misched: Use the TargetSchedModel interface wherever possible.

Allows the new machine model to be used for NumMicroOps and OutputLatency.

Allows the HazardRecognizer to be disabled along with itineraries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165603 91177308-0d34-0410-b5e6-96231b3b80d8

12 files changed, 126 insertions, 115 deletions

diff --git a/include/llvm/CodeGen/MachineScheduler.h b/include/llvm/CodeGen/MachineScheduler.h
index d88f3fc..93990e1 100644
--- a/include/llvm/CodeGen/MachineScheduler.h
+++ b/include/llvm/CodeGen/MachineScheduler.h
@@ -31,7 +31,6 @@
 #include "llvm/CodeGen/RegisterPressure.h"
 #include "llvm/CodeGen/ScheduleDAGInstrs.h"
 #include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/MC/MCInstrItineraries.h"
 
 namespace llvm {
 
@@ -278,19 +277,6 @@ public:
     return RegionCriticalPSets;
   }
 
-  /// getIssueWidth - Return the max instructions per scheduling group.
-  unsigned getIssueWidth() const {
-    return (InstrItins && InstrItins->SchedModel)
-      ? InstrItins->SchedModel->IssueWidth : 1;
-  }
-
-  /// getNumMicroOps - Return the number of issue slots required for this MI.
-  unsigned getNumMicroOps(MachineInstr *MI) const {
-    if (!InstrItins) return 1;
-    int UOps = InstrItins->getNumMicroOps(MI->getDesc().getSchedClass());
-    return (UOps >= 0) ? UOps : TII->getNumMicroOps(InstrItins, MI);
-  }
-
 protected:
   // Top-Level entry points for the schedule() driver...
 
diff --git a/include/llvm/CodeGen/ScheduleDAG.h b/include/llvm/CodeGen/ScheduleDAG.h
index 744e2ee..05b74b0 100644
--- a/include/llvm/CodeGen/ScheduleDAG.h
+++ b/include/llvm/CodeGen/ScheduleDAG.h
@@ -570,11 +570,6 @@ namespace llvm {
     unsigned VerifyScheduledDAG(bool isBottomUp);
 #endif
 
-  protected:
-    /// ComputeLatency - Compute node latency.
-    ///
-    virtual void computeLatency(SUnit *SU) = 0;
-
   private:
     // Return the MCInstrDesc of this SDNode or NULL.
     const MCInstrDesc *getNodeDesc(const SDNode *Node) const;
diff --git a/include/llvm/CodeGen/ScheduleDAGInstrs.h b/include/llvm/CodeGen/ScheduleDAGInstrs.h
index 4d8f7a3..b4496a0 100644
--- a/include/llvm/CodeGen/ScheduleDAGInstrs.h
+++ b/include/llvm/CodeGen/ScheduleDAGInstrs.h
@@ -111,7 +111,6 @@ namespace llvm {
     const MachineLoopInfo &MLI;
     const MachineDominatorTree &MDT;
     const MachineFrameInfo *MFI;
-    const InstrItineraryData *InstrItins;
 
     /// Live Intervals provides reaching defs in preRA scheduling.
     LiveIntervals *LIS;
@@ -187,6 +186,9 @@ namespace llvm {
 
     virtual ~ScheduleDAGInstrs() {}
 
+    /// \brief Get the machine model for instruction scheduling.
+    const TargetSchedModel *getSchedModel() const { return &SchedModel; }
+
     /// begin - Return an iterator to the top of the current scheduling region.
     MachineBasicBlock::iterator begin() const { return RegionBegin; }
 
@@ -227,10 +229,6 @@ namespace llvm {
     /// used by instructions in the fallthrough block.
     void addSchedBarrierDeps();
 
-    /// computeLatency - Compute node latency.
-    ///
-    virtual void computeLatency(SUnit *SU);
-
     /// schedule - Order nodes according to selected style, filling
     /// in the Sequence member.
     ///
diff --git a/include/llvm/CodeGen/TargetSchedule.h b/include/llvm/CodeGen/TargetSchedule.h
index 3adbe7d..3c55f1c 100644
--- a/include/llvm/CodeGen/TargetSchedule.h
+++ b/include/llvm/CodeGen/TargetSchedule.h
@@ -55,12 +55,29 @@ public:
   /// latency properties, but separate from the per-cycle itinerary data.
   bool hasInstrSchedModel() const;
 
