.
+        U   = 0x40, // Unsigned property.
+        LTs = L,
+        LEs = L | EQ,
+        GTs = G,
+        GEs = G | EQ,
+        LTu = L      | U,
+        LEu = L | EQ | U,
+        GTu = G      | U,
+        GEu = G | EQ | U
+      };
+
+      static Kind getSwappedComparison(Kind Cmp) {
+        assert ((!((Cmp & L) && (Cmp & G))) && "Malformed comparison operator");
+        if ((Cmp & L) || (Cmp & G))
+          return (Kind)(Cmp ^ (L|G));
+        return Cmp;
+      }
+    };
 
-    /// isInvalidOperation - Return true if the instruction is not valid within
-    /// a hardware loop.
+    /// \brief Find the register that contains the loop controlling
+    /// induction variable.
+    /// If successful, it will return true and set the \p Reg, \p IVBump
+    /// and \p IVOp arguments.  Otherwise it will return false.
+    /// The returned induction register is the register R that follows the
+    /// following induction pattern:
+    /// loop:
+    ///   R = phi ..., [ R.next, LatchBlock ]
+    ///   R.next = R + #bump
+    ///   if (R.next < #N) goto loop
+    /// IVBump is the immediate value added to R, and IVOp is the instruction
+    /// "R.next = R + #bump".
+    bool findInductionRegister(MachineLoop *L, unsigned &Reg,
+                               int64_t &IVBump, MachineInstr *&IVOp) const;
+
+    /// \brief Analyze the statements in a loop to determine if the loop
+    /// has a computable trip count and, if so, return a value that represents
+    /// the trip count expression.
+    CountValue *getLoopTripCount(MachineLoop *L,
+                                 SmallVector<MachineInstr*, 2> &OldInsts);
+
+    /// \brief Return the expression that represents the number of times
+    /// a loop iterates.  The function takes the operands that represent the
+    /// loop start value, loop end value, and induction value.  Based upon
+    /// these operands, the function attempts to compute the trip count.
+    /// If the trip count is not directly available (as an immediate value,
+    /// or a register), the function will attempt to insert computation of it
+    /// to the loop's preheader.
+    CountValue *computeCount(MachineLoop *Loop,
+                             const MachineOperand *Start,
+                             const MachineOperand *End,
+                             unsigned IVReg,
+                             int64_t IVBump,
+                             Comparison::Kind Cmp) const;
+
+    /// \brief Return true if the instruction is not valid within a hardware
+    /// loop.
     bool isInvalidLoopOperation(const MachineInstr *MI) const;
 
-    /// containsInavlidInstruction - Return true if the loop contains an
-    /// instruction that inhibits using the hardware loop.
+    /// \brief Return true if the loop contains an instruction that inhibits
+    /// using the hardware loop.
     bool containsInvalidInstruction(MachineLoop *L) const;
 
-    /// converToHardwareLoop - Given a loop, check if we can convert it to a
-    /// hardware loop.  If so, then perform the conversion and return true.
+    /// \brief Given a loop, check if we can convert it to a hardware loop.
+    /// If so, then perform the conversion and return true.
     bool convertToHardwareLoop(MachineLoop *L);
 
+    /// \brief Return true if the instruction is now dead.
+    bool isDead(const MachineInstr *MI,
+                SmallVector<MachineInstr*, 1> &DeadPhis) const;
+
+    /// \brief Remove the instruction if it is now dead.
+    void removeIfDead(MachineInstr *MI);
+
+    /// \brief Make sure that the "bump" instruction executes before the
+    /// compare.  We need that for the IV fixup, so that the compare
+    /// instruction would not use a bumped value that has not yet been
+    /// defined.  If the instructions are out of order, try to reorder them.
+    bool orderBumpCompare(MachineInstr *BumpI, MachineInstr *CmpI);
+
+    /// \brief Get the instruction that loads an immediate value into \p R,
+    /// or 0 if such an instruction does not exist.
+    MachineInstr *defWithImmediate(unsigned R);
+
+    /// \brief Get the immediate value referenced to by \p MO, either for
+    /// immediate operands, or for register operands, where the register
+    /// was defined with an immediate value.
+    int64_t getImmediate(MachineOperand &MO);
+
+    /// \brief Reset the given machine operand to now refer to a new immediate
+    /// value.  Assumes that the operand was already referencing an immediate
+    /// value, either directly, or via a register.
+    void setImmediate(MachineOperand &MO, int64_t Val);
+
+    /// \brief Fix the data flow of the induction varible.
+    /// The desired flow is: phi ---> bump -+-> comparison-in-latch.
+    ///                                     |
+    ///                                     +-> back to phi
+    /// where "bump" is the increment of the induction variable:
+    ///   iv = iv + #const.
+    /// Due to some prior code transformations, the actual flow may look
+    /// like this:
+    ///   phi -+-> bump ---> back to phi
+    ///        |
+    ///        +-> comparison-in-latch (against upper_bound-bump),
+    /// i.e. the comparison that controls the loop execution may be using
+    /// the value of the induction variable from before the increment.
+    ///
+    /// Return true if the loop's flow is the desired one (i.e. it's
+    /// either been fixed, or no fixing was necessary).
+    /// Otherwise, return false.  This can happen if the induction variable
+    /// couldn't be identified, or if the value in the latch's comparison
+    /// cannot be adjusted to reflect the post-bump value.
+    bool fixupInductionVariable(MachineLoop *L);
+
+    /// \brief Given a loop, if it does not have a preheader, create one.
+    /// Return the block that is the preheader.
+    MachineBasicBlock *createPreheaderForLoop(MachineLoop *L);
   };
 
   char HexagonHardwareLoops::ID = 0;
+#ifndef NDEBUG
+  int HexagonHardwareLoops::Counter = 0;
+#endif
 
-
-  // CountValue class - Abstraction for a trip count of a loop. A
-  // smaller vesrsion of the MachineOperand class without the concerns
-  // of changing the operand representation.
+  /// \brief Abstraction for a trip count of a loop. A smaller vesrsion
+  /// of the MachineOperand class without the concerns of changing the
+  /// operand representation.
   class CountValue {
   public:
     enum CountValueType {
@@ -119,101 +232,62 @@ namespace {
   private:
     CountValueType Kind;
     union Values {
-      unsigned RegNum;
-      int64_t ImmVal;
-      Values(unsigned r) : RegNum(r) {}
-      Values(int64_t i) : ImmVal(i) {}
+      struct {
+        unsigned Reg;
+        unsigned Sub;
+      } R;
+      unsigned ImmVal;
     } Contents;
-    bool isNegative;
 
   public:
-    CountValue(unsigned r, bool neg) : Kind(CV_Register), Contents(r),
-                                       isNegative(neg) {}
-    explicit CountValue(int64_t i) : Kind(CV_Immediate), Contents(i),
-                                     isNegative(i < 0) {}
-    CountValueType getType() const { return Kind; }
+    explicit CountValue(CountValueType t, unsigned v, unsigned u = 0) {
+      Kind = t;
+      if (Kind == CV_Register) {
+        Contents.R.Reg = v;
+        Contents.R.Sub = u;
+      } else {
+        Contents.ImmVal = v;
+      }
+    }
     bool isReg() const { return Kind == CV_Register; }
     bool isImm() const { return Kind == CV_Immediate; }
-    bool isNeg() const { return isNegative; }
 
     unsigned getReg() const {
       assert(isReg() && "Wrong CountValue accessor");
-      return Contents.RegNum;
+      return Contents.R.Reg;
     }
-    void setReg(unsigned Val) {
-      Contents.RegNum = Val;
+    unsigned getSubReg() const {
+      assert(isReg() && "Wrong CountValue accessor");
+      return Contents.R.Sub;
     }
-    int64_t getImm() const {
+    unsigned getImm() const {
       assert(isImm() && "Wrong CountValue accessor");
-      if (isNegative) {
-        return -Contents.ImmVal;
-      }
       return Contents.ImmVal;
     }
-    void setImm(int64_t Val) {
-      Contents.ImmVal = Val;
-    }
 
     void print(raw_ostream &OS, const TargetMachine *TM = 0) const {
-      if (isReg()) { OS << PrintReg(getReg()); }
-      if (isImm()) { OS << getImm(); }
-    }
-  };
-
-  struct HexagonFixupHwLoops : public MachineFunctionPass {
-  public:
-    static char ID;     // Pass identification, replacement for typeid.
-
-    HexagonFixupHwLoops() : MachineFunctionPass(ID) {}
-
-    virtual bool runOnMachineFunction(MachineFunction &MF);
-
-    const char *getPassName() const { return "Hexagon Hardware Loop Fixup"; }
-
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      AU.setPreservesCFG();
-      MachineFunctionPass::getAnalysisUsage(AU);
+      const TargetRegisterInfo *TRI = TM ? TM->getRegisterInfo() : 0;
+      if (isReg()) { OS << PrintReg(Contents.R.Reg, TRI, Contents.R.Sub); }
+      if (isImm()) { OS << Contents.ImmVal; }
     }
-
-  private:
-    /// Maximum distance between the loop instr and the basic block.
-    /// Just an estimate.
-    static const unsigned MAX_LOOP_DISTANCE = 200;
-
-    /// fixupLoopInstrs - Check the offset between each loop instruction and
-    /// the loop basic block to determine if we can use the LOOP instruction
-    /// or if we need to set the LC/SA registers explicitly.
-    bool fixupLoopInstrs(MachineFunction &MF);
-
-    /// convertLoopInstr - Add the instruction to set the LC and SA registers
-    /// explicitly.
-    void convertLoopInstr(MachineFunction &MF,
-                          MachineBasicBlock::iterator &MII,
-                          RegScavenger &RS);
-
   };
+} // end anonymous namespace
 
-  char HexagonFixupHwLoops::ID = 0;
 
-} // end anonymous namespace
+INITIALIZE_PASS_BEGIN(HexagonHardwareLoops, "hwloops",
+                      "Hexagon Hardware Loops", false, false)
+INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_PASS_END(HexagonHardwareLoops, "hwloops",
+                    "Hexagon Hardware Loops", false, false)
 
 
-/// isHardwareLoop - Returns true if the instruction is a hardware loop
-/// instruction.
+/// \brief Returns true if the instruction is a hardware loop instruction.
 static bool isHardwareLoop(const MachineInstr *MI) {
   return MI->getOpcode() == Hexagon::LOOP0_r ||
     MI->getOpcode() == Hexagon::LOOP0_i;
 }
 
-/// isCompareEquals - Returns true if the instruction is a compare equals
-/// instruction with an immediate operand.
-static bool isCompareEqualsImm(const MachineInstr *MI) {
-  return MI->getOpcode() == Hexagon::CMPEQri;
-}
-
-
-/// createHexagonHardwareLoops - Factory for creating
-/// the hardware loop phase.
 FunctionPass *llvm::createHexagonHardwareLoops() {
   return new HexagonHardwareLoops();
 }
@@ -224,45 +298,149 @@ bool HexagonHardwareLoops::runOnMachineFunction(MachineFunction &MF) {
 
   bool Changed = false;
 