+  const MCSchedModel *getMCSchedModel() const { return &SchedModel; }
+
   /// \brief Return true if this machine model includes cycle-to-cycle itinerary
   /// data.
   ///
   /// This models scheduling at each stage in the processor pipeline.
   bool hasInstrItineraries() const;
 
+  const InstrItineraryData *getInstrItineraries() const {
+    if (hasInstrItineraries())
+      return &InstrItins;
+    return 0;
+  }
+
+  /// \brief Identify the processor corresponding to the current subtarget.
+  unsigned getProcessorID() const { return SchedModel.getProcessorID(); }
+
+  /// \brief Maximum number of micro-ops that may be scheduled per cycle.
+  unsigned getIssueWidth() const { return SchedModel.IssueWidth; }
+
+  /// \brief Return the number of issue slots required for this MI.
+  unsigned getNumMicroOps(MachineInstr *MI) const;
+
   /// \brief Compute operand latency based on the available machine model.
   ///
   /// Computes and return the latency of the given data dependent def and use
@@ -82,11 +99,12 @@ public:
   /// occasionally useful to help estimate instruction cost.
   unsigned computeInstrLatency(const MachineInstr *MI) const;
 
-  /// \brief Identify the processor corresponding to the current subtarget.
-  unsigned getProcessorID() const { return SchedModel.getProcessorID(); }
+  /// \brief Output dependency latency of a pair of defs of the same register.
+  ///
+  /// This is typically one cycle.
+  unsigned computeOutputLatency(const MachineInstr *DefMI, unsigned DefIdx,
+                                const MachineInstr *DepMI) const;
 
-  /// \brief Maximum number of micro-ops that may be scheduled per cycle.
-  unsigned getIssueWidth() const { return SchedModel.IssueWidth; }
 
 private:
   /// getDefLatency is a helper for computeOperandLatency. Return the
diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h
index c5c5a7a..4570813 100644
--- a/include/llvm/Target/TargetInstrInfo.h
+++ b/include/llvm/Target/TargetInstrInfo.h
@@ -801,15 +801,6 @@ public:
                                  const MachineInstr *UseMI, unsigned UseIdx,
                                  bool FindMin = false) const;
 
-  /// getOutputLatency - Compute and return the output dependency latency of a
-  /// a given pair of defs which both target the same register. This is usually
-  /// one.
-  virtual unsigned getOutputLatency(const InstrItineraryData *ItinData,
-                                    const MachineInstr *DefMI, unsigned DefIdx,
-                                    const MachineInstr *DepMI) const {
-    return 1;
-  }
-
   /// getInstrLatency - Compute the instruction latency of a given instruction.
   /// If the instruction has higher cost when predicated, it's returned via
   /// PredCost.
diff --git a/lib/CodeGen/MachineScheduler.cpp b/lib/CodeGen/MachineScheduler.cpp
index 27c1a67..11a7d47 100644
--- a/lib/CodeGen/MachineScheduler.cpp
+++ b/lib/CodeGen/MachineScheduler.cpp
@@ -652,6 +652,7 @@ class ConvergingScheduler : public MachineSchedStrategy {
   /// of "hazards" and other interlocks at the current cycle.
   struct SchedBoundary {
     ScheduleDAGMI *DAG;
+    const TargetSchedModel *SchedModel;
 
     ReadyQueue Available;
     ReadyQueue Pending;
@@ -671,13 +672,18 @@ class ConvergingScheduler : public MachineSchedStrategy {
     /// Pending queues extend the ready queues with the same ID and the
     /// PendingFlag set.
     SchedBoundary(unsigned ID, const Twine &Name):
-      DAG(0), Available(ID, Name+".A"),
+      DAG(0), SchedModel(0), Available(ID, Name+".A"),
       Pending(ID << ConvergingScheduler::LogMaxQID, Name+".P"),
       CheckPending(false), HazardRec(0), CurrCycle(0), IssueCount(0),
       MinReadyCycle(UINT_MAX), MaxMinLatency(0) {}
 
     ~SchedBoundary() { delete HazardRec; }
 
+    void init(ScheduleDAGMI *dag, const TargetSchedModel *smodel) {
+      DAG = dag;
+      SchedModel = smodel;
+    }
+
     bool isTop() const {
       return Available.getID() == ConvergingScheduler::TopQID;
     }
@@ -698,6 +704,7 @@ class ConvergingScheduler : public MachineSchedStrategy {
   };
 
   ScheduleDAGMI *DAG;
+  const TargetSchedModel *SchedModel;
   const TargetRegisterInfo *TRI;
 
   // State of the top and bottom scheduled instruction boundaries.
@@ -713,7 +720,7 @@ public:
   };
 
   ConvergingScheduler():
-    DAG(0), TRI(0), Top(TopQID, "TopQ"), Bot(BotQID, "BotQ") {}
+    DAG(0), SchedModel(0), TRI(0), Top(TopQID, "TopQ"), Bot(BotQID, "BotQ") {}
 
   virtual void initialize(ScheduleDAGMI *dag);
 
@@ -740,13 +747,15 @@ protected:
 
 void ConvergingScheduler::initialize(ScheduleDAGMI *dag) {
   DAG = dag;
+  SchedModel = DAG->getSchedModel();
   TRI = DAG->TRI;
-  Top.DAG = dag;
-  Bot.DAG = dag;
+  Top.init(DAG, SchedModel);
+  Bot.init(DAG, SchedModel);
 
-  // Initialize the HazardRecognizers.
+  // Initialize the HazardRecognizers. If itineraries don't exist, are empty, or
+  // are disabled, then these HazardRecs will be disabled.
+  const InstrItineraryData *Itin = SchedModel->getInstrItineraries();
   const TargetMachine &TM = DAG->MF.getTarget();
-  const InstrItineraryData *Itin = TM.getInstrItineraryData();
   Top.HazardRec = TM.getInstrInfo()->CreateTargetMIHazardRecognizer(Itin, DAG);
   Bot.HazardRec = TM.getInstrInfo()->CreateTargetMIHazardRecognizer(Itin, DAG);
 
@@ -807,7 +816,8 @@ bool ConvergingScheduler::SchedBoundary::checkHazard(SUnit *SU) {
   if (HazardRec->isEnabled())
     return HazardRec->getHazardType(SU) != ScheduleHazardRecognizer::NoHazard;
 
-  if (IssueCount + DAG->getNumMicroOps(SU->getInstr()) > DAG->getIssueWidth())
+  unsigned uops = SchedModel->getNumMicroOps(SU->getInstr());
+  if (IssueCount + uops > SchedModel->getIssueWidth())
     return true;
 
   return false;
@@ -828,7 +838,7 @@ void ConvergingScheduler::SchedBoundary::releaseNode(SUnit *SU,
 
 /// Move the boundary of scheduled code by one cycle.
 void ConvergingScheduler::SchedBoundary::bumpCycle() {
-  unsigned Width = DAG->getIssueWidth();
+  unsigned Width = SchedModel->getIssueWidth();
   IssueCount = (IssueCount <= Width) ? 0 : IssueCount - Width;
 