-  // get the loop information
   MLI = &getAnalysis<MachineLoopInfo>();
-  // get the register information
   MRI = &MF.getRegInfo();
-  // the target specific instructio info.
-  TII = MF.getTarget().getInstrInfo();
+  MDT = &getAnalysis<MachineDominatorTree>();
+  TM  = static_cast<const HexagonTargetMachine*>(&MF.getTarget());
+  TII = static_cast<const HexagonInstrInfo*>(TM->getInstrInfo());
+  TRI = static_cast<const HexagonRegisterInfo*>(TM->getRegisterInfo());
 
   for (MachineLoopInfo::iterator I = MLI->begin(), E = MLI->end();
        I != E; ++I) {
     MachineLoop *L = *I;
-    if (!L->getParentLoop()) {
+    if (!L->getParentLoop())
       Changed |= convertToHardwareLoop(L);
-    }
   }
 
   return Changed;
 }
 
-/// getCanonicalInductionVariable - Check to see if the loop has a canonical
-/// induction variable. We check for a simple recurrence pattern - an
-/// integer recurrence that decrements by one each time through the loop and
-/// ends at zero.  If so, return the phi node that corresponds to it.
-///
-/// Based upon the similar code in LoopInfo except this code is specific to
-/// the machine.
-/// This method assumes that the IndVarSimplify pass has been run by 'opt'.
+
+bool HexagonHardwareLoops::findInductionRegister(MachineLoop *L,
+                                                 unsigned &Reg,
+                                                 int64_t &IVBump,
+                                                 MachineInstr *&IVOp
+                                                 ) const {
+  MachineBasicBlock *Header = L->getHeader();
+  MachineBasicBlock *Preheader = L->getLoopPreheader();
+  MachineBasicBlock *Latch = L->getLoopLatch();
+  if (!Header || !Preheader || !Latch)
+    return false;
+
+  // This pair represents an induction register together with an immediate
+  // value that will be added to it in each loop iteration.
+  typedef std::pair<unsigned,int64_t> RegisterBump;
+
+  // Mapping:  R.next -> (R, bump), where R, R.next and bump are derived
+  // from an induction operation
+  //   R.next = R + bump
+  // where bump is an immediate value.
+  typedef std::map<unsigned,RegisterBump> InductionMap;
+
+  InductionMap IndMap;
+
+  typedef MachineBasicBlock::instr_iterator instr_iterator;
+  for (instr_iterator I = Header->instr_begin(), E = Header->instr_end();
+       I != E && I->isPHI(); ++I) {
+    MachineInstr *Phi = &*I;
+
+    // Have a PHI instruction.  Get the operand that corresponds to the
+    // latch block, and see if is a result of an addition of form "reg+imm",
+    // where the "reg" is defined by the PHI node we are looking at.
+    for (unsigned i = 1, n = Phi->getNumOperands(); i < n; i += 2) {
+      if (Phi->getOperand(i+1).getMBB() != Latch)
+        continue;
+
+      unsigned PhiOpReg = Phi->getOperand(i).getReg();
+      MachineInstr *DI = MRI->getVRegDef(PhiOpReg);
+      unsigned UpdOpc = DI->getOpcode();
+      bool isAdd = (UpdOpc == Hexagon::ADD_ri);
+
+      if (isAdd) {
+        // If the register operand to the add is the PHI we're
+        // looking at, this meets the induction pattern.
+        unsigned IndReg = DI->getOperand(1).getReg();
+        if (MRI->getVRegDef(IndReg) == Phi) {
+          unsigned UpdReg = DI->getOperand(0).getReg();
+          int64_t V = DI->getOperand(2).getImm();
+          IndMap.insert(std::make_pair(UpdReg, std::make_pair(IndReg, V)));
+        }
+      }
+    }  // for (i)
+  }  // for (instr)
+
+  SmallVector<MachineOperand,2> Cond;
+  MachineBasicBlock *TB = 0, *FB = 0;
+  bool NotAnalyzed = TII->AnalyzeBranch(*Latch, TB, FB, Cond, false);
+  if (NotAnalyzed)
+    return false;
+
+  unsigned CSz = Cond.size();
+  assert (CSz == 1 || CSz == 2);
+  unsigned PredR = Cond[CSz-1].getReg();
+
+  MachineInstr *PredI = MRI->getVRegDef(PredR);
+  if (!PredI->isCompare())
+    return false;
+
+  unsigned CmpReg1 = 0, CmpReg2 = 0;
+  int CmpImm = 0, CmpMask = 0;
+  bool CmpAnalyzed = TII->analyzeCompare(PredI, CmpReg1, CmpReg2,
+                                         CmpMask, CmpImm);
+  // Fail if the compare was not analyzed, or it's not comparing a register
+  // with an immediate value.  Not checking the mask here, since we handle
+  // the individual compare opcodes (including CMPb) later on.
+  if (!CmpAnalyzed)
+    return false;
+
+  // Exactly one of the input registers to the comparison should be among
+  // the induction registers.
+  InductionMap::iterator IndMapEnd = IndMap.end();
+  InductionMap::iterator F = IndMapEnd;
+  if (CmpReg1 != 0) {
+    InductionMap::iterator F1 = IndMap.find(CmpReg1);
+    if (F1 != IndMapEnd)
+      F = F1;
+  }
+  if (CmpReg2 != 0) {
+    InductionMap::iterator F2 = IndMap.find(CmpReg2);
+    if (F2 != IndMapEnd) {
+      if (F != IndMapEnd)
+        return false;
+      F = F2;
+    }
+  }
+  if (F == IndMapEnd)
+    return false;
+
+  Reg = F->second.first;
+  IVBump = F->second.second;
+  IVOp = MRI->getVRegDef(F->first);
+  return true;
+}
+
+
+/// \brief Analyze the statements in a loop to determine if the loop has
+/// a computable trip count and, if so, return a value that represents
+/// the trip count expression.
 ///
-const MachineInstr
-*HexagonHardwareLoops::getCanonicalInductionVariable(MachineLoop *L) const {
+/// This function iterates over the phi nodes in the loop to check for
+/// induction variable patterns that are used in the calculation for
+/// the number of time the loop is executed.
+CountValue *HexagonHardwareLoops::getLoopTripCount(MachineLoop *L,
+                                SmallVector<MachineInstr*, 2> &OldInsts) {
   MachineBasicBlock *TopMBB = L->getTopBlock();
   MachineBasicBlock::pred_iterator PI = TopMBB->pred_begin();
   assert(PI != TopMBB->pred_end() &&
          "Loop must have more than one incoming edge!");
   MachineBasicBlock *Backedge = *PI++;
-  if (PI == TopMBB->pred_end()) return 0;  // dead loop
+  if (PI == TopMBB->pred_end())  // dead loop?
+    return 0;
   MachineBasicBlock *Incoming = *PI++;
-  if (PI != TopMBB->pred_end()) return 0;  // multiple backedges?
+  if (PI != TopMBB->pred_end())  // multiple backedges?
+    return 0;
 
-  // make sure there is one incoming and one backedge and determine which
+  // Make sure there is one incoming and one backedge and determine which
   // is which.
   if (L->contains(Incoming)) {
     if (L->contains(Backedge))
@@ -271,139 +449,433 @@ const MachineInstr
   } else if (!L->contains(Backedge))
     return 0;
 
-  // Loop over all of the PHI nodes, looking for a canonical induction variable:
-  //   - The PHI node is "reg1 = PHI reg2, BB1, reg3, BB2".
-  //   - The recurrence comes from the backedge.
-  //   - the definition is an induction operatio.n
-  for (MachineBasicBlock::iterator I = TopMBB->begin(), E = TopMBB->end();
-       I != E && I->isPHI(); ++I) {
-    const MachineInstr *MPhi = &*I;
-    unsigned DefReg = MPhi->getOperand(0).getReg();
-    for (unsigned i = 1; i != MPhi->getNumOperands(); i += 2) {
-      // Check each operand for the value from the backedge.
-      MachineBasicBlock *MBB = MPhi->getOperand(i+1).getMBB();
-      if (L->contains(MBB)) { // operands comes from the backedge
-        // Check if the definition is an induction operation.
-        const MachineInstr *DI = MRI->getVRegDef(MPhi->getOperand(i).getReg());
-        if (isInductionOperation(DI, DefReg)) {
-          return MPhi;
-        }
-      }
+  // Look for the cmp instruction to determine if we can get a useful trip
+  // count.  The trip count can be either a register or an immediate.  The
+  // location of the value depends upon the type (reg or imm).
+  MachineBasicBlock *Latch = L->getLoopLatch();
+  if (!Latch)
+    return 0;
+
+  unsigned IVReg = 0;
+  int64_t IVBump = 0;
+  MachineInstr *IVOp;
+  bool FoundIV = findInductionRegister(L, IVReg, IVBump, IVOp);
+  if (!FoundIV)
+    return 0;
+
+  MachineBasicBlock *Preheader = L->getLoopPreheader();
+
+  MachineOperand *InitialValue = 0;
+  MachineInstr *IV_Phi = MRI->getVRegDef(IVReg);
+  for (unsigned i = 1, n = IV_Phi->getNumOperands(); i < n; i += 2) {
+    MachineBasicBlock *MBB = IV_Phi->getOperand(i+1).getMBB();
+    if (MBB == Preheader)
+      InitialValue = &IV_Phi->getOperand(i);
+    else if (MBB == Latch)
+      IVReg = IV_Phi->getOperand(i).getReg();  // Want IV reg after bump.
+  }
+  if (!InitialValue)
+    return 0;
+
+  SmallVector<MachineOperand,2> Cond;
+  MachineBasicBlock *TB = 0, *FB = 0;
+  bool NotAnalyzed = TII->AnalyzeBranch(*Latch, TB, FB, Cond, false);
+  if (NotAnalyzed)
+    return 0;
+
+  MachineBasicBlock *Header = L->getHeader();
+  // TB must be non-null.  If FB is also non-null, one of them must be
+  // the header.  Otherwise, branch to TB could be exiting the loop, and
+  // the fall through can go to the header.
+  assert (TB && "Latch block without a branch?");
+  assert ((!FB || TB == Header || FB == Header) && "Branches not to header?");
+  if (!TB || (FB && TB != Header && FB != Header))
+    return 0;
+
+  // Branches of form "if (!P) ..." cause HexagonInstrInfo::AnalyzeBranch
+  // to put imm(0), followed by P in the vector Cond.
+  // If TB is not the header, it means that the "not-taken" path must lead
+  // to the header.
+  bool Negated = (Cond.size() > 1) ^ (TB != Header);
+  unsigned PredReg = Cond[Cond.size()-1].getReg();
+  MachineInstr *CondI = MRI->getVRegDef(PredReg);
+  unsigned CondOpc = CondI->getOpcode();
+
+  unsigned CmpReg1 = 0, CmpReg2 = 0;
+  int Mask = 0, ImmValue = 0;
+  bool AnalyzedCmp = TII->analyzeCompare(CondI, CmpReg1, CmpReg2,
+                                         Mask, ImmValue);
+  if (!AnalyzedCmp)
+    return 0;
+
+  // The comparison operator type determines how we compute the loop
+  // trip count.
+  OldInsts.push_back(CondI);
+  OldInsts.push_back(IVOp);
+
+  // Sadly, the following code gets information based on the position
+  // of the operands in the compare instruction.  This has to be done
+  // this way, because the comparisons check for a specific relationship
+  // between the operands (e.g. is-less-than), rather than to find out
+  // what relationship the operands are in (as on PPC).
+  Comparison::Kind Cmp;
+  bool isSwapped = false;
+  const MachineOperand &Op1 = CondI->getOperand(1);
+  const MachineOperand &Op2 = CondI->getOperand(2);
+  const MachineOperand *EndValue = 0;
+
+  if (Op1.isReg()) {
+    if (Op2.isImm() || Op1.getReg() == IVReg)
+      EndValue = &Op2;
+    else {
+      EndValue = &Op1;
+      isSwapped = true;
     }
   }
-  return 0;
-}
 