   assert(MinReadyCycle < UINT_MAX && "MinReadyCycle uninitialized");
@@ -866,8 +876,8 @@ void ConvergingScheduler::SchedBoundary::bumpNode(SUnit *SU) {
   }
   // Check the instruction group dispatch limit.
   // TODO: Check if this SU must end a dispatch group.
-  IssueCount += DAG->getNumMicroOps(SU->getInstr());
-  if (IssueCount >= DAG->getIssueWidth()) {
+  IssueCount += SchedModel->getNumMicroOps(SU->getInstr());
+  if (IssueCount >= SchedModel->getIssueWidth()) {
     DEBUG(dbgs() << "*** Max instrs at cycle " << CurrCycle << '\n');
     bumpCycle();
   }
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index d1ea42d..aa45a68 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -44,8 +44,7 @@ ScheduleDAGInstrs::ScheduleDAGInstrs(MachineFunction &mf,
                                      const MachineDominatorTree &mdt,
                                      bool IsPostRAFlag,
                                      LiveIntervals *lis)
-  : ScheduleDAG(mf), MLI(mli), MDT(mdt), MFI(mf.getFrameInfo()),
-    InstrItins(mf.getTarget().getInstrItineraryData()), LIS(lis),
+  : ScheduleDAG(mf), MLI(mli), MDT(mdt), MFI(mf.getFrameInfo()), LIS(lis),
     IsPostRA(IsPostRAFlag), CanHandleTerminators(false), FirstDbgValue(0) {
   assert((IsPostRA || LIS) && "PreRA scheduling requires LiveIntervals");
   DbgValues.clear();
@@ -292,8 +291,8 @@ void ScheduleDAGInstrs::addPhysRegDeps(SUnit *SU, unsigned OperIdx) {
         if (Kind == SDep::Anti)
           DefSU->addPred(SDep(SU, Kind, 0, /*Reg=*/*Alias));
         else {
-          unsigned AOLat = TII->getOutputLatency(InstrItins, MI, OperIdx,
-                                                 DefSU->getInstr());
+          unsigned AOLat =
+            SchedModel.computeOutputLatency(MI, OperIdx, DefSU->getInstr());
           DefSU->addPred(SDep(SU, Kind, AOLat, /*Reg=*/*Alias));
         }
       }
@@ -363,8 +362,8 @@ void ScheduleDAGInstrs::addVRegDefDeps(SUnit *SU, unsigned OperIdx) {
   else {
     SUnit *DefSU = DefI->SU;
     if (DefSU != SU && DefSU != &ExitSU) {
-      unsigned OutLatency = TII->getOutputLatency(InstrItins, MI, OperIdx,
-                                                  DefSU->getInstr());
+      unsigned OutLatency =
+        SchedModel.computeOutputLatency(MI, OperIdx, DefSU->getInstr());
       DefSU->addPred(SDep(SU, SDep::Output, OutLatency, Reg));
     }
     DefI->SU = SU;
@@ -650,7 +649,7 @@ void ScheduleDAGInstrs::initSUnits() {
     SU->isCommutable = MI->isCommutable();
 
     // Assign the Latency field of SU using target-provided information.
-    computeLatency(SU);
+    SU->Latency = SchedModel.computeInstrLatency(SU->getInstr());
   }
 }
 
@@ -911,21 +910,6 @@ void ScheduleDAGInstrs::buildSchedGraph(AliasAnalysis *AA,
   PendingLoads.clear();
 }
 
-void ScheduleDAGInstrs::computeLatency(SUnit *SU) {
-  // Compute the latency for the node. We only provide a default for missing
-  // itineraries. Empty itineraries still have latency properties.
-  if (!InstrItins) {
-    SU->Latency = 1;
-
-    // Simplistic target-independent heuristic: assume that loads take
-    // extra time.
-    if (SU->getInstr()->mayLoad())
-      SU->Latency += 2;
-  } else {
-    SU->Latency = TII->getInstrLatency(InstrItins, SU->getInstr());
-  }
-}
-
 void ScheduleDAGInstrs::dumpNode(const SUnit *SU) const {
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
   SU->getInstr()->dump();
diff --git a/lib/CodeGen/TargetSchedule.cpp b/lib/CodeGen/TargetSchedule.cpp
index cf9d059..edf6815 100644
--- a/lib/CodeGen/TargetSchedule.cpp
+++ b/lib/CodeGen/TargetSchedule.cpp
@@ -14,6 +14,7 @@
 
 #include "llvm/CodeGen/TargetSchedule.h"
 #include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
 #include "llvm/Support/CommandLine.h"
@@ -44,6 +45,17 @@ void TargetSchedModel::init(const MCSchedModel &sm,
   STI->initInstrItins(InstrItins);
 }
 
+unsigned TargetSchedModel::getNumMicroOps(MachineInstr *MI) const {
+  if (hasInstrItineraries()) {
+    int UOps = InstrItins.getNumMicroOps(MI->getDesc().getSchedClass());
+    return (UOps >= 0) ? UOps : TII->getNumMicroOps(&InstrItins, MI);
+  }
+  if (hasInstrSchedModel())
+    return resolveSchedClass(MI)->NumMicroOps;
+
+  return 1;
+}
+
 /// If we can determine the operand latency from the def only, without machine
 /// model or itinerary lookup, do so. Otherwise return -1.
 int TargetSchedModel::getDefLatency(const MachineInstr *DefMI,
@@ -209,3 +221,40 @@ unsigned TargetSchedModel::computeInstrLatency(const MachineInstr *MI) const {
   }
   return TII->defaultDefLatency(&SchedModel, MI);
 }
+
+unsigned TargetSchedModel::
+computeOutputLatency(const MachineInstr *DefMI, unsigned DefOperIdx,
+                     const MachineInstr *DepMI) const {
+  // MinLatency == -1 is for in-order processors that always have unit
+  // MinLatency. MinLatency > 0 is for in-order processors with varying min
+  // latencies, but since this is not a RAW dep, we always use unit latency.
+  if (SchedModel.MinLatency != 0)
+    return 1;
+
+  // MinLatency == 0 indicates an out-of-order processor that can dispatch
+  // WAW dependencies in the same cycle.
+
+  // Treat predication as a data dependency for out-of-order cpus. In-order
+  // cpus do not need to treat predicated writes specially.
+  //
+  // TODO: The following hack exists because predication passes do not
+  // correctly append imp-use operands, and readsReg() strangely returns false
+  // for predicated defs.
+  unsigned Reg = DefMI->getOperand(DefOperIdx).getReg();
+  const MachineFunction &MF = *DefMI->getParent()->getParent();
+  const TargetRegisterInfo *TRI = MF.getTarget().getRegisterInfo();
+  if (!DepMI->readsRegister(Reg, TRI) && TII->isPredicated(DepMI))
+    return computeInstrLatency(DefMI);
+
+  // If we have a per operand scheduling model, check if this def is writing
+  // an unbuffered resource. If so, it treated like an in-order cpu.
+  if (hasInstrSchedModel()) {
+    const MCSchedClassDesc *SCDesc = resolveSchedClass(DefMI);
+    for (const MCWriteProcResEntry *PRI = STI->getWriteProcResBegin(SCDesc),
+           *PRE = STI->getWriteProcResEnd(SCDesc); PRI != PRE; ++PRI) {
+      if (!SchedModel.getProcResource(PRI->ProcResourceIdx)->IsBuffered)
+        return 1;
+    }
+  }
+  return 0;
+}
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 13b2a3e..b5c6159 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -3550,18 +3550,6 @@ ARMBaseInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
   return Latency;
 }
 
-unsigned
-ARMBaseInstrInfo::getOutputLatency(const InstrItineraryData *ItinData,
-                                   const MachineInstr *DefMI, unsigned DefIdx,
-                                   const MachineInstr *DepMI) const {
-  unsigned Reg = DefMI->getOperand(DefIdx).getReg();
-  if (DepMI->readsRegister(Reg, &getRegisterInfo()) || !isPredicated(DepMI))
-    return 1;
-
-  // If the second MI is predicated, then there is an implicit use dependency.
-  return getInstrLatency(ItinData, DefMI);
-}
-
 unsigned ARMBaseInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
                                            const MachineInstr *MI,
                                            unsigned *PredCost) const {
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.h b/lib/Target/ARM/ARMBaseInstrInfo.h
index 8f4f47b..6f38e35 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.h
+++ b/lib/Target/ARM/ARMBaseInstrInfo.h
@@ -229,10 +229,6 @@ public:
                         SDNode *DefNode, unsigned DefIdx,
                         SDNode *UseNode, unsigned UseIdx) const;
 
-  virtual unsigned getOutputLatency(const InstrItineraryData *ItinData,
-                                    const MachineInstr *DefMI, unsigned DefIdx,
-                                    const MachineInstr *DepMI) const;
-
   /// VFP/NEON execution domains.
   std::pair<uint16_t, uint16_t>
   getExecutionDomain(const MachineInstr *MI) const;
diff --git a/lib/Target/Hexagon/HexagonMachineScheduler.cpp b/lib/Target/Hexagon/HexagonMachineScheduler.cpp
index 1db6f5e..ca52570 100644
--- a/lib/Target/Hexagon/HexagonMachineScheduler.cpp
+++ b/lib/Target/Hexagon/HexagonMachineScheduler.cpp
@@ -128,7 +128,7 @@ bool VLIWResourceModel::reserveResources(SUnit *SU) {
 