-/// getTripCount - Return a loop-invariant LLVM value indicating the
-/// number of times the loop will be executed.  The trip count can
-/// be either a register or a constant value.  If the trip-count
-/// cannot be determined, this returns null.
-///
-/// We find the trip count from the phi instruction that defines the
-/// induction variable.  We follow the links to the CMP instruction
-/// to get the trip count.
-///
-/// Based upon getTripCount in LoopInfo.
-///
-CountValue *HexagonHardwareLoops::getTripCount(MachineLoop *L) const {
-  // Check that the loop has a induction variable.
-  const MachineInstr *IV_Inst = getCanonicalInductionVariable(L);
-  if (IV_Inst == 0) return 0;
-
-  // Canonical loops will end with a 'cmpeq_ri IV, Imm',
-  //  if Imm is 0, get the count from the PHI opnd
-  //  if Imm is -M, than M is the count
-  //  Otherwise, Imm is the count
-  const MachineOperand *IV_Opnd;
-  const MachineOperand *InitialValue;
-  if (!L->contains(IV_Inst->getOperand(2).getMBB())) {
-    InitialValue = &IV_Inst->getOperand(1);
-    IV_Opnd = &IV_Inst->getOperand(3);
-  } else {
-    InitialValue = &IV_Inst->getOperand(3);
-    IV_Opnd = &IV_Inst->getOperand(1);
-  }
-
-  // Look for the cmp instruction to determine if we
-  // can get a useful trip count.  The trip count can
-  // be either a register or an immediate.  The location
-  // of the value depends upon the type (reg or imm).
-  for (MachineRegisterInfo::reg_iterator
-       RI = MRI->reg_begin(IV_Opnd->getReg()), RE = MRI->reg_end();
-       RI != RE; ++RI) {
-    IV_Opnd = &RI.getOperand();
-    const MachineInstr *MI = IV_Opnd->getParent();
-    if (L->contains(MI) && isCompareEqualsImm(MI)) {
-      const MachineOperand &MO = MI->getOperand(2);
-      assert(MO.isImm() && "IV Cmp Operand should be 0");
-      int64_t ImmVal = MO.getImm();
-
-      const MachineInstr *IV_DefInstr = MRI->getVRegDef(IV_Opnd->getReg());
-      assert(L->contains(IV_DefInstr->getParent()) &&
-             "IV definition should occurs in loop");
-      int64_t iv_value = IV_DefInstr->getOperand(2).getImm();
-
-      if (ImmVal == 0) {
-        // Make sure the induction variable changes by one on each iteration.
-        if (iv_value != 1 && iv_value != -1) {
+  if (!EndValue)
+    return 0;
+
+  switch (CondOpc) {
+    case Hexagon::CMPEQri:
+    case Hexagon::CMPEQrr:
+      Cmp = !Negated ? Comparison::EQ : Comparison::NE;
+      break;
+    case Hexagon::CMPLTrr:
+      Cmp = !Negated ? Comparison::LTs : Comparison::GEs;
+      break;
+    case Hexagon::CMPLTUrr:
+      Cmp = !Negated ? Comparison::LTu : Comparison::GEu;
+      break;
+    case Hexagon::CMPGTUri:
+    case Hexagon::CMPGTUrr:
+      Cmp = !Negated ? Comparison::GTu : Comparison::LEu;
+      break;
+    case Hexagon::CMPGTri:
+    case Hexagon::CMPGTrr:
+      Cmp = !Negated ? Comparison::GTs : Comparison::LEs;
+      break;
+    // Very limited support for byte/halfword compares.
+    case Hexagon::CMPbEQri_V4:
+    case Hexagon::CMPhEQri_V4: {
+      if (IVBump != 1)
+        return 0;
+
+      int64_t InitV, EndV;
+      // Since the comparisons are "ri", the EndValue should be an
+      // immediate.  Check it just in case.
+      assert(EndValue->isImm() && "Unrecognized latch comparison");
+      EndV = EndValue->getImm();
+      // Allow InitialValue to be a register defined with an immediate.
+      if (InitialValue->isReg()) {
+        if (!defWithImmediate(InitialValue->getReg()))
           return 0;
-        }
-        return new CountValue(InitialValue->getReg(), iv_value > 0);
+        InitV = getImmediate(*InitialValue);
       } else {
-        assert(InitialValue->isReg() && "Expecting register for init value");
-        const MachineInstr *DefInstr = MRI->getVRegDef(InitialValue->getReg());
-        if (DefInstr && DefInstr->getOpcode() == Hexagon::TFRI) {
-          int64_t count = ImmVal - DefInstr->getOperand(1).getImm();
-          if ((count % iv_value) != 0) {
-            return 0;
-          }
-          return new CountValue(count/iv_value);
-        }
+        assert(InitialValue->isImm());
+        InitV = InitialValue->getImm();
+      }
+      if (InitV >= EndV)
+        return 0;
+      if (CondOpc == Hexagon::CMPbEQri_V4) {
+        if (!isInt<8>(InitV) || !isInt<8>(EndV))
+          return 0;
+      } else {  // Hexagon::CMPhEQri_V4
+        if (!isInt<16>(InitV) || !isInt<16>(EndV))
+          return 0;
       }
+      Cmp = !Negated ? Comparison::EQ : Comparison::NE;
+      break;
     }
+    default:
+      return 0;
   }
-  return 0;
+
+  if (isSwapped)
+   Cmp = Comparison::getSwappedComparison(Cmp);
+
+  if (InitialValue->isReg()) {
+    unsigned R = InitialValue->getReg();
+    MachineBasicBlock *DefBB = MRI->getVRegDef(R)->getParent();
+    if (!MDT->properlyDominates(DefBB, Header))
+      return 0;
+    OldInsts.push_back(MRI->getVRegDef(R));
+  }
+  if (EndValue->isReg()) {
+    unsigned R = EndValue->getReg();
+    MachineBasicBlock *DefBB = MRI->getVRegDef(R)->getParent();
+    if (!MDT->properlyDominates(DefBB, Header))
+      return 0;
+  }
+
+  return computeCount(L, InitialValue, EndValue, IVReg, IVBump, Cmp);
 }
 
-/// isInductionOperation - return true if the operation is matches the
-/// pattern that defines an induction variable:
-///    add iv, c
-///
-bool
-HexagonHardwareLoops::isInductionOperation(const MachineInstr *MI,
-                                           unsigned IVReg) const {
-  return (MI->getOpcode() ==
-          Hexagon::ADD_ri && MI->getOperand(1).getReg() == IVReg);
+/// \brief Helper function that returns the expression that represents the
+/// number of times a loop iterates.  The function takes the operands that
+/// represent the loop start value, loop end value, and induction value.
+/// Based upon these operands, the function attempts to compute the trip count.
+CountValue *HexagonHardwareLoops::computeCount(MachineLoop *Loop,
+                                               const MachineOperand *Start,
+                                               const MachineOperand *End,
+                                               unsigned IVReg,
+                                               int64_t IVBump,
+                                               Comparison::Kind Cmp) const {
+  // Cannot handle comparison EQ, i.e. while (A == B).
+  if (Cmp == Comparison::EQ)
+    return 0;
+
+  // Check if either the start or end values are an assignment of an immediate.
+  // If so, use the immediate value rather than the register.
+  if (Start->isReg()) {
+    const MachineInstr *StartValInstr = MRI->getVRegDef(Start->getReg());
+    if (StartValInstr && StartValInstr->getOpcode() == Hexagon::TFRI)
+      Start = &StartValInstr->getOperand(1);
+  }
+  if (End->isReg()) {
+    const MachineInstr *EndValInstr = MRI->getVRegDef(End->getReg());
+    if (EndValInstr && EndValInstr->getOpcode() == Hexagon::TFRI)
+      End = &EndValInstr->getOperand(1);
+  }
+
+  assert (Start->isReg() || Start->isImm());
+  assert (End->isReg() || End->isImm());
+
+  bool CmpLess =     Cmp & Comparison::L;
+  bool CmpGreater =  Cmp & Comparison::G;
+  bool CmpHasEqual = Cmp & Comparison::EQ;
+
+  // Avoid certain wrap-arounds.  This doesn't detect all wrap-arounds.
+  // If loop executes while iv is "less" with the iv value going down, then
+  // the iv must wrap.
+  if (CmpLess && IVBump < 0)
+    return 0;
+  // If loop executes while iv is "greater" with the iv value going up, then
+  // the iv must wrap.
+  if (CmpGreater && IVBump > 0)
+    return 0;
+
+  if (Start->isImm() && End->isImm()) {
+    // Both, start and end are immediates.
+    int64_t StartV = Start->getImm();
+    int64_t EndV = End->getImm();
+    int64_t Dist = EndV - StartV;
+    if (Dist == 0)
+      return 0;
+
+    bool Exact = (Dist % IVBump) == 0;
+
+    if (Cmp == Comparison::NE) {
+      if (!Exact)
+        return 0;
+      if ((Dist < 0) ^ (IVBump < 0))
+        return 0;
+    }
+
+    // For comparisons that include the final value (i.e. include equality
+    // with the final value), we need to increase the distance by 1.
+    if (CmpHasEqual)
+      Dist = Dist > 0 ? Dist+1 : Dist-1;
+
+    // assert (CmpLess => Dist > 0);
+    assert ((!CmpLess || Dist > 0) && "Loop should never iterate!");
+    // assert (CmpGreater => Dist < 0);
+    assert ((!CmpGreater || Dist < 0) && "Loop should never iterate!");
+
+    // "Normalized" distance, i.e. with the bump set to +-1.
+    int64_t Dist1 = (IVBump > 0) ? (Dist +  (IVBump-1)) /   IVBump
+                               :  (-Dist + (-IVBump-1)) / (-IVBump);
+    assert (Dist1 > 0 && "Fishy thing.  Both operands have the same sign.");
+
+    uint64_t Count = Dist1;
+
+    if (Count > 0xFFFFFFFFULL)
+      return 0;
+
+    return new CountValue(CountValue::CV_Immediate, Count);
+  }
+
+  // A general case: Start and End are some values, but the actual
+  // iteration count may not be available.  If it is not, insert
+  // a computation of it into the preheader.
+
+  // If the induction variable bump is not a power of 2, quit.
+  // Othwerise we'd need a general integer division.
+  if (!isPowerOf2_64(abs(IVBump)))
+    return 0;
+
+  MachineBasicBlock *PH = Loop->getLoopPreheader();
+  assert (PH && "Should have a preheader by now");
+  MachineBasicBlock::iterator InsertPos = PH->getFirstTerminator();
+  DebugLoc DL = (InsertPos != PH->end()) ? InsertPos->getDebugLoc()
+                                         : DebugLoc();
+
+  // If Start is an immediate and End is a register, the trip count
+  // will be "reg - imm".  Hexagon's "subtract immediate" instruction
+  // is actually "reg + -imm".
+
+  // If the loop IV is going downwards, i.e. if the bump is negative,
+  // then the iteration count (computed as End-Start) will need to be
+  // negated.  To avoid the negation, just swap Start and End.
+  if (IVBump < 0) {
+    std::swap(Start, End);
+    IVBump = -IVBump;
+  }
+  // Cmp may now have a wrong direction, e.g.  LEs may now be GEs.
+  // Signedness, and "including equality" are preserved.
+
+  bool RegToImm = Start->isReg() && End->isImm(); // for (reg..imm)
+  bool RegToReg = Start->isReg() && End->isReg(); // for (reg..reg)
+
+  int64_t StartV = 0, EndV = 0;
+  if (Start->isImm())
+    StartV = Start->getImm();
+  if (End->isImm())
+    EndV = End->getImm();
+
+  int64_t AdjV = 0;
+  // To compute the iteration count, we would need this computation:
+  //   Count = (End - Start + (IVBump-1)) / IVBump
+  // or, when CmpHasEqual:
+  //   Count = (End - Start + (IVBump-1)+1) / IVBump
+  // The "IVBump-1" part is the adjustment (AdjV).  We can avoid
+  // generating an instruction specifically to add it if we can adjust
+  // the immediate values for Start or End.
+
+  if (CmpHasEqual) {
+    // Need to add 1 to the total iteration count.
+    if (Start->isImm())
+      StartV--;
+    else if (End->isImm())
+      EndV++;
+    else
+      AdjV += 1;
+  }
+
+  if (Cmp != Comparison::NE) {
+    if (Start->isImm())
+      StartV -= (IVBump-1);
+    else if (End->isImm())
+      EndV += (IVBump-1);
+    else
+      AdjV += (IVBump-1);
+  }
+
+  unsigned R = 0, SR = 0;
+  if (Start->isReg()) {
+    R = Start->getReg();
+    SR = Start->getSubReg();
+  } else {
+    R = End->getReg();
+    SR = End->getSubReg();
+  }
+  const TargetRegisterClass *RC = MRI->getRegClass(R);
+  // Hardware loops cannot handle 64-bit registers.  If it's a double
+  // register, it has to have a subregister.
+  if (!SR && RC == &Hexagon::DoubleRegsRegClass)
+    return 0;
+  const TargetRegisterClass *IntRC = &Hexagon::IntRegsRegClass;
+
+  // Compute DistR (register with the distance between Start and End).
+  unsigned DistR, DistSR;
+
+  // Avoid special case, where the start value is an imm(0).
+  if (Start->isImm() && StartV == 0) {
+    DistR = End->getReg();
+    DistSR = End->getSubReg();
+  } else {
+    const MCInstrDesc &SubD = RegToReg ? TII->get(Hexagon::SUB_rr) :
+                              (RegToImm ? TII->get(Hexagon::SUB_ri) :
+                                          TII->get(Hexagon::ADD_ri));
+    unsigned SubR = MRI->createVirtualRegister(IntRC);
+    MachineInstrBuilder SubIB =
+      BuildMI(*PH, InsertPos, DL, SubD, SubR);
+
+    if (RegToReg) {
+      SubIB.addReg(End->getReg(), 0, End->getSubReg())
+           .addReg(Start->getReg(), 0, Start->getSubReg());
+    } else if (RegToImm) {
+      SubIB.addImm(EndV)
+           .addReg(Start->getReg(), 0, Start->getSubReg());
+    } else { // ImmToReg
+      SubIB.addReg(End->getReg(), 0, End->getSubReg())
+           .addImm(-StartV);
+    }
+    DistR = SubR;
+    DistSR = 0;
+  }
+
+  // From DistR, compute AdjR (register with the adjusted distance).
+  unsigned AdjR, AdjSR;
+
+  if (AdjV == 0) {
+    AdjR = DistR;
+    AdjSR = DistSR;
+  } else {
+    // Generate CountR = ADD DistR, AdjVal
+    unsigned AddR = MRI->createVirtualRegister(IntRC);
+    const MCInstrDesc &AddD = TII->get(Hexagon::ADD_ri);
+    BuildMI(*PH, InsertPos, DL, AddD, AddR)
+      .addReg(DistR, 0, DistSR)
+      .addImm(AdjV);
+
+    AdjR = AddR;
+    AdjSR = 0;
+  }
+
+  // From AdjR, compute CountR (register with the final count).
+  unsigned CountR, CountSR;
+
+  if (IVBump == 1) {
+    CountR = AdjR;
+    CountSR = AdjSR;
+  } else {
+    // The IV bump is a power of two. Log_2(IV bump) is the shift amount.
+    unsigned Shift = Log2_32(IVBump);
+
+    // Generate NormR = LSR DistR, Shift.
+    unsigned LsrR = MRI->createVirtualRegister(IntRC);
+    const MCInstrDesc &LsrD = TII->get(Hexagon::LSR_ri);
+    BuildMI(*PH, InsertPos, DL, LsrD, LsrR)
+      .addReg(AdjR, 0, AdjSR)
+      .addImm(Shift);
+
+    CountR = LsrR;
+    CountSR = 0;
+  }
+
+  return new CountValue(CountValue::CV_Register, CountR, CountSR);
 }
 