   // If packet is now full, reset the state so in the next cycle
   // we start fresh.
-  if (Packet.size() >= InstrItins->SchedModel->IssueWidth) {
+  if (Packet.size() >= SchedModel->getIssueWidth()) {
     ResourcesModel->clearResources();
     Packet.clear();
     TotalPackets++;
@@ -186,18 +186,20 @@ void VLIWMachineScheduler::schedule() {
 
 void ConvergingVLIWScheduler::initialize(ScheduleDAGMI *dag) {
   DAG = static_cast<VLIWMachineScheduler*>(dag);
+  SchedModel = DAG->getSchedModel();
   TRI = DAG->TRI;
-  Top.DAG = DAG;
-  Bot.DAG = DAG;
+  Top.init(DAG, SchedModel);
+  Bot.init(DAG, SchedModel);
 
-  // Initialize the HazardRecognizers.
+  // Initialize the HazardRecognizers. If itineraries don't exist, are empty, or
+  // are disabled, then these HazardRecs will be disabled.
+  const InstrItineraryData *Itin = DAG->getSchedModel()->getInstrItineraries();
   const TargetMachine &TM = DAG->MF.getTarget();
-  const InstrItineraryData *Itin = TM.getInstrItineraryData();
   Top.HazardRec = TM.getInstrInfo()->CreateTargetMIHazardRecognizer(Itin, DAG);
   Bot.HazardRec = TM.getInstrInfo()->CreateTargetMIHazardRecognizer(Itin, DAG);
 
-  Top.ResourceModel = new VLIWResourceModel(TM);
-  Bot.ResourceModel = new VLIWResourceModel(TM);
+  Top.ResourceModel = new VLIWResourceModel(TM, DAG->getSchedModel());
+  Bot.ResourceModel = new VLIWResourceModel(TM, DAG->getSchedModel());
 
   assert((!llvm::ForceTopDown || !llvm::ForceBottomUp) &&
          "-misched-topdown incompatible with -misched-bottomup");
@@ -256,7 +258,8 @@ bool ConvergingVLIWScheduler::SchedBoundary::checkHazard(SUnit *SU) {
   if (HazardRec->isEnabled())
     return HazardRec->getHazardType(SU) != ScheduleHazardRecognizer::NoHazard;
 
-  if (IssueCount + DAG->getNumMicroOps(SU->getInstr()) > DAG->getIssueWidth())
+  unsigned uops = SchedModel->getNumMicroOps(SU->getInstr());
+  if (IssueCount + uops > SchedModel->getIssueWidth())
     return true;
 
   return false;
@@ -278,7 +281,7 @@ void ConvergingVLIWScheduler::SchedBoundary::releaseNode(SUnit *SU,
 
 /// Move the boundary of scheduled code by one cycle.
 void ConvergingVLIWScheduler::SchedBoundary::bumpCycle() {
-  unsigned Width = DAG->getIssueWidth();
+  unsigned Width = SchedModel->getIssueWidth();
   IssueCount = (IssueCount <= Width) ? 0 : IssueCount - Width;
 
   assert(MinReadyCycle < UINT_MAX && "MinReadyCycle uninitialized");
@@ -321,7 +324,7 @@ void ConvergingVLIWScheduler::SchedBoundary::bumpNode(SUnit *SU) {
 
   // Check the instruction group dispatch limit.
   // TODO: Check if this SU must end a dispatch group.
-  IssueCount += DAG->getNumMicroOps(SU->getInstr());
+  IssueCount += SchedModel->getNumMicroOps(SU->getInstr());
   if (startNewCycle) {
     DEBUG(dbgs() << "*** Max instrs at cycle " << CurrCycle << '\n');
     bumpCycle();
diff --git a/lib/Target/Hexagon/HexagonMachineScheduler.h b/lib/Target/Hexagon/HexagonMachineScheduler.h
index 5b6f226..fe0242a 100644
--- a/lib/Target/Hexagon/HexagonMachineScheduler.h
+++ b/lib/Target/Hexagon/HexagonMachineScheduler.h
@@ -45,7 +45,7 @@ class VLIWResourceModel {
   /// definition of DFA by a target.
   DFAPacketizer *ResourcesModel;
 