-/// isInvalidOperation - Return true if the operation is invalid within
-/// hardware loop.
-bool
-HexagonHardwareLoops::isInvalidLoopOperation(const MachineInstr *MI) const {
+
+/// \brief Return true if the operation is invalid within hardware loop.
+bool HexagonHardwareLoops::isInvalidLoopOperation(
+      const MachineInstr *MI) const {
 
   // call is not allowed because the callee may use a hardware loop
-  if (MI->getDesc().isCall()) {
+  if (MI->getDesc().isCall())
     return true;
-  }
+
   // do not allow nested hardware loops
-  if (isHardwareLoop(MI)) {
+  if (isHardwareLoop(MI))
     return true;
-  }
+
   // check if the instruction defines a hardware loop register
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
     const MachineOperand &MO = MI->getOperand(i);
-    if (MO.isReg() && MO.isDef() &&
-        (MO.getReg() == Hexagon::LC0 || MO.getReg() == Hexagon::LC1 ||
-         MO.getReg() == Hexagon::SA0 || MO.getReg() == Hexagon::SA0)) {
+    if (!MO.isReg() || !MO.isDef())
+      continue;
+    unsigned R = MO.getReg();
+    if (R == Hexagon::LC0 || R == Hexagon::LC1 ||
+        R == Hexagon::SA0 || R == Hexagon::SA1)
       return true;
-    }
   }
   return false;
 }
 
-/// containsInvalidInstruction - Return true if the loop contains
-/// an instruction that inhibits the use of the hardware loop function.
-///
+
+/// \brief - Return true if the loop contains an instruction that inhibits
+/// the use of the hardware loop function.
 bool HexagonHardwareLoops::containsInvalidInstruction(MachineLoop *L) const {
   const std::vector<MachineBasicBlock*> Blocks = L->getBlocks();
   for (unsigned i = 0, e = Blocks.size(); i != e; ++i) {
@@ -411,58 +883,184 @@ bool HexagonHardwareLoops::containsInvalidInstruction(MachineLoop *L) const {
     for (MachineBasicBlock::iterator
            MII = MBB->begin(), E = MBB->end(); MII != E; ++MII) {
       const MachineInstr *MI = &*MII;
-      if (isInvalidLoopOperation(MI)) {
+      if (isInvalidLoopOperation(MI))
         return true;
-      }
     }
   }
   return false;
 }
 
-/// converToHardwareLoop - check if the loop is a candidate for
-/// converting to a hardware loop.  If so, then perform the
-/// transformation.
+
+/// \brief Returns true if the instruction is dead.  This was essentially
+/// copied from DeadMachineInstructionElim::isDead, but with special cases
+/// for inline asm, physical registers and instructions with side effects
+/// removed.
+bool HexagonHardwareLoops::isDead(const MachineInstr *MI,
+                             SmallVector<MachineInstr*, 1> &DeadPhis) const {
+  // Examine each operand.
+  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+    const MachineOperand &MO = MI->getOperand(i);
+    if (!MO.isReg() || !MO.isDef())
+      continue;
+
+    unsigned Reg = MO.getReg();
+    if (MRI->use_nodbg_empty(Reg))
+      continue;
+
+    typedef MachineRegisterInfo::use_nodbg_iterator use_nodbg_iterator;
+
+    // This instruction has users, but if the only user is the phi node for the
+    // parent block, and the only use of that phi node is this instruction, then
+    // this instruction is dead: both it (and the phi node) can be removed.
+    use_nodbg_iterator I = MRI->use_nodbg_begin(Reg);
+    use_nodbg_iterator End = MRI->use_nodbg_end();
+    if (llvm::next(I) != End || !I.getOperand().getParent()->isPHI())
+      return false;
+
+    MachineInstr *OnePhi = I.getOperand().getParent();
+    for (unsigned j = 0, f = OnePhi->getNumOperands(); j != f; ++j) {
+      const MachineOperand &OPO = OnePhi->getOperand(j);
+      if (!OPO.isReg() || !OPO.isDef())
+        continue;
+
+      unsigned OPReg = OPO.getReg();
+      use_nodbg_iterator nextJ;
+      for (use_nodbg_iterator J = MRI->use_nodbg_begin(OPReg);
+           J != End; J = nextJ) {
+        nextJ = llvm::next(J);
+        MachineOperand &Use = J.getOperand();
+        MachineInstr *UseMI = Use.getParent();
+
+        // If the phi node has a user that is not MI, bail...
+        if (MI != UseMI)
+          return false;
+      }
+    }
+    DeadPhis.push_back(OnePhi);
+  }
+
+  // If there are no defs with uses, the instruction is dead.
+  return true;
+}
+
+void HexagonHardwareLoops::removeIfDead(MachineInstr *MI) {
+  // This procedure was essentially copied from DeadMachineInstructionElim.
+
+  SmallVector<MachineInstr*, 1> DeadPhis;
+  if (isDead(MI, DeadPhis)) {
+    DEBUG(dbgs() << "HW looping will remove: " << *MI);
+
+    // It is possible that some DBG_VALUE instructions refer to this
+    // instruction.  Examine each def operand for such references;
+    // if found, mark the DBG_VALUE as undef (but don't delete it).
+    for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+      const MachineOperand &MO = MI->getOperand(i);
+      if (!MO.isReg() || !MO.isDef())
+        continue;
+      unsigned Reg = MO.getReg();
+      MachineRegisterInfo::use_iterator nextI;
+      for (MachineRegisterInfo::use_iterator I = MRI->use_begin(Reg),
+           E = MRI->use_end(); I != E; I = nextI) {
+        nextI = llvm::next(I);  // I is invalidated by the setReg
+        MachineOperand &Use = I.getOperand();
+        MachineInstr *UseMI = Use.getParent();
+        if (UseMI == MI)
+          continue;
+        if (Use.isDebug())
+          UseMI->getOperand(0).setReg(0U);
+        // This may also be a "instr -> phi -> instr" case which can
+        // be removed too.
+      }
+    }
+
+    MI->eraseFromParent();
+    for (unsigned i = 0; i < DeadPhis.size(); ++i)
+      DeadPhis[i]->eraseFromParent();
+  }
+}
+
+/// \brief Check if the loop is a candidate for converting to a hardware
+/// loop.  If so, then perform the transformation.
 ///
-/// This function works on innermost loops first.  A loop can
-/// be converted if it is a counting loop; either a register
-/// value or an immediate.
+/// This function works on innermost loops first.  A loop can be converted
+/// if it is a counting loop; either a register value or an immediate.
 ///
-/// The code makes several assumptions about the representation
-/// of the loop in llvm.
+/// The code makes several assumptions about the representation of the loop
+/// in llvm.
 bool HexagonHardwareLoops::convertToHardwareLoop(MachineLoop *L) {
+  // This is just for sanity.
+  assert(L->getHeader() && "Loop without a header?");
+
   bool Changed = false;
   // Process nested loops first.
-  for (MachineLoop::iterator I = L->begin(), E = L->end(); I != E; ++I) {
+  for (MachineLoop::iterator I = L->begin(), E = L->end(); I != E; ++I)
     Changed |= convertToHardwareLoop(*I);
-  }
+
   // If a nested loop has been converted, then we can't convert this loop.
-  if (Changed) {
+  if (Changed)
     return Changed;
+
+#ifndef NDEBUG
+  // Stop trying after reaching the limit (if any).
+  int Limit = HWLoopLimit;
+  if (Limit >= 0) {
+    if (Counter >= HWLoopLimit)
+      return false;
+    Counter++;
   }
-  // Are we able to determine the trip count for the loop?
-  CountValue *TripCount = getTripCount(L);
-  if (TripCount == 0) {
-    return false;
-  }
+#endif
+
   // Does the loop contain any invalid instructions?
-  if (containsInvalidInstruction(L)) {
+  if (containsInvalidInstruction(L))
     return false;
-  }
-  MachineBasicBlock *Preheader = L->getLoopPreheader();
-  // No preheader means there's not place for the loop instr.
-  if (Preheader == 0) {
+
+  // Is the induction variable bump feeding the latch condition?
+  if (!fixupInductionVariable(L))
     return false;
-  }
-  MachineBasicBlock::iterator InsertPos = Preheader->getFirstTerminator();
 
   MachineBasicBlock *LastMBB = L->getExitingBlock();
   // Don't generate hw loop if the loop has more than one exit.
-  if (LastMBB == 0) {
+  if (LastMBB == 0)
     return false;
-  }
+
   MachineBasicBlock::iterator LastI = LastMBB->getFirstTerminator();
-  if (LastI == LastMBB->end()) {
+  if (LastI == LastMBB->end())
     return false;
+
+  // Ensure the loop has a preheader: the loop instruction will be
+  // placed there.
+  bool NewPreheader = false;
+  MachineBasicBlock *Preheader = L->getLoopPreheader();
+  if (!Preheader) {
+    Preheader = createPreheaderForLoop(L);
+    if (!Preheader)
+      return false;
+    NewPreheader = true;
+  }
+  MachineBasicBlock::iterator InsertPos = Preheader->getFirstTerminator();
+
+  SmallVector<MachineInstr*, 2> OldInsts;
+  // Are we able to determine the trip count for the loop?
+  CountValue *TripCount = getLoopTripCount(L, OldInsts);
+  if (TripCount == 0)
+    return false;
+
+  // Is the trip count available in the preheader?
+  if (TripCount->isReg()) {
+    // There will be a use of the register inserted into the preheader,
+    // so make sure that the register is actually defined at that point.
+    MachineInstr *TCDef = MRI->getVRegDef(TripCount->getReg());
+    MachineBasicBlock *BBDef = TCDef->getParent();
+    if (!NewPreheader) {
+      if (!MDT->dominates(BBDef, Preheader))
+        return false;
+    } else {
+      // If we have just created a preheader, the dominator tree won't be
+      // aware of it.  Check if the definition of the register dominates
+      // the header, but is not the header itself.
+      if (!MDT->properlyDominates(BBDef, L->getHeader()))
+        return false;
+    }
   }
 