-  const InstrItineraryData *InstrItins;
+  const TargetSchedModel *SchedModel;
 
   /// Local packet/bundle model. Purely
   /// internal to the MI schedulre at the time.
@@ -55,29 +55,15 @@ class VLIWResourceModel {
   unsigned TotalPackets;
 
 public:
-  VLIWResourceModel(MachineSchedContext *C, const InstrItineraryData *IID) :
-    InstrItins(IID), TotalPackets(0) {
-    const TargetMachine &TM = C->MF->getTarget();
+VLIWResourceModel(const TargetMachine &TM, const TargetSchedModel *SM) :
+    SchedModel(SM), TotalPackets(0) {
     ResourcesModel = TM.getInstrInfo()->CreateTargetScheduleState(&TM,NULL);
 
     // This hard requirement could be relaxed,
     // but for now do not let it proceed.
     assert(ResourcesModel && "Unimplemented CreateTargetScheduleState.");
 
-    Packet.resize(InstrItins->SchedModel->IssueWidth);
-    Packet.clear();
-    ResourcesModel->clearResources();
-  }
-
-  VLIWResourceModel(const TargetMachine &TM) :
-    InstrItins(TM.getInstrItineraryData()), TotalPackets(0) {
-    ResourcesModel = TM.getInstrInfo()->CreateTargetScheduleState(&TM,NULL);
-
-    // This hard requirement could be relaxed,
-    // but for now do not let it proceed.
-    assert(ResourcesModel && "Unimplemented CreateTargetScheduleState.");
-
-    Packet.resize(InstrItins->SchedModel->IssueWidth);
+    Packet.resize(SchedModel->getIssueWidth());
     Packet.clear();
     ResourcesModel->clearResources();
   }
@@ -146,6 +132,7 @@ class ConvergingVLIWScheduler : public MachineSchedStrategy {
   /// of "hazards" and other interlocks at the current cycle.
   struct SchedBoundary {
     VLIWMachineScheduler *DAG;
+    const TargetSchedModel *SchedModel;
 
     ReadyQueue Available;
     ReadyQueue Pending;
@@ -166,7 +153,7 @@ class ConvergingVLIWScheduler : public MachineSchedStrategy {
     /// Pending queues extend the ready queues with the same ID and the
     /// PendingFlag set.
     SchedBoundary(unsigned ID, const Twine &Name):
-      DAG(0), Available(ID, Name+".A"),
+      DAG(0), SchedModel(0), Available(ID, Name+".A"),
       Pending(ID << ConvergingVLIWScheduler::LogMaxQID, Name+".P"),
       CheckPending(false), HazardRec(0), ResourceModel(0),
       CurrCycle(0), IssueCount(0),
@@ -177,6 +164,11 @@ class ConvergingVLIWScheduler : public MachineSchedStrategy {
       delete HazardRec;
     }
 
+    void init(VLIWMachineScheduler *dag, const TargetSchedModel *smodel) {
+      DAG = dag;
+      SchedModel = smodel;
+    }
+
     bool isTop() const {
       return Available.getID() == ConvergingVLIWScheduler::TopQID;
     }
@@ -197,6 +189,7 @@ class ConvergingVLIWScheduler : public MachineSchedStrategy {
   };
 
   VLIWMachineScheduler *DAG;
+  const TargetSchedModel *SchedModel;
   const TargetRegisterInfo *TRI;
 
   // State of the top and bottom scheduled instruction boundaries.
@@ -212,7 +205,7 @@ public:
   };
 
   ConvergingVLIWScheduler():
-    DAG(0), TRI(0), Top(TopQID, "TopQ"), Bot(BotQID, "BotQ") {}
+    DAG(0), SchedModel(0), TRI(0), Top(TopQID, "TopQ"), Bot(BotQID, "BotQ") {}
 
   virtual void initialize(ScheduleDAGMI *dag);