   // Determine the loop start.
@@ -470,53 +1068,53 @@ bool HexagonHardwareLoops::convertToHardwareLoop(MachineLoop *L) {
   if (L->getLoopLatch() != LastMBB) {
     // When the exit and latch are not the same, use the latch block as the
     // start.
-    // The loop start address is used only after the 1st iteration, and the loop
-    // latch may contains instrs. that need to be executed after the 1st iter.
+    // The loop start address is used only after the 1st iteration, and the
+    // loop latch may contains instrs. that need to be executed after the
+    // first iteration.
     LoopStart = L->getLoopLatch();
     // Make sure the latch is a successor of the exit, otherwise it won't work.
-    if (!LastMBB->isSuccessor(LoopStart)) {
+    if (!LastMBB->isSuccessor(LoopStart))
       return false;
-    }
   }
 
-  // Convert the loop to a hardware loop
+  // Convert the loop to a hardware loop.
   DEBUG(dbgs() << "Change to hardware loop at "; L->dump());
-  DebugLoc InsertPosDL;
+  DebugLoc DL;
   if (InsertPos != Preheader->end())
-    InsertPosDL = InsertPos->getDebugLoc();
+    DL = InsertPos->getDebugLoc();
 
   if (TripCount->isReg()) {
     // Create a copy of the loop count register.
-    MachineFunction *MF = LastMBB->getParent();
-    const TargetRegisterClass *RC =
-      MF->getRegInfo().getRegClass(TripCount->getReg());
-    unsigned CountReg = MF->getRegInfo().createVirtualRegister(RC);
-    BuildMI(*Preheader, InsertPos, InsertPosDL,
-            TII->get(TargetOpcode::COPY), CountReg).addReg(TripCount->getReg());
-    if (TripCount->isNeg()) {
-      unsigned CountReg1 = CountReg;
-      CountReg = MF->getRegInfo().createVirtualRegister(RC);
-      BuildMI(*Preheader, InsertPos, InsertPosDL,
-              TII->get(Hexagon::NEG), CountReg).addReg(CountReg1);
-    }
-
+    unsigned CountReg = MRI->createVirtualRegister(&Hexagon::IntRegsRegClass);
+    BuildMI(*Preheader, InsertPos, DL, TII->get(TargetOpcode::COPY), CountReg)
+      .addReg(TripCount->getReg(), 0, TripCount->getSubReg());
     // Add the Loop instruction to the beginning of the loop.
-    BuildMI(*Preheader, InsertPos, InsertPosDL,
-            TII->get(Hexagon::LOOP0_r)).addMBB(LoopStart).addReg(CountReg);
+    BuildMI(*Preheader, InsertPos, DL, TII->get(Hexagon::LOOP0_r))
+      .addMBB(LoopStart)
+      .addReg(CountReg);
   } else {
-    assert(TripCount->isImm() && "Expecting immedate vaule for trip count");
-    // Add the Loop immediate instruction to the beginning of the loop.
+    assert(TripCount->isImm() && "Expecting immediate value for trip count");
+    // Add the Loop immediate instruction to the beginning of the loop,
+    // if the immediate fits in the instructions.  Otherwise, we need to
+    // create a new virtual register.
     int64_t CountImm = TripCount->getImm();
-    BuildMI(*Preheader, InsertPos, InsertPosDL,
-            TII->get(Hexagon::LOOP0_i)).addMBB(LoopStart).addImm(CountImm);
+    if (!TII->isValidOffset(Hexagon::LOOP0_i, CountImm)) {
+      unsigned CountReg = MRI->createVirtualRegister(&Hexagon::IntRegsRegClass);
+      BuildMI(*Preheader, InsertPos, DL, TII->get(Hexagon::TFRI), CountReg)
+        .addImm(CountImm);
+      BuildMI(*Preheader, InsertPos, DL, TII->get(Hexagon::LOOP0_r))
+        .addMBB(LoopStart).addReg(CountReg);
+    } else
+      BuildMI(*Preheader, InsertPos, DL, TII->get(Hexagon::LOOP0_i))
+        .addMBB(LoopStart).addImm(CountImm);
   }
 
-  // Make sure the loop start always has a reference in the CFG.  We need to
-  // create a BlockAddress operand to get this mechanism to work both the
+  // Make sure the loop start always has a reference in the CFG.  We need
+  // to create a BlockAddress operand to get this mechanism to work both the
   // MachineBasicBlock and BasicBlock objects need the flag set.
   LoopStart->setHasAddressTaken();
   // This line is needed to set the hasAddressTaken flag on the BasicBlock
-  // object
+  // object.
   BlockAddress::get(const_cast<BasicBlock *>(LoopStart->getBasicBlock()));
 
   // Replace the loop branch with an endloop instruction.
@@ -529,13 +1127,12 @@ bool HexagonHardwareLoops::convertToHardwareLoop(MachineLoop *L) {
   //  - a conditional branch to the loop start.
   if (LastI->getOpcode() == Hexagon::JMP_c ||
       LastI->getOpcode() == Hexagon::JMP_cNot) {
-    // delete one and change/add an uncond. branch to out of the loop
+    // Delete one and change/add an uncond. branch to out of the loop.
     MachineBasicBlock *BranchTarget = LastI->getOperand(1).getMBB();
     LastI = LastMBB->erase(LastI);
     if (!L->contains(BranchTarget)) {
-      if (LastI != LastMBB->end()) {
-        TII->RemoveBranch(*LastMBB);
-      }
+      if (LastI != LastMBB->end())
+        LastI = LastMBB->erase(LastI);
       SmallVector<MachineOperand, 0> Cond;
       TII->InsertBranch(*LastMBB, BranchTarget, 0, Cond, LastIDL);
     }
@@ -545,110 +1142,414 @@ bool HexagonHardwareLoops::convertToHardwareLoop(MachineLoop *L) {
   }
   delete TripCount;
 
+  // The induction operation and the comparison may now be
+  // unneeded. If these are unneeded, then remove them.
+  for (unsigned i = 0; i < OldInsts.size(); ++i)
+    removeIfDead(OldInsts[i]);
+
   ++NumHWLoops;
   return true;
 }
 
-/// createHexagonFixupHwLoops - Factory for creating the hardware loop
-/// phase.
-FunctionPass *llvm::createHexagonFixupHwLoops() {
-  return new HexagonFixupHwLoops();
+
+bool HexagonHardwareLoops::orderBumpCompare(MachineInstr *BumpI,
+                                            MachineInstr *CmpI) {
+  assert (BumpI != CmpI && "Bump and compare in the same instruction?");
+
+  MachineBasicBlock *BB = BumpI->getParent();
+  if (CmpI->getParent() != BB)
+    return false;
+
+  typedef MachineBasicBlock::instr_iterator instr_iterator;
+  // Check if things are in order to begin with.
+  for (instr_iterator I = BumpI, E = BB->instr_end(); I != E; ++I)
+    if (&*I == CmpI)
+      return true;
+
+  // Out of order.
+  unsigned PredR = CmpI->getOperand(0).getReg();
+  bool FoundBump = false;
+  instr_iterator CmpIt = CmpI, NextIt = llvm::next(CmpIt);
+  for (instr_iterator I = NextIt, E = BB->instr_end(); I != E; ++I) {
+    MachineInstr *In = &*I;
+    for (unsigned i = 0, n = In->getNumOperands(); i < n; ++i) {
+      MachineOperand &MO = In->getOperand(i);
+      if (MO.isReg() && MO.isUse()) {
+        if (MO.getReg() == PredR)  // Found an intervening use of PredR.
+          return false;
+      }
+    }
+
+    if (In == BumpI) {
+      instr_iterator After = BumpI;
+      instr_iterator From = CmpI;
+      BB->splice(llvm::next(After), BB, From);
+      FoundBump = true;
+      break;
+    }
+  }
+  assert (FoundBump && "Cannot determine instruction order");
+  return FoundBump;
 }
 
-bool HexagonFixupHwLoops::runOnMachineFunction(MachineFunction &MF) {
-  DEBUG(dbgs() << "****** Hexagon Hardware Loop Fixup ******\n");
 
-  bool Changed = fixupLoopInstrs(MF);
-  return Changed;
+MachineInstr *HexagonHardwareLoops::defWithImmediate(unsigned R) {
+  MachineInstr *DI = MRI->getVRegDef(R);
+  unsigned DOpc = DI->getOpcode();
+  switch (DOpc) {
+    case Hexagon::TFRI:
+    case Hexagon::TFRI64:
+    case Hexagon::CONST32_Int_Real:
+    case Hexagon::CONST64_Int_Real:
+      return DI;
+  }
+  return 0;
 }
 
-/// fixupLoopInsts - For Hexagon, if the loop label is to far from the
-/// loop instruction then we need to set the LC0 and SA0 registers
-/// explicitly instead of using LOOP(start,count).  This function
-/// checks the distance, and generates register assignments if needed.
-///
-/// This function makes two passes over the basic blocks.  The first
-/// pass computes the offset of the basic block from the start.
-/// The second pass checks all the loop instructions.
-bool HexagonFixupHwLoops::fixupLoopInstrs(MachineFunction &MF) {
-
-  // Offset of the current instruction from the start.
-  unsigned InstOffset = 0;
-  // Map for each basic block to it's first instruction.
-  DenseMap<MachineBasicBlock*, unsigned> BlockToInstOffset;
-
-  // First pass - compute the offset of each basic block.
-  for (MachineFunction::iterator MBB = MF.begin(), MBBe = MF.end();
-       MBB != MBBe; ++MBB) {
-    BlockToInstOffset[MBB] = InstOffset;
-    InstOffset += (MBB->size() * 4);
-  }
-
-  // Second pass - check each loop instruction to see if it needs to
-  // be converted.
-  InstOffset = 0;
-  bool Changed = false;
-  RegScavenger RS;
-
-  // Loop over all the basic blocks.
-  for (MachineFunction::iterator MBB = MF.begin(), MBBe = MF.end();
-       MBB != MBBe; ++MBB) {
-    InstOffset = BlockToInstOffset[MBB];
-    RS.enterBasicBlock(MBB);
-
-    // Loop over all the instructions.
-    MachineBasicBlock::iterator MIE = MBB->end();
-    MachineBasicBlock::iterator MII = MBB->begin();
-    while (MII != MIE) {
-      if (isHardwareLoop(MII)) {
-        RS.forward(MII);
-        assert(MII->getOperand(0).isMBB() &&
-               "Expect a basic block as loop operand");
-        int diff = InstOffset - BlockToInstOffset[MII->getOperand(0).getMBB()];
-        diff = (diff > 0 ? diff : -diff);
-        if ((unsigned)diff > MAX_LOOP_DISTANCE) {
-          // Convert to explicity setting LC0 and SA0.
-          convertLoopInstr(MF, MII, RS);
-          MII = MBB->erase(MII);
-          Changed = true;
-        } else {
-          ++MII;
+
+int64_t HexagonHardwareLoops::getImmediate(MachineOperand &MO) {
+  if (MO.isImm())
+    return MO.getImm();
+  assert(MO.isReg());
+  unsigned R = MO.getReg();
+  MachineInstr *DI = defWithImmediate(R);
+  assert(DI && "Need an immediate operand");
+  // All currently supported "define-with-immediate" instructions have the
+  // actual immediate value in the operand(1).
+  int64_t v = DI->getOperand(1).getImm();
+  return v;
+}
+
+
+void HexagonHardwareLoops::setImmediate(MachineOperand &MO, int64_t Val) {
+  if (MO.isImm()) {
+    MO.setImm(Val);
+    return;
+  }
+
+  assert(MO.isReg());
+  unsigned R = MO.getReg();
+  MachineInstr *DI = defWithImmediate(R);
+  if (MRI->hasOneNonDBGUse(R)) {
+    // If R has only one use, then just change its defining instruction to
+    // the new immediate value.
+    DI->getOperand(1).setImm(Val);
+    return;
+  }
+
+  const TargetRegisterClass *RC = MRI->getRegClass(R);
+  unsigned NewR = MRI->createVirtualRegister(RC);
+  MachineBasicBlock &B = *DI->getParent();
+  DebugLoc DL = DI->getDebugLoc();
+  BuildMI(B, DI, DL, TII->get(DI->getOpcode()), NewR)
+    .addImm(Val);
+  MO.setReg(NewR);
+}
+
+
+bool HexagonHardwareLoops::fixupInductionVariable(MachineLoop *L) {
+  MachineBasicBlock *Header = L->getHeader();
+  MachineBasicBlock *Preheader = L->getLoopPreheader();
+  MachineBasicBlock *Latch = L->getLoopLatch();
+
+  if (!Header || !Preheader || !Latch)
+    return false;
+
+  // These data structures follow the same concept as the corresponding
+  // ones in findInductionRegister (where some comments are).
+  typedef std::pair<unsigned,int64_t> RegisterBump;
+  typedef std::pair<unsigned,RegisterBump> RegisterInduction;
+  typedef std::set<RegisterInduction> RegisterInductionSet;
+
+  // Register candidates for induction variables, with their associated bumps.
+  RegisterInductionSet IndRegs;
+
+  // Look for induction patterns:
+  //   vreg1 = PHI ..., [ latch, vreg2 ]
+  //   vreg2 = ADD vreg1, imm
+  typedef MachineBasicBlock::instr_iterator instr_iterator;
+  for (instr_iterator I = Header->instr_begin(), E = Header->instr_end();
+       I != E && I->isPHI(); ++I) {
+    MachineInstr *Phi = &*I;
+
+    // Have a PHI instruction.
+    for (unsigned i = 1, n = Phi->getNumOperands(); i < n; i += 2) {
+      if (Phi->getOperand(i+1).getMBB() != Latch)
+        continue;
+
+      unsigned PhiReg = Phi->getOperand(i).getReg();
+      MachineInstr *DI = MRI->getVRegDef(PhiReg);
+      unsigned UpdOpc = DI->getOpcode();
+      bool isAdd = (UpdOpc == Hexagon::ADD_ri);
+
+      if (isAdd) {
+        // If the register operand to the add/sub is the PHI we are looking
+        // at, this meets the induction pattern.
+        unsigned IndReg = DI->getOperand(1).getReg();
+        if (MRI->getVRegDef(IndReg) == Phi) {
+          unsigned UpdReg = DI->getOperand(0).getReg();
+          int64_t V = DI->getOperand(2).getImm();
+          IndRegs.insert(std::make_pair(UpdReg, std::make_pair(IndReg, V)));
         }
-      } else {
-        ++MII;
       }
-      InstOffset += 4;
+    }  // for (i)
+  }  // for (instr)
+
+  if (IndRegs.empty())
+    return false;
+
+  MachineBasicBlock *TB = 0, *FB = 0;
+  SmallVector<MachineOperand,2> Cond;
+  // AnalyzeBranch returns true if it fails to analyze branch.
+  bool NotAnalyzed = TII->AnalyzeBranch(*Latch, TB, FB, Cond, false);
+  if (NotAnalyzed)
+    return false;
+
+  // Check if the latch branch is unconditional.
+  if (Cond.empty())
+    return false;
+
+  if (TB != Header && FB != Header)
+    // The latch does not go back to the header.  Not a latch we know and love.
+    return false;
+
+  // Expecting a predicate register as a condition.  It won't be a hardware
+  // predicate register at this point yet, just a vreg.
+  // HexagonInstrInfo::AnalyzeBranch for negated branches inserts imm(0)
+  // into Cond, followed by the predicate register.  For non-negated branches
+  // it's just the register.
+  unsigned CSz = Cond.size();
+  if (CSz != 1 && CSz != 2)
+    return false;
+
+  unsigned P = Cond[CSz-1].getReg();
+  MachineInstr *PredDef = MRI->getVRegDef(P);
+
+  if (!PredDef->isCompare())
+    return false;
+
+  SmallSet<unsigned,2> CmpRegs;
+  MachineOperand *CmpImmOp = 0;
+
+  // Go over all operands to the compare and look for immediate and register
+  // operands.  Assume that if the compare has a single register use and a
+  // single immediate operand, then the register is being compared with the
+  // immediate value.
+  for (unsigned i = 0, n = PredDef->getNumOperands(); i < n; ++i) {
+    MachineOperand &MO = PredDef->getOperand(i);
+    if (MO.isReg()) {
+      // Skip all implicit references.  In one case there was:
+      //   %vreg140<def> = FCMPUGT32_rr %vreg138, %vreg139, %USR<imp-use>
+      if (MO.isImplicit())
+        continue;
+      if (MO.isUse()) {
+        unsigned R = MO.getReg();
+        if (!defWithImmediate(R)) {
+          CmpRegs.insert(MO.getReg());
+          continue;
+        }
+        // Consider the register to be the "immediate" operand.
+        if (CmpImmOp)
+          return false;
+        CmpImmOp = &MO;
+      }
+    } else if (MO.isImm()) {
+      if (CmpImmOp)    // A second immediate argument?  Confusing.  Bail out.
+        return false;
+      CmpImmOp = &MO;
     }
   }
 
-  return Changed;
+  if (CmpRegs.empty())
+    return false;
+
+  // Check if the compared register follows the order we want.  Fix if needed.
+  for (RegisterInductionSet::iterator I = IndRegs.begin(), E = IndRegs.end();
+       I != E; ++I) {
+    // This is a success.  If the register used in the comparison is one that
+    // we have identified as a bumped (updated) induction register, there is
+    // nothing to do.
+    if (CmpRegs.count(I->first))
+      return true;
+
+    // Otherwise, if the register being compared comes out of a PHI node,
+    // and has been recognized as following the induction pattern, and is
+    // compared against an immediate, we can fix it.
+    const RegisterBump &RB = I->second;
+    if (CmpRegs.count(RB.first)) {
+      if (!CmpImmOp)
+        return false;
+
+      int64_t CmpImm = getImmediate(*CmpImmOp);
+      int64_t V = RB.second;
+      if (V > 0 && CmpImm+V < CmpImm)  // Overflow (64-bit).
+        return false;
+      if (V < 0 && CmpImm+V > CmpImm)  // Overflow (64-bit).
+        return false;
+      CmpImm += V;
+      // Some forms of cmp-immediate allow u9 and s10.  Assume the worst case
+      // scenario, i.e. an 8-bit value.
+      if (CmpImmOp->isImm() && !isInt<8>(CmpImm))
+        return false;
+
+      // Make sure that the compare happens after the bump.  Otherwise,
+      // after the fixup, the compare would use a yet-undefined register.
+      MachineInstr *BumpI = MRI->getVRegDef(I->first);
+      bool Order = orderBumpCompare(BumpI, PredDef);
+      if (!Order)
+        return false;
+
+      // Finally, fix the compare instruction.
+      setImmediate(*CmpImmOp, CmpImm);
+      for (unsigned i = 0, n = PredDef->getNumOperands(); i < n; ++i) {
+        MachineOperand &MO = PredDef->getOperand(i);
+        if (MO.isReg() && MO.getReg() == RB.first) {
+          MO.setReg(I->first);
+          return true;
+        }
+      }
+    }
+  }
 
+  return false;
 }
 
-/// convertLoopInstr - convert a loop instruction to a sequence of instructions
-/// that set the lc and sa register explicitly.
-void HexagonFixupHwLoops::convertLoopInstr(MachineFunction &MF,
-                                           MachineBasicBlock::iterator &MII,
-                                           RegScavenger &RS) {
-  const TargetInstrInfo *TII = MF.getTarget().getInstrInfo();
-  MachineBasicBlock *MBB = MII->getParent();
-  DebugLoc DL = MII->getDebugLoc();
-  unsigned Scratch = RS.scavengeRegister(&Hexagon::IntRegsRegClass, MII, 0);
-
-  // First, set the LC0 with the trip count.
-  if (MII->getOperand(1).isReg()) {
-    // Trip count is a register
-    BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFCR), Hexagon::LC0)
-      .addReg(MII->getOperand(1).getReg());
+
+/// \brief Create a preheader for a given loop.
+MachineBasicBlock *HexagonHardwareLoops::createPreheaderForLoop(
+      MachineLoop *L) {
+  if (MachineBasicBlock *TmpPH = L->getLoopPreheader())
+    return TmpPH;
+
+  MachineBasicBlock *Header = L->getHeader();
+  MachineBasicBlock *Latch = L->getLoopLatch();
+  MachineFunction *MF = Header->getParent();
+  DebugLoc DL;
+
+  if (!Latch || Header->hasAddressTaken())
+    return 0;
+
+  typedef MachineBasicBlock::instr_iterator instr_iterator;
+  typedef MachineBasicBlock::pred_iterator pred_iterator;
+
+  // Verify that all existing predecessors have analyzable branches
+  // (or no branches at all).
+  typedef std::vector<MachineBasicBlock*> MBBVector;
+  MBBVector Preds(Header->pred_begin(), Header->pred_end());
+  SmallVector<MachineOperand,2> Tmp1;
+  MachineBasicBlock *TB = 0, *FB = 0;
+
+  if (TII->AnalyzeBranch(*Latch, TB, FB, Tmp1, false))
+    return 0;
+
+  for (MBBVector::iterator I = Preds.begin(), E = Preds.end(); I != E; ++I) {
+    MachineBasicBlock *PB = *I;
+    if (PB != Latch) {
+      bool NotAnalyzed = TII->AnalyzeBranch(*PB, TB, FB, Tmp1, false);
+      if (NotAnalyzed)
+        return 0;
+    }
+  }
+
+  MachineBasicBlock *NewPH = MF->CreateMachineBasicBlock();
+  MF->insert(Header, NewPH);
+
+  if (Header->pred_size() > 2) {
+    // Ensure that the header has only two predecessors: the preheader and
+    // the loop latch.  Any additional predecessors of the header should
+    // join at the newly created preheader.  Inspect all PHI nodes from the
+    // header and create appropriate corresponding PHI nodes in the preheader.
+
+    for (instr_iterator I = Header->instr_begin(), E = Header->instr_end();
+         I != E && I->isPHI(); ++I) {
+      MachineInstr *PN = &*I;
+
+      const MCInstrDesc &PD = TII->get(TargetOpcode::PHI);
+      MachineInstr *NewPN = MF->CreateMachineInstr(PD, DL);
+      NewPH->insert(NewPH->end(), NewPN);
+
+      unsigned PR = PN->getOperand(0).getReg();
+      const TargetRegisterClass *RC = MRI->getRegClass(PR);
+      unsigned NewPR = MRI->createVirtualRegister(RC);
+      NewPN->addOperand(MachineOperand::CreateReg(NewPR, true));
+
+      // Copy all non-latch operands of a header's PHI node to the newly
+      // created PHI node in the preheader.
+      for (unsigned i = 1, n = PN->getNumOperands(); i < n; i += 2) {
+        unsigned PredR = PN->getOperand(i).getReg();
+        MachineBasicBlock *PredB = PN->getOperand(i+1).getMBB();
+        if (PredB == Latch)
+          continue;
+
+        NewPN->addOperand(MachineOperand::CreateReg(PredR, false));
+        NewPN->addOperand(MachineOperand::CreateMBB(PredB));
+      }
+
+      // Remove copied operands from the old PHI node and add the value
+      // coming from the preheader's PHI.
+      for (int i = PN->getNumOperands()-2; i > 0; i -= 2) {
+        MachineBasicBlock *PredB = PN->getOperand(i+1).getMBB();
+        if (PredB != Latch) {
+          PN->RemoveOperand(i+1);
+          PN->RemoveOperand(i);
+        }
+      }
+      PN->addOperand(MachineOperand::CreateReg(NewPR, false));
+      PN->addOperand(MachineOperand::CreateMBB(NewPH));
+    }
+
   } else {
-    // Trip count is an immediate.
-    BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFRI), Scratch)
-      .addImm(MII->getOperand(1).getImm());
-    BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFCR), Hexagon::LC0)
-      .addReg(Scratch);
-  }
-  // Then, set the SA0 with the loop start address.
-  BuildMI(*MBB, MII, DL, TII->get(Hexagon::CONST32_Label), Scratch)
-    .addMBB(MII->getOperand(0).getMBB());
-  BuildMI(*MBB, MII, DL, TII->get(Hexagon::TFCR), Hexagon::SA0).addReg(Scratch);
+    assert(Header->pred_size() == 2);
+
+    // The header has only two predecessors, but the non-latch predecessor
+    // is not a preheader (e.g. it has other successors, etc.)
+    // In such a case we don't need any extra PHI nodes in the new preheader,
+    // all we need is to adjust existing PHIs in the header to now refer to
+    // the new preheader.
+    for (instr_iterator I = Header->instr_begin(), E = Header->instr_end();
+         I != E && I->isPHI(); ++I) {
+      MachineInstr *PN = &*I;
+      for (unsigned i = 1, n = PN->getNumOperands(); i < n; i += 2) {
+        MachineOperand &MO = PN->getOperand(i+1);
+        if (MO.getMBB() != Latch)
+          MO.setMBB(NewPH);
+      }
+    }
+  }
+
+  // "Reroute" the CFG edges to link in the new preheader.
+  // If any of the predecessors falls through to the header, insert a branch
+  // to the new preheader in that place.
+  SmallVector<MachineOperand,1> Tmp2;
+  SmallVector<MachineOperand,1> EmptyCond;
+
+  TB = FB = 0;
+
+  for (MBBVector::iterator I = Preds.begin(), E = Preds.end(); I != E; ++I) {
+    MachineBasicBlock *PB = *I;
+    if (PB != Latch) {
+      Tmp2.clear();
+      bool NotAnalyzed = TII->AnalyzeBranch(*PB, TB, FB, Tmp2, false);
+      (void)NotAnalyzed; // supress compiler warning
+      assert (!NotAnalyzed && "Should be analyzable!");
+      if (TB != Header && (Tmp2.empty() || FB != Header))
+        TII->InsertBranch(*PB, NewPH, 0, EmptyCond, DL);
+      PB->ReplaceUsesOfBlockWith(Header, NewPH);
+    }
+  }
+
+  // It can happen that the latch block will fall through into the header.
+  // Insert an unconditional branch to the header.
+  TB = FB = 0;
+  bool LatchNotAnalyzed = TII->AnalyzeBranch(*Latch, TB, FB, Tmp2, false);
+  (void)LatchNotAnalyzed; // supress compiler warning
+  assert (!LatchNotAnalyzed && "Should be analyzable!");
+  if (!TB && !FB)
+    TII->InsertBranch(*Latch, Header, 0, EmptyCond, DL);
+
+  // Finally, the branch from the preheader to the header.
+  TII->InsertBranch(*NewPH, Header, 0, EmptyCond, DL);
+  NewPH->addSuccessor(Header);
+
+  return NewPH;
 }
diff --git a/lib/Target/Hexagon/HexagonInstrInfo.cpp b/lib/Target/Hexagon/HexagonInstrInfo.cpp
index c067465e99..ee37deab8d 100644
--- a/lib/Target/Hexagon/HexagonInstrInfo.cpp
+++ b/lib/Target/Hexagon/HexagonInstrInfo.cpp
@@ -2461,6 +2461,9 @@ isValidOffset(const int Opcode, const int Offset) const {
   case Hexagon::LDriw_pred:
     return true;
 
+  case Hexagon::LOOP0_i:
+    return isUInt<10>(Offset);
+
   // INLINEASM is very special.
   case Hexagon::INLINEASM:
     return true;
diff --git a/test/CodeGen/Hexagon/hwloop-cleanup.ll b/test/CodeGen/Hexagon/hwloop-cleanup.ll
new file mode 100644
index 0000000000..6456ebff16
--- /dev/null
+++ b/test/CodeGen/Hexagon/hwloop-cleanup.ll
@@ -0,0 +1,86 @@
+; RUN: llc -march=hexagon -mcpu=hexagonv4 < %s | FileCheck %s
+; Check that we remove the compare and induction variable instructions
+; after generating hardware loops.
+; Bug 6685.
+
+; CHECK: loop0
+; CHECK-NOT: r{{[0-9]+}}{{.}}={{.}}add(r{{[0-9]+}},{{.}}#-1)
+; CHECK-NOT: cmp.eq
+; CHECK: endloop0
+
+define i32 @test1(i32* nocapture %b, i32 %n) nounwind readonly {
+entry:
+  %cmp1 = icmp sgt i32 %n, 0
+  br i1 %cmp1, label %for.body.preheader, label %for.end
+
+for.body.preheader:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %sum.03 = phi i32 [ %add, %for.body ], [ 0, %for.body.preheader ]
+  %arrayidx.phi = phi i32* [ %arrayidx.inc, %for.body ], [ %b, %for.body.preheader ]
+  %i.02 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
+  %0 = load i32* %arrayidx.phi, align 4
+  %add = add nsw i32 %0, %sum.03
+  %inc = add nsw i32 %i.02, 1
+  %exitcond = icmp eq i32 %inc, %n
+  %arrayidx.inc = getelementptr i32* %arrayidx.phi, i32 1
+  br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+  br label %for.end
+
+for.end:
+  %sum.0.lcssa = phi i32 [ 0, %entry ], [ %add, %for.end.loopexit ]
+  ret i32 %sum.0.lcssa
+}
+
+; This test checks that that initial loop count value is removed.
+; CHECK-NOT: ={{.}}#40
+; CHECK: loop0
+; CHECK-NOT: r{{[0-9]+}}{{.}}={{.}}add(r{{[0-9]+}},{{.}}#-1)
+; CHECK-NOT: cmp.eq
+; CHECK: endloop0
+
+define i32 @test2(i32* nocapture %b) nounwind readonly {
+entry:
+  br label %for.body
+
+for.body:
+  %sum.02 = phi i32 [ 0, %entry ], [ %add, %for.body ]
+  %arrayidx.phi = phi i32* [ %b, %entry ], [ %arrayidx.inc, %for.body ]
+  %i.01 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %0 = load i32* %arrayidx.phi, align 4
+  %add = add nsw i32 %0, %sum.02
+  %inc = add nsw i32 %i.01, 1
+  %exitcond = icmp eq i32 %inc, 40
+  %arrayidx.inc = getelementptr i32* %arrayidx.phi, i32 1
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret i32 %add
+}
+
+; This test checks that we don't remove the induction variable since it's used.
+; CHECK: loop0
+; CHECK: r{{[0-9]+}}{{.}}={{.}}add(r{{[0-9]+}},{{.}}#1)
+; CHECK-NOT: cmp.eq
+; CHECK: endloop0
+define i32 @test3(i32* nocapture %b) nounwind {
+entry:
+  br label %for.body
+
+for.body:
+  %arrayidx.phi = phi i32* [ %b, %entry ], [ %arrayidx.inc, %for.body ]
+  %i.01 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  store i32 %i.01, i32* %arrayidx.phi, align 4
+  %inc = add nsw i32 %i.01, 1
+  %exitcond = icmp eq i32 %inc, 40
+  %arrayidx.inc = getelementptr i32* %arrayidx.phi, i32 1
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret i32 0
+}
+
+
diff --git a/test/CodeGen/Hexagon/hwloop-const.ll b/test/CodeGen/Hexagon/hwloop-const.ll
new file mode 100644
index 0000000000..a621c58c63
--- /dev/null
+++ b/test/CodeGen/Hexagon/hwloop-const.ll
@@ -0,0 +1,31 @@
+; RUN: llc -march=hexagon -mcpu=hexagonv4 -O2 < %s | FileCheck %s
+; ModuleID = 'hwloop-const.c'
+target datalayout = "e-p:32:32:32-i64:64:64-i32:32:32-i16:16:16-i1:32:32-f64:64:64-f32:32:32-v64:64:64-v32:32:32-a0:0-n16:32"
+target triple = "hexagon-unknown-linux-gnu"
+
+@b = common global [25000 x i32] zeroinitializer, align 8
+@a = common global [25000 x i32] zeroinitializer, align 8
+@c = common global [25000 x i32] zeroinitializer, align 8
+
+define i32 @hwloop_bug() nounwind {
+entry:
+  br label %for.body
+
+; CHECK: endloop
+for.body:                                         ; preds = %for.body, %entry
+  %i.02 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds [25000 x i32]* @b, i32 0, i32 %i.02
+  store i32 %i.02, i32* %arrayidx, align 4, !tbaa !0
+  %arrayidx1 = getelementptr inbounds [25000 x i32]* @a, i32 0, i32 %i.02
+  store i32 %i.02, i32* %arrayidx1, align 4, !tbaa !0
+  %inc = add nsw i32 %i.02, 1
+  %exitcond = icmp eq i32 %inc, 25000
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret i32 0
+}
+
+!0 = metadata !{metadata !"int", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA"}
diff --git a/test/CodeGen/Hexagon/hwloop-dbg.ll b/test/CodeGen/Hexagon/hwloop-dbg.ll
new file mode 100644
index 0000000000..eaffa0797a
--- /dev/null
+++ b/test/CodeGen/Hexagon/hwloop-dbg.ll
@@ -0,0 +1,65 @@
+; RUN: llc < %s -march=hexagon -mcpu=hexagonv4 -O2 -disable-lsr | FileCheck %s
+; ModuleID = 'hwloop-dbg.o'
+target datalayout = "e-p:32:32:32-i64:64:64-i32:32:32-i16:16:16-i1:32:32-f64:64:64-f32:32:32-v64:64:64-v32:32:32-a0:0-n16:32"
+target triple = "hexagon"
+
+define void @foo(i32* nocapture %a, i32* nocapture %b) nounwind {
+entry:
+  tail call void @llvm.dbg.value(metadata !{i32* %a}, i64 0, metadata !13), !dbg !17
+  tail call void @llvm.dbg.value(metadata !{i32* %b}, i64 0, metadata !14), !dbg !18
+  tail call void @llvm.dbg.value(metadata !2, i64 0, metadata !15), !dbg !19
+  br label %for.body, !dbg !19
+
+for.body:                                         ; preds = %for.body, %entry
+; CHECK:     loop0(
+; CHECK-NOT: add({{r[0-9]*}}, #
+; CHECK:     endloop0
+  %arrayidx.phi = phi i32* [ %a, %entry ], [ %arrayidx.inc, %for.body ]
+  %i.02 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %b.addr.01 = phi i32* [ %b, %entry ], [ %incdec.ptr, %for.body ]
+  %incdec.ptr = getelementptr inbounds i32* %b.addr.01, i32 1, !dbg !21
+  tail call void @llvm.dbg.value(metadata !{i32* %incdec.ptr}, i64 0, metadata !14), !dbg !21
+  %0 = load i32* %b.addr.01, align 4, !dbg !21, !tbaa !23
+  store i32 %0, i32* %arrayidx.phi, align 4, !dbg !21, !tbaa !23
+  %inc = add nsw i32 %i.02, 1, !dbg !26
+  tail call void @llvm.dbg.value(metadata !{i32 %inc}, i64 0, metadata !15), !dbg !26
+  %exitcond = icmp eq i32 %inc, 10, !dbg !19
+  %arrayidx.inc = getelementptr i32* %arrayidx.phi, i32 1
+  br i1 %exitcond, label %for.end, label %for.body, !dbg !19
+
+for.end:                                          ; preds = %for.body
+  ret void, !dbg !27
+}
+
+declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 786449, i32 0, i32 12, metadata !"hwloop-dbg.c", metadata !"/usr2/kparzysz/s.hex/t", metadata !"QuIC LLVM Hexagon Clang version 6.1-pre-unknown, (git://git-hexagon-aus.quicinc.com/llvm/clang-mainline.git e9382867661454cdf44addb39430741578e9765c) (llvm/llvm-mainline.git 36412bb1fcf03ed426d4437b41198bae066675ac)", i1 true, i1 true, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ] [/usr2/kparzysz/s.hex/t/hwloop-dbg.c] [DW_LANG_C99]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"foo", metadata !"foo", metadata !"", metadata !6, i32 1, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (i32*, i32*)* @foo, null, null, metadata !11, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [foo]
+!6 = metadata !{i32 786473, metadata !"hwloop-dbg.c", metadata !"/usr2/kparzysz/s.hex/t", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!8 = metadata !{null, metadata !9, metadata !9}
+!9 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 32, i64 32, i64 0, i32 0, metadata !10} ; [ DW_TAG_pointer_type ] [line 0, size 32, align 32, offset 0] [from int]
+!10 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!11 = metadata !{metadata !12}
+!12 = metadata !{metadata !13, metadata !14, metadata !15}
+!13 = metadata !{i32 786689, metadata !5, metadata !"a", metadata !6, i32 16777217, metadata !9, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [a] [line 1]
+!14 = metadata !{i32 786689, metadata !5, metadata !"b", metadata !6, i32 33554433, metadata !9, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [b] [line 1]
+!15 = metadata !{i32 786688, metadata !16, metadata !"i", metadata !6, i32 2, metadata !10, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [i] [line 2]
+!16 = metadata !{i32 786443, metadata !5, i32 1, i32 26, metadata !6, i32 0} ; [ DW_TAG_lexical_block ] [/usr2/kparzysz/s.hex/t/hwloop-dbg.c]
+!17 = metadata !{i32 1, i32 15, metadata !5, null}
+!18 = metadata !{i32 1, i32 23, metadata !5, null}
+!19 = metadata !{i32 3, i32 8, metadata !20, null}
+!20 = metadata !{i32 786443, metadata !16, i32 3, i32 3, metadata !6, i32 1} ; [ DW_TAG_lexical_block ] [/usr2/kparzysz/s.hex/t/hwloop-dbg.c]
+!21 = metadata !{i32 4, i32 5, metadata !22, null}
+!22 = metadata !{i32 786443, metadata !20, i32 3, i32 28, metadata !6, i32 2} ; [ DW_TAG_lexical_block ] [/usr2/kparzysz/s.hex/t/hwloop-dbg.c]
+!23 = metadata !{metadata !"int", metadata !24}
+!24 = metadata !{metadata !"omnipotent char", metadata !25}
+!25 = metadata !{metadata !"Simple C/C++ TBAA"}
+!26 = metadata !{i32 3, i32 23, metadata !20, null}
+!27 = metadata !{i32 6, i32 1, metadata !16, null}
diff --git a/test/CodeGen/Hexagon/hwloop-le.ll b/test/CodeGen/Hexagon/hwloop-le.ll
new file mode 100644
index 0000000000..9c8cec7c2a
--- /dev/null
+++ b/test/CodeGen/Hexagon/hwloop-le.ll
@@ -0,0 +1,438 @@
+; RUN: llc -march=hexagon -mcpu=hexagonv4 -O3 < %s | FileCheck %s
+
+
+; CHECK: test_pos1_ir_sle
+; CHECK: loop0
+; a < b
+define void @test_pos1_ir_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 28395, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 28395, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_ir_sle
+; CHECK: loop0
+; a < b
+define void @test_pos2_ir_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 9073, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 9073, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_ir_sle
+; CHECK: loop0
+; a < b
+define void @test_pos4_ir_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 21956, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 21956, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_ir_sle
+; CHECK: loop0
+; a < b
+define void @test_pos8_ir_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 16782, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 16782, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_ir_sle
+; CHECK: loop0
+; a < b
+define void @test_pos16_ir_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 19097, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 19097, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos1_ri_sle
+; CHECK: loop0
+; a < b
+define void @test_pos1_ri_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, 14040
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp sle i32 %inc, 14040
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_ri_sle
+; CHECK: loop0
+; a < b
+define void @test_pos2_ri_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, 13710
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp sle i32 %inc, 13710
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_ri_sle
+; CHECK: loop0
+; a < b
+define void @test_pos4_ri_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, 9920
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp sle i32 %inc, 9920
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_ri_sle
+; CHECK: loop0
+; a < b
+define void @test_pos8_ri_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, 18924
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp sle i32 %inc, 18924
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_ri_sle
+; CHECK: loop0
+; a < b
+define void @test_pos16_ri_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, 11812
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp sle i32 %inc, 11812
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos1_rr_sle
+; CHECK: loop0
+; a < b
+define void @test_pos1_rr_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_rr_sle
+; CHECK: loop0
+; a < b
+define void @test_pos2_rr_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_rr_sle
+; CHECK: loop0
+; a < b
+define void @test_pos4_rr_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_rr_sle
+; CHECK: loop0
+; a < b
+define void @test_pos8_rr_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_rr_sle
+; CHECK: loop0
+; a < b
+define void @test_pos16_rr_sle(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp sle i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp sle i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
diff --git a/test/CodeGen/Hexagon/hwloop-lt.ll b/test/CodeGen/Hexagon/hwloop-lt.ll
new file mode 100644
index 0000000000..7e43733da2
--- /dev/null
+++ b/test/CodeGen/Hexagon/hwloop-lt.ll
@@ -0,0 +1,438 @@
+; RUN: llc -march=hexagon -mcpu=hexagonv4 -O3 < %s | FileCheck %s
+
+
+; CHECK: test_pos1_ir_slt
+; CHECK: loop0
+; a < b
+define void @test_pos1_ir_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 8531, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 8531, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_ir_slt
+; CHECK: loop0
+; a < b
+define void @test_pos2_ir_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 9152, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 9152, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_ir_slt
+; CHECK: loop0
+; a < b
+define void @test_pos4_ir_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 18851, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 18851, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_ir_slt
+; CHECK: loop0
+; a < b
+define void @test_pos8_ir_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 25466, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 25466, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_ir_slt
+; CHECK: loop0
+; a < b
+define void @test_pos16_ir_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 9295, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 9295, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos1_ri_slt
+; CHECK: loop0
+; a < b
+define void @test_pos1_ri_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 31236
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp slt i32 %inc, 31236
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_ri_slt
+; CHECK: loop0
+; a < b
+define void @test_pos2_ri_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 22653
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp slt i32 %inc, 22653
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_ri_slt
+; CHECK: loop0
+; a < b
+define void @test_pos4_ri_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 1431
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp slt i32 %inc, 1431
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_ri_slt
+; CHECK: loop0
+; a < b
+define void @test_pos8_ri_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 22403
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp slt i32 %inc, 22403
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_ri_slt
+; CHECK: loop0
+; a < b
+define void @test_pos16_ri_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 21715
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp slt i32 %inc, 21715
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos1_rr_slt
+; CHECK: loop0
+; a < b
+define void @test_pos1_rr_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_rr_slt
+; CHECK: loop0
+; a < b
+define void @test_pos2_rr_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_rr_slt
+; CHECK: loop0
+; a < b
+define void @test_pos4_rr_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_rr_slt
+; CHECK: loop0
+; a < b
+define void @test_pos8_rr_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_rr_slt
+; CHECK: loop0
+; a < b
+define void @test_pos16_rr_slt(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp slt i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
diff --git a/test/CodeGen/Hexagon/hwloop-lt1.ll b/test/CodeGen/Hexagon/hwloop-lt1.ll
new file mode 100644
index 0000000000..cf5874011e
--- /dev/null
+++ b/test/CodeGen/Hexagon/hwloop-lt1.ll
@@ -0,0 +1,32 @@
+; RUN: llc -march=hexagon -mcpu=hexagonv4 < %s | FileCheck %s
+; Check that we generate a hardware loop instruction.
+; CHECK: endloop0
+
+@A = common global [400 x i8] zeroinitializer, align 8
+@B = common global [400 x i8] zeroinitializer, align 8
+@C = common global [400 x i8] zeroinitializer, align 8
+
+define void @run() nounwind {
+entry:
+  br label %polly.loop_body
+
+polly.loop_after:                                 ; preds = %polly.loop_body
+  ret void
+
+polly.loop_body:                                  ; preds = %entry, %polly.loop_body
+  %polly.loopiv16 = phi i32 [ 0, %entry ], [ %polly.next_loopiv, %polly.loop_body ]
+  %polly.next_loopiv = add i32 %polly.loopiv16, 4
+  %p_vector_iv14 = or i32 %polly.loopiv16, 1
+  %p_vector_iv3 = add i32 %p_vector_iv14, 1
+  %p_vector_iv415 = or i32 %polly.loopiv16, 3
+  %p_arrayidx = getelementptr [400 x i8]* @A, i32 0, i32 %polly.loopiv16
+  %p_arrayidx5 = getelementptr [400 x i8]* @A, i32 0, i32 %p_vector_iv14
+  %p_arrayidx6 = getelementptr [400 x i8]* @A, i32 0, i32 %p_vector_iv3
+  %p_arrayidx7 = getelementptr [400 x i8]* @A, i32 0, i32 %p_vector_iv415
+  store i8 123, i8* %p_arrayidx, align 1
+  store i8 123, i8* %p_arrayidx5, align 1
+  store i8 123, i8* %p_arrayidx6, align 1
+  store i8 123, i8* %p_arrayidx7, align 1
+  %0 = icmp slt i32 %polly.next_loopiv, 400
+  br i1 %0, label %polly.loop_body, label %polly.loop_after
+}
diff --git a/test/CodeGen/Hexagon/hwloop-ne.ll b/test/CodeGen/Hexagon/hwloop-ne.ll
new file mode 100644
index 0000000000..bceef2a169
--- /dev/null
+++ b/test/CodeGen/Hexagon/hwloop-ne.ll
@@ -0,0 +1,438 @@
+; RUN: llc -march=hexagon -mcpu=hexagonv4 -O3 < %s | FileCheck %s
+
+
+; CHECK: test_pos1_ir_ne
+; CHECK: loop0
+; a < b
+define void @test_pos1_ir_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 32623, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 32623, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_ir_ne
+; CHECK: loop0
+; a < b
+define void @test_pos2_ir_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 29554, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 29554, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_ir_ne
+; CHECK: loop0
+; a < b
+define void @test_pos4_ir_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 15692, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 15692, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_ir_ne
+; CHECK: loop0
+; a < b
+define void @test_pos8_ir_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 10449, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 10449, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_ir_ne
+; CHECK: loop0
+; a < b
+define void @test_pos16_ir_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 32087, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ 32087, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos1_ri_ne
+; CHECK: loop0
+; a < b
+define void @test_pos1_ri_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 3472
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp ne i32 %inc, 3472
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_ri_ne
+; CHECK: loop0
+; a < b
+define void @test_pos2_ri_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 8730
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp ne i32 %inc, 8730
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_ri_ne
+; CHECK: loop0
+; a < b
+define void @test_pos4_ri_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 1493
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp ne i32 %inc, 1493
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_ri_ne
+; CHECK: loop0
+; a < b
+define void @test_pos8_ri_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 1706
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp ne i32 %inc, 1706
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_ri_ne
+; CHECK: loop0
+; a < b
+define void @test_pos16_ri_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, 1886
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp ne i32 %inc, 1886
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos1_rr_ne
+; CHECK: loop0
+; a < b
+define void @test_pos1_rr_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 1
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos2_rr_ne
+; CHECK: loop0
+; a < b
+define void @test_pos2_rr_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 2
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos4_rr_ne
+; CHECK: loop0
+; a < b
+define void @test_pos4_rr_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 4
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos8_rr_ne
+; CHECK: loop0
+; a < b
+define void @test_pos8_rr_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 8
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+
+; CHECK: test_pos16_rr_ne
+; CHECK: loop0
+; a < b
+define void @test_pos16_rr_ne(i8* nocapture %p, i32 %a, i32 %b) nounwind {
+entry:
+  %cmp3 = icmp slt i32 %a, %b
+  br i1 %cmp3, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %i.04 = phi i32 [ %a, %for.body.lr.ph ], [ %inc, %for.body ]
+  %arrayidx = getelementptr inbounds i8* %p, i32 %i.04
+  %0 = load i8* %arrayidx, align 1
+  %conv = zext i8 %0 to i32
+  %add = add nsw i32 %conv, 1
+  %conv1 = trunc i32 %add to i8
+  store i8 %conv1, i8* %arrayidx, align 1
+  %inc = add nsw i32 %i.04, 16
+  %cmp = icmp ne i32 %inc, %b
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  ret void
+}
+
+
